中文摘要：

以羧甲基壳聚糖（CMC）和海藻酸钠（SA）为原料，京尼平（GP）为交联剂，制备具有pH敏感性的CMC/SA半互穿网络（semi-IPN）水凝胶.利用特性黏数、红外光谱对CMC/SA水凝胶的半互穿网络结构及形成机理进行了分析与表征；对水凝胶的力学性能进行了测试；探讨了pH值及交联剂含量对水凝胶溶胀性能的影响.结果表明，京尼平交联的CMC/SA水凝胶具有半互穿网络结构.当w（CMC）：w（SA）=5：5时，CMC/SA水凝胶的断裂强度达到最大值（59 MPa），分别比纯的CMC（40 MPa）和SA（36 MPa）提高了47.5%和63.9%；当SA含量为60%时，CMC/SA水凝胶的断裂伸长率达到最大值（13.0%）.当pH〈3.0时，溶胀率随pH值的增大而减小，pH=3.0时，溶胀率最小（186%）；当pH〉3.0时，溶胀率随pH值的增大而增大，pH=9.0时，溶胀率最大（886%）.京尼平交联的CMC/SA半互穿网络水凝胶具有明显的pH敏感性、溶胀可逆性及对pH的快速响应性.

英文摘要：

The carboxymethyl chitosan （CMC）/sodium alginate （SA） semi-interpenetrating polymeric network （semi-IPN） hydrogel was prepared by incorporating SA into cross-linked CMC using genipin （GP） as the cross-linker.The semi-IPN formation and cross-linking reaction mechanism of the genipin-cross-linked CMC/SA hydrogel were confirmed by means of the instrinsic viscosity measurement and Fourier transform infrared spectroscopy （FTIR）.According to the measurements of mechanical properties,when the weight ratio of CMC and SA was 5：5,the tensile strength of the CMC/SA hydrogel in dry state reached 59 MPa,which was about 47.5% and 63.9% higher than that of pure CMC （40 MPa） and SA （36 MPa）.The largest elongation at break of the CMC/SA hydrogel was 13.0% when SA content was 60%.The influences of the pH values and cross-linking agent concentration on the swelling characteristics of the semi-IPN hydrogel were investigated in detail.Experimental results show the swelling ratio of the semi-IPN hydrogel decreases with increasing pH values at pH 〈 3.0,whereas at pH 〉 3.0,the swelling ratio increases with increase of pH values.At pH=3.0,the swelling ratio is the lowest （186%）,while at pH=9.0,the swelling ratio is the highest （886%）.It exhibits significant pH-sensitivity.In addition,the semi-IPN hydrogel exhibits reversibility and rapid response in swelling to pH changes.This type of semi-IPN hydrogel may be useful for stimuli-responsive drug delivery or as alternative sorbents in the removal or separation of dyes.