HYDRODYNAMIC CHARACTERIZATION OF AN ULTRAFILTRATION MEMBRANE

The hydrodynamic permeabilities of asymetric ultrafiltration membranes for distilled water, pure organic solvents and their mixtures have been measured. Darcy's law was used to describe the convective transport of water and organic solvents through this microporous ultrafilter. The permeability coefficient defined by this law could be used to characterize the membrane behaviour towards one class of these solvents. The permselectivity and permeability of polyethyleneglycol 4000 in aqueous solutions have been studied. The measured parameters were: the concentration, the pressure, the velocity and the time. For each parameter, we determinated the flow and the real and observed rejection coefficient under continuous and discontinuous conditions. The study of the limiting flow of there aqueous solutions were used for the determination of gel contents, C(g). Finally the cut-off of this membrane was determined from the variation of the observed rejection coefficient versus molecular weights of PEG.