Novel Solution Microstructures by "Physcial Synthesis"

9319447卡勒在头两年的研究期间，利用电子显微镜、光学、X射线和中子散射、时间分辨荧光猝灭和NM自扩散测量，在合成和生物表面活性剂体系中发现并表征了一系列新的微结构。扩大表面活性剂溶液微观结构的范围(从简单胶束和片层相的限制)的关键是通过混合表面活性剂来获得所需的一系列性能的新材料的“物理合成”。这一点在我们在第一个研究期间发现和研究的阳离子囊泡系统中得到了最明显的证明。阳离子表面活性剂十六烷基三甲基对甲苯磺酸铵(CTAT)和阴离子表面活性剂十二烷基苯磺酸钠(SDBS)在溶液中缔合形成准双尾表面活性剂，形成双层而不是胶束。与共价键合的两性离子双尾表面活性剂相比，共价结合两性离子双尾表面活性剂的双层膜具有不同的性质；双阳离子混合物形成单层囊泡，而共价两性离子表面活性剂形成多层相。假设在混合物中会产生新的微观结构，因为分子间和聚集间的作用力以在单一组分表面活性剂溶液中不可能发生的方式改变。在这一更新中，通过了解表面活性剂混合物的组成如何改变分子间和聚集间的作用力，实验和理论工作被用来设计混合表面活性剂体系的新的微观结构。***

9319447 Kaler In the first two-year research period, electron microscopy, light, X-ray and neutron scattering, time resolved fluorescence quenching, and NM self-diffusion measurements were used to discover and chartreuse a menagerie of novel microstructures in synthetic and biological surfactant systems. The key to enlarging the realm of surfactant solution microstructure (from the limits of simple micelles and lamellar phases) has been the "physical synthesis" of new materials by mixing surfactants to achieve a desired set of properties. This has been most clearly the demonstrated in the catanionic vesicle systems we discovered and investigated during the first research period. The cationic surfactant cetyl trimethylammonium tosylate (CTAT) and the anionic surfactant sodium dodecylbenzene sulfonate (SDBS) associate in solution to form a quasi-double-tailed surfactant that forms bilayers rather than micelles. The bilayers of the catanionic mixture have different properties than do covalently bound zwitterionic double-tailed surfactants; the catanionic mixture forms unilamellar vesicles while the covalent zwitterionic surfactants form multilamellar phases. It is hypothesized that new microstructures are produces in mixtures because the intermolecular and interaggregate forces are altered in ways impossible in single component surfactant solutions. In this renewal, experimental and theoretical efforts are used to design new microstructures of mixed surfactant systems by understanding how the components of the surfactant mixtures alter the intermolecular and inter-aggregate forces. ***