Gelation and swelling behavior of oxidized konjac glucomannan/chitosan hydrogel

The gelating and swelling mechanisms of the hydrogel formed from oxidized konjac glucomannan (OKGM) and chitosan (CS) were studied by Fourier transform infrared (FT-IR) spectrometry. FT-IR spectra illustrate that the interaction of polysaccharides forms the hydrogen bonds and interchain salt bonds and the dissocation of which dominates the swelling behavior in buffer solutions of different pH. The concentration of salt ion has effect on swelling behavior through the difference of salt ion concentration between in solution and in network of hydrogel, which causes penetrating pressure. Moreover, the Swelling degree and hydrogel strength could be modulated by varying conditions. It is indicated that the hydrogel has pH-sensitive and salt ion sensitive properties. The prepared optimum condition selected by varying conditions is thatr=0.2;t=30 min;T _p=343 K andI=1.6. Foundation item: Supported by the National Science Foundation of China (29574173) Biography: He Dong-bao (1945-), male, Professor, research direction: modifying and gelating of natural polysaccharides.