SPECIFIC VOLUME PHASE-TRANSITION OF POLYMER GELS OF THE SAME COMPOSITION BUT DIFFERENT OVERALL CONCENTRATION - FOCUSING ON A PARTICULAR TRANSITION POINT

Three types of polymer gels of the same composition but different overall concentration were prepared as follows: 2-acryloyloxyethyl acid phosphate (AEAP) monopolymer gels, AEAP/acrylamide (Am) copolymer gels, and sodium acrylate (SAc)/Am/N,N'-methylenebisacrylamide (Bis) copolymer gels. When the gels were immersed in acetone-water mixtures, the gels all underwent discontinuous volume changes at a particular acetone composition. This specific transition behavior is considered consistent with the constant miscibility of each gel polymer with an appropriate acetone-water mixture, even when the gel concentration changes.