Master of Science in Chemical Engineering (MSChE)
Green Leaf Volatiles (GLVs) is a class of vegetation emissions whose release is greatly enhanced in the event of thermal or mechanical stress. These oxygenated hydrocarbons that have been identified as a potential source of Secondary Organic Aerosols (SOA) via aqueous oxidation. The physico-chemical properties of GLVs are vital to understanding their fate and transport in the atmosphere, but few experimental data are available. We studied the aqueous solubility, 1-Octanol/Water Partition Coefficient, and Henry’s Constant (KH) of five GLVs at 25&176;C: methyl jasmonate, methyl salicylate, 2-methyl-3-buten-2-ol, cis-3-hexen-1-ol, and cis-3-hexenyl acetate. Henry’s constant was additionally measured at 30&176;C & 35&176;C, and also in the presence of fog water’s common ion compounds with ionic strengths of 0.01 M and 1 M. Experimental values when available from literature are presented, as well as estimations using group and bond contribution methods and property-specific correlations. Estimations are compared to the measured values. The large Henry’s constant of methyl jasmonate (8091 &177; 1121 M/atm) made it the most significant GLV for aqueous phase photochemistry. The HENRYWIN program’s bond contribution method from the Estimation Programs Interface Suite produced the best estimate of the Henry’s Constant for GLVs. The best estimate of 1-Octanol/Water Partition Coefficient and Solubility came from correlating an experimental value of one to find the other. The Henry’s Constant values were used to determine the air-water and air-surface interface partition coefficients. Calculations using these partition coefficients showed the percentage of mols of four GLVs residing at the air-water interface of a fog droplet is significant compared to the bulk. Finally, the scavenging efficiency is calculated for each GLV indicating aqueous phase processing will be important for MeJa.
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Vempati, Harsha Satyanarayana, "Physico-Chemical Properties of Green Leaf Volatiles" (2014). LSU Master's Theses. 2140.
Valsaraj, Kalliat T