LAUSR

With typical nanofibrous structure, silks spun by silkworms and spiders are the representative fibrous proteins that embody excellent mechanical properties and biological functions. However, it is still a challenge to directly extract silk nanofibers (SNFs) from natural silk fibers, to retain their nanostructures and properties, by a human and environment friendly approach for practical applications. Here, an all-natural strategy for simple, green, and scalable extraction silkworm and spider nanofibers in natural deep eutectic solvents has been developed. The liquid exfoliated SNFs have adjustable diameters from 20 nm (at the single SNF scale) to 100 nm and could be dispersed in water and organic solvents, enabling them to produce useful macroscopic biomaterials. The free-standing SNF membranes made from silkworm silk nanofibers (SSNFs) exhibited cytocompatibility, flexibility, and excellent mechanical performance, providing the ability to fabricate sustainable materials for tissue engineering and green electronics. Moreover, the SSNF could be used as a green and efficient dispersant of multiwall carbon nanotubes (MWNTs), and the SSNF/MWNT nanocomposite membranes could be used in wearable devices to monitor human activities.