纳米胶囊相变材料的制备

Preparation of nano-encapsulated phase change materials

采用超声波工艺及细乳液原位聚合方法,研制了以聚苯乙烯为囊壁、正十八烷为囊芯的纳米胶囊相变材料;系统探讨了聚合反应各因素对乳胶粒子的形态、胶囊材料热性能的影响。适宜的反应条件为引发剂AIBN0.5%(油相质量分数,下同);链转移剂DDT0.4%;正十八烷与苯乙烯比为1∶1以及复合乳化剂(SDS和OP-10)总量2%,配比为1∶1。实验结果表明胶囊Z均直径124nm,相变焓可达124.4kJ.kg-1。

The nano-encapsulated phase change materials （NEPCMs） with polystyrene as shell and noctadecane as core were synthesized by ultrasonic technique and miniemulsion in-situ polymerization. The influence of various polymerization factors on the morphology and thermal properties of nanocapsules was investigated systematically. The optimal reaction condition was 0.5 % AIBN initiator （mass percent of oil phase, the same in the following）, 0.4% DDT chain transfer agent, 1 ： 1 n-octadecane/styrene, and 2% total amount of composite surfactants consisting of 1 ： 1 SDS and OP-10. The results showed that the Z average diameter of capsules was 124 nm and its phase change latent heat was 124.4 kJ · kg^-1.