Improved dispersion and interface in the graphene/epoxy composites via a facile surfactant-assisted process

Both the irreversible agglomeration of graphene sheets and poor sheet/matrix interface are obstacles to obtain the desired properties of graphene/polymer composites. Herein, we fabricated epoxy composites with highly dispersed graphene via a facile surfactant-assisted process, and investigated the correlations between surface modification, morphologies, dispersion, re-agglomeration behaviour and interfacial interaction of graphene and the corresponding thermal and mechanical properties of the composites. It is found that the surfactant treatments of graphene are effective to improve their dispersion stability in water and inhibit their re-agglomeration during the curing of resin. Scanning and transmission electron microscopy analysis demonstrates that the dispersion/exfoliation level of graphene in the composites is greatly improved after surface treatments. These above ameliorating effects along with improved interface between the matrix and graphene arising from the hydrophilic and hydrophobic molecules of non-ionic surfactant result in increased tensile properties compared with those without surface modification. Moreover, the thermal stability of the graphene/epoxy composites is slightly enhanced over that of neat epoxy.