The role of tropospheric ice surfaces in the elimination of the CFC substitute, trifluoroethanol

Phys Chem Chem Phys. 2012 Apr 7;14(13):4425-32. doi: 10.1039/c2cp23553f. Epub 2012 Feb 24.

Abstract

This work provides uptake results of CF(3)CH(2)OH on ice over the temperature range 203-223 K using a coated wall flow tube coupled to mass spectrometric detection. For experiments over pure ice, the adsorption was fully reversible and the data could be described in terms of the Langmuir isotherm for the range of concentrations and temperatures studied. For this temperature range, ΔH°(ads) = -46 ± 16 kJ mol(-1) was obtained (error is 2σ + 5%). For experiments on doped ice with nitric acid over the temperature range 203-223 K, the number of adsorbed molecules was slightly lower than over pure ice. At temperatures above 231 K, the extent of the reversible uptake of CF(3)CH(2)OH is enhanced in the presence of nitric acid due to coexistence of a liquid solution phase. Under such conditions the obtained solubility data follow Henry's law. Although pure ice and acid doped water surfaces do not permanently scavenge CF(3)CH(2)OH, the partitioning of CF(3)CH(2)OH between the gas phase and aqueous condensed phases may play a role as reservoirs or as a means of transport in the troposphere.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Ice*
  • Surface Properties
  • Thermodynamics
  • Trifluoroethanol / chemistry*

Substances

  • Ice
  • Trifluoroethanol