Hierarchical Design Strategies to Produce Internally Structured Nanofibers

Abstract

Nanofibers have attracted significant interest due to their unique properties such as high specific surface area, high aspect ratio, and spatial interconnectivity. Nanofibers can exhibit multifunctional properties and unique opportunities for promising applications in a wide variety of fields. Hierarchical design strategies are being used to prescribe the internal structure of nanofibers, such as core-sheath, concentric layers, particles distributed randomly or on a lattice, and cocontinuous network phases. This review presents a comprehensive overview of design strategies being used to produce the next generation of nanofiber systems. It includes a description of nanofiber processing methods and their effects on the nano-and microstructure. Physico-chemical effects, such as self-assembly and phase separation, on the ultimate morphology of fibers made from designed emulsions, polymer blends, and block copolymers, are then described. This review concludes with perspectives on existing challenges and future directions for hierarchical design strategies to produce internally structured nanofibers.

Self-Assembled Graft Copolymer Nanofibers with an Adjustable Internal and External Structure

“…Nanofibers are prolate aggregates with significantly high length-to-width ratio and with a diameter ranging from a few nanometers to micron. 1 Unique properties of these structures, along with the ability to form two-and three-dimensional scaffolds with adjusted morphology, highlight the prospects for their use in both tissue engineering and composite materials. 1−4 The main examples of fiber materials are provided by nature itself�scaffolds of every biological tissue, extracellular matrices (ECM), are, in fact, complex physical networks, consisting of fibers made up of polypeptides and polysaccharides.…”

“…Nanofibers are prolate aggregates with significantly high length-to-width ratio and with a diameter ranging from a few nanometers to micron . Unique properties of these structures, along with the ability to form two- and three-dimensional scaffolds with adjusted morphology, highlight the prospects for their use in both tissue engineering and composite materials. − …”

“…One of the promising ways to produce nanofibers with controllable inner morphology is a self-assembly of amphiphilic copolymers. ,− Surface activity of this class of polymers under the right conditions can lead to the formation of aggregates with an elongated cylindrical structure, while incompatibility of chemically distinct monomers can induce microphase separation in the bulk of nanofibers with different yet adjustable outcomes. ,− …”