Chemical composition of surface films on glass windows and implications for atmospheric chemistry

Lam, Buuan; Diamond, Miriam L.; Simpson, André J.; Makar, Paul A.; Truong, Jennifer; Hernandez-Martinez, Nadia A.

doi:10.1016/j.atmosenv.2005.07.057

Cited by 100 publications

(189 citation statements)

References 35 publications

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“…One chamber contains silica (SiO 2 ) powder pressed into pellets, which provide large surface areas for the heterogeneous chemistry, whereas the second, empty chamber acts as a bypass. Silica powder is selected to mimic silicate-rich urban surfaces and some of the oxide surfaces present in mineral dust (8,22,23), which are important substrates for heterogeneous tropospheric chemistry. Fig.…”

Section: ]mentioning

confidence: 99%

Chlorine activation indoors and outdoors via surface-mediated reactions of nitrogen oxides with hydrogen chloride

Raff

Njegic

Chang

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

113

182

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Gaseous HCl generated from a variety of sources is ubiquitous in both outdoor and indoor air. Oxides of nitrogen (NO y ) are also globally distributed, because NO formed in combustion processes is oxidized to NO 2 , HNO 3 , N 2 O 5 and a variety of other nitrogen oxides during transport. Deposition of HCl and NO y onto surfaces is commonly regarded as providing permanent removal mechanisms. However, we show here a new surface-mediated coupling of nitrogen oxide and halogen activation cycles in which uptake of gaseous NO 2 or N 2 O 5 on solid substrates generates adsorbed intermediates that react with HCl to generate gaseous nitrosyl chloride (ClNO) and nitryl chloride (ClNO 2 ), respectively. These are potentially harmful gases that photolyze to form highly reactive chlorine atoms. The reactions are shown both experimentally and theoretically to be enhanced by water, a surprising result given the availability of competing hydrolysis reaction pathways. Airshed modeling incorporating HCl generated from sea salt shows that in coastal urban regions, this heterogeneous chemistry increases surface-level ozone, a criteria air pollutant, greenhouse gas and source of atmospheric oxidants. In addition, it may contribute to recently measured high levels of ClNO 2 in the polluted coastal marine boundary layer. This work also suggests the potential for chlorine atom chemistry to occur indoors where significant concentrations of oxides of nitrogen and HCl coexist.

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Section: ]mentioning

confidence: 99%

Chlorine activation indoors and outdoors via surface-mediated reactions of nitrogen oxides with hydrogen chloride

Raff

Njegic

Chang

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

113

182

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“…SAMs formed by reaction of trichloroalkylsilanes on SiO x surfaces, for example on the thin oxide layer on silicon, may be particularly relevant to reactions of organic compounds on dust and on building materials for which silicates can be major components. 208,[238][239][240][241][242][243][244] Another advantage is that silicon crystals are readily available which can be used to make real-time measurements of the oxidation of SAMs attached to their surface using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. In one study, 221 ozonolysis of terminal alkene SAMs with 3-and 8-carbon atoms was observed to give CQO groups as products as expected, at least a portion of which were in the form of carboxylic acids that could be converted to carboxylates by reaction with gaseous NH 3 .…”

Section: This Journal Is C the Owner Societies 2009mentioning

confidence: 99%

Reactions at surfaces in the atmosphere: integration of experiments and theory as necessary (but not necessarily sufficient) for predicting the physical chemistry of aerosols

Finlayson-Pitts

2009

Phys. Chem. Chem. Phys.

229

272

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“…[1][2][3][4][5][6][7] Airborne particles also have a complex composition, with organic compounds as major components. [8][9][10][11] The chemistry associated with particles is of major interest because they are known to have adverse impacts on climate, human health and the chemistry of the atmosphere.…”

Section: Introductionmentioning

confidence: 99%

“…The direct and indirect effects of particles on the climate are responsible for the largest uncertainties in predicting climate change. 14 Oxidation of organics on surfaces and in or on airborne particles is initiated by reactions with OH, O 3 and NO 3 . 13 The kinetics and mechanisms of organic oxidations in the gas phase have been extensively studied and are reasonably well understood, 13,[15][16][17][18] but much less is known about the reactions of gas phase oxidants with such condensed phase organics.…”

Section: Introductionmentioning

confidence: 99%

Reaction of gas phase OH with unsaturated self-assembled monolayers and relevance to atmospheric organic oxidations

Moussa

Finlayson-Pitts

2010

Phys. Chem. Chem. Phys.

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The kinetics and mechanisms of the reaction of gas phase OH radicals with organics on surfaces are of fundamental chemical interest, as well as relevant to understanding the degradation of organics on tropospheric surfaces or when they are components of airborne particles. We report here studies of the oxidation of a terminal alkene self-assembled monolayer (7-octenyltrichlorosilane, C8Q SAM) on a germanium attenuated total reflectance crystal by OH radicals at a concentration of 2.1 Â 10 5 cm À3 at 1 atm total pressure and 298 K in air. Loss of the reactant SAM and the formation of surface products were followed in real time using infrared spectroscopy. From the rate of loss of the CQC bond, a reaction probability within experimental error of unity was derived. The products formed on the surface include organic nitrates and carbonyl compounds, with yields of 10 AE 4% and r7 AE 4%, respectively, and there is evidence for the formation of organic products with C-O bonds such as alcohols, ethers and/or alkyl peroxides and possibly peroxynitrates. The yield of organic nitrates relative to carbonyl compounds is higher than expected based on analogous gas phase mechanisms, suggesting that the branching ratio for the RO 2 + NO reaction is shifted to favor the formation of organic nitrates when the reaction occurs on a surface. Water uptake onto the surface was only slightly enhanced upon oxidation, suggesting that oxidation per se cannot be taken as a predictor of increased hydrophilicity of atmospheric organics. These experiments indicate that the mechanisms for the surface reactions are different from gas phase reactions, but the OH oxidation of surface species will still be a significant contributor to determining their lifetimes in air.

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Chemical composition of surface films on glass windows and implications for atmospheric chemistry

Cited by 100 publications

References 35 publications

Chlorine activation indoors and outdoors via surface-mediated reactions of nitrogen oxides with hydrogen chloride

Chlorine activation indoors and outdoors via surface-mediated reactions of nitrogen oxides with hydrogen chloride

Reactions at surfaces in the atmosphere: integration of experiments and theory as necessary (but not necessarily sufficient) for predicting the physical chemistry of aerosols

Reaction of gas phase OH with unsaturated self-assembled monolayers and relevance to atmospheric organic oxidations

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