FTDS studies of vaporization kinetics of ice near its melting point^1,2.

 

By taking advantage of a unique substrate geometry and a novel combination of FTDS and SC techniques we conducted the first direct measurements of the absolute vaporization rate of polycrystalline D₂O and H₂O ice at temperatures from -30 to 0°C. Furthermore, using results of FTDS experiments with sandwich-like H₂O¹⁶/ H₂O¹⁸/H₂O¹⁶, we were able to infer the absolute vaporization rate of single crystal ice.

 

In addition to providing concrete data for applied research, these studies also resulted in surprising insight into the fundamentals of vaporization of ice and other volatile solids. For example, as we argue in our publications, the observed vaporization kinetics are inconsistent with the simple mobile precursor model due to progressive surface roughening or premelting of ice near its normal melting point. Thus, our work demonstrates that uptake and release of gases on an ice/vapor interface at temperatures near ice melting point may be equally or even more complex as that on liquid surfaces.  Because the uptake and release of gases on ice is likely to depend on the ice surface morphology, theoretical descriptions of these processes may require a new formalism that takes into account possible surface phase transitions at various temperatures.

 

 

 

 

 

References:

 

1. Haiping Lu, Stephanie A. McCartney, M. Chonde, D. Smyla, and Vlad Sadtchenko, J. Chem. Phys. 125, 044709 (2006)

 

1. Vlad Sadtchenko, Brindza M, Chonde M, B. Palmore, R. Eom., J. Chem. Phys. 121, 11980 (2004)