Shape-stabilized nanosilver-modified grapefruit peel-based porous carbon composite phase change material with high thermal conductivity, photothermal conversion performance and thermal management capability

Polyethylene glycol (PEG) is greatly limited in the fields of phase change heat storing and solar energy absorption due to its low thermal conductivity , poor thermal stability and weak photo-thermal effect. Aiming at solving the above concerns, this work structures a new composite phase change material (PCM)(PEG/BPC@Ag) with biomass grapefruit peel-based porous carbon foam (BPC) as the backbone material and Nano-Ag as a surface-modified component, and the phase change medium PEG by simple vacuum immersion method. The test findings revealed that the modified carbon foam with Nano-Ag has excellent three-dimensional structure and photo-thermal effect, which makes the prepared composite PCM(CPCM) have enhanced photo-thermal transformation capacity, an enhanced thermal conductivity and excellent thermal stability. Among them, the thermic conductivity of the PEG/BPC@Ag was increased by 2.1 folds to 0.68 W/Mk. similarly, its enthalpy efficiency λ and was increased from 82.0 % to 83.7 %, and the photo-thermal transformation performance θ was increased from 76.8 % to 91.2 %. As well, the PEG/BPC@Ag has exceptional reusability and thermic robustness performance. Comprehensively, the PEG/BPC@Ag prepared in this work has a wide potential for application both in waste heat recovery and solar energy absorption, as well as in thermal management of electronic components, as well as providing a feasible solution for solid waste recycling in utilization.