Method of measuring metallic cation and water transport numbers for cation exchange hydraulically impermeable membranes and test cell therefor

A method of measuring metallic cation and water transport numbers for cation exchange hydraulically impermeable membranes comprising:

• forming a cell, said cell comprising two half cells, each of said half cells containing an internal horizontally disposed, inwardly directed, truncated right conical inner chamber, said cell being formed by joining said half cells at their truncated apexes so that said truncated chambers are aligned and abut each other to form a biconic electrolytic cell, said half cells having one of said membranes sealingly suspended therebetween to form an anode and a cathode compartment, each of said compartments having electrode means, heating means, sensing means, stirring means and electrolyte introduction means;
• filling said anode and cathode compartments with anolyte and catholyte solutions and heating said solutions to equilibrate said membrane at a preselected test temperature;
• removing said solutions and replacing them with weighed portions of the same solutions;
• adding a measured amount of radioactive tracer material to said anolyte solution;
• heating and stirring said solutions to achieve a uniform concentration of said anolyte and tracer;
• energizing said electrode means to electrolyze said solutions for a period of time, said electrolysis producing a transfer of said tracer material through said membrane into said cathode compartment;
• at the conclusion of said electrolysis period, measuring the quantity of tracer which has passed through said membrane;
• and
• measuring the net change in the water content of the electrolyte in each compartment, said quantities being indicative of the moles of metallic cation and water which have been transferred.