Abstract
The effects of membrane preparation variables on the reverse osmosis properties of cellulose acetate membrane have been investigated by water vapor sorption. Dependence of isotherm on the annealing temperature was not observed in casting conditions of one minute solvent evaporation and of annealing temperature of 60-80°C. This may indicate that the primary membrane structure is formed in the evaporation step and the dense layer is thin. The membrane prepared from Eastman 398-3 was more porous than one prepared from Wako Pure Chemicals. Reverse osmosis properties of cellulose membrane was discussed, based on the selective water adsorption on cellulose in the amorphous region, and a crevasse-like structure model was proposed. By using this model, a good agreement was obtained between the experimental and the calculated data.
