Ion Exchange Membranes Saturated with Hydrophobic Solvents

Filters made of cellulose acetate and nitrate were saturated with toluene or bromobenzene and interposed between aqueous solutions. The membranes thus formed behaved like cation exchange membranes with the same capacity for both solvents. K ‐ Na bi‐ionic potential, its dependence on temperature, K ‐ Na selectivity and mobility ratio were similar in membranes saturated with the above solvents. However the absolute magnitude of the diffusibility was some 30 times lower in toluene saturated membranes. Activation energy of membrane conductance was higher by about 3800 cal/mole in the toluene saturated membrane. Electroosmotic phenomena in the membranes were negligible or nil. It is suggested that these membranes represent a prototype of ion exchange membranes, where the fixed charges with their counterions and hydration shell are embedded in hydrophobic medium.