naa a22 4500 528787217 20180924065503.0 cr unu---uuuuu 180924s2010 xx s 000 0 eng 10.3929/ethz-b-000028133 doi 10.5194/acp-10-11753-2010 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/28133 The vapor pressures and activities of dicarboxylic acids reconsidered: the impact of the physical state of the aerosol [Elektronische Daten] [Vacharaporn Soonsin, Alessandro A. Zardini, Claudia Marcolli, Andreas Zuend, Ulrich; id_orcid 0000-0003-4958-2657 Krieger] Atmos. chem. phys. Open access ethresearch We present vapor pressure data of the C2 to C5 dicarboxylic acids deduced from measured evaporation rates of single levitated particles as both, aqueous droplets and solid crystals. The data of aqueous solution particles over a wide concentration range allow us to directly calculate activities of the dicarboxylic acids and comparison of these activities with parameterizations reported in the literature. The data of the pure liquid state acids, i.e. the dicarboxylic acids in their supercooled melt state, exhibit no even-odd alternation in vapor pressure, while the acids in the solid form do. This observation is consistent with the known solubilities of the acids and our measured vapor pressures of the supercooled melt. Thus, the gas/particle partitioning of the different dicarboxylic acids in the atmosphere depends strongly on the physical state of the aerosol phase, the difference being largest for the even acids. Our results show also that, in general, measurements of vapor pressures of solid dicarboxylic acids may be compromised by the presence of polymorphic forms, crystalline structures with a high defect number, and/or solvent inclusions in the solid material, yielding a higher vapor pressure than the one of the thermodynamically stable crystalline form at the same temperature. Creative Commons Attribution 3.0 Unported http://creativecommons.org/licenses/by/3.0 ethresearch Soonsin Vacharaporn joint author Zardini Alessandro A. joint author Marcolli Claudia joint author Zuend Andreas joint author Krieger Ulrich; id_orcid 0000-0003-4958-2657 joint author Atmospheric Chemistry and Physics Munich : European Geophysical Society 10 (23), pp. 11753-11767 1680-7375 http://hdl.handle.net/20.500.11850/28133 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/28133 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Soonsin Vacharaporn joint author ETHRESEARCH 700 1- Zardini Alessandro A. joint author ETHRESEARCH 700 1- Marcolli Claudia joint author ETHRESEARCH 700 1- Zuend Andreas joint author ETHRESEARCH 700 1- Krieger Ulrich; id_orcid 0000-0003-4958-2657 joint author ETHRESEARCH 773 0- Atmospheric Chemistry and Physics Munich : European Geophysical Society 10 (23), pp. 11753-11767 1680-7375 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access