ELECTRICAL INTERACTIONS INVOLVED IN AEROSOL FILTRATION BY A DIELECTRIC POROUS MEMBRANE - THE CASE OF NUCLEPORE FILTER

Filtration by a dielectric medium has associated important electrostat ic effects, since during the operations (the filtration process, manip ulations, etc.) this medium accumulates considerable amounts of charge . In a filter-like Nuclepore, the charge is concentrated mainly at the rims of the pores. The electric field and its derivatives are analyti cally obtained and numerically evaluated for such a configuration of c harge, to determine Coulomb and dipolar forces acting on a particle, s upposed to be charged and polarizable. The important finding here is: in the vicinity of the pore rim the dipolar force is very high, exceed ing the Coulomb force. This points to the importance of including pola rization for a model of particle collection for that kind of filters. It could explain in part the observed accumulation of particles deposi ted in the pore vicinity in normal filtration situations. Copyright (C ) 1996 Elsevier Science Ltd.