An improved model for the penetration of charged and neutral aerosols in the 4 to 80 nm range through stainless steel and dielectric meshes

This study deals with nanoparticle charge effect combined with charge conduction capacity in relation to meshes. Penetration tests were conducted on charged and uncharged copper and carbon particles (4–80 nm range) and a neutral aerosol using both stainless steel and synthetic meshes.The results of charged, uncharged and globally neutral aerosol penetration reveals that the stainless steel mesh penetrations do indeed obey the Cheng and Yeh (1980) Brownian capture expression. Penetrations obtained for polymer fibre meshes deviate widely from this expression. Moreover, neutral aerosol penetration does not increase steadily as the particle diameter increases. Electrostatic force-based analysis of penetration mechanisms for charged and uncharged particles provides an explanation for these deviations and leads to a proposed fibre charge-based penetration model. This model considers the charge distribution in an aerosol at Boltzmann equilibrium and accurately describes the increase in dielectric media penetration by globally neutral aerosols, which behave differently to particles with no charge.

Graphical AbstractVariation in 150 μm fluortex mesh penetration for an aerosol at Boltzmann equilibrium with respect to linear charge density.Figure optionsDownload high-quality image (133 K)Download as PowerPoint slideHighlights
► A methodology is developed to determine indirectly the charge densities of screens.
► A new model considering both Coulomb force and Brownian diffusion is developed.
► The model explains penetration for dielectric screens with a neutral aerosol.