Diffusive deposition of submicrometer aerosol particles onto dielectric walls with a nonuniform surface charge distribution

Abstract

The deposition of charged, submicrometer aerosol particles onto solid walls is studied for surfaces of dielectrics having a nonuniform surface charge distribution. After measurement of the charge distributions on plastic sample surfaces using an electrostatic surface voltage meter, the deposition of particles by Brownian and turbulent diffusion and coulombic forces is investigated experimentally. The result shows that the enhancement of deposition depends on both the average surface voltage and the magnitude of the voltage variation over the surface. Experiments and a model calculation performed with an “imitation dielectric” wall readily explain the dependence of deposition enhancement on voltage distribution on the wall. The evaluation of deposition by Brownian and turbulent diffusion of particles and electrical forces is found to require an analysis in which the distribution of surface voltage is taken into consideration.