Characterisation of polymeric UF membranes by liquid–liquid displacement porosimetry

wo series of commercial polymeric (regenerated cellulose and polyethersulfone) membranes made by Millipore® have been characterized, obtaining their pore size distribution by liquid–liquid displacement porosimetry (LLDP). A fully automated porosimeter designed by us has been used in the determination of pore size distributions. Results show a good accuracy and reproducibility of LLDP measurements. Binary and ternary liquid mixtures have been used to wet and penetrate into the membrane pores when performing LLDP leading to quite similar results when an effective surface tension is assigned for the ternary mixture. The use of different liquid mixtures and soaking conditions allowed to assure a proper wetting of the membrane pores without damaging the membrane structure during the analysis.