Studies on elastic hydrogel membrane. I. Effect of preparation conditions on the membrane performance

The properties and the permeation characteristics of poly(vinyl alcohol) hydrogel membranes were investigated. The membranes have excellent elasticity and showed reversible compaction by operating pressure. The membrane performance was also changed reversibly by pressure, and was held stable at ambient temperature for more than 12 months. The hydrogel membrane was stable against temperature up to 40°C, and was melted down at 70°C. Rejection increased with operating pressure. In the case of 1% (w/w) aqueous solution of poly(ethylene glycol) whose degree of polymerization is 400, the rejection increased from 30 to 85% by changing operating pressure from 5 kg/cm2 to 60 kg/cm2. These results suggested the possibility for the pressure controlled fractionation of molecular weight.