Role of humidity on the structures and properties of regenerated silk fibers

• Main Authors: Qingfa Peng, Huili Shao, Xuechao Hu, Yaopeng Zhang
• Format: Article
• Language: English
• Published: Elsevier 2015-10-01
• Series: Progress in Natural Science: Materials International
• Subjects: Dry spinning; Relative humidity; Biomimetic; Regenerated silk fibroin; Wide angle X-ray diffraction
• Online Access: http://www.sciencedirect.com/science/article/pii/S100200711500091X
• ISSN: 1002-0071

Silk fiber was processed from highly concentrated spinning dope to solid fibers along with water removal. To understand the mechanism of water removal during silk fiber spinning process, a microfluidic chip was designed and applied to investigate the structures and mechanical properties of two kinds of regenerated silk fibroin fibers dry-spun at different relative humidity. The experimental results showed that the diameters of the fibers spun at 40% RH are always larger than the fibers spun at 50% RH due to different removal rates of water. The fibers spun at low humidity contain more β-sheet structure and lower degree of chain orientation and crystalline orientation. These results indicate that the fast phase transition of silk fibroin from sol–gel to silk fiber undergoes with rapid water removal and higher fiber orientation relates to more residue water and drawing force.