二氧化钛包覆石蜡相变微胶囊的制备及表征

Preparation and characterization of titanium oxide-coated microencapsulated paraffin phase change materials

以二氧化钛为壳材、石蜡为芯材、十二烷基硫酸钠为乳化剂,采用溶胶-凝胶法制备相变储能微胶囊。通过单因素实验考察乳化剂质量、乳化转速、p H、芯壳比、钛酸丁酯/无水乙醇比例对微胶囊包覆率的影响。通过实验得出最优工艺条件:乳化剂质量为3. 0 g、乳化转速为1 000 r/min、pH=2. 0、芯壳比为1. 5∶1。微胶囊呈圆球形,粒径在80～90μm之间,微胶囊包覆率达到了69. 36%。利用FT-IR、XRD、DSC、STA和SEM对石蜡、TiO_2壳及微胶囊的化学结构、晶相、热性能、热稳定性能和微观结构进行分析,结果表明,其具有良好的热性能和热稳定性能。

The sol-gel method is used to prepare microcapsulated paraffin phase change materials with titanium dioxide as shell material,paraffin as core material and sodium dodecylsulfate as emulsifier.Single factor experiments are used to investigate the effects of emulsifier dosage,emulsification speed,p H,core-shell ratio and ratio of butyl titanate/anhydrous ethanol on microencapsulation coverage and coating efficiency.The experimental results show that the preferred process conditions are as follows: emulsifier dosage 3. 0 g,emulsification speed 1 000 rpm,p H = 2. 0,core/shell ratio 1. 5∶1. The prepared microcapsules present spherical shape with a particle diameter between 80 μm and 90 μm. The microcapsule coating rate reaches 69. 36%.FT-IR,XRD,DSC,STA,and SEM are used to study paraffin,TiO2 shells,and the chemical structure,crystalline phase,thermal properties,thermal stability and microstructure of the microcapsules.It shows that the microcapsule has good thermal performance and thermal stability.