中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 17 Special 1 November 2007 |
(1. Graduated School at Shenzhen, Tsinghua University, Shenzhen 518055, China;
2. Department of Materials Science and Engineering, Tsinghua University, Beijing 100086, China)
Abstract:For thermal energy storage application in energy-saving building materials, silica microcapsules containing phase change material were prepared using sol-gel method in O/W emulsion system. In the system droplets in microns are formed by emulsifying an organic phase consisting of butyl-stearate as core material. The silica shell was formed via hydrolysis and condensation from tetraethyl silicate with acetate as catalyst. The SEM photographs show the particles possess spherical morphology and core-shell structure. The as-prepared silica microcapsules mainly consist of microsphere in the diameter of 3−7 μm and the median diameter of these microcapsules equals to 5.2 μm. The differential scanning calorimetry (DSC) curves indicate that the latent heat and the melting point of microcapsules are 86 J/g and 22.6 ℃, respectively. The results of DSC and TG further testify the microcapsules with core-shell structure.
Key words: silica microcapsules; sol-gel; butyl-stearate; phase change materials