Improving Interfacial Adhesion of Graphite/Epoxy Composites by Surface Functionalization

Graphite/epoxy resin (G/EP) compositesare extensively utilizedin bipolar plates for fuel cells owing to their outstanding electricaland mechanical properties. However, the mechanical strength of thesecomposites declines notably due to the inadequate bonding interfacebetween graphite and epoxy resin. To address this issue, we used moleculardynamics (MD) simulations to study the influence of graphite surfacefunctionalization on the interfacial structures of composites. Theresults of this study revealed that the functionalization of the graphitesurface led to an increase in the interface thickness of the composite.This phenomenon can be attributed to the interdiffusion and hydrogenbond formation between functionalized graphite and epoxy molecularchains. And all four types of functional groups demonstrated a promotingeffect on the adsorption process. Additionally, the adsorption andcontact angle results provided further evidence that the adsorptionrate of graphite to the epoxy resin significantly improved afterfunctionalization. These findings contribute to a more comprehensiveunderstanding of the microscopic process of forming interfaces in G/EP composites. In addition, these insights provide valuable guidancefor improving the interface bonding of composite bipolar plates, whichcan ultimately increase their mechanical strength.