Modification of ionic wood for enhanced phase change performance

Abstract

Abstract Wood with a porous structure is the best carrier for phase change energy storage materials, which can effectively prevent material leakage during thermal cycling and ensure its shaping effect. In this work, the delignified veneer oxidized with TEMPO was used as a thermal energy storage system. Then, it was immersed in a solution of ethanol as the solvent, polyethylene glycol (PEG), and calcium chloride as the solutes, obtaining thermal energy storage ionic wood (DTW-TES). The results showed that the phase change material PEG2000-CaCl2 was impregnated into the pore structure of wood; calcium ions were effectively combined with -COOH in modified wood for intermediate bonds, thus forming white complex crystals with PEG2000. As a result, PEG2000-CaCl2 was successfully adsorbed into wood pores. The maximum absorption rate and differential scanning calorimetry (DSC) test results showed that TEMPO-oxidized delignified poplar had a maximum absorption rate of 99% for PEG2000-CaCl2. Additionally, TEMPO-oxidized delignified poplar exhibited good phase transition performance and a suitable phase transition temperature of 23.2oC. The latent heat of phase transition was 84.8 J/g. Thus, the novel DTW-TES displayed a high potential application in the field of thermal energy storage and temperature regulation.