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Relationships between supercontraction and mechanical properties of spider silk

Nature Materials volume 4, pages 901–905 (2005)Cite this article

Abstract

Typical spider dragline silk tends to outperform other natural fibres and most man-made filaments1. However, even small changes in spinning conditions can have large effects on the mechanical properties of a silk fibre2,3,4,5,6 as well as on its water uptake. Absorbed water leads to significant shrinkage in an unrestrained dragline fibre7,8 and reversibly converts the material into a rubber9. This process is known as supercontraction10 and may be a functional adaptation for the silk’s role in the spider’s web11. Supercontraction is thought to be controlled by specific motifs in the silk proteins12,13 and to be induced by the entropy-driven recoiling of molecular chains9,14. In analogy, in man-made fibres thermal shrinkage induces changes in mechanical properties15,16,17 attributable to the entropy-driven disorientation of ‘unfrozen’ molecular chains (as in polyethylene terephthalate)15,18 or the ‘broken’ intermolecular hydrogen bonds (as in nylons)17. Here we show for Nephila major-ampullate silk how in a biological fibre the spinning conditions affect the interplay between shrinkage and mechanical characteristics. This interaction reveals design principles linking the exceptional properties of silk to its molecular orientation.

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Figure 1: Comparisons of stress–strain curves of spider silks spun under different conditions.
Figure 2: General correlations between mechanical properties and the Csh of spider silk.
Figure 3: General correlations between mechanical properties and the breaking strain of spider silk.
Figure 4: The two states S1 and S2 and the stress–strain curves of their representative spider silks.

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References

  1. Vollrath, F. & Knight, D. P. Liquid crystalline spinning of spider silk. Nature 410, 541–548 (2001).

    Article  Google Scholar 

  2. Madsen, B., Shao, Z. & Vollrath, F. Variability in the mechanical properties of spider silks on three levels: interspecific, intraspecific and intraindividual. Int. J. Biol. Macromol. 24, 301–306 (1999).

    Article  Google Scholar 

  3. Knight, D. P. & Vollrath, F. Liquid crystals and flow elongation in a spider’s silk production line. Proc. R. Soc. Lond. B 266, 519–523 (1999).

    Article  Google Scholar 

  4. Knight, D. P., Knight, M. M. & Vollrath, F. Beta transition and stress-induced phase separation in the spinning of spider dragline silk. Int. J. Biol. Macromol. 27, 205–210 (2000).

    Article  Google Scholar 

  5. Vollrath, F., Madsen, B. & Shao, Z. The effect of spinning conditions on the mechanics of a spider’s dragline silk. Proc. R. Soc. Lond. B 268, 2339–2346 (2001).

    Article  Google Scholar 

  6. Liu, Y., Shao, Z. & Vollrath, F. Extended wet-spinning can modify spider silk properties. Chem. Commun. 19, 2489–2491 (2005).

    Article  Google Scholar 

  7. Shao, Z. & Vollrath, F. The effect of solvents on the contraction and mechanical properties of spider silk. Polymer 40, 1799–1806 (1999).

    Article  Google Scholar 

  8. Perez-Rigueiro, J., Elices, M. & Guinea, G. V. Controlled supercontraction tailors the tensile behaviour of spider silk. Polymer 44, 3733–3736 (2003).

    Article  Google Scholar 

  9. Gosline, J. M., Denny, M. W. & Demont, M. E. Spider silk as rubber. Nature 309, 551–552 (1984).

    Article  Google Scholar 

  10. Work, R. W. Dimensions, birefringences, and force-elongation behaviour of major and minor ampullate silk fibres from orb-web-spinning spiders-the effect of wetting on these properties. Text. Res. J. 47, 650–662 (1977).

    Article  Google Scholar 

  11. Lewis, R. V. Spider silk: The unravelling of a mystery. Acc. Chem. Res. 25, 392–398 (1992).

    Article  Google Scholar 

  12. Jelinski, L. W. et al. Orientation, structure, wet-spinning, and molecular basis for supercontraction of spider dragline silk. Int. J. Biol. Macromol. 24, 197–201 (1999).

    Article  Google Scholar 

  13. Yang, Z. et al. Supercontraction and backbone dynamics in spider silk: C-13 and H-2 NMR studies. J. Am. Chem. Soc. 122, 9019–9025 (2000).

    Article  Google Scholar 

  14. Shao, Z., Vollrath, F., Sirichaisit, J. & Young, R. J. Analysis of spider silk in native and supercontracted states using Raman spectroscopy. Polymer 40, 2493–2500 (1999).

    Article  Google Scholar 

  15. Wilson, M. P. W. Shrinkage and chain folding in drawn poly(ethylene terephthalate) fibers. Polymer 15, 277–282 (1974).

    Article  Google Scholar 

  16. Wu, G., Jiang, J. D., Tucker, P. A. & Cuculo, J. A. Oriented noncrystalline structure in PET fibers prepared with threadline modification process. J. Polym. Sci. B 34, 2035–2047 (1996).

    Article  Google Scholar 

  17. Simal, A. L. & Martin, A. R. Structure of heat-treated Nylon 6 and 6.6 fibres. I. The shrinkage mechanism. J. Appl. Polym. Sci. 68, 441–452 (1998).

    Article  Google Scholar 

  18. Keum, J. K. & Song, H. H. Thermal deformations of oriented noncrystalline poly (ethylene terephthalate) fibres in the presence of mesophase structure. Polymer 46, 939–945 (2005).

    Article  Google Scholar 

  19. Riekel, C., Madsen, B., Knight, D. & Vollrath, F. X-ray diffraction on spider silk during controlled extrusion under a synchrotron radiation X-ray beam. Biomacromolecules 1, 622–626 (2000).

    Article  Google Scholar 

  20. Eles, P. T. & Michal, C. A. A DECODER NMR study of backbone orientation in Nephila clavipes dragline silk under varying strain and draw rate. Biomacromolecules 5, 661–665 (2004).

    Article  Google Scholar 

  21. Grubb, D. T. & Ji, G. D. Molecular chain orientation in supercontracted and re-extended spider silk. Int. J. Biol. Macromol. 24, 203–210 (1999).

    Article  Google Scholar 

  22. Simmons, A. H., Michal, C. A. & Jelinski, L. W. Molecular orientation and two-component nature of the crystalline fraction of spider dragline silk. Science 271, 84–87 (1996).

    Article  Google Scholar 

  23. Beek, J. D. V., Hess, S., Vollrath, F. & Meier, B. H. The molecular structure of spider dragline silk: Folding and orientation of the protein backbone. Proc. Natl Acad. Sci. USA 99, 10266–10271 (2002).

    Article  Google Scholar 

  24. Eles, P. T. & Michal, C. A. Strain dependent local phase transitions observed during controlled supercontraction reveal mechanisms in spider silk. Macromolecules 37, 1342–1345 (2004).

    Article  Google Scholar 

  25. Fornes, R. E., Work, R. W. & Morosoff, N. Molecular-orientation of spider silks in the natural and supercontracted states. J. Polym. Sci. B 21, 1163–1172 (1983).

    Google Scholar 

  26. Grubb, D. T. & Jelinski, L. W. Fiber morphology of spider silk: the effects of tensile deformation. Macromolecules 30, 2860–2867 (1997).

    Article  Google Scholar 

  27. Garrido, M. A., Elices, M., Viney, C. & Perez-Rigueiro, J. The variability and interdependence of spider drag line tensile properties. Polymer 43, 4495–4502 (2002).

    Article  Google Scholar 

  28. Guinea, G. V., Elices, M., Real, J. I., Gutierrez, S. & Perez-Rigueiro, J. Reproducibility of the tensile properties of spider (Argiope trifasciata) silk obtained by forced silking. J. Exp. Zool. A 303, 37–44 (2005).

    Article  Google Scholar 

  29. Termonia, Y. Molecular modelling of spider silk elasticity. Macromolecules 27, 7378–7381 (1994).

    Article  Google Scholar 

  30. Shao, Z., Young, R. J. & Vollrath, F. The effect of solvents on spider silk studied by mechanical testing and single-fibre Raman spectroscopy. Int. J. Biol. Macromol. 24, 295–300 (1999).

    Article  Google Scholar 

  31. Thiel, B. L. & Viney, C. A nonperiodic lattice model for crystals in Nephila clavipes major ampullate silk. Mater. Res. Soc. Bull. 20, 52–56 (1995).

    Article  Google Scholar 

  32. Tsukada, M., Kato, H., Freddi, G., Kasai, N. & Ishikawa, H. Structural changes and dyeability of silk fibroin fibre following shrinkage in neutral salt solution. J. Appl. Polym. Sci. 51, 619–624 (1994).

    Article  Google Scholar 

  33. Vollrath, F. Strength and structure of spiders’ silks. Rev. Mol. Biotechnol. 74, 67–83 (2000).

    Article  Google Scholar 

  34. Oswald, H. J., Turi, E. A., Harget, P. J. & Khanna, Y. P. Development of a middle endotherm in DSC thermograms of thermally treated drawn pet yarns and its structural and mechanistic interpretation. J. Macromol. Sci.-Phys. B 13, 231–254 (1977).

    Article  Google Scholar 

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Acknowledgements

For funding we thank the British EPSRC (grant GR/NO1538/01) as well as the European Commission (grant G5RD-CT-2002-00738), the National Natural Science Foundation of China (NSFC 20434010), the Science and Technology Development Foundation of Shanghai (grant 05JC14009) and the AFSOR of the United States of America (grant F49620-03-1-0111). We thank C. Holland and D. Porter for constructive criticism.

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Authors and Affiliations

  1. Department of Macromolecular Science and The Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Fudan University, Shanghai, 200433, P.R. China

    Yi Liu & Zhengzhong Shao

  2. Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK

    Yi Liu & Fritz Vollrath

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Correspondence to Yi Liu, Zhengzhong Shao or Fritz Vollrath.

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Liu, Y., Shao, Z. & Vollrath, F. Relationships between supercontraction and mechanical properties of spider silk. Nature Mater 4, 901–905 (2005). https://doi.org/10.1038/nmat1534

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