Microstructures and mechanical properties of silks of silkworm and honeybee.
Microstructures and mechanical properties of silks of silkworm and honeybee.
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DOI：
10.1016/j.actbio.2009.12.030
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发表时间：
2010-06
影响因子：
9.7
通讯作者：
Kai Zhang;Fangwei Si;Huiling Duan;Jianxiang Wang
中科院分区：
文献类型：
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作者：
Kai Zhang;Fangwei Si;Huiling Duan;Jianxiang Wang
蚕丝作为重要的生物材料，在生物组织支架、生物相容性涂层、药物载体等方面有着广泛的应用。采用环境扫描电子显微镜（ESEM）、扫描探针显微镜（SPM）、拉伸试验和纳米压痕测试等方法，对这些天然蚕丝的微观结构和力学性能进行了研究。结果表明，蜜蜂丝呈单纤维状，横截面呈圆形，质地比桑蚕丝更细更光滑。蜜蜂丝的弹性模量为6.5GPa，断裂应变为3.8%，表现出明显的线性脆性弹性特征;蚕丝的弹性模量为8.9GPa，断裂应变为15.7%，表现出明显的非线性分级破坏特征。此外，纳米压痕测量表明，蜜蜂丝表现出比蚕丝少得多的各向异性。蜜蜂丝的纵向模量与横向模量之比为2.0，而蚕丝的纵向模量与横向模量之比为18.9。蜜蜂和蚕丝的不同结构和机械性能可能是其特定生物功能的结果。
Natural silks as important biomaterials have wide applications in scaffolds for tissues, biocompatible coatings and drug delivery, etc. In this paper, we report on the microstructures and mechanical properties of honeybee and silkworm silks. The microstructures and mechanical properties of these natural silks are measured by environment scanning electron microscopy (ESEM), scanning probe microscopy (SPM), tensile tests, and nanoindentation. It is found that the honeybee silk appears as a single fiber with a circular cross-section and has a much finer and smoother texture than the silkworm silk. The honeybee silk exhibits a distinct linear and brittle elastic feature with an elastic modulus of 6.5GPa and a breaking strain of 3.8%, whereas the silkworm silk possesses a nonlinear and hierarchical failure character with an initial elastic modulus of 8.9GPa and a breaking strain of 15.7%. Moreover, the nanoindentation measurements show that the honeybee silk exhibits much less anisotropy than the silkworm silk. The ratio of the longitudinal modulus to the transverse modulus of the honeybee silk is 2.0, whereas that of the silkworm silk is 18.9. The different structural and mechanical properties of the honeybee and silkworm silks are likely a result of their specific biological functions.