Impedance of Polypropylene Membranes Hydrophelized with Ethyl Alcohol

Abstract Impedance of hydrophobic polypropylene membranes, hydrophilized with aqueous ethyl alcohol solutions (EtOH) of varying concentrations, has been measured. It has been found that both the resistance and the Warburg coefficient decrease drastically in the EtOH concentration range of 0–31% (wt). For higher EtOH concentrations they remain essentially constant. Reciprocal behavior has been observed for the capacitance of the membranes studied which first increases and then stabilizes at concentrations higher than 31% (wt). It has been proved that hydrophilized membranes PP characterize a greater ion penetration with nonhydrolized membranes. Therefore, they are more effective as for as filtration processes are concerned.