Pore size distributions based on AFM imaging and retention of multidisperse polymer solutes - Characterisation of polyethersulfone UF membranes with dopes containing different PVP

Several polyethersulfone ultrafiltration membranes have been made with smal l quantities of polyvinyl-pyrrolidone of different molecular weights. Our a im was to increase the permeability without significant changes in selectiv ity. Different approaches to get effective pore size distributions have been com pared between them and with the topographic results obtained from atomic fo rce microscopy (AFM) image analysis. In particular, the use of cumulative r etention coefficients: have proved to be preferable to adequately obtain ef fective pore size distributions: based on retention of multidisperse soluti ons. Within this frame, it has been proved that small PVP content of the studied membranes leads to different increasing permeabilities with very similar s electivities. (C) 2001 Elsevier Science B.V. All rights reserved.