Selective toughening of Carbon/Epoxy composites using graphene oxide

Abstract

Graphene oxide (GO) is an oxide form of graphite, which still preserves the parental layered structure terminated by oxygen rich groups like epoxide, carbonyl and hydroxyl. Its strong affinity for water attributes to its high dispersibility in it. The present work discusses the idea of incorporation of GO nano-particles into composites for improving the fracture toughness. Water soluble polymer, Polyvinyl pyrrollidone (PVP) is made use of to carry the nanoparticles into the interface. It is expected that the terminal groups in GO can react with epoxy and similar resin systems in the interlaminar region, while the base planes help in improving the mechanical properties. GO plates in the interface are expected to act as crack deflectors, laying down a torturous path for a propagating crack and increasing the energy required for delamination. Composite mechanical properties including fracture toughness and flexural modulus are measured. A 100 percent improvement in the fracture toughness with an addition of 5 weight percent of GO (w.r.t PVP) is obtained without trading away flexural modulus.