Solvatochromic Studies of Solvated Surface Phases

这个基金是在分析和表面化学的一般领域和在分离科学的子领域。Sarah Rutan教授将研究液相色谱中固定相的结构。通过在特定溶剂环境中使用分子探针的光谱学组合，她将确定系统的所谓溶剂致变色参数。通过这种方法可以确定液固界面上分子种类的基本结构和反应性。更好地理解分子相互作用的机制，从而导致流动中分子种类的分离。探针分子与液相色谱固定相之间的相互作用将被确定。光学（紫外-可见和红外光谱）波段位移将被测量和分析，以消除溶液相位干扰。双极性-极化性、氢键酸度和碱度将使我们能够理解基于溶剂的反应性和分离和其他液固界面系统的吸附效应。特定的溶剂系统将包括甲醇，乙腈和四氢呋喃-水混合物，通常用于高效液相色谱。将研究碳氢化合物和苯基改性二氧化硅以及未改性二氧化硅。探针分子包括一系列硝基苯胺染料，通常用于探测溶剂溶质相互作用。进行多组分分析和消除液相效应的独特能力将使目前对溶液中分子水平吸附动力学的理解有所提高。

This grant is in the general field of analytical and surface chemistry and in the subfield of separations science. Professor Sarah Rutan will study the structure of stationary phases used in liquid chromatography. By using a combination of optical spectroscopy of molecular probes in specific solvent environments she will determine the so-called solvatochromic parameters of the system. From this approach the fundamental structure and reactivity of the molecular species at the liquid solid interface can be determined. A better understanding of the mechanisms of molecular interactions which give rise to separations of molecular species in flow will result. Molecular interactions between probe molecules and liquid chromatographic stationary phases will be determined. Optical (uv-visible and infrared spectroscopic band shifts will be measured and analyzed to remove solution phase interferences. Dipolarity-polarizability, hydrogen bond acidity and basicity will allow an understanding of solvent based reactivity and adsorption effects underlying separations and other liquid solid interfacial systems. The particular solvent systems will include methanol, acetonitrile and tetrahydrofuran - water mixtures commonly used in high performance liquid chromatography. Hydrocarbon and phenyl modified silica as well as unmodified silica will be studied. The probe molecules include a series of nitroaniline dyes commonly used to probe solvent solute interactions. Unique capabilities to perform multicomponent analysis and eliminate the contributions of liquid phase effects will allow improvement over the current level of understanding of the dynamics of adsorption at the molecular level in solution.