RUI: Innovative Determination of Phase Diagrams of Green Surfactants in Water and Ionic Liquids

这个由实验物理化学项目支持的项目采用了一种新的方法来更快、更准确地确定一类重要的“绿色”表面活性剂在各种溶剂中的行为。被称为烷基糖苷的表面活性剂被认为是“绿色”的，因为它们来源于自然发生的可再生资源，并且在很大程度上对环境和生理无害。根据溶液中表面活性剂的浓度和温度的不同，烷基糖苷会聚集成各种聚集体，如球形胶束和层状双分子层。我们的方法监测染料的荧光信号，该染料以非常低的浓度掺入溶剂-表面活性剂混合物中。染料对其化学环境很敏感，并产生一种独特的信号，反映了现有聚集体的性质。该技术的一个重要优点是染料在不同表面活性剂聚集体中的荧光信号是相互独立的，因此可以同时检测到共存聚集体中的荧光信号。事实上，信号可以唯一地识别当前的聚集体，这使该技术具有新颖性和威力。将准备相图来说明作为浓度和温度的函数的聚集体。由于糖苷表面活性剂的所有实际和商业应用都严重依赖于表面活性剂相图的知识，因此该项目将提供准确和完整的信息，以便制备特定的聚集体。这个项目的一个特别有趣的方面是构建并比较水中表面活性剂的相图和离子液体中相同表面活性剂的相图。由于表面活性剂在离子液体中的行为研究是一个相对未开发的领域，我们对离子液体中糖苷的研究将对这些绿色溶剂体系中表面活性剂的现有文献做出重大贡献。由于精确相图的可用性对从材料到生物化学的许多学科都很重要，因此该项目具有广泛的跨学科影响的潜力。此外，这些调查的一个重要目标是培养有才华的本科生的研究方法，以便在研究生学习或工业中从事生产性职业。该项目将继续展示和加强在一所主要本科院校的联合首席研究员实验室进行有效的师生合作研究的可行性，从而在同行评审的期刊上发表论文，并在科学场所发表演讲。

This project supported by the Experimental Physical Chemistry Program employs a new approach to more quickly and accurately determine the behavior of an important class of "green" surfactants in various solvents. The surfactants known as alkyl glucosides are considered "green" as they are derived from naturally occurring and renewable resources and are largely environmentally and physiologically benign. Depending on the temperature and the surfactant concentration in solution, alkyl glucosides assemble into a variety of aggregates such as spherical micelles and lamellar bilayers. Our approach monitors the fluorescence signal of a dye that is incorporated in the solvent-surfactant mixtures at very low concentrations. The dye is sensitive to its chemical environment and yields a unique signal that reflects the nature of the aggregate(s) present. One important advantage of this technique is that the fluorescence signals of the dye in different surfactant aggregates are independent of each other, and thus the signals from coexisting aggregates can be detected simultaneously. The fact that the signals can uniquely identify the aggregates present gives this technique its novelty and power. Phase diagrams will be prepared to illustrate the aggregates present as a function of concentration and temperature. As all of the practical and commercial applications of glucoside surfactants depend critically on knowledge of surfactant phase diagrams, this project will provide accurate and complete information to enable preparation of specific aggregates. A particularly intriguing aspect of this project is to construct and then compare the phase diagrams of the surfactants in water with the phase diagrams of the same surfactants in ionic liquids. As the study of surfactant behavior in ionic liquids is a relatively unexplored area, our investigations of the glucosides in ionic liquids will make a significant contribution to the available literature on surfactants in these green solvent systems. Since the availability of accurate phase diagrams is important to many disciplines from materials to biochemistry, this project has the potential for broad interdisciplinary impact. Furthermore, an important objective of these investigations is the training of talented undergraduate students in the methods of research for productive careers in graduate studies or industry. The project will continue to demonstrate and enhance the feasibility of effective collaborative student-faculty research in the co-principal investigators' laboratories at a primarily undergraduate institution leading to publications in peer-reviewed journals and presentations at scientific venues.