Sol-Gel condensation of temperature sensitive and shape stabilized phase change materials for thermal energy storage

Shape-stable phase change materials (SSPCMs) with visible phase change progress are of great importance to thermal management. Herein, novel SSPCMs were facilely fabricated from 1,2,3-tris-(2,3-Epoxypropoxy) propane, polyethyleneimine (PEI) and poly(ethylene glycol) by sol-gel condensation. The resultant SSPCMs showed good shape stability at 70 degrees C, they were temperature sensitive at phase transition, where reversible transparent-opaque transfer for PEG content 45-65 %. Latent heats of the SSPCMs were almost proportional to the PEG content and the highest value reached 131.8 +/- 1.9 J/g at PEG content of 86 % (PE-86 %). The curing kinetics were analyzed by the Vyazovkin isoconversional method, the results indicated that the activation energy of PE-86 % was lower than that of pure PEG, suggesting that the supporting matrix had higher reactivity and could accelerate the reaction. Additionally, the SSPCMs also exhibited favorable thermal cycling reliability and thermal stability. The temperature sensitive and excellent thermal performance of the SSPCMs made them of great potential in thermal energy storage applications.