Polyethylene glycol/silica (PEG@SiO2) composite inspired by the synthesis of mesoporous materials as shape-stabilized phase change material for energy storage

Abstract Inspired by the common preparation method of mesoporous silica where polyethylene glycol (PEG) was used as template to obtain porous silica, PEG/silica (PEG@SiO 2 ) composite as shape-stabilized phase change material for energy storage was well prepared. In this paper, PEG was used as phase change material (PCM) to store and release thermal energy and SiO 2 acted as the supporting matrix. Various techniques were employed to characterize the structural and thermal properties of PEG@SiO 2 . The results indicate that PEG was encapsulated in SiO 2 shell with physical interactions. The phase change enthalpy of PEG@SiO 2 is 164.9 J/g in the melting process and 160.1 J/g in the solidifying process with the mass fraction of 97 wt%. It is a considerably exciting result as the value is so close to pristine PEG’s (178.6 J/g). PEG@SiO 2 exhibited excellent thermal reliability based on the results of undergoing the heating-cooling cycle 100 times. Also, PEG@SiO 2 had a good thermal stability within its working temperature range. This study provides a general approach for increasing the loading of PCMs in porous materials and thus the energy storage capability.