scholarly journals New Methods to Electrospin Nanofibers

2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
George G. Chase ◽  
Jackapon Sunthorn Varabhas ◽  
Darrell H Reneker
Keyword(s):  
Electric Fields ◽  
Fiber Diameter ◽  
Electrospinning Process ◽  
Alternative Methods ◽  
Production Rates ◽  
Polymeric Fibers ◽  
New Methods ◽  
Blown Film ◽  
Multiple Jets ◽  
Single Jet

Electrospinning from a single jet is commonly used to produce very fine polymeric fibers. The mass production rate of the electrospinning from a single jet is relatively low. Alternative methods to launch multiple jets and increase production rates are described here. Few variations on the electrospinning process are reported in literature. In this paper we discuss three novel methods to launch polymer jets via electric fields. Multiple pendant drop electrospinning jets from porous tubes produced fibers with average fiber diameter smaller than 400 nanometers. Bubble launched electrospinning and blown-film methods also result in multiple jets but of larger fiber diameters. These processes have not been optimized to produce small fibers. The three methods here have production rates on the order of 0.03 to 9.00 g/hr per jet. These methods should be scalable.

Jet Repulsion in Multi-Jet Electrospinning Systems: From Needle to Needleless

2014 ◽  
Vol 852 ◽  
pp. 624-628 ◽  
Author(s):  
Yuan Sheng Zheng ◽  
Yong Chun Zeng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Fields ◽  
Fiber Diameter ◽  
Electrospinning Process ◽  
Experimental Results ◽  
Needleless Electrospinning ◽  
Difficult Issue ◽  
Element Method

Jet repulsion is the most difficult issue in the multineedle electrospinning process. This study aims at reducing the jet pulsion by designing the spinneret. Three different multijet electrospinning configutations are used to study the jet repulsion in multijet electrospinning process. The experimental results shows that adding a PTFE cylinder to the traditional multineedle electrospinning setup can reduce the jet repulsion, but the diameter and irregularity of the resultant fiber other increased. A needleless electrospinning setup using a multihole plate to replace the needles can reduce jet repulsion effectively, reduce fiber diameter and irregularity as well. And the electric fields of the three electrospinning configurations are simulated by finite element method to explain the experiment results.

scholarly journals Study of Nanofiber Formation by Injecting Polymeric Solutions Inside Intense Electric Fields Using Different Electrode Configurations

2010 ◽  
Vol 5 (2) ◽  
pp. 148-153
Author(s):  
R. Furlan ◽  
S. V. Arroyo ◽  
R. O. F. Torres ◽  
J. A. M. Rosado ◽  
A. N. R. Da Silva
Keyword(s):  
Electric Fields ◽  
Fiber Orientation ◽  
Electrostatic Interactions ◽  
Fiber Diameter ◽  
Electrospinning Process ◽  
Floating Potential ◽  
Polymer Injection ◽  
Polymer Flow ◽  
Polymeric Solutions ◽  
Diameter Reduction

Electrospinning has been considered a straightforward way of producing nanofibers. In this work we are analyzing non-conventional approaches of the electrospinning process to better understand and explore the effect of electrostatic interactions. The processes we are investigating include the insertion of polymer inside the electric field keeping the capillary for polymer injection at a floating potential. Also, we are investigating different electrode configurations including: same as electrospinning (with and without polarization of the capillary for polymer injection), parallel macro electrodes and, microelectrodes (with tip to tip alignment). Image analysis reveals the occurrence of instabilities/oscillations of the polymer flow (caused by redistribution of charges). Improvement of polymer flow directionality and fiber diameter reduction are observed in comparison with conventional electrospinning. Fiber orientation can be obtained using parallel macro electrodes and micro electrodes.

scholarly journals Optimization of The Electrospinning Process for Preparation of Nanofibers From Poly (Vinyl Alcohol) (PVA) and Chromolaena odorata L. Extrac (COE)

2020 ◽  
Vol 16 (1) ◽  
pp. 47-56
Author(s):  
I. Sriyanti ◽  
L. Marlina ◽  
J. Jauhari
Keyword(s):  
Wound Dressing ◽  
Fiber Diameter ◽  
Sem Analysis ◽  
Electrospinning Process ◽  
The Body ◽  
Poly Vinyl Alcohol ◽  
Therapeutic Effects ◽  
Important Process ◽  
Chromolaena Odorata ◽  
Solubility In Water

The Cromaloena odorata (COE) contains phenols, flavonoids, tannins, alkaloids, saponins, steroids that possess diverse therapeutic effects. However, COE has poor solubility in water and poor absorbtion in the body. Incorporation of COE in nanofiber system is a promising way to increase CEO solubility. One of the method to produce nanofiber is electrospinning. The electrospinning process there are three of the most important process parameters are applied flowrate, voltage and TCD. In this study we developed optimized condition for electrospinning process of polyvinyl alcohol (PVA)/CEO and their characterization. The Scanning electron microscopy (SEM) analysis showed that modification of flowrate and TCD did not affect the morphology of PVA and COE fiber. However fiber diameter decreased when lower flowrate, higher voltage was applied, and TCD. Fourier Transform Infrared (FTIR) study was conducted to identify possible intermolecular interaction between PVA/COE that has potential application as antimicrobial wound dressing.

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

scholarly journals A Sulfur Copolymers (SDIB)/Polybenzoxazines (PBz) Polymer Blend for Electrospinning of Nanofibers

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1526 ◽  
Author(s):  
Ronaldo P. Parreño ◽  
Ying-Ling Liu ◽  
Arnel B. Beltran
Keyword(s):  
Polymer Blend ◽  
Single Phase ◽  
Fiber Diameter ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Sem Images ◽  
Water Contact ◽  
Fixed Concentration ◽  
New Material ◽  
Nanofiber Mats

This study demonstrated the processability of sulfur copolymers (SDIB) into polymer blend with polybenzoxazines (PBz) and their compatibility with the electrospinning process. Synthesis of SDIB was conducted via inverse vulcanization using elemental sulfur (S8). Polymer blends produced by simply mixing with varying concentration of SDIB (5 and 10 wt%) and fixed concentration of PBz (10 wt%) exhibited homogeneity and a single-phase structure capable of forming nanofibers. Nanofiber mats were characterized to determine the blending effect on the microstructure and final properties. Fiber diameter increased and exhibited non-uniform, broader fiber diameter distribution with increased SDIB. Microstructures of mats based on SEM images showed the occurrence of partial aggregation and conglutination with each fiber. Incorporation of SDIB were confirmed from EDX which was in agreement with the amount of SDIB relative to the sulfur peak in the spectra. Spectroscopy further confirmed that SDIB did not affect the chemistry of PBz but the presence of special interaction benefited miscibility. Two distinct glass transition temperatures of 97 °C and 280 °C indicated that new material was produced from the blend while the water contact angle of the fibers was reduced from 130° to 82° which became quite hydrophilic. Blending of SDIB with component polymer proved that its processability can be further explored for optimal spinnability of nanofibers for desired applications.

scholarly journals Designing Multifunctional Protective PVC Electrospun Fibers with Tunable Properties

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2086
Author(s):  
Pedro J. Rivero ◽  
Iker Rosagaray ◽  
Juan P. Fuertes ◽  
José F. Palacio ◽  
Rafael J. Rodríguez
Keyword(s):  
Fiber Diameter ◽  
Electrospinning Process ◽  
Operating Parameters ◽  
Electrospun Fibers ◽  
Polymeric Precursor ◽  
Operational Parameters ◽  
Electrospinning Technique ◽  
Coating Morphology ◽  
Hydrophobic Nature ◽  
First Time

In this work, the electrospinning technique is used for the fabrication of electrospun functional fibers with desired properties in order to show a superhydrophobic behavior. With the aim to obtain a coating with the best properties, a design of experiments (DoE) has been performed by controlling several inputs operating parameters, such as applied voltage, flow rate, and precursor polymeric concentration. In this work, the reference substrate to be coated is the aluminum alloy (60661T6), whereas the polymeric precursor is the polyvinyl chloride (PVC) which presents an intrinsic hydrophobic nature. Finally, in order to evaluate the coating morphology for the better performance, the following parameters—such as fiber diameter, surface roughness (Ra, Rq), optical properties, corrosion behavior, and wettability—have been deeply analyzed. To sum up, this is the first time that DoE has been used for the optimization of superhydrophobic or anticorrosive surfaces by using PVC precursor for the prediction of an adequate surface morphology as a function of the input operational parameters derived from electrospinning process with the aim to validate better performance.

Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates

1996 ◽  
Vol 81 (4) ◽  
pp. 1754-1761 ◽  
Author(s):  
Jon K. Moon ◽  
Nancy F. Butte
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Carbon Dioxide Production ◽  
Alternative Methods ◽  
Prediction Errors ◽  
Nonlinear Functions ◽  
Production Rates ◽  
Basal Energy Expenditure

Moon, Jon K., and Nancy F. Butte. Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates. J. Appl. Physiol.81(4): 1754–1761, 1996.—Oxygen consumption (V˙o 2) and carbon dioxide production (V˙co 2) rates were measured by electronically recording heart rate (HR) and physical activity (PA). Mean daily V˙o 2 andV˙co 2 measurements by HR and PA were validated in adults ( n = 10 women and 10 men) with room calorimeters. Thirteen linear and nonlinear functions of HR alone and HR combined with PA were tested as models of 24-h V˙o 2 andV˙co 2. Mean sleepV˙o 2 andV˙co 2 were similar to basal metabolic rates and were accurately estimated from HR alone [respective mean errors were −0.2 ± 0.8 (SD) and −0.4 ± 0.6%]. The range of prediction errors for 24-h V˙o 2 andV˙co 2 was smallest for a model that used PA to assign HR for each minute to separate active and inactive curves (V˙o 2, −3.3 ± 3.5%; V˙co 2, −4.6 ± 3%). There were no significant correlations betweenV˙o 2 orV˙co 2 errors and subject age, weight, fat mass, ratio of daily to basal energy expenditure rate, or fitness. V˙o 2,V˙co 2, and energy expenditure recorded for 3 free-living days were 5.6 ± 0.9 ml ⋅ min−1 ⋅ kg−1, 4.7 ± 0.8 ml ⋅ min−1 ⋅ kg−1, and 7.8 ± 1.6 kJ/min, respectively. Combined HR and PA measured 24-h V˙o 2 andV˙co 2 with a precision similar to alternative methods.

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