乳化-化学交联法光致变色微胶囊的制备及其性能

Preparation and Properties of Photochromic Microcapsule via Emulsification-Chemical Crosslinking Method

摘要:

以螺吡喃光致变色染料为芯材、壳聚糖为壁材，采用乳化-化学交联法制备粒径分布窄、平均粒径较小的光致变色微胶囊。考察了乳化剂种类、超声时间、芯壁质量比对微胶囊粒径的影响，测试了光致变色壳聚糖微胶囊的热稳定性及光致变色响应性能。结果表明：当乳化剂为Tween且在水溶液中的质量分数为5%、超声时间为2 h、芯壁质量比为1:3时，微胶囊粒径分布范围窄，平均粒径3.2 μm，密封性良好，能耐受300 °C左右的高温；光致变色微胶囊分散液达到变色稳态、褪色稳态的时间分别为4.25、26.00 s，较未胶囊化的光致变色染料分散液分别提高了0.25、4.00 s，具有良好的光致变色可逆性。

Abstract:

The photochromic microcapsule with narrow particle size distribution and smaller average particle size was prepared by emulsification-chemical crosslinking method utilizing spiropyran photochromic dye as core material and chitosan as shell material.The effects of emulsifier types, ultrasonic time and core-shell mass ratio on the particle size of microcapsule were investigated. The thermal stability and photochromic properties of photochromic chitosan microcapsule were studied. The results showed that the particle size distribution was narrow and the average particle size was 3.2 μm when the emulsifier was Tween80 and the mass fraction was 5% in the aqueous solution, the ultrasonic time was 2 h and the core-shell mass ratio was 1:3. The microcapsules prepared under these conditions were able to withstand the high temperature about 300 °C.The times of photochromic microcapsule dispersion to achieve color and fade steady state were 4.25 s and 26.00 s, respectively. The time of photochromic microcapsule dispersion to achieve color and fade steady state was only 0.25 s and 4.00 s higher than that of the photochromic dye dispersions. Moreover, the photochromic microcapsule had good photochromic reversibility.