细乳液界面聚合模板法制备双壁相变材料纳米胶囊

Preparation of double-shell nanoencapsulated phase change materials by interfacial polymerization in an emulsion system

通过细乳液界面聚合法制备出了以正十八烷为囊芯,聚脲为壁材的纳胶囊,再以此聚脲壁材为模板,使苯乙烯与交联剂二乙烯基苯在内表面共聚形成双层壁材相变材料纳胶囊。采用扫描电子显微镜,差示扫描量热仪,热重分析仪,粒度分析,红外光谱等手段分别考察了纳胶囊的表面形态、相变性能、热稳定性能、粒径分布及胶囊结构等。实验结果表明,超声乳化5min,所得纳胶囊粒径分布均匀,平均粒径在0.41μm,无过冷现象,囊芯含量高达50%,耐热温度达206℃。

The nanoencapsulated phase change materials （NanoPCMs） with polyurea/crosslinked polystyrene as double-shell have been prepared. In the first step, nanoencapsulated n-octadecane was prepared using polyurea as shell by interracial miniemulsion polymerization. In the second step, with formed polyurea layer as a novel template, through copol- ymerization styrene with divinyl benzene in the inner surface of the template to obtain a double-shell nanocapsule. Furthermore, the surface morphology, phase change properties, thermal stability, diameter distribution and the structure of the nannocapsules were investigated by scanning electronic microscopy, differential scanning calorimetry, thermogravimetry, laser particle size analysis and fourier transform infrared spectroscopy. The results showed that, the average diameter of the nanocapsule was about 0. 41 um and the distribution of diameter was narrow under the optimum experimental conditions. Super cooling phenomenon was not observed in the differential scanning calorimetry curve. The contents of n-octadecane in the nanocapsule were as high as 50%,and its heat-resistance temperature was up to 206℃.