Schaeffel David, Kreyes Andreas, Zhao Yi, Landfester Katharina, Butt Hans-Jürgen, Crespy Daniel, Koynov Kaloian
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
ACS Macro Lett. 2014 May 20;3(5):428-432. doi: 10.1021/mz500169n. Epub 2014 Apr 17.
We investigated the equilibrium chain-exchange kinetics of amphiphilic diblock copolymer micelles, using a new method based on fluorescence correlation spectroscopy. The micelles were formed from polystyrene--poly[oligo(ethylene glycol) methyl ether methacrylate] (PS-POEGMA) in different solvents and studied at various temperatures. This linear-brush copolymer was chosen as a model system, forming micelles with short and bulky corona. Depending on the applied solvent, fast exchange could be observed even at temperatures well below the nominal glass transition of the core-forming PS block. The effect is caused by swelling of the core and allows extensive tuning of the chain-exchange rate by adding to the system minor amounts of good or bad solvent for the core block.
我们使用一种基于荧光相关光谱的新方法，研究了两亲性二嵌段共聚物胶束的平衡链交换动力学。这些胶束由聚苯乙烯-聚[聚（乙二醇）甲醚甲基丙烯酸酯]（PS-POEGMA）在不同溶剂中形成，并在不同温度下进行研究。选择这种线性刷状共聚物作为模型体系，形成具有短而庞大冠层的胶束。根据所使用的溶剂，即使在远低于形成核的PS嵌段的标称玻璃化转变温度的情况下，也能观察到快速交换。这种效应是由核的溶胀引起的，并且通过向体系中添加少量对核嵌段而言的良溶剂或不良溶剂，可以对链交换速率进行广泛调节。
