Surface growth of MG(multilayer graphene)–SiC nanofillers/poly(vinylidene fluoride) composites for improving thermal conductivity and maintaining electrical insulation

In the present research, a high-frequency heating process with the advantages of simplicity and high yield was applied to synthesize multilayer graphene–SiC nanofillers (MG–SiC_nf) and found to boost yields dramatically. The growth process of MG–SiC_nf was also investigated. Nanofillers grown on an MG surface consisted of both SiC particles and SiC nanofibers. Interestingly, the growth process of SiC nanofibers included two main steps: firstly, SiC particles gathered on the edge of the MG, and then they grew into SiC nanofibers. SiC nanofibers enhanced the thermal conductivity of materials whereas SiC particles tended to hinder electronic transmission. The vertical and in-plane orientated thermal conductivities of poly(vinylidene fluoride) (PVDF)/MG–SiC_nf composites were determined to be 0.28 and 30.491 W m⁻¹ K⁻¹, while the maximum value of the electrical conductivity of PVDF/MG–SiC_nf composites was only 2.0  ×  10⁻¹¹ S cm⁻¹. In addition, the storage modulus of PVDF/MG–SiC_nf composites also improved remarkably in comparison with that of pure PVDF. (paper)