尿素脱胶对丝素蛋白气凝胶力学性能的影响

为提高丝素蛋白气凝胶的力学性能,采用尿素溶液体系对蚕丝进行脱胶处理后,经丝素蛋白溶解、稀释、冷冻干燥制备得到丝素蛋白气凝胶,借助扫描电子显微镜、X射线衍射光谱仪、红外光谱仪和万能材料试验机对气凝胶的形貌与结构进行分析,并与碳酸钠脱胶蚕丝制备的气凝胶进行对比。结果表明:非碱体系的尿素脱胶可降低对丝素蛋白的损伤,制备得到的气凝胶形貌完整,具有稳定的骨架结构,β-折叠结构相对含量为50.27%,结晶度为49.33%;压缩形变为70%时,尿素脱胶气凝胶的压缩强度为(32.36 ± 2.35) kPa,压缩模量为(119.31 ± 8.93 ) kPa,上述指标均远高于碳酸钠脱胶工艺制备的丝素蛋白气凝胶。

Effect of urea degumming on mechanical properties of silk fibroin aerogels

Aiming at improving mechanical properties of silk fibroin aerogel, a urea degumming process applied on raw silk was reported, and the silk fibroin aerogel was prepared through fibroin dissolution, dilution and freeze-drying. Meanwhile, the morphology and structure of the aerogel were analyzed by scanning electron microscopy, X-ray diffraction spectroscopy, infrared spectrometer and universal material testing machine. The results of which were compared with the aerogel prepared from sodium carbonate degummed silk. The findings show that the non-alkali urea degumming process has a little damage on silk fibroin, and the prepared aerogel exhibits a complete morphology and a stable skeleton structure, with relative content of its β-sheet structure being 50.27% and its crystallinity 49.33%. The compressive strength and compressive modulus of the aerogel are found to be (32.36±2.35) and (119.31± 8.93) kPa at 70% the compression deformation respectively, which are much higher than those of fibroin aerogels prepared through sodium carbonate degumming process.