Preparation and performance evaluation of paraffin@SiO2 microencapsulated phase change material and its thermal insulation effect in architectural coatings

Room temperature phase change materials have significant potential to enhance energy conservation; however, their application is limited by issues such as leakage and compatibility. In this study, paraffin was microencapsulated using advanced microencapsulation technology to address these challenges. Sodium silicate was employed as a silicon source, while methyltriethoxysilane (MTES) served as a modifier. Paraffin@SiO₂ microencapsulated phase change material (MEPCM) was prepared using the chemical precipitation method. The results demonstrated that, under reaction conditions of 45 °C, a pH of 3.5, a core-to-shell ratio of 1:1, and a composite emulsifier consisting of cetyltrimethylammonium bromide (CTAB) and OP-10, the core material content reached 75.52 %, which was 23.09 % higher than that of the unmodified sample. Additionally, the melt permeability rate decreased to 9.14 %. When 10 % MEPCM was incorporated into emulsion paint, the film maintained good performance and significantly extended the heat preservation time by 19.44 %. This study provides a practical strategy for developing cost-effective, high-stability building phase change coatings.