Acquisition of Analytical Ultracentrifuge for the Study of Interaction of Surfactants and Polymers

购买分析超速离心机用于研究表面活性剂和聚合物的相互作用

• 批准号: 9905217
• 负责人: Ponisseril Somasundaran
• 金额: $ 13.07万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-15 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9905217&HistoricalAwards=false
• 关键词: Acquisition; Analytical; Ultracentrifuge; Study; Interaction

ABSTRACTCTS-9905217Somasundaran, P.Columbia UniversityA large number of aqueous and non-aqueous based systems in the nature and commerce contains one or more polymer and surfactants in the same solution or suspension. In such systems, interactions between polymers and surfactants, as well as changes resultant in properties conferred by any "complex" formed by such interactions, can be of considerable importance in biological systems such as membranes and carriers (lipid transport), and commercial systems of foods, pharmaceutics, cosmetics, detergents and various other chemical systems. Many commercial products containing such mixtures has been widely used in different areas, but formulation of these products has mainly depended on trial and error tests. Clearly a full knowledge of the interaction characteristics of relevant polymers and surfactants will greatly aid the development of efficient products. Toward this purpose we propose to acquire an analytical ultracentrifuge comprising two optical systems for determining concentration distribution. Two important types of experiments can be performed with the analytical ultracentrifuge: in the sedimentation equilibrium experiments, a steady state condition is allowed to develop in which the tendency of a sample to sediment in the centrifugal field is counterbalanced by its tendency to diffuse against the concentration gradient so established. In the sedimentation velocity experiment, the speed with which a molecule moves toward the bottom of the cell is determined. This yields the sedimentation coefficients, and the diffusion coefficient D, which can be related to the molecular weight and the frictional coefficient related to the shape of macromolecules ranging in size from several thousand to tens of millions of dolton. Studies that can be conducted on the dynamics of interactions of polymers and surfactants in solutions using this technique would provide a quantum leap in our knowledge of the behavior of surfactants, polymers and their mixtures. We will be able to use analytical ultracentrifuge also in our study of surfactant, mixtures to understand the relationship between surfactant type, mixing ration and the shape, composition and structure of mixed micelles. Another application will be in our work on coating and coagulation of nanosized particles for preparation of nanocomposites that could lead to significant advance in composite fabrication. Recently, we have expanded our studies of surface adsorption phenomena into the area of polymer (protein)-surfactant mixture systems. The unique capability of the Analytical Ultracentrifuge to provide direst information on the molecular weight distribution of polymer (protein)-surfactant complexes is invaluable in the study of Nan-size polymer-surfactant domains and the solubility of these domains. The acquisition of an Analytical Ultracentrifuge System will thus great enhance the capabilities of Columbia University NSF IUCR Center for Advanced Studies in Novel Surfactants, and will enable us to explore the rapidly expanding frontiers of surfactant and polymer applications.

哥伦比亚大学Somasundaran-9905217自然界和商业中的大量基于水和非水的体系在同一溶液或悬浮液中包含一种或多种聚合物和表面活性剂。在这种体系中，聚合物和表面活性剂之间的相互作用，以及由这种相互作用形成的任何“络合物”所产生的性质变化，在生物系统，如膜和载体(脂类运输)，以及食品、药品、化妆品、洗涤剂和各种其他化学系统的商业系统中，可能具有相当重要的作用。许多含有这类混合物的商业产品在不同领域得到了广泛的应用，但这些产品的配方主要依赖于试错试验。显然，充分了解相关聚合物和表面活性剂的相互作用特性将极大地帮助开发高效产品。为此，我们建议获得一种分析性超速离心机，它包括两个用于确定浓度分布的光学系统。分析型超速离心机可以进行两种重要的实验：在沉积平衡实验中，允许形成一个稳定的条件，在该条件下，样品在离心场中的沉积倾向被其向如此建立的浓度梯度扩散的倾向所抵消。在沉降速度实验中，分子向细胞底部移动的速度是确定的。这就产生了沉降系数和扩散系数D，它们可以与分子质量和与大分子形状有关的摩擦系数有关，大分子的大小从几千到几千万道尔顿不等。利用这一技术对聚合物和表面活性剂在溶液中相互作用的动力学进行研究，将使我们对表面活性剂、聚合物及其混合物的行为的认识有一个巨大的飞跃。我们还将能够在表面活性剂混合物的研究中使用分析超速离心机，以了解表面活性剂类型、混合比例和混合胶束的形状、组成和结构之间的关系。另一个应用将是我们在制备纳米复合材料的纳米颗粒的涂层和凝聚方面的工作，这可能会导致复合材料制造的重大进步。最近，我们将对表面吸附现象的研究扩展到聚合物(蛋白质)-表面活性剂混合体系。分析型超速离心仪能够提供有关聚合物(蛋白质)-表面活性剂复合体分子量分布的最直接信息，这对于研究纳米尺寸的聚合物-表面活性剂结构域以及这些结构域的溶解性是非常宝贵的。因此，收购分析型超速离心机系统将极大地增强哥伦比亚大学NSF IUCR新型表面活性剂高级研究中心的能力，并使我们能够探索表面活性剂和聚合物应用的快速扩展的前沿。