Ag-Deposited Pitch-Based Carbon Fiber/Silicone Composites With Enhanced Thermal Conductivity Through Reducing Interfacial Thermal Resistance

Thermal interface materials are crucial for the thermal management of modern electronic devices. The thermal conductivity of polymer-based composites, as the widely used thermal interface materials, is still limited by the high interfacial thermal resistance between the polymer matrix and the filler. Herein, pitch-based carbon fibers co-modified with silane coupling agent and Ag nanoparticles were developed and used as thermally conductive fillers to prepare silicone composites with the purpose of improving interfacial compatibility and reducing interfacial thermal resistance. Under scanning electron microscope observation, the modified carbon fibers dispersed uniformly, and they were adhered to by a number of Ag nanoparticles. The thermal conductivity of the silicone composite with a 20 wt% filling amount of modified carbon fibers reached up to 1.624 W m −1 K −1 , which was 1.46 times higher than that of the unmodified carbon fiber filled silicone composite. The silicone composite with a 20 wt% filling amount of modified carbon fibers also exhibited a relatively high heat transfer rate and excellent mechanical properties. The electrical insulation and dielectric properties of silicone composites filled with modified carbon fibers also satisfied the requirements for the use of thermal interface materials. This approach provided an effective strategy for the development of thermal interface materials with high thermal conductivity in the thermal management field.