Spectroscopic and Simulation Studies of Ice Surface Interactions with Intermediate and Strong Adsorbates: Physics and Chemistry of Molecular Nanoparticles

Oklahoma State University, Stillwater OK

Investigators

Abstract

Paul Devlin of Oklahoma State University is supported by a grant from the Experimental Physical Chemistry Program to perform experimental and theoretical studies on the structure and dynamics of free-standing ice using Fourier transform-infrared spectroscopy of nanocrystals and Grand Canonical Monte Carlo calculations. This work is giving information on the strengths of bonds between water molecules and the nature of the dangling, unsatisfied surface bonds. In detail, he is study (i) the interaction the surface of ice with both strong (ammonia, ethylene oxide, methanol, small ethers, strong acids) and intermediate strength (sulfur dioxide, hydrogen sulfide and cyanide, ethylene) absorbates, (ii) the quantitative kinetics of conversion of ice nanocrystals to acid hydrates, (iii) the catalytic role of small ether molecules in aiding the conversion of ice to clathrate hydrates and (iv) an exploration of the chemistry of organic nanoparticles in three dimensional arrays. Several stages are involved in these interactions including initial absorption, insertion of adsorbed molecules into weak hydrogen bonds, surface relaxation and subsurface relaxation or formation of the hydrate phase. These studies will give a more detailed understanding of the nature of the surface of ice and the mechanisms by which different molecules absorb strongly and weakly onto ice nanocrystals. The work has broad applications to the role of ice particles in the destruction of stratospheric ozone, their significance in the diurnal variations of the atmospheres of the icy moons of Jupiter, the chemistry on the ice mantles of interstellar dust particles and the control of hydrated species in fuel science.