Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Advanced Materials Laboratory, Department of Macromolecular Science, Fudan University, Shanghai 200433, China, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China, and Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
Biomacromolecules. 2010 Nov 8;11(11):2890-5. doi: 10.1021/bm100643q. Epub 2010 Sep 29.
Films of regenerated silk fibroin (RSF) are usually brittle and weak, which prevents its wide application as a structural material. To improve the mechanical properties of RSF film, uniaxial extension under swollen conditions was employed to introduce preferred orientation of molecular chains of silk fibroin. Such a prestretching treatment resulted in the strain at break, ultimate stress, Young's modulus, and energy to break along the predrawn direction of the RSF film increasing from approximate 5%, 90 MPa, 2.7 GPa, and 2.1 kJ/kg to 35%, 169 MPa, 3.5 GPa, and 38.9 kJ/kg, respectively, which is an attractive combination of strength and toughness. The mechanism of these property enhancements was investigated using techniques such as small-angle X-ray scattering, wide-angle X-ray diffraction, atomic force microscopy, and dynamic mechanical analysis.
再生丝素蛋白（RSF）薄膜通常很脆且强度低，这限制了其作为结构材料的广泛应用。为了改善 RSF 薄膜的力学性能，采用溶胀状态下的单轴拉伸来引入丝素蛋白分子链的择优取向。这种拉伸预处理使 RSF 薄膜在沿预先拉伸方向的断裂伸长率、极限应力、杨氏模量和断裂能分别从约 5%、90 MPa、2.7 GPa 和 2.1 kJ/kg 增加到 35%、169 MPa、3.5 GPa 和 38.9 kJ/kg，表现出了强度和韧性的理想结合。使用小角 X 射线散射、广角 X 射线衍射、原子力显微镜和动态力学分析等技术研究了这些性能提高的机制。
