Fluorine-terminated functionalized liquid metal/silicon carbide binary nanoparticles for polyvinyl alcohol composite films with high in-plane thermal conductivity and ultra-low dielectric constant

Highly thermally conductive and low dielectric constant are among the most sought-after properties of flexible polymer-based thermal-management materials (TMMs). However, it remains a formidable challenge to develop efficient thermal dissipation materials with fascinating comprehensive performance. In this work, we present an interfacial engineering strategy using trifluoropropyltriethoxysilane (TFPTES) to act as a thermal linker at granular silicon carbide-liquid metal (SiC-LM) binary interfaces (SiC-LM@F) in the polyvinyl alcohol (PVA) matrix, in which the LMs merely partially anchored to the surface of binary filler by a controllable ball milling technology. The strong hydrogen bonding and/or compact “shoulder-to-shoulder” contact between the binary components and matrix interfaces confer an expressway for the propagation of interfacial phonons. For this, the developed PVA/SiC-LM@F composite film demonstrates a high in-plane TC of 10.2 W m−1 K−1 and ultra-low dielectric constant of 1.49 at 106 Hz at 40 wt% SiC-LM@F loading content, which is more superior to those of the other counterparts in this experiment. Additionally, the obtained PVA/SiC-LM@F composite film also reveals favorable tensile strength, excellent electric insulation, and efficient cooling capacity. This interfacial engineering strategy is expected to offer a versatile solution to the design and construction of advanced thermal-management materials (TMMs).