Vertically aligned silicon carbide nanowires/reduced graphene oxide networks for enhancing the thermal conductivity of silicone rubber composites

Abstract

Ice-templated assembly strategy is an effective method to construct filler networks. The filler networks can be used to increase the thermal conductivity of polymer composites. Herein, silicon carbide nanowires, reduced graphene oxide and cellulose nanofiber were used as assembly units to construct vertically aligned filler networks by ice-templated assembly strategy. Polydimethylsiloxane grafted with poly(ethylene glycol) could enhance the interfacial interaction and improve the wettability between silicone rubber and the filler networks. Silicon carbide/reduced graphene oxide/silicone rubber composites were prepared by infiltrating the filler networks with silicone rubber. The thermal conductivity of the composites increased with increasing the contents of silicon carbide and reduced graphene oxide. The thermal conductivity of the composite with 1.84 vol% filler network was as high as 2.74 W/(m·K), exhibiting significant enhancement of thermal conductivity of 16 times compared with silicone rubber. This work provides an insight for preparing highly thermally conductive silicone rubber composites.