Assessing graphene oxide/polymer interfacial interactions by way of peeling test

The design of graphene/polymer nanocomposites with improved mechanical properties requires characterization of the interfacial interactions between different types of graphene sheets and different polymers. In this study, the interactions in a graphene oxide (GO)/polymer nanocomposite were explored and the effect of thermal reduction of GO on adhesion was tested. A versatile peeling test was demonstrated and applied on a wide range of nanosheet fillers and polymers, which has great potential for expedited development of enhanced nanocomposites. The interactions of GO and reduced graphene oxide (rGO) nanofillers were tested with widely used polymers, including poly(methyl methacrylate), polystyrene, acrylic, polyvinyl alcohol, polyetherimide and polyimide. The results show the effect of thermal reduction of GO on the interactions in polymer nanocomposites and rank the interfacial preferences of GO and rGO for different polymers. In terms of surface energy considerations, some of the results are in agreement with expectations, others are in direct contradiction. This discrepancy suggests that molecular-level effects, which are not reflected in the macroscopic material properties, play a significant role.