SPIDER SILK AND SILKWORM SILK FILAMENTS: FROM STRUCTURE TO PERFORMANCE

Abstract

In this thesis, we have built a general relation between the mechanical properties and the crystalline structure for silkworm silks and spider draglines. The knowledge not only explains why spider dragline is stronger than silkworm silk, but also sheds light on identifying robust techniques in fabricating ultra-strong silk/silk-like fibers.

In addition, the predicted strength by Network¿Non-slipping Fibril Bundle (N¿NFB) model, Bulk Network (BN) model and Network¿Slippery Fibril Bundle (N¿SFB) model was compared with measured strength for silks to explore the breaking mechanism across multi-levels.

Finally, the strain recovery (SR), as an important representation of the elasticity of materials, has been correlated to the structure for stretched silk fibers. The understanding not only explains why spider silk has a better strain recovery than silkworm silk but also illustrates the difference of strain recovery among silkworm silk fibers reeled at different speeds.