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Rough structure microspheres developed using electrospinning show many superior properties, such as increased specific surface area and enhanced wettability, yielding numerous benefits to the applications in adsorption, separation, and others. In this study, biomimetic rough microspheres on string of polymethyl methacrylate nanofiber with hierarchical structure of micron-scale microsphere, and nanoscale Y-shape edges on the microsphere were innovatively and successfully developed by electrospinning. The resulting microsphere exhibited a steering-wheel-like Y shape, and the formation process was physically explained by the geometric potential theory. In the spinning process, irregular hexahedron-like droplet was firstly formed. Then, the hexahedron-like droplet changed to tetrahedron-like after the bottom contacted the collector. The tetrahedron-like droplet evolved into Y-shaped microsphere due to the geometric potential and the collapse of the center part owing to the solvent evaporation. Furthermore, similar to the natural lotus leaf, the hierarchical steering-wheel structure strengthened the nanofiber membrane roughness and endowed the membrane with superhydrophobicity, indicating the potential application in water treatment (oil-water separation, and dye and heavy metal ion adsorption), functional surface materials (self-cleaning fabrics), energy generation and other salient areas. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial evaporation system has attracted intensive attention owing to its great potential in harnessing renewable solar energy to purify water. To further enhance the solar-driven interfacial evaporation system performance, solar absorber structure with high light-thermal energy conversion efficiency is especially critical. In this work, polyvinyl pyrrolidone/poly(vinylidene fluoride co hexa fluoropropylene)/CuO-nanorods (PVP/PVDF-HFP/CuO-nanorods) membrane was prepared sequentially by electrospinning, heating and hydrothermal processes. The flexible electrospun membrane was used as the photothermal layer in the solar-driven interfacial evaporation system. The evenly distributed CuO nanorods function as solar energy absorbers. The polystyrene foam was used as an insulating layer, and filter paper was inserted in the middle of the polystyrene foam to transport water to the photothermal layer. The designed evaporator was used for the solar evaporation using pure water. As a result, the evaporation rate was 1.11 kg/m2h and the light-thermal energy conversion rate was 75.36%. The outcome of this work provides the potential of solar-driven interfacial evaporation system for water desalination and wastewater purification. [ABSTRACT FROM AUTHOR]

Herein, polyvinyl alcohol nanofibrous membrane was fabricated firstly by the high-curvature solid-needle electrospinning. The influence of electrode curvature (needle angle), spinning voltage, solution concentration and collector distance on nanofiber morphology was systematically investigated numerically and experimentally. Numerical simulation shows that the electrical field increases with the increase of spinning voltage, while decreases with the increase of needle angle and collector distance. The experimental results are consistent with the numerical results. Furthermore, the solution concentration can be used to adjust the diameter of polyvinyl alcohol nanofibers. The possible applications of the nanofiber membrane to energy generation, water treatment, and separation are also discussed. [ABSTRACT FROM AUTHOR]

Poly(vinyl alcohol) nanofibers were prepared by bubble electrospinning. After the ethanol post-treatment, poly(vinyl alcohol) nanofibers showed enhanced hydrophobicity with water contact angle change from 0 to 78.9°, and the break strength of poly(vinyl alcohol) nanofibers was dramatically improved from 8.23 MPa to 17.36 MPa. The facile strategy with improved hydrophobicity and mechanical properties of poly(vinyl alcohol) nanofibers will provide potential benefits for applications of this material, especially in filtration field. [ABSTRACT FROM AUTHOR]

This paper studies numerically the two-phase flow in the single-bubble electrospinning process by solving the modified Navier-Stokes equations under the influence of electric field, and the interface between the twofluids has been determined by using the volume of fluids method. A realizable k-ε model is used to model the turbulent viscosity. The numerical results offer in-depth insight into physical understanding of many complex phenomena which cannot be fully explained experimentally. [ABSTRACT FROM AUTHOR]