The combination of electrospinning and extrusion based 3D printing opens new pathways for micro- and nanofabrication in a wide range of applications. The fast production of a highly stable self-standing polystyrene 3D structure is demonstrated.

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The combination of electrospinning with 3D printing technology opens new pathways for nano- and microfabrication, which can be applied in a wide range of application. This simple and inexpensive method was proven to fabricate 3D fibrous polystyrene structures with controlled morphology and micro to nano-fibre diameter. The controllable movement of the nozzle allows precise positioning of the deposition area of the fibres during electrospinning. A programmed circular nozzle pattern results in the formation of 3D polystyrene cylinder shapes with fibre diameters down to 560 nm. The assembly of the fibrous structures starts instantaneously, and a 4 cm tall and 5 cm wide sample can be produced within a 10-minute electrospinning process. The product exhibits high stability at ambient conditions. The shape, size, and thickness of fibrous polystyrene structures can be easily controlled by tuning the process parameters. It is assumed that the build-up of 3D fibrous polystyrene structure strongly depends on charge induction and polarization of the electrospun fibres.

The flame retardancy of FPUFs can be enhanced by the manipulation of the solid-polymer interface chemistry.

This paper reports on the rapid fabrication of radially-aligned, three-dimensional conical structures by electrospinning. Three different polymers, Polyvinylpyrrolidone, Polystyrene and Polyacrylonitrile were used to electrospin the cones. These cone structures are spreading out from a vertical conductive pillar, which can be arbitrarily placed on specific part of the collector. The lower part of the cone is clearly defined on the collector, and the cone has a relatively uniform radius around the pillar. The cones are constituted of fibers that are radially aligned towards the top of the pillar, but there is no apex and the fibers fall flat on the top of the pillar surface. A parametric study has been performed to investigate the effects of the pillar morphology (height and thickness) and the electrospinning parameters (applied voltage and working distance) on the overall shape and size of the cone structure, as well as the fiber alignment. The pillar morphology influences directly the cone diameter and height. The electrospinning parameters have little effect on the cone structure. The formation mechanism has been identified to be related to the shape of the electric field, which has been systematically simulated to understand the effect of the electric field lines on the final dimensions of the cone structure.

Self-standing carbon fiber electrodes hold promise for solid-state battery technology owing to their networked structures improving interparticle connectivity, robustness contributing to mechanical integrity, and surface sites confining Li dendrites. We here evaluate carbonized 3D electrospun fibers filled with polymer electrolytes as anodes in solid-state lithium half cells. Microscopic analysis of the cells demonstrates the high wettability of carbon fibers with electrolytes, promoting an intimate contact between electrolytes and fibers. Solid-state cells delivered high initial capacities up to ∼300 mAh g−1, although the latter cycles were characterized by gradual capacity fade (∼100 mAh g−1 in the 100th cycle with nearly 100% coulombic efficiency), attributed to the onset of parasitic reactions increasing the cell resistance and polarization. When these were benchmarked against similar cells but with the liquid electrolyte, it was found that Li storage in these fiber electrodes is intermediate between graphite and hard carbon in terms of lithiation voltage (vs Li/Li+), corroborating with the nature of carbon assessed by XRD and Raman analysis. These observations can contribute to further development and optimization of solid-state batteries with 3D electrospun carbon fiber electrodes.

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