Exploring novel phase change temperature and humidity control materials lauric acid/expanded vermiculite/MIL-100(Fe)-based for synchronous controlling indoor temperature and humidity

Building materials with temperature and humidity control functions can enhance residential comfort, save energy, and reduce emissions when used for passive building energy efficiency. In the current study, a new category of phase change humidity control material (PCHCM) was developed, which could passively regulate indoor temperature and humidity to achieve a comfortable environment for the human body. The PCHCM was fabricated by physically mixing the highly hygroscopic MIL-100(Fe) with composite phase change material (CPCM), in which the CPCM used lauric acid (LA) as the PCM and expanded vermiculite (EVM) as the carrier. Results demonstrated that incorporating 45% EVM could efficiently address LA leakage. The PCHCMs with 40-50% CPCM mass fraction exhibited excellent thermal and humidity buffering capabilities, with an appropriate melting temperature (42.0-42.1 °C), strong water absorption capacity (0.216-0.258 g/g) under 60% relative humidity (RH), and good moisture buffering capacity (0.0041-0.0047 g/g·%RH). After undergoing thermal and wet cycles, the PCHCM still maintained good thermal reliability and wet stability. The test results indicate that the LA/EVM/MIL-100(Fe) PCHCM holds significant potential in the fields of temperature and humidity regulation as well as in energy-saving buildings.