Synthesis and characterization of a modified diatomite-based hybrid shell microcapsule for thermal energy storage

Abstract

In this paper, modified diatomite (MDE) was used for the moisture adjustment substrate, and lauryl-cetyl alcohol (LAL–CAL) was utilized as the phase change material (PCM) to synthesize MDE-based hybrid shell microcapsule PCMs (MDE-MPCMs) with humidity and temperature control functions through the sol–gel method. Fourier transform infrared spectroscopy was used to study the chemical compatibility between MDE and LAL–CAL. The effects of different MDE content for humidity regulation, heat storage, and surface temperature response behaviors of MDE-MPCMs were studied through humidity regulation experiments, differential scanning calorimetry, and infrared thermal imaging technology. The results showed that LAL–CAL was successfully coated within the hybrid shell structure, and the moisture absorption capacity and thermal stability of MPCM were enhanced after the introduction of MDE. When MDE content was 15%, the moisture absorption rate of MDE-MPCM3 reached 16.63%, and the corresponding latent heat value was 70.01 J g⁻¹. Those results demonstrated that MDE-MPCM3 exhibited superior moisture regulation performance and thermal storage capacity, which can effectively mitigate environmental temperature and humidity fluctuations. Therefore, the novel MDE-MPCM3 has considerable potential in energy storage and improving environmental comfort.