Institute of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University, Jena, Humboldtstrasse 10, 07743, Jena, Germany.
Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany.
Macromol Rapid Commun. 2020 Mar;41(6):e1900607. doi: 10.1002/marc.201900607. Epub 2020 Feb 9.
The synthesis of a photoresponsive amphiphilic diblock quarterpolymer containing 5-vinyl-1-naphthol (VN) as a photostable photoacidic comonomer is presented. The preparation is realized via a sequential reversible addition fragmentation chain transfer (RAFT) polymerization starting from a nona(ethylene glycol) methyl ether methacrylate (MEO MA/"O") hydrophilic block, which is then used as a macro-RAFT agent in the terpolymerization of styrene (S), 2-vinylpyridine (2VP), and TBS-protected VN (tVN). The terpolymerization proceeds in a controlled fashion and two diblock quarterpolymers, P(O )-b-P(S -co-2VP -co-VN ), with varying functional comonomer compositions are prepared. These diblock quarterpolymers form spherical core-corona micelles in aqueous media according to dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM). Upon irradiation, the photoacids within the micellar core experience a drastic increase in acidity causing a proton transfer from the photoacid to neighboring 2VP units. As a result, the hydrophilic/hydrophobic balance of the entire assembly is shifted, and the encapsulated cargo is released.
本文介绍了一种光响应性两亲性嵌段四聚体的合成，该嵌段四聚体包含 5-乙烯基-1-萘酚（VN）作为光稳定的光酸性共聚单体。该制备方法是通过顺序可逆加成-断裂链转移（RAFT）聚合从非甲氧基聚乙二醇甲基醚甲基丙烯酸酯（MEO MA/"O"）亲水性嵌段开始，然后将其用作苯乙烯（S）、2-乙烯基吡啶（2VP）和 TBS 保护的 VN（tVN）的三聚体聚合的大分子 RAFT 试剂。三聚体聚合以可控的方式进行，制备了两种具有不同功能共聚单体组成的嵌段四聚体，P（O）-b-P（S-co-2VP-co-VN）。这些嵌段四聚体在水介质中形成球形核-冠形胶束，根据动态光散射（DLS）和低温透射电子显微镜（cryo-TEM）。光照后，胶束核内的光酸经历酸度的急剧增加，导致光酸向邻近的 2VP 单元转移质子。结果，整个组装体的亲水/疏水平衡发生了转移，被包裹的货物被释放出来。
