# Electric Charge Effect on the Water Mass Transfer across Mixed Aqueous–Organic Droplet Interfaces

## TL;DR

This study investigates how electric charge affects water mass transfer across droplet interfaces, finding that charge has little impact compared to composition and temperature.

## Contribution

The novel combination of aerosol charging and photothermal spectroscopy enables direct measurement of charge effects on mass accommodation.

## Key findings

- Electric charge does not significantly affect the mass accommodation coefficient of aerosol droplets.
- Droplet composition and temperature are the dominant factors influencing mass transfer.
- Theoretical energy estimates confirm the negligible role of electric charge under atmospheric conditions.

## Abstract

Understanding gas-particle mass transport is essential
for predicting
aerosol behavior in the atmosphere and in industrial processes. The
mass accommodation coefficient, αM, is a key parameter
describing this exchange. Defined as the probability of a gas-phase
molecule adhering to a particle upon collision, αM presents a highly surface-sensitive property. Aqueous atmospheric
aerosol droplets carry electric charges, which accumulate near the
surface; however, their influence on the gas-particle mass transport
remains elusive. To access the influence of charge on αM, we combined an aerosol charging method with photothermal
single-particle spectroscopy, enabling direct water mass exchange
measurements on the surface of single aerosol droplets. We investigated
charged and neutral aqueous glycerol and tetraethylene glycol droplets
across a wide range of concentrations and temperatures. The micrometre-sized
droplets carried approximately 103 elementary chargesexceeding
typical atmospheric aerosol charge levelsyet our results show
that αM is independent of the droplet charge and
instead is dominated by composition and temperature. Theoretical estimates
of the charge-dipole and dipole–dipole interaction energies
corroborate this finding, highlighting that under atmospherically
relevant conditions, electric charge plays a negligible role in the
mass accommodation process.