Effects of graphene surface energy on the structure and mechanical properties of phenolic foams

Abstract

AbstractGraphene nanoplates (GNPs) and graphene oxide (GO) were used to investigate the effects of surface free energy (SFE) of nanoparticles on the cellular structure and mechanical properties of phenolic nanocomposite foams. The results showed that the SFE of nanoparticles is a key parameter in determining the interfacial action between fillers and matrix before foaming, which in turn determines the energy barrier of bubble nucleation during foaming process. It indicated that the higher interfacial energy of GO brought out the lower Gibbs free energy and smaller driving force for heterogeneous nucleation, leading to smaller cell size with more uniform distribution. According to the effect of SFE in foaming process, different mass fractions of GNPs and GO were used in phenolic foams to investigate the effects of heterogeneous nucleating agent on cell nucleation. As a result, phenolic foam with 0.6 wt% graphene oxide (GO-0.6/PF) exhibited the optimized mechanical properties and cell microstructure.