Painstakingly woven from the cocoons of silkworms, silk has been valued for more than 4,000 years as a luxury material. More than just beautiful, silk is also lightweight, strong and biocompatible, allowing it to be used for clothing, medical materials and more. However, conventional silk has a glaring weakness—it shrinks and loses its shape after repeated exposure to moisture.
Researchers at Tohoku University have developed high-performance silk that largely solves this weakness. Instead of tampering with the silk fibers, the research team targeted an earlier step in the process by altering the diet of silkworms. The result is silk fibers with 50% greater tensile strength and reduced shrinkage after wetting and drying to less than one-quarter that of untreated silk. These improvements were seen even when the silk fibers were processed into yarn and woven fabrics, meaning that we may be on the right path to using this "super silk" effectively in final products. The findings are published in the Journal of Industrial Textiles.
These improvements were achieved by adding plant-derived cellulose nanofibers (CNFs) to silkworm feed. Other methods may require toxic chemical treatments or extensive changes to the silk production process. In contrast, simply adding a sprinkle of sturdy CNF to silkworm feed represents a practical and environmentally friendly way to produce higher-value silk products.
