Organic acid evaporation kinetics from aqueous aerosols: implications for aerosol buffering capacity in the atmosphere

Abstract

The acidity of atmospheric aerosols controls their impacts on heterogeneous and multiphase reactions, cloud formation, and human health. Recently, it has been shown that multiphase buffering can shift aerosol pH...

Direct quantification of changes in pH within single levitated microdroplets and the kinetics of nitrate and chloride depletion

“…Bulk-phase refractive index measurements were performed using an ABBE-3L refractometer (Bausch & Lomb) as previously described. 26 The refractive indices of glycine solutions are shown in ESI Figure S1.…”

Effect of an Electric Field on the Structure and Stability of Atmospheric Clusters

“…9 Lasers are also a source of large electric fields on the order of 0.1 V Å −1 , and these have recently been used to trap and levitate atmospheric aerosols. 10 Simulations of bulk systems in electric fields, especially aqueous systems, using empirical force field models, have been a popular topic for many years; for some reviews, see e.g., refs 11 and 12. Computational studies of how electric fields affect small clusters, however, are less common.…”

“…For example, in ESI-MS, the actual electric field is highly nonuniform and may exceed 0.1 V Å –1 at the tip of the Taylor cone. , Near gas–solid or gas–liquid interfaces, the presence of strong electric potential gradients also mean that large electric fields up to 0.1 V Å –1 may locally exist very close to the interface . Lasers are also a source of large electric fields on the order of 0.1 V Å –1 , and these have recently been used to trap and levitate atmospheric aerosols …”

Single Droplet Tweezer Revealing the Reaction Mechanism of Mn(II)-Catalyzed SO2 Oxidation

“…34,47,48 With the AOT, one can measure the droplet radius online with nanometer precision using the Whispering Gallery Mode (WGM) spectra, and with high time resolution (1 spectrum/second). 34,55,56 With such high sensitivity and time resolution, the reaction kinetics can be measured at low gas reactant concentration, such as parts per billion levels, comparable to the actual atmospheric conditions. Moreover, a single droplet can be steadily levitated for several hours to days, thereby providing sufficient time for continuous measurement of the reaction.…”

“…Moreover, a single droplet can be steadily levitated for several hours to days, thereby providing sufficient time for continuous measurement of the reaction. 34,55,56 Furthermore, the AOT can be coupled with a sample cell wherein the ambient conditions of the trapped droplet (e.g., gas reactant concentration, RH, and temperature) can be precisely controlled. Fine-tuning these conditions allows the investigation of the dependence of the reaction rate on aerosol properties, including pH and ionic strength (I).…”