电泳显示双层微胶囊的制备

以尿素-甲醛原位聚合法与明胶-阿拉伯胶复凝聚法相结合制备了电泳显示双层微胶囊．考察了系统调节剂、搅拌速度、pH值和加醛方式对单层微胶囊粒径分布及表面形貌的影响，以及双层微胶囊与单层脲醛树脂微胶囊在干燥过程中的破损率．实验结果表明，以明胶为系统调节剂，pH值为3．0—3．5，采用滴加方式加入甲醛制备的单层脲醛树脂微胶囊，囊壁透明、光滑、球形度好；单层脲醛树脂微胶囊包覆明胶后制备的双层微胶囊壁材强度和韧性有显著提高．

Preparation of Double Layered Microcapsule for Electrophoretic Display

Double layered microcapsules for electrophoretic display were prepared by in situ polymerization of urea-formaldehyde combined with complex coacervation of gelatin-gum Arabic. Then the paper investigated the influences of different system modifiers, pH value and method of adding formaldehyde to the size distribution and morphologies of microcapsules. And broken rates of monolayer microcapsules as well as double layered microcapsules during drying process were measured and compared. At last, it is found that monolayer microcapsules with good transparence, smooth surface and sphericity could be obtained at the condition of gelatin as system modifier, the pH value between 3.0 and 3.5, and formaldehyde added dropwise. It is also found that the strength and flexibility of monolayer microcapsules are significantly improved after encapsulated by another layer of gelatin.