Silicate conductive composites with graphite-based fillers

Con en om his wo k may be used unde he e ms o heC ea i eCommonsA ibu ion 3.0 licence. Any u he dis ibu ion o his wo k mus main ain a ibu ion o he au ho (s) and he i le o he wo k, jou nal ci a ion and DOI. Published unde licence by IOP Publishing L d Young Scien is 2021 IOP Con . Se ies: Ma e ials Science and Enginee ing 1209 (2021) 012035 IOP Publishing doi:10.1088/1757-899X/1209/1/012035 1 Silica e conduc i e composi es wi h g aphi e-based ille s Š Ba ánek1, V Če ný1, G Yako le 2 and R D ochy ka1 1 Facul y o Ci il Enginee ing, Ins i u e o Technology o Building Ma e ials and Componen s, B no Uni e si y o Technology, Ve e i 95, 602 00 B no, Czech Republic 2 Depa men o Geo echnical Enginee ing and Building Ma e ials, Kalashniko Izhe sk S a e Technical Uni e si y, S udencheskaya S . 7, 426009 Izhe sk, Russia E-mail: ba anek[email p o ec ed]u b .cz; ce ny. @ ce. u b .cz; gy[email p o ec ed]; d ochy ka. @ ce. u b .cz Abs ac . Elec oconduc i e composi es a e mode n ma e ials ha a e commonly used in many indus ies such as cons uc ion indus y and machine-building indus y. Fo example, hese ma e ials can be use ul as senso s o moni o ing changes in cons uc ions, shielding s ay cu en s om elec i ica ion ne wo ks, shielding elec omagne ic adia ion in ope a ing ooms, ca hodic p o ec ion agains mois u e o o e ol age p o ec ion o buildings. The opic o his pos is he esea ch o elec ically conduc i e silica e composi es wi h g aphi e-based ille s. In his esea ch will be es ed composi es wi h di e en a io and ypes o g aphi e and moni o hei elec oconduc i e p ope ies like impedance, and physical-mechanical p ope ies like comp essi e and ensile s eng h. The pos desc ibes basic p ope ies and in e ac ions o silica e elec ically conduc i e composi es wi h g aphi e ille s. I was ound ha by adding 10 % w . g aphi e in o silica e composi es, impedance is educed by 50% and comp essi e s eng h by 40%. The lexu al ensile s eng h depends mainly on he oughness o he pa icles, whe e he coa se laky pa icles ans e he load be e and inc ease he s eng h while e y ine g aphi es educe he lexu al ensile s eng h. Fu he mo e, i has been ound ha e y inely g ound syn he ic g aphi es a e mos sui able o achie ing low impedance o composi es. 1. In oduc ion Composi e ma e ials c ea e a wide ange o op ions ha can be used o make a a ie y o ma e ials designed speci ically o cu en ma ke equi emen s, esea ch, and de elopmen . The composi es a e consis ing o wo o mo e subs ances wi h di e en chemical componen s ha di e in physical and mechanical p ope ies. In mos cases, one o mo e subs ances o m a so-called ille , which ep esen s a discon inuous phase in composi e ma e ials. By mixing ille s in o he ma ix, many physical, chemical, and mechanical p ope ies o he composi e ma e ial can be modi ied, such as bulk densi y, comp essi e s eng h, ensile s eng h, bulk s abili y, he mal and elec ical conduc i i y, apo and gas pe meabili y, abso bency, and many o he cha ac e is ics. Ano he bene i o ille s can be a educ ion in p oduc ion cos s. Ano he componen o composi es is a ma ix, which has he main ask o bonding all componen s in o one in eg al ma e ial, o ming a con inuous phase o he ma e ial, and ac ing as a binde . I s unc ion is also o main ain he desi ed shape and a ec s he inal appea ance o he ma e ial. The ma ix con ibu es o he mechanical and physical p ope ies o he en i e composi e ma e ial. I also has he ask o p o ec ing he ille s o ein o cemen om ex e nal in luences, de e mines he he mal conduc i i y, i e esis ance o he composi e and o he s. Ma ices a e mos o en based on silica e ma e ials such as cemen , based on polyme , such as epoxies and polyes e s, o based on geopolyme . Young Scien is 2021 IOP Con . Se ies: Ma e ials Science and Enginee ing 1209 (2021) 012035 IOP Publishing doi:10.1088/1757-899X/1209/1/012035 2 Elec oconduc i e composi es can be de ined as composi es wi h a ce ain ille con en ha p o ide sui able elec oconduc i e p ope ies. Wi h he help o elec ically conduc i e ille s, a s able, pe ec ly elec ically conduc i e ne wo k is c ea ed in he ma e ial, which can conduc elec ic cu en . Fo solid ma e ials, he elec ical conduc i i y can be di ided in o su ace and in e nal conduc i i y. Su ace elec ical conduc i i y depends mainly on he mois u e o he ma e ial, while in e nal conduc i i y is ela ed o he s uc u e, amoun and p ope ies o conduc i e ille s used [1]. As elec ically conduc i e ille s, ca bon-based ille s such as ca bon black, g aphi e, ca bon, ca bon nanopla es o g aphene, ca bon nano ubes, ca bon ubes, mic o-silica and o he s a e mos commonly used, and me al-based ille s such as howe e , s eel wi es, ab ics, o powde s o hese ille s a e less e ec i e and a e no sui able o silica e composi es [1][2][3]. Impedance, analogous o speci ic elec ical esis ance ( esis i i y) is a p ope y o a ma e ial when a di ec cu en passes h ough i , impedance is a " esis ance" o al e na ing cu en . I is a complex quan i y ha consis s o an imagina y and a eal componen . Fo accu a e measu emen , i is necessa y o p ecisely de ine he measu ed quan i ies ( ol age and cu en ). Once he e is a whole, pe ec ly in e connec ed elec ically conduc i e s uc u e in he composi e ma e ial, he impedance o he ma e ial i sel dec eases signi ican ly, his limi is called he pe cola ion h eshold and esul s in he subsequen addi ion o he ma e ial no longe a ec ing he impedance o he composi e [3][4][4]. The p ope ies o silica e composi es signi ican ly depending on he ype and amoun o ille used. Wi h he addi ion o ca bon-based ille s, he e is a signi ican dec ease in physical and mechanical p ope ies bu also a signi ican educ ion in impedance. These p ope ies a e in e ela ed and depend on he amoun o ille . By compa ing he di e en amoun s o di e en ypes o elec ically conduc i e ille s and hei in luence on he physically mechanical and elec ically conduc i e p ope ies, no one has s udy i so a and i is a ela i ely neglec ed opic. In cons uc ion, hese ma e ials a e becoming key elemen s o moni o ing he deg ada ion o building s uc u es, shielding s ay cu en s om elec i ica ion ne wo ks, shielding elec omagne ic adia ion in hospi al ooms, ca hodic p o ec ion agains mois u e, o e ol age p o ec ion o buildings, esis ance-hea ed conc e e o signal shielding o p ison acili ies [1]. 2. Ma e ials To e i y he e ec o he amoun o g aphi e on he elec ically conduc i e and mechanical p ope ies o he composi e we e designed composi es consis ing only o cemen and g aphi e we e c ea ed o elimina e he nega i e e ec s o any elec ically non-conduc i e ille s used. Fou ypes o indus ially p oduced g aphi e we e used as conduc i e ille , ep esen ing na u al and syn he ic g aphi es, coa se and ine ac ions and one wi h imp o ed elec oconduc i e p ope ies by su ace ea men (g aphi e C). The mos impo an pa ame e s o he g aphi es used a e lis ed in Table 1. Table 1. P ope ies o used elec ically conduc i e ille s. G aphi e Genesis Pa icle ype Speci ic su ace [m²/Kg] Impedance [Ω] A Na u al Fla lakes 1087 0.98 B Na u al I egula lakes 12187 1,45 C Na u al I egula wi h adjus men 19879 0.93 D Syn he ic I egula 12499 1.19 Po land cemen CEM I 42.5 R acco ding o EN 197-1 was used as a binde o he silica e composi e. I is a commonly used cemen wi h a designa ion wi h a as e inc ease in s eng h han o dina y cemen o a simila class. The basic p ope ies o CEM I 42.5 R cemen acco ding o he manu ac u e a e summa ized in Table 2. Young Scien is 2021 IOP Con . Se ies: Ma e ials Science and Enginee ing 1209 (2021) 012035 IOP Publishing doi:10.1088/1757-899X/1209/1/012035 3 Table 2. P ope ies o cemen . Type Densi y [kg/m2] Speci ic su ace [m²/kg] Impedance [Ω] Cemen CEM I 42,5 R 3110 391 7.66·106 G aphi e was dosed in o he composi e by weigh , in p opo ions o 4,7,10 and 13% by weigh o cemen . These alues we e chosen delibe a ely on he basis o expe ience om p o essional publica ions [1], whe e hey s a e ha he pe cola ion h eshold o g aphi es is abou 10% by weigh . Consequen ly, highe doses o g aphi e han he pe cola ion h eshold would no be e ec i e. Cemen and wa e we e also dosed by weigh . The wa e coe icien wc = 0.35 was used. The composi ion o he mix u es is gi en in he ollowing able. The p ope ies we e e i ied o each ype and dose o g aphi e on 9 es samples, in o al he p ope ies we e e i ied on 144 samples. Table 3. Composi ion o he mix u e. Designa ion o he mix u e Cemen (%) G aphi e (A, B, C, D %) A 4 96 4 A 7 93 7 A 10 90 10 A 13 87 13 B 4 96 4 B 7 93 7 B 10 90 10 B 13 87 13 C 4 96 4 C 7 93 7 C 10 90 10 C 13 87 13 D 4 96 4 D 7 93 7 D 10 90 10 D 13 87 13 3. Me hods Impo an pa ame e s we e de e mined on all inpu aw ma e ials, which we e he impedance de e mining he conduc i i y o he aw ma e ials and he speci ic su ace a ea, which indica es he g ain size and cha ac e o he pa icles. Fu he mo e, he shape o he g ains was speci ied using an elec on mic oscope. The speci ic su ace a ea o he elec ically conduc i e ille s and cemen s used was de e mined using BET me hods acco ding o ISO 9277: 1995 (E) [6]. The impedance o aw ma e ials and o med composi es was de e mined using a GW Ins ek LCR- 6020 measu ing de ice a a ol age o 1.0 kHz. The impedance o he aw ma e ials like g aphi e and cemen was measu ed using a mould wi h elec odes p in ed on a 3D p in e , which is shown in Figu e 1. The impedance o he composi es was de e mined on samples o 40x40x160 mm, which is shown in Figu e 2, in which coppe elec odes a e buil in. Figu e 3 a a dis ance o 120 mm. The cou se o measu ing he impedance o composi es is shown in Figu e 4. Impedance measu emen Figu e 4 he de ice is connec ed di ec ly o he elec odes o he composi e. Young Scien is 2021 IOP Con . Se ies: Ma e ials Science and Enginee ing 1209 (2021) 012035 IOP Publishing doi:10.1088/1757-899X/1209/1/012035 4 Figu e 1. Measu ing de ice GW Ins ek LCR- 6020. Figu e 2. Composi e es specimen o impedance measu emen . Figu e 3. Elec ode. Figu e 4. Impedance measu emen . The physical and mechanical p ope ies o he composi es we e de e mined a e 28 days o ma u a ion in a s anda d en i onmen on es specimens 40x40x160 mm. The lexu al ensile s eng h was de e mined on he samples using h ee-poin bending, acco ding o ČSN EN 12390-5. Comp essi e ensile s eng h was de e mined on ac ions o samples om he de e mina ion o lexu al ensile s eng h in acco dance wi h ČSN EN 12390-3 [7]. Young Scien is 2021 IOP Con . Se ies: Ma e ials Science and Enginee ing 1209 (2021) 012035 IOP Publishing doi:10.1088/1757-899X/1209/1/012035 5 4. Resul s The esul s o impedance measu emen s and de e mina ion o comp essi e s eng h and lexu al ensile s eng h a e 28 days o composi es wi h di e en amoun s and ypes o g aphi e a e e alua ed in Figu e 5, Figu e 6 and Figu e 7. Figu e 5. In luence o g aphi e amoun on impedance o composi e. Figu e 6. In luence o g aphi e amoun on comp essi e s eng h o composi es. Young Scien is 2021 IOP Con . Se ies: Ma e ials Science and Enginee ing 1209 (2021) 012035 IOP Publishing doi:10.1088/1757-899X/1209/1/012035 6 Figu e 7. In luence o he amoun o g aphi e on he ensile s eng h in bending o composi es. Wi h he addi ion o g aphi e o he composi e, i s impedance dec eases signi ican ly. The highes dec ease was eco ded a a dose o 13% by weigh , bu acco ding o he end, he pe cola ion h eshold, which is gi en a ound 10% by weigh , p obably did no be eached. Impedance was educed a doses o 4/7/10 and 13% by an a e age o 8/22/47 and 65%. The physical and mechanical p ope ies a e also a ec ed by he addi ion o g aphi e o he composi ion, he lexu al ensile s eng h has been imp o ed using coa se g aphi e ype (g aphi e A) and (g aphi e D) wi h medium g ain size and i egula olume ype, his imp o emen being ela i ely a ec ed by compac ion. In he case o comp essi e s eng h, a signi ican dec ease was eco ded al eady wi h he addi ion o 4% g aphi e, when he s eng h in he i s dec eased by 30%. A a dose o 7% he comp essi e s eng h dec eased by 38%, a 10% g aphi e he s eng h dec eased by 42% and a a dose o 13% g aphi e he comp essi e s eng h dec eased by 50%. F om he abo e esul s, wi h he addi ion o g aphi e o composi e, mainly a ec s he impedance and comp essi e s eng h o he composi e, hese alues dec ease om a long- e m poin in p opo ion o he inc easing dose o ille . 5. Conclusion The aim o his pape was o moni o he elec oconduc i e and physical-mechanical p ope ies and hei in e ac ions in silica e composi es wi h a ca bon-based ille . Va ious doses and ypes o g aphi e we e es ed and a he same ime he impedance, comp essi e s eng h and lexu al ensile s eng h o composi es we e moni o ed. By in oducing sui able ypes o g aphi e in o he silica e composi e, i s elec ically conduc i e, physical, and mechanical p ope ies can be signi ican ly in luenced. G aphi e as a ille is an e ec i e ma e ial o educe impedance. A a dose o 10% g aphi e he impedance is educed by 50%, wi h he comp essi e s eng h dec easing by abou 40%. The alues o hese p ope ies dec ease symme ically acco ding o ends wi h each added pe cen age o ille . The lexu al ensile s eng h is mainly a ec ed by he g ain size o he ille , wi h coa se ypes o lake- ype g aphi e ha ing a highe abili y o ansmi o ces in he ma e ial, while ine g aphi e ypes educe he lexu al ensile s eng h. Young Scien is 2021 IOP Con . Se ies: Ma e ials Science and Enginee ing 1209 (2021) 012035 IOP Publishing doi:10.1088/1757-899X/1209/1/012035 7 Syn he ic g aphi e and g aphi es wi h i egula and e y ine pa icles ha e been shown o be mo e e ec i e in achie ing lowe impedance alues. This is due o he la ge speci ic su ace a ea o he pa icles, and hus he highe p obabili y o con ac o i egula g ain su aces in he composi e ma ix. The di e en impedance o he g aphi es hemsel es as he aw ma e ial does no a ec he impedance o he en i e composi e. I can be said ha he impedance o he composi e depends mainly on he sui abili y o he size, shape o he pa icles and he e ec i e amoun o he conduc i e ille used in composi e. 6. Re e ences [1] Wu J, Liu J and Yang F 2015 Th ee-phase composi e conduc i e conc e e o pa emen deicing Cons uc ion and Building Ma e ials 75 129–135 (Ams e dam: No h-Holland/Ame ican Else ie ) [2] Te ashi a K, Tanaka T, Nishimu a K and Miyanami K 1993 Con inuous kneading o elec ically conduc i e composi e ma e ials and e alua ion o ille dispe sion s a e Bulle in o he Uni e si y o Osaka P e ec u e, Se ies (An Enginee ing and Na u al Sciences ol 421) pp 51– 67 [3] Rhee I, Lee J S, Kim Y A, Kim J H and Kim J H 2016 Elec ically conduc i e cemen mo a : Inco po a ing ice husk-de i ed high-su ace-a ea g aphene: Inco po a ing ice husk-de i ed high-su ace-a ea g aphene Cons uc ion and Building Ma e ials 125 632–42 [4] Xie P, Gu Ping and Beaudoin J J 1996 Elec ical pe cola ion phenomena in cemen composi es con aining conduc i e ib es Jou nal o Ma e ials Science 31 15 4093–97 [5] Kim G M, Pa k S M, Ryu G U and Lee H K 2017 Elec ical cha ac e is ics o hie a chical conduc i e pa hways in cemen i ious composi es inco po a ing CNT and ca bon ibe Conc e e Composi es 82 165–75 [6] ISO 9277:1995(E) De e mina ion o he speci ic su ace a ea o solids by gas adso p ion using he BET me hod [7] ČSN EN 12390-5 2020 Tes ing ha dened conc e e – Pa 5: Flexu al s eng h o es specimens [8] ČSN EN 12390-3 2019 Tes ing ha dened conc e e - Pa 3: Comp essi e s eng h o es specimens Acknowledgmen s The epo ed s udy was unded by RFBR acco ding o he p ojec № 19-53-26011, and speci ic esea ch p ojec № FAST-J-21-7491 „S udy o he s uc u e o elec ically conduc i e silica e composi es con aining ca bon-based ille s“.