The effect of hydroxylated multi-walled carbon nanotubes on the properties of peg-cacl2 form-stable phase change materials

Abstract

Calcium ions can react with polyethylene glycol (PEG) to form a form-stable phase change material, but the low thermal conductivity hinders its practical application. In this paper, hy-droxylated multi-walled carbon nanotubes (MWCNTs) with different mass are introduced into PEG1500·CaCl2 form-stable phase change material to prepare a new type of energy storage material. Carbon nanotubes increased the mean free path (MFP) of phonons and effectively reduced the interfacial thermal resistance between pure PEG and PEG1500·CaCl2 3D skeleton structure. Thermal conductivity was significant improved after increasing MWCNTs mass, while the latent heat decreases. At 1.5 wt%, composite material shows the highest phase change temperature of 42◦ C, and its thermal conductivity is 291.30% higher than pure PEG1500·CaCl2 . This article can provide some suggestions for the preparation and application of high thermal conductivity form-stable phase change materials.