Potential of mean force (PMF) calculations and molecular dynamics (MD) simulations were performed to investigate the properties of oil n-alkanes [i.e., n-pentadecane (C15), n-icosane (C20) and n-triacontane (C30)], as well as several surfactant species [i.
View Article and Find Full Text PDFOil spills in the deep-sea environment such as the 2010 Deep Water Horizon oil spill in the Gulf of Mexico release vast quantities of crude oil into the sea-surface environment. Various investigators have discussed the marine transport and fate of the oil into different environmental compartments (air, water, sediment, and biota). The transport of the oil into the atmosphere in these previous investigations has been limited to only evaporation, a volatility dependent pathway.
View Article and Find Full Text PDFMethyl salicylate (MeSA) is a green leaf volatile (GLV) compound that is emitted in significant amounts by plants, especially when they are under stress conditions. GLVs can then undergo chemical reactions with atmospheric oxidants, yielding compounds that contribute to the formation of secondary organic aerosols (SOAs). We investigated the adsorption of MeSA on atmospheric air/water interfaces at 298 K using thermodynamic integration (TI), potential of mean force (PMF) calculations, and classical molecular dynamics (MD) simulations.
View Article and Find Full Text PDFGreen leaf volatiles (GLVs) are oxygenated hydrocarbons that are emitted by plants, especially under stress conditions such as mechanical damage and local weather changes. GLVs can react with photochemically-generated oxidants (e.g.
View Article and Find Full Text PDFPolycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants in the atmosphere, predominantly known for their toxicity. Although there has been substantial work on the atmospheric degradation of PAH, little is known about how the presence of atmospheric droplets (e.g.
View Article and Find Full Text PDFAtmospheric-pressure photoionization (APPI) mass spectrometry benefits from the addition of an ionization-enhancing dopant such as benzene. A passive dopant-delivery system has therefore been designed for use with the orthogonal APPI source within a commercial liquid chromatographic instrument with mass spectrometric detector. By providing the dopant in the gas phase, the newly designed equipment avoids mixing problems and other difficulties associated with liquid dopant addition.
View Article and Find Full Text PDFThe adsorption and photochemical reaction of naphthalene vapor at the air-water interface of water films (22 microm and 450 microm) were studied in a horizontal flow reactor. Experiments were conducted in the regime where gas-phase mass transfer resistance did not limit the uptake. The equilibrium uptake was dependent on water film thickness only below 1 microm.
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