Preparation and Characterization of Thermo-Sensitive Hydroxypropyl-Methyl Cellulose/Poly (N-isopropylacrylamide) Hydrogel

The best is to read these instructions and follow the outline of this text. Thermo-sensitive hydrogels based on linear HPMC and cross-linked PNIPAAm were prepared by the semi-IPN technique. The interior morphology of hydrogels was investigated by fluorescent microscope. The hydrogels were characterized by Fourier transform infrared (FTIR). The thermo-sensitivity, equilibrium swelling rate and swelling dynamics of these hydrogels were investigated. The chemical compositions and structures of the semi-hydrogels were similar to each other, as measured by FTIR. The results indicated that the swelling ratio of the hydrogel decreased with increasing temperature. In pH 7.4 buffer solution (37 degrees C), when the weight ratio of HPMC to NIPAAm was 1/100, the swelling ratio was the maximum. In comparision with a conventional PNIPA hydrogel, the semi-IPN hydrogel synthesized with hydroxypropyl-methyl cellulose exhibits a much faster response rate to temperature changes. For example, PNI-H05 loses 87% water within 5min, whereas the conventional hydrogel loses only about 25% water within 5 min. and about 50% water within 50 min.