@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 {957,
	title = {Deliquescence of malonic, succinic, glutaric, and adipic acid particles},
	journal = {Journal of Geophysical Research-Atmospheres},
	volume = {109},
	number = {D6},
	year = {2004},
	note = {ISI Document Delivery No.: 809FPTimes Cited: 32Cited Reference Count: 46},
	month = {Mar},
	pages = {8},
	type = {Article},
	abstract = {In order to understand and predict the role of organic particles in the atmosphere their deliquescence behavior must be understood. Using an optical microscope coupled to a flow cell, we investigated the deliquescence of malonic, succinic, glutaric, and adipic acid particles with sizes ranging from 2 to 40 mm. Deliquescence relative humidities were determined for temperatures ranging from 293 to 243 K. Over this temperature range both succinic acid and adipic acid deliquesced at approximately 100\% relative humidity, whereas malonic acid and glutaric acid deliquesced at significantly lower relative humidities. These results are generally in good agreement with previous studies and are within 3\% of calculations based on the UNIQUAC (universal quasi-chemical) Functional Group Activity Coefficients (UNIFAC) model and recently published interaction parameters. Our studies also include measurements at temperatures below the eutectic temperatures. At these temperatures, ice did not nucleate; rather the particles underwent deliquescence to form metastable solution droplets. This indicates that solid dicarboxylic acids are not good ice nuclei above 243 K and hence will probably not play a role in ice cloud formation at these temperatures.},
	keywords = {AEROSOL, AEROSOL PHASE, AMAZON BASIN, AMMONIUM-SULFATE, atmospheric chemistry, ATMOSPHERIC PARTICLES, CIRRUS CLOUD FORMATION, deliquescence, dicarboxylic acid, DICARBOXYLIC-ACIDS, HYGROSCOPIC GROWTH, ice, NUCLEATION, optical microscopy, PHASE-TRANSITIONS, STRATOSPHERIC TEMPERATURES, WATER},
	isbn = {0148-0227},
	url = {<Go to ISI>://000220622900002},
	author = {Parsons, M. T. and Mak, J. and Lipetz, S. R. and Bertram, A. K.}
}
