Dainton Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, South Yorkshire, S3 7HF United Kingdom.
Langmuir. 2012 Jan 17;28(2):1196-205. doi: 10.1021/la204539c. Epub 2011 Dec 28.
Block copolymer vesicles are conveniently prepared directly in water at relatively high solids by polymerization-induced self-assembly using an aqueous dispersion polymerization formulation based on 2-hydroxypropyl methacrylate. However, dynamic light scattering studies clearly demonstrate that addition of small molecule surfactants to such linear copolymer vesicles disrupts the vesicular membrane. This causes rapid vesicle dissolution in the case of ionic surfactants, with nonionic surfactants proving somewhat less destructive. To address this problem, glycidyl methacrylate can be copolymerized with 2-hydroxypropyl methacrylate and the resulting epoxy-functional block copolymer vesicles are readily cross-linked in aqueous solution using cheap commercially available polymeric diamines. Such epoxy-amine chemistry confers exceptional surfactant tolerance on the cross-linked vesicles and also leads to a distinctive change in their morphology, as judged by transmission electron microscopy. Moreover, pendent unreacted amine groups confer cationic character on these cross-linked vesicles and offer further opportunities for functionalization.
两亲性嵌段共聚物囊泡可以在水中通过聚合诱导自组装方便地制备，其在较高的固体含量下，使用基于 2-羟丙基甲基丙烯酸酯的水分散聚合配方，即可直接制备。然而，动态光散射研究清楚地表明，向此类线性共聚物囊泡中添加小分子表面活性剂会破坏囊泡膜。在离子型表面活性剂的情况下，这会导致囊泡迅速溶解，而非离子型表面活性剂的破坏程度则略低。为了解决这个问题，可以将甲基丙烯酸缩水甘油酯与 2-羟丙基甲基丙烯酸酯共聚，所得的环氧官能嵌段共聚物囊泡可以在水溶液中使用廉价的商业可得的多聚胺很容易地交联。这种环氧-胺化学赋予交联囊泡对表面活性剂的非凡耐受性，并且根据透射电子显微镜的判断，还导致其形态发生明显变化。此外，未反应的侧基伯胺赋予这些交联囊泡阳离子特性，并为进一步功能化提供了机会。
