scholarly journals Needleless Electrospinning of Uniform Nanofibers Using Spiral Coil Spinnerets

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Wang ◽  
Haitao Niu ◽  
Xungai Wang ◽  
Tong Lin
Keyword(s):  
Electric Field ◽  
Production Rate ◽  
Applied Voltage ◽  
Fiber Diameter ◽  
Wire Diameter ◽  
Minor Effect ◽  
Electrospinning Technique ◽  
Fiber Production ◽  
Needleless Electrospinning ◽  
Coil Diameter

Polyvinyl alcohol nanofibers were prepared by a needleless electrospinning technique using a rotating spiral wire coil as spinneret. The influences of coil dimension (e.g., coil length, coil diameter, spiral distance, and wire diameter) and operating parameters (e.g., applied voltage and spinning distance) on electrospinning process, nanofiber diameter, and fiber productivity were examined. It was found that the coil dimension had a considerable influence on the nanofiber production rate, but minor effect on the fiber diameter. The fiber production rate increased with the increased coil length or coil diameter, or the reduced spiral distance or wire diameter. Higher applied voltage or shorter collecting distance also improved the fiber production rate but had little influence on the fiber diameter. Compared with the conventional needle electrospinning, the coil electrospinning produced finer fibers with a narrower diameter distribution. A finite element method was used to analyze the electric field on the coil surface and in electrospinning zone. It was revealed that the high electric field intensity was concentrated on the coil surface, and the intensity was highly dependent on the coil dimension, which can be used to explain the electrospinning performances of coils. In addition, PAN nanofibers were prepared using the same needleless electrospinning technique to verify the improvement in productivity.

Finite Element Analysis and Optimization of Electric Field Structure of New-Type Electrospinning Machine

2011 ◽  
Vol 279 ◽  
pp. 214-218 ◽  
Author(s):  
Hong Wei Duan ◽  
Jin Gang Jiang
Keyword(s):  
Electric Field ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Fiber Diameter ◽  
Woven Fabric ◽  
Electrospinning Technique ◽  
Element Analysis ◽  
New Type ◽  
Field Device ◽  
Original Device

Electrospinning technique is currently one of the most important methods for preparing nanofiber. Aiming to the fact that the electric field at the receiver is relatively weak, the electric field’s distribution in the typical electrospinning device was calculated and analyzed by ANSYS. It put forward the method of optimizing electric field’s distribution by using an assistant electric field device. At the same boundary conditions, the electric field’s distribution in the original device and improved binode device are compared. The simulation analysis provides an effective reference for the optimization design of electric field’s distribution in the electro-spinning device. The experimentation results show that the distribution of fiber diameter of polyimide non-woven fabric is equal and has a certain directivity after adding assistant electric field.

Investigation of a New Needleless Electrospinning Method for the Production of Nanofibers

2013 ◽  
Vol 8 (4) ◽  
pp. 155892501300800 ◽  
Author(s):  
Deogratias Nurwaha ◽  
Wanli Han ◽  
Xinhou Wang
Keyword(s):  
Strong Interaction ◽  
Applied Voltage ◽  
Fiber Diameter ◽  
Electrospun Fiber ◽  
Scaling Up ◽  
Processing Parameters ◽  
Needleless Electrospinning ◽  
Electrospinning Method ◽  
Multiple Jets ◽  
Productivity Rate

This paper presents the possibility of nanofiber formation by a new multiple jet method. A novel needleless electrospinning apparatus was used to produce nanofibers. This employs a new design for supplying solution to a metal roller spinneret. The advantage of this setup is its ease of scaling-up for increased output. Using this new method it was possible to increase the nanofiber production rate because of the multiple jets. The productivity rate has been significantly enhanced and was 24–30 times higher than single needle electrospinning. It was also possible to produce thinner fibers than the single needle method. It was found that fibers produced by this novel needleless electrospinning had fewer beadings than fibers produced by the conventional electrospinning method. The effects of processing parameters including applied voltage and spinning electrospinning distance on eletrospun fiber diameter were also investigated. The study showed that the electrospun fiber diameter was strongly governed by the processing parameters. It was observed that there was a strong interaction between these parameters.

scholarly journals Influence of the Protein Content on Fiber Morphology and Heat Treatment of Electrospun Potato Protein–Maltodextrin Fibers

2021 ◽  
Vol 11 (17) ◽  
pp. 7896
Author(s):  
Monika Gibis ◽  
Franziska Pribek ◽  
Ines Kutzli ◽  
Jochen Weiss
Keyword(s):  
Thermal Treatment ◽  
Protein Content ◽  
Production Rate ◽  
Fiber Diameter ◽  
Average Diameter ◽  
Diameter Distribution ◽  
Fiber Morphology ◽  
Potato Protein ◽  
Ultrafine Fibers ◽  
Needleless Electrospinning

The production of ultrafine fibers of proteins and polysaccharides by needleless electrospinning can be performed prior to a thermal treatment to form glycoconjugates via the first stage of the Maillard reaction. The aim was to produce potato protein–maltodextrin conjugates with a varying protein content of 0.05, 0.1, 0.15, and 0.2 g/mL by needleless electrospinning and subsequent thermal treatment (0, 6, 12, 24, and 48 h at 65 °C and 75% relative humidity). The concentrations of the maltodextrins, with a dextrose equivalent of 2 and 21, were kept constant at 0.8 and 0.1 g/mL. The highest fiber production rate was achieved with a protein content of 0.1 g/mL (5.8 ± 0.4 g/h). With increasing protein content, the production rate decreased to 2.8 ± 0.5 g/h. The fibers obtained from the spinning solution containing 0.2 g/mL protein showed the largest average diameter (4.0 ± 1.5 µm) and the broadest fiber diameter distribution. The protein content of the fibers was close to that of the corresponding spinning solution. The browning index after 48 h of heating increased for all samples (9.7–14.7) compared to the unheated samples (1.1–3.3). The results indicate that the protein content has an impact on the yield, the fiber diameter, and the morphology of the fibers.

Study on Needle and Needleless Electrospinning for Nanofibers

2013 ◽  
Vol 750-752 ◽  
pp. 276-279 ◽  
Author(s):  
Wan Jun Liu ◽  
Hai Feng Zhang ◽  
Da Wei Li ◽  
Chen Huang ◽  
Xiang Yu Jin
Keyword(s):  
Stainless Steel ◽  
Polyvinyl Alcohol ◽  
Applied Voltage ◽  
Large Scale ◽  
Fiber Diameter ◽  
Water Solution ◽  
Electrospun Nanofibers ◽  
Diameter Distribution ◽  
Spiral Coil ◽  
Needleless Electrospinning

Polyvinyl alcohol (PVA) water solution was electrospun by both needle electrospinning and needleless electrospinning. The electrodes for needless electrospinning were rotary spiral disk and spiral coil made from stainless steel. We found that needleless electrospinning can obtain nanofibers in large-scale, while fiber diameter and diameter distribution were larger when compared to the conventional needle electrospinning. The average diameters of disk electrospun and coil electrospun nanofibers were 441±99nm and 415±103nm respectively. As for needle electrospun nanofibers, the diameters were 393±29nm and 349±25nm when the applied voltage were 10kV and 15kV respectively.

scholarly journals Fabrication and characterization of polyvinylidene fluoride nanofibers prepared by electrospinning technique

2021 ◽  
Vol 63 (1) ◽  
pp. 49-54
Author(s):  
Thi Thu Thuy Nguyen ◽  
◽  
The Huu Nguyen ◽  
Thi Hai Trinh ◽  
Thi Thu Trang Bui ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Feed Rate ◽  
Polyvinylidene Fluoride ◽  
Fiber Diameter ◽  
Average Diameter ◽  
Solution Concentration ◽  
Solvent Mixture ◽  
Gas Filtration ◽  
Hydrophobic Property ◽  
Electrospinning Technique

Electrospinning is a technique that produces polymer fibers with diameters in the submicron range. In this study, some electrospinning parameters affecting the morphology, average diameter, and distribution of the diameter of polyvinylidene fluoride (PVDF) fibers were investigated by using scanning electron microscopy (SEM). These electrospinning parameters include solution concentration, applied voltage, the feed rate of solution, distance from the needle to the collector, and solvent mixture. PVDF fibers have a fine structure, narrow distribution of fiber diameter, and average fiber diameter of 736 nm at a solution concentration of 20 wt%, solvent mixture with 60/40 weight of N,N-dimethylacetamide (DMAc) and acetone (Ac), an applied voltage of 11 kV, the feed rate of 1 ml/h, and the distance from the needle to the collector of 17 cm. The hydrophobic property and tensile strength of the PVDF nanofiber membrane were also reported. PVDF nanofibers have the potential to apply in several areas such as water or gas filtration, catalyst, lithium battery, ect.

Needleless electrospinning of PVP/PGS fibrous scaffolds for skin tissue engineering applications

2018 ◽  
Author(s):  
Antonios Keirouz ◽  
Giuseppino Fortunato ◽  
Anthony Callanan ◽  
Norbert Radacsi
Keyword(s):  
Tissue Engineering ◽  
Tensile Modulus ◽  
Dermal Fibroblasts ◽  
Skin Tissue ◽  
Skin Substitute ◽  
Electrospinning Technique ◽  
Skin Tissue Engineering ◽  
Needleless Electrospinning ◽  
High Concentrations

Scaffolds and implants used for tissue engineering need to be adapted for their mechanical properties with respect to their environment within the human body. Therefore, a novel composite for skin tissue engineering is presented by use of blends of Poly(vinylpyrrolidone) (PVP) and Poly(glycerol sebacate) (PGS) were fabricated via the needleless electrospinning technique. The formed PGS/PVP blends were morphologically, thermochemically and mechanically characterized. The morphology of the developed fibers related to the concentration of PGS, with high concentrations of PGS merging the fibers together plasticizing the scaffold. The tensile modulus appeared to be affected by the concentration of PGS within the blends, with an apparent decrease in the elastic modulus of the electrospun mats and an exponential increase of the elongation at break. Ultraviolet (UV) crosslinking of PGS/PVP significantly decreased and stabilized the wettability of the formed fiber mats, as indicated by contact angle measurements. In vitro examination showed good viability and proliferation of human dermal fibroblasts over the period of a week. The present findings provide important insights for tuning the elastic properties of electrospun material by incorporating this unique elastomer, as a promising future candidate for skin substitute constructs.

scholarly journals Axion assisted Schwinger effect

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Valerie Domcke ◽  
Yohei Ema ◽  
Kyohei Mukaida
Keyword(s):  
Electric Field ◽  
Production Rate ◽  
Strong Electric Field ◽  
Background Field ◽  
Chiral Anomaly ◽  
Fermion Mass ◽  
Anomaly Equation ◽  
Electric And Magnetic Fields ◽  
Schwinger Effect ◽  
Momentum Transverse

Abstract We point out an enhancement of the pair production rate of charged fermions in a strong electric field in the presence of time dependent classical axion-like background field, which we call axion assisted Schwinger effect. While the standard Schwinger production rate is proportional to $$ \exp \left(-\pi \left({m}^2+{p}_T^2\right)/E\right) $$ exp − π m 2 + p T 2 / E , with m and pT denoting the fermion mass and its momentum transverse to the electric field E, the axion assisted Schwinger effect can be enhanced at large momenta to exp(−πm2/E). The origin of this enhancement is a coupling between the fermion spin and its momentum, induced by the axion velocity. As a non-trivial validation of our result, we show its invariance under field redefinitions associated with a chiral rotation and successfully reproduce the chiral anomaly equation in the presence of helical electric and magnetic fields. We comment on implications of this result for axion cosmology, focussing on axion inflation and axion dark matter detection.

TiO2 nanofibers fabricated by electrospinning technique and degradation of MO dye under UV light

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Naveen Thakur ◽  
Nikesh Thakur ◽  
Viplove Bhullar ◽  
Saurabh Sharma ◽  
Aman Mahajan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fiber Diameter ◽  
Uv Light ◽  
Rutile Phase ◽  
Powder Form ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Tio2 Nanofibers ◽  
X Ray ◽  
Uv Visible

Abstract Titanium dioxide (TiO2) nanofibers were synthesized by electrospinning to optimize the photocatalytic action efficiency. The synthesis of the fibers was carried out at four different wt% concentrations: 8, 9, 10 & 11% of polymer polyvinylpyrrolidone (PVP). The TiO2 fibers were further calcined at 700 °C to get powder form. The uncalcinated and calcined TiO2 nanofibers were characterized by using X-Ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) and UV-Visible spectroscopy. Raman spectroscopy confirmed the rutile phase of the calcined TiO2nanofibers in powder form with a crystallite size of 34–38 nm. The surface morphology of the uncalcinated and calcined TiO2 nanofibers was examined by SEM and the fiber diameter found to be 360–540 nm. The optical bandgap of the calcined TiO2 nanofibers was found in the range of 3.29–3.24 eV. The photocatalytic activity of the TiO2 nanofibers as examined for uncalcinated and calcined nanofibers, methyl orange (MO) dye degraded up to 98 and 78%, respectively in 180 min under the exposure of UV light. Uncalcinated TiO2 nanofibers were found more suitable for degradation of MO dye as compared to calcined nanofibers.

scholarly journals Electrospun Nylon-6 Nanofibers and Their Characteristics

2020 ◽  
Vol 9 (1) ◽  
pp. 9-19
Author(s):  
Ida Sriyanti ◽  
Meily P Agustini ◽  
Jaidan Jauhari ◽  
Sukemi Sukemi ◽  
Zainuddin Nawawi
Keyword(s):  
Fiber Diameter ◽  
Peak Shift ◽  
Nylon 6 ◽  
Electrospinning Process ◽  
Electrospinning Technique ◽  
Fiber Concentration ◽  
Air Filters ◽  
Xrd Pattern ◽  
Electrospinning Method ◽  
Small Wave

The purposes of this research were to investigate the synthesized Nylon-6 nanofibers using electrospinning technique and their characteristics. The method used in this study was an experimental method with a quantitative approach. Nylon-6 nanofibers have been produced using the electrospinning method. This fiber was made with different concentrations, i.e. 20% w/w (FN1), 25% w/w (FN2), and 30% w/w (FN3). The SEM results show that the morphology of all nylon-6 nanofibers) forms perfect fibers without bead fiber. Increasing fiber concentration from 20% w/w to 30% w/w results in bigger morphology and fiber diameter. The dimensions of the FN1, FN2, and FN3 fibers are 1890 nm, 2350 nm, and 2420 nm, respectively. The results of FTIR analysis showed that the increase in the concentration of nylon-6 (b) and the electrospinning process caused a peak shift in the amide II group (CH2 bond), the carbonyl group and the CH2 stretching of the amide III group from small wave numbers to larger ones. The results of XRD characterization showed that the electrospinning process affected the changes in the XRD pattern of nylon-6 nanofiber (FN1, FN2, and FN3) in the state of semi crystal. Nylon-6 nanofibers can be used for applications in medicine, air filters, and electrode for capacitors

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