GOALI: Colliods, Surfactants, and Polyelectrolytes

目标：胶体、表面活性剂和聚电解质

• 批准号: 0625047
• 负责人: Norman Wagner
• 金额: --
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0625047&HistoricalAwards=false
• 关键词: GOALI; Colliods; Surfactants; Polyelectrolytes

ABSTRACTNano-scale self-assembly of polyelectrolyte with surfactant into structured 'complex' fluids is at the heart of many contemporary scientific and commercial endeavors. It is a major emphasis of the specialty chemical industry, and enables advances in personal care products. The same chemistry and physics also dominates the non-specific interactions in biological systems and plays an important role in downstream purification and formulation of proteins and other pharmaceuticals. Despite the obvious importance these mixtures, there are significant gaps in the understanding of how polyelectrolytes and surfactants interact to form specific microstructures and to dictate colloidal-scale properties. The structures are typically on the nanometer-scale and are used to create systems that can be functionalized for specific tasks including drug delivery, materials templating, or catalysis; the colloidal interactions often define properties such as rheology and product stability. This project addresses the science and engineering needed to advance the formulation of polyelectrolytes and surfactants, and combines the resources of an academic laboratory with those of the dominant US industrial laboratory in this field.The basic theme is experimental study of mixtures of polyelectrolyte with either same or oppositely charged surfactants, with two specific aims: 1. Investigate the microstructure and phase behavior of mixtures of mechanically-formed vesicles made from insoluble surfactants (R ~ 15 nm) and same-charged polyelectrolyte (Rg ~ 100 nm), in what is often referred to as the nano-particle limit (i.e., Rg R). Emphasis will be on understanding the role polymer characteristics such as flexibility and inter-polymer interactions (e.g., virial coefficients and specific surfactant-polymer interactions) play in the colloidal-scale structure of these mixtures. There is particular interest in the dilute and semidilute polymer concentration regime, which can be interpreted in the context of the Polymer Reference Interaction Site Model (PRISM), as well as in concentrated regimes that reflectpractical product formulations. 2. Investigate in a methodical and systematic way the interactions of polyelectrolyte and soluble surfactants. With one exception, the project will focus on the study of weak polyelectrolyte (in which the charge groups are weak acids or bases). Features to be explored include binding isotherms, the molecular features of the polyelectrolyte (charge density, backbone rigidity, and molecular weight), configurations of polymer/surfactant aggregates, and the characteristics of resulting gel phases and aggregates. Of particular interest will be documentation of the competition between cationic polymer and cationic surfactant for association with anionic surfactant, and the role of hydrotropes. While these specific aims reflect specific industry needs, this work should also provide a set of rational design rules relevant to all nano-material formulations.Intellectual Merit: The experimental results of the project will provide a motivation for extension and development of PRISM-like theories, while at the same time providing empirical rules for product design. The tandem of cryo-visualization and scattering willprovide new insights into the binding and organization of soluble polyelectrolyte/surfactant complexes heretofore not available for weak polyelectrolytes, and the systematic phase and structure work will enable observation of new patterns. Broader Technical Impact: The commercial value of this work is potentially enormous, with surfactant/polymer industries generating multi-billion dollars in revenue per annum. The scientific aspects of this proposed work will enable discovery of new patterns of colloidal stability and microstructure evolution. This will be significant for both Procter & Gamble as well as the broader colloid community. Broader Social Impact: Undergraduate and graduate students involved in this work will be exposed to a range of characterization tools in preparation for either academic or industrial work. Visualization studies by electron microscopy are especially appealing to K-12 students, who will be exposed to concepts relevant to this work, including surfactant and polymer properties and elements of nanotechnology.

纳米尺度的表面活性剂自组装成结构复杂的流体是许多当代科学和技术的核心。 商业努力。它是特种化学工业的重点，并使个人护理产品的进步。同样的化学和物理也主导着生物系统中的非特异性相互作用，并在下游纯化和蛋白质和其他药物的配制中发挥重要作用。尽管这些混合物具有明显的重要性，但在理解聚电解质和表面活性剂如何相互作用以形成特定的微观结构并决定胶体尺度性质方面存在重大差距。这些结构通常在纳米尺度上，用于创建可以功能化用于特定任务的系统，包括药物递送，材料模板或催化;胶体相互作用通常定义流变学和产品稳定性等特性。该项目致力于推进聚电解质和表面活性剂配方所需的科学和工程，并将学术实验室的资源与该领域占主导地位的美国工业实验室的资源相结合。基本主题是对聚电解质与相同或相反电荷的表面活性剂的混合物进行实验研究，有两个具体目标： 1.研究由不溶性表面活性剂（R ~ 15 nm）和带相同电荷的表面活性剂（Rg ~ 100 nm）制成的机械形成的囊泡的混合物的微观结构和相行为，通常被称为纳米颗粒极限（即，Rg R）。重点将是理解聚合物特性的作用，如柔性和聚合物间的相互作用（例如，维里系数和特定的表面活性剂-聚合物相互作用）在这些混合物的胶体尺度结构中起作用。特别感兴趣的是稀释和半稀释的聚合物浓度制度，这可以解释的聚合物参考相互作用网站模型（PRISM）的上下文中，以及在集中的制度，reflectpractical产品配方。 2.用有条理和系统的方法研究水溶性表面活性剂和水溶性表面活性剂的相互作用。除了一个例外，该项目将侧重于研究弱酸（其中电荷基团是弱酸或弱碱）。要探讨的功能包括结合等温线，的分子特征的电荷密度，骨架刚度，和分子量，聚合物/表面活性剂聚集体的配置，以及所得的凝胶相和聚集体的特性。特别感兴趣的将是文件的阳离子聚合物和阳离子表面活性剂之间的竞争与阴离子表面活性剂的协会，和水溶助长剂的作用。虽然这些具体的目标反映了特定的行业需求，这项工作也应该提供一套合理的设计规则相关的所有纳米材料formulation.Intellectual优点：该项目的实验结果将提供一个动机的扩展和发展的PRISM类理论，而在同一时间提供经验规则的产品设计。低温可视化和散射的串联将为迄今为止弱聚电解质无法获得的可溶性聚乙烯/表面活性剂复合物的结合和组织提供新的见解，并且系统的相和结构工作将能够观察到新的模式。 更广泛的技术影响：这项工作的商业价值可能是巨大的，表面活性剂/聚合物行业每年产生数十亿美元的收入。这项拟议工作的科学方面将能够发现胶体稳定性和微观结构演变的新模式。这对宝洁公司和更广泛的胶体界都具有重要意义。 更广泛的社会影响：参与这项工作的本科生和研究生将接触一系列表征工具，为学术或工业工作做准备。通过电子显微镜的可视化研究是特别吸引K-12学生，谁将接触到相关的概念，这项工作，包括表面活性剂和聚合物的性能和纳米技术的元素。