Effect of graphene nanoparticles on electrical, mechanical and viscoelastic behavior of <scp>CFRP</scp> multifunctional multiscale composites

Abstract The present work investigates effect of the incorporation of GNPs into epoxy matrix composites reinforced with CFs on their electrical, mechanical and viscoelastic properties. The GNP content in the composite were added as 0.1%, 0.2%, 0.3%, and 0.4% by weight. The study presents detailed analysis of conductivity mechanism revealing an 8‐fold increase in surface electrical conductivity at 0.4 wt% GNP content, reaching 2.32 S/m. The mechanical properties showed significant enhancement with the incorporation of GNPs up to 0.3 wt%, reaching a maximum tensile strength of 1008 MPa and peak flexural strength of 952 MPa, and the highest impact strength of 13 J/cm 2 . However, a decline in mechanical performance was observed at 0.4 wt% GNP content, primarily due to fiber‐matrix debonding. The DMA analysis further revealed an increase in the storage modulus and loss modulus at 0.1 wt% GNP content, reaching 10,099 and 1570 MPa, respectively. However, at higher GNP content, adverse effects on the composite's behavior were observed, attributed to uneven distribution and interactions of the GNPs. Highlights Impact of GNPs on the electrical and viscoelastic properties of CFRP analyzed. GNPs enhance surface electrical conductivity of CFRP composites at 0.4 wt%. GNPs improve viscoelastic properties of CFRP composites at 0.1 wt%. Suitable mechanisms illustrated, correlated with results and discussed.