New phases and volume transitions of gels

Annaka Masahiko, T. Tanaka

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The copolymer gel of acrylic acid (anionic constituent, AAc) and methacryl-amido-propyl-trimethyl-ammonium-chloride (cationic, MAPTAC) were prepared by free radical polymerization. A systematic change in the macroscopic phase behavior was observed when the chemical composition was varied gradually. The largest number of phases was seven for the 460/240 gel (which consists of 460mM AAc and 240mM MAPTAC) and decreased as the ratio deviated from 460/240. Kinetic processes of swelling and shrinking were monitored under various conditions. Characteristic relaxation times of the gels in response to temperature, pH, or solvent changes are minutes in continuous changes and several hours in large discontinuous changes. However, the onset of a discontinuous transition was readily noticed within several seconds as a quick change in gel diameter. Stability was confirmed on selected phases for more than a month. The finding of the new phases in gels demonstrates the possibility that synthetic polymers may have similar phases that were known only to biopolymers.

Original languageEnglish
Title of host publicationPolymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering
PublisherPubl by ACS
Number of pages2
ISBN (Print)0841222169
Publication statusPublished - Dec 1 1992
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Chemical Engineering (miscellaneous)
  • Polymers and Plastics


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