Atmospheric sink of styrene, α-methylstyrene, trans-β-methylstyrene and indene: Rate constants and mechanisms of Cl atom-initiated degradation

Secondary organic aerosol formation from α-methylstyrene atmospheric degradation: Role of NO level, relative humidity and inorganic seed aerosol

“…In this sense, styrene and its derivatives, including αmethylstyrene are aromatic compounds present in polluted areas (Okada et al, 2012;Knighton et al, 2012;Gentner et al, 2013;Zhang et al, 2017), potentially leading to SOA and photochemical ozone formation (Diaz-de-Mera et al, 2017;Berezina et al, 2017;Tajuelo Programa), 2007). Once in the atmosphere, α-methylstyrene can be degraded by oxidation with the main tropospheric oxidants, although its dominant atmospheric loss process is clearly its reaction with OH radical (Tajuelo et al, 2019b). These reactions give rise to gas phase products (Bignozzi et al, 1981;Le Person et al, 2008;Tajuelo et al, 2019b), but SOA formation is also expected, since the aerosol formation from the styrene photolysis and oxidation with OH radicals and ozone has been reported previously (Diaz-de-Mera et al, 2017;Tajuelo et al, 2019a), and both compounds are structurally similar.…”

“…Once in the atmosphere, α-methylstyrene can be degraded by oxidation with the main tropospheric oxidants, although its dominant atmospheric loss process is clearly its reaction with OH radical (Tajuelo et al, 2019b). These reactions give rise to gas phase products (Bignozzi et al, 1981;Le Person et al, 2008;Tajuelo et al, 2019b), but SOA formation is also expected, since the aerosol formation from the styrene photolysis and oxidation with OH radicals and ozone has been reported previously (Diaz-de-Mera et al, 2017;Tajuelo et al, 2019a), and both compounds are structurally similar.…”

Secondary organic aerosol formation from styrene photolysis and photooxidation with hydroxyl radicals

“…After allowing approximately 30 min for mixing, the lamps were turned on to initiate styrene photolysis or photooxidation. OH concentrations were estimated from the measured styrene decay due to OH reaction (k OHþstyrene ¼ (5.87 ± 0.15) Â 10 À11 cm 3 molecule À1 s À1 ) (Atkinson and Aschmann, 1988) and photolysis ((5.92 ± 0.52) Â 10 À5 s À1 ) (Tajuelo et al, 2019), being approximately 2 Â 10 6 radicals cm À3 , so of the same order of magnitude as the 12 h daytime average OH concentration in the troposphere (Hein et al, 1997).…”

“…Styrene is highly reactive in the atmosphere due to its unsaturated characteristics. Thus, it is primarily eliminated by reaction with OH, NO 3 , O 3 and Cl and as well as by photolysis during daylight hours (Le Person et al, 2008;Tajuelo et al, 2019;Tuazon, 1993). The gas-phase reaction of styrene and OH has been investigated in previous studies, most of them focused on measuring the rate constant of the initial reaction and identifying the atom in the styrene double bond that is more reactive with OH radicals (Atkinson and Aschmann, 1988;Bignozzi et al, 1981;Tuazon et al, 1993).…”

Kinetic Measurements of Cl Atom Reactions with C5–C8 Unsaturated Alcohols

“…Heterogeneous reactions involving sea salt and ozone are also a source of Cl atoms in the marine boundary layer [31,32]. Over the last two decades, although several experimental and theoretical works debated the potential impact of Cl oxidation with numerous VOCs in the tropospheric chemistry [33][34][35][36][37], the reactivity of some unsaturated alcohols is still not well established.…”