Diameter Refinement of Electrospun Nanofibers: From Mechanism, Strategies to Applications

Electrospinning has drawn wide attention for its powerful capacity to produce ultrafine nanofibers (UNFs) from various materials. These UNFs demonstrated significantly enhanced performance, such as ultra-high surface area, more porosity and stronger mechanical properties. Here, we comprehensively review their basic principles, state-of-the-art methods and preponderant applications. We begin with a brief introduction to the refinement theory of polymer jets, followed by discussion of factors affecting fiber refinement. We then discuss the refining strategies from the aspects of solution properties, spinning parameters, auxiliary force and post-treatment. Afterward, we highlight the most relevant and recent applications associated with the remarkable features of UNFs, including filtration materials, supercapacitors, biomedical materials and other applications. At the end, we offer perspectives on the challenges, opportunities, and new directions for future development of electrospun UNFs.