Silver nanoparticles decorated 3D reduced graphene oxides as hybrid filler for enhancing thermal conductivity of polystyrene composites

Polystyrene (PS) composites with silver nanoparticles (AgNPs)-decorated reduced graphene oxides (rGO) were prepared by electrostatic self -assembly and following a hot press process. Specifically, GO sheets were uniformly attached to positively charged PS microspheres through electrostatic absorption, and then, AgNPs were in situ reduced on the surface of PS/rGO composite microspheres. Followed by hot press, the sintering process of AgNPs induced bridge connection between the adjacent rGO sheets obviously, therefore, three dimensional (3D) rGO conductive frameworks featured by AgNPs adhesive was constructed in the composite. The synergistic effect of rGO and AgNPs in the frameworks contributed to significant enhancement of thermal conductivity. Thus, the thermal conductivity of the PS/rGO-AgNPs composite reached 0.54 W/(m K), about 2.38 times higher than that of pure PS material. This result suggests that AgNPs-decorated 3D rGO as a hybrid filler is an effective strategy for enhancing thermal conductive performance of polymer composites.