Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
J Am Chem Soc. 2012 Jun 27;134(25):10365-8. doi: 10.1021/ja303841f. Epub 2012 Jun 13.
The gelation behavior of a poly(ethylene-alt-propylene)-b-poly(ethylene oxide)-b-poly(N-isopropylacrylamide) (PON) triblock terpolymer and a poly(N-isopropylacrylamide)-b-poly(ethylene oxide)-b-poly(N-isopropylacrylamide) (NON) triblock copolymer was studied by rheology over the concentration range 1-5 wt %. In comparison to the NON copolymer, gelation of the PON terpolymer was achieved at a much lower concentration, with a much sharper sol-gel transition. This is due to a stepwise gelation of PON terpolymers involving micellization at room temperature and gelation at elevated temperatures. The separation of micellization and gelation leads to the formation of a two-compartment network as observed by cryoTEM. The results highlight the intricate and tunable nanostructures and new properties accessible from ABC terpolymer hydrogels.
聚（乙烯-alt-丙烯）-b-聚（氧化乙烯）-b-聚（N-异丙基丙烯酰胺）（PON）三嵌段共聚物和聚（N-异丙基丙烯酰胺）-b-聚（氧化乙烯）-b-聚（N-异丙基丙烯酰胺）（NON）三嵌段共聚物的凝胶行为通过流变学在浓度范围 1-5wt% 下进行了研究。与 NON 共聚物相比，PON 三嵌段共聚物的凝胶化在低得多的浓度下实现，具有更陡峭的溶胶-凝胶转变。这是由于 PON 三嵌段共聚物的逐步凝胶化，包括在室温下胶束化和在升高温度下凝胶化。胶束化和凝胶化的分离导致形成了一个两隔室网络，如通过 cryoTEM 观察到的。这些结果突出了 ABC 三嵌段共聚物水凝胶可获得的复杂且可调的纳米结构和新特性。
