Conductance Measurements in an Electrolytic Membrane Cell at Elevated Temperatures and Pressures

A Teflon test cell has been built to measure d-c membrane conductance in highly concentrated alkali metal hydroxide solutions at temperatures and pressures up to 200 ~ and 100 bar. The method allows these measurements to be conducted for membrane current densities up to 1.5 A-cm-~. The membrane voltage drop is determined using reference lectrodes which are placed on either side of the membrane. Conductance data were obtained for Nation | perfluorinated sulfonate ionomer of 1150 equiv, wt in the temperature ange of 100~176 Results show a tenfold decrease in specific conductance when the solution concentration is increased from 5.0 to 10.0M sodium hydroxide solution. Polymer ion exchange membranes must possess a combination of properties to enable their application in modern electrolytic industrial processes. These in-clude good permselectivity, low electrical resistance, chemical and thermal stability, as well as sufficient mechanical strength at the operating conditions. Ion-exchange membranes have already found application in electrochemical cells (1), in solid polymer electro