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A series of N-isopropylacrylamide/trimethyl acrylamidopropyle
ammonium iodide(NIPAAm/TMAAI),N-isopropylacrylamide/trimethyl
methacryloyloxyethyl ammonium iodide(NIPAAm/TMMAI),and N-
isopropylacrylamide/3-methyl-1-vinyl--imidazolium iodide(NIPAAm/
MVI) copolymeric gels areprepared from the various molar ratios
of NIPAAm, cationic monomer TMAAI,TMMAI,and MVI, and N,N''-
methylene bisacrylamide(NMBA)in this article. The influences of
the amount of the cationic monomers in the copolymeric gels on
the swelling behaviors in water,various saline solutions,and
various temperatures areinvestigated. Results show that tha
swelling ratios of copolymeric gels are significantly larger
than pure NIPAAm gel,and the more the monomer content,the
higherthe gel transition temperature. In the saline solution,
results show that the swelling ratio of pure NIPAAm gel has not
significantly changed withan increase of the salt concentration
until the salt concentration is larger than 0.1M. The swelling
ratios for the copolymeric gels are decreasedwith increasing of
the salt concentration. In various saline solution,results show
that the anionic effects are greater than cationic effectsin the
presence of common anion,different cations and common cation,
different anions for these hydrogels. Finally, we also test the
reversibility of the NIPAAm/TMMAI copolymericgels. The
deswelling and reswelling kinetics are depended on the
temperature which is below or above the gel transition
temperature. The gel with little TMMAI content has a good
reversibity.
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