多孔丝素材料的结构与性能研究

Study on the Structure and Properties of Porous Silk Fibroin Materials

用CaCl2·CH3CH2OH·H2O三元溶剂溶解蚕丝丝素,通过对丝素溶液冷冻之后的状态,以及冷冻干燥后丝素结构和性质的测试和分析,指出来用冷冻干燥法制备再生蚕丝丝素多孔材料时,若冷冻温度低于-20℃,则丝素的结构以无定型为主,含少量的SilkⅡ;若冷冻温度高于-20℃,则又增加了较多的Silk Ⅰ。采用冷冻干燥法可以制得平均孔径为10～3mμm、孔密度为1～2000个/mm2、孔隙率为35％～70％的多孔丝素材料。通过调节冷冻温度和丝素溶液质量分数,达到控制多孔丝素材料的上述形态结构、聚集态结构和透湿性、压缩性、强度、伸长率等物理性能的目的是可能的。将快速冷冻的丝素水溶液真空干燥之前,进行反复解冻—冷冻,则所制得的多孔丝素材料的孔径增大、孔密度减小;同时其压缩率和透湿性有所提高,拉伸断裂强度和在热水中的溶失率下降。

From the state of frozen silk fibroin solution prepared by dissolving silk fibroin in ternary solvent CaCl2.CH3CH2OH.H2O and the test analysis of the structure and properties of frozen-dried silk fibroin, when porous regenerated silk fibroin materials are prepared by freeze-drying, the structure of silk fibroin is mainly amorphous with freezing temperature below - 20℃ and contains a little silk II ; quite a lot of silk I formed with freezing temperature above-20℃ . Porous silk fibroin materials, with average pore radius between 10 and 300μm, pore density between 1 and 2,000 per square millimeter and porosity between 35 and 70 percent, could be prepared by freeze-drying. It is possible to control the aforementioned morphological structure, structure of aggregating state and physical properties as moisture permeability, compressibility, strength, elongation etc by adjusting freezing temperature and the concentration of silk fibroin solution. Quick-frozen silk fibroin solution is repeated thaw-freezing before vacuum-drying, thus the pore radius of porous silk fibroin materials increased and pore density decreased; meanwhile their compression rate and moisture permeability increased somewhat and tensile strength at break and losing solution percentage decreased in hot water.