Electrophoresis, Vol.41, No.7-8, 578-587, 2020
Mass transfer of a neutral solute in polyelectrolyte grafted soft nanochannel with porous wall
A soft nanochannel involves a soft interface that contains a polyelectrolyte layer (PEL) sandwiched between a rigid surface and a bulk electrolyte solution. Mass transfer of a neutral solute in a combined electroosmotic and pressure driven flow through a polyelectrolyte grafted charged nanochannel with porous wall is presented in this work. Assuming the PEL as fixed charged layer and PEL-electrolyte interface as a semi-penetrable membrane, analytical solutions were obtained for potential distributions (for small wall potential). Velocity profiles were also derived in the same domains, for both inside and outside the PEL. Convective-diffusive species balance equation was semi-analytically solved inside the PEL. Expression of length averaged Sherwood number was also obtained and effects of different parameters, namely, drag parameter (alpha), Debye parameter (kappa over bar ), and PEL thickness were studied in detail. The variation of permeate concentration and permeation flux across the porous wall was obtained.