1977 Volume 34 Issue 11 Pages 801-806
Uniform membranes of various water contents were formed to obtain a basis for membrane design. Poly (methyl methacrylate) (I) and N-vinylpyrrolidone-methyl methacrylate copolymer (II) were used as examples of hydrophobic and hydrophilic membrane materials, respectively. Permeabilities were measured for water, NaCl and urea. Membrane of I showed much higher water permeability than II membrane at the same water content. But there was no significant difference between them in NaCl and urea permeabilities. The permeation through I membranes was elucidated using a capillary model, by taking account of tortuosity. The same model can also be applied to II membranes, assuming the existence of bound water on capillary walls.
