Form-stable paraffin/rice straw/polyvinyl alcohol composite phase change material for thermal energy storage

[Display omitted] •A new method to prepare composite PCM with rice straw as the support has been developed.•Paraffin is loaded on rice straw in the form of microparticles.•PVA coating can effectively prevent the leakage of paraffin.•The prepared composite PCM has high latent heat and excellent cycling stability. A form-stable phase change material (PCM) based on paraffin was prepared with rice straw as the supporting material. First, a paraffin miniemulsion was prepared by ultrasonication. Then, the paraffin was loaded on rice straw via a vacuum impregnation method. Finally, the paraffin particles loaded on the rice straw were coated by a polyvinyl alcohol (PVA) film. Scanning electron microscopy images confirm the successful loading of paraffin on rice straw and the coating of PVA on the paraffin particles. Differential scanning calorimetry measurements reveal that the prepared material has a high latent heat of 133.4 J/g. The leakage test verifies that the material has a good cycling stability with only 1.6% latent heat loss after 100 consecutive melting-freezing cycles. The prepared form-stable PCM is promising in thermal energy storage.