Bio-composite bacterial cellulose/melamine foam to prepare advanced phase change materials with sandwich structures for thermal storage and energy conversion

Flexible composite phase change materials (FCPCMs) with superior encapsulation capability and high thermal storage density are attracting increasing interests in thermal management and application. Herein, we developed a new type of FCPCMs with unique structure and excellent comprehensive performance, obtained by introducing polyethylene glycol (PEG) into the sandwich-shaped composite foams (SCFs), which were constructed by biocompositing bacterial cellulose (BC) and melamine foam (MF). Features such as morphology, specific surface area, flexibility and heat storage capacity of the manufactured FCPCMs were investigated. As a consequence, the SCFs assembled by BC and MF possessed multi-porous structure combined with strong leakage resistance. Following vacuum impregnation with PEG, FCPCMs were fabricated with energy storage density in excess of 0.997. Even after 100 thermal cycles, the composites still retained superb thermal stability. Additionally, they also offered good photo-thermal conversion ability, meanwhile providing a high degree of temperature regulation. Due to their superior heat storage and solar energy conversion capability as well as biocompatibility, the FCPCMs exhibited enormous potential in the design and development of human thermal therapy materials.