The effect of adding graphene oxide into CNT/polymer system on the CNT dispersion and mechanical properties of the hybrid nanocomposites

The influence of adding graphene oxide (GO) fillers into CNT nanocomposites on the formation of CNT agglomerates and on their synergistic effect to the mechanical properties are investigated in this paper. To this end, a two-scale homogenization scheme and a GO-dependent morphological model of CNT agglomeration are built to predict the effective elastic moduli and strain-hardening behaviors of the hybrid composite. We adopt the Mori-Tanaka method, self-consistent theory and field-fluctuation approach to derive the effective secant moduli and Mises stress of each phase in or outside CNT agglomerates. In addition, the interface effects, including imperfect mechanical bonding and interfacial tangential sliding between fillers and matrix, are also considered. The results show that the addition of GO significantly reduces the size and volume fraction of CNT agglomerates, leading to an enhanced dispersion of CNTs within the PVA matrix. The effective mechanical properties of the hybrid nanocomposites, including tensile strength and Young's modulus, are also improved. The combinatorial impact of GO and CNTs on the composites is found to be superior to one with either GO or CNTs alone. •Enhanced mechanical properties are simulated for GO/CNT/PVA nanocomposites that contain CNT agglomerates.•It proves the addition of GO can improve the dispersion of CNTs and decrease the CNT agglomerates inside composites.•Construct an inverse proportional model to describe the GO-dependent CNT agglomeration.•Elastoplastic behaviors, imperfect interface and tangential interface sliding effects are considered.•The results are validated with experiment data of GO/CNT/PVA and GNP/CNT/epoxy nanocomposites.