Phase change mediated graphene hydrogel-based thermal interface material with low thermal contact resistance for thermal management

Thermal interface materials (TIMs) are the key to solving heat dissipation problems in high-power electrical equipment. TIMs with high thermal conductivity and low thermal contact resistance (TCR) will enhance interfacial heat transfer. In this work, a phase-change mediated graphene composite hydrogel with low TCR and high thermal conductivity is designed. In addition, by introducing the hydrogel cross-linked network into the phase change material, the phase change material leakage problem is effectively solved. The thermal conductivity of the phase change hydrogel is enhanced by 324% from 0.3 Wm−1K−1 to 1.23 Wm−1K−1 at a filling rate of 7 wt% of graphene. The effects of temperature and pressure on phase change composite hydrogels are investigated. When the temperature is increased from 50 °C to 80 °C, TCR decreases rapidly from 90 K∙cm2/W to 0.2–0.5 K∙cm2/W, which is attributed to the improved interfacial wettability mediated by the phase change. When the pressure is increased from 10 Psi to 50 Psi with 80 °C, TCR decrease from 20 K∙cm2/W to 0.5 K∙cm2/W, improving interfacial contact and enhancing interfacial heat transfer. Combining a hydrogel with a cross-linked structure with the phase change material resulted in an excellent encapsulation of the phase change material. The thermal management performance of the phase change hydrogel is evaluated using infrared thermography and shows good thermal response behavior as the temperature rose to 68.7 °C after 120 s of heating. The strategy of combining phase change materials with hydrogels will provide new ideas for the design of TIMs.