Protein adsorption properties on a microfiltration membrane: A comparison between static and dynamic adsorption methods

The effects of volumetric flow on the adsorption properties of bovine serum albumin (BSA) on the pore surface of sirasu porous glass (SPG) membrane having a pore size of 100 nm were studied by comparing the static adsorption method with the dynamic adsorption method, i.e. membrane filtration. The adsorption isotherm for the static adsorption was a Langmuir type while that for the dynamic adsorption was a multilayer type. The dynamic adsorption behavior was observed with the membrane pre-adsorbed by the static adsorption and it was shown that the flow in pore would cause the multilayer adsorption. The effects of the pre-adsorption on the dynamic adsorption behavior could be explained in terms of the surface coverage of pore surface by BSA and the electrostatic interaction between BSA and pore surface, which can be estimated by the zeta potential measurement. The change ratio of the zeta potential, |ζstat − ζ0|/|ζdyn − ζ0|, after the static adsorption was directly proportional to the surface coverage of BSA.