Electrospinning is a versatile and viable technique for generating ultrathin fibers. Remarkable progress has been made with regard to the development of electrospinning methods and engineering of electrospun nanofibers to suit or enable various applications. We aim to provide a comprehensive overview of electrospinning, including the principle, methods, materials, and applications. We begin with a brief introduction to the early history of electrospinning, followed by discussion of its principle and typical apparatus. We then discuss its renaissance over the past two decades as a powerful technology for the production of nanofibers with diversified compositions, structures, and properties. Afterward, we discuss the applications of electrospun nanofibers, including their use as "smart" mats, filtration membranes, catalytic supports, energy harvesting/conversion/storage components, and photonic and electronic devices, as well as biomedical scaffolds. We highlight the most relevant and recent advances related to the applications of electrospun nanofibers by focusing on the most representative examples. We also offer perspectives on the challenges, opportunities, and new directions for future development. At the end, we discuss approaches to the scale-up production of electrospun nanofibers and briefly discuss various types of commercial products based on electrospun nanofibers that have found widespread use in our everyday life.

Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications

Intermolecular And Surface Forces

Studying nature to reveal the mechanisms of special wetting phenomena in biological systems can effectively inspire the design and fabrication of functional interfacial materials with superwettability. In this Review, the historical development, new phenomena and emerging applications of superwettability systems are discussed.

Nature-inspired superwettability systems

A core-shell nanovehicle coated with a platelet membrane (PM) is developed for targeted and site-specific delivery of an extracellularly active drug and an intracellular functional small-molecular drug, leading to enhanced antitumor efficacy. This PM-coated nanovehicle can also effectively eliminate the circulating tumor cells in vivo and inhibit development of tumor metastasis.

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Anticancer Platelet‐Mimicking Nanovehicles

Nanoporous molecular frameworks are important in applications such as separation, storage and catalysis. Empirical rules exist for their assembly but it is still challenging to place and segregate functionality in three-dimensional porous solids in a predictable way. Indeed, recent studies of mixed crystalline frameworks suggest a preference for the statistical distribution of functionalities throughout the pores rather than, for example, the functional group localization found in the reactive sites of enzymes. This is a potential limitation for ‘one-pot’ chemical syntheses of porous frameworks from simple starting materials. An alternative strategy is to prepare porous solids from synthetically preorganized molecular pores. In principle, functional organic pore modules could be covalently prefabricated and then assembled to produce materials with specific properties. However, this vision of mix-and-match assembly is far from being realized, not least because of the challenge in reliably predicting three-dimensional structures for molecular crystals, which lack the strong directional bonding found in networks. Here we show that highly porous crystalline solids can be produced by mixing different organic cage modules that self-assemble by means of chiral recognition. The structures of the resulting materials can be predicted computationally, allowing in silico materials design strategies. The constituent pore modules are synthesized in high yields on gram scales in a one-step reaction. Assembly of the porous co-crystals is as simple as combining the modules in solution and removing the solvent. In some cases, the chiral recognition between modules can be exploited to produce porous organic nanoparticles. We show that the method is valid for four different cage modules and can in principle be generalized in a computationally predictable manner based on a lock-and-key assembly between modules.

Modular and predictable assembly of porous organic molecular crystals

Excessive sweat secreted from the skin often causes undesired adhesion from wetted textiles and cold sensations. Traditional hydrophilic textiles such as cotton can absorb sweat but retain it. A hydrophobic/superhydrophilic Janus polyester/nitrocellulose textile embedded with a conical micropore array with a hydrophilic inner surface that can achieve directional liquid transport (with an ultrahigh directional water transport capability of 1246%) and maintain human body temperature (2-3 °C higher than with cotton textiles) is demonstrated. When the hydrophobic polyester layer with large opening of hydrophilic conical micropores contacts the liquid, the Janus polyester/nitrocellulose textile can pump it to the superhydrophilic nitrocellulose layer through the hydrophilic conical micropores driven by capillary force. The Janus polyester/nitrocellulose textile can weaken undesired wet adhesion and heat loss due to the removal of liquid. The water wicking and air permeability of the Janus polyester/nitrocellulose textile is comparable to those of traditional cloths. This study is valuable for designing of functional textiles with directional water transport properties for personal drying and warming applications.

Bioinspired Janus Textile with Conical Micropores for Human Body Moisture and Thermal Management

Interfacial polymerization, where a chemical reaction is confined at the liquid-liquid or liquid-air interface, exhibits a strong advantage for the controllable fabrication of films, capsules, and fibers for use as separation membranes and electrode materials. Recent developments in technology and polymer chemistry have brought new vigor to interfacial polymerization. Here, we consider the history of interfacial polymerization in terms of the polymerization types: interfacial polycondensation, interfacial polyaddition, interfacial oxidative polymerization, interfacial polycoordination, interfacial supramolecular polymerization, and some others. The accordingly emerging functional materials are highlighted, as well as the challenges and opportunities brought by new technologies for interfacial polymerization. Interfacial polymerization will no doubt keep on developing and producing a series of fascinating functional materials.

Interfacial Polymerization: From Chemistry to Functional Materials.

A hierarchical assembled ITO nanowire array with both horizontal and vertical nanowire branches was fabricated as a new three-dimensional fractal nanobiointerface for efficient cancer cell capture. Comparing with ITO nanowire array without branches, this fractal nanobiointerface exhibited much higher efficiency (89% vs 67%) and specificity in capturing cancer cells and took shorter time (35 vs 45 min) to reach the maximal capture efficiency. As indicated by the immunofluorescent and ESEM images, this enhancement can be attributed to the improvement of topographical interaction between cells and the substrate. The introduction of horizontal and vertical nanowire branches makes the substrate topographically match better with cell filopodia and provides more binding sites for cell capture. The live/dead cell staining and proliferation experiments confirm that this fractal nanobiointerface displays excellent cyto-compatibility with an over 96% cell viability after capture. These results provide new insights a...

Hierarchical Nanowire Arrays as Three-Dimensional Fractal Nanobiointerfaces for High Efficient Capture of Cancer Cells

Emulsion polymerization is the most widely used synthetic technique for fabricating polymeric particles. The interfacial tension generated with this technique limits the ability to tune the topology and chemistry of the resultant particles. We demonstrate a general emulsion interfacial polymerization approach that involves introduction of additional anchoring molecules surrounding the microdroplets to synthesize a large variety of Janus particles with controllable topological and chemical anisotropy. This strategy is based on interfacial polymerization mediated by an anchoring effect at the interface of microdroplets. Along the interface of the microdroplets, the diverse topology and surface chemistry features of the Janus particles can be precisely tuned by regulating the monomer type and concentration as well as polymerization time. This method is applicable to a wide variety of monomers, including positively charged, neutrally charged, and negatively charged monomers, thereby enriching the community of Janus particles.

A general strategy to synthesize chemically and topologically anisotropic Janus particles

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Feilong Zhang

Papers

Bioinspired Janus Textile with Conical Micropores for Human Body Moisture and Thermal Management

Interfacial Polymerization: From Chemistry to Functional Materials.

Hierarchical Nanowire Arrays as Three-Dimensional Fractal Nanobiointerfaces for High Efficient Capture of Cancer Cells

A general strategy to synthesize chemically and topologically anisotropic Janus particles

Mechanically Interlocked Hydrogel–Elastomer Hybrids for On‐Skin Electronics