Molecular Interaction with Colloidal Surfaces Probed By Nonlinear Light Scattering

Temple University, Philadelphia PA

Investigators

Abstract

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.