Processing solid wood into a composite phase change material for thermal energy storage by introducing silica-stabilized polyethylene glycol

In this work, a composite phase change material was prepared by introducing silica-stabilized polyethylene glycol (PEG) into the porous structure of solid wood by temperature-assisted sol-gel method. Thermal properties, moisture adsorption and dimensional stability of the modified wood were tested and analyzed with help of morphology and structure characterization. The results show that SiO2 network is formed in modified wood and the modifiers distribute in both wood cell wall and cell lumen. This composite material exhibits considerable heat storage capacity and superior dimensional stability. Thermal cycling test shows the satisfactory thermal reliability of SiO2/PEG modified wood, suggesting the effective hindrance of SiO2 network on liquid phase leakage of PEG during phase transition. All above indicates that such modified wood could be potentially utilized as building material for energy conservation.