In situ preparation of light-driven cellulose-Mxene aerogels based composite phase change materials with simultaneously enhanced light-to-heat conversion, heat transfer and heat storage

The latent heats of form-stable composite phase change materials (fs-CPCMs) were usually reduced while synergistically improving their heat transfer and light-to-heat conversion properties. In this work, the polyethylene glycol/MXene-cellulose aerogels (PMC) fs-CPCMs with simultaneously enhanced light-to-heat conversion, heat transfer and heat storage were prepared by one-step in situ encapsulation method based on freezing casting. The light-to-heat conversion efficiency of PMC fs-CPCMs achieved ~ 91.6% due to the fact that the MXene acted as an effective photon captor and molecular heater under solar irradiation. The heat transfer of PMC fs-CPCMs was effectively improved by dispersed MXene due to the formation of heat conduction network or path. Importantly, the latent heats of PMC fs-CPCMs (about 183 J/g) were not reduced, because 90 wt% PEG was encapsulated in situ during the formation of pore structures of cellulose-Mxene aerogels under freezing casting. Moreover, the PMC fs-CPCMs showed excellent chemical compatibility and acceptable thermal stability.