Structure–property relationships of silk is an intriguing topic for silk‐based biomaterials research since these features are related to biomimicking the processing in natural silk fiber formation which results in excellent mechanical properties. Strain‐stiffening is common for spider silks and nonmulberry silkworm silks. However, the structural origin of strain‐stiffening remains unclear. In this paper, the strain‐dependent structural change of Antheraea pernyi silkworm silk is studied by X‐ray fiber diffraction and Fourier transform infrared spectroscopy under stretching. Based on a combination of mechanical and structural analysis, the molecular origins of strain‐stiffening in A. pernyi silk were determined. The relatively high content of the β‐sheets within the amorphous domains in A. pernyi silk is responsible for strain‐stiffening, where “molecular spindles” enhance the extensibility and toughness of the fiber.

中文翻译：

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蚕丝应变依赖性结构变化的比较研究：应变增强结构起源的认识

蚕丝的结构－特性关系是基于蚕丝的生物材料研究的一个有趣的话题，因为这些特征与生物模仿天然蚕丝纤维形成过程中的生物模仿有关，从而具有出色的机械性能。蜘蛛丝和非桑蚕丝的拉伸强度很常见。但是，应变刚度的结构起源仍不清楚。本文通过拉伸下的X射线纤维衍射和傅里叶变换红外光谱研究了per蚕蚕丝的应变依赖性结构变化。基于机械和结构分析的结合，佩妮曲霉的应变加筋分子起源丝绸被确定。pernyi丝中无定形域内β-折叠层的含量相对较高，这是造成应变刚度的原因，其中“分子纺锤体”增强了纤维的可延展性和韧性。