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

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-1at 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 ≈1012Ω · 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.

Modification of the three-dimensional graphene aerogel self-assembled network using a titanate coupling agent and its thermal conductivity mechanism with epoxy composites.

Three-dimensional thermally conductive graphene aerogels have become more and more significant in practical thermal management applications. However, the interface between the graphene aerogel and the polymer has a strong interface thermal resistance, and the compatibility between the interfaces is also poor. In this study, a simple and versatile method for grafting graphene aerogels with titanate coupling agents on the surface was developed so that the modified graphene aerogels exhibit excellent thermal conductivity and mechanical properties and reduce the interface thermal resistance and increase the interface compatibility between graphene aerogels and epoxy resin. A high thermal conductivity of 2.53 W m-1 K-1 was obtained under a low graphene load of 2.5 wt%, corresponding to a thermal conductivity enhancement of approximately 1388% compared with pure epoxy resin. It provides a facile new idea for the preparation of high-quality three-dimensional graphene epoxy composites.