State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
Langmuir. 2010 Jun 1;26(11):8697-703. doi: 10.1021/la904431z.
The self-assembly and pH- and thermo-sensitivities properties of hydroxypropyl cellulose-graft-poly(N,N-dimethyl aminoethyl methacrylate) (HPC-g-PDMAEMA) copolymers in aqueous solutions were investigated by transmittance, dynamic light scattering (DLS), and (1)H NMR spectroscopy. Micelles with different structure can be formed by varying either pH value or temperature. At low pH, e.g., 3.0, the HPC backbone of the copolymer collapse to form the core of micelles stabilized with protonated PDMAEMA side chains on the surface of the micelles upon heating. At the medium pH, e.g., 8.1, both HPC backbone and PDMAEMA side chains collapse upon heating to form unstable aggregates. At high pH, e.g., 12.3, PDMAEMA side chains collapse first to form the core of micelles stabilized with HPC chains upon heating. Further heating the copolymer solution at this pH leads to the aggregation of the micelles due to the collapse of the shell HPC chains. The thermal sensitivity of the HPC-g-PDMAEMA copolymers is reversible.
羟丙基纤维素接枝聚（N，N-二甲基氨基乙基甲基丙烯酸酯）（HPC-g-PDMAEMA）共聚物在水溶液中的自组装以及 pH 值和温度敏感性通过透光率、动态光散射（DLS）和（1）H NMR 光谱进行研究。通过改变 pH 值或温度可以形成具有不同结构的胶束。在低 pH 值（例如 3.0）下，共聚物的 HPC 主链在加热时坍缩形成胶束的核，胶束表面的质子化 PDMAEMA 侧链稳定。在中等 pH 值（例如 8.1）下，HPC 主链和 PDMAEMA 侧链在加热时坍缩形成不稳定的聚集体。在高 pH 值（例如 12.3）下，PDMAEMA 侧链首先坍缩形成胶束的核，加热时 HPC 链稳定。在该 pH 值下进一步加热共聚物溶液会由于壳 HPC 链的坍缩导致胶束聚集。HPC-g-PDMAEMA 共聚物的热敏感性是可逆的。
