Effect of temperature and oxygen functional groups on interaction between epoxy resins and graphene surface

Abstract

Surface interactions between epoxy matrices and graphene nanosheets can directly affect the properties of nanocomposites, and such interactions are crucial to investigate. In this study, molecular dynamics simulation was used to investigate the interaction rate between epoxy thermoset resins (EPON 828, EPON 862, Epoxy Novolac, and Cycloaliphatic Epoxy) with graphene, and Functionalized Graphene with Oxygen Functional Groups. The effect of temperatures and different weight percentage of graphene oxide (1, 3, and 5 wt.%) was studied, and as a result of which it was observed that increasing the weight percentage of graphene oxide improved the interaction energy (adhesion) between epoxy resins and graphene oxide. Also, it decreased the radius of gyration (more contraction of epoxy molecules than graphene oxide nanosheets). In addition, increasing the temperature led to reduction of the interaction energy between epoxy resins and functionalized graphene. Moreover, escalating the temperature did not have any significant effect on the radius of gyration and Epoxy molecules resizing compared to graphene oxide nanosheets. The amount of interaction energy between epoxy resins and pristine graphene is very low in comparison with graphene oxide; therefore, temperature has a small effect on the amount of interaction energy and radius of gyration. Finally, the strongest interaction energy was found to be related to Epoxy Novolac and EPON 862 resins by comparing the interaction energy and radius of gyration between epoxy resins with graphene oxide. Therefore, they were the best candidates for matrixes in epoxy/graphene oxide nanocomposites.