[in Japanese]

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[in Japanese]

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[in Japanese]

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Reverse osmosis separation of several organic solutes from aqueous solutions-monocarboxylic acids, esters, aldehydes, ketones and alcohols were investigated using cellulose acetate butyrate membranes. Separation was not so good as reported by Manjikian and virtually same as with cellulose acetate membranes. Matsuura's correlation is applicable to cellulose acetate butyrate membrane separation except high Taft's number.

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The formation of interpolymer complex of cellulose acetate phthalate (CAP) with polyvinylpyrrolidone (PVP) was investigated by turbidity and IR measurements. The complex is formed through hydrogen bonding between carboxyl groups of CAP and carbonyl groups of PVP. Reverse osmosis properties of the interpolymer membrane (1: 1) prepared from CAP and PVP were investigated using aqueous solutions of organic and inorganic compounds. This membrane shows high water permeability, higher rejection for hydrophobic solute than hydrophilic one, but lower rejection for salts, compared with the CAP membrane.

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A new type of the charged membrane has been prepared from sulfonated polysulfone. The effects of casting solution composition, evaporation temperature and evaporation period on the performance of the resulting membranes have been studied. N-Methyl-2-pyrrolidone was used as a casting solvent. The optimum composition of a casting solution was found to be the ratio of sulfonated polysulfone: solvent: lithium nitrate as 1: 4: 0.2 (wt-%). The membrane formed by casting the solution and evaporation at 65°C for 60min. had water flux of 6.7l/m² hr and salt rejection of 93.9% at 80kg/cm ³ with 5000 ppm. Na Cl. It was found that salt rejection (R_S), water permeability (k) and water content (H) were expressed in the following equation, k=A·exp (-BR_S) k=A · exp (-B (1-H) /H). The membrane performance showed a typical charged membrane characteristic.

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