Silkworm Silk Fibers with Multiple Reinforced Properties Obtained through Feeding Ag Nanowires

Silkworm silk fibers have been woven into textiles for thousands of years, because of their attractive luster, good mechanical properties, excellent biocompatibility, and large-scale production. With the development of human society, preparation of silk fibers with modified or enhanced properties are highly desirable for potential applications in structural materials and smart textiles. Herein, we realized the reinforcement of multiple properties of silk fibers by feeding silkworms with Ag nanowire (Ag NW) modified diets. The obtained silk fibers show obviously enhanced comprehensive mechanical properties, including improved tensile strength, elongation at break, tensile modulus, and toughness, which are increased by 37.2%, 37.6%, 68.3%, and 69.8%, respectively. Furthermore, compared with unmodified silk, the electrical conductivity and thermal conductivity of modified silk fibers are improved by 246.4% and 32.1%, respectively. The analysis on the components and structure shows that the incorporated Ag NWs lead to increased content of random coil/α-helix, improved orientation of crystallites, and increased content of Ag compared to pristine silk fibers, which may contribute to the enhanced mechanical, electrical, and thermal properties. Graphical Abstract