Preparation and mechanism research of bio-inspired dopamine decorated expanded graphite/silicone rubber composite with high thermal conductivity and excellent insulation

Abstract

Abstract This study looked at the process of designing and synthesized expanded graphite (EG) and modifying it with bio-inspired dopamine (DOPA). This is a process used to improve the thermal conductivity and dielectric properties of methyl vinyl silicone rubber (VMQ). The results demonstrated that the EG-DOPA-VMQ composites acquired an exceptional thermal conductivity of 1.015 W mK−1 at the loading of 10 wt%, approximately 480% higher than that of pure silicone rubber (0.175 W mK−1). This enhancement is mainly attributed to the improved dispersion capability of EG-DOPA and the robust interfacial interaction between EG-DOPA-VMQ interfaces; specifically, this is the result when compared with pristine EG. Moreover, throughout this process, the composites maintained an excellent insulating property with a resistance of ≈1012 Ω · cm; this particular result was due to the DOPA deposited on EG surfaces because they acted as an insulating layer, inhibiting the electron transfer in composites. Overall, this work demonstrated that it could present a promising strategy for synchronized manufacturing of polymer composites with high thermal conductivity and insulating capability.