Preparation of a graphene–silver nanowire hybrid/silicone rubber composite for thermal interface materials

Abstract In this study, we used acrylamide-modified reduced graphene oxide (AA-RGO) and thiophenol modified silver nanowires (mAgNWs) as reinforcements, and silicone rubber (SR) as a polymer matrix. One-dimensional mAgNWs and two-dimensional RGO can form synergetic effects and construct a three-dimensional network structure for thermal conduction in SR to improve the thermal conductivity of SR composites. SEM images showed a few aggregations of AA-RGO at 6 and 10 phr. However, the thermal conductivity of composites with some aggregations can be significantly higher than that of dispersed homogeneous composites. An interconnected hybrid network between AA-RGO and mAgNWs appears to have been caused by a π – π interaction. The thermal conductivity of mAgNW/AA-RGO/SR nanocomposites (approximately 1.152 W/mK) were higher than those of AA-RGO/SR composites without mAgNWs (approximately 0.412 W/mK), and considerably higher than those of neat SR (0.180 W/mK). Furthermore, the coefficient of thermal expansion (CTE) of the mAgNW/AA-RGO/SR nanocomposites were 148.3 ppm/°C, which differs considerably from the CTE of neat SR, 310.0 ppm/°C. Therefore, AA-RGO–mAgNWs hybrid/SR composites are promising carbon materials for thermal interface materials.