INFLUENCE OF PROTEIN ADSORPTION ON FLOW RESISTANCE OF MICROFILTRATION MEMBRANE

It is well known that the flow resistace and sieving property of a membrane change when protein adsorption, which is a specific interaction between the protein and membrane, occurs within the pores. The influence of the protein adsorption on the membrane hydraulic permeability was examined using bovine serum albumin (BSA) as the model protein and a nitrocellulose microfiltration membrane. The Kozeny-Carman equation, which has been applied to the laminar flow in a granular bed, was employed for the description of the flow property of the tortuous pore membranes. The flow resistance of the membrane after BSA adsorption was well evaluated from the reduced porosity due to the protein adsorption in the pores. Also, the equivalent diameter of the pore space of both the clean and preadsorbed membranes was evaluated by introducing the expression for the hydraulic mean diameter. Furthermore, it was found that a more significant protein adsorption at around the isoelectric point brings about a larger increase of the flow resistance of the preadsorbed membrane.