Suppressed dielectric loss and enhanced thermal conductivity in poly(vinylidene fluoride) nanocomposites using polyethylene glycol-grafted graphene oxide

In order to realize efficient electronic energy storage and transfer, low dielectric loss as well as high thermal conductivity can be highly desirable for dielectric materials due to the associated ability to reduce and release the electrical energy dissipation as heat. However, it is challenging for percolative dielectric composites to simultaneously realize the two objectives above. In this study, polyethylene glycol-grafted graphene oxide (PEG-g-GO) is synthesized by grafting PEG on the graphene oxide. The grafted PEG serves as an interfacial modifier and insulting layer in poly(vinylidene fluoride) (PVDF)/GO system. The PVDF/PEG-g-GO composites simultaneously exhibit both lower dielectric loss and higher thermal conductivity than the PVDF/GO composites. The grafted PEG on the GO surfaces can inhibit the dielectric loss through increasing the insulation capacity and free volume, as well as enhance the thermal conductivity by promoting the interfacial interaction and the GO dispersion.