Fiber morphology of spider silk: The effects of tensile deformation
Fiber morphology of spider silk: The effects of tensile deformation
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DOI：
10.1021/ma961293c
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发表时间：
1997-05-19
期刊：
影响因子：
5.5
通讯作者：
Jelinski, LW
中科院分区：
文献类型：
--
作者：
Grubb, DT;Jelinski, LW
通过广角X射线衍射(WAXD)图谱的详细分析，研究了棒状尼菲罗拖丝的纤维形态。WAXD给出了晶格尺寸、取向分布？结晶分数，以及晶体大小的估计。结果表明，晶体非常细小，取向良好。晶体的平均(最小)尺寸为2×5×7 nm，晶体中分子链与光纤轴之间的夹角Phi的半高宽(FWHM)为15.7度，取向函数f=0.981。X-射线结晶度在10-15%之间，非晶态衍射谱在各向同性环和取向晕之间划分为60：40，半高宽30度。这意味着三分之一的材料处于取向非晶态，链取向为fwm 43度，f=0.87。当纤维伸长到10%时，晶体的取向增加，正如在恒定体积下的仿射变形所预测的那样。在变形过程中结晶度没有明显变化，而横向晶体尺寸明显减小。
The fiber morphology of the dragline silk of Nephila clavipes has been investigated by the detailed analysis of wide-angle X-ray diffraction (WAXD) patterns. WAXD gives the crystal lattice dimensions, the orientation distribution? the crystalline fraction, and an estimate of the crystal size. It is found that the crystals are very small and well oriented. The mean (minimum) crystal dimensions are 2 x 5 x 7 nm, and the angle, phi, between the molecular chains in the crystals and the fiber axis has a full width at half-maximum (fwhm) of 15.7 degrees and an orientation function f=0.981. The X-ray crystallinity is in the range 10-15%, and the amorphous diffraction is divided 60:40 between an isotropic ring and an oriented halo with fwhm 30 degrees. This means one-third of the material is in the oriented amorphous state, with a chain orientation of fwhm 43 degrees and f=0.87. When the fiber is extended up to 10%,, the orientation of the crystals increases as predicted for affine deformation at constant volume. There is no observable change in crystallinity and apparently a small reduction in the lateral crystal size on deformation.