Advances of Silk Nanofibrils: Preparation, Properties, and Applications

Silk nanofibrils (SNFs), the meso/microscale units of silk fibroin, show great potential in developing biodegradable materials with high strength, multiscale, and high performance. Most of the SNFs have high crystallinity due to the enriched β-sheet crystalline domains, which brings high mechanical strength. The inherent amphiphilicity and large specific surface area of SNFs favor the reassembly of hierarchical nanostructures. Exogenous ingredients can be introduced to the SNF system to strengthen the structural design and expanded their applications. This review summarizes the progress of SNFs including the preparation methods, the intrinsic properties, and various applications. The applications of the SNF-based materials in biomedicine, water purification, and flexible devices are discussed in detail. The increasing studies suggest a promising future of the SNFs as novel functional materials.