Boulet-Audet Maxime, Terry Ann E, Vollrath Fritz, Holland Chris
Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK; ISIS Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, UK.
Acta Biomater. 2014 Feb;10(2):776-84. doi: 10.1016/j.actbio.2013.10.032. Epub 2013 Nov 5.
The remarkable mechanical properties of silk fibres stem from a multi-scale hierarchical structure created when an aqueous protein "melt" is converted to an insoluble solid via flow. To directly relate a silk protein's structure and function in response to flow, we present the first application of a Rheo-IR platform, which couples cone and plate rheology with attenuated total reflectance infrared spectroscopy. This technique provides a new window into silk processing by linking shear thinning to an increase in molecular alignment, with shear thickening affecting changes in the silk protein's secondary structure. Additionally, compared to other static characterization methods for silk, Rheo-IR proved particularly useful at revealing the intrinsic difference between natural (native) and reconstituted silk feedstocks. Hence Rheo-IR offers important novel insights into natural silk processing. This has intrinsic academic merit, but it might also be useful when designing reconstituted silk analogues alongside other polymeric systems, whether natural or synthetic.
丝纤维卓越的机械性能源于一种多尺度层次结构，这种结构是在一种水性蛋白质“熔体”通过流动转化为不溶性固体时形成的。为了直接关联丝蛋白在流动作用下的结构与功能，我们展示了流变红外（Rheo-IR）平台的首次应用，该平台将锥板流变学与衰减全反射红外光谱相结合。这项技术通过将剪切变稀与分子排列增加联系起来，为丝绸加工提供了一个新窗口，而剪切增稠则影响丝蛋白二级结构的变化。此外，与其他用于丝绸的静态表征方法相比，流变红外在揭示天然（原生）丝原料和再生丝原料之间的内在差异方面被证明特别有用。因此，流变红外为天然丝绸加工提供了重要的新见解。这具有内在的学术价值，但在设计再生丝类似物以及其他天然或合成聚合物体系时可能也会有用。
