Facile in-situ fabrication of latent heat enhanced cellulose aerogel-based form-stable composite phase change materials based on dopamine modification strategy

In this work, the latent heat enhanced polyethylene glycol (PEG)/cellulose aerogel (CA)-dopamine form-stable composite phase change materials (PCD fs-CPCMs) were constructed by facile in-situ fabrication method based on the freeze casting. Under the simultaneous synergistic effect of CA and dopamine modification, the PCD fs-CPCMs achieved ultra-high encapsulation capacity of ~95 wt% and latent heat of ~194.3 J/g. Furtherly, compared with before the dopamine modification, the latent heat of PCD fs-CPCMs was increased by ~18.9%, and the difference between theoretical and experimental value was significantly reduced, indicating that the modification effectively promoted phase change behavior and improved heat storage characteristic of PEG. The ultra-high encapsulation capacity was mainly attributed to the lightweight and porous characteristic of CA and the effective entanglement and combination of PEG molecular chain. The increased latent heat was mainly ascribed to the construction of new combination approaches among PEG, CA and dopamine, resulting in the weakening of hydrogen bond effect (before and after modification: O-H⋯O > O-H⋯N or N-H⋯O) so that the confinement effect of surfaces was weakened and modified surface-induced phase change behavior was promoted. Moreover, the PCD fs-CPCMs exhibited excellent chemical compatibility, reasonable heat storage and release rates, and acceptable thermal reliability and stability.