Deciphering the Secrets of Silks: From Understanding to Synthesis and Modification

Abstract

Animal silks are with fascinating properties that outperform most synthetic fibers available today, which render them the perfect biomimicking targets. However, a decent understanding on their formation mechanism, structure and properties relationship needs to be acquired before we can successfully biomimick the silks and exploit their applications.

In this thesis, the effect of the non-repetitive (NR) terminal domains on the protein stability, the fibril and silk fiber formation was firstly explored. We then employed combined techniques to probe the mechanical responses of the silk fibrils and obtained useful insights on their mechanical designs. Further, a simple method was utilized to engineer a large covalently bonded silk protein which gave rise to artificial fibers with tenacity higher than its native counterpart. Finally, the mechanical response of different silk systems to twisting was studied by a home-made setup, which opens new route to investigate further possible applications of silk.