Physical Chemistry

A Kinetic Model for Predicting Trace Gas Uptake and Reaction



A model is developed to describe trace gas uptake and reaction with applications to aerosols and microdroplets. Gas uptake by the liquid is formulated as a coupled equilibria that links gas, surface and bulk regions of the droplet or solution. Previously, this framework was used in explicit stochastic reaction-diffusion simulations to predict the reactive uptake kinetics of ozone with droplets containing aqueous aconitic acid, maleic acid and sodium nitrite. Using prior data and simulation results, a new equation for the uptake coefficient is derived, which accounts for both surface and bulk reactions. Lambert W functions are used to obtain closed form solutions to the integrated rate laws for the multiphase kinetics; similar to previous expressions that describe Michaelis–Menten enzyme kinetics. Together these equations couple interface and bulk processes over a wide range of conditions and don’t require many of the limiting assumptions needed to apply resistor model formulations to explain trace gas uptake and reaction.


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Supplementary material

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Supplementary Information
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