Microwaves Heating Strategy to Synthesize Few Layer Graphene for Polymer Composites towards Thermal and Electrical Applications

Abstract The few-layer graphene (FLG) with tailorable microstructure for macro-properties is prepared from graphene oxide (GO) by simple, fast and inside microwave (Mw) heating strategy. The effects of varying power, environment and time on FLG are studied throughout Mw treatment. The investigations based on microscopic and spectroscopic results confirm the formation of FLG having much less oxygen-containing functional group with an average layer thickness of ~1.378 nm. The parameters related to the excellence of graphene such as carbon/oxygen (C/O) and Id/Ig ratios are calculated approximately to be ~2.99 and ~0.43 respectively. In addition, thermal interface materials (TIMs) and electrodes are fabricated to check their efficiencies. The highest thermal conductivity of 0.25 W m−1 K−1 is achieved by adding just 1 wt% FLG, which is ~278% that of the fluoropolymer being used. In electrochemical impedance spectroscopy (EIS), the Mw treated GO shows the maximum charge transfer resistance of around 100 Ω, displaying almost 12 times lower than that of the pristine GO. Thermally reduced graphene oxide (rGO) at 1000 °C is also prepared for comparison and it is concluded that FLG by Mw treatment is significantly better than rGO for such kind of real-life applications.