Kinetics of the gas‐phase reactions of hydroxyl radicals with C₁–C₆ aliphatic alcohols in the presence of ammonium sulfate aerosols

Abstract

The effects of ammonium sulfate aerosols on the kinetics of the hydroxyl radical reactions with C 1 -C 6 aliphatic alcohols have been investigated using the relative rate technique. P-xylene was used as a reference compound for the C 2 -C 6 aliphatic alcohols study, and ethanol was used as a reference compound for the methanol study. Two different aerosol concentrations that are typical of polluted urban conditions were tested. The total surface areas of aerosols were 1400 m 2 cm Ϫ3 (condition I) and 3400 m 2 cm Ϫ3 (condition II

Investigations on the gas-phase photolysis and OH radical kinetics of methyl-2-nitrophenols

“…In recent studies, the formation of substantial yields of secondary aerosol was observed during the photolysis of nitrophenols in the reaction chamber. 31 It has been reported by Oh and Andino (2000 [35][36][37] that the presence of (NH 4 ) 2 SO 4 and NH 4 NO 3 aerosols leads to an increase in the rate of reaction of organic compounds such as methanol, ethanol and n-propanol with OH radicals. However, in a subsequent study by Sorensen et al, 38 who investigated the relative reactivity of OH radicals with methanol, ethanol, phenol, ethene, acetylene and p-xylene, no discernible effects of NaCl, (NH 4 ) 2 SO 4 and NH 4 NO 3 aerosol on the rate of loss of the compounds could be established.…”

Heterogeneous chemistry involving methanol in tropospheric clouds

“…The most likely heterogeneous process to consider here is the reaction of adsorbed CH 3 OH with OH: This heterogeneous process may also help to explain why a rapid production of HCHO was simultaneously observed in the cloud (Table 1). Laboratory measurements indicate that CH 3 OH on dry ammonium sulfate surfaces (relative humidity (RH) ∼35%) can react with OH to yield formaldehyde [ Oh and Andino , 2000, 2001]. According to these measurements, the rate of gas phase methanol reaction with OH is enhanced by about 30% in the presence of dry ammonium sulfate surfaces at ∼35% RH.…”

Analysis of hydroxyl radical formation in a gas‐liquid electrical discharge plasma reactor utilizing liquid and gaseous radical scavengers

“…Chemical probes have been used to assess radical formation in plasmas, particularly in the liquid phase and to a lesser degree in the gas phase. For example, the amount of • OH (mostly in the liquid phases) has been estimated using various chemical scavengers such as phenol, p‐xylene, n‐hexane, dimethyl sulfoxide (DMSO), esters such as dioxane, halides such as iodide and bromide, terephthalic acid, aliphatic alcohols, tert‐butyl alcohol, and dyes . The combination of OES and • OH scavengers was particularly useful in demonstrating that the • OH scavenging ability of a probe is dependent on its octanol‐water partition coefficient and concentration in a liquid phase pulsed corona discharge where the discharge channel propagates through the liquid .…”