Microcapsules with Macroholes Prepared by the Competitive Adsorption of Surfactants on Emulsion Droplet Surfaces
Microcapsules with Macroholes Prepared by the Competitive Adsorption of Surfactants on Emulsion Droplet Surfaces
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DOI：
10.1021/la800758d
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发表时间：
2008-12-02
期刊：
影响因子：
3.9
通讯作者：
Yoshizawa, Hidekazu
中科院分区：
文献类型：
--
作者：
Kamio, Eiji;Yonemura, Satoshi;Yoshizawa, Hidekazu
我们展示了一种简单、独特的方法来制备壳上有孔的微胶囊。采用相分离法制备交联聚三聚氰胺微胶囊。每个微胶囊的多孔壳是在水包油（O/W）乳液液滴的表面合成的，其中水溶性聚合物表面活性剂和油溶性表面活性剂竞争性吸附。水溶性聚合物表面活性剂提供了壳形成的反应位点。油溶性表面活性剂分子在壳形成时似乎会自组装，因此在它们组装的地方会出现孔。根据考虑竞争吸附的理论计算，形成多孔壳所需的水溶性聚合物表面活性剂对乳液液滴的表面覆盖的临界程度确定为0.90。理论上的考虑表明，微胶囊壳中孔的尺寸和数量是由乳液液滴表面吸附的表面活性剂的组成控制的。这一理论考虑得到了实验的证实。所制备的壳内具有可控大孔的微胶囊具有用于控释应用的潜力，并且可用于制造封装亲水性化合物的微胶囊。
We demonstrate a simple, unique method for preparing microcapsules with holes in their shells. Cross-linked polymelamine microcapsules are prepared by the phase-separation method. The holey shell of each microcapsule is synthesized on the surface of an oil-in-water (O/W) emulsion droplet where a water-soluble polymeric surfactant and an oil-soluble surfactant are competitively adsorbed. The water-soluble polymeric surfactant provides a reaction site for shell formation. The oil-soluble surfactant molecules seem to self-assemble while the shells are being formed, so holes appear where they assemble. The critical degree of surface coverage of an emulsion droplet by the water-soluble polymeric surfactant needed to form the holey shells is determined to be 0.90 from theoretical calculations in which competitive adsorption is considered. Theoretical consideration suggests that the size and quantity of the holes in the microcapsule shells are controlled by the composition of the surfactants adsorbed on the surface of an emulsion droplet. This theoretical consideration is confirmed by experiments. The prepared microcapsule with controllable macroholes in its shell has the potential to be used for controlled release applications and can be used to fabricate a microcapsule that encapsulates hydrophilic compounds.