Even−Odd Alternation of Evaporation Rates and Vapor Pressures of C3−C9 Dicarboxylic Acid Aerosols

Abstract

Aliphatic straight-chain dicarboxylic acids have been identified as common water-soluble organic components of atmospheric aerosols. To model the partitioning of such compounds between gas and particle phase in the atmosphere, information about their vapor pressures is essential. In this work, vapor pressures of C3-C9 dicarboxylic acids are derived from measured evaporation rates of submicron aerosols over the temperature range of 290-314 K using the tandem differential mobility analyzer technique. Vapor pressures obtained from the experimental data were as follows: log(p°m alonic , Pa) ) -4822 K/T + 12.9, log(p°s uccinic , Pa) ) -7196.8 K/T + 19.8, p°g lutaric (296 K) ) 6.7 × 10 -4 Pa, log(p°a dipic , Pa) ) -8065.0 K/T + 22.2, log(p°p imelic , Pa) ) -7692.8 K/T + 21.8, log(p°s uberic , Pa) ) -9629.4 K/T + 26.5, and log(p°a zelaic , Pa) ) -7968.7 K/T + 21.7. Vapor pressures of C3-C9 dicarboxylic acids are shown to alternate strongly with the parity of the number of carbon atoms. Higher vapor pressures of the odd acids fit the less stable crystal structure, the propensity of polymorphism in the odd acids, and the evolution of melting temperatures. Results are compared with available literature data.

Piezoelectric crystal microbalance measurements of enthalpy of sublimation of C<sub>2</sub>–C<sub>9</sub> dicarboxylic acids

“…Our results are quite low compared to those measured by Bilde et al (2003) (within 9 % for the adipic acid), who demonstrate the capability of the tandem differential mobility analyser (TDMA) technique to measure the vapour pressures of submicron aerosol particles at solid-state structure. The results of evaporation rates were measured over the temperature range 17-41 • C. In the TDMA technique, the major source of error was based on the sensitivity analysis (a conservative uncertainty and systematic errors were considered on vapour pressures).…”

“…Our results were compared with previous works (Table 4) that use a similar effusion method and theoretical approach (i.e. Albyn 2001;Booth et al, 2009;Ribeiro da Silva et al, 2001) and with works that analyse the same dicarboxylic acids used in our study (Chattopadhyay et al, 2007;Bilde et al, 2003 …”

“…quality of our method and the validity of our results, the enthalpies of sublimation have been compared with the results obtained by previous works. In the comparison, we will take into account the different boundary conditions (initial temperatures and working pressures) of the different procedures (Table 4): TDMA (Bilde et al, 2003), Knudsen mass loss (Ribeiro da Silva et al, 1999), KEMS (Booth et al, 2009), TDPBMS (Chattopadhyay andZiemann, 2007), the effusion method, EM (Davies and Thomas, 1960;Granovskaya, 1948), and E-1559 Method B (Albyn, 2001).…”

“…the thermal desorption particle beam mass spectrometry (TDPBMS) method (Chattopadhyay and Ziemann, 2007), the Knudsen effusion mass-loss method (Ribeiro da Silva et al, 2001), Knudsen effusion mass spectrometry (KEMS) (Booth et al, 2009), the tandem differential mobility analyser (TDMA) technique (Bilde et al, 2003), and the effusion method (Davies and Thomas, 1960;Granovskaya, 1948). Discrepancies between results obtained by the different methodologies were found to be up to 2 orders of magnitude, and this makes the acids' characterization even more difficult.…”

Gas–particle partitioning of atmospheric aerosols: interplay of physical state, non-ideal mixing and morphology

“…D g,Z i of organic components are assumed to be 0.05 cm 2 s À1 . 69,70 Adsorption and desorption fluxes ( J ads,Z i , J des,Z i ) are described as,…”