Pathway-dependent re-assembly of dual-responsive ABC terpolymer in water
Pathway-dependent re-assembly of dual-responsive ABC terpolymer in water
复制标题
双响应 ABC 三元共聚物在水中的路径依赖性重组装
DOI：
10.1039/c2sm07063d
复制
发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Li, Zhibo
中科院分区：
文献类型：
--
作者：
Luo, Chunhui;Liu, Yu;Li, Zhibo
以聚甲基丙烯酸正丁酯（PDMAEMA）为端基，通过RAFT聚合制备了一种聚乙二醇-b-聚甲基丙烯酸正丁酯-b-聚甲基丙烯酸二甲氨基乙酯（PEG-b-PnBMA-b-PDMAEMA）三嵌段共聚物。PEG-b-PnBM-Ab-PDMAEMA在酸性溶液中自组装成球形胶束，在碱性溶液中自组装成圆柱形胶束。这种pH诱导的重新组装是可逆的。此外，我们还发现，在稀水溶液中，当溶液pH值和温度发生程序性变化时，这种囊泡经历了从圆柱体到环形体或囊泡的路径依赖性重新组装。使用动态光散射（DLS）和低温透射电子显微镜（cryoTEM），我们发现，这种刺激诱导的重新组装从圆柱体到环形或囊泡显然是不可逆的，和原始形态的恢复只发生在使用不同的外部刺激。我们的研究展示了智能超分子组装的原型，我们可以使用不同的刺激重新组装成不同的胶束形态。
A poly(ethylene glycol)-b-poly(n-butyl methacrylate)-b-poly(N,N'-dimethylamino ethyl methacrylate) (PEG-b-PnBMA-b-PDMAEMA) triblcok terpolymer with a dual pH-and thermo-responsive PDMAEMA as end segment was prepared via sequential RAFT polymerization. The PEG-b-PnBM-Ab-PDMAEMA self-assembled into spherical micelles in acidic solution but transformed into cylindrical micelles in alkaline solution. This pH induced re-assembly was reversible. Moreover, we found that this terpolymer underwent a pathway dependent re-assembly from cylinder to toroid or to vesicle upon programmed variation of solution pH and temperature in dilute aqueous solution. Using dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryoTEM), we found that this stimuli-induced re-assembly from cylinder to toroid or to vesicle was apparently irreversible, and restoration of pristine morphology only happened using different external stimulus. Our studies demonstrated a prototype of smart supramolecular assembly that we can re-assembly into different micelle morphologies using different stimuli.