Preparation and properties of chitosan-poly(N-isopropylacrylamide) semi-IPN hydrogels

Abstract

Chitosan (CS), CS-poly(N-isopropylacrylamide)(PNIPAM) and their dyed (pyrene) hydrogels were prepared using glutaraldehyde (Glu) as a crosslinker. The gelation rate, swelling behaviors in ethanol/water mixtures, electricity-induced contraction and thermoresponse of the gels were investigated using fluorescence probe technique. Results showed that CS/Glu, and PNIPAM-containing CS/Glu gels exhibited similar properties in all aspects examined, except that the transparence of the CS-PNIPAM/Glu gel is very dependent upon the temperature. The CS-PNIPAM/Glu gel is transparent below 30°C, whereas opaque above 32°C. It is expected that this observation may be useful for the design and preparation of new kinds of hydrogel devices. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 474–481, 2000