Permeation of water through cation exchange membranes.

Water permeabilities as well as other membrane parameters, such as exchange capacity, water content, and specific conductance, have been measured for two cation exchange membranes in the H form. The conductance of membrane with low water content was less than that of the membrane with high water content. These data have been discussed in the light of an existing theory and found inadequate to explain the results in a quantitative way. Water permeability of the membranes subject to mechanical pressure was found to be higher than their isotopic water permeability, according to expectation. These data have been examined from the standpoint of thermodynamic and kinetic theories of water flow in membranes and used to estimate the average size of membrane pores.