Study of Low Frequency Collective Modes of Hydrogen Bonded Liquids in Bulk Mixtures and at the Liquid/Solid Interface Using Time Domain THz and THz-SHG Spectroscopy

University Of California-Riverside, Riverside CA

Investigators

Abstract

Professor Harry Tom of the University of California Riverside is supported by the Analytical and Surface Chemistry Program to use terahertz spectroscopy to study hydrogen bonded liquids and the solid/liquid interface. Time-domain terahertz spectroscopy will be improved by extending the range to as low as 0.002 THz using instrumental and data analysis advances. Secondly the low frequency features will be analyzed using memory kernal formalism to extract collective molecular orientation, angular velocity, and potentially also cross-coupling strengths. These methods will be used to study ionic solutions as well as solutions of increasingly complex molecules leading up to biomolecules such as DNA. Lastly, THz pump and time-resolved second harmonic generation will be developed for the study of solid/liquid interfaces (namely, phenol derivatives adsorbed at the water/silica interface). Terahertz spectroscopy has only recently come on the scene as a new method for probing very low frequency motions, and this new information promises to be of importance in understanding condensed liquids, interfaces, as well as biological media.