1977 Volume 34 Issue 11 Pages 779-783
Permeation of water and water vapor through poly (L-leucine) (I) membrane was studied. Though the degree of hydration of I was about 1/3 of that of cellulose acetate (II) membrane, the water permeability of I was almost one order higher than that of II membrane. In comparison with poly (γ-methyl L-glutamate) (III) membrane, the degree of hydration was 1/2, and water permeability was almost the same. The activation energies determined from Arrhenius plots of hydraulic permeability and diffusion coefficient of water vapor are 2-2.5 times as high as that of viscous flow of water. The behavior was analysed by the free volume theory for mass transport, which showed that water was transported by diffusion of cluster of several water molecules through the loosely packed region between helices. Separation of water-soluble solutes through the homogeneous I membrane was examined. The rejection increased with the increase of molecular size of solute, and Bovine serum albumin was rejected in all the membranes. The solute rejection of I membrane was higher than that of III membrane, and this was considered to be due to hydrophobic nature of the side chain of I membrane.
