光酸响应聚合物胶束的分子捕捉、转移与释放性能

"苍鸟群飞，何使萃之？" 同样，在微观领域如何控制特定分子的收集、相转移迁移与定点释放？本项目设计了这样一类光响应物理胶束：胶束的核由一个多官能团的超支化聚合物构成，壳则由极性与核相反的分子构成，核-壳间通过光敏的环糊精和偶氮苯基团间的包结作用连接。该胶束具有以下特点：因核内带有多个脂肪氮原子而具有酸碱响应性；核带有大量官能团，经化学修饰后能主动地、高选择性地收集指定的客体分子；最重要的是核为单个超支化聚合物分子，使胶束能反复自组装/自拆卸，在某种光的照射下，自组装胶束捕捉客体分子并定向迁移至油相（水相），在另一波长的光照下胶束解体，客体分子重返水相（油相）。由于该过程可以反复进行，胶束可用于催化剂回收、混合物分离和水污染物清除。另外，胶束还具有强大的功能集成能力，当将聚环氧乙烷以酸敏的希夫碱与核共价连接，并在所得的胶束内装载双光子响应的光生酸剂后，胶束就能进行精确定位的药物释放。

"What calls birds together and let them fly in flocks?" Similarly in microscopic field, how to conduct collection, phase transfer delivery and localized release of specified molecules? In this program, such a photo-responsive physical micelle is designed: the core consists of a multifunctional hyperbranched polymer, and the shell is composed of a chain with reverse polarity to the core, where the shell attaches to the core via a photo-responsive azobenzyl/cyclodextrin inclusion complexation. This micelle is of such features: pH responsive due to the aliphatic nitrogen atoms in the core; owing to the multifunctional groups in the core, chemical modification can lead to active and highly selective entrapment of specified molecules; most importantly, because the core is a hyperbranched polymer, repeated self-assembly/disassembly is feasible for the micelle, with the irradiation of certain photo, self-assembled micelle entraps the guest and migrates into organic (aqueous) phase, while under the trigger of another photo, micelle collapses and the released guests move back into aqueous (organic) phase. Owing to the reversibility of this process, the micelle can be used for catalyst recycle, mixture separation and removal of pollutants. Additionally, the micelle is ready for function integration, when poly(ethylene glycol)s are attached to the core via acid-labile Schiff bonds and two-photo responsive photo-acid generators are encapsulated in the resulting micelle, precisely localized drug release is possible for the micelle.