Synergistic effect of hybrid carbon nantube-graphene oxide as a nanofiller in enhancing the mechanical properties of PVA composites

A poly(vinyl alcohol) (PVA) based nanocomposite using fully exfoliated graphene oxide (GO) sheets and multi-walled carbon nanotubes (CNTs) were prepared via a simple procedure. It is confirmed from optical imaging that dispersion of CNTs in the PVA matrix can be significantly improved by adding GO sheets. Molecular dynamics (MD) simulations suggest that the GO-CNT interaction is strong and the complex is thermodynamically favorable over agglomerates of CNTs. The GO-CNT scroll-like structure formed with the hydrophilic outer surface of GO can be well dispersed in water. More important, a synergistic effect arises from the combination of CNT and GO, the GO-CNT/PVA composite films show superior mechanical properties compared to PVA composite films enhanced by GO or CNT alone, not only the tensile strength and Young's modulus of the composites are significantly improved, but most of the ductility is also retained. The enhanced mechanical properties of the GO-CNT/PVA composite film can be attributed to the fully exploited reinforcement effect from GO and CNT via good dispersion.