@article {2048,
	title = {Reactive uptake of N2O5 on aqueous H2SO4 solutions coated with 1-component and 2-component monolayers},
	journal = {Journal of Physical Chemistry A},
	volume = {112},
	number = {20},
	year = {2008},
	note = {ISI Document Delivery No.: 301OHTimes Cited: 16Cited Reference Count: 90Cosman, L. M. Bertram, A. K.},
	month = {May},
	pages = {4625-4635},
	type = {Article},
	abstract = {Reactive uptake of N2O5 on aqueous sulfuric acid solutions was studied in the presence of 1-component (octadecanol) and 2-component (octadecanol + phytanic acid) monolayers. In the 1-component monolayer experiments, the reactive uptake coefficient depended strongly on the molecular surface area of the surfactant. Also, the 1-component monolayer showed significant resistance to mass transfer even when the fractional surface coverage of the surfactant was less than 1. For example, a monolayer of I-octadecanol with a fractional surface coverage of 0.75 decreased the reactive uptake coefficient by a factor of 10. This is consistent with previous studies. In the 2-component monolayer experiments, the reactive uptake coefficient depended strongly on the composition of the monolayer. When the monolayer contained only straight-chain molecules (1-octadecanol), the reactive uptake coefficient decreased by a factor of 42 due to the presence of the monolayer. However, when the monolayer contained 0.20 mole fraction of a branched surfactant (phytanic acid) the reactive uptake coefficient only decreased by a factor of 2. Hence, a small amount of branched surfactant drastically changes the overall resistance to reactive uptake. Also, our results show that the overall resistance to reactive uptake of 2-component monolayers can be predicted reasonably accurately by a model that assumes the resistances to mass transfer can be combined in parallel.},
	keywords = {AIR-WATER-INTERFACE, ATMOSPHERIC AEROSOL, EVAPORATION RESISTANCES, FILMS, HETEROGENEOUS HYDROLYSIS, MIXED MONOLAYERS, ORGANIC, REACTION PROBABILITIES, SEA-SALT, SULFURIC-ACID PARTICLES, TRANSPORT PROPERTIES},
	isbn = {1089-5639},
	url = {<Go to ISI>://000255905000015},
	author = {Cosman, L. M. and Bertram, A. K.}
}
@article {1516,
	title = {Crystallization of aqueous ammonium sulfate particles internally mixed with soot and kaolinite: Crystallization relative humidities and nucleation rates},
	journal = {Journal of Physical Chemistry A},
	volume = {110},
	number = {28},
	year = {2006},
	note = {ISI Document Delivery No.: 063EXTimes Cited: 12Cited Reference Count: 70Pant, Atul Parsons, Matthew T. Bertram, Allan K.},
	month = {Jul},
	pages = {8701-8709},
	type = {Article},
	abstract = {Using optical microscopy, we investigated the crystallization of aqueous ammonium sulfate droplets containing soot and kaolinite, as well as the crystallization of aqueous ammonium sulfate droplets free of solid material. Our results show that soot did not influence the crystallization RH of aqueous ammonium sulfate particles under our experimental conditions. In contrast, kaolinite increased the crystallization RH of the aqueous ammonium sulfate droplets by approximately 10\%. In addition, our results show that the crystallization RH of aqueous ammonium sulfate droplets free of solid material does not depend strongly on particle size. This is consistent with conclusions made previously in the literature, based on comparisons of results from different laboratories. From the crystallization results we determined the homogeneous nucleation rates of crystalline ammonium sulfate in aqueous ammonium sulfate droplets and the heterogeneous nucleation rates of crystalline ammonium sulfate in aqueous ammonium sulfate particles containing kaolinite. Using classical nucleation theory and our experimental data, we determined that the interfacial tension between an ammonium sulfate critical nucleus and an aqueous ammonium sulfate solution is 0.064 +/- 0.003 J m(-2) (in agreement with our previous measurements), and the contact angle between an ammonium sulfate critical nucleus and a kaolinite surface is 59 +/- 2. On the basis of our results, we argue that soot will not influence the crystallization RH of aqueous ammonium sulfate droplets in the atmosphere, but kaolinite can significantly modify the crystallization RH of atmospheric ammonium sulfate droplets. As an example, the CRH50 ( the relative humidity at which 50\% of the droplets crystallize) ranges from about 41 to 51\% RH when the diameter of the kaolinite inclusion ranges from 0.1 to 5 mu m. For comparison, the CRH50 of aqueous ammonium sulfate droplets (0.5 Am diameter) free of solid material is approximately 34.3\% RH under atmospheric conditions.},
	keywords = {AEROSOL-PARTICLES, ATMOSPHERIC AEROSOL, deliquescence, HETEROGENEOUS NUCLEATION, HYGROSCOPIC GROWTH, MINERAL DUST, ORGANIC-COMPOUNDS, PHASE-TRANSITIONS, TROPOSPHERIC AEROSOLS, WATER-UPTAKE},
	isbn = {1089-5639},
	url = {<Go to ISI>://000239001600013},
	author = {Pant, A. and Parsons, M. T. and Bertram, A. K.}
}
@article {956,
	title = {Deliquescence and crystallization of ammonium sulfate particles internally mixed with water-soluble organic compounds},
	journal = {Journal of Physical Chemistry A},
	volume = {108},
	number = {52},
	year = {2004},
	note = {ISI Document Delivery No.: 882FPTimes Cited: 38Cited Reference Count: 66},
	month = {Dec},
	pages = {11600-11608},
	type = {Article},
	abstract = {The deliquescence and crystallization of ammonium sulfate particles internally mixed with water-soluble organic material have been studied, restricted to an organic mass fraction of less than 0.6. The organic species used were malonic acid, glycerol, levoglucosan (1,6-anhydro-beta-D-glucopyranose), and Suwannee River fulvic acid. Our deliquescence results for systems with malonic acid and fulvic acid are in agreement with existing literature values. Glycerol deliquescence results are slightly lower than previous measurements. The levoglucosan results are the first of this kind. Total deliquescence relative humidities for the different systems are the same within the uncertainty of the measurements when the organic mole fraction is less than approximately 0.35. At an organic mole fraction of 0.6, the maximum deviation of total deliquescence relative humidities between the systems is approximately 10\% relative humidity. We show that thermodynamic calculations based on a simplified version of a model recently proposed by Clegg et al. (J. Aerosol Sci. 2001, 32, 713)1 are in agreement with measured values of deliquescence relative humidity up to an organic mole fraction of approximately 0.4 for most of the systems studied. The crystallization relative humidity (CRH) of mixed systems of ammonium sulfate with malonic acid, glycerol, or levoglucosan decreases significantly from the CRH of pure ammonium sulfate when the organic mole fraction is greater than about 0.25. This is in contrast to our previous study with glutaric acid where CRH remained close to CRH of pure ammonium sulfate up to a glutaric acid mole fraction of 0.4. CRH values are shown to vary depending on the type of,organic present. In terms of atmospheric implications, we estimate that organics, on average, are only a minor perturbation on the deliquescence relative humidity of the pure inorganic particles, whereas the organics, on average, may decrease the CRH of pure inorganic particles significantly and this effect depends on the type of organic material.},
	keywords = {ATMOSPHERIC AEROSOL, BLACK CARBON, DICARBOXYLIC-ACIDS, FINE AEROSOL, HUMIC-LIKE SUBSTANCES, HYGROSCOPIC PROPERTIES, MODEL, PHASE-TRANSITIONS, PHYSICAL, RELATIVE-HUMIDITY, STATE},
	isbn = {1089-5639},
	url = {<Go to ISI>://000225924800016},
	author = {Parsons, M. T. and Knopf, D. A. and Bertram, A. K.}
}
