Fabrication of Biaxially Aligned Nanofibers via Insulating Block-Assisted Electrospinning and Their Applications

Electrospinning is a well-established and widely adopted process for producing fine and continuous nanofiber networks. Electrospun nanofibers have gained significant attention owing to their advantages, including nanoscale fiber uniformity, tunable pore size with bimodal distribution, and versatility in integrating various inorganic and organic compositions. Recently, considerable efforts have been made to align nanofibers and enhance their functionality with improved mechanical properties, faster charge transport, and more efficient mass transport in well-organized spatial structures. This mini-review highlights the fabrication of precisely aligned nanofibers using insulating block-assisted electrospinning. By manipulating the electric field between the nozzle and substrate, combined with a moving substrate, insulating block-assisted electrospinning enables the biaxial alignment of the nanofibers. This review discusses recent advancements in insulating block-assisted alignment techniques and explores the applications of these aligned nanofibers in the environmental and energy fields, including air filtration media, lithium-ion battery electrodes, hybrid gel polymer electrolytes for aqueous batteries, and reinforced composite membranes for fuel cells. In addition, the perspectives associated with the extension of insulating block-driven aligned nanofiber applications to a wide range of fields and industries is summarized.