Novel fabrication of polyethylene glycol/ceramic composite pellets with an excellent phase change shape stable trait and their potential applications for greenhouse insulation

Abstract

Organic solid–liquid phase change materials (PCMs) face challenges in practical applications due to their susceptibility to leakage during phase transitions. To address this issue, we constructed the polyethylene glycol (PEG)/ceramic pellets (CPs) composite phase change shape stable materials (PCSHs) with thermal energy storage capability, thermal stability, and a firm texture using the melting impregnation method. The PCSHs exhibit remarkable shape stability in the leakage test due to the capillary action and surface tension generated by the micropore structure on their surface. They also can convert light energy into heat and store it as latent heat, achieving an optimal photothermal conversion efficiency of 45.21 % and a maximum melting enthalpy of 13.33 kJ/kg at a PEG loading of ∼ 12 %. An outdoor greenhouse insulation simulation experiment confirmed that the PCSHs can maintain soil temperatures above 30 °C for over 30 min after illumination ceases. This work presents a facile synthesis strategy for shape-stable PCMs with potential applications in greenhouse insulation.