Cyclic or Permanent? Structure Control of the Contraction Behavior of Regenerated Bombyx mori Silk Nanofibers

• Published in: Macromolecules Vol. 44; no. 19; pp. 7713 - 7718
• Main Authors: Yoshioka, Taiyo, Kawahara, Yutaka, Schaper, Andreas K
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11-10-2011
• Subjects: Applied sciences; Exact sciences and technology; Fibers and threads; Forms of application and semi-finished materials; Polymer industry, paints, wood; Technology of polymers; Silk; Wetting; Physical dressing; Air drying; Supramolecular structure; Mechanical properties; Nanofiber; Experimental study; Contraction; Mechanism
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma2014172

The interest in the physics and chemistry of natural silk is due to the extraordinary mechanical, chemical, and biological properties and high functionality of this material. In particular, its unique mechanical behavior, which has never been realized in man-made fibers so far, makes the silk so attractive for materials scientists. We report here the occurrence of pure cyclic contraction in fibroin nanofibers electrospun from regenerated Bombyx mori silk. Evidence is presented of the essential role the oriented noncrystalline molecular chains and the water-soluble silk-I crystal modification play in this reversible mechanical process. We also show that regenerated silk may permanently supercontract if it contains a minimum amount of silk-II β-crystals.