Synthesis and hygrothermal properties of capric-myristic acid/diatomite-based composite phase change materials for...

In this paper, diatomite (DE) served as the supporting material, and capric acid-myristic acid (CA-MA) was utilized as the phase change material (PCM) to synthesize CA-MA/DE composite PCM via the vacuum impregnation method. Leak experimental results indicated that the optimal weight ratio of CA-MA was identified as 40%. The chemical compatibility, thermal properties, and stability of CA-MA/DE were evaluated. The phase temperature and latent heat of CA-MA/DE were obtained as 22.21 °C and 74.07 J g^-1, respectively. To study the feasibility of CA-MA/DE in energy-efficient buildings, CA-MA/DE was used to replace sand of equivalent quality to prepare the CA-MA/DE-based gypsum mortar (CA-MA/DE&GM). The results showed that the replacement rate of CA-MA/DE was determined as 30%, and the thermal properties and humidity regulation performance of CA-MA/DE&GM were significantly enhanced due to the addition of the CA-MA/DE. Notably, the digital image correlation (DIC) technique was employed to investigate the crack evolution mechanism of CA-MA/DE&GM30 (CA-MA/DE content was 30%) over 100 thermal cycles. The novel CA-MA/DE&GM30 can adjust the environmental temperature and humidity simultaneously, which has considerable potential for energy conservation in buildings.