Preparation and performance research of functional geopolymer filled with microencapsulated phase change materials enhanced by modified graphite

Energy consumption and carbon emission of building account for a large proportion of the world's total. Consequently, choosing environmentally friendly geopolymer and endowing it with thermal storage-release function as the building material applied in energy-efficient buildings can reduce energy consumption and carbon emission in the production of building materials and operation of buildings. In this study, a series of Microencapsulated Phase Change Materials (MPCM) enhanced by modified microcrystalline graphite were synthesized successfully, which have favorable thermal storage-release performance. And the structural characteristics and performances were studied. Among them, MPCM with better performance and low cost was filled into alkali-activated metakaolin-based geopolymer to functionalize it. In the meantime, thermal conductivity, thermal storage performance and compressive strength of the functional geopolymer were characterized. According to the results, the functional geopolymer has a maximum heat preservation effect of 3.5 °C compared to the blank geopolymer without significantly decrease in the thermal conductivity. This study conducts copolymerization method to prepare hydrophilic shell MPCM, which contraposes the mechanical property limitation of the functional geopolymer. And the mechanical property of geopolymer functionalized by copolymer shell MPCM meets the requirements of EN 998–2:2016 class M20.