Sepiolite-zeolite powder doped with capric acid phase change microcapsules for temperature-humidity control.

A composite material with temperature-humidity control functions was prepared by using sepiolite-zeolite powder as humidity control matrix and capric acid phase change microcapsules as temperature control material. The micromorphology, thermal conductivity, compressive strength, hygrothermal effect were studied by environmental scanning electron microscope (ESEM), thermal conductivity test, strength test and hygrothermal effect test, respectively. The results showed that the phase change temperature of capric acid phase change microcapsule is between 31 °C ~ 32 °C, the phase change enthalpy is 123.91 J/g, and it has good thermal stability. The humidity control performance is the best and the maximum humidity absorption rate is 6.28% when sepiolite-zeolite powder ratio is 9:1. The humidity control matrix@CAM (Capric acid microcapsules) can control the relative humidity of the environment at 51.74 ~ 58.54% and reduce the temperature fluctuation range by 2 °C ~ 3 °C. Capric acid phase change microcapsules are embedded in the interlaced sepiolite and zeolite powder to form a frame space body which produce capillary condensation adsorption and surface adsorption, absorb and desorb heat through phase changes, thus giving humidity control matrix@CAM a good temperature-humidity control performance.