PVP/CHI交联共混水凝胶的pH敏感性研究

Study on pH sensitivity 0f PVP/CHI blend hydrogels

制备戊二醛交联的PVP/CH I共混水凝胶,红外光谱佐证了凝胶网络的生成。pH敏感性实验表明,凝胶的溶胀率在pH=1.0的介质中最大,在pH=4.0的介质中次之,在中性或pH=9.0的碱性介质中最低,表明凝胶具有明显的pH敏感性。CH I含量、交联剂用量、CH I脱乙酰度均对凝胶的pH敏感性有影响,CH I含量40%、交联剂用量0.3%、CH I脱乙酰度99%的PVP/CH I凝胶pH敏感性较显著。介质pH值由1.0到7.0变化时,凝胶拉伸强度随着溶胀率的降低而增大。

Polyvinylpyrrolidone（PVP）/Chitosan（CHI） blend hvdrogels were prepared with glutaraldehyde as crosslinking agent and hydragel networks are proved by FTIR spectra. It is suggested from the pH sensitivity experiments that swelling ratio of the hydrogel is greatly high in strong acid medium （pH = 1.0 ）, decreases in weak acid medium （pH = 4. 0） and is lowest in neutral（ pH ：7.0 ）or base medium（ pH = 9.0）. In the meanwhile, pH sensitivity of PVP/CHI blend hydrogel is innuenced by some preparation conditions and is more significant when CHI content is 40% ,erosslinking agent content is 0. 3% and deacrylafion degree of CHI is 99%. Tensile strength of the hydrogels increases with decreasing of sweUingratio when pH of the medium changes from 1.0 to 7.0.