Graphene nanoparticle dispersion in epoxy thin film composites for electronic applications: effect on tensile, electrical and thermal properties

Graphene nanopowder (GNP)/epoxy thin film composites were fabricated using an ultrasonication and spin-coating technique. This study aims to investigate the effect of dispersion state and filler loading (0.025–1 vol%) of GNP on the tensile, electrical and thermal properties of the GNP/epoxy composites. GNP/epoxy composites with different dispersion states were prepared, and a combination of sonication and chloroform (as the dispersion solution) was used in one of the samples. The addition of GNP decreased the tensile properties of the epoxy composites. However, among the tested samples, the chloroform GNP (ch-GNP)/epoxy composites had higher tensile properties, especially at low filler loading (0.05–0.2 vol%). Although the ch-GNP/epoxy formed clusters, a higher degree of dispersion and exfoliation of GNP was observed in each cluster, due to improve dispersion by chloroform compared to the system without chloroform. The rolling of GNP was found to be dominant in the ch-GNP/epoxy composite. Electrical properties showed that the ch-GNP/epoxy composites exhibit higher electrical conductivity with lower percolation thresholds value than that the GNP/epoxy composites. From the thermal properties it was determined that composites with the dispersion solution showed a higher glass transition temperature (T_g) than those without the dispersion solution.