自组装的壳聚糖/SiO_2杂化膜

The self-assembled chitosan/SiO_2 whisker hybrid membrane

以硅溶胶为晶种，使硅酸钠在壳聚糖膜中自组装形成SiO2微粒和晶须，并得到壳聚糖／SiO2杂化膜（以下简称杂化膜）。用电子扫描电镜观察了SiO2微粒和晶须的形貌，研究杂化膜在水中的溶胀率，杂化膜的拉伸强度、伸长率和弹性模量等力学性能，杂化膜的热稳定性能。结果表明：杂化膜内SiO2为长3．0～6．0μm，宽150nm的晶须，以及直径为3．0μm的微粒；当膜内SiO2质量分数为7．5％时，杂化膜的力学性能达到最佳，其拉伸强度、弹性模量和断裂伸长率分别为38．39MPa、2383．02MPa、19．82％；随着杂化膜内SiO2质量分数从2．5％增加到12．5％，其溶胀率从112．0%下降到83．7％；杂化膜在200-800nm波长范围的吸光度也逐渐降低；杂化膜的分解温度为314℃，高于单纯壳聚糖膜的分解温度290℃，表明SiO2晶须与壳聚糖杂化可提高壳聚糖膜的热稳定性。

The chitosan/SiO2 whiskers hybrid membranes were successfully prepared by using silicon sol as the crystal source, and silicate sodium self-assembled in the chitosan membrane to form the particle and whisker of SiO2. The morphologies of SiO2 in hybrid membrane were observed by scanning electron micrograph （SEM）. The mechanics properties, the swelling ratio, the ultraviolet-visible spectrometer absorbency and the thermal stability of membranes were investigated. The results revealed that the morphologies of SiO2 whiskers were 3. 0-6.0μm length, and 150 nm width, and the diameter of particles was about 3. 0 μm. When the mass percent of SiO2 was 7.5%, the tensile strength, the elasticity modulus, and the elongation at break of hybrid membrane were optimum, and their value were 38. 39 MPa, 2383.02 MPa, 19.82%, respectively. With the mass percent of SiO2 increased from 2.5% to 12.5%, the optical absorbency was decreased gradually in the range of wave length from 200 to 800 nm, and the swelling ratio was decreased from 112.0% to 83.5%. The decomposition temperature of membrane was 314℃, which was higher than chitosan membrane 290℃, this suggested the biocompatible hybrid membranes have the good temperature stable.