Isolation of Silk Mesostructures for Electronic and Environmental Applications

A ubiquitous feature of natural silk fibers is the presence of well-organized mesostructures, including microfibrils, nanofibrils, and nanoparticles. These mesoscale building blocks are typically well organized into sophisticated arrangements and contribute robust mechanical performance and functions as part of natural silk fibers. However, it remains a major challenge to directly isolate these mesostructures for engineering applications. Here, an environmentally friendly and scalable "partial dissolution and physical dispersion" strategy is developed to exfoliate silk fibers into different mesostructures, including microfibrils, nanofibrils, nanorods, and nanoparticles. On the basis of the advantages of these mesosilks in tunable sizes, sharp size distributions, high modulus, excellent redispersibility, as well as versatile processability, the applications of these mesosilks in electronic and environmental fields are further explored, including water treatment, recycling organic solvent, paper sensors, and nanofertilizers. These explorations open a new avenue for silk fiber applications while also providing a pathway to help address critical issues in electronic and environmental fields.