Determination of the Specific Surface Area of Snow Using Ozonation of 1,1-Diphenylethylene
| Authors | |
|---|---|
| Year of publication | 2011 |
| Type | Article in Periodical |
| Magazine / Source | Environmental Science & Technology |
| MU Faculty or unit | |
| Citation | |
| Web | http://pubs.acs.org/doi/abs/10.1021/es202922k |
| Doi | http://dx.doi.org/10.1021/es202922k |
| Field | Organic chemistry |
| Keywords | Photochemistry; snow; ozonolysis |
| Description | We measured the kinetics of ozonation reaction of 1,1-diphenylethylene (DPE) in artificial snow, produced by shock freezing of DPE aqueous solutions sprayed into liquid nitrogen. It was demonstrated that most of the reactant molecules are in direct (productive) contact with gaseous ozone, thus the technique produces snow with organic molecules largely ejected to the surface of snow grains. The kinetic data were used to evaluate the snow specific surface area (70 cm2 g–1). This number is a measure of the availability of the molecules on the surface for chemical reaction with gaseous species. The results are consistent with the Langmuir–Hinshelwood type reaction mechanism. For typical atmospheric ozone concentrations in polar areas (20 ppbv), the estimated half-life of DPE, representing environmentally relevant compounds such as alkenes on the surface of snow grains is 5 days at sub-monolayer coverages and –15 oC. |
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