Structure, Energetics and Phase Behavior in Polyelectrolyte-Colloid Systems

聚电解质-胶体系统的结构、能量和相行为

• 批准号: 0076068
• 负责人: Paul Dubin
• 金额: $ 28.3万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0076068&HistoricalAwards=false
• 关键词: Structure; Energetics; Phase; Behavior; Polyelectrolyte

The interactions between polyelectrolytes and small oppositely charged colloids are manifested in some important biological and technological phenomena. In order to rationalize these observations and current theory, experiments on well-defined model systems are essential. Such experiments will be carried out on polyelectrolytes in combination with three classes of well-defined synthetic colloid particles - mixed micelles, dendrimers, and carboxylated Ficoll fractions - and also with proteins. Polymer MW, linear charge density and chain stiffness will be varied systemically, along with colloid size and charge. A wide range of techniques, including turbidimetry and total intensity, electrophoretic light scattering, QELS, fluorescence recovery after photobleaching, SANS, time-resolved fluorescence spectroscopy and rheology will be used to answer questions about the energetics of interaction, the structure of soluble complexes, and phase behavior.%%%In addition to addressing fundamental questions and linking theory with experiment, the work will be of relevance to problems in (1) chemical technology, (2) cell biology, and (3) environmental issues, as follows. (1) Polyelectrolyte-colloid interactions are central to stabilization and flocculation in: water treatment, paper-making, and preceramics. (2) Non-specific polyion-protein association may be an important phenomenon controlling the role of proteoglycans in the extracellular matrix. (3) Complexes between polyelectolytes and micelles adsorbed on sand/soil may serve as barriers in the aquiferous migration of apolar pollutants. Students involved in this work will be exposed to a highly multidisciplinary approach that spans theory and applications.

聚电解质与带相反电荷的小胶体之间的相互作用表现在一些重要的生物和技术现象中。 为了使这些观察和当前的理论合理化，在定义明确的模型系统上进行实验是必不可少的。 这些实验将在聚电解质与三类定义明确的合成胶体颗粒（混合胶束、树枝状聚合物和羧基化Ficoll组分）以及蛋白质的组合上进行。 聚合物分子量、线性电荷密度和链刚度将随胶体尺寸和电荷沿着系统地变化。 广泛的技术，包括比浊法和总强度，电泳光散射，QELS，光漂白后的荧光恢复，SANS，时间分辨荧光光谱和流变学将用于回答有关相互作用的能量学，可溶性复合物的结构和相行为的问题。除了解决基本问题并将理论与实验联系起来外，这项工作还将与以下问题有关：（1）化学技术，（2）细胞生物学和（3）环境问题。 (1)聚电解质-胶体相互作用是水处理、造纸和预处理中稳定和絮凝的核心。(2)非特异性多聚离子-蛋白质结合可能是控制蛋白聚糖在细胞外基质中作用的重要现象。 (3)吸附在砂/土壤上的聚电解质和胶束之间的复合物可以作为非极性污染物的含水迁移的障碍。 参与这项工作的学生将接触到跨越理论和应用的高度多学科方法。