New Insight into Gap Electrospinning: Toward Meter-long Aligned Nanofibers

Abstract

Gap electrospinning is a facile technique to produce aligned nanofibers useful for many applications, but its potential has not yet been fully exploited in nature, leading to the fiber length still limited to several tens of centimeters at present. In this work, we report a breakthrough in the production of well-aligned nanofibers with record length and efficiency. Using a suitable poly(vinylidene fluoride) solution and a pair of parallel plates that are substrate-free and negatively connected, we demonstrate the ease of this technique to prepare length-controllable aligned fibers in a wide range (≤125 cm). Because of the crucial roles of both the jet whipping instability that continuously drives the jet to span across the static plates and the negative voltage on the plates that effectively attracts the positively charged jet, the jet can be made to move back and forth over the superlarge gap to form ultralong aligned nanofibers. By introducing a projection method, we also redefine fiber alignment in a broader sense. This work is believed to provide a new insight into the nature of gap electrospinning, which will greatly expand the versatility of this technique to create devices for a myriad of applications.

Facile Preparation of Superhydrophobic Membrane Inspired by Chinese Traditional Hand-Stretched Noodles

“…Poly(vinylidene fluoride) (PVDF; an electroactive polymer that we have widely investigated previously [21,22]) and candle soot were chosen for the solution electrospinning and superhydrophobic nanopowders, respectively. The preparation of candle soot and superhydrophobic PVDF membranes is illustrated in Figure 1.…”

Topographical and Biomechanical Guidance of Electrospun Fibers for Biomedical Applications

“…To control the fiber alignment, flat collectors that are typically used in the basic setup configuration, can be replaced by rotating collectors (i.e., mandrels, wheels) that allow to preferentially impart fiber orientation by finely controlling rotation rates, from tens to thousands rpm [22,23]. Alternative methodologies to achieve aligned fibers concerns the use of "gap" collectors, which consist in the use of two conductive electrodes placed in parallel at a predefined distance, i.e., a gap from hundreds of micrometers to several centimeters, wherein local electric forces are able to arrange the charged fibers along preferential ways until to span the gap [23,24]. In the case of composite nanofibers embedded with magnetic particles, gap can be alternatively formed by the use of two permanent magnets that allow guiding the deposition of fibers along preferential ways by the application of magnetic forces on magnetically susceptive nanoparticles [25].…”

Elaboration and characterization of P3HT–PEO–SWCNT fibers by electrospinning technique

“…Katta et al [4], used copper wires in the form of a circular drum as collector which allows to obtain aligned fibers widely manipulated. Lei et al [5], used a collector with parallel plates connected negatively, this collector allows to obtain well aligned fibers of great length. Recently, works on the molecular orientation along the fiber have been carried out.…”

“…Recently, works on the molecular orientation along the fiber have been carried out. Kakade et al [6], have investigated that the molecular orientation induced by an electric field can be performed, which produces a high degree of orientation of the main polymer chains along the fiber axis. Bounioux et al have studied the effects of the CNT dispersion in P3AT and the preparation of single wall carbon nanotubes (SWCNT)-phenyl-C61-butyric acid methyl ester (PCBM)-P3HT fibers via electrospinning [2,7,8], finding the feasibility for optoelectrical applications.…”