以高岭石稳定的Pickering乳液为模板制备高岭石聚脲微胶囊及相变性能研究

相变微胶囊以其优异的储热性能被广泛用于建筑节能等领域,但是,由于传统相变微胶囊常以表面活性剂所稳定的乳液为模板,由单一高分子聚合物形成囊壁,导致其热稳定性和储热性能较低。本文通过在高岭石稳定的水/石蜡乳液界面处引发异佛尔酮二异氰酸酯和水发生聚合反应,成功获得了囊壁为高岭石聚脲包封客体为石蜡的相变微胶囊。结果表明:相变微胶囊形貌规整呈球形,微胶囊平均粒径为42μm并可通过调控乳液液滴大小实现尺寸调控;该微胶囊的石蜡包封率达85.3%,相变点为49.6℃,热分解温度为218℃,相变潜热高达175.7 J/g。以高岭石稳定的Pickering乳液为模板所制备的相变微胶囊具有良好的热稳定性和相变潜热,有望作为相变储热材料应用于节能领域。

The preparation and phase transition properties of microcapsules using kaolinite-stabilized Pickering emulsions as template

Phase change microcapsules are widely used in building energy-saving and other fields due to their excellent heat storage performance.However,conventional phase change microcapsules are generally composed by single polymer materials,and prepared with surfactant-stabilized emulsion as a template,thus suffered poor thermal stability and low heat storage performance.In this work,a paraffin-loaded kaolinite polyurea microcapsule was prepared based on the polymerization reaction of isophorone diisocyanate with water at the interfaces of a kaolinite-stabilized water/paraffin emulsion,forming a kaolinite polyurea composite material capsule wall.The results showed that the shape of the phase change microcapsules was regularly spherical.The average size of the microcapsules was 42μm and could be tuned by controlling the emulsion droplet size.The encapsulation rate of the paraffin in microcapsules was up to 85.3%.The phase change point and thermal decomposition temperature of the microcapsules were 49.6℃and 218℃,respectively.The latent heat of the microcapsules was 175.7 J/g.The phase change microcapsules prepared using the kaolinite-stabilized Pickering emulsions as a template had good thermal stability and phase change latent heat,which could be used as phase change energy storage material.