Naslov
Computational approach for electrical conductivity of geopolymer-graphite composites

Autori
Zhang, Shifan ; Ukrainczyk, Neven ; Rukavina, Marko ; Mandić, Vilko ; Koenders, Eddie

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
1st ACDC 2023 BOOK of ABSTRACTS / Mandić, Vilko - Zagreb, 2023, 24-24

Skup
1st International Conference of the Croatian Ceramic Society (CroCerS): Advanced Ceramics in Derivative Configurations (1st ACDC 2023)

Mjesto i datum
Dubrovnik, Hrvatska, 26.04.2023. - 29.04.2023

Vrsta sudjelovanja
Radionica

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
geopolymers ; graphite ; electrical conductivity ; particle models ; percolation ; effective medium theory

Sažetak
This invited workshop talk delves into the effective conductivity of geopolymer-graphite composites using mathematical modeling techniques. To simulate the percolation threshold, a particle- based Monte Carlo method is employed to generate virtual composite microstructures and simulate percolation phenomena. The effective medium model is then utilized to model the conductivity of the composite. The percolation and effective conductivity of a multi-phase mixture is closely related to the physicochemical characteristics of the mixed phases, such as the porosity and particle size distribution of individual components (metakaolin, graphite, and air) embedded in the geopolymer gel matrix. To investigate the effect of particle size distribution of the mixture phase on the percolation threshold, Hymostruc is used to generate a three-dimensional model of a mixture, which is then analyzed for connectivity of the conductive (graphite) filler using Matlab. The results indicate that the percolation threshold of a three-phase mixture of metakaolin, graphite, and pore is affected by the addition of segregated third phase, namely metakaolin or air (particle). To study the effect of metakaolin and porosity on the percolation threshold, the concept of effective volume fraction is introduced. This is defined as the ratio of the volume fraction of graphite to the total solid volume after excluding the segregated volume. Finally, a simple analytical effective medium model proposed by Bruggeman is used to simulate the variation pattern of conductivity of the mixture with increasing graphite content, in combination with the percolation threshold of the system simulated by Monte Carlo method. The simulation results show good agreement with the measurement results

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija, Interdisciplinarne prirodne znanosti, Građevinarstvo, Interdisciplinarne tehničke znanosti

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