Thermo‐sensitive swelling behavior in crosslinked N‐isopropylacrylamide networks: Cationic, anionic, and ampholytic hydrogels
- 5 September 1993
- journal article
- research article
- Published by Wiley in Journal of Applied Polymer Science
- Vol. 49 (9), 1553-1563
- https://doi.org/10.1002/app.1993.070490906
Abstract
Crosslinked polymer networks of N-isopropylacrylamide (NiPAAm) containing small amounts of either anionic or cationic comonomers, or mixtures of both were fabricated and characterized in terms of their aqueous swelling and critical behavior. These gels demonstrate critical transition temperatures in aqueous media between a highly solvated, swollen gel state and a collapsed, dehydrated network over temperature ranges comparable to that of pure NiPAAm, with modifications of gel critical points and respective temperature ranges dependent upon comonomer type and content. Copolymer gel swelling ratios are significantly larger than those reported for pure homopolymer NiPAAm gels, even when only 0.5 mol % of comonomer is incorporated. At temperatures exceeding the collapse transition point, all copolymer gels collapse to a state of nearly complete dehydration, demonstrating short-time collapsed-state swelling ratios far lower than those of pure NiPAAm networks. Collapse kinetics for the ionomeric gels are much more rapid than those of pure NiPAAm, achieving collapse state equilibrium on time scales of seconds. Swelling behavior as a function of pH, buffer type, ionic strength, crosslinking, and temperature is detailed over a range of copolymer compositions. © 1993 John Wiley & Sons, Inc.Keywords
This publication has 27 references indexed in Scilit:
- Swelling equilibria for acrylamide-based polyampholyte hydrogelsMacromolecules, 1992
- Surface-modulated skin layers of thermal responsive hydrogels as on-off switches: I. Drug releaseJournal of Biomaterials Science, Polymer Edition, 1992
- Structural investigations of dihexadecyl phosphate small unilamellar vesiclesLangmuir, 1991
- NMR study of poly(N-isopropylacrylamide) gels near phase transitionMacromolecules, 1991
- Swelling equilibria for weakly ionizable, temperature-sensitive hydrogelsMacromolecules, 1991
- Swelling equilibria for ionized temperature-sensitive gels in water and in aqueous salt solutionsThe Journal of Chemical Physics, 1990
- Thermally Reversible HydrogelsSwelling Characteristics and Activities of Copoly(N-isopropylacrylamide-acrylamide) Gels Containing Immobilized AsparaginasePublished by American Chemical Society (ACS) ,1987
- N-Isopropylacrylamide and N-Acryloxysuccinimide CopolymerPublished by American Chemical Society (ACS) ,1987
- Hydrophobic bonding in vinyl polymersJournal of Polymer Science Part B: Polymer Letters, 1965
- Investigations on Proteins and Polymers. IV.1 Critical Phenomena in Polyvinyl Alcohol-Acetate Copolymer SolutionsJournal of the American Chemical Society, 1951