Microencapsulated phase change materials composited Al₂O₃–SiO₂ aerogel and the thermal regulation properties

Phase change materials (PCMs) are effective energy storage application, which can be combined with aerogels to improve heat conversion rate in building insulation materials. A low-cost microencapsulated PCMs (MEPCM) composited Al₂O₃–SiO₂ aerogels (MEPCM/ASA) have been successfully prepared by in situ sol–gel method following by ambient pressure drying (APD). The aerogels and the phase change microcapsules were well bonded without destroying the aerogels network structure. The morphology, microstructure, thermal conductivity, energy storage efficiency, and thermal stability of the MEPCM/ASA composite were comprehensively investigated. The experimental results showed that the composite revealed small shrinkage (4.1 wt%), high specific surface area (380.22 m²/g), and low thermal conductivity (0.0507 W/(m K)) at room temperature. The latent heat of the composites containing 50 wt% MEPCM reached 28.91 J/g around 26.7 °C. The MEPCM/ASA possessed good phase change behavior, low undercooling, and excellent thermal cycling stability. It was anticipated to provide a new path to achieve simultaneous enhancement of thermal insulation and thermal storage, and the application in building materials were of great importance for energy saving.