Water induced recrystallization of monolayers sodium nitrate films on NaCl(100): Implications for the chemistry sea salt particles in the troposphere
- Univ. of California, Irvine, CA (United States)
X-ray photoelectron spectroscopy and transmission electron microscopy have been used to study the reaction of HNO{sub 3} with single crystal NaCl(100) and the effects of water vapor exposure on the nitrate films which are formed. Reactions of NO{sub y} species with sea salt particles may provide a substantial source of Cl atoms in the marine troposphere. Our experiments show that HNO{sub 3} reacts with NaCl(100) to form monolayer films of nitrate which passivates the surface. XPS and TEM experiments show that water vapor exposure following growth of monolayer nitrate films results in the dissolution of the nitrate followed by recrystallization to form 3-D crystallites. We have followed the recrystallization of the sodium nitrate over a wide range of water vapor pressures (from 0.05 Torr to 12 Torr). The deliquescence point of bulk sodium nitrate at room temperature is {approximately}75% relative humidity ({approximately}17.5 Tort). We observe facile dissolution and recrystallization of monolayer sodium nitrate at water vapor pressures well below the bulk deliquescence point.
- OSTI ID:
- 370170
- Report Number(s):
- CONF-960376--
- Country of Publication:
- United States
- Language:
- English
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