No el mic oemulsions wi h an
anionic/non-ionic su ac an mix u e
Disse a ion
zu E langung des akademischen G ades eines
Dok o s de Na u wissenscha en (D . e . na .)
de Fakul ä ü Biologie, Chemie und Geowissenscha en
an de Uni e si ä Bay eu h
o geleg on
Dipl.-Biochem. Uni .
Lukas Wol
Bay eu h,
Dezembe 2011
Die o liegende A bei wu de in den Jah en 2009 – 2011 in Bay eu h un e de Be euung on
He n P o . em. D . Heinz Ho mann in den Labo en de Fi ma BayColl im „Zen um ü
Neue Ma e ialien Bay eu h“, Wol sbach, du chge üh .
Volls ändige Abd uck de on de Fakul ä ü Biologie, Chemie und Geowissenscha en de
Uni e si ä Bay eu h genehmig en Disse a ion zu E langung des akademischen G ades eines
Dok o s de Na u wissenscha en (D . e . na .).
P omo ionsgesuch einge eich am: 07. Dezembe 2011
Zulassung du ch die P ü ungskommission: 14. Dezembe 2011
Tag des wissenscha lichen Kolloquiums: 17. Ap il 2012
Am ie ende Dekan:
P o . D . Bea e Lohne
P ü ungsausschuss:
P o . D . em. Heinz Ho mann (E s e Gu ach e )
P o . D . Yeshayahu Talmon (Zwei e Gu ach e )
P o . D . Ka lheinz Sei e (Vo si zende )
P o . D . S ephan Fö s e
„G undlagen o schung be eibe ich dann, wenn ich nich weiß, was ich ue.“
W. on B aun

Table o Con en s
7
0. Table o Con en s
Table o Con en s
0. TABLE OF CONTENTS....................................................................................................................................7
1. SUMMARY........................................................................................................................................................8
1.1. English Ve sion ...........................................................................................................................................8
1.2. Ge man Ve sion...........................................................................................................................................9
2. INTRODUCTION.............................................................................................................................................10
2.1. Mic oemulsions and hei applica ions......................................................................................................10
2.2. Phase beha iou o su ac an s ..................................................................................................................12
2.3. Mic oemulsions wi h non-ionic su ac an s...............................................................................................15
2.4. Mic oemulsions wi h ionic su ac an s......................................................................................................17
2.5. Objec i es o his hesis.............................................................................................................................19
3. SYNOPSIS........................................................................................................................................................21
3.1. The su ac an sys em Ca(DS)
2
/Mg(DS)
2
– IT 3........................................................................................21
3.2. Solubiliza ion o oil in o he su ac an mix u e ........................................................................................22
3.3. C yo-TEM imaging o he mic oemulsion sys em Ca(DS)
2
/IT 3 – H
2
O/M
2
.............................................24
3.4. Dynamic p ope ies o mic oemulsions in he single phase channels........................................................28
3.4.1. In oduc ion o he mic oemulsion sys em Mg(DS)
2
/IT 3 – H
2
O/decane ...........................................28
3.4.2. Elec ic bi e ingence and heology measu emen s...........................................................................30
3.5. C yo-TEM o mic oemulsions wi h a High In e nal Phase Mic oemulsion (HIPME) s uc u e ...............35
3.6. PFG-NMR sel di usion measu emen s....................................................................................................38
3.6.1. PFG-NMR sel di usion measu emen s in he single phase channels...............................................38
3.6.2. In luence o excess sal o he mic oemulsion sys em.........................................................................40
3.7. Ou look......................................................................................................................................................42
4. REFERENCES..................................................................................................................................................44
4.1. Li e a u e ...................................................................................................................................................44
4.2. Lis o igu es.............................................................................................................................................46
5. PUBLICATIONS..............................................................................................................................................47
5.1. O e iew o publica ions and indi idual con ibu ion...............................................................................47
5.1.1. Mic oemulsions om silicone oil wi h an anionic/nonionic su ac an mix u e................................49
5.1.2. C yo-TEM imaging o a no el mic oemulsion sys em o silicone oil wi h an anionic/nonionic
su ac an mix u e........................................................................................................................................60
5.1.3. Dynamic P ope ies o Mic oemulsions in he Single-Phase channels..............................................69
5.1.4. Mic oemulsions wi h a HIPME (High In e nal Phase Mic oemulsion) s uc u e .............................90
5.1.5. PFG-NMR in he Single Phase Channels o Mic oemulsions wi h an anionic/non-ionic su ac an
mix u e.........................................................................................................................................................98
6. ABBREVIATIONS AND SYMBOLS............................................................................................................109
7. PRESENTATIONS AT INTERNATIONAL MEETINGS.............................................................................110
8. ACKNOWLEDGEMENT...............................................................................................................................111
9. ERKLÄRUNG ................................................................................................................................................112
Summa y
8
1. Summa y
1.1. English Ve sion
Mic oemulsions consis o wa e , oil and su ac an . In con as o o dina y emulsions, mic oemulsions
a e anspa en and he modynamically s able phases. They appea o be mac oscopic single-phase
sys ems bu a e, howe e , based on highly complex nanos uc u es. F om he scien i ic poin o iew,
he so a mos s udied and bes unde s ood mic oemulsion sys ems consis o wa e , oil and ei he a
single non-ionic su ac an o an elec ically cha ged ionic su ac an . Bo h sys ems a e signi ican ly
di e en , o example in hei phase beha iou , he mal s abili y o hei nanos uc u es. Sys ems wi h
ionic/non-ionic su ac an mix u es, howe e , ha e no ye been in es iga ed in ensely.
In his wo k, he phase beha iou o an anionic/non-ionic su ac an mix u e wi h di e en oils was
in es iga ed. The phase diag ams exhibi wo op ically iso opic mic oemulsion egions wi h
inc easing oil con en a cons an empe a u e and su ac an concen a ion, he so called single phase
channels. The wo iso opic single phase channels a e sepa a ed by an op ically aniso opic phase
egion. The mic oemulsion channel below he aniso opic egion ex ends om he aqueous phase,
s a ing wi h inc easing oil concen a ion and inc easing mass ac ion o he non-ionic co-su ac an in
he su ac an mix u e o he middle o he phase diag am and ends he e. The uppe single phase
channel uns h ough a s eep minimum, wi h espec o he su ac an /co-su ac an a io, con inuously
om he aqueous o he oil- ich side o he phase diag am. In con as o mic oemulsions wi h single
non-ionic su ac an s, he mic oemulsion channels a e iso he mal. The di e en single-phase egions
we e examined wi h a ious physico-chemical me hods. The nanos uc u es could be iden i ied by
measu ing elec ic conduc i i y, SANS, PFG-NMR and by elec on mic oscopy. While he lowe
single phase channel consis s o small oil d ople s in a con inuous aqueous phase, which swell wi h
inc easing oil con en , he nanos uc u e in he uppe channel unde goes a complex s uc u al ansi ion.
The oil- ee sample, which has a bicon inuous sponge s uc u e, is ans o med o a wa e -in-oil
polyhed al oam s uc u e by solubilizing only a ew pe cen o oil. Fo his so a unknown
mic oemulsion s uc u e, we in oduced he e m high in e nal phase mic oemulsion (HIPME) due o
s uc u al simila i ies o he known high in e nal phase emulsions (HIPE). This complex s uc u al
ansi ion could be obse ed by ansien elec ic bi e ingence. The de e mined s uc u al elaxa ion
imes, which also de e mine he iscosi y o he luids, un h ough a sha p maximum a he ansi ion
poin om he bicon inuous o he w/o- oam s uc u es. The obse ed HIPME s uc u es a e p obably
caused by he p esence o he elec ic cha ge o he anionic su ac an . The elec ic cha ge on he
su ac an monolaye leads o a compa ably high in e acial ension be ween he dilu ed aqueous
su ac an phase and he oil. Consequences o his high in e acial ension a e oil con inuous
polyhed al oam s uc u es ins ead o bicon inuous s uc u es, which a e ob ained in simila
mic oemulsion sys ems wi h single non-ionic su ac an s. By shielding he elec ic cha ges by he
addi ion o sal , he oil con inuous HIPME s uc u es a e dis u bed wha can be concluded om an
inc eased conduc i i y and mobili y o he wa e ac ion, ollowed by NMR.
Summa y
9
1.2. Ge man Ve sion
Mik oemulsionen bes ehen im ein achs en Fall aus Wasse , Öl und Tensid(en). Es handel sich dabei im
Gegensa z zu no malen Emulsionen um anspa en e, he modynamisch s abile Phasen. Diesen
mak oskopisch einphasig e scheinenden Sys emen liegen jedoch hoch komplexe Nanos uk u en zu G unde.
Die in wissenscha liche Hinsich bislang am bes en un e such en und e s andenen
Mik oemulsionssys eme bes ehen en wede aus Wasse , Öl und einem einzigen elek isch ungeladenen
nich -ionischen Tensid ode einem elek isch geladenen ionischen Tensid. Beide Sys eme un e scheiden
sich g undlegend, un e ande em in ih em Phasen e hal en, ih e Tempe a u s abili ä ode ih en
Nanos uk u en. Sys eme mi Mischungen aus ionischen und nich ionischen Tensiden dagegen wu den
bishe kaum un e such .
Im Rahmen diese A bei wu de das Phasen e hal en eine anionischen/nich ionischen Tensidmischung mi
e schiedenen Ölen bei kons an e Tempe a u und kons an em Tensidgehal un e such . Die
Phasendiag amme weisen jeweils zwei op isch iso ope Phasengebie e, so genann e Einphasenkanäle, mi
s eigendem Öl-Gehal au . Die beiden Mik oemulsions-Einphasenkanäle sind oneinande du ch ein
op isch aniso opes Phasengebie ge enn . De Mik oemulsionskanal un e halb des aniso open Be eichs
e s eck sich on de wäss igen Phase ausgehend mi wachsendem Öl- und nich ionischen Co-Tensid-
An eil bis in die Mi e des Phasendiag amms und ende do . De obe e Einphasenkanal e läu du ch ein
s eiles Minimum, in Bezug au das Tensid/Co-Tensid e häl nis, du chgehend on de wäss igen zu
öl eichen Sei e des Phasendiag amms. Im Gegensa z zu Mik oemulsionen mi nich ionischen Tensiden
handel es sich um iso he me Einphasenkanäle. Die einphasigen Gebie e wu den mi di e sen physikalisch-
chemischen Me hoden un e such . Mi els Lei ähigkei s-, SANS-, PFG-NMR-Messungen und
elek onenmik oskopischen c yo-TEM Au nahmen konn en die Nanos uk u en iden i izie we den.
Wäh end im un e en Einphasenkanal die S uk u en aus kleinen Öl-T öp chen in eine kon inuie lichen
Wasse phase bes ehen, welche mi zunehmendem Öl-Gehal anschwellen, komm es im obe en
Einphasenkanal zu eine komplexen S uk u ände ung. Wäh end de öl eien P obe eine bikon inuie liche
Schwamms uk u zu G unde lieg , wandel sich diese mi be ei s wenigen P ozen an Öl zu eine
polyed ischen Wasse -in-Öl Schaums uk u . Fü diese, in Mik oemulsionen bislang unbekann en, S uk u
wu de de Beg i High In e nal Phase Mic oemulsion (HIPME) einge üh , au g und ih e s uk u ellen
Pa allelen zu be ei s bekann en High In e nal Phase Emulsionen (HIPE). Mi els ansien e
Elek odoppelb echung konn e diese komplexe s uk u elle Übe gang nach ollzogen we den. Die
e mi el en s uk u ellen Relaxa ionszei en, welche zudem die Viskosi ä de Mik oemulsionen bes immen,
weisen ein deu liches Maximum am Übe gangspunk on de bikon inuie lichen zu HIPME-S uk u au .
G und ü die beobach e e HIPME-S uk u is e mu lich de An eil de elek ischen Ladung des
anionischen Tensids. Diese so g ü eine e gleichba hohe G enz lächenspannung zwischen de wäss igen
e dünn en Tensid-Phase und des Öls. Konsequenz diese hohen G enz lächenspannung sind
ölkon inuie liche Schaums uk u en ans a bikon inuie liche S uk u en, welche man in e gleichba en
Mik oemulsionen mi ein nich ionischen Tensiden e häl . Du ch Abschi men de elek ischen Ladungen
mi Salz we den die HIPME-S uk u en ges ö , was sich in einem Ans eigen de Lei ähigkei und eine
e höh en Mobili ä de Wasse phase äuße , welche mi NMR beobach e wu de.
In oduc ion
16
The changing nanos uc u es can be easily ollowed by a s eady dec ease o he elec ic conduc i i y
wi hin he channel wi h inc easing mass ac ion o oil, when li le sal is added o he sys em.
33
The occu ence o he single-phase channel has o do wi h he change o he amphiphilic p ope ies o
he non-ionic su ac an as non-ionic su ac an s o he ype C
i
E
j
become mo e lipophilic wi h
inc easing empe a u e.
34
Wi h inc easing empe a u e, he cu a u e o he amphiphilic monolaye
changes om con ex o la and inally o conca e (Fig. 2.6). The eason o his lies in he sh inking
o he hyd ophilic head-g oups (EO-g oups). A low empe a u es, he size o he su ac an head
g oup is la ge han ha o he hyd ophobic chain, leading o an amphiphilic ilm cu ed a ound he oil.
By inc easing he empe a u e, he size o he EO-head g oup is sh inking, whe eas he size o
hyd ophobic chain inc eases due o he inc easing numbe o chain con o ma ions and he inc easing
pene a ion o oil molecules. These ends lead o a g adual change o he in e acial cu a u e.
35
As a
consequence he mic oemulsion s uc u es change, om he wa e side, om small oil d ople s in
wa e , o bicon inuous s uc u es in he middle o he phase diag am, o w/o d ople s on he oil side.
Fig. 2.6 Mean cu a u e H o a non-ionic su ac an ilm a he oil/wa e in e ace wi h inc easing empe a u e.
The size o he hyd ophilic EO-head g oup is sh inking whe eas he size o he liphophilic chain is inc easing by
aising empe a u e.
The in e acial ension be ween he oil and he wa e is a sensi i e pa ame e o he change o he
in e acial cu a u e. Op imum solubilisa ion o oil in a sys em wi h non-ionic su ac an s is ob ained
33
M. Kahlwei , e . al, J. Colloid In e . Sci 1987, 118, 450.
34
K.. Shinoda, P oceedings o he 5
h
In e na ional Cong ess o Su ace Ac i i y, Ba celona, Spain, Vol. 2, 1969,
275-283.
35
J. Lyklema, in: Fundamen als o in e ace and colloid science, Volume V: So Colloids, Academic P ess Inc,
2005.

In oduc ion
17
a he minimum o he in e acial ension o he dilu ed aqueous su ac an solu ion agains he oil.
36
Fo non-ionic su ac an s, ul a-low in e acial ensions agains he oil-phase a e obse ed ha can be
as low as 10
-3
mN/m. A ypical cu e o he change o he in e acial ension is shown in Fig. 2.7.
Fig. 2.7 Ul a low in e acial ension o he dilu ed non-ionic su ac an C
10
E
4
agains alkane oils wi h he chain
leng h k be ween 8 and 14.
Bicon inuous mic oemulsions a e ob ained in he egion o he minimum o he in e acial ension, as
low in e acial ensions allow non-sphe ical s uc u es due o he equilib ium in he in e acial
cu a u e.
2.4. Mic oemulsions wi h ionic su ac an s
The si ua ion in mic oemulsion sys ems wi h ionic su ac an is e y di e en compa ed o
mic oemulsions wi h non-ionic su ac an s. The p obably mos in es iga ed sys ems a e hose wi h
AOT (sodium di-2-e hylhexylsul osuccina e), decane, H
2
O and DDAB (didodecyldime hylammonium
b omide), dodecane, H
2
O.
37 , 38
The single phase egions in such sys ems a e usually plo ed in
iangula phase diag ams (Gibbs phase diag ams). An example o such a phase diag am o he
sys em DDAB, dodecane, H
2
O is shown in igu e 2.8. The iso opic phase egions (mic oemulsions) in
hese iangle p esen a ions a e e y di e en o hose o non-ionic su ac an s.
39
Sys ems wi h ionic
36
T. So mann and R. S ey, J. Chem. Phys. 1997, 106, 8606–8615
37
M. Ko la chyk, S.-H. Chen, J. S. Huang, M. W. Kim, Phys. Re . Le . 1984, 53, 941-944.
38
K. Fon ell, A. Ceglie, B. Lindman, B. Ninham, Ac a Chemica Scandina ica A40 1986, 247-256.
39
M. Kahlwei , R. S ey, Angew. Che n. In . Ed. Engl. 1988, 24, 654-668.
In oduc ion
18
su ac an s, which ha e been s udied usually, con ain la ge iso opic egions in he middle o he
iangle while phase diag ams wi h non-ionic su ac an s a e e y di e en and con ain na ow
iso opic channels. Howe e , mic oemulsion sys ems wi h single ionic su ac an s channels do no
ha e single phase channels ha pass om he aqueous side wi hou c ossing a phase bounda y
con inuously o he oil side o he phase diag am.
Fig. 2.8 Te na y phase diag am o he sys em DDAB, wa e and dodecane. The single phase mic oemulsion a ea
L
2
is indica ed as yellow.
The nanos uc u es o mic oemulsions wi h ionic su ac an s ha e been in es iga ed in de ail by SANS,
SAXS, elec ical conduc i i y and inally imaged by eeze ac u e elec on mic oscopy.
40
The esul s
showed ha he mo phology o he mic oemulsions o equal amoun s o wa e and oil is comple ely
di e en o hose o non-ionic su ac an s. Ins ead o a bicon inuous mic oemulsion phase, he e was
ound a wa e -in-oil d ople s uc u e. In Figu e 2.9, wo FF-TEM mic og aphs show he d ople
s uc u e o he sys ems AOT-decane-H
2
O and DDAB-dodecane-H
2
O. I is possible o dilu e hese
phases wi h oil wi hou he d ople s would change in size o s uc u e. The d ople s uc u e is caused
by he elec ic cha ges o he ionic su ac an ha esul in highe in e acial ensions compa ed o
mic oemulsion sys ems wi h non-ionic su ac an s. Howe e , i was shown by conduc i i y
expe imen s ha he oil-con inuous w/o-d ople s uc u es a equal amoun s o wa e and oil can be
ans o med o samples ha ha e simila bicon inuous ea u es as mic oemulsions wi h non-ionic
su ac an s by shielding he cha ge on he su ac an laye s by excess sal .
41
40
W. Jahn, R. S ey, J. Phys. Chem. 1988, 92, 2294-2301.
41
W. Sage , W. Sun, H.-F. Eicke, P og . Colloid Polym. Sci. 1992, 89, 284-287.
In oduc ion
19
Fig. 2.9 FF-TEM mic og aphs o w/o-mic oemulsions wi h ionic su ac an s a equal amoun s o wa e and oil.
Le mic og aph: d ople s uc u e o he sys em AOT (20 w %), decane and wa e , igh pic u e: agg ega ed
s uc u e o de o med d ople s o he sys em DDAB (13.9 w %), dodecane and wa e . Scale ba = 200 nm.
In addi ion, mic oemulsions om ionic su ac an s a e less sensi i e o empe a u e changes and s able
o e a wide empe a u e ange han mic oemulsions wi h non-ionic su ac an s, which quickly can
d op ou o phase when he empe a u e is no adjus ed accu a ely by a ew deg ees.
2.5. Objec i es o his hesis
Mic oemulsion sys ems wi h single non-ionic su ac an s and single ionic su ac an s a e in es iga ed
in de ail and well unde s ood. Howe e , he e a e only ew s udies o p ope ies o mic oemulsions
wi h mixed su ac an s. The beha iou o mix u es wi h di e en su ac an s is no easy o p edic , as
he empe a u e e ec on he solubili y and he phase beha iou o non-ionic and ionic su ac an s a e
e y di e en .
42
I should be no ed ha some esul s on he in luence o ionic su ac an s on phase
diag ams o non-ionic mic oemulsions ha e al eady been published.
43
I was obse ed ha he
iso opic channels we e widened by he in luence o ionic su ac an s and ha he su ac an e iciency
was inc eased.
44
Ne e heless, he e is no in o ma ion on he s uc u es o he iso opic channel, and
no de ailed phase diag ams o a ou -componen sys em we e es ablished.
42
H. Kunieda, K. Hanno, S. Yamaguchi, K. Shinoda, J. Colloid In e . Sci. 1985, 107, 129-137.
43
M. Kahlwei , B. Faulhabe , G. Busse, Langmui 1994, 10, 2528-2532.
44
J. A. Silas, E. W. Kale , Langmui 2001, 17, 4534-4539.
In oduc ion
20
As shown in 2.3, he e olu ion o he di e en mic oemulsion s uc u es in he single phase channel o
non-ionic su ac an s is based on he change o he in e acial cu a u e wi h empe a u e. I is known
ha he in e acial cu a u e can also be con olled by he in e acial composi ion, when a hyd ophilic
su ac an is mixed wi h a lipophilic co-su ac an .
45
Such a si ua ion is shown in Figu e 2.10.
Fig. 2.10 Change o he mean cu a u e H by mixing a hyd ophilic wi h a hyd ophobic su ac an . The dec ease
o H wi h inc easing amoun o he hyd ophobic su ac an in he composi ion o he in e ace δ
V,I
is caused by
he smalle head g oup o he hyd ophobic co-su ac an compa ed o he hyd ophilic su ac an .
The aim o his wo k was o es ablish a mic oemulsion sys em wi h a su ac an mix u e based on an
anionic hyd ophilic and a lipophilic co-su ac an and o p epa e a phase diag am o a ou -componen
sys em a cons an empe a u e. As i is well known ha he inc ease o empe a u e makes ionic
su ac an s mo e hyd ophilic while non-ionic su ac an s become mo e lipophilic
46
, i was hoped ha
hese bo h e ec s would compensa e in such a mic oemulsion sys em and he e o e esul in a sys em
ha is mos ly independen o empe a u e a ia ions. This is o g ea in e es o possible applica ions,
o example in he ield o cosme ic indus y o o he a eas like enhanced oil eco e y.
In addi ion, he simila i ies and he di e ences o such mixed sys ems compa ed o he basic non-ionic
o ionic mic oemulsion sys ems should be in es iga ed by di e en physicochemical me hods, as
conduc i i y, heology, PFG-NMR and elec on mic oscopy.
45
J. Reime , O. Söde mann, T. So mann, K. Kluge, R. S ey, Langmui 2003, 19, 10692-10702.
46
S. Aji h, A. K. Rakshi , J. Phys. Chem 1995, 99, 14778-14783.
Synopsis
21
3. Synopsis
3.1. The su ac an sys em Ca(DS)
2
/Mg(DS)
2
– IT 3
In he publica ion „Mic oemulsions om silicone oil wi h an anionic/non-ionic su ac an mix u e“,
we i s in oduced a new su ac an combina ion, ha u ned ou o be an in e es ing choice o he
p epa a ion o mic oemulsions. The main idea was o es ablish a mic oemulsion phase diag am in he
s yle o non-ionic mic oemulsion sys ems, in which iso opic mic oemulsion single phase channels
exis ha un om he aqueous side o he phase diag am o he oil-side wi hou passing a phase
bounda y. Ins ead o a ying he empe a u e o in luence he in e acial cu a u e o he su ac an
ilm, we wan ed o es ablish such single phase channels in an iso he mal mic oemulsion sys em by
adjus ing he mixing a io o wo di e en su ac an s, namely a hyd ophilic and a lipophilic one.
Al hough he idea o use su ac an mix u es o he p epa a ion o mic oemulsions is no new, no
de ailed phase diag ams wi h such a sys em ha e been in es iga ed ye . As hyd ophilic su ac an , we
chose calciumdodecylsul a e, as i was al eady known ha Ca
2+
-sal o SDS can o m lamella phases
and e en sponge-like phases, when i is mixed wi h sho chain alcohols as co-su ac an s. This is no
possible o no mal SDS. As lipophilic co-su ac an we chose an indus ial non-ionic su ac an ha is
based on a highly b anched iso idecanol which is e he i ied wi h an a e age numbe o h ee
e hylene-oxide g oups (iso idecyl ie hyleneglycole he , abb e ia ed as IT 3). By mixing bo h
su ac an s, we ecei ed a huge a ie y o di e en phases, s a ing by a micella L
1
phase wi h he
pu e Ca(DS)
2
, going o e o a la ge bi e ingen lamella a ea wi h inc easing mass ac ion o he
lipophilic co-su ac an and inally ending wi h a wo-phase si ua ion in ha he IT 3 is o ming
in e se micelles which a e sepa a ing om he lowe aqueous phase (Fig. 3.1). Rheological esul s
indica ed ha he lamella s uc u es change om mul ilamella esicles o plana lamellas wi h
inc easing mass ac ion o he lipophilic co-su ac an .
Fig. 3.1 Su ac an mix u es o Ca(DS)
2
( wo uppe ows) o Mg(DS)
2
(lowe ow) wi h inc easing mass ac ion
x o IT 3. Fi s ow shows su ac an mix u es wi h Ca(DS)
2
in di ec ligh . Second and hi d ows show samples
wi h Ca(DS)
2
and Mg(DS)
2
be ween c ossed pola ize s. Samples p epa ed wi h a o al su ac an concen a ion
o 15% (w/w), phases obse ed a T = 40 °C.

Synopsis
22
An amazing ea u e o he su ac an mix u e is he exis ence o an op ical iso opic L
3
sponge phase,
as L
3
phases wi h cha ged su ac an s a e e y a e.
When using he Ca(DS)
2
in he su ac an mix u e, one has o conside ha samples wi h high Ca(DS)
2
c ys allize a oom empe a u e due o i s high K a Tempe a u e o K
T
= 60 °C. The e o e we also
used he Mg
2+
-sal o SDS, as i has a lowe K
T
o 25 °C. Ne e heless, he su ac an phase sequence
as well as he p ope ies o he samples a e he same, when eplacing he Ca(DS)
2
by Mg(DS)
2
.
Ano he impo an esul in he publica ion is he obse a ion, ha he su ac an mix u e i sel has a
high in e acial ension in dilu ed aqueous solu ions agains oil. Fo mic oemulsion sys ems wi h non-
ionic su ac an s, ul a-low in e acial ensions a e epo ed. The high in e acial ensions o he mixed
su ac an sys em a e p obably caused by an in luence o he elec ic cha ges a he su ac an
monolaye . This u ned ou o ha e consequences o he nanos uc u e o he mic oemulsions ha
we e in es iga ed la e .
3.2. Solubilisa ion o oil in o he su ac an mix u e
In a nex s ep, we solubilized oil in o he su ac an mix u es o sea ch o iso opic mic oemulsion
a eas. As oil we chose he silicone oil hexame hyldisiloxane, as no mic oemulsion phase diag am wi h
silicone oil has been es ablished be o e. Ne e heless, we knew om p e ious solubilisa ion
expe imen s, ha hexame hyldisiloxane (M
2
) should beha e simila as decane. In igu e 3.2, he
di e en phases o he su ac an mix u es wi h inc easing amoun o oil in he sol en mix u e a e
summa ized in a phase diag am.
Fig. 3.2 Phase diag am o he sys em Ca(DS)
2
/IT 3 – H
2
O/M
2
wi h 15% (w/w) su ac an and 85% (w/w) sol en .
Phases obse ed a 40 °C. Abb e ia ion ‘‘ME’’ s ands o ‘‘mic oemulsion’’ and indica es a ea o iso opic
mic oemulsion channels.
Synopsis
23
All samples we e p epa ed wi h a cons an su ac an concen a ion o 15% (w/w) and he phase
beha iou was in es iga ed a 40 °C. Mos impo an esul s a e he p esence o wo iso opic
mic oemulsion single phase channels, which a e sepa a ed by a bi e ingen aniso opic a ea. The
uppe mic oemulsion channel ex ends om he aqueous side o he phase diag am con inuously o he
oil-side, while he lowe single phase channel ends in he middle o he phase diag am a equal
amoun s o wa e and oil.
As al eady men ioned, such mic oemulsion channels also exis in phase diag ams wi h single non-
ionic su ac an s, whe e he hyd ophilic-lipophilic balance is adjus ed by aising empe a u e. An
example o such a phase diag am wi h C
12
E
5
as su ac an and e adecane as oil is shown in igu e
3.3.
47
Fig. 3.3 Phase diag am o he sys em C
12
E
5
– H
2
O/Te adecane wi h cons an 16.6 w % su ac an . W
M
= wa e
con inuous mic oemulsion, O
M
= oil con inuous mic oemulsion, D = bicon inuous mic oemulsion, L.L.C =
lyo opic liquid c ys alline.
In such sys ems he nanos uc u e on he mic oemulsion changes wi h inc easing empe a u e and wi h
inc easing oil con en om oil-d ople s in a con inuous wa e phase o bicon inuous mic oemulsions a
equal amoun s o wa e and oil and inally o wa e -d ople s in a con inuous oil-phase a he oil- ich
47
U. Olsson, K. Shinoda, B. Lindman, Jou nal o Physical Chemis y, 1986, 90, 4083.
Synopsis
24
side o he phase diag am. The uppe channel ha s a s a he iso opic L
3
sponge phase a highe
empe a u e joins he lowe channel in he i s hal o he phase diag am.
An impo an di e ence be ween bo h shown phase diag ams is he ac , ha he mic oemulsion
channels a e no connec ed wi h each o he in he mixed anionic-non-ionic su ac an sys em.
Al hough mic oemulsions om bo h channels a e anspa en and op ical iso opic, samples in he
uppe single phase channel a e somewha bluish and show some shea induced bi e ingence wi h up
o 40% o oil in he sol en mix u e. This is a i s indica ion, ha he nanos uc u es in bo h channels
mus be e y di e en . Conduc i i y expe imen s inally ga e e idence, ha his is indeed he case.
While he conduc i i y alues in he lowe single phase channel s ayed abou he same, he e was
ound an ab up dec ease o he elec ical conduc i i y in he beginning o he uppe single phase
channel wi h only abou 5% o oil in he sol en mix u e. A equal amoun s o oil and wa e , no
conduc i i y could be de ec ed any longe . We concluded om he esul s, ha he nanos uc u e in he
uppe channel migh swi ch om a bicon inuous mo phology o a wa e -in-oil sys em, while he oil-in-
wa e s uc u es in he lowe channel emain he same wi h inc easing oil-concen a ion.
3.3. C yo-TEM imaging o he mic oemulsion sys em Ca(DS)
2
/IT 3 – H
2
O/M
2
To e i y he di e en nanos uc u es which we e concluded om he expe imen al esul s ha we e
p esen ed in he i s publica ion abou he new mic oemulsion sys em, we ied o image hem di ec ly
by c yogenic ansmission elec on mic oscopy (c yo-TEM) and discussed he esul s in a second
publica ion. In he c yo-TEM echnique, a small d ople o he sample is pipe ed on a pe o a ed
ca bon ilm ha is suppo ed by a TEM coppe g id. Wi h he help o a piece o il e pape , excess
liquid is blo ed away un il a hin liquid ilm wi h a desi ed a e age hickness o abou 200 nm is le
in he holes o he pe o a ed ca bon. A e blo ing, he specimen is plunged in o a sui ed c yogen o
i i ica ion. A e i i ica ion, he specimen is ans e ed unde liquid ni ogen in o he elec on
mic oscope. The specimen p epa a ion can be pe o med in a so called con olled en i onmen
i i ica ion sys em (CEVS), in which bo h he a mosphe e as well as he empe a u e can be
con olled.
48
This poin is e y impo an o he specimen-p epa a ion o empe a u e sensi i e
samples and/o samples ha con ain ola ile compounds.
Fo he p epa a ion o he wa e -con inuous samples, we used liquid e hane as c yogen as i p o ides
cooling- a es ha a e as enough o i i y H
2
O and no ice-c ys als should dis u b he image. The
imaging o he bina y su ac an sys em could be pe o med wi hou majo p oblems and he esul s
suppo ed he heological esul s. The c yo-TEM mic og aphs show a ansi ion om mul ilamella
esicles o plana lamellas wi h inc easing mass ac ion o IT 3 in he su ac an mix u e. We inally
obse ed he ansi ion om a lamella s uc u e o a bicon inuous ne wo k-s uc u e o he
neighbou ing L
3
phase (Figu e 3.4). As he c yo-TEM me hod only shows a wo-dimensional
48
Y. Talmon, in: “Seeing Gian Micelles by C yogenic-Tempe a u e T ansmission Elec on Mic oscopy (C yo-
TEM)”, in “Gian Micelles”, chap e 5, R. Zana, E. A. Kale , Eds., CRC P ess, New Yo k, 2007, 163-178.
Synopsis
25
p ojec ion o he a ious domains, he sponge-like cha ac e o he phase is no as well isible as wi h
o he me hods as eeze ac u e elec on mic oscopy, ha can ep oduce be e he h ee-dimensional
mo phology.
49
Tha is why he s uc u e seen on he c yo-TEM mic og aph could also be aken o a
ne wo k o h ead-like micelles ins ead o a bicon inuous sponge phase.
Fig. 3.4 C yo-TEM mic og aph o sample wi h 15% (w/w) su ac an Ca(DS)
2
/IT 3, x IT 3 = 0.77, p epa ed a
40 °C. Mic og aph shows bi-con inuous ne wo k-s uc u e o he L
3
phase.
The imaging o he mic oemulsion phases wi h he silicon oil was mo e challenging. Al hough we
ied o sa u a e he a mosphe e in he CEVS, i was o example no possible o image clea ly he
s uc u e o he mic oemulsions in he lowe single phase channel. Ins ead o iny mic oemulsion
d ople s, small unilamella esicles and also mul ilamella esicles we e mos ly imaged. The p oblems
wi h he sample p epa a ion we e ob iously caused by he high ola ili y o he sho chain silicone oil,
as elaxa ion expe imen s indica ed. Hexame hyldisiloxane has e apo a ion a es which a e
compa able o ace one. In such elaxa ion expe imen s, a ce ain amoun o ime is s opped a e he
blo ing-p ocedu e du ing c yo-TEM specimen p epa a ion, be o e he sample is plunged in o he
c yogen. The eby i can be in es iga ed i he nanos uc u e changes due o small changes in he
sample composi ion. In igu e 3.5, wo c yo-TEM mic og aphs o he same sample om he lowe
single phase channel wi h 15% o oil in he sol en mix u e a e shown. While he mic og aph o he
quickly p epa ed specimen shows s uc u es ha emind o oil-swollen micelles and some
mul ilamella esicles, he mic og aph o he specimen ha has been p epa ed wi h a delay o 30
seconds be o e he plunging shows collapsed s uc u es and la ge (mul ilamella ) esicles. The
49
H. Ho mann, C. Thunig, U. Munke , H. W. Meye , W. Rich e , Langmui 1992, 8, 2629-2638.
Synopsis
32
again. The inal p ocess is he longes wi h a elaxa ion ime o 14 ms. Simila complica ed signals
ha e been obse ed o elec ic bi e ingence measu emen s on dispe sion o clay pa icles. The
complica ed signals in hese sys ems a e due o he ac ha a ac ion o he pa icles align pa allel o
he elec ic ields, whe eas ano he ac ion aligns pe pendicula o he ield.
55
Fig. 3.11 EB-signal o a mic oemulsion o he uppe single phase channel wi h 6% decane in he sol en
mix u e. a) signal shown wi h ime sweep o 2 msec, b) signal wi h ime sweep o 100 msec, longes elaxa ion τ
L
= 14 msec. The signals iden i y h ee di e en elaxa ion p ocesses. Du a ion o elec ic pulse = 1 msec.
55
Y. Yamaguchi, H. Ho mann, Colloids Su . A 1997, 121, 67-80.
0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75 2,00
0,0
2,0x10
-8
4,0x10
-8
6,0x10
-8
8,0x10
-8
1,0x10
-7
1,2x10
-7
1,4x10
-7
1,6x10
-7
1,8x10
-7
2,0x10
-7
E- ield u ned o
τ
3
τ
2
E = 273 kVm
-1
∆
∆
∆
∆n
[msec]
τ
1
E- ield u ned on
τ
1
τ
2
a)
0 10 20 30 40 50 60 70 80 90 100
-2,0x10
-8
0,0
2,0x10
-8
4,0x10
-8
6,0x10
-8
8,0x10
-8
1,0x10
-7
1,2x10
-7
1,4x10
-7
1,6x10
-7
1,8x10
-7
2,0x10
-7
2,2x10
-7
∆
∆
∆
∆n
[msec]
E = 273 kVm
-1
τ
L
= 14 msec
b)

Synopsis
33
As he longes elaxa ion imes o he inal decay o he signal domina e o e he sho e imes, hey
we e called main s uc u al elaxa ion imes. Signals we e eco ded all along he uppe channel and he
main elaxa ion imes de e mined by analyzing he exponen ial decay o he inal p ocess. In addi ion,
he e was measu ed he ze o-shea iscosi y o he mic oemulsions. An o e iew o he main
s uc u al elaxa ion imes and he ze o shea iscosi ies in he uppe single phase channel can be
ound in igu e 3.12.
Fig. 3.12 Plo o he longes elaxa ion ime τ and he ze o shea iscosi y o mic oemulsions in he
uppe single-phase channel agains he mass ac ion o decane in he sol en mix u e.
The elaxa ion ime inc eases h ee o de s o magni ude and shows a maximum a ound 6-10% decane.
A he same ime, he ze o shea iscosi y inc eases wo o de s o magni ude. Wi h u he inc easing
mass ac ion o decane, he elaxa ion ime and he iscosi y dec ease again. The s uc u al elaxa ion
imes a ound he maximum ha we e de e mined by elec ic bi e ingence also could be de e mined by
heology.
As conduc i i y da a al eady implied, he e mus be a complex ansi ion mechanism om he
bicon inuous L
3
phase o a wa e -in-oil s uc u e wi h only a ound 6-10% oil. The complica ed signals
o mic oemulsions wi h low oil con en a e ob iously ela ed wi h his ansi ion mechanism and
show ha se e al mic os uc u es exis in he luid which a e in equilib ium wi h each o he . Fo
highe oil con en abo e 10% oil, EB-Signals become less complica ed again. This indica es ha he
s uc u al ansi ion is comple e. The s uc u al elaxa ion ime hen is dec easing again due o he
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8
0,1
1
10
0
100
200
300
400
500
Ze o-shea iscosi y [mPas]
x decane
|η*| [mPas]
τ[msec]
Relaxa ion ime τ[msec]
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8
0,1
1
10
0
100
200
300
400
500
Ze o-shea iscosi y [mPas]
x decane
|η*| [mPas]
τ[msec]
Relaxa ion ime τ[msec]
Synopsis
34
dec easing d ople size o he w/o d ople s wi h inc easing oil con en . The iscosi y maximum is also
he esul o a swi ch in he nanos uc u e om a low iscous lexible L
3
phase o a densely packed
w/o-HIPE s uc u e. Ob iously, he s uc u al elaxa ion ime con ols he iscosi y o he luid.
In he lowe single phase channel, simple elec ic bi e ingence signals we e ound ha a e caused by
he de o ma ion o d ople s in he elec ic ield. This indica es ha he nanos uc u e doesn’ change
much in his channel. Wi h inc easing mass ac ion o oil, he main s uc u al elaxa ion ime
inc eases wi h he iscosi y, as he d ople size inc eases (Figu e 3.13). The ini ial decay o he
iscosi y is due o he ans o ma ion o wo m-like micelles in bina y su ac an mix u e o sphe ical
micelles by solubilizing oil.
Fig. 3.13 Resul s o elec ic bi e ingence in he lowe single phase channel. a) EB-signal o a mic oemulsion
om he lowe single phase channel wi h 20% decane in he sol en mix u e. b) O e iew o main s uc u al
elaxa ion ime and ze o shea iscosi y wi h inc easing oil con en in he lowe single phase channel.
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0
-1,0x10
-8
0,0
1,0x10
-8
2,0x10
-8
3,0x10
-8
4,0x10
-8
5,0x10
-8
6,0x10
-8
7,0x10
-8
8,0x10
-8
x IT 3 0.45
x decane 0.2
∆
∆
∆
∆
n
[msec]
a)
0,00 0,05 0,10 0,15 0,20 0,25 0,30 0,35 0,40
0,01
0,1
1
10
x decane
τ
[msec]
η
[mPas]
η
η
η
η
[mPas]
τ
τ
τ
τ
[msec]
b)
10
100
Synopsis
35
3.5. C yo-TEM o mic oemulsions wi h a High In e nal Phase Mic oemulsion (HIPME)
s uc u e
As he conduc i i y and elec ic bi e ingence esul s showed he p esence o an oil-con inuous high
in e nal phase d ople s uc u e wi h less hen 10% o oil, c yo-TEM expe imen s we e pe o med o
image hese new mic oemulsion s uc u es di ec ly. The esul s we e published in a ou h manusc ip .
Un o una ely, oil con inuous phases wi h linea hyd oca bons like n-decane canno be in es iga ed by
c yo-TEM. Linea hyd oca bons end o c ys allize when hey a e quenched in o he liquid c yogen
du ing he specimen p epa a ion. B anched hyd oca bons, howe e , can be i i ied and do no
c ys allize. The e o e, we ied o add some iso-oc ane o he decane in o de o s ay as close as
possible o he decane sys em and hoped ha his would help o p e en he c ys alliza ion p ocess.
Good esul s c yo-TEM esul s o phases wi h linea oils ha we e mixed wi h b anched compounds
se ing as c yop o ec an s a e al eady epo ed.
56
C yo-TEM expe imen s wi h pu e decane/iso-oc ane mix u es ailed, i was no possible o gain
pic u es o clean i i ied oil- ilms. Ins ead, only da k c ys al s uc u es o he oil could be imaged,
ha we e sensi i e o he elec on beam and su e ed om i adia ion damage. As a consequence, we
ga e up he idea o use a mixed oil. A c yo-TEM mic og aph o such s uc u es is shown in igu e
3.14. The a io o n-decane/iso-oc ane was 7/3.
Fig. 3.14 C yo-TEM mic og aph o n-decane/i-oc ane, a io 7/3 (w/w), p epa ed a RT, c yogen: liquid ni ogen.
In ano he s udy, he sponge s uc u e o a bicon inuous mic oemulsion wi h a single non-ionic
su ac an was al eady success ully imaged by c yo-TEM. The sample was p epa ed wi h he
56
D. Danino, R. Gup a, F. Sa aya olu, Y. Talmon, J. Colloid In e . Sci. 2002, 249, 180-168.
Synopsis
36
su ac an C
12
E
5
, iso-oc ane, H
2
O and had a wa e /oil a io (w/w) o 7/3. The mic og aphs clea ly show
a sponge s uc u e wi h ypical dimensions o wa e and oil domains a ound 0.2 µm.
Mic oemulsions o he new mixed su ac an sys em he e o e we e p epa ed wi h pu e iso-oc ane o
c yo-TEM in es iga ions ins ead o decane. Fo una ely, he mic oemulsion samples om he uppe
channel showed he same p ope ies as samples wi h decane. The same ab up dec ease o he
conduc i i y as well as he maximum o he iscosi y a ound 6-10% o oil was ound. Mo eo e , i
was no necessa y o adjus he su ac an /co-su ac an a io o ob ain single phase mic oemulsions,
he phase composi ion was abou he same.
While he c yo-TEM pic u es o he L
3
phase wi hou oil showed he well-known bicon inuous
ne wo k-s uc u es, he si ua ion changes d as ically when only 6% o iso-oc ane a e solubilized in o
he phase. In Figu e 3.15, mic og aphs o he mic oemulsion om he uppe channel wi h 6% o iso-
oc ane in he sol en mix u e a e shown.
Fig. 3.15 C yo-TEM mic og aphs o a mic oemulsion om he uppe single phase channel wi h 15% su ac an
Mg(DS)
2
/IT 3, x IT 3 0.62, x iso-oc ane 0.06, quenched om 25 °C.
They clea ly show a densely packed w/o-d ople s uc u e, which look like a “polyhed al oam” ha
has hin ilms wi h a hickness o abou 3 nm. The diame e o he wa e domains is abou 50 nm. The
hin ilm was ob iously made o he su ac an s wi h he hyd oca bon in be ween he wo monolaye s,
and he wa e inside he polyhed a. The s uc u es look e y much like he s uc u es ound in high
in e nal phase emulsions (HIPE). HIPEs a e concen a ed sys ems wi h a la ge olume o he dispe sed
phase. Those high olume ac ions esul in he de o ma ion o d ople s in o polyhed a, which a e
sepa a ed by hin ilms o he con inuous phase. In such si ua ions he size o he s uc u es a e usually
in he ange o se e al µm and can easily be seen by ligh mic oscopy. Bo h o/w and w/o-sys ems o
Synopsis
37
HIPEs a e known.
57
Based on ha , we call he newly ound mic oemulsion s uc u e HIPME (High
In e nal Phase Mic o-Emulsion). Such s uc u es ha e so a only been obse ed in eal emulsions ha
a e, like any o he emulsions, he modynamically uns able.
58
In he mic oemulsion sample wi h he
HIPME s uc u e, he wa e domains a e no connec ed wi h each o he . This can be concluded om
he ac ha he ice-c ys als in da k ha e he same size as he ice c ys als in g ey. In spi e o hei small
oil con en , he HIMPE phases ha e a conduc i i y ha is abou 3 - 4 o de s o magni ude lowe han
he conduc i i y o he L
3
phase. The hin su ac an ilms a e p ac ically impene able o he anspo
o ions, explaining he low conduc i i y o he sample. Mic oemulsions wi h a HIPME s uc u e we e
imaged success ully all along he uppe single phase channel (Fig. 3.16).
Fig. 3.16 C yo-TEM mic og aphs o a mic oemulsion wi h a HIPME s uc u e. Le : sample con aining 30% o
iso-oc ane, igh : sample con aining 50% o iso-oc ane in he sol en mix u e.
The HIPME s uc u es a e ob iously he esul o he elec ic cha ges in he su ac an laye s,
con ibu ed by he anionic Mg(DS)
2.
They cause high in e acial ensions, leading o sphe ical
s uc u es ins ead o a bicon inuous mo phology. I is likely, ha ansi ions o bicon inuous s uc u es
can be p o oked by shielding he elec ic double-laye s in ionically cha ged sys ems by excess sal .
57
N. R. Came on, D. S. She ing on, Ad . Polym. Sci. 1996, 126, 163-214.
58
H. Ho mann, G. Ebe , Angewand e Chemie 1988, 27, 902-912.

Synopsis
38
3.6. PFG-NMR sel di usion measu emen s
To unde line and o e i y he p e iously ob ained esul s, he mic oemulsion channels we e
in es iga ed by pulsed- ield g adien nuclea magne ic esonance spec oscopy (PFG-NMR). This
me hod is a special echnique, based on nuclea magne ic esonance spec oscopy (NMR). In con as
o no mal NMR measu emen s, inhomogeneous magne ic ields a e used. Wi h he help o addi ional
magne ising coils, line ield-g adien s a e gene a ed and hus locally changing magne ic ields. This
allows pe o ming spa ially esol ing NMR expe imen s, in which local in o ma ion can be ob ained
like he posi ion o he mo emen o pa icles, which a e isible o NMR. The e o e, PFG-NMR can
gi e de ailed in o ma ion abou he s uc u e, luidi y and emulsion ype bu also indica ions abou he
in e ac ion be ween su ac an and co-su ac an a he in e ace. Mo e de ails abou he PFG-NMR
me hod can be ound in li e a u e.
59
In a i h publica ion, he esul s o PFG-NMR expe imen in he
mic oemulsion single phase channels a e epo ed. In addi ion, he in luence o excess sal o he
sys em was in es iga ed by in e acial ension, conduc i i y and NMR-measu emen s, as we ied o
ans o m a high in e nal phase mic oemulsion o a bicon inuous mic oemulsion by shielding he
elec ic cha ges o he anionic su ac an .
3.6.1. PFG-NMR sel di usion measu emen s in he single phase channels
The PFG-NMR analysis is ocussed on hose spec al egions which can ei he be clea ly assigned o
single sys em cons i uen s (wa e and decane) o o he mix u e o he su ac an s (Mg(DS)
2
/IT 3). The
in eg als o hese h ee spec al egions s ongly depend on he s eng h o he g adien pulse, he eby
indica ing he a e age displacemen o he co esponding sys em cons i uen s du ing he pe iod
be ween he pulses which was se o 50 ms. In a plo o he loga i hmic signal in ensi y s. he
pa ame e γ²G²δ²(∆-δ/3) (wi h γ being he gy omagne ic a io o p o ons, G he s eng h o he g adien
ield, δ and ∆ he du a ion o and he spacing be ween he wo g adien pulses), he slope is equal o
he nega i e appa en sel di usion coe icien o he gi en componen in he he e ogeneous sys em
(S ejskal-Tanne plo ). I he componen is loca ed in wo di e en en i onmen s leading o clea ly
di e en sel di usion p ope ies, he plo will show wo sec ions wi h clea ly di e en slopes. I he
componen is encapsula ed in e y small d ople s, he mo ion wi hin he d ople s becomes
unde ec able. In his case, he obse ed slope e lec s he eloci y o he B ownian mo ion o he
d ople s.
In Figu e 3.17, a S ejskal-Tanne plo o wa e and he su ac an in he L
3
phase is shown. The wa e
signal ollows a s eep decay, co esponding o a sel di usion cons an ha is jus sligh ly lowe han
he alue o ee bulk wa e . This indica es ha wa e o ms a con inuous phase ha is only sligh ly
a ec ed by phase bounda ies o he su ac an laye s. In con as , he signal o MDS/IT3 ollows a
ela i ely la decay. This means he e is only a es ic ed mobili y o he Mg(DS)
2
and IT3 molecules.
59
P. Hei jans, J. Kä ge , eds., in: Di usion in condensed ma e : me hods, ma e ials, models, Sp inge Ge many,
2005, 421.
Synopsis
39
Fig. 3.17 S ejskal-Tanne plo o wa e and he su ac an s in he L
3
phase.
The si ua ion changes signi ican ly when decane is added o he sys em. The mobili y o wa e is much
educed. In con as , he di usion a es o decane exhibi alues which come close o he bulk
di usion a e o decane. In his si ua ion, he sel di usion cons an o he wa e ac ion is oo small
o be assigned o bulk wa e in a con inuous phase. This shows ha he obse ed wa e molecules a e
encapsula ed in small d ople s which unde go B ownian mo ion in he con inuous decane phase.
In Figu e 3.18, he di usion cons an s o H
2
O in he uppe single phase channel a e summa ized wi h
inc easing decane con en .
Fig. 3.18 Sel di usion cons an s o H
2
O in he uppe mic oemulsion channel as a unc ion o he decane con en .
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7
1x10
-10
2x10
-10
3x10
-10
4x10
-10
5x10
-10
6x10
-10
7x10
-10
8x10
-10
di [m
2
/s]
% (x decane)
di [m/s]
0,60
0,65
0,70
0,75
0,80
0,85
0,90
sample composi ion
x IT 3
a )
0,0 5,0x10
10
1,0x10
11
-10
-8
-6
-4
-2
0
wa e
MDS/IT 3
ln I/I
0
γ
2
G
2
δ
2
(
∆
-
δ
/3)
0% decane (uppe chanel)
a )
Synopsis
40
The da a o he sel di usion coe icien s o wa e show a clea co ela ion wi h he co esponding
conduc i i y plo ha was shown in Fig. 3.8.
In con as o he esul s o he uppe channel, he a ia ions be ween he PFG-NMR esul s o
di e en posi ions in he lowe channel do no indica e d ama ic s uc u al changes. The da a esemble
hose o he uppe channel in absence o decane. All in all, he da a a e clea ly in acco dance wi h o/w
mic oemulsions.
3.6.2. In luence o excess sal o he mic oemulsion sys em
As al eady men ioned in 3.1, ou mixed anionic/non-ionic su ac an sys em has a e y high in e acial
ension agains he oil phase. In case o he mic oemulsion sys em wi h decane, he minimum
in e acial ension o 2.5 mN/m is eached a a su ac an /co-su ac an a io o 1:1. In non-ionic
mic oemulsion sys ems, ul a low alues as 1
.
10
-3
mN/m a e eached. We assumed ha by shielding
he cha ge o he anionic su ac an by adding excess sal would lowe he in e acial ension. Simila
e ec s we e al eady epo ed o he anionic su ac an die hylhexyl sodium sulphosuccina e (AOT),
whe e ul a-low in e acial ensions agains oil we e eached wi h addi ional NaCl.
60
Ne e heless, he in e acial ension couldn’ be lowe ed signi ican ly in ou sys em, no ul a-low
in e acial ensions we e de ec ed when excess NaCl was added o he su ac an mix u es. Howe e ,
he uppe and lowe bo de s o he single phase egions a e shi ed o lowe x IT 3 alues by x IT 3 ~
0.07 when NaCl is added o he Mg(DS)
2
in a mola a io o 1:1. The shi o lowe x IT 3 alues
means ha he sys em in o al becomes mo e lipophilic, as less amoun o he lipophilic co-su ac an
IT 3 in he su ac an mix u e is needed o solubilize he oil. By measu ing he elec ic conduc i i y o
a mic oemulsion wi h 30% o decane wi h inc easing sal concen a ion, i was checked i he shi o
he phase bounda ies migh also accompanied by a change in he in e nal nanos uc u e o he
mic oemulsion sample. A plo o he conduc i i y in he single phase egion wi h inc easing NaCl
concen a ion is shown in igu e 3.19. The conduc i i y om he NaCl- ee o he mic oemulsion wi h
a mola a io o Mg(DS)
2
:NaCl = 1:1 inc eases abou h ee o de s o magni ude om a low alue o 3
µS/cm o ~ 1000 µS/cm. The conduc i i y inc eases in a sigmoid cu e wi h an in lec ion poin a ound
50% NaCl and no linea ly wi h inc easing NaCl concen a ion. A i s look i seems like he
nanos uc u e changes om a w/o-HIPME sys em o a bicon inuous-like nanos uc u e.
60
R. A eya d, B. P. Binks, S. Cla k, J. Mead, J. Chem. Soc. Fa aday T ans. 1 1986, 82, 125-142.
Synopsis
41
Fig. 3.19 Plo o conduc i i y in he single phase egion o a mic oemulsion wi h x decane 0.3 and inc easing
NaCl concen a ion a 25 °C. 100% NaCl co esponds o a mola a io o Mg(DS)2:NaCl = 1:1.
To p oo his, we compa ed wo mic oemulsions wi h di e en sal concen a ions by PFG-NMR. The
i s sample wi hou NaCl had he composi ion o x IT 3 0.7 and x decane 0.3. The second sample had
he composi ion o x IT 3 0.615, x decane 0.3, and he mola a io o Mg(DS)2:NaCl = 1:1 (Fig. 3.20).
Fig. 3.20 S ejskal-Tanne plo s o decane and wa e o a mic oemulsion om he uppe single phase channel
wi h 30% decane in he sol en mix u e. a) plo o mic oemulsion wi hou excess NaCl, b) plo wi h excess NaCl.
The mobili y o wa e is much educed in he sample wi hou NaCl. When NaCl is added o he sys em,
he mobili y o wa e is inc easing. Ne e heless, he di usion a e is much slowe compa ed o he
bicon inuous L
3
phase (Fig. 3.17) whe e i is close o bulk wa e . The di usion beha iou o decane
doesn’ change wi h NaCl. The e o e we conclude, ha he main s uc u e s ill is p esen as HIPME-
phase.
0 10 20 30 40 50 60 70 80 90 100
1
10
100
1000
conduc i i y [µS/cm]
sample composi ion
NaCl [%]
conduc i i y [µS/cm]
0,61
0,62
0,63
0,64
0,65
0,66
0,67
0,68
0,69
0,70
x IT3
0,0 5,0x10
10
1,0x10
11
-10
-8
-6
-4
-2
0
wa e peak
decane peak
ln I/I
0
γ
2
G
2
δ
2
(
∆
-
δ
/3)
p obe wi hou NaCl
a )
0,0 5,0x10
10
1,0x10
11
-10
-8
-6
-4
-2
0 wa e peak
decane peak
ln I/I
0
γ2
G
2δ2
(
∆
-
δ
/3)
p obe con ains NaCl
b )
Publica ions
48
 Mic oemulsions wi h a HIPME (High In e nal Phase Mic oemulsion) s uc u e
Published in Jou nal o Physical Chemis y B, 2011 by Lukas Wol *, Heinz Ho mann, Takashi
Teshigawa a, Toh u Okamo o, Yeshayahu Talmon. DOI:.
*co esponding au ho
 PFG-NMR Sel Di usion Measu emen s in he Single Phase Channels o a Mic oemulsion
Sys em wi h an anionic/non-ionic Su ac an Mix u e
Submi ed o So Ma e in Decembe 2011 by Lukas Wol *, Heinz Ho mann, Jü gen Linde s
and Ch is ian Maye .
* co esponding au ho
cu en s a us: unde e ision

Mic oemulsions om silicone oil wi h an anionic/non-ionic su ac an mix u e
49
5.1.1. Mic oemulsions om silicone oil wi h an anionic/non-ionic su ac an mix u e
Lukas Wol *, Heinz Ho mann*, Kei Wa anabe and Toh u Okamo o
*co esponding au ho
Published in Physical Chemis y Chemical Physics 2011, 13, 3248-3256.
DOI: 10.1039/C0CP00062K.
3248 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 This jou nal is c he Owne Socie ies 2011
Ci e his:
Phys. Chem. Chem. Phys
., 2011, 13, 3248–3256
Mic oemulsions om silicone oil wi h an anionic/nonionic su ac an
mix u ew
Lukas Wol ,*
a
Heinz Hoffmann,*
a
Kei Wa anabe
b
and Toh u Okamo o
b
Recei ed 30 h Ma ch 2010, Accep ed 2nd Decembe 2010
DOI: 10.1039/c0cp00062k
Mic oemulsion phases ha e been p epa ed o he fi s ime om he silicone oil ‘‘M
2
’’
(hexame hyldisiloxane) and a su ac an mix u e o a nonionic su ac an ‘‘IT 3’’
(iso idecyl ie hyleneglycole he ) and an ionic su ac an Ca(DS)
2
(calciumdodecylsul a e).
Fo such a su ac an mix u e he hyd ophilici y o he sys em can be uned by he mixing a io
o he wo componen s. Wi h inc easing IT 3 con en , he su ac an mix u es show a L
1
-phase,
a wide L
a
- egion and a na ow L
3
sponge phase. Fo cons an empe a u e, wo single phase
channels exis in he mic oemulsion sys em. The lowe channel (low IT 3 con en ) ends in he
middle o he phase diag am wi h equal amoun s o wa e and oil, he uppe channel begins wi h
he L
3
-phase and passes all he way o he oil phase. Conduc i i y da a show ha he uppe
channel has a bi-con inuous mo phology up o 40% oil while he lowe channel consis s o oil
d ople s in wa e . In con as o p e ious s udies on nonionic sys ems, he wo single phase
channels a e no connec ed and mic oemulsions wi h equal amoun o oil and wa e do no ha e
a bicon inuous s uc u e.
In oduc ion
Mic oemulsions (ME) a e he modynamically s able fluids
ha consis o oil, wa e and a ew pe cen o su ac an .
1
They usually a e low iscous, mo e o less anspa en and
op ically iso opic liquids. Mic oemulsions a e used in many
applica ions because o hei ascina ing p ope ies. One o he
easons o hei use ulness is ha bo h pola and apola
compounds can be dissol ed in mic oemulsions. They a e
he e o e used o ag ochemical, cosme ic, pha maceu ical
and o he indus ial o mula ions whe e i is necessa y o
b ing wo componen s in a fluid oge he which no mally a e
no miscible. De ailed in es iga ions on mic oemulsions o e
he las 40 yea s ha e shown ha he componen s o he fluids
a e no dispe sed wi h each o he on a molecula le el like in
miscible sol en mix u es bu he fluids a e highly s uc u ed
on a scale o 1–100 nm. Domains o oil and wa e , wi h well
defined in e aces om su ac an s, al e na e wi h each o he .
These domains a e in equilib ium wi h each o he and a e e y
dynamic in beha iou . They cons an ly change hei shape and
size on a ime scale o mic o- o milliseconds. Today, he basic
beha iou o nonionic mic oemulsions is well unde s ood on
he basis o heo e ical models in which he mean cu a u e o
in e aces,
1
he bending cons an s o su ac an monolaye s
2
and he in e acial ension be ween oil and wa e
3
play
a cen al ole. Depending on he composi ion o he fluids
he s uc u es in he fluids can be oil swollen micelles
(o/w-mic oemulsions), bicon inuous s uc u es o wa e swollen
in e se micelles (w/o-mic oemulsions).
Mic oemulsions can be p epa ed ei he om nonionic o
om ionic su ac an s.
2–6
The single phase egions in sys ems ha consis o oil, wa e
and su ac an s a e usually plo ed in iangula phase
diag ams.
The iso opic phase egions (mic oemulsions) in hese
iangle p esen a ions a e e y diffe en o ionic su ac an s
and o nonionic su ac an s.
7,8
Sys ems wi h ionic su ac an s,
which ha e been s udied usually, con ain la ge iso opic
egions in he middle o he iangle while phase diag ams
wi h nonionic su ac an s a e e y diffe en and con ain
na ow iso opic channels.
9
Fo cons an su ac an concen-
a ion, hese channels usually pass om he aqueous side
wi hou c ossing a phase bounda y con inuously o he oil side
o he phase diag am.
De ailed phase diag ams wi h many diffe en sys ems in
which he oil and he su ac an s we e a ied ha e shown ha
wo channels exis in mic oemulsions wi h nonionic su ac an s
and wi h a iable empe a u e.
10
The wo channels a e
connec ed wi h each o he in he middle o he phase diag am
and he phase egion in be ween he channels con ains an
L
a
-phase. Small angle neu on sca e ing measu emen s ha e
a
Uni e si y o Bay eu h, BZKG/BayColl, Go lieb-Keim-S . 60,
95448 Bay eu h, Ge many. E-mail: heinz.hoff[email p o ec ed],
[email p o ec ed]
b
Shiseido Resea ch Cen e , 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama,
Japan 224-8558. E-mail: [email p o ec ed]
wElec onic supplemen a y in o ma ion (ESI) a ailable: Tes ube
pic u es o he es ablished phase diag am. See DOI: 10.1039/
c0cp00062k
PCCP
www. sc.o g/pccp PAPER
50
This jou nal is c he Owne Socie ies 2011 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 3249
shown ha he micella s uc u es in he low empe a u e
channel e ol e om globula o/w s uc u es, ans o m o
bicon inuous s uc u es in he c oss-o e egion and change
con inuously o globula w/o s uc u es in he high empe a u e
channel.
11
The s uc u es in he uppe channel a e o a
bicon inuous na u e igh om he aqueous side.
12
The goal o his in es iga ion was o p epa e mic oemulsions
om he highly ola ile silicone oil hexame hyldisiloxane
(M
2
), wa e and a nonionic/anionic su ac an mix u e.
Mic oemulsions om se e al silicone oils and nonionic
su ac an s ha e al eady been published.
13
Bu as a as we
know, a phase diag am wi h he silicone oil M
2
had no ye
been p epa ed and in es iga ed in de ail. I was known
howe e ha M
2
beha es simila ly in solubilisa ion expe imen s
as decane.
14
Viscoelas ic solu ions wi h wo mlike micelles a e
ans o med o low iscous micella solu ions wi h he same
mola amoun o decane o o M
2
. The sa u a ion concen a ion
o bo h oils is also abou he same. I could he e o e be
expec ed ha mic oemulsions om M
2
can be o med and he
phase diag am wi h M
2
should look simila o decane o he
same su ac an sys em. To achie e ou goal, a mixed non-
ionic/anionic su ac an sys em was used. This sys em had
o be op imized o he empe a u e egion a which he
mic oemulsion was o be p epa ed.
Su ac an s o he o ma ion o mic oemulsions can be
op imized by in e acial ension measu emen s.
15
Maximum
solubilisa ion occu s when he in e acial ension o a dilu e
su ac an solu ion has i s lowes in e acial ension agains he
oil phase.
16
Fu he mo e i is known ha low in e acial
ensions a e obse ed o su ac an sys ems which o m
liquid c ys alline L
a
-phases o L
3
-phases a low su ac an
concen a ions o a ew pe cen .
17
Ideal su ac an sys ems o
he o ma ion o mic oemulsions can he e o e be ecognised
based on hei phase beha iou .
18
Ionic su ac an s like sodiumdodecylsul a e a e e y
hyd ophilic and do no gi e L
a
-phases when mixed wi h wa e
soluble nonionic su ac an s. The si ua ion is imp o ed when
Na
+
-ions a e eplaced by bi alen Ca
2+
-ions. P e ious
in es iga ions had shown ha in mix u es o SDS and e a-
decyldime hylaminoxide he L
1
-phase could be ans o med
o a L
a
-phase simply by subs i u ing he Na
+
-ions by
Ca
2+
-ions.
19
Solu ions o Ca(DS)
2
on hei own a e s ill
L
1
-phases in which wo mlike micelles a e p esen .
20
I such
solu ions a e mixed wi h nonionic compounds ha a e
gene ally used as co-su ac an s one ob ains L
a
-phases in a
wide composi ion egion. As a co-su ac an he nonionic
su ac an IT 3 (iso idecyl ie hyleneglycole he ) was used.
I is comme cially p oduced and is wo ldwide a ailable unde
he name ‘‘Ma lipal O13/30’’ as o he well-known nonionic
su ac an s like ‘‘T i on X 100’’.
21
The compound is a highly
b anched iso idecanol, e he ified wi h a e age 3 EO-g oups.
Despi e i s polydispe si y, i ac s mos ly like a pu e su ac an
o he obse ed phases.
In a gene al sense he op imum condi ion o mic o-
emulsions o a pa icula empe a u e can be adjus ed by
mixing a hyd ophilic su ac an ha o ms a L
1
-phase and a
lipophilic su ac an ha is no soluble in he aqueous phase
bu o ms i s own L
2
-phase.
22
The used su ac an mix u e in
ou s udy hus consis s o an ionic su ac an ha is jus a bi
oo hyd ophilic o o m a L
a
-phase and a co-su ac an ha is
a bi oo lipophilic o o m a L
a
-phase on i s own. The
combina ion o he wo su ac an s o ms a L
a
-phase o e a
wide su ac an composi ion. Fo he aim o his p ojec , we
used his su ac an -sys em which could o m L
a
-phases and
hope ully would o m mic oemulsions o silicone oils.
I should be no ed ha some esul s on he influence o ionic
su ac an s on phase diag ams o nonionic mic oemulsions
ha e al eady been published.
23
I was obse ed ha he iso opic channels we e widened by
he influence o ionic su ac an s. The e was howe e no
in o ma ion on he s uc u es o he iso opic channel.
As a as we know, ou in es iga ions on he desc ibed
mic oemulsion esul s a e eally he fi s wi h a de ailed phase
diag am ha had been es ablished wi h a nonionic/ionic
su ac an mix u e. Some o he esul s u ned ou o be
su p ising and could no ha e been expec ed on he basis o
p e ious esul s. The main no el ea u es a e: an L
3
-phase wi h
an anionic/nonionic su ac an mix u e, a mic oemulsion wi h
equal amoun s o oil and wa e ha canno ha e a bicon inuous
s uc u e and wo iso opic channels ha a e no connec ed.
Resul s and discussion
The su ac an mix u es
In Fig. 1, samples o mix u es o wo su ac an s a e shown
ha ulfil he c i e ia desc ibed in he In oduc ion. The
su ac an s a e Ca- o Mg-dodecyl sul a e (Ca(DS)
2
,o
Mg(DS)
2
) and iso idecyl ie hyleneglycole he IT 3. The
Ca- o Mg-sal s can be easily p epa ed om sodiumdodecyl-
sul a e, and IT 3 is comme cially a ailable. Ca(DS)
2
has a high
K aff - empe a u e o K
T
=501C and can he e o e only be
used a highe empe a u es o a oom empe a u e, when
he K aff - empe a u e has been educed by he second
componen o oom empe a u e.
24
Mg(DS)
2
has a lowe
K aff - empe a u e o K
T
=251C. Fig. 1 shows h ee ows
o samples o he su ac an mix u es.
The fi s wo ows con ain samples o Ca(DS)
2
wi h inc easing
mass ac ion o IT 3. The o al concen a ion is cons an a
15% (w/w) and empe a u e is a 40 1C. The lowe ow o he
wo shows he same samples be ween c ossed pola ize s and a
hi d ow shows samples wi h Mg(DS)
2
and IT 3 again wi h
pola ize s.
The Ca(DS)
2
/IT 3 mix u es con ain c ys alline p ecipi a es
up o a mass ac ion o xIT 3 = 0.4. The samples om
xIT 3 = 0.5 o 0.75 a e bi e ingen and con ain a highly
swollen L
a
-phase. The sample wi h xIT 3 = 0.8 is op ically
iso opic and has a low iscosi y. I is a L
3
-phase. The L
3
-phase
can be ecognised based on i s mic os uc u e om c yo-TEM
measu emen s.
25
Su p isingly, he samples wi h an e en highe
mass a io o IT 3 con ain wo phases wi h a L
a
-phase as he
la ge olume ac ion. Fo no mal beha iou o hyd ophilic
and lipophilic mix u es one would ha e expec ed o find
mul iphase egions wi hou an L
a
-phase.
26
I is concei able
ha he wo componen s a e no longe miscible in bilaye s
and phases a e o med wi h diffe en mixing a ios. I is
no ewo hy o men ion ha in he combina ion o Ca(DS)
2
and IT 3 a sample wi h a wo phase L
a
/L
3
-si ua ion could no
51
3250 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 This jou nal is c he Owne Socie ies 2011
be obse ed when he composi ion o he samples was a ied
in small s eps. This is shown in Fig. 2. E en o he condi ion
when he composi ion was a ied s epwise one pe cen by one
pe cen he samples we e wi hin he single L
a
-phase egion
o in he single L
3
-phase egion. The samples wi h he
Mg(DS)
2
/IT 3 mix u es o m mo e o less he same phases
as he Ca(DS)
2
mix u es.
The mix u es wi h xIT 3 = 0.1 and 0.2 a e iscous single
phase egions o an op ically iso opic L
1
-phase and he
sample wi h xIT 3 = 0.3 is a L
1
/L
a
wo phase sample.
The samples wi h xIT 3 = 0.8 show again a L
3
-phase, and
he sample wi h xIT 3 = 0.9 con ains a wo phase egion wi h
one phase being a L
a
-phase. I is ema kable ha he mix u es
wi h ionic su ac an s o m a L
3
-phase.
27
Many in es iga ions
ha e shown ha neu al L
3
-phases a e ans o med o
L
a
-phases when small ac ions o he su ac an s a e eplaced
by ionic su ac an s.
28
The exis ence o he L
3
-phase in he
in es iga ed sys em is p obably linked o he ac ha he
bi- alen me al-ions bind s ongly o he dodecylsul a e and
he su ac an s show only weak dissocia ion. These su ac an s
beha e he e o e e y simila like nonionic su ac an s.
While he exis ence o he L
3
-phase in he used sys em
a xIT 3 = 0.76 is unexpec ed, i is no ewo hy ha such a
phase had also been obse ed in he phase diag am o Ca(DS)
2
wi h oc anol o lowe chain leng h alcohols.
24
In his
in es iga ion i was u he mo e shown ha he L
3
-phase
disappea ed when 10% o he Ca(DS)
2
was eplaced by
SDS. Wha was e en mo e su p ising was he appea ance o
aL
a
-phase o co-su ac an a ios well abo e he exis ence
egion o he L
3
-phase. These obse a ions show ha he
obse ed sequence o phases o he p esen sys em canno
be due o he ac ha he used co-su ac an IT 3 is no a pu e
and single componen bu mus be caused by he bi alen
coun e -ions. The expe imen al beha iou u he mo e poin s
ou ha he heo e ical unde s anding o mul icomponen
sys ems lea es much o be desi ed. Mo e expe imen al esul s
in combina ion wi h heo e ical models a e necessa y o come
o a be e unde s anding o such complex sys ems.
Su ace and in e acial ension measu emen s
The samples wi h he highes solubilisa ion capaci y should be
samples wi h he lowes su ace o in e acial ension alues.
These pa ame e s we e he e o e measu ed o a 0.5%
su ac an solu ion as a unc ion o he mixing pa ame e .
Plo s o he su ace ension measu emen s a e shown in
Fig. 3A o he Ca(DS)
2
/IT 3 sys em, and in Fig. 3B o he
in e acial ension alues o he Mg(DS)
2
/IT 3 sys em agains
he silicone-oil hexame hyldisiloxane.
The lowes su ace ension (sE26.4 mN m
1
) is ob ained
a xIT 3 = 0.55 while he lowes in e acial ension is ob ained
a xIT 3 = 0.4 wi h gE4mNm
1
. These measu emen s
confi m ha he samples, ha ha e a composi ion in he ange
o a L
a
-phase, ha e indeed low sand g alues. I should be
no ed howe e ha he in e acial ension be ween he oil and
wa e phases in he p esence o nonionic su ac an s, ha
esul s in he o ma ion o mic oemulsions, is usually in he
ange o 1 10
3
mN m
1
.
29
Tha is h ee o de s o
magni ude lowe . I is concei able ha his diffe ence comes
om he ac ha he used su ac an mix u e con ains an
Fig. 1 Su ac an mix u es o Ca(DS)
2
( wo uppe ows) o Mg(DS)
2
(lowe ow) wi h inc easing mass ac ion xo IT 3. Fi s ow shows
su ac an mix u es wi h Ca(DS)
2
in di ec ligh . Second and hi d ows show samples wi h Ca(DS)
2
and Mg(DS)
2
be ween c ossed pola ize s.
Samples p epa ed wi h a o al su ac an concen a ion o 15% (w/w), phases obse ed a T=401C.
Fig. 2 Su ac an mix u e Ca(DS)
2
/IT 3 wi h xIT 3 0.75–0.77, 15%
su ac an (w/w), shown a 401C be ween c ossed pola ize s.
52
This jou nal is c he Owne Socie ies 2011 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 3251
ionic su ac an and he cha ges we e no shielded by excess
sal . Su ac an phases wi h an ionic su ac an and excess sal
can ha e ex emely low in e acial ension agains he oil phase
as obse ed by C. A. Mille e al.
30
The in e acial ension o
double chain su ac an s, which ha e been used o he
p epa a ion o mic oemulsions, agains oil is also in he ange
o 0.1–1 mN m
1
.
31
I is concei able ha he highe in e acial
ensions o he cha ged su ac an sys ems a e he eason
o he diffe en beha iou o he in es iga ed sys em om
mic oemulsions wi h nonionic su ac an s.
Rheological esul s
The phases wi h diffe en mixing a ios o he wo componen s
ha e diffe en heological p ope ies. The pu e Mg(DS)
2
-
solu ion is al eady a iscous ‘‘shea hinning solu ion’’. The
L
a
-phases a e iscoelas ic phases wi h a yield s ess alue.
They ha e al eady a weak gel-cha ac e . The L
3
-phase finally
is a low iscous New onian solu ion. Rheog ams o samples in
he L
a
- egion a 40 1C we e measu ed and a e shown in Fig. 4.
A a mass ac ion o 0.5 (Fig. 4A), he s o age modulus G0
uns abo e he loss modulus G00 a a le el o 100 Pa and is
independen o he equency a a shea s ess o = 5 Pa.
Wi h inc easing mass ac ion o IT 3, he le el o G0fi s keeps
cons an a 100 Pa a xIT 3 = 0.6, and hen d ops o B8Paa
xIT 3 = 0.7 a E0.1 Pa, bu is s ill independen o
(Fig. 4C). The decay o he s o age modulus G0wi h
inc easing mass ac ion o IT 3 and he ac ha G0b eaks
in a lowe shea s ess show ha he L
a
-phase looses i s gel-
like cha ac e wi h inc easing xIT 3. A xIT 3 = 0.75,
measu ed a E0.2 Pa (Fig. 4D), G0inc eases in he double
Fig. 3 Su ace ension o he su ac an sys em Ca(DS)
2
/IT 3 (A) and
in e acial ension o he su ac an sys em Mg(DS)
2
/IT 3 agains
silicone oil hexame hyldisiloxane (B), measu ed a 25 1C, su ac an
concen a ion 0.5% (w/w).
Fig. 4 Rheog ams o samples in he L
a
- egion, su ac an sys em Ca(DS)
2
/IT 3, su ac an concen a ion 15% (w/w), measu ed a 40 1C. (A) xIT
3 = 0.5, measu ed a = 5 Pa. (B) xIT 3 = 0.6, measu ed a = 5 Pa. (C) xIT 3 = 0.7, measu ed a = 0.1 Pa. (D) xIT 3 = 0.75, measu ed
a = 0.2 Pa.
53

3252 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 This jou nal is c he Owne Socie ies 2011
log plo wi h a slope o 2 while G00 inc eases wi h a slope o
one, indica ing ha he L
a
-phase los mos o i s gel-like
cha ac e . By eason o he heological esul s, we assume a
s uc u al change in he L
a
-phase om mul ilamella esicles
o plana lamellas wi h inc easing xIT 3.
The change o he heological p ope ies om he L
a
o he
L
3
-phase by a e y small change o he bina y su ac an
mix u e is one o he mos s a ling effec s in su ac an
science. In he p esen si ua ion, he diffe ence o he
p ope ies o he wo phases is especially la ge because one
o he componen s is ionically cha ged. Bu e en o sys ems
wi h nonionic su ac an s and co-su ac an s he diffe ences
be ween he wo phases a e ema kable.
18
I should be
men ioned ha bo h phases consis o bilaye s uc u es.
The o igin o he huge change in he heological and o he
p ope ies lies in he o ma ion o passages be ween adjacen
bilaye s when he L
3
-phase is app oached.
32
Solubilisa ion o hexame hyldisiloxane (M
2
) in he diffe en
su ac an mix u es
The su ac an mix u es wi h 15% (w/w) o su ac an and a
diffe en mixing a ios we e used o solubilise inc easing
amoun s o oil. Pho os o es ubes o samples be ween
c ossed pola ize s can be seen in he ESI.wThe phase beha iou
o he samples was plo ed in a phase diag am (Fig. 5). The
special ea u es o he diag am a e wo iso opic phase
channels, a lowe channel ha begins a he wa e side a
xIT 3 = 0.1 and a highe channel ha begins a ound
xIT 3 = 0.8, he mass ac ion o he L
3
-phase. The uppe
channel fi s dec eases wi h inc easing oil con en and hen
inc eases slowly wi h u he inc ease in oil con en o he oil
co ne . The lowe channel inc eases smoo hly and seems o
end in he middle phase egion. In be ween he wo channels
a e single phase L
a
- egions o mul iphase egions wi h one
phase being a L
a
-phase. The phase diag am shows ha i is
possible in su ac an mix u es o obse e single phase
channels o a cons an empe a u e o each om he wa e
side o he oil side. Such channels ha e no ye been obse ed
o one componen su ac an sys ems. Unde such condi ions
he empe a u e has o be changed o obse e he single phase
channel. While he co-su ac an con en in he lowe phase
channel is inc easing wi h inc easing oil con en , i is he o he
way a ound o he uppe phase channel. In his case he
co-su ac an con en passes h ough a minimum.
An in e es ing consequence o his beha iou is ha he
single L
3
-phase, whe e he channel begins, is ans o med o e
a mul iphase egion wi h inc easing oil solubilisa ion in o he
uppe phase mic oemulsion wi h 30% o oil. I is no ewo hy
ha p elimina y esul s wi h decane as oil ha e shown a
simila beha iou . The shape o he channel o iso he mal
condi ions is hus a consequence o he used su ac an
mix u e and no o he oil. O gene al in e es on he phase
diag am is also he ac ha wi h inc easing solubilisa ion o
he oil in o he L
a
-phase, he wides ex ension o he L
a
-phase
is in he middle o i s exis ence egion. A his composi ion he
L
a
-phase can solubilise mo e han i s own weigh o oil, be o e i
Fig. 5 Phase diag am o he sys em Ca(DS)
2
/IT 3–H
2
O/M
2
wi h 15% (w/w) su ac an and 85% (w/w) sol en . Phases obse ed a 40 1C.
Abb e ia ion ‘‘ME’’ s ands o ‘‘mic oemulsion’’ and indica es a ea o iso opic mic oemulsion channels.
54
This jou nal is c he Owne Socie ies 2011 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 3253
b eaks down. The high con en o oil in a L
a
-phase is howe e
no a special ea u e o he used oil o he su ac an mix u e.
O he mic oemulsion phase diag ams ha e been epo ed wi h
L
a
-phases ha con ain mo e oil han su ac an and whe e he
su ac an is a nonionic su ac an .
33
I is howe e in e es ing o
no e ha such L
a
-phases exis ha consis o wo monolaye s o
su ac an ha encloses he oil in be ween he monolaye s and
he whole package is like a sandwich.
The mul iphase egion be ween he wo channels
The mul iphase egion be ween he wo iso opic channels is e y
la ge and domina es he phase diag am. I ex ends o 45% o oil
on he oil axis. O he phase diag ams o mic oemulsions wi h
nonionic su ac an s do no ha e such a la ge mul iphase egion.
In he su ac an composi ion egion be ween xIT3=0.2and
0.55 he wo phase egions a e he L
a
/L
1
- egion. The L
a
-phases
on he wa e side a e ans o med wi h inc easing amoun o oil
in o wo phase egions and finally in o he single phase channel.
The amoun o oil ha is necessa y o des oy he L
a
-phase
inc eases wi h he mass ac ion o IT 3 in he su ac an mix u e.
I is in e es ing o no e ha he su ac an phase wi h xIT 3 =
0.55 can accommoda e mo e han i s own weigh o oil be o e
some o he L
a
-phase is ans o med o a mic oemulsion phase.
Close o he uppe channel, he si ua ion is mo e
complica ed.
Mos in e es ing a e he sequence o phases in he su ac an
composi ion be ween xIT 3 = 0.6 and 0.7. Wi h xIT 3 = 0.6,
he L
a
-phase is ans o med wi h 5% o oil in o he wo phase
L
a
/ME egion and wi h 20% o oil he sys em e-en e s he
single L
a
-phase. Fo highe oil a ios he sys em app oaches
he lowe single phase channel in a wo phase L
a
/ME egion.
Wi h xIT 3 = 0.65, he phase diag am becomes e en mo e
complica ed. Wi h 5% oil, he L
a
-phase is ans o med in o
he uppe iso opic channel. In he oil egion be ween 20% and
40%, a wo phase egion wi h he L
a
-phase and an iso opic
phase exis s, in which he L
a
-phase fi s inc eases wi h he oil
con en and hen dec eases again (see ube pic u es o samples
in ESIw). I is likely ha he iso opic phase in he wo phase
egion fi s is a ME om he uppe phase channel while i is a
ME om he lowe phase channel in he second egion.
An e en diffe en si ua ion is obse ed wi h xIT 3 = 0.7.
The pu e L
a
-phase is again ans o med wi h li le oil in o he
bi-con inuous channel. Wi h mo e oil, mul iphase egions a e
obse ed ha ha e no L
a
- egion.
The sea ch o a connec ion o bo h single phase channels
We we e su p ised no o find a connec ion be ween he lowe
and he uppe single phase channel as would ha e been expec ed
om known phase diag ams wi h nonionic su ac an s. The
eason o his could ha e been ha he composi ion o he
in es iga ed samples was no close enough o de ec he
connec ion. To sea ch o a possible connec ion be ween bo h
single phase channels, mo e samples be ween bo h channels we e
in es iga ed. Fig. 6 shows a ow o samples ha ha e been
p epa ed by mixing di ec ly a sample om he end o he lowe
single phase channel wi h a sample om he uppe single phase
channel.
The fi s mixed sample wi h a composi ion o xIT 3 = 0.675
and xM
2
= 0.46 is al eady a wo phase sample wi h a lowe
L
a
-phase and an uppe iso opic phase. While we did no
analyse he uppe phase, i looked like i consis s o pu e M
2
.
This esul is a s ong indica ion o exis ing ie lines be ween
he L
a
-phase and pu e M
2
. I would mean ha an iso opic
channel canno exis in be ween he lowe and he uppe single
phase channel.
In he ollowing samples, he olume o he L
a
-phase dec eases
and he olume o he uppe phase inc eases, a sign ha he
dis ance o he composi ion o he sample is inc easing om he
L
a
-phase and dec easing om he uppe phase. Wi h he six h
sample wi h he composi ion xIT 3 = 0.775 and xM
2
=0.5, he
si ua ion changes comple ely. The sample clea ly consis s now o
h ee phases, a lowe L
a
-phase, a middle bluish mic oemulsion
phase and an uppe oil phase. This h ee-phase a ea is ollowed
by a wo phase a ea wi h a dec easing lowe L
a
-phase and an
uppe bluish mic oemulsion phase. Wi h xIT 3 = 0.85 and xM
2
= 0.53, he sample eached he uppe iso opic single phase
channel. Mo e samples wi h his h ee phase si ua ion we e
ound and d a ed as a iangle in he phase diag am (Fig. 5).
This h ee phase a ea indica es ha he e canno be a connec ion
o bo h single phase channels.
The p ope ies o he samples in he single phase channels
I is e iden om isual inspec ion o he samples ha he
s uc u e o wo samples wi h he same amoun o oil bu a
diffe en su ac an a ios is no he same. An o e iew o
Fig. 6 Mix u es o a sample om he lowe and uppe single phase channels o he sys em Ca(DS)
2
/IT 3–H
2
O/M
2
wi h xM
2
= 0.45 and
xM
2
= 0.55. Uppe ow shows samples wi hou c ossed pola ize s, lowe ow shows samples in be ween c ossed pola ize s a 40 1C.
55
3254 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 This jou nal is c he Owne Socie ies 2011
samples in he uppe and lowe single phase channels wi h
inc easing amoun o oil is shown in Fig. 7.
Samples om he uppe phase channel (Fig. 7A) a e
somewha bluish and he sca e ing in ensi y o he samples
inc eases om he wa e co ne o samples wi h 65% o
oil. Samples wi h la ge oil con en sca e less. All samples
om he lowe phase channel sca e much less (Fig. 7B).
Samples om he uppe channel show flow bi e ingence up o
40% oil, while he samples om he lowe channel do no
show flow bi e ingence. These ea u es a e a fi s indica ion
ha he uppe channel has a bi-con inuous s uc u e while
he lowe channel consis s o oil d ople s in a con inuous
wa e phase. The s uc u es o he mic oemulsions in he
channels a e now al eady epo ed
36
and he physicochemical
p ope ies like hei heology and hei s uc u al elaxa ion
imes will be gi en in ano he manusc ip . I also will be
shown ha he ob ained phase diag am changes only li le
i M
2
is eplaced by decane. The ob ained esul s a e hus
ypical o mic oemulsion phase diag ams wi h mixed
nonionic/ionic su ac an mix u es. The empe a u e s abili y
o he samples in bo h channels hasn’ been in es iga ed
in de ail, bu i was obse ed ha he samples in he lowe
single phase channel we e less sensi i e o empe a u e
changes han he samples in he uppe single phase channel,
especially close o he L
3
-phase. This can be explained by he
highe mass ac ion o a empe a u e sensi i e nonionic
su ac an in he uppe channel. Ne e heless, all samples
a e s able in a wide empe a u e ange han samples wi h
nonionic su ac an mix u es ha a e only s able wi hin
a ound 11C.
Fig. 7 O e iew o selec ed samples in he uppe (A) and lowe (B) single phase channel o he sys em Ca(DS)
2
/IT 3–H
2
O/M
2
a 40 1C.
Fig. 8 Conduc i i y measu emen s in he uppe (A) and lowe (B) single phase channel o he sys em Ca(DS)
2
/IT 3–H
2
O/M
2
a 40 1C.
56
This jou nal is c he Owne Socie ies 2011 Phys. Chem. Chem. Phys., 2011, 13, 3248–3256 3255
Conduc i i y measu emen s
Fo conduc i i y measu emen s, all samples ha e been
p epa ed wi h 10 mM NaCl. A plo o he conduc i i y in he
wo channels agains he weigh ac ion o oil is gi en in Fig. 8.
No e ha he conduc i i ies in he lowe channel (Fig. 8B) a e
much highe a he wa e co ne han hose in he uppe channel
(Fig. 8A). The eason o his is ha he Ca(DS)
2
concen a ion is
much highe in he lowe channel. I he conduc i i ies a e
no malized o he same Ca(DS)
2
concen a ion hey a e abou
he same. The conduc i i ies dec ease linea ly wi h he oil con en
o he middle o he phase diag am, which is whe e he channel
ends. The eason o he dec ease is mainly he dec easing mass
ac ion o Ca(DS)
2
. The conduc i i ies he e o e indica e ha
he mic os uc u e in he lowe channel does no change and ha
he channel consis s o a con inuous wa e phase in which oil
d ople s a e dispe sed.
The si ua ion is diffe en in he uppe channel. In his channel
he conduc i i y d ops o a ew pe cen o oil (5%) o only abou
18% o i s alue in he L
3
-phase e en hough he ac ion o
Ca(DS)
2
is inc easing om 23% o 35%. Fo highe mass
ac ion o oil he conduc i i ies emain abou cons an and d op
o ze o o xM
2
= 0.4. The conduc i i ies hus indica e a
d ama ic change in he mic os uc u e o he bi-con inuous
channel wi h solubilisa ion o small amoun s o oil in o he
L
3
-phase. Ob iously he cons ain s in he mic oemulsion o
he anspo o he ions mus be much la ge han hose in he
L
3
-phase. This means ha he wa e channels in he ME-phase
mus be much smalle han hose in he L
3
-phase whe e he
conduc i i y is only abou 2/3 o he alue o he no mal aqueous
phase wi hou a su ac an . The comple e b eak-down o he
conduc i i y o oil ac ions la ge han 0.4 means ha he
sys em changes om a bi-con inuous s uc u e o a w/o-s uc u e.
Conduc i i ies in he iso opic channels o mic oemulsions om
nonionic su ac an s ha e been epo ed in he li e a u e.
34
In he
uppe channel he epo ed conduc i i ies dec ease con inuously
wi h inc easing oil con en . These measu emen s ha e helped o
es ablish he iew which we ha e oday om he s uc u es in he
uppe channel. Wi h inc easing oil con en he bicon inuous
L
3
-phase swells wi h he solubilised oil be ween he bilaye s
and is finally ans o med a high oil con en o a w/o sys em.
Wi h equal amoun o oil and wa e bo h SAXS-da a and
conduc i i ies show ha his phase is s ill a bicon inuous
phase.
35
Ou conduc i i y measu emen s unambiguously show
ha he s uc u es in he uppe channel o he in es iga ed
sys em a e diffe en om he s uc u es o known sys ems wi h
nonionic su ac an s. We find a a he ab up ansi ion
om he L
3
-s uc u e o ano he bicon inuous s uc u e wi h
swollen aqueous channels a a ound 10% o oil and ano he
ab up ansi ion a 40% o oil o a w/o s uc u e.
The mic oemulsion wi h equal amoun o oil and wa e does
no ha e a bicon inuous s uc u e. In he mean ime, his has
been confi med by c yo-TEM images, which show clea ly a
w/o-s uc u e.
36
Finally, a he end o he discussion we would like o
d aw a en ion o se e al expe imen al obse a ions which
ha e been made du ing his in es iga ion and which o ou
knowledge a e no heo e ically unde s ood and need u he
scou ing. To men ion he e a e he exis ence o he L
3
-phase in
he anionic nonionic su ac an mix u e, he occu ence o a
second L
a
- egion a e he exis ence o he L
3
-phase and a
s uc u al ansi ion in he bi-con inuous uppe phase channel.
Conclusion
The e na y phase diag am o he silicone oil hexame hyl-
disiloxane M
2
, wa e and a su ac an mix u e o he ionic
su ac an Ca(DS)
2
and he nonionic su ac an iso idecyl-
ie hyleneglycole he IT 3 has been es ablished as a unc ion
o he mass ac ion o IT 3.
Two iso opic single phase channels occu in he sys em wi h
inc easing oil con en xM
2
. The lowe channel, ha is he one
wi h he lowe xIT 3 alue, begins a he phase bounda y o
he L
1
-phase owa d he L
a
-phase. This channel inc eases wi h
inc easing xM
2
and ends in he middle o he phase diag am a
xIT 3 = 0.65. This channel con ains oil d ople s in a
con inuous wa e phase (o/w-sys em). The uppe channel
begins a he L
3
-phase and passes wi h inc easing oil con en
h ough a shallow minimum o he oil side. I has, like he
L
3
-phase, a bi-con inuous s uc u e un il 40% oil, and hen
swi ches o a w/o s uc u e o he oil side. The mic oemulsion
wi h equal amoun o wa e and oil does no ha e a bicon inuous
s uc u e. Phases o bicon inuous s uc u e show a s ong flow
bi e ingence. Samples om he o/w and he w/o channel a e
anspa en and show no flow bi e ingence.
In con as o phase diag ams wi h one componen , su ac an
mix u es wi h su ac an s can o m channels ha pass om he
wa e o he oil side a cons an empe a u e. The amphiphilic
p ope ies o he channels can be adjus ed by changing he
composi ion o he su ac an mix u e ins ead o he empe a u e.
The uppe channel and he lowe channel a e no connec ed
wi h each o he . I is likely ha he non-connec i i y is due o he
influence o he ionic su ac an and he high in e acial ension o
he su ac an sys em agains oil, which p omo es he o ma ion
o globula s uc u es ins ead o a bicon inuous opology.
In o al, he in es iga ion has shown ha mic oemulsion
phase diag ams, ha a e es ablished wi h mix u es o an
anionic and a nonionic su ac an s, diffe om he phase
diag am ha can be p oduced wi h ionic o wi h nonionic
su ac an s. We p opose ha he si ua ion in ou sys em is
somewhe e be ween and o gene al impo ance.
Expe imen al
Ma e ials
Sodiumdodecylsul a e (SDS, c ys . esea ch g ade) was
pu chased om he Se a Co., Heidelbe g. The nonionic
su ac an iso idecyl ie hyleneglycole he , in he ollowing
ex abb e ia ed as IT 3, was ob ained om he Sasol Co.,
Hambu g (p oduc name Ma lipal O13/30). MgCl
2
6H
2
O and
CaCl
2
2H
2
O we e pu chased om he G u
¨ssing Co., Filsum.
The silicone oil hexame hyldisiloxane, abb e ia ed as M
2
,
was ob ained as a gi om he Wacke Co., Mu
¨nchen.
P epa a ion o Ca(DS)
2
and Mg(DS)
2
Fo he p epa a ion o Ca(DS)
2
and Mg(DS)
2
, 400 mM SDS-
solu ions we e mixed wi h ei he 200 mM CaCl
2
o MgCl
2
57
is no so clea ly seen in he c yo-TEM p epa a ion as he h ee
dimensional na u e o he bilaye ne wo k. The c yo-TEM
mic og aph in Fig. 5 ac ually looks somewha like a wo
dimensional p ojec ion o a h ee dimensional polyhed al oam.
The L
3
-phase is o med only in he e y na ow composi ion o
he samples wi h xIT 3 ¼0.76 o 0.77. In he neighbou ing
L
a
-phase wi h a composi ion o xIT 3 ¼0.75 he s uc u es a e
e y di e en .
Fo compa ison wi h he mic os uc u e o he L
3
-phase,
mic og aphs a e shown in Fig. 6 o a sample wi h a sligh ly
di e en composi ion, namely wi h xIT 3 ¼0.75.
The mic og aphs show he ypical pa e n o a L
a
-phase in
which he bilaye s a e pe pendicula o he su ace o he hin
ilm (Fig. 6A). The in e lamella spacing is o he o de o
10–15 nm and he bilaye hickness is abou 3 nm. The mic o-
g aphs o he L
3
-phase and he L
a
-phases a e e y consis en wi h
each o he . On close inspec ion o he mic og aphs o he
L
a
-phase one is able o see de ec s in some egions (Fig. 6B).
These de ec s a e indica ed on he mic og aphs o Fig. 6B wi h
whi e a ows.
One no es si ua ions whe e wo adjacen bilaye s seem o be
connec ed by b idges. These could be he s uc u es ha ha e
been heo e ically p edic ed.
18
I is no ewo hy ha he mic o-
g aph in Fig. 6A looks like a inge p in wi h a much la ge scale.
I is somewha su p ising ha he bilaye s in he hin ilms a e all
pe pendicula o he ilm su ace. F om op ical mic oscopy, in
con as , i is known ha he bilaye s a e e y o en aligned
pa allel o he ilm su ace, wha is known unde homeo opic
alignmen . The eason o he di e en si ua ion ha is shown in
Fig. 6 may be a esul o he ilm hickness. In he holes o he
polyme ilms he hickness o he su ac an phase a ies. On
pa allel alignmen he bilaye s would ha e o o m di e en
numbe s o bilaye s a di e en posi ions in he hin ilm in o de
o keep he in e lamella dis ance he same. Such de ec s cos
ene gy and he ilm migh he e o e p e e he pe pendicula
alignmen .
The s uc u es in L
a
-phases wi h a lowe IT 3 con en
(xIT 3 ¼0.65) a e somewha di e en (Fig. 7).
La ge mul ilamella esicles (MLVs) a e now seen in which he
spacing be ween he bilaye s is much la ge han in he mic o-
g aph wi h x¼0.75. The la ge spacings a e p obably he esul
o applying high shea a es o he MLV du ing he blo ing
p ocedu e.
16
C yo-TEM mic og aphs o samples wi h inc easing amoun o
oil a e shown in Fig. 8. The i s wo mic og aphs (Fig. 8A and B)
show simila ne wo k-like s uc u es o he mic og aph o he
L
3
-phase wi hou oil (Fig. 5). I is gene ally assumed ha he
L
3
-phase is a symme ic phase, whe e he inside and ou side
olume o he h ee-dimensional ubula s uc u e is he same. I
is likely ha his symme y is los by he solubilisa ion o oil, and
he mic oemulsion is an asymme ic phase. This can be
concluded om he ab up conduc i i y change ha occu s
Fig. 6 C yo-TEM o samples wi h 15% (w/w) su ac an Ca(DS)
2
/IT 3, x
IT 3 ¼0.75, p epa ed a 40 C. (A) Typical pa e n o L
a
-phase; (B)
L
a
-phase wi h de ec s, shown by whi e a ows.
Fig. 7 C yo-TEM image o sample wi h 15% (w/w) su ac an Ca(DS)
2
/
IT 3, xIT 3 ¼0.65, p epa ed a 40 C. La ge squeezed- oge he mul i-
lamella esicles a e seen.
5370 | So Ma e , 2010, 6, 5367–5374 This jou nal is ªThe Royal Socie y o Chemis y 2010
64

a ound xM
2
¼0.05. Indeed, he obse ed bi-con inuous s uc-
u es by he TEM mic og aphs o samples wi h solubilised oil
look somewha di e en om he mic og aphs o he L
3
-phase
wi hou oil. Howe e , some mic og aphs also show ypical
s uc u es o L
a
-phases o MLV phases. I is likely ha hese
s uc u es esul om e apo a ion o M
2
in he hin ilm. M
2
is an
ex emely ola ile compound. In o de o dec ease he e apo a-
ion as much as possible, he a mosphe e in he p epa a ion
chambe had o be sa u a ed wi h he mic oemulsion solu ion
and he p epa a ion had o be ca ied ou as quickly as possible.
The samples wi h he highes oil con en (Fig. 8C and D) ha e
di e en s uc u es. In bo h samples globula pa icles a e
obse ed ha a e in a ligh e g ey han he backg ound.
Ob iously, he s uc u e has now changed om he
bi-con inuous s uc u e o w/o d ople s. A 50% oil he d ople s
a e densely packed while in he sample wi h 75% oil he d ople
a e mo e dispe sed. The d ople s ha e abou he same size in he
wo samples. The diame e o he d ople s a ies om 20 o 30
nm. Simila globula pa icles al eady ha e been obse ed in he
sys em AOT–n-decane–D
2
O by FF-TEM.
19
The mic og aphs wi h 50% and 75% oil show some in e es ing
de ails ha a e wo h emphasizing. In Fig. 8C some o he small
globula pa icles a e e y da k in compa ison o he ligh g ey
o mos o he o he d ople s. These pa icles make up a ew
pe cen o he o al numbe o pa icles. All hose pa icles a e
c ys alline ice, o med du ing he apid cooling p ocess. The
Fig. 8 C yo-TEM mic og aphs o samples wi h 15% (w/w) su ac an Ca(DS)
2
/IT 3, p epa ed a 40 C: (A) composi ion xIT 3 ¼0.65, xM
2
¼0.05,
sponge-like s uc u e; (B) composi ion xIT 3 ¼0.65, xM
2
¼0.15, sponge-like s uc u e; (C) composi ion xIT 3 ¼0.9, xM
2
¼0.5, densely packed wa e
d ople s and (D) composi ion xIT 3 ¼0.975, xM
2
¼0.75, less densely packed wa e d ople s.
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65
cooling a es achie able by liquid ni ogen, used he e o a oid oil
dissolu ion, a e insu icien o i i y wa e (bu a e su icien o
i i y he oil!). Thus, he small wa e domains eeze in o c ys-
alline hexagonal ice. These nano-c ys als a e andomly o ien ed
wi h espec o he elec on beam, so ha only a ew sa is y
B agg’s law o elec on di ac ion, and hose appea da k. The
ice c ys als ha do no di ac appea ligh g ey. The mic o-
g aphs show ha he ice pa icles could only g ow o he size o
he d ople s, because he d ople s we e no connec ed o
su ounding d ople s.
Mic og aphs, Fig. 8A and B, wi h an oil ac ion o 0.05 and
0.15 seem o ep esen si ua ions ha a e in be ween he L
3
-phase
and he mic oemulsion si ua ion wi h 50% o oil. Fo bo h
samples he c ys alline ice s uc u es a e somewha la ge han
he wa e domains. These esul s a e in ag eemen wi h
conduc i i y measu emen s in he channel, which show a ansi-
ion om he conduc i i y o he L
3
-phase o a lowe
conduc i i y a an oil con en o 5%, and inally o loss o
conduc i i y a 40% oil. The de elopmen o he s uc u es can
he e o e a bes o be ep esen ed by a HIPE like (High In e nal
Phase Emulsion) s uc u e wi h a ying connec i i y be ween he
wa e domains. In some o he mic og aphs one can ac ually
obse e ha some o he d ople s a e de o med o polygonal
s uc u es. Besides he appa en polyhexagon he mic og aph
also shows ha some o he d ople s ha e coalesced wi h he
neighbou ing s uc u es, and ha e o med la ge s uc u es. All
hese de ails demons a e ha he o iginal d ople s a e e y
dynamic species. When he equilib ium condi ions a e changed,
hey can quickly adjus o he new condi ions. In con as o he
mic og aph o he sample wi h 50% oil, he mic og aph wi h 75%
oil shows p ac ically no i egula i ies. Only e y ew d ople s
seem o ha e o med double s, while he la ge majo i y o he
small d ople s is andomly dis ibu ed in he oil ma ix. All in all,
clean mic og aphs o a w/o-mic oemulsion by c yo-TEM a e
as onishing and a e, as i had been o en assumed, ha oil- ich
samples canno be imaged di ec ly,
20
as he oil ge s dissol ed in
he egula ly used c yogen liquid e hane, o he al e na i e
c yogen liquid ni ogen would no p o ide he su icien cooling-
a e o i i y he specimen.
21
C yo-TEM mic og aphs in he lowe channel
The lowe single-phase channel has a la ge slope wi h inc easing
oil concen a ion. In addi ion, he channel is e y na ow. As
a esul o hese wo condi ions i is di icul o ob ain good
mic og aphs om he s uc u es in he channel. As i is ob ious
om he channel, he s uc u es in he channel could change, and
he o iginal s uc u es a e no longe in equilib ium wi h hei
su oundings, when he samples o he channel lose a ew pe cen
o oil by e apo a ion. This is indeed he case, as is demons a ed
in Fig. 9, whe e wo mic og aphs a e shown ha we e ob ained
om a sample wi h xIT 3 ¼0.4 and 15% oil. One mic og aph
(Fig. 9A) shows only small unilamella esicles wi h diame e s
anging om 13 o 40 nm. The o he mic og aph (Fig. 9B) also
shows uni- and mul ilamella esicles wi h in e lamella spacings
ha a e consis en wi h he su ac an concen a ion o 15%.
In addi ion, bo h mic og aphs show long lines ha sepa a e o
su ound la ge domains o di e en shades. Those ep esen an
encapsula ion o small esicles by la ge ones.
Model o he calcula ion o he mic oemulsion d ople size
Dimensions o he wa e o oil d ople s in he mic oemulsions
can easily be calcula ed wi h he co e–shell model and wi h he
help o he oil–su ac an o wa e –su ac an a io.
Wi h he olume o he co e
C¼4
3 3p
and he olume o he shell which is equal o he olume o he
su ac an ,
S
¼4p
2
d
one ob ains he simple equa ion
Fig. 9 C yo-TEM mic og aphs o sample wi h 15% (w/w) su ac an
Ca(DS)
2
/IT 3, xIT 3 ¼0.4, xM
2
¼0.15, p epa ed a 40 C. (A) Small
unilamella esicles wi h diame e om 13 o 40 nm. (B) Small uni-
lamella esicles and mul ilamella esicles.
5372 | So Ma e , 2010, 6, 5367–5374 This jou nal is ªThe Royal Socie y o Chemis y 2010
66
C
S
¼4p 3
34p 2d¼R
and ¼R3d.
In his equa ion dis he hickness o he su ac an monolaye ,
namely he hickness o he shell. The hickness dcan expe i-
men ally be app ecia ed om he c yo-TEM mic og aphs o he
L
a
-phase o can be es ima ed om he numbe o CH
2
-g oups in
he su ac an molecules. In an exac calcula ion, he di e en
leng hs o he wo su ac an molecules and hei di e en mole
a ios in he uppe and lowe channel ha e o be conside ed.
The assumed d alue, he olume a io o he co e and shell
C
/
S
, he calcula ed diame e s D
cal
¼2 +2do he d ople s and
he expe imen ally de e mined diame e s D
exp
om he c yo-
TEM images a e gi en in Table 1.
Fo he calcula ion o
C
/
S
, he densi y o he su ac an
mix u e was es ima ed o 1 g cm
3
, o he olume o he oil, we
used he densi y o 0.76 g cm
3
o M
2
.
The ag eemen be ween he calcula ed and expe imen al
de e mined diame e s in he lowe channel a e no e y good.
The mic og aph o he mic oemulsion wi h xM
2
¼0.15 om he
lowe channel shows a la ge a ie y o small esicles wi h
diame e s om 13–40 nm, which does no ag ee wi h he model.
In con as o he lowe channel, he measu ed size o he
d ople s om he uppe channel di e s only li le om he
calcula ed alues. Al hough he d ople s show a ce ain a ie y in
size dis ibu ion, he expe imen al de e mined diame e s a e in
good ag eemen wi h he co e–shell model, conside ing he
di icul condi ions o sample p epa a ion as he high ola ili y
o he silicone oil and he high empe a u e.
Conclusion
The nanos uc u es in he wo iso opic channels o a mic o-
emulsion o he silicone oil hexame hyldisiloxane (M
2
) and
a su ac an mix u e o he anionic su ac an calcium dodecyl
sul a e Ca(DS
2
) and he nonionic su ac an iso- idecyl- ie-
hyleneglycole he (IT 3) ha e been de e mined by c yo-TEM.
Con a y o mic oemulsions wi h a pu e nonionic su ac an , he
channels can be o med in his sys em a cons an empe a u e by
adjus ing he mass ac ion o he wo su ac an s. The channel
wi h he highe mass ac ion o nonionic su ac an begins wi h
he L
3
-phase on he wa e side, and uns wi h a shallow slope o
he oil side, when he mass ac ion is plo ed agains he oil
con en . Conduc i i y esul s and c yo-TEM mic og aphs indi-
ca e ha bicon inuous s uc u es exis in his channel om he
wa e side o a mic oemulsion wi h a 65/35 wa e oil a io. The
mic og aphs show ha he s uc u e in he bi-con inuous egion
changes om an L
3
- ype s uc u e o a HIPE- ype s uc u e.
Wa e d ople s in he oil ma ix exis om he middle o he
phase diag am un il he oil side. This di e s om he nano-
s uc u es o mic oemulsions wi h nonionic su ac an s, whe e
elemen s o bicon inuous mic os uc u es, e en a high oil
con en s, a e epo ed.
22
The sizes o he w/o-d ople s in he
uppe channel a e consis en wi h simple geome ical conside -
a ions. They inc ease, as expec ed, wi h an inc easing mass
ac ion o wa e .
The lowe channel begins on he wa e side wi h an L
1
-phase
and eaches wi h inc easing oil concen a ion o he middle o he
phase diag am. The channel con ains o/w d ople s in a con in-
uous wa e ma ix. No connec ion was ound be ween he wo
channels. Because o he high ola ili y o he oil, he d ople s in
his channel we e di icul o image wi h he c yo-TEM me hod.
Small esicles we e ob ained in many p epa a ions, ins ead o he
d ople s. The esicles we e ob iously o med in he hin c yo- ilm
in he ime be ween o ming and ixa ion by empe a u e
quenching. The e o e, we a e ying o imp o e he design o ou
CEVS o allow us wo k wi h mo e highly ola ile sol en s such as
M
2
, wi h e en smalle concen a ion changes. We a e also
looking o a mic oemulsion sys em based on a lowe - ola ili y
oil, ha gi es a simila phase diag am.
Expe imen al
Ma e ials
The nonionic su ac an iso- idecyl- ie hyleneglycole he ,
abb e ia ed as IT 3, was ob ained om Sasol, Co., Hambu g
(Ma lipal O13/30). Sodium dodecyl sul a e (SDS, c ys . esea ch
g ade) was pu chased om he Se a Co., Heidelbe g. MgCl
2

6H
2
O and CaCl
2
2H
2
O we e pu chased om he G €
ussing
Co., Filsum. The silicone oil hexame hyldisiloxane, abb e ia ed
M
2
, was pu chased om he Wacke Co., M€
unchen, n-decane
was ob ained om he Me ck Co., Da ms ad .
P epa a ion o Ca(DS)
2
and Mg(DS)
2
Fo he p epa a ion o Ca(DS)
2
and Mg(DS)
2
, 400 mM
SDS-solu ion we e mixed wi h ei he 200 mM CaCl
2
o MgCl
2
solu ion unde s i ing. The bi alen coun e ions Ca
2+
and Mg
2+
bind s onge o he dodecyl sul a e han he sodium-ion, leading
o a p ecipi a ion o Ca(DS)
2
in solu ion below i s K a -
empe a u e o 50 C, and Mg(DS)
2
below i s K a - empe a u e
o 25 C. The solu ions we e hea ed up o 60 C o he solu ion
wi h CaCl
2
, o wa med up abo e 25 C o he solu ion wi h
MgCl
2
o ob ain a clea solu ion, and hen cooled down o 20 C.
A e p ecipi a ion, Ca(DS)
2
and Mg(DS)
2
we e washed se e al
imes wi h de-ionised wa e o emo e excess sal . The pu i y o
he il e ed su ac an hus could be checked by measu ing he
conduc i i y o i s low h ough. The washed Ca(DS)
2
and
Mg(DS)
2
we e d ied o se e al days in a cabine d ye a 50 C,
and la e used wi hou u he pu i ica ion.
Table 1 O e iew o he calcula ed diame e s D
cal
and expe imen ally
de e mined diame e s D
exp
o he mic oemulsion d ople s om he lowe
and uppe single-phase channel
Size o d ople s in lowe channel
xM
2
d/nm
C
/
S
/nm D
cal
/nm D
exp
/nm
0.15 1.5 1.12 5 13 13–40
Size o d ople s in uppe channel
xM
2
xH
2
Od/nm
C
/
S
/nm D
cal
/nm D
exp
/nm
0.5 0.5 1.5 2.83 12.8 29 36 6
0.75 0.25 1.5 1.42 6.4 16 25 6
This jou nal is ªThe Royal Socie y o Chemis y 2010 So Ma e , 2010, 6, 5367–5374 | 5373
67
P epa a ion o samples
All samples we e p epa ed by weighing in di ec ly he compo-
nen s in es ubes, i s su ac an and co-su ac an , H
2
O, and,
as las componen , M
2
, due o i s high ola ili y. The es ubes
we e sealed wi h Te lon ape, empe ed a 40 C in a wa e ba h,
and o exed se e al imes ho oughly. All samples we e incu-
ba ed a leas 3 days a 40 C be o e being in es iga ed o hei
phase beha iou . Fo he phase diag am, he samples below xIT
3 0.3 had o be p epa ed wi h Mg(DS)
2
ins ead o Ca(DS)
2
o
a oid p oblems wi h p ecipi a ion o Ca(DS)
2
. In gene al,
a phase diag am was scanned wi h a esolu ion o 5% in he
composi ion o he mass ac ion o IT 3 and M
2
. Fine s eps
we e in es iga ed in he beginning o he uppe single-phase
channel, and in be ween he wo single-phase channels o ind
a possible connec ion o bo h channels. The mul iphase samples
we e iewed and imaged wi hou and in be ween c ossed pola -
ise s, o isualise he bi e ingence o lamella egions.
C yo-T ansmission Elec on Mic oscopy (C yo-TEM)
The specimens o c yo-TEM we e p epa ed in a con olled
en i onmen i i ica ion sys em (CEVS) and plunged in o liquid
e hane a i s eezing poin .
23
Fo oil con inuous samples, he
specimens we e plunged in o liquid ni ogen in o de o o e -
come p oblems wi h sol en dissolu ion.
24
The CEVS was kep a
40 C and he a mosphe e ei he sa u a ed wi h H
2
O o he
samples wi hou oil, o di ec ly wi h he in es iga ed mic o-
emulsion solu ion o samples con aining oil. Due o high ola-
ili y o he silicone oil, he specimens we e p epa ed as quickly as
possible. Specimens, kep below 178 C, we e examined in an
FEI TI2 G
2
ansmission elec on mic oscope, ope a ed a 120
kV, using a Ga an 626 c yoholde sys em. Images we e eco ded
digi ally in he minimal elec on dose mode by a Ga an US1000
high- esolu ion CCD came a, wi h he Digi al Mic og aph
so wa e package.
Acknowledgemen s
We wan o hank he Russell Be ie Nano echnology Ins i u e,
Technion (RBNI), o p o iding us he oppo uni y o in es i-
ga e ou specimen by elec on mic oscopy. Fo he excellen
echnical assis ance, we especially hank Judi h Schmid and D
Ellina Kesselman, and all membe s o he Lab o he Depa men
o Chemical Enginee ing, Technion-Is ael Ins i u e o Tech-
nology, Hai a 32000, Is ael.
No es and e e ences
1 R. S ey, Cu . Opin. Colloid In e ace Sci., 1996, 1, 402–410.
2 S. J. Chen, D. Fennell E ans and B. W. Ninham, J. Phys. Chem.,
1984, 88, 1631.
3 S. H. Chen and S. L. Chang, J. Phys. Chem., 1991, 95, 7427–7432.
4 C. Ma hew, Z. Saidi, J. Pey elasse and C. Boned, Phys. Re . A, 1991,
43(2), 872–882.
5 J. Be genhol z, A. A. Romagnoli and N. J. Wagne , Langmui , 1995,
11(5), 1559–1570.
6 T. So mann and C. S uben auch, Phase Beha io , In e acial
Tension, and Mic os uc u e o Mic oemulsions, in Mic oemulsions:
Backg ound, New Concep s, Applica ions, Pe spec i es, ed. C.
S uben auch, John Wiley & Sons, Ox o d, 2009, ch. 1.
7 T. So mann and R. S ey, Mic oemulsions, in So Colloids V—
Fundamen als in In e ace and Colloid Science, ed. J. Lyklema,
Else ie , Ams e dam, 2005, ch. 5.
8 F. Lich e eld, T. Schmeling and R. S ey, J. Phys. Chem., 1986, 90,
5762–5766.
9 T. So mann and R. S ey, J. Chem. Phys., 1997, 106, 8606–8615.
10 C. S uben auch and T. So mann, Mic oemulsions s abilized by
Suga Su ac an s, in Suga -Based Su ac an s: Fundamen als and
Applica ions, ed. C. C. Ruiz, Taylo & F ancis, CRC P ess, Boca
Ra on, 2009, ch. 12.
11 IT 3 is comme cially a ailable unde he name ‘‘Ma lipal O13/30’’
om Sasol Ge many GmbH, Auckelmannspla z 1, 20537 Hambu g,
Ge many.
12 L. Wol , H. Ho mann, K. Wa anabe and T. Okamo o, PCCP,
submi ed.
13 M. Kahlwei , e al., J. Colloid In e ace Sci., 1987, 118, 436–453.
14 R. S ey, Colloid Polym. Sci., 1994, 272, 1005–1019.
15 M. Kahlwei , B. Faulhabe and G. Busse, Langmui , 1994, 10, 2528–
2532.
16 D. Danino, D. Weihs, R. Zana, G. O €
add, G. Lindblom, M. Abe and
Y. Talmon, J. Colloid In e ace Sci., 2003, 259, 382–390.
17 H. Ho mann, C. Thunig, U. Munke , H. W. Meye and W. Rich e ,
Langmui , 1992, 8, 2629–2638.
18 R. S ey, W. Jahn, G. Po e and P. Basse eau, Langmui , 1990, 6,
1635–1639.
19 W. Jahn and R. S ey, J. Phys. Chem., 1988, 92, 2294–2301.
20 L. Belkou a, C. S uben auch and R. S ey, Langmui , 2004, 20,4391–
4399.
21 V. Aga wal, M. Singh, G. McPhe son, V. John and A. Bose,
Langmui , 2004, 20, 11–15.
22 S. Bu aue , L. Belkou a, C. S uben auch and R. S ey, Colloids Su .,
A, 2003, 228, 159–170.
23 D. Danino, A. Be nheim-G oswasse and Y. Talmon, Colloids Su .,
A, 2001, 183, 113–122.
24 Y. Talmon, D. Danino, J. Sa aya olu and R. Gup a, J. Colloid
In e ace Sci., 2002, 249, 180–186.
5374 | So Ma e , 2010, 6, 5367–5374 This jou nal is ªThe Royal Socie y o Chemis y 2010
68
Dynamic P ope ies o Mic oemulsions in he Single-Phase channels
69
5.1.3. Dynamic P ope ies o Mic oemulsions in he Single-Phase channels
Lukas Wol *, Heinz Ho mann, Wal e Rich e , Takashi Teshigawa a and Toh u Okamo o.
*co esponding au ho
Published in Jou nal o Physical Chemis y B, 2011, 115(38), 11081-11091.
DOI: 10.1021/jp2036789.

Published: Augus 15, 2011
2011 Ame ican Chemical Socie y 11081 dx.doi.o g/10.1021/jp2036789 |J. Phys. Chem. B 2011, 115, 11081–11091
ARTICLE
pubs.acs.o g/JPCB
Dynamic P ope ies o Mic oemulsions in he Single-Phase Channels
Lukas Wol ,*
,†
Heinz Hoffmann,
†
Wal e Rich e ,
‡
Takashi Teshigawa a,
§
and Toh u Okamo o
§
†
Uni e si y o Bay eu h, BZKG and BayColl, Go lieb-Keim-S . 60, 95448 Bay eu h, Ge many
‡
F ied ich-Schille -Uni e si y, Cen e o Elec on Mic oscopy, Ziegelm€uhlenweg 1, 07743 Jena, Ge many
§
Shiseido Resea ch Cen e , 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama, Japan 224-8558
b
SSuppo ing In o ma ion
’INTRODUCTION
Mic oemulsions a e he modynamically s able phases om
oil, wa e , and su ac an s.
1
The phases con ain well-defined
s uc u es, such as oil d ople s in a con inuous wa e phase, wa e
d ople s in a con inuous oil phase, and bicon inuous s uc u es.
The de ailed s uc u es depend on he composi ion o he sys em
in he e na y phase diag am. Usually, he s uc u es change wi h
a change in he composi ion o he samples. Fo many yea s,
mic oemulsions wi h ionic su ac an s we e in he ocus o
in e es .
2
Mo e ecen ly, mic oemulsions wi h nonionic su ac-
an s ha e become he cen e o in e es .
3
As a consequence, we
now ha e a good unde s anding o mic oemulsions. I is known,
o example, how he phases can be op imized o as li le
su ac an as possible and how he su ac an can be op imized
o a gi en oil. O undamen al impo ance o he unde s anding
o he sys ems is he alue o he in e acial ension o a micella
solu ion agains an oil phase.
4
Fo a high solubiliza ion o an oil in
a micella solu ion, he in e acial ension has o be minimized.
5
One o he mos ascina ing ea u es o nonionic mic oemulsions
is iso opic single-phase channels ha pass om he aqueous
micella phase con inuously o he oil phase o cons an
su ac an concen a ion.
6
Because o SANS and SAXS, we ha e
a good unde s anding o he s uc u es in hese channels. Many
sys ems ha e been in es iga ed ha ha e wo channels om
he wa e o he oil side, one a lowe empe a u e and one a a
highe empe a u e, and a single channel in he middle o he
phase diag am ha is connec ed wi h he wo channels a bo h
sides.
7
Today, he e is a good heo e ical unde s anding o he
s uc u es in he iso opic channels and abou he he mo-
dynamics o mic oemulsions wi h nonionic su ac an . Howe e ,
e y ew in es iga ions ha e been ca ied ou on he dynamic
beha io o he mic oemulsions, and no sys ema ic in es iga ion
has so a been made in a channel om he wa e side o he
oil side.
In his in es iga ion, we he e o e will s udy he dynamic
p ope ies o mic oemulsions in he single-phase channels by
heology and he elec ic bi e ingence me hod. The measu e-
men s we e ca ied ou on a sys em wi h an anionic/nonionic
su ac an mix u e ha was simila o one ha was p e iously
s udied and om which we knew he posi ion o he single phase
channels.
8
Recei ed: Ap il 20, 2011
Re ised: Augus 15, 2011
ABSTRACT: We ha e s udied he dynamic and heological
p ope ies in he single-phase channels o a mic oemulsion
sys em wi h a mixed anionic/nonionic su ac an sys em and
decane om he aqueous o he oil phase. One iso opic
channel, called he “uppe ”channel, begins a he L
3
phase
(sponge-like phase) o he bina y su ac an mix u e on he
wa e side and passes wi h a shallow minimum o he su ac an
composi ion o he oil side. The o he “lowe ”single-phase
channel begins a he micella L
1
phase and ends in he middle
o he phase diag am. Bo h iso opic channels a e sepa a ed by a
huge aniso opic single phase L
α
channel ha eaches om he wa e side o 90% o oil in he sol en mix u e. The s uc u al
elaxa ion ime o he iscous fluids could be measu ed wi h elec ic bi e ingence (EB) measu emen s, whe e a signal is caused by
he de o ma ion o he in e nal nanos uc u e o he fluids by an elec ic field. Fo he L
3
phase, he EB signal can be fi ed wi h a
single ime cons an . Wi h inc easing oil in he uppe channel, he main s uc u al elaxa ion ime passes o e a maximum and
co ela es wi h he iscosi y. Ob iously, his ime cons an con ols he iscosi y o he fluid (η
o
=G03τ). I is ema kable ha he
longes s uc u al elaxa ion ime inc eases h ee decades, and he iscosi y inc eases wo decades when 10% o oil is solubilized in o
he L
3
phase. Conduc i i y da a imply ha he fluid in he uppe channel has a bicon inuous s uc u e om he L
3
phase o he
mic oemulsion wi h only 10% oil. In his oil ange, he conduc i i y dec eases h ee decades, and he elec ic bi e ingence signals a e
complica ed because o a supe posi ion o up o h ee p ocesses. Fo highe oil a ios, he s uc u e ob iously changes o a HIPE
(high in e nal phase emulsion) s uc u e wi h wa e d ople s in he oil ma ix.
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11082 dx.doi.o g/10.1021/jp2036789 |J. Phys. Chem. B 2011, 115, 11081–11091
The Jou nal o Physical Chemis y B ARTICLE
’EXPERIMENTAL SECTION
Ma e ials. The nonionic su ac an iso- idecyl- ie hylengly-
cole he , abb e ia ed as IT 3, was ob ained om he Sasol
Company (Hambu g, Ge many) (“Ma lipal O13/30”). This
compound has a polydispe se dis ibu ion o EO g oups
wi h an a e age o h ee EO uni s. Sodium dodecyl sul a e (SDS,
c ys . esea ch g ade) was pu chased om he Se a Company
(Heidelbe g, Ge many). MgCl
2
36H
2
O was pu chased om he
G €ussing Company (Filsum, Ge many). N-Decane (analy ical
g ade) was ob ained om he Me ck Company (Da ms ad ,
Ge many).
P epa a ion o Mg(DS)
2
.Fo he p epa a ion o Mg(DS)
2
,
400 mM SDS solu ion was mixed wi h 200 mM MgCl
2
solu ion
unde s i ing. The bi alen coun e ion Mg
2+
binds s onge o
he dodecyl sul a e han he sodium ion, leading o a p ecipi a ion
o Mg(DS)
2
in solu ion below i s K a empe a u e a ound
25 °C. The solu ion was hea ed abo e 25 °C o ob ain a clea
solu ion and hen cooled o 20 °C. A e p ecipi a ion o e nigh ,
Mg(DS)
2
was il e ed and washed se e al imes wi h deionized
wa e o emo e excess sal . The pu i y o he su ac an hus
could be checked by measu ing he conduc i i y o he low
h ough o he il e ed Mg(DS)
2
. The washed Mg(DS)
2
was
eeze-d ied wi h he eeze-d ying de ice Alpha 1-4, Ch is
Company (Os e ode, Ge many), and used wi hou u he
pu i ica ion.
P epa a ion o Samples. All samples we e p epa ed by
weighing he componen s di ec ly in es ubes on an analy ical
balance. The es ubes we e sealed wi h Te lon ape, empe ed a
25 °C in a wa e ba h, and o exed se e al imes ho oughly. All
samples we e incuba ed a leas 3 days a 25 °C be o e being
in es iga ed o hei phase beha io . In gene al, a phase diag am
was scanned wi h a esolu ion o 5% in he composi ion o he
mass ac ion o IT 3 and decane. Fine s eps we e in es iga ed in
he beginning o he na ow uppe single-phase channel. The
mul iphase samples we e iewed and imaged wi hou and in
be ween c ossed pola ize s o isualize he bi e ingence o lamella
egions.
F eeze-F ac u e T ansmission Elec on Mic oscopy (FF-TEM).
The mic oemulsions, p epa ed in p esence o 20% (w/w)
glyce in in he aqueous phase we e s o ed a oom empe a u e
(25 °C) and quick- ozen om RT using he sandwich echnique.
A small amoun o he samples was sandwiched be ween wo
coppe p o iles (BAL-TEC/Balze s, Liech ens ein) as used o
he double- eplica echnique and ozen by plunging hese
sandwiches immedia ely in o a lique ied e hanep opane mix-
u e ( / 1/1) cooled in liquid ni ogen. F ac u ing and eplica-
ion we e pe o med a 150 °C in a BAF 400T eeze- ac u e
de ice (BAL-TEC/Balze s, Liech ens ein) equipped wi h elec-
on guns and a ilm shee hickness moni o . Fo eplica ion, a
i s , P (C) was e apo a ed unde an angle o 35°( hickness:
2 nm), ollowed by C unde 90°angle ( hickness 20 nm). The
eplicas we e placed on elec on mic oscopic coppe g ids (Mesh
400), cleaned by chlo o o mme hanol mix u e ( / 2/1), and
examined in an EM 900 elec on mic oscope (Zeiss, Obe ko-
chen, Ge many).
Conduc i i y and Rheology Measu emen s. Fo conduc-
i i y measu emen s, we used he mic op ocesso conduc i i y
me e LF3000 om he WTW Company (Weilheim, Ge many).
The heology was measu ed wi h he conepla e heome e
RheoS ess 600 om he Haake The mo Scien i ic Company
(Ka ls uhe, Ge many). All samples we e in es iga ed a 25 °C.
Elec ic Bi e ingence Measu emen s. The elec ic bi e in-
gence de ice is a sel -made de ice wi h a 632.8 nm HeNe lase ,
c ossed pola ize s, ape u e pla es, a Ke cell wi h empe a u e
con ol, and a pho omul iplie . Fo he gene a ion o an elec ic
pulse, he e was used he Cobe “high powe pulse gene a o ”
model 606. The signal o he pho omul iplie was eco ded wi h
he Vol c a DSO-2090 USB-oszillog aph. Da a we e p ocessed
and e alua ed wi h he compu e so wa e “O igin”.
SANS Measu emen s. Fo SANS measu emen s, samples
we e p epa ed wi h D
2
O ins ead o H
2
O. By eplacing H
2
Oby
D
2
O, he phases in he single-phase channels a e sligh ly shi ed.
To ob ain anspa en iso opic phases, we had o adjus he
su ac an composi ion by inc easing he mass ac ion o IT 3 by
∼2%. SANS da a we e ob ained wi h he SANS de ice D11 a he
Ins i ue Lau e-Lange in in G enoble, F ance. Samples we e illed
in 1 mm qua z cu e e (Helma), and empe a u e was se o
25 °C.
E alua ion o da a (backg ound de ec ion, sub ac ion o
signal in ensi y, scaling o da a) was pe o med wi h s anda d
compu e so wa e.
’RESULTS AND DISCUSSION
Phase Diag am Mg(DS)
2
/IT 3H
2
O/n-Decane. On mic o-
emulsion sys ems wi h a single nonionic su ac an , i is no
possible o pass om a single aqueous phase o a single oil phase
a cons an empe a u e. The in e acial ension o nonionic
su ac an s changes wi h empe a u e, and hus he single-phase
egions o mic oemulsions a e empe a u e-dependen . The
amphiphilic p ope ies o su ac an s can also be changed by
adding a cosu ac an o he su ac an solu ion. In he p esen
in es iga ion, we he e o e chose a bina y mix u e o a hyd o-
philic su ac an wi h a lipophilic su ac an . Fo he ionic
su ac an , we chose he Mg
2
sal o SDS. Mg(DS)
2
is mo e
lipophilic han SDS, educes he su ace ension mo e e ec i ely,
and is known o o m liquid c ys alline L
α
phases when mixed
wi h sui ed cosu ac an s.
8
As lipophilic cosu ac an , we used
iso- idecyl- ie hylenglycole he (abb e ia ion IT 3, = C
13
E
3
).
By changing he mass ac ion o he wo molecules in he
su ac an solu ion, i u ned ou o be possible o pass om a
micella L
1
phase wi h only Mg(DS)
2
o e lamella L
α
and an L
3
phases (sponge-like phase) wi h he su ac an mix u es o an L
1
/
L
2
(L
2
= in e se micella phase) wo phase si ua ion o he
solu ion wi h pu e IT 3. The phase sequence o he bina y
su ac an mix u e is shown in Figu e SI1 o he Suppo ing
In o ma ion, and de ailed heological in es iga ions can be ound
in Figu e SI2 o he Suppo ing In o ma ion. Some nonionic
su ac an s show he same sequence o phases wi h inc easing
empe a u e.
The plo o he su ac an mix u e agains he mass ac ion x
o he oil decane in he sol en mix u e be ween 0 and 1 is shown
in Figu e 1. The o al su ac an concen a ion was kep cons an
a 15% (w/w), he empe a u e was kep a 25 °C, and samples
we e p epa ed wi h 20% glyce ine in H
2
O o possible FF-TEM
in es iga ions o p e en eezing a i ac s.
The phase diag am con ains wo iso opic channels, a lowe
one and an uppe one. The uppe one begins on he su ac an
axis a he egion o he L
3
phase. Wi h inc easing oil, he channel
fi s shi s o a lowe IT 3 a io and hen again o a highe IT 3/
Mg(DS)
2
a io o highe oil a ios. I ends on he oil side a 80%
decane and pu e IT 3 as su ac an . The lowe channel begins a
71
11083 dx.doi.o g/10.1021/jp2036789 |J. Phys. Chem. B 2011, 115, 11081–11091
The Jou nal o Physical Chemis y B ARTICLE
he L
1
egion and ends in he middle o he phase diag am a an
IT 3 a io o 0.57.
Bo h channels a e sepa a ed by a huge single-phase bi e in-
gen L
α
egion ha ex ends om 0 o 90% decane wi h sligh ly
inc easing mass ac ion o IT 3. All samples in he L
α
channel
beha e like gels. Howe e , he s o age modulus G0is dec easing
cons an ly wi h inc easing oil con en , indica ing ha he gels
become so e . Pic u es o he L
α
phases be ween c ossed
pola ize s a diffe en empe a u es and de ailed heology da a
can be ound online in Figu e SI3 o he Suppo ing In o ma ion.
A significan ea u e o he L
α
channel is i s high- empe a u e
s abili y. Samples be ween xdecane = 0 o 0.9 a e s able a leas
be ween 10 and 40 °C, and samples wi h xdecane 0 o 0.4 a e
e en s able a leas up o 60 °C. Al hough he L
α
channel is qui e
na ow, i s high- empe a u e s abili y is amazing. This ea u e is
ob ious due o he su ac an mix u e, whe e he hyd ophilic
lipophilic balance is de e mined mo e by he mass ac ion o
he cosu ac an han by he empe a u e. L
α
phases wi h oil
and a single nonionic su ac an o he ype C
i
E
j
a e no so
s able.
32
The mic oemulsions in he lowe single phase channel a e
anspa en phases ha show no flow bi e ingence unde shea .
The samples in he uppe phase channel ha e somewha diffe en
p ope ies. Whe eas he L
3
phase wi hou decane is comple ely
anspa en , he samples wi h decane look somewha bluish and
hei sca e ing in ensi y is mos in ensi e a ound xdecane 0.03
and 0.1. Fo highe oil con en , he sca e ing in ensi y is
dec easing again. Pic u es o samples om he lowe and uppe
single phase channel a e shown in Figu e SI4 o he Suppo ing
In o ma ion. The diffe en mac oscopic p ope ies in he uppe
and lowe phase channels o he same amoun o oil a e al eady
an indica ion ha he s uc u es in he wo single-phase channels
a e diffe en . In many p e ious publica ions o mic oemulsions, i
was shown ha he micella s uc u es in a single-phase channel
a ied om o/w d ople s o bicon inuous s uc u es o w/o
s uc u es.
9
The ollowing chap e s will show, ha he si ua ion in
he p esen sys em mus be diffe en and mo e complica ed. I
should, howe e , be clea ha he si ua ion in nonionic and in
somewha ionically cha ged sys ems may be somewha diffe en .
Ou in es iga ed sys em is he fi s sys em wi h an ionic
su ac an o which he ionic cha ge was no shielded by excess
sal ha o ms an iso opic channel om he wa e side o he
oil side.
Conduc i i y in he Single-Phase Channels. The plo o he
conduc i i y in he uppe and lowe single-phase channels
agains he mass ac ion o decane in he sol en mix u e is
shown in Figu e 2.
In he uppe channel, he conduc i i y fi s inc eases sligh ly
om ∼1000 μS/cm o he sample wi hou decane o 1160 μS/
cm o he sample wi h 1% decane. The eason o his lies in he
change o he composi ion o he su ac an mix u e. In he ange
om 1 o 10% decane, he conduc i i y dec eases ab up ly h ee
o de s o magni ude o 1 μS/cm e en hough he ac ion o he
anionic Mg(DS)
2
is inc easing. Fo highe mass ac ions o
decane, he conduc i i y alues dec ease con inuously o low
alues as, o example, 0.03 μS/cm o he sample wi h a wa e /
oil a io o 1/1 (w/w). The conduc i i ies hus indica e a
d ama ic change in he nanos uc u e o he uppe channel wi h
solubiliza ion o small amoun s o oil in o he L
3
phase. The
ab up collapse o he conduc i i y indica es ha he sys em
Figu e 2. Plo o conduc i i y ( ed do s) and IT 3 con en (g ay
iangles) agains mass ac ion o decane in sol en mix u e. (a)
Conduc i i y da a o he uppe single phase channel. (b) Conduc i i y
da a o he lowe single phase channel.
Figu e 1. Phase diag am o sys em Mg(DS)
2
/IT 3H
2
O/decane a
15% (w/w) su ac an and 25 °C, 20% glyce in in H
2
OIT 3 = mass
ac ion o IT 3 in he su ac an mix u e, xdecane = mass ac ion o
decane in he sol en mix u e. “ME”indica es iso opic mic oemulsion
a ea, and L
α
indica es a ea o aniso opic lamella channel.
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11084 dx.doi.o g/10.1021/jp2036789 |J. Phys. Chem. B 2011, 115, 11081–11091
The Jou nal o Physical Chemis y B ARTICLE
changes om a bicon inuous s uc u e o a w/o s uc u e (wa e -
in-oil). Conduc i i ies in he iso opic channels o mic oemul-
sions om nonionic su ac an s ha e been epo ed in he li e a u e.
10
In such sys ems, he conduc i i y in he uppe channel
dec eases con inuously wi h inc easing oil con en . These mea-
su emen s ha e helped o es ablish he iew ha we ha e oday
om he s uc u es in he uppe channel. Wi h inc easing oil
con en , he bicon inuous L
3
phase swells wi h he solubilized oil
be ween he bilaye s and is finally ans o med a high oil con en
o a w/o sys em. Wi h equal amoun o oil and wa e , SAXS da a
and conduc i i ies show ha his phase is s ill a bicon inuous
phase.
11
Ou conduc i i y da a unambiguously show ha he
s uc u es in he uppe channel o he in es iga ed sys em a e
diffe en om he s uc u es o known sys ems wi h nonionic
su ac an s. We find a a he ab up ansi ion om he bicon in-
uous L
3
s uc u e o a w/o s uc u e wi h only 10% o oil in he
sol en mix u e.
The conduc i i y da a o he lowe channel indica e ha he
nanos uc u e in he lowe channel does no change much wi h
inc easing oil in con as wi h he nanos uc u e in he uppe
channel. A he wa e co ne , he conduc i i y in he lowe
channel wi h 2900 μS/cm is much highe han he conduc i i y
o he L
3
phase o he uppe channel wi h 1000 μS/cm. The
eason o his is ha he Mg(DS)
2
concen a ion is much
highe in he lowe channel. Wi h inc easing oil con en , he
conduc i i ies dec ease sligh ly o 1500 μS/cm a he middle o
he phase diag am, which is whe e he channel ends. The eason
o he dec ease is mainly he dec easing mass ac ion o
Mg(DS)
2
. Ob iously, he lowe channel consis s o a con inuous
wa e phase in which oil d ople s a e dispe sed (o/w s uc u e).
As al eady men ioned, he lowe and uppe single-phase
channels a e no connec ed o each o he in con as wi h he
classical mic oemulsion sys ems wi h single nonionic su ac an
and hyd oca bons. In he p esen sys em, bo h channels a e
sepa a ed by a la ge single aniso opic L
α
channel.
A plo o he conduc i i y in he L
α
channel can be ound in
Figu e SI4 o he Suppo ing In o ma ion. The conduc i i y on
he wa e -side is ∼400 μS/cm and dec eases wi h inc easing oil
con en and inc easing xIT 3 cons an ly o a alue o 40 μS/cm
a he L
α
phase wi h 90% decane. I is no ewo hy ha he sample
wi hou decane a he wa e side has a lowe conduc i i y han he
L
3
phase despi e he ac ha i con ains ∼60% mo e anionic
Mg(DS)
2
and also a much lowe conduc i i y han he mic o-
emulsion om he lowe single-phase channel wi h he same xIT
3 alue o 0.5. This al eady indica es ha he s uc u e consis s o
densely packed mul ilamella esicles, whe e he conduc i i y is
low due o he limi ed mo emen o he ions.
12
FF-TEM Mic og aphs in he Uppe Channel. An FF-TEM
mic og aph o he L
3
phase wi hou oil is shown in Figu e 3a. In
his echnique, he eplica o a ac u ed plane ac oss he sample is
Figu e 3. FF-TEM mic og aphs wi h 15% (w/w) su ac an Mg(DS)
2
/IT 3, 20% glyce ine in H
2
O, p epa ed a 25 °C; scale ba = 200 nm. (a) L
3
phase
wi hou oil a xIT 3 = 0.79, (b) mic oemulsion o uppe channel wi h xIT 3 0.67, xdecane 0.2, (c) mic oemulsion o lowe channel wi h xIT 3 = 0.35, x
decane = 0.1, o/w-s uc u e, d ople size ∼7 nm, and (d) mic oemulsion o lowe channel wi h xIT 3 = 0.45, xdecane = 0.2, d ople size ∼14 nm.
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11091 dx.doi.o g/10.1021/jp2036789 |J. Phys. Chem. B 2011, 115, 11081–11091
The Jou nal o Physical Chemis y B ARTICLE
(16) Scho , W.; Hoffmann, H. Physics o Amphiphiles: Micelles,
Vesicles and Mic oemulsions: P oceedings o he In e na ional School o
Physics; Degio gio, V., Co i, M., Eds.; No h-Holland: Ams e dam,
1985; pp 160180.
(17) K €ame , U.; Hoffmann, H. Mac omolecules 1991,24, 256–263.
(18) Hoffmann, H.; K €ame , U.; Thu n, H. J. Phys. Chem. 1990,
94, 2027–2033.
(19) S ellwagen, N. C. Biopolyme s 1991,31, 1651–1667.
(20) Mille , C. A.; G adzielski, M.; Hoffmann, H.; K €ame , U.;
Thunig, C. P og. Colloid Polym. Sci. 1991,84, 243.
(21) Ca es, M. E.; Roux, D. J. Phys.: Condens. Ma e 1990,
2, 339–346.
(22) S ey, R.; Jahn, W.; Skou i, M.; Po e, G.; Ma ignan, J.; Olsson,
U. In S uc u e and Dynamics o S ongly In e ac ing Colloids and
Sup amolecula Agg ega es in Solu ion; Chen, S. H., Huang, J. S., Ta aglia,
P., Eds.; Kluwe Academic: Bos on, 1992; pp 351363.
(23) Po e, G.; Appel, J.; Basse eau, P.; Ma ignan, M.; Skou i, M.;
Billa d, J.; Delsan i, M.; Candau, S. J.; Jahn, J.; Nab e, P. P og. Colloid
Polym. Sci. 1991,84, 264.
(24) Kahlwei , M.; S ey, R.; Haase, D.; Kunieda, H.; Schmeling, T.;
Faulhabe , B.; Bo ko ec, M.; Eicke, H. F.; Busse, G.; Egge s, F.; Funck,
T.; Richmann, H.; Magid, L.; Sode man, O.; S ilbs, P.; Winkle , J.;
Di ich, A.; Jahn, W. J. Colloid In e ace Sci. 1987,118, 445.
(25) Mille , C.; G adzielski, M.; Hoffmann, H.; K €ame , U.; Thunig,
C. Colloid Polym. Sci. 1990,268, 1066–1072.
(26) K €ame , U.; Hoffmann, H. In The S uc u e, Dynamics, and
Equilib ium P ope ies o Colloidal Sys ems; Bloo , D. M., Wyn-Jones, E.,
Eds.; NATO ASI Se ies: Se ies C, Ma hema ical and Physical Sciences
324;Kluwe Academic Publishe s: Bos on, 1990; pp 385396.
(27) Yamaguchi, Y.; Hoffmann, H. Colloids Su ., A 1997,
121,67–80.
(28) Kahlwei , M.; S ey, R.; Haase, D.; Kunieda, H.; Schmeling, T.;
Faulhabe , B.; Bo ko ec, M.; Eicke, H. F.; Busse, G.; Egge s, F.; Funck,
T.; Richmann, H.; Magid, L.; Sode man, O.; S ilbs, P.; Winkle , J.;
Di ich, A.; Jahn, W. J. Colloid In e ace Sci. 1987,118, 443–444.
(29) Uh meis e ,P.Selbs o ganisie endeNe zwekeinMik oemulsionen.
Ph.D. Thesis, Uni e si €a K€oln, 2002.
(30) Hoffmann, H.; Abdel-Rahem, R. Colloid Polym. Sci 2010,
288, 603–612.
(31) Hoffmann, H.; Ulb ich , W. J. Colloid In e ace Sci. 1989,
129, 388–405.
(32) Lich e eld, F.; Schmeling, T.; S ey, R. J. Phys. Chem. 1986,
90, 5762–5766.
80

S1
Dynamic P ope ies o Mic oemulsions in he Single Phase Channels
Suppo ing In o ma ion
Lukas Wol *1, Heinz Ho mann1, Wal e Rich e 2, Takashi Teshigawa a3, Toh u Okamo o3
1Uni e si y o Bay eu h, BZKG and BayColl, Go lieb-Keim-S . 60, 95448 Bay eu h, Ge many
2F ied ich-Schille -Uni e si y, Cen e o Elec on Mic oscopy, Ziegelmühlenweg 1, 07743 Jena, Ge many
3Shiseido Resea ch Cen e , 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama, Japan 224-8558
*co esponding au ho , Tel.: +49-921-50736168, e-mail: [email p o ec ed]
SI1: Phase sequence o bina y su ac an mix u e Mg(DS)2-IT 3
Pic u es a e shown wi hou and be ween c ossed pola ise s o dis inguish be ween bi e ingen
and non-bi e ingen phases. The su ac an mix u e s a s wi h he pu e 15% Mg(DS)2-
solu ion ha is a micella L1-Phase. The sample shows a c ys alline sedimen a 25 °C,
whe eas he samples wi h a mass ac ion x IT 3 o 0.1 and 0.2 a e iso opic. This shows, ha
he K a -Tempe a u e o he Mg(DS)2, ha is close o 25 °C, is lowe ed by he co-su ac an
IT 3. The iso opic micella L1- egion is ollowed by a wo-phase L1/Lα-si ua ion om x IT 3
0.3 – 0.4. F om x IT 3 0.5 – 0.77, a la ge single bi e ingen Lα egion is p esen ha u ns in o
an iso opic L3-phase a a na ow composi ion ange o x IT 3 ~ 0.78 – 0.79. The sample wi h
15% IT 3 (x IT 3 = 1) shows a wo phase si ua ion wi h a lowe L1 and an uppe L2-Phase
(in e se micella s uc u e).
SI1: Phase sequence o he su ac an mix u e Mg(DS)2/IT 3 a 15% (w/w) su ac an and 25
°C, 20% glyce ine in H2O. x IT 3 indica es he mass ac ion o he non-ionic co-su ac an in
he su ac an mix u e. Lowe ow: samples shown in be ween c ossed pola ise s.
81
S2
SI2: Rheology measu emen s o he su ac an mix u es wi hou oil
Rheog ams o he su ac an mix u es a e shown when no oil has been solubilised bu when
he ac ion o IT 3 is inc eased o cons an su ac an concen a ion o 15%. Sample
composi ion and measu emen condi ion is gi en in each g aph.
The heog am o he sample wi h x IT 3 0.2 (L1-Phase) shows he ypical cha ac e is ics o a
iscous New onian solu ion, whe e he s o age modulus G’ and he loss modulus G’’ a e
inc easing wi h equency and he iscosi y η s ays independen o he equency. The high
iscosi y o a ound 110 mPas is an indica ion o he p esence o long en angled wo m-like
micelles.
0,01 0,1 1
1E-5
1E-4
1E-3
0,01
0,1
1
10
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
0,01
0,1
1
η
[Pas]
x IT 3 0.2
τ = 0.5 Pa
0,01 0,1 1
0,1
1
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
0,01
0,1
1
x IT 3 0.75
τ = 0.03 Pa
η
[Pas]
0,01 0,1 1 10
0,1
1
10
100
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
1
10
100
1000
x IT 3 0.7
τ = 0.5 Pa
η
[Pas]
0,01 0,1 1
1E-6
1E-5
1E-4
1E-3
0,01
0,1
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
0,01
0,1
x IT 3 0.79
τ = 0.1 Pa
η
[Pas]
0,01 0,1 1 10
1
10
100
1000
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
1
10
100
1000
x IT 3 0.5
τ = 0.5 Pa
η
[Pas]
0,01 0,1 1
1E-3
0,01
0,1
1
G' [Pa]
G'' [Pa]
η [Pas]
G',G'' [Pa]
[Hz]
0,01
0,1
1
x IT 3 0.75
τ
= 0.1 Pa
η
[Pas]
82
S3
Rheog ams o he Lα-phases show di e en ea u es. The s abili y egion o he Lα-phases
eaches om a weigh ac ion o IT 3 om 0.5 o 0.75. I is no ewo hy ha he heological
p ope ies o he phases a y conside ably. A x IT 3 0.5 – 0.7, he phases beha e like so
gels. These phases ha e a heological yield s ess. The s o age modulus is equency
independen and abou an o de o magni ude highe han he loss modulus. Samples o hese
phases can he e o e be used o he p epa a ion o s able emulsions o dispe sions. The
dispe sed pa icles o oil d ople s, o e en ai bubbles, canno sedimen o up-c eam. The
sys ems can be de o med a leas 10% be o e hey s a lowing.
Wi h inc easing mass ac ion o IT 3, he s o age modulus o he phases dec eases o e a
wide egion o he composi ion. The a he high s o age modulus is p obably a esul o he
ionic cha ge o he bilaye phases. I is he e o e he mo e ema kable ha i dec eases
d ama ically when he composi ion o he Lα-phase app oaches he phase bounda y o he L3-
phase. Wi h x IT 3 = 0.75, he s o age modulus d ops o alues below 1 Pa and becomes e en
equency dependen a highe shea s ess and he phase no longe beha es like a weak gel,
bu mo e like a New onian solu ion. The eason o his e ec lies in a change o he
nanos uc u e om mul ilamella esicles o plana lamellas wi h inc easing mass ac ion o
IT 3. A x IT 3 0.79, he heog am o he L3-Phase shows he ypical ea u es o a low
iscous New onian luid.
Measu emen s wi h inc easing and dec easing shea a es we e done o in es iga e he
s abili y o he Lα-Phases.
Viscosi y η and shea s ess τ in dependency o shea a e
γ
&o samples a x IT 3 0.5 (le ) and
x IT 3 0.75 ( igh ). Cu es o inc easing shea a e indica ed wi h black a ows o he igh ,
o dec easing shea a e wi h black a ows o he le . Hys e esis e ec o sample wi h x IT 3
0.75 indica ed wi h ed a ow.
The da a o iscosi y and shea s ess o in- and dec easing shea a es o he sample a x IT 3
0.5 lie pe ec ly oge he . This shows ha he gel, and hus i s nanos uc u e, doesn’ ge
des oyed o changed when high shea a es a e applied o he sample. The si ua ion becomes
e y di e en close o he phase bo de o he L3-Phase wi h highe mass ac ion o IT 3. In
con as o he sample wi h x IT 3 0.5, he cu es o he sample wi h x IT 3 0.75 show an
eno mous hys e esis e ec . Fo inc easing shea a es, he iscosi y i s dec eases, bu hen
eco e s a a highe le el wi h dec easing shea a es. This shea hickening e ec could be
explained by he ans o ma ion o plana lamellas o mul ilamella esicles due o high shea .
The s uc u e elaxes o i s o iginal s a e wi hin one o wo hou s.
0,1 1 10 100
0,1
1
10
100
τ
[Pa]
η
[Pas]
τ
[Pa]
.
γ
[1/s]
.
0,1
1
10
x IT 3 0.75
η [Pas]
Hys e esis
0,1 1 10 100
10
100
τ
[Pa]
η
[Pas]
γ
[1/s]
τ
[Pa]
0,1
1
10
100
x IT 3 0.5
η
[Pas]
.
83
S4
SI3: Rheology measu emen s in he Lα-channel wi h inc easing oil con en
Rheog ams o samples in Lα-channel wi h inc easing mass ac ion o oil a e shown. Sample
composi ion is gi en in each g aph.
All samples along he Lα-channel beha e like so gels. A he sample wi h x decane 0.9, a
e y low equencies he iscous p ope ies a e dominan while a equencies > 0,1 Hz he
elas ic p ope ies a e dominan .
A plo o he s o age moduli G’ (a a equency o 1 Hz) o he lamella phases agains he oil
con en is shown in he nex pic u e. Wi h inc easing solubilisa ion o decane, he le el o
s o age modulus G’ dec eases mo e han wo o de s o magni ude om abou 130 Pa a he
sample wi hou decane o 0,4 Pa a he sample wi h x decane 0.9.
0,01 0,1 1 10
1
10
100
1000
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
1
10
100
1000
η
[Pas]
x IT 3 0.55
x decane 0
0,01 0,1 1 10
1
10
100
1000
x IT 3 0.55
x decane 0.2
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
0,1
1
10
100
1000
η
[Pas]
0,01 0,1 1 10
0,1
1
10
100
G'
[Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
0,1
1
10
100
x IT 3 0.65
x decane 0.5
η
[Pas]
0,01 0,1 1 10
0,01
0,1
1
G' [Pa]
G'' [Pa]
η
[Pas]
G',G'' [Pa]
[Hz]
0,01
0,1
1
x IT 3 0.7
x decane 0.9
η
[Pas]
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9
1
10
100
G' [Pa]
x decane G' [Pa]
0,45
0,50
0,55
0,60
0,65
0,70
0,75
sample composi ion
x IT 3
84
S5
Measu emen s wi h in- and dec easing shea a es also whe e done wi hin he Lα-channel.
Two heog ams, one wi h low, he o he wi h high oil con en , a e shown. Cu es o
inc easing shea a e a e indica ed wi h black a ows o he igh , o dec easing shea a e
wi h black a ows o he le . Hys e esis e ec indica ed wi h a ed a ow.
Compa ed o he heog am o he sample wi hou oil a low x IT 3 alues, all samples wi h oil
in he Lα-channel showed a hys e esis e ec . Howe e , he dimension o he hys e esis e ec
becomes smalle wi h inc easing oil con en .
I is concei able ha he oil swollen bilaye s o he Lα-Phases allow luc ua ions ha a e no
possible wi hou oil. A possible candida e o such luc ua ions would be pe is al ic
luc ua ions ha a e luc ua ion o he hickness o he bilaye s.
Ano he signi ican ea u e o he la ge Lα-channel is i s high empe a u e s abili y. Samples
be ween 10 °C and 60 °C be ween c ossed pola ize s a e shown in he nex pic u e.
Samples be ween x decane = 0 – 0.9 a e s able a leas be ween 10 °C – 40 °C, samples wi h
x decane 0 - 0.4 a e e en s able a leas up o 60 °C. Al hough he Lα-channel is qui e na ow,
i s high empe a u e s abili y is amazing. This ea u e is ob ious due o he su ac an mix u e,
whe e he hyd ophilic-lipophilic balance is de e mined mo e by he mass ac ion o he co-
su ac an han by he empe a u e.
0.1 1 10
0.1
1
10
τ
[Pa]
η
[Pas]
γ
[1/s]
τ
[Pa]
0.1
1
10
x IT 3 0.7
x decane 0.9
η [Pas]
.
Hys e esis
0,1 1 10
1
10
100
1000
τ
[Pa]
η
[Pas]
γ [1/s]
τ [Pa]
1
10
100
x IT 3 0.55
x decane 0.2
.
η [Pas]
Hys e esis
85

S6
SI4: Tube pic u es o mic oemulsions o he lowe and uppe single phase channel
Samples wi h 15% (w/w) su ac an a 25 oC and inc easing mass ac ion x o IT 3 and
decane a e shown wi hou pola ize s. Uppe ow: selec ed samples om lowe single phase
channel, lowe ow: selec ed samples om uppe single phase channel.
No e ha samples om he lowe single phase channel a e comple ely anspa en while
samples om he uppe single phase channel a e sligh ly bluish and ha e a high sca e ing
in ensi y a ound x decane 0.03 – 0.1
SI5: Conduc i i y measu emen s in he Lα-channel
The plo o he conduc i i ies in he Lα-channel is shown. Conduc i i y alues a e indica ed as
ed do s, he co esponding IT 3 a ios a e indica ed as g ey iangles. No e ha he
conduc i i y dec eases mo e o less cons an ly wi h inc easing mass ac ion o IT 3 and oil.
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9
1
10
100
1000
conduc i i y [µS/cm]
x decane conduc i i y [µS/cm]
0,45
0,50
0,55
0,60
0,65
0,70
0,75
sample composi ion
x IT 3
86
S7
SI6: EB signals a di e en ield s enghs
EB-signal o a mic oemulsion om he uppe single phase channel wi h 6% decane in he
sol en mix u e, eco ded a di e en ield s eng hs E. No e ha he signals do no depend on
he ield s eng h. The signal iden i ies h ee di e en elaxa ion p ocesses. Du a ion o
elec ic pulse = 1 msec.
SI7: EB-Signals in he uppe single phase channel (x decane 0.005 – 0.1)
Sample composi ion gi en in each g aph. No e he signals become complica ed in he ange
be ween 1 and 10% decane in he sol en mix u e.
0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75 2,00
-1,0x10
-8
-5,0x10
-9
0,0
5,0x10
-9
1,0x10
-8
1,5x10
-8
2,0x10
-8
2,5x10
-8
3,0x10
-8
∆
∆
∆
∆
n
[msec]
E = 91 kVm
-1
0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75 2,00
0,0
2,0x10
-8
4,0x10
-8
6,0x10
-8
8,0x10
-8
1,0x10
-7
E = 181 kVm
-1
∆
∆
∆
∆
n
[msec]
0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75 2,00
0,0
2,0x10
-8
4,0x10
-8
6,0x10
-8
8,0x10
-8
1,0x10
-7
1,2x10
-7
1,4x10
-7
1,6x10
-7
1,8x10
-7
2,0x10
-7
E- ield u ned o
τ3
τ2
E = 273 kVm-1
∆
∆
∆
∆n
[msec]
τ1
E- ield u ned on
τ1
τ2
0 2 4 6 8 10 12 14 16 18 20
-2,50x10
-8
0,00
2,50x10
-8
5,00x10
-8
7,50x10
-8
1,00x10
-7
1,25x10
-7
1,50x10
-7
1,75x10
-7
2,00x10
-7
2,25x10
-7
E = 273 kVm-1
∆
∆
∆
∆
n
[msec]
τL
= 14 msec
0,0 0,1 0,2 0,3 0,4 0,5
-5,0x10
-8
0,0
5,0x10
-8
1,0x10
-7
1,5x10
-7
2,0x10
-7
∆
∆
∆
∆n
[msec]
x IT 3 0.753
x decane 0.005
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0
-5,0x10-8
0,0
5,0x10-8
1,0x10-7
1,5x10-7
2,0x10-7
2,5x10-7
∆
∆
∆
∆
n
[msec]
x IT 3 0.726
x decane 0.01
87
S8
SI8: EB-Signals in he uppe single phase channel (x decane 0.17 – 0.8)
EB-Signals o mic oemulsion o he uppe single phase channel wi h 17 – 80% decane in he
sol en mix u e. Sample composi ion gi en in each g aph. No e ha he signals become
simple again and he main s uc u al elaxa ion ime dec eases wi h inc easing oil con en .
012345678910
-2,0x10
-7
0,0
2,0x10
-7
4,0x10
-7
6,0x10
-7
8,0x10
-7
1,0x10
-6
1,2x10
-6
x IT 3 0.638
x decane 0.17
∆
∆
∆
∆
n
[msec]
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0
-5,0x10
-8
0,0
5,0x10
-8
1,0x10
-7
1,5x10
-7
2,0x10
-7
2,5x10
-7
3,0x10
-7
3,5x10
-7
4,0x10
-7
x IT 3 0.7
x decane 0.3
∆
∆
∆
∆n
[msec]
1 2 3 4 5 6 7 8 9 10
-5,0x10
-8
0,0
5,0x10
-8
1,0x10
-7
1,5x10
-7
2,0x10
-7
2,5x10
-7
∆
∆
∆
∆
n
[msec]
x IT 3 0.684
x decane 0.0225
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
-1,5x10
-7
-1,0x10
-7
-5,0x10
-8
0,0
5,0x10
-8
1,0x10
-7
1,5x10
-7
2,0x10
-7
2,5x10
-7
∆
∆
∆
∆n
[msec]
x IT 3 0.633
x decane 0.04375
0 5 10 15 20 25 30 35 40 45 50
-5,00x10
-8
-2,50x10
-8
0,00
2,50x10
-8
5,00x10
-8
7,50x10
-8
1,00x10
-7
1,25x10
-7
1,50x10
-7
x IT 3 0.613
x decane 0.07875
∆
∆
∆
∆
n
[msec]
0 20 40 60 80 100 120 140 160 180 200
-5,0x10
-8
0,0
5,0x10
-8
1,0x10
-7
1,5x10
-7
2,0x10
-7
2,5x10
-7
x IT 3 0.61
x decane 0.1
∆
∆
∆
∆
n
[msec]
88
S9
SI9: EB-Signals in he lowe single phase channel (x decane 0.1 – 0.4)
EB-signals o he mic oemulsions o he lowe single phase channel. Sample composi ion
gi en in each g aph. No e ha he signals a e less complica ed han signals om he uppe
single phase channel. Main s uc u al elaxa ion ime inc eases wi h inc easing oil con en .
0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75 2,00
-5,00x10
-9
-2,50x10
-9
0,00
2,50x10
-9
5,00x10
-9
7,50x10
-9
1,00x10
-8
1,25x10
-8
x IT 3 0.35
x decane 0.1
∆
∆
∆
∆
n
[msec]
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0
-1,0x10
-8
0,0
1,0x10
-8
2,0x10
-8
3,0x10
-8
4,0x10
-8
5,0x10
-8
6,0x10
-8
7,0x10
-8
8,0x10
-8
x IT 3 0.45
x decane 0.2
∆
∆
∆
∆
n
[msec]
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0
-5,0x10
-8
0,0
5,0x10
-8
1,0x10
-7
1,5x10
-7
2,0x10
-7
2,5x10
-7
3,0x10
-7
3,5x10
-7
x IT 3 0.5
x decane 0.3
∆
∆
∆
∆n
[msec]
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5 6,0 6,5 7,0 7,5 8,0
-2,0x10
-8
0,0
2,0x10
-8
4,0x10
-8
6,0x10
-8
8,0x10
-8
1,0x10
-7
1,2x10
-7
1,4x10
-7
1,6x10
-7
x IT 3 0.55
x decane 0.4
∆
∆
∆
∆n
[msec]
0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75 2,00
-5,0x10-8
0,0
5,0x10-8
1,0x10-7
1,5x10-7
2,0x10-7
2,5x10-7
3,0x10-7
3,5x10-7
4,0x10-7
4,5x10-7
5,0x10-7
5,5x10-7
6,0x10-7
x IT 3 0.8
x decane 0.5
∆
∆
∆
∆n
[msec]
0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75 2,00
-2,50x10-8
0,00
2,50x10-8
5,00x10-8
7,50x10-8
1,00x10-7
1,25x10-7
x IT 3 1
x decane 0.8
∆
∆
∆
∆
n
[msec]
89
ARTICLE
The esul s show a high maximum a a ound 6 % oil. A highe
oil con en he iscosi ies dec ease slowly owa ds he oil side o
he mic oemulsion. The ab up maximum o he iscosi y can be
aken as an indica ion o a s uc u al ansi ion in he channel. The
iscosi y maximum is eached a abou he same oil concen a ion
whe e he conduc i i y disappea ed. Ob iously he ansi ion o
he s uc u e is also exp essed in he iscosi y o he sys em.
The Jou nal o Physical Chemis y B
Fdx.doi.o g/XX.XXXX/jpXXXXXXX | J. Phys. Chem. B XXXX, XXX, 000– 000
Figu e 8. Ze o shea iscosi y, η, agains he mass ac ion o oil o
samples om he uppe single phase channel: a) Viscosi y wi h inc easing
mass ac ion o decane; b) Viscosi y wi h inc easing mass ac ion o iso-
oc ane.
Figu e 7. Rheog ams o he bina y su ac an mix u es a cons an 15%
su ac an (w/w) wi h inc easing mass ac ion x IT 3 a 25 °C. a)
Rheog am o Lαphase a x IT 3 0.7, b) Rheog am o L3phase a x IT 3
0.79.
We showed ha w/o-HIPME s uc u es wi h dimensions o
abou 20 - 100 nm can be he modynamically s able s uc u es in
mic oemulsions. These s uc u es occu in mic oemulsions o med
om su ac an mix u es o anionic and non-ionic su ac an s.
They a e obse ed in he iso opic channel o mic oemulsions,
when small amoun s o oil a e solubilized in o aqueous L3phases.
In spi e o hei small oil con en , he HIMPE phases ha e a
conduc i i y ha is abou 3 - 4 o de s o magni ude lowe han he
conduc i i y o he L3phase. These esul s hus demons a e ha
e y hin su ac an ilms wi h li le oil can p ac ically be
impene able o he anspo o ions. I can be concluded om
he measu emen s ha s uc u al ansi ions can occu in micella
phases, in which bicon inuous s uc u es o non-ionic su ac an s
and oil a e ans o med in o oam-like s uc u es, when he
su ac an laye s a e cha ged by ionic su ac an s. I is likely ha
0,01 0,1 1 10
0,1
1
10
100
G'
[Pa]
G'' [Pa]
η
η
η
η [Pas]
G',G'' [Pa]
[Hz]
a)
1
10
100
1000
x IT 3 0.7
τ
= 0.5 Pa
η
[Pas]
0,01 0,1 1
1E-6
1E-5
1E-4
1E-3
0,01
0,1
G'
[Pa]
G'' [Pa]
η
η
η
η [Pas]
G',G'' [Pa]
[Hz]
0,01
0,1
b)
x IT 3 0.79
τ
= 0.1 Pa
η
[Pas]
0,00 0,05 0,10 0,15 0,20 0,25 0,30 0,35 0,40 0,45 0,50
0
50
100
150
200
250
300
350
400
450
500
a)
η [mPas]
η
η
η
η
[mPas]
x decane
0,00 0,05 0,10 0,15 0,20 0,25 0,30 0,35 0,40 0,45 0,50
50
100
150
200
250
300
350
400
450
500
b)
η [mPas]
η
η
η
η
[mPas]
x iso-oc ane
CONCLUSIONS
such ansi ions can also be p oduced, when he elec ic double-
laye in ionically cha ged sys ems is shielded by excess sal .
AUTHOR INFORMATION
Co esponding Au ho
*Tel:+49-921-50736168. Fax+49-921-50736139. E-mail: lukas.
wol @ eene .de.
ACKNOWLEDGMENT
We hank he Technion Russell Be ie Nano echnology Ins i u e
(RBNI) and he Is ael Science Founda ion (GRANT NO. 962/07)
o pa ial inancial suppo . The elec on mic oscopy was
pe o med a he RBNI Labo a o y o Elec on Mic oscopy o
So Ma e . We hank Judi h Schmid and D . Ellina Kesselman
o hei excellen echnical assis ance, and all membe s o P o .
Talmon’s g oup o hei help.
REFERENCES
(1) S uben auch, C. In Mic oemulsions: Backg ound, New
Concep s, Applica ions, Pe spec i es; Wiley-Blackwell: Chiches e ,
U.K., 2009.
96

ARTICLE
The Jou nal o Physical Chemis y B
Gdx.doi.o g/XX.XXXX/jpXXXXXXX | J. Phys. Chem. B XXXX, XXX, 000– 000
(1) S uben auch, C. In Mic oemulsions: Backg ound, New
Concep s, Applica ions, Pe spec i es; Wiley-Blackwell: Chiches e ,
U.K., 2009.
(2) Monduzzi, M.; Caboi, F.; La ché, F.; Olsson, U. Langmui
1997, 13, 2184-2190.
(3) Be genhol z, J.; Romagnoli, A. A.; Wagne , N. J. Langmui
1995, 11, 1559-1570.
(4) Zemb, T. N.; Hyde, S. T.; De ian, P.-J.; Ba nes, I. S.; Ninham,
B. W. J. Phys. Chem. 1987, 91, 3814-3820.
(5) Ko la chyk, M.; Sheu, E. Y.; Capel, M. Physical Re iew A
1992, 46, 928.
(6) Eas oe, J. Langmui 1992, 8, 1503-1506.
(7) Huang, J. S. J. Su ace Sci. Technol. 1989, 5, 83-131.
(8) Jahn, W.; S ey, R. J. Phys. Chem. 1988, 92, 2294-2301.
(9) S ey, R. Colloid & Polyme Sci. 1994, 272, 1005-1019.
(10) Olsson, U.; Wü z, U.; S ey, R. J. Phys. Chem. 1993, 97,
4535.
(11) Lindman, B.; Shinoda, K.; Olsson, U.; Ande son, D.;
Ka ls öm, G.; Wenne s öm, H. Colloids and Su aces 1989, 38,
205-224.
(12) Kahlwei , M. e al., J. Colloid In e ace Sci. 1987, 118, 445.
(13) Belkou a, L.; S uben auch, C.; S ey, R. Langmui 2004, 20,
4391-4399.
(14) Tlus y, T.; Sa an, S. A.; Menes, R.; S ey, R. Physical
Re iew Le e s 1997, 78, 2616-2619.
(15) Kahlwei , M.; Faulhabe , B.; Busse, G. Langmui 1994, 10,
2528-2532.
(16) Wol , L.; Ho mann, H.; Wa anabe, K.; Okamo o, T. Phys.
Chem. Chem. Phys. 2011, 13, 3248-3256.
(17) Talmon, Y. “Seeing Gian Micelles by C yogenic-
Tempe a u e T ansmission Elec on Mic oscopy (C yo-TEM)”, in
“Gian Micelles”, chap e 5, pp. 163-178, Zana, R. and Kale , E.A.,
Eds., CRC P ess, New Yo k, 2007.
(18) Danino, D.; Be nheim-G oswasse , A.; Talmon, Y. Colloid
Su . A: Physicochem. Eng. Asp. 2001, 183, 113-122.
(19) Danino, D.; Gup a, R.; Sa aya olu, F.; Talmon, Y. J. Colloid
In e ace Sci. 2002, 249, 180-168.
(20) Wol , L.; Ho mann, H.; Rich e , W.; Teshigawa a, T.;
Okamo o, T. J. Phys. Chem. B 2011, 115, 11081-11091.
(21) Mille , C. A.; Raney, K. H. Colloids and Su aces A 1993,
74, 169-215.
(22) So mann, T.; S ey, R. Mic oemulsions, In: Fundamen als
o In e ace and Colloid Science, Lyklema J. Ed., Else ie
Academic P ess, Heidelbe g, Ge many, 2005.
(23) Wehling, A. The dynamics o L3phases. Ph.D. Thesis,
Uni e si y o Cologne, 2001.
(24) Ho mann, H.; Thunig, C.; Munke , U.; Meye , H. W.;
Rich e , W. Langmui 1992, 8, 2629-2638.
(25) Bu aue , S.; Bekou a, L.; S uben auch, C.; S ey, R. Colloid
Su ace A 2003, 228, 159.
(26) Choi, S. M.; Chen, S. H.; So mann, T.; S ey, R. Physica B
1997, 241, 976.
(27) Came on, N. R.; She ing on, D. C. Ad ances in Polyme
Science, 1996, 126, 163-214.
(28) Ho mann, H.; Ebe , G. Angewand e Chemie 1988, 27,
902-912.
(29) Ninham, B. W.; Chen, S. J.; E ans, D. F. J. Phys. Chem.
1984, 88, 5855-5857.
(30) Ben Ba ak, I.; Talmon Y., Langmui (submi ed).
(31) Ho mann, H., Thunig, C.; Schmiedel, P.; Munke , U.
Langmui 1994, 10, 3972-3981.
(32) Uh meis e , P. Selbs o ganisie ende Ne zwe ke in
Mik oemulsionen, Ph.D Thesis, Uni e si y o Cologne, 2009.
(33) Mille , C. A.; G adzielski, M.; Ho mann, H.; K äme U.;
Thunig, C. P og . in Coll. & Polym. Sci. 1991, 84, 243
(34) Faulhabe , B. J. Colloid In e . Sci. 1987, 118, 443-444.
97
PFG-NMR in he Single Phase Channels o Mic oemulsions wi h an anionic/non-ionic su ac an mix u e
98
5.1.5. PFG-NMR in he Single Phase Channels o Mic oemulsions wi h an anionic/non-
ionic su ac an mix u e
Lukas Wol *, Heinz Ho mann, Jü gen Linde s and Ch is ian Maye
* co esponding au ho
Submi ed o So Ma e in Decembe 2011
cu en s a us: unde e ision
DOI:.- - -
CREATED USING THE RSC ARTICLE TEMPLATE (VER. 3.1) - SEE WWW.RSC.ORG/ELECTRONICFILES FOR DETAILS
Pape www. sc.o g/so ma e | So Ma e
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So Ma e , [2011],
[ ol]
, 00–00 |
1
PFG-NMR Sel Di usion Measu emen s in he Single Phase Channels o
a Mic oemulsion Sys em wi h an Anionic/Nonionic Su ac an Mix u e
Lukas Wol ,*a Heinz Ho mann,*a Jü gen Linde s*b, Ch is ian Maye *b
Recei ed (in XXX, XXX) X h XXXXXXXXX 200X, Accep ed X h XXXXXXXXX 200X
Fi s published on he web X h XXXXXXXXX 200X
DOI: 10.1039/b000000x
The single phase channels o a p esen ly epo ed mic oemulsion sys em we e in es iga ed by
elec ical conduc i i y and pulsed- ield g adien nuclea magne ic esonance (PFG-NMR)
spec oscopy. The sys em consis s o a mixed anionic/non-ionic su ac an mix u e, wa e and
decane. A cons an su ac an concen a ion and empe a u e, he phase diag am exhibi s wo
single phase mic oemulsion channels, sepa a ed by an aniso opic lamella channel. The lowe
mic oemulsion channel s a s om he wa e side a he phase diag am wi h a micella L1 phase
and eaches wi h inc easing mass ac ion o decane in he sol en mix u e and inc easing mass
ac ion o lipophilic co-su ac an in he su ac an mix u e he middle o he phase diag am. The
uppe mic oemulsion channel passes om he aqueous side wi h an L3 phase o he oil side o he
diag am. Conduc i i y da a and sel di usion coe icien s, ob ained by PFG-NMR, suppo he
p e iously made conclusion, ha he nanos uc u e in he uppe channel unde goes an ab up
ansi ion om a bicon inuous s uc u e o a wa e -in-oil High In e nal Phase Mic oemulsion
(HIPME) wi h al eady less han 10% o oil in he sol en mix u e, while he s uc u es in he lowe
mic oemulsion channel a e oil-in-wa e d ople s. The HIPME s uc u e is a ea u e o he
su ac an mix u e and p obably due o a high in e acial ension be ween he aqueous dilu ed
su ac an phase and he oil. By addi ion o sal , he HIPME s uc u es a e ob iously dis u bed,
esul ing in an inc eased conduc i i y and a as e di usion a e o he wa e ac ion.
In oduc ion
Since hei disco e y in 1943 by Hoa and Schulman,
mic oemulsions we e much in he ocus o in e es by
scien is s in he ield o colloid and polyme science.1 They
de ined mic oemulsions as op ically iso opic anspa en
phases, consis ing o oil, wa e and su ac an s.2 In con as o
o dina y emulsions, mic oemulsions a e he modynamically
s able.3 Th ee di e en ypes o nanos uc u es can be
dis inguished in mic oemulsions, namely oil d ople s in a
con inuous wa e phase (o/w), wa e d ople s in a con inuous
oil phase (w/o) and bicon inuous s uc u es.4 The ype o he
used su ac an plays an impo an ole o he eme ging
nanos uc u es. The mos de ailed in es iga ed mic oemulsion
sys ems a e hose wi h a single non-ionic su ac an CiEj,
wa e and oil. In such sys ems, i is possible o pass om
wa e - ich o oil- ich single phase mic oemulsions, wi hou
c ossing a phase bounda y in he phase diag am.5 In o de o
s ay in he single phase egion, one has o adap he
hyd ophilic lipophilic balance (HLB) by changing he
empe a u e, as non-ionic su ac an s a e e y empe a u e
sensi i e.6 The beha iou and he nanos uc u es in hese
single-phase channels a e known and heo e ically well
unde s ood.7 They ha e been in es iga ed indi ec ly by
elec ical conduc i i y, small angle neu on sca e ing
(SANS), NMR and di ec ly imaged by eeze ac u e
ansmission elec on mic oscopy (FF-TEM).8-10 Wi h
inc easing empe a u e and inc easing oil con en , he
s uc u e unde goes a con inuous ansi ion om small oil
d ople s in wa e a he aqueous side o a bicon inuous
s uc u e a he middle o he phase diag am wi h equal
amoun s o oil and wa e o small wa e d ople s in oil a he
oil side.11 The s uc u al ansi ion is caused by he change o
he amphiphilic p ope ies o he non-ionic su ac an wi h
ising empe a u e. Thus, he cu a u e o he amphiphilic
monolaye changes om con ex, o la , o conca e.
The si ua ion is somewha di e en in mic oemulsions
p epa ed wi h ionic su ac an s. In such sys ems, i is no
possible o pass om he single aqueous phase o he oil phase
wi hou c ossing phase bounda ies a cons an su ac an
concen a ion.12 The bes known sys ems wi h ionic
su ac an s a e p obably mic oemulsions wi h sodium bis(2-
e hylhexyl) sul osuccina e (AOT), decane o di-dodecyl-
dime hylammoniumb omide (DDAB), dodecane and wa e .13-
14 In con as o bicon inuous mic oemulsions wi h a single
nonionic su ac an , in hese sys ems a w/o d ople s uc u e is
p esen a equal amoun s o wa e and oil.15
We epo ed ecen ly a new mic oemulsion sys em wi h a
mixed anionic/nonionic su ac an mix u e.16 In such sys ems
i is possible o pass om he aqueous o he oil side in a
single phase mic oemulsion channel a cons an su ac an
concen a ion and cons an empe a u e. This is achie ed by
changing he HLB no by empe a u e bu by adjus ing he
su ac an -co-su ac an a io. Conduc i i y da a, elec ic
bi e ingence measu emen s and c yo-TEM pic u es indica ed
ha he nanos uc u e in his single phase channel has a w/o-
s uc u e a a wa e /oil a io o 1/1 and no a bicon inuous
99
2
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This jou nal is © The Royal Socie y o Chemis y [2011]
s uc u e as achie ed wi h a single non-ionic su ac an . We
called his s uc u e High In e nal Phase Mic oemulsion
(HIPME). Fu he mo e, he ansi ion om a bicon inuous L3
phase o a w/o high in e nal phase mic oemulsion seemed o
be al eady comple ed by solubilising less han 10% oil in o
he sys em.17-19 In his in es iga ion, we wan o p o e by
pulsed- ield g adien nuclea magne ic esonance (PFG-NMR)
ha his is in deed he case. Mo eo e we in es iga ed he
in luence o he addi ion o excess sal o he mic oemulsion
sys em by in e acial ension measu emen s, conduc i i y and
PFG-NMR, as i was ied o ans o m he HIPME s uc u es
o bicon inuous s uc u es by shielding he cha ge o he
anionic su ac an .
Resul s and Discussion
Su ace and In e acial Tension Measu emen s
The bina y su ac an mix u e o ou epo ed mic oemulsion
sys em is composed o he hyd ophilic anionic su ac an
Magnesium Dodecyl Sul a e Mg(DS)2 and he lipophilic non-
ionic co-su ac an Iso- idecyl- ie hylenglycole he IT 3
(C13E3). We chose he Mg-sal o SDS, as i is known o cause
lowe su ace ension alues han SDS and i is possible o
o m sponge like L3 phases wi h co-su ac an s.20-21 The
su ace ension and he in e acial ension be ween he
aqueous su ac an and he oil phase play an impo an ole o
he o ma ion o mic oemulsions wi h non-ionic su ac an s.22
Op imal solubilisa ion o oil should occu when he in e acial
ension o he dilu e su ac an solu ion has i s lowes
in e acial ension agains he oil phase.23 Low in e acial
ension alues a e obse ed o su ac an sys ems which o m
liquid c ys alline Lα o L3 phases a low su ac an
concen a ions.24 Be o e we de e mined he in e acial ension
alues be ween ou su ac an mix u e and he oil decane, we
i s in es iga ed he su ace ension o he su ac an mix u e
a a mixing a io o 1/1 (w/w) wi h inc easing su ac an
concen a ion.
Fig. 1 Su ace ension o he su ac an mix u e Mg(DS)2-IT 3 a
a su ac an a io o 1/1 (w/w) wi h inc easing o al su ac an
concen a ion a 25 °C.
As i can be seen in Fig. 1, he su ac an mix u e eaches i s
c i ical micelle concen a ion (cmc) a a alue a ound 0,025%
su ac an and eaches a e y low su ace ension o ~ 26
mN/m. This is in deed a e y low alue, i one conside s he
su ace ension o SDS a ound 35 mN/m abo e i s cmc.
In Fig. 2 we show he in e acial ension alues o he dilu ed
su ac an mix u es wi h inc easing mass ac ion o he co-
su ac an IT 3 a cons an su ac an concen a ion o 0,5%
su ac an agains he oil decane.
Fig. 2 In e acial ension o Mg(DS)2-IT 3 wi h inc easing mass
ac ion x IT 3 in he su ac an mix u e agains he oil decane.
Su ac an concen a ion cons an a 0,5%, measu ed a 25 °C.
A b oad minimum o he in e acial ension is eached
be ween x IT 3 = 0,4 – 0,5 wi h a alue o ~ 2,3 mN/m. In his
a ea, he bina y su ac an mix u e s a s o o m single phase
liquid c ys alline Lα phases a highe su ac an
concen a ions.18 The da a a e e y simila compa ed o a
p e iously in es iga ed mic oemulsion sys em wi h a silicone
oil.16 In con as o mic oemulsions wi h a single non-ionic
su ac an , whe e ul a-low in e acial ensions in he ange o
10-3 mN/m a e eached, he alues wi h ou su ac an sys em
a e e y high. The eason o his ob iously lies in he cha ge
o he anionic su ac an . In sys ems wi h ionic su ac an s, i
should be possible o lowe he in e acial ension by shielding
he elec ic cha ge wi h excess sal .25
Phase Diag am o Mg(DS)2/IT 3 – H2O/n-Decane
A phase diag am o ou in es iga ed mic oemulsion sys em is
shown in Fig. 3. The o al su ac an concen a ion was kep
cons an a 15% (w/w) and he empe a u e a 25 oC. Samples
we e p epa ed wi h 20% glyce ine in H2O o p e en eezing
a e ac s in eeze ac u e ansmission elec on mic oscopy
(FF-TEM) in es iga ions, ha we e done p e iously.18 The
phase diag am con ains wo iso opic mic oemulsion
channels, a lowe one and an uppe one. The uppe one begins
on he su ac an axis a he egion o he L3 phase. Wi h
inc easing oil, he channel i s shi s o a lowe IT 3 a io and
hen again o a highe IT 3/Mg(DS)2 a io o highe oil a ios.
I ends on he oil side a 80% decane and pu e IT 3 as
su ac an . The lowe channel begins a he L1 egion and ends
in he middle o he phase diag am a an IT 3 a io o 0.57.
Bo h channels a e sepa a ed by a la ge single phase
bi e ingen Lα egion ha ex ends om 0% o 90% decane
wi h sligh ly inc easing mass ac ion o IT 3.
1E-3 0,01 0,1 1
25
30
35
40
45
50
55
60
65
su ace ension [mN/m]
su ac an concen a ion [%] su ace ension
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0
0
1
2
3
4
5
6
7
8
9
10
11
12
in e acial ension [mN/m]
x IT 3 in e acial ension
100
This jou nal is © The Royal Socie y o Chemis y [2011]
So Ma e , [2011],
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3
Fig. 3 Phase diag am o sys em Mg(DS)2/IT 3 – H2O/decane a
15% (w/w) su ac an and 25 oC, 20% glyce in in H2O. x IT 3 =
mass ac ion o IT 3 in he su ac an mix u e, x decane = mass
ac ion o decane in he sol en mix u e. “ME” indica es
iso opic mic oemulsion a ea, Lα indica es a ea o aniso opic
lamella channel.
The mic oemulsions in he lowe single phase channel a e
anspa en phases ha show no low bi e ingence unde
shea . The samples in he uppe phase channel ha e di e en
p ope ies. While he L3 phase wi hou decane is comple ely
anspa en , he samples wi h decane look somewha bluish
and hei sca e ing in ensi y is mos in ensi e a ound x
decane 0.03 and 0.1. Fo highe oil con en he sca e ing
in ensi y is dec easing again.
A good and quick me hod ha gi es i s indica ions o he
nanos uc u es in mic oemulsions is he measu ing o he
elec ic conduc i i y. I helps o dis inguish be ween
conduc ing wa e con inuous phases and non-conduc ing oil
con inuous phases.26 Because we use a su ac an mix u e wi h
an anionic su ac an , no addi ional sal has o be added o
ollow he conduc i i y in he phases in con as o
mic oemulsions wi h only a single non-ionic su ac an . The
plo s o he conduc i i ies in he uppe and lowe single phase
channels a e shown in Fig. 4a and 4b. In he uppe channel,
he conduc i i y i s inc eases sligh ly om a ound 1000
µS/cm o he sample wi hou decane o 1160 µS/cm o he
sample wi h 1% decane. The eason o his lies in he change
o he composi ion o he su ac an mix u e. In he ange
om 1% - 10% decane, he conduc i i y dec eases ab up ly
h ee o de s o magni ude o 1µS/cm e en hough he ac ion
o he anionic Mg(DS)2 is inc easing. Fo highe mass
ac ions o decane, he conduc i i y alues dec ease
con inuously o low alues as e.g. 0.03 µS/cm o he sample
wi h a wa e /oil a io o 1/1 (w/w). The conduc i i ies hus
indica e a d ama ic change in he nanos uc u e o he uppe
channel wi h solubilisa ion o small amoun s o oil in o he L3
phase. The ab up collapse o he conduc i i y indica es ha
he sys em changes om a bicon inuous s uc u e o a wa e -
in-oil (w/o) s uc u e. Conduc i i ies in he iso opic channels
o mic oemulsions om non-ionic su ac an s ha e been
epo ed in he li e a u e.27 In such sys ems, he conduc i i y
in he uppe channel dec eases con inuously wi h inc easing
oil con en . These measu emen s ha e helped o es ablish he
iew which we ha e oday om he s uc u es in he uppe
channel. Wi h inc easing oil con en , he bicon inuous L3
phase swells wi h he solubilised oil be ween he bilaye s and
is inally ans o med a high oil con en o a w/o sys em.
Fig. 4 Plo o conduc i i y ( ed do s) and IT 3 con en (g ey
iangles) agains mass ac ion o decane in sol en mix u e. a)
Conduc i i y da a o he uppe single phase channel. b)
Conduc i i y da a o he lowe single phase channel.
Wi h equal amoun o oil and wa e , SANS-da a and con-
duc i i ies show, ha his phase is s ill a bicon inuous phase.28
Ou conduc i i y da a unambiguously show ha he s uc u es
in he uppe channel o he p esen ly in es iga ed sys em a e
di e en om he s uc u es o known sys ems wi h non-ionic
su ac an s. We ind a a he ab up ansi ion om he bicon-
inuous L3 s uc u e o a w/o s uc u e wi h only 10% o oil in
he sol en mix u e. Recen ly published c yo-TEM pic u es
show a polyhed al w/o oam s uc u e, when 6% o oil was so-
lubilised in he L3 phase.19 These s uc u es we e simila o
hose ha a e ound in so called High In e nal Phase Emulsi-
ons (HIPE).29 We he e o e called he new mic oemulsion
s uc u es High In e nal Phase Mic oemulsions (HIPME).
In opposi ion o he uppe channel, he conduc i i y da a o
he lowe channel indica e ha he nanos uc u e in he lowe
channel does no change much wi h inc easing oil con en . A
he wa e co ne , he conduc i i y in he lowe channel wi h
2900 µS/cm is much highe han he conduc i i y o he L3
phase o he uppe channel wi h 1000 µS/cm. The eason o
his is ha he Mg(DS)2 concen a ion is much highe in he
lowe channel. Wi h inc easing oil con en , he conduc i i ies
dec ease sligh ly o 1500 µS/cm a he middle o he phase
0,0 0,1 0,2 0,3 0,4 0,5
0,01
0,1
1
10
100
1000
conduc i i y [µS/cm]
x decane conduc i i y [µS/cm]
a)
0,60
0,65
0,70
0,75
0,80
sample composi ion
x IT 3
0,0 0,1 0,2 0,3 0,4
10
100
1000
conduc i i y [µS/cm]
x decane conduc i i y [µS/cm]
0,10
0,15
0,20
0,25
0,30
0,35
0,40
0,45
0,50
0,55
0,60
sample composi ion
x IT 3
b)
101

4
| So Ma e , [2011],
[ ol]
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This jou nal is © The Royal Socie y o Chemis y [2011]
diag am, which is whe e he channel ends. The eason o he
dec ease is mainly he dec easing mass ac ion o Mg(DS)2.
Ob iously, he lowe channel consis s o a con inuous wa e
phase in which oil d ople s a e dispe sed (o/w-s uc u e).
PFG-NMR in he Mic oemulsion Channels
To unde line and o e i y ou esul s, we in es iga ed he
mic oemulsion channels by PFG-NMR, as his me hod
deli e s in o ma ion abou he s uc u e, luidi y and emulsion
ype. Fu he mo e, i can gi e indica ions abou he in e ac ion
be ween su ac an and co-su ac an a he in e ace. Fig. 5
shows a con en ional p o on NMR spec um o he sys em in
he uppe channel a x decane 0.7, x IT3 0.85.
Fig. 5 P o on NMR spec um o he sys em in he uppe channel
a x decane 0.7, x IT3 0.85.
The PFG-NMR analysis is ocussed on hose spec al egions
which can ei he be clea ly assigned o single sys em
cons i uen s (wa e be ween 4.8 and 5.3 ppm and decane
be ween 1.3 and 2.0 ppm) o o he mix u e o he su ac an s
(Mg(DS)2/IT3 be ween 0.2 and 0.4 ppm). The in eg als o
hese h ee spec al egions s ongly depend on he s eng h o
he g adien pulse, he eby indica ing he a e age displacemen
o he co esponding sys em cons i uen s du ing he pe iod
be ween he pulses which was se o 50 ms. In a plo o he
loga i hmic ela i e signal in ensi y ln I/I0 s. he pa ame e
γ²G²δ²(∆-δ/3) (wi h γ being he gy omagne ic a io o p o ons,
G he s eng h o he g adien ield, δ and ∆ he du a ion o
and he spacing be ween he wo g adien pulses), he slope is
equal o he nega i e appa en sel di usion coe icien o he
gi en componen in he he e ogeneous sys em (S ejskal-
Tanne plo ). I he componen is loca ed in wo di e en en-
i onmen s leading o clea ly di e en sel di usion p ope -
ies, he plo will show wo sec ions wi h clea ly di e en
slopes. I he componen is encapsula ed in e y small
d ople s, he mo ion wi hin he d ople s becomes unde ec able.
In his case, he obse ed slope e lec s he di usi e dislo-
ca ion connec ed o he B ownian mo ion o he d ople s.
The esul ing S ejskal-Tanne plo s o ou di e en s a es in
he uppe channel a e shown in Fig. 6. The co esponding ap-
pa en sel di usion coe icien s a e lis ed in Table 1. The
i s example (Fig. 6 a) e e s o he si ua ion in absence o de-
cane (x decane 0). He e, he wa e signal ollows a s eep
decay, co esponding o a sel di usion cons an o Dw =
6.80·10-10 m²/s. This is jus sligh ly lowe han he alue o
bulk wa e , indica ing ha wa e o ms a con inuous phase
only sligh ly a ec ed by dispe sed phase bounda ies. In
con as , he signal o Mg(DS)2/IT3 ollows a ela i ely la
decay, poin ing o a s uc u e o he su ac an which only
allows a es ic ed mobili y o Mg(DS)2 and IT 3 molecules.
The si ua ion changes signi ican ly on he addi ion o 10%
decane (x decane 0.1, Fig. 6 b). Now he mobili y o wa e is
educed by a ac o o h ee o Dw = 2.22·10-10 m²/s. All o he
sys em cons i uen s, decane as well as he su ac an s, exhibi
cu ed decay p o iles connec ed o wo dis inc ly di e en
di usion cons an s o each cons i uen . The la ges po ion o
decane (and a small po ion o he su ac an s) show a sel -
di usion cons an which, wi h Dd = 3.65·10-10 m²/s, is
app oxima ely hal o he alue o bulk decane. Wi h he
ela i ely small decane con en , his indica es ha we ac ually
deal wi h a con inuous decane phase. The slowe po ion o
he decane (app oxima ely 3%) seems o be associa ed wi h
he majo i y o he su ac an (Dd = 5.68·10-11 m²/s).
Al oge he , he di usion p o ile is compa ible wi h a high
in e nal phase w/o-mic oemulsion (w/o-HIPME) o 90% wa e
in 10% decane, s abilized by he su ac an s. Ob iously, a
small ac ion o he decane is closely associa ed wi h he
su ac an laye which explains he slow ac ion o decane.
Co espondingly, some o he su ac an is being dissol ed in
he decane phase which explains he as ac ion o he
Mg(DS)2/IT 3 signal. The su p isingly high di usion a e o
he wa e indica es signi ican exchange o wa e molecules
ia he hin decane ilms which sepa a e he wa e d ople s.
Wi h inc easing decane con en (x decane 0.3 and 0.7), he
sys em g adually changes owa ds a con en ional wa e in oil
mic oemulsion (Figs. 6 c and d). The mobili y o wa e is u he
educed by an o de o magni ude o Dw = 2.14·10-11 m²/s and Dw
= 2.13·10-11 m²/s, espec i ely. In addi ion, he mobili y o he
su ac an as well as he “slow” ac ion o he decane is slowed
down by a ac o o i e (Dd = 1.02·10-11 m²/s and Dw = 8.76·10-
12 m²/s o x decane 0.3 and 0.7). In con as , he “ as ” ac ion o
he decane exhibi s alues which now come close o he bulk
di usion a e (Dd = 4.32·10-10 m²/s and Dd = 7.07·10-10 m²/s o x
decane 0.3 and 0.7). In his si ua ion, he obse ed disloca ion o
wa e molecules is la gely caused by he B ownian mo ion o
small wa e d ople s in he con inuous decane phase. Wi h he
gi en iscosi y o decane a oom empe a u e, he diame e o
he wa e d ople s can be es ima ed o app oxima ely 20 nm. As
be o e, we assume ha pa o he su ac an is dissol ed in he
con inuous decane phase, leading o he ini ial as decay o he
Mg(DS)2/IT 3 signal. Also, again a small ac ion o he decane is
dissol ed in he su ac an laye a ound he wa e d ople s,
leading o he shallow pla eau o he decane signal (Dd = 1.02·10-
11 m²/s and Dd = 8.76·10-12 m²/s o x decane 0.3 and 0.7,
espec i ely). The ac ha he sel di usion coe icien o wa e
is s ill sligh ly la ge han o he d ople wall cons i uen s
indica es he exchange o a small ac ion o wa e molecules
be ween he d ople s ia he hyd ophobic phase, an e ec which
is linked o Oswald ipening.
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
ppm
wa e
decane
MDS/IT 3
glyce in/MDS/IT 3
decane
/MDS
/IT 3
102
This jou nal is © The Royal Socie y o Chemis y [2011]
So Ma e , [2011],
[ ol]
, 00–00 |
5
Fig. 6 a-d S ejskal-Tanne plo s o decane, wa e and he
su ac an s in he uppe channel.
Tab. 1 Appa en sel di usion coe icien s o sys em cons i uen s in he
uppe channel
x wa e x decane D (wa e ) D (decane) D (decane)
pla eau
[m2/s] [m2/s] [m2/s]
1 0 6.80 10-10 - -
0.9 0.1 2.22 10-10 3.65 10-10 5.68 10-11
0.7 0.3 2.14 10-11 4.32 10-10 1.02 10-11
0.3 0.7 2.13 10-11 7.07 10-10 8.76 10-12
Fig. 7 S ejskal-Tanne plo s o decane, wa e and he su ac an s
in he lowe channel.
Tab. 2 Appa en sel di usion coe icien s o sys em cons i uen s in he
lowe channel
x wa e x decane D (wa e ) D (wa e )
pla eau D (decane)
[m2/s] [m2/s] [m2/s]
0.9 0.1 1.04 10-9 1.79 10-11 1.37 10-11
0.7 0.3 8.36 10-10 9.04 10-12 2.88 10-13
In con as o he esul s o he uppe channel, he a ia ions
be ween he PFG-NMR esul s o di e en posi ions in he
lowe channel do no indica e d ama ic s uc u al changes,
e en hough di usion cons an s do a y signi ican ly wi h x
decane. An example o a co esponding S ejskal-Tanne plo
o he lowe channel is shown in Fig. 7. Appa en sel
di usion coe icien s o wo poin s in he lowe channel a e
lis ed in Table 2. The da a o wa e and he su ac an s
esemble hose o he uppe channel in absence o decane.
Again, he wa e signal shows e y s eep decays linked o sel
di usion coe icien s o 1.04 10-9 m²/s o x decane 0.1 and
8.36 10-10 m²/s o x decane 0.3, alues which come close o
he one in bulk wa e . In con as , he decane signal indica es
an inc easingly slow mobili y (1.37 10-11 m²/s and 2.88 10-13
m²/s) which co esponds o B ownian mo ion o d ople s wi h
inc easing size. The su ac an seems o be linked o he
decane d ople s, e en hough he di usion a e is sligh ly
la ge . All in all, he da a a e clea ly in acco dance wi h an
o/w mic oemulsion wi h a d ople size signi ican ly g owing
wi h he decane con en . Pa s o he su ac an molecules may
0,0 5,0x10
10
1,0x10
11
-10
-8
-6
-4
-2
0
wa e
MDS/IT 3
ln I/I0
γ2G2δ2(∆-δ/3)
0% decane (uppe channel)
a )
0,0 5,0x10
10
1,0x10
11
-10
-8
-6
-4
-2
0
decane
wa e
MDS/IT 3
ln I/I
0
γ
2
G
2
δ
2
(∆-δ/3)
10% decane (lowe channel)
0,0 5,0x1010 1,0x1011
-10
-8
-6
-4
-2
0
decane
wa e
MDS/IT 3
ln I/I0
γ2G2δ2(∆-δ/3)
30% decane (uppe channel)
c )
0,0 5,0x1010 1,0x1011
-10
-8
-6
-4
-2
0
decane
wa e
MDS/IT 3
ln I/I
0
γ2
G
2δ2
(
∆
-
δ
/3)
70% decane (uppe channel)
d )
0,0 5,0x10
10
1,0x10
11
-10
-8
-6
-4
-2
0
decane
wa e
MDS/IT 3
ln I/I
0
γ
2
G
2
δ
2
(∆-δ/3)
10% decane (uppe channel)
b )
103
6
| So Ma e , [2011],
[ ol]
, 00–00
This jou nal is © The Royal Socie y o Chemis y [2011]
Fig. 8 Sel di usion cons an s o sys em cons i uen s in he uppe
channel as a unc ion o he decane and IT 3 con en .
unde go mo e apid di usion ia molecula exchange wi h
micelles which would explain o he sligh de ia ion be ween
he slopes o he decane and he su ac an signals. An
ex emely small ac ion o wa e molecules may be linked o
he d ople s and explain a possible pla eau o he wa e signal
o ln I/I0 < -8. Howe e , wi h a con ibu ion o only 0.01%,
his signal ac ion comes close o he noise ampli ude and
may be insigni ican . All appa en sel di usion cons an s a e
summa ized in Figs. 8 and 9 as unc ions o he decane
con en . The da a o he wa e ac ion show a clea
co ela ion wi h he co esponding conduc i i y plo s in Fig.
4. In he uppe channel, he wa e mobili y s eeply declines
wi h inc easing decane concen a ion (Fig. 8 op).
Fig. 9 Sel di usion cons an s o sys em cons i uen s in he lowe
channel as a unc ion o he decane and IT 3 con en .
This beha io is ep oduced by a co esponding dec ease o
he conduc i i y (Fig. 4 op) which can be ega ded as a di ec
consequence: wi h less mobile wa e molecules, ions in he
aqueous solu ion can be expec ed o be less mobile as well.
Howe e , his e ec is a mo e d ama ic on conduc i i y han
on he mobili y o indi idual wa e molecules: a educ ion o
he sel di usion coe icien by a ac o o 30 esul s in a loss
in conduc i i y by mo e han h ee o de s o magni ude. This
may be pa ially explained by a educed o e all ion concen a-
ion connec ed o he dec easing wa e con en .
In case o he lowe channel, he loss o wa e mobili y unde
inc easing decane con en is much smalle (Fig. 9 op). This is
again e lec ed by he conduc i i y da a in Fig. 4 (bo om)
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7
1x10-10
2x10-10
3x10-10
4x10-10
5x10-10
6x10-10
7x10-10
8x10-10
di [m2/s]
% (x decane)
di [m/s]
0,60
0,65
0,70
0,75
0,80
0,85
0,90
sample composi ion
x IT 3
a )
wa e in he uppe channel
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7
1x10-10
2x10-10
3x10-10
4x10-10
5x10-10
6x10-10
7x10-10
8x10-10
di [m2/s]
% (x decane)
di [m/s]
0,60
0,65
0,70
0,75
0,80
0,85
0,90
sample composi ion
x IT 3
b )
mobile ac ion o decane in uppe channel
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7
1x10
-10
2x10
-10
3x10
-10
4x10
-10
5x10
-10
6x10
-10
7x10
-10
8x10
-10
di [m2/s]
% (x decane)
di [m/s]
0,60
0,65
0,70
0,75
0,80
0,85
0,90
sample composi ion
x IT 3
c )
slow ac ion o decane in uppe channel
0,1 0,2 0,3 0,4
0,0
2,0x10-10
4,0x10-10
6,0x10-10
8,0x10-10
1,0x10-9
1,2x10-9
1,4x10-9
1,6x10-9
di [m
2
/s]
% (x decane)
di
0,10
0,15
0,20
0,25
0,30
0,35
0,40
0,45
0,50
0,55
0,60
sample composi ion
x IT 3
a )
mobile ac ion o wa e in lowe channel
0,0 0,1 0,2 0,3 0,4
0,0
2,0x10
-12
4,0x10
-12
6,0x10
-12
8,0x10
-12
1,0x10
-11
1,2x10
-11
1,4x10
-11
1,6x10
-11
1,8x10
-11
2,0x10
-11
di [m2/s]
% (x decane)
di
0,10
0,15
0,20
0,25
0,30
0,35
0,40
0,45
0,50
0,55
0,60
sample composi ion
x IT 3
b )
slow ac ion o wa e in lowe channel
0,0 0,1 0,2 0,3 0,4
0,0
2,0x10
-12
4,0x10
-12
6,0x10
-12
8,0x10
-12
1,0x10
-11
1,2x10
-11
1,4x10
-11
1,6x10
-11
di [m2/s]
% (x decane)
di
0,10
0,15
0,20
0,25
0,30
0,35
0,40
0,45
0,50
0,55
0,60
sample composi ion
c )
decane in lowe channel
104
This jou nal is © The Royal Socie y o Chemis y [2011]
So Ma e , [2011],
[ ol]
, 00–00 |
7
which show a mino dec ease on addi ion o decane. He e, a
dec ease o he wa e mobili y by a ac o o 1.2 be ween x
decane 0.1 and 0.3 is accompanied by abou he same ac o o
1.25 in conduc i iy. The eason o his lies mainly in he
dec easing mass ac ion o he anionic Mg(DS)2 in he
su ac an mix u e.
In luence o Sal o he Sys em
As al eady men ioned, ou mixed anionic/nonionic su ac an
sys em has a e y high in e acial ension agains he oil phase
compa ed o he ul a-low in e acial ensions ha can be
eached wi h single non-ionic su ac an s. We assumed ha by
shielding he cha ge o he anionic su ac an by adding
excess sal would lowe he in e acial ension.
Fig. 10 in e acial ension o he su ac an mix u es agains
decane wi h inc easing amoun o NaCl. Su ac an concen a ion
cons an a 0,5% in he aqueous phase. 100% NaCl co esponds
o a mola a io o Mg(DS)2:NaCl = 1:1. a) in e acial ension a x
IT 3 = 0.5, b) in e acial ension a x IT 3 = 0.8.
Simila e ec s we e al eady epo ed o he anionic
su ac an die hylhexyl sodium sulphosuccina e (AOT), whe e
ul a-low in e acial ensions agains oil we e eached wi h
addi ional NaCl.25
To e i y ou assump ion, we measu ed he in e acial ension
a wo mixing a ios o he su ac an and co-su ac an wi h
inc easing amoun o NaCl, namely a ound he minimum o
he obse ed in e acial ension a x IT 3 = 0.5 and a ound he
mixing a io o he L3 phase a x IT 3 = 0.8. As i can be seen
in Fig. 10, he in e acial ension is lowe ed only abou 0.5
mN/m a he minimum o he in e acial ension a x IT 3 =
0.5 and only abou 0.9 mN/m a ound he L3 phase a x IT 3 =
0.8, when he mola a io o Mg(DS)2:NaCl in he su ac an
mix u es is aised o 1:1. No ul a-low in e acial ensions
we e de ec ed. As he olume-d op echnique can de ec low
in e acial ensions down o 0.1 mN/m, he e shouldn’ be
any hing w ong wi h he measu emen s. We also checked he
in luence o sal on he phase beha iou o he uppe
mic oemulsion channel. The e o e, we had a close look on
he mic oemulsion wi h 30% decane in he sol en mix u e
and in es iga ed how he phase bounda ies would shi by
adding NaCl o he sys em. I u ned ou ha he uppe and
lowe bo de s o he single phase egion a e shi ed o lowe x
IT 3 alues by x IT 3 ~ 0.07 when we added NaCl o he
Mg(DS)2 in a mola a io o 1:1. The shi o lowe x IT 3
alues means ha he sys em in o al becomes mo e lipophilic,
as less amoun o he lipophilic co-su ac an IT 3 in he
su ac an mix u e is needed o solubilise 30% o decane. I
he shi o he phase bounda ies is accompanied also by a
change in he nanos uc u e was i s in es iga ed by
measu ing he elec ic conduc i i y o he mic oemulsion wi h
inc easing sal concen a ion. A plo o he conduc i i y in he
single phase egion wi h inc easing NaCl concen a ion is
shown in Fig. 11.
Fig. 11 Plo o conduc i i y in he single phase egion o a
mic oemulsion wi h x decane 0.3 and inc easing NaCl
concen a ion a 25 °C. 100% NaCl co esponds o a mola a io
o Mg(DS)2:NaCl = 1:1.
The conduc i i y om he NaCl- ee o he mic oemulsion
wi h a mola a io o Mg(DS)2:NaCl = 1:1 inc eases abou
h ee o de s o magni ude om a low alue o 3 µS/cm o ~
1000 µS/cm. The conduc i i y inc eases in a sigmoid cu e
wi h an in lec ion poin a ound 50% NaCl and no linea ly
wi h inc easing NaCl concen a ion. A i s sigh , he
nanos uc u e seems o change om a w/o-HIPME sys em o a
bicon inuous-like nanos uc u e.
To e i y his, we compa ed wo mic oemulsions wi h
di e en sal concen a ions by PFG-NMR. The i s sample
wi hou NaCl had he composi ion o x IT 3 0.7 and x decane
0.3. The second sample had he composi ion o x IT 3 0.615, x
decane 0.3, and he mola a io o Mg(DS)2:NaCl = 1:1. The
esul ing S ejskal-Tanne plo s a e shown in Fig. 12, he
co esponding appa en sel di usion cons an s a e lis ed in
Table 3.
0 10 20 30 40 50 60 70 80 90 100
2,0
2,1
2,2
2,3
2,4
2,5
2,6
in e acial ension [mN/m]
NaCl [%] in e acial ension
a)
0 10 20 30 40 50 60 70 80 90 100
4,50
4,75
5,00
5,25
5,50
5,75
b)
in e acial ension [mN/m]
NaCl [%] in e acial ension
0 10 20 30 40 50 60 70 80 90 100
1
10
100
1000
conduc i i y [µS/cm]
sample composi ion
NaCl [%]
conduc i i y [µS/cm]
0,61
0,62
0,63
0,64
0,65
0,66
0,67
0,68
0,69
0,70
x IT3
105
E klä ung
112
9. E klä ung
Ich e klä e hie mi , dass ich die o liegende A bei selbs ändig e ass und keine ande en als
die on mi angegebenen Quellen und Hil smi el benu z habe.
Fe ne e klä e ich, dass ich nich ande wei ig mi ode ohne E olg e such habe, diese
Disse a ion einzu eichen. Ich habe keine gleicha ige Dok o p ü ung an eine ande en
Hochschule endgül ig nich bes anden.
Bay eu h, den 5. Dezembe 2011
Lukas Wol