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 Cross-linking Method

以螺吡喃光致变色染料为芯材、壳聚糖为壁材,采用乳化-化学交联法制备了粒径分布窄、平均粒径较小的光致变色壳聚糖微胶囊。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：当乳化剂为质量分数5%的Tween80水溶液、超声时间120 min、芯壁质量比为1∶3时,制得的微胶囊粒径分布范围窄,平均粒径3.2μm,密封性良好,能耐受300℃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、26.00s,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灵敏性。

A kind of photochromic microcapsule with a narrow particle size distribution and smaller average particle size was prepared by emulsification-chemical cross-linking method with spiropyran photochromic dye as core material and chitosan as shell material. The effects of emulsifier type, 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 tested. The results showed that the best emulsifier was Tween80 aqueous solution（mass fraction 5%）. Ultrasonic time was 120 min and core/shell mass ratio was 1∶3. Under these conditions, the microcapsule exhibited a narrow particle size distribution and an average particle size of 3.2 μm. Moreover, the prepared microcapsule had good leakproofness and was able to withstand the high temperature about 300 ℃. The time of photochromic microcapsule dispersion liquid needed to achieve the steady state during coloration process and the time of photochromic microcapsule dispersion liquid lost the steady state during decoloration process were 4.25 s and 26.00 s, which were 0.25 s and 4.00 s higher than that of the photochromic dye dispersion liquid, respectively. The results indicated that the photochromic microcapsule had good photochromic reversibility.