Molecular Interaction with Colloidal Surfaces Probed By Nonlinear Light Scattering

化学系的大分子、超分子和纳米化学（MSN）项目将支持天普大学戴海龙教授的研究项目。戴教授和他的学生将开发和应用非线性光散射方法来表征胶体物体表面的结构和能量学，从而在定量描述胶体表面分子相互作用的基础上建立对胶体性质的基本理解。戴教授和他的学生将在严格的理论建模的基础上，利用光学二次谐波产生（SHG）光谱来确定吸附在胶体颗粒上的分子的几何形状；利用SHG光谱确定溶剂离子强度和离子特异性对分子在胶体表面吸附、乳液形成和分子通过生物细胞转运的影响；并演示了使用窄带宽红外激光源对胶体表面官能团的振动光谱进行和频生成（SFG）。本研究所建立的胶体表面微观表征的新实验能力，将极大地促进基础胶体和表面科学以及细胞膜研究的发展。所开发的技术也可用于监测涉及胶体系统的各种工业过程。所获得的知识将直接影响诸如涂层材料、太阳能电池、药物测试分析和石油加工等技术。该项目将为希望在纳米科学和纳米技术方面进行培训的学生，包括来自代表性不足群体的学生提供良好的培训机会。

The Macromolecular, Supramolecular and Nanochemistry (MSN) program of the Division of Chemistry will support the research program of Prof. Hai-Lung Dai of Temple University. Prof. Dai and his students will develop and apply nonlinear light scattering method to characterize the structure and energetics at the surface of colloidal objects so that a fundamental understanding of colloidal properties can be established based on quantitative descriptions of molecular interactions at colloidal surfaces. Prof. Dai and his students will use optical second harmonic generation (SHG) spectroscopy to determine the geometry of molecules adsorbed on colloidal particles based on rigorous theoretical modeling; use SHG spectroscopy to define the effects of solvent ionic strength and ion specificity on molecular adsorption on colloidal surface, formation of emulsion, and molecular transport through biological cells; and demonstrate Sum Frequency Generation (SFG) using narrow bandwidth IR laser source for vibrational spectroscopy of functional groups at colloidal surfaces. The new experimental capabilities for microscopic characterization of the colloidal surface to be developed in this study will be highly beneficial for the advancement of fundamental colloidal and surface sciences and cell membrane research. The techniques developed may also be used for monitoring a wide variety of industrial processes involving colloidal systems. The knowledge acquired will directly impact on technologies such as coating materials, solar cells, drug testing assays and petroleum processing. The project will provide excellent training opportunities to students, including students from underrepresented groups, who wish to train in nanoscience and nanotechnology.