The Fig nbsp schematic shows the driven forces

The particles with higher molecular weight are rejected by the microfiltration membrane, deposited as a cake layer (Layer III) over the membrane surface. Due to the lower concentration of HSs in the bulk solution, a concentration boundary layer develops between the bulk solution and the cake layer. This prompts MG-262 of HS particles from the cake layer toward the adjacent solution (Layer II) due to the concentration gradient. In the presence of external d.c.