Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.
Polymer Research Institute, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, P. R. China.
Macromol Rapid Commun. 2018 Aug;39(15):e1800291. doi: 10.1002/marc.201800291. Epub 2018 Jun 20.
ABC triblock copolymer assemblies with reversible "breathing" behaviors based on poly[oligo(ethylene glycol) methyl ether methacrylate]-b-poly(benzyl methacrylate)-b-poly[2-(diethylamino)ethyl methacrylate] (POEGMA-b-PBnMA-b-PDEA) are fabricated via one-pot sequential reverisble addition-fragmentation chain transfer dispersion polymerization. Using a POEGMA as the macromolecular chain transfer agent, chain extension with BnMA and DEA is conducted in ethanol, where PBnMA acts as the core-forming block, and the PDEA block endows the solvophilicity and CO -responsiveness. With the increment of the DP of PBnMA, the morphology of the assemblies evolves from spheres to worms, and to vesicles, while it degenerates from conglutinated vesicles to spheres as the DP of PDEA increases. After replacing ethanol with water, the morphologies of these assemblies remain unchanged, while their size decreases due to the collapse of the hydrophobic PDEA chains. Interestingly, due to the protonation and deprotonation of PDEA blocks, both the spheres and vesicles manifest a reversible expansion/shrinkage upon alternative CO /Ar stimulation, exhibiting distinctive breathing feature.
基于聚[寡聚（乙二醇）甲基醚甲基丙烯酸酯]-b-聚（苄基甲基丙烯酸酯）-b-聚[2-（二乙基氨基）乙基甲基丙烯酸酯]（POEGMA-b-PBnMA-b-PDEA）的 ABC 三嵌段共聚物组装体通过一锅顺序可逆加成-断裂链转移分散聚合来制备。使用 POEGMA 作为大分子链转移剂，在乙醇中进行 BnMA 和 DEA 的链延伸，其中 PBnMA 作为核形成嵌段，而 PDEA 嵌段赋予亲水性和 CO 响应性。随着 PBnMA 的 DP 的增加，组装体的形态从球体演变到蠕虫，再到囊泡，而当 PDEA 的 DP 增加时，形态从粘连的囊泡退化到球体。在用水代替乙醇后，这些组装体的形态保持不变，而由于疏水性 PDEA 链的塌陷，其尺寸减小。有趣的是，由于 PDEA 嵌段的质子化和去质子化，球体和囊泡在交替 CO/Ar 刺激下均表现出可逆的膨胀/收缩，表现出独特的呼吸特征。
