High Thermal Conductivity and Mechanical Strength Phase Change Composite with Double Supporting Skeletons for Industrial Waste Heat Recovery

The "solid-liquid" leakage and low thermal conductivity of organic phase change materials limit their wide range of applications. In this paper, a novel carbon fiber/boron nitride (CF/BN)-based nested structure was constructed, and then, a series of poly(ethylene glycol) (PEG)-based phase change composites (PCCs) with high thermal conductivity and mechanical strength were prepared via the simple vacuum adsorption technology by employing the CF/BN nested structure as the heat conduction path and supporting material and the in situ obtained cross-linking epoxy resin as another supporting material. The thermal conductivity of the obtained PCC is as high as 0.81 W/m K, which is 7.4 times higher than that sample without the CF/BN nested structure. The support of the double skeletons confers the obtained PCCs with excellent mechanical strength. Surprisingly, there is not any deformation for PCCs under the pressure of 128.5 times its own weight during the phase change process. In addition, the phase change enthalpy of the obtained PCC is as high as 107.9 J/g. All the results indicate that the obtained PEG-based PCCs possess huge application potential in the field of industrial waste heat recovery.