Electrospun Fibrous Sponges: Principle, Fabrication, and Applications

Electrospun nanofiber materials, with the advantages of large specific surface area, small pore size, high porosity, good channel connectivity, and ease of functional modification, have been widely used in various fields including environmental governance, safety protection, and tissue engineering. With the development of functional fiber materials, the construction of three-dimensional (3D) fiber materials with stable structures has become a critical challenge to expanding application and improving the performance of electrospun fibers. In recent years, researchers have carried out a lot of studies on the 3D reconstruction of electrospun fiber membranes and direct electrospinning of fiber sponges. Specifically, a variety of 3D fibrous sponges were constructed by the 3D reconstruction of electrospun fiber membranes, including embedded hydrogels, 3D printing, gas-foaming, and freeze-drying methods. Meanwhile, the direct electrospinning methods of 3D fibrous sponges have also been successfully developed, which are mainly divided into layer-by-layer stacking, liquid-assisted collection, 3D template collection, particle leaching, and humidity field regulation. Moreover, the applications of these fibrous sponges in many fields have been explored, such as sound absorption, warmth retention, thermal insulation, air filtration, adsorption/separation, and tissue engineering. These research works provide new ideas and methods for the fabrication of 3D fiber materials. Herein, the electrospinning technology and principle were briefly introduced, the representative progress of 3D fiber sponges in recent years was summarized, and their future development prospected.Graphical Abstract