Enhancing the toughness of regenerated silk fibroin film through uniaxial extension.
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.
Yin
Jianwei
J
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.
Chen
Erqiang
E
Porter
David
D
Shao
Zhengzhong
Z
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D012831:Bombyx / Q000737:chemistry; D005349:Fibroins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D005349:Fibroins