Influence of oxidized graphene nanoplatelets and [DMIM][NTf2] ionic liquid on the tribological performance of an epoxy-PTFE coating

This work reports the tribological performance of a self-lubricating epoxy-PTFE coating modified with oxidized graphene nanoplatelets (GNPox) and 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [DMIM][NTf2] ionic liquid, alone and in combination. [DMIM][NTf2] was incorporated without encapsulation, which is shown not to hinder coating adhesion for the tested applications. Crossed-cylinders tribological testing of coatings under different load conditions showed synergistic effects from the combination of GNPox and ionic liquid. The ionic liquid introduced a plasticizing effect on the binder, increasing the actual contact area and facilitating boundary-lubrication. The boundary-lubrication regime facilitated GNPox particle orientation and reduction of their abrasive behaviour, contributing to a lowered coefficient of friction.