Effects of degumming conditions on the structure of the regenerated silk fibroin and the properties of its film

TL;DR

This study introduces a modified degumming process for silk fibroin that preserves its structure better than traditional methods, resulting in stronger, more crystalline silk films with improved properties.

Contribution

A novel degumming method that enhances the structural integrity and mechanical properties of silk fibroin compared to traditional approaches.

Findings

Higher ta-sheet content and crystallinity in fibroin with the new method.

Silk films exhibit increased tensile strength using the modified process.

Full sericin removal achieved with improved fibroin quality.

Abstract

The traditional degumming method using sodium carbonate solution severely damages the structure of silk fibroin and results in low molecular weight, which limits the properties and applications of silk materials. In this study, we report a modified degumming method and compared it with the traditional one. The results indicate that compared with the traditional degumming method, the modified degumming method produces silk fibroin with higher \b{eta}-sheet content (53.43% vs 46.68%), higher crystallinity (44.92% vs 42.72%), and more concentrated molecular weight (100 ~ 300 kDa vs 72 ~ 300 kDa), while allowing for the same full removal of sericin. Correspondingly, the film of the silk fibroin prepared with the modified degumming method exhibits higher \b{eta}-sheet content (35.22% vs 32.82%), higher crystallinity (26.96% vs 25.53%), and higher tensile strength (87.91 MPa vs 72.62 MPa). This work provides a degumming method superior to the traditional one and lays a foundation for the development of high-performance silk materials.