Singh Jasmeet, Miller Justin, Ranganathan Radha
Department of Physics and Center for Supramolecular Studies, California State University, Northridge, California 91330-8268, USA.
J Phys Chem B. 2007 Aug 9;111(31):9317-24. doi: 10.1021/jp0720340. Epub 2007 Jul 13.
Mixed micelles of solubilized dimyristoyl phosphatidylcholine (DMPC) and the zwitterionic detergent dodecyldimethylammoniopropane sulfonate are characterized employing time-resolved fluorescence quenching (TRFQ), electron spin resonance (ESR), and surface tensiometry toward the goal of investigating interfacial reactions using these micelles as host reaction media. The properties measured are the micelle aggregation numbers, interfacial hydration index, microviscosity, and the critical micelle concentrations for various molar fractions, XDMPC, of DMPC, 0<or=XDMPC<0.35. A complementary interpretation of the experimental results from TRFQ and ESR within the framework of a polar shell model for the mixed micelle yields some microstructural features, including the micelle core radius, polar shell thickness, and the fraction of the total hydrocarbon that overlaps with the micelle-water interface. The results of the characterization are applied in investigating an interfacial reaction; namely, micellar fluorescence quenching. A bulk hydrodynamic model when modified appropriately so as to be applicable to reaction within the interface is shown to describe micellar fluorescence quenching kinetics and also provides some insight into the location of guest molecules in micelles.
采用时间分辨荧光猝灭（TRFQ）、电子自旋共振（ESR）和表面张力测定法对溶解的二肉豆蔻酰磷脂酰胆碱（DMPC）与两性离子去污剂十二烷基二甲基氨丙烷磺酸盐的混合胶束进行了表征，目的是将这些胶束用作主体反应介质来研究界面反应。所测量的性质包括胶束聚集数、界面水合指数、微粘度以及不同摩尔分数XDMPC（0≤XDMPC≤0.35）的DMPC的临界胶束浓度。在混合胶束的极性壳模型框架内，对TRFQ和ESR的实验结果进行互补解释，得出了一些微观结构特征，包括胶束核心半径、极性壳厚度以及与胶束-水界面重叠的总烃部分的比例。表征结果应用于研究一种界面反应，即胶束荧光猝灭。当对一个整体流体动力学模型进行适当修改以适用于界面内的反应时，该模型能够描述胶束荧光猝灭动力学，并且还能对客体分子在胶束中的位置提供一些见解。
