| Abstract
| - Organic compounds are a significant component of tropospheric aerosols. In the present study, 1-methylnaphthalene was selected as a surrogate for aromatic hydrocarbons (PAHs) found in tropospheric aerosols.Mass accommodation coefficients (α) on 1-methylnaphthalene were determined as a function of temperature(267 K to 298 K) for gas-phase m-xylene, ethylbenzene, butylbenzene, α-pinene, γ-terpinene, p-cymene, and2-methyl-2-hexanol. The gas uptake studies were performed with droplets maintained under liquid−vaporequilibrium conditions using a droplet train flow reactor. The mass accommodation coefficients for all of themolecules studied in these experiments exhibit negative temperature dependence. The upper and lower valuesof α at 267 and 298 K respectively are as follows: for m-xylene 0.44 ± 0.05 and 0.26 ± 0.03; for ethylbenzene0.37 ± 0.03 and 0.22 ± 0.04; for butylbenzene 0.47 ± 0.06 and 0.31 ± 0.04; for α-pinene 0.47 ± 0.07 and0.10 ± 0.05; for γ-terpinene 0.37 ± 0.04 and 0.12 ± 0.06; for p-cymene 0.74 ± 0.05 and 0.36 ± 0.07; for2-methyl-2-hexanol 0.44 ± 0.06 and 0.29 ± 0.06. The uptake measurements also yielded values for theproduct HDl1/2 for most of the molecules studied (H = Henry's law constant, Dl = liquid-phase diffusioncoefficient). Using calculated values of Dl, the Henry's law constants (H) for these molecules were obtainedas a function of temperature. The H values at 298 K in units 103 M atm-1 are as follows: for m-xylene (0.48± 0.05); for ethylbenzene (0.50 ± 0.08); for butylbenzene (3.99 ± 0.93); for α-pinene (0.53 ± 0.07); forp-cymene (0.23 ± 0.07); for 2-methyl-2-hexanol (1.85 ± 0.29).
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