Growth and Flexibility of Equilibrium Polyelectrolytes

在这个由实验物理化学计划支持的项目中， Magid将利用光散射和 小角中子散射（SANS）研究聚电解质和 在水溶液中自组装的巨胶束的形成 表面活性剂的溶液。 在选定的情况下，胶束溶液 将在类似于某些 应用这些解决方案。 都是自组织的 和共价聚电解质的研究，提供了一个有价值的 桥梁之间什么往往被认为是两个不同的研究领域。 本文提出的SANS实验将提供链上的数据 构象作为固有刚度的函数， 店 特别令人感兴趣的是胶束长度的变化， 随着表面活性剂变化而发生的空间组织（构象 浓度. 这项工作将产生第一个量化的数字 关于胶束生长参数的浓度依赖性 稀溶液 胶束和聚电解质广泛存在于生物系统中， 在那里它们有各种各样的结构和功能作用。 他们是 在消费者和工业应用中也是普遍存在的， 个人护理产品，药物输送系统，粘度调节剂， 食品和聚合物加工、减阻和剪切稀化 热交换器流体、涂料和材料表面改性。 最近的一些理论进展指出，需要新的 像Magid这样的实验数据将在她的线状研究中收集， 胶束和聚电解质对它们的影响。

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Magid will use light scattering and small-angle neutron scattering (SANS) to investigate polyelectrolytes and the formation of giant micelles that are self-assembled in aqueous solutions from surfactants. In selected cases the micellar solutions will be studied in flow fields similar to those found in some of the applications for which these solutions are used. Both self-organizing and covalent polyelectrolytes are to be studied, providing a valuable bridge between what are often considered two different fields of study. The SANS experiments proposed here will provide data on chain conformations as a function of intrinsic stiffness of the polyelectrolyte chains. Of special interest are the changes in micellar length and in spatial organization (conformation) that occur with changes in surfactant concentration. This work will produce the first quantitative numbers concerning the concentration dependence of micellar growth parameters in dilute solutions. Micelles and polyelectrolytes are broadly found in biological systems, where they have a variety of structural and functional roles. They are also ubiquitous in consumer and industrial applications such as personal-care products, drug-delivery systems, viscosity modifiers in foods and in processing of polymers, drag reduction and shear-thinning in heat-exchanger fluids, paints, and surface modification of materials. Several recent theoretical advances have pointed to the need for new experimental data such as Magid will gather in her studies of thread-like micelles and the influence of polyelectrolytes on them.