Influence of stearic acid coating of the NaCl surface on the reactivity with NO2 under humidity
| Autor: | Myriam Moreau, Denis Petitprez, I. de Waele, J. Barbillat, Yeny A. Tobon, N. Nuns, Sophie Sobanska, Claude Bremard |
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| Přispěvatelé: | Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Institut des Molécules et de la Matière Condensée de Lille (IMMCL), Centrale Lille Institut (CLIL)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Sciences et Technologies, Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522 (PC2A), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Lille, Sciences et Technologies-Centrale Lille-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution 010504 meteorology & atmospheric sciences Chemistry Inorganic chemistry General Physics and Astronomy engineering.material 010402 general chemistry 01 natural sciences 0104 chemical sciences [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry chemistry.chemical_compound Adsorption Coating 13. Climate action Monolayer engineering Particle Reactivity (chemistry) Stearic acid Physical and Theoretical Chemistry Alkyl 0105 earth and related environmental sciences |
| Zdroj: | Physical Chemistry Chemical Physics Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2015, 17, pp.10963-10977. ⟨10.1039/c4cp05655h⟩ Physical Chemistry Chemical Physics, 2015, 17, pp.10963-10977. ⟨10.1039/c4cp05655h⟩ |
| ISSN: | 1463-9076 1463-9084 |
| DOI: | 10.1039/c4cp05655h⟩ |
| Popis: | In the atmosphere, sea salt aerosols, containing mainly NaCl, can accumulate fatty acids and undergo heterogeneous chemistry with atmospheric nitrogen oxides. The effect of stearic acid (SA) coating on the reactivity of the NaCl(100) surface with NO2 under humidity was studied by atomic force microscopy (AFM), Raman mapping and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to highlight processes occurring on NaCl surfaces. The vapor-deposition of SA on the NaCl surface generates heterogeneous coating with discontinuous monolayer islands. The SA molecules with all-trans conformation stick to the NaCl surface through -CO2H groups and are organized in parallel between them and nearly perpendicularly to the surface. The SA coating does not prevent the NaNO3 particle formation when the sample is exposed to NO2 under low humidity conditions. The initial abilities of the NaCl surface coated with SA to pick up NO2 from the gas phase are correlated with the fraction of bare NaCl area evidencing the spatially heterogeneous reactivity of the surface. The role of H2O in the NO2 uptake and the catalytic conversion of NaCl to NaNO3 is shown. Under humidity (RH = 50%), the H2O uptake by NaNO3 particles on the coated-NaCl surface is significantly more important than that adsorbed under analogous conditions without the presence of NaNO3 particles. This unusual water absorption initiates transitions (i) from solid NaNO3 particles to NaNO3 aqueous solution and (ii) from the SA monolayer with well-ordered all trans alkyl chains to the SA gel with completely disordered conformation. This mixed SA/NaNO3 layer on the particle surface may have significant consequences on the hygroscopic properties and reactivity of the sea salt aerosols in the atmosphere. |
| Databáze: | OpenAIRE |
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