Effect of magnetic lens on the electrospinning whipping instability, fiber diameter and its distribution

2021 ◽  
pp. 004051752110666
Author(s):  
Peng Chen ◽  
Qihong Zhou ◽  
Jun Wang ◽  
Ge Chen
Keyword(s):  
Fiber Diameter ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Liquid Jets ◽  
Magnetic Lens ◽  
Straightforward Method ◽  
Excitation Coil ◽  
Potential Applications ◽  
Exciting Coil ◽  
Plate Type

Electrospinning is an efficient and straightforward method for producing thin fibers from various materials. Although such thin fibers have diverse potential applications, the remaining problems with electrospinning are the whipping instability (also known as bending instability) of electrically charged liquid jets of polymer nanofibers and uneven fiber diameter distribution. In this study, we report a novel magnetic lens electrospinning system and discuss the principle of reducing the fiber diameter and width of the whipping circle in this electrospinning process. The effects of three types of electrospinning devices, needle-to-plate, needle-exciting coil-to-plate, and needle-magnetic lens-to-plate types, were studied through numerical simulation to analyze the electrospinning fiber collection state. For the 12 wt% polyacrylonitrile solution, when the applied voltage was 14–20 kV, the feed rate was 0.4–0.7 ml/h, and the current applied to the excitation coil or magnetic lens was 1 A, the experimental results demonstrated that, compared with needle-to-plate-type and needle-exciting coil-to-plate-type electrospinning, needle-magnetic lens-to-plate-type electrospinning produced smaller whipping circles with thinner and more uniform fibers.

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.

Process Dynamics and Control Analysis for Electrospinning Nanofibers

2010 ◽  
Author(s):  
Xuri Yan ◽  
Michael Gevelber
Keyword(s):  
Fiber Diameter ◽  
Electrospinning Process ◽  
Open Loop ◽  
Diameter Distribution ◽  
Control Analysis ◽  
Process Dynamics ◽  
Current State ◽  
Dynamics And Control ◽  
Process Reproducibility ◽  
And Control

In many emerging, high value electrospinning applications, the diameter distribution of electrospun fibers has important implications for the product’s performance and process reproducibility. However, the current state-of-the-art electrospinning process results in diameter distribution variations, both during a run and run-to-run. To address these problems, a vision-based, open loop system has been developed to better understand the process dynamics. The effects of process parameters on fiber diameter distributions are investigated, process dynamics are identified, and the relation between measurable variables and the resulting fiber diameter distribution is analyzed.

Mechanical and Thermal Characteristics of Optimized Electrospun Nylon 6,6 Nanofibers by Using Taguchi Method

NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950139
Author(s):  
Saleh S. Abdelhady ◽  
Said H. Zoalfakar ◽  
M. A. Agwa ◽  
Ashraf A. Ali
Keyword(s):  
Fiber Diameter ◽  
Thermal Characteristics ◽  
Electrospun Nanofibers ◽  
Processing Parameters ◽  
Statistical Technique ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Solvent Ratio ◽  
Average Fiber Diameter ◽  
Nylon 6,6

This study is an attempt to optimize the electrospinning process to produce minimum Nylon 6,6 nanofibers by using Taguchi statistical technique. Nylon 6,6 solutions were prepared in a mixture of formic acid (FA) and Dichloromethane (DCM). Design of experiment by using Taguchi statistical technique was applied to determine the most important processing parameters influence on average fiber diameter of Nylon 6,6 nanofiber produced by electrospinning process. The effects of solvent/nylon and FA/DCM ratio on average fiber diameter were investigated. Optimal electrospinning conditions were determined by using the signal-to-noise (S/N) ratio that was calculated from the electrospun Nylon 6,6 nanofibers diameters according to “the-smaller-the-better” approach. The optimum Nylon 6,6 concentration (NY%) and FA/DCM ratio were determined. The morphology of electrospun nanofibers is significantly altered by FA/DCM solvent ratio as well as Nylon 6,6 concentration. The smallest diameter and the narrowest diameter distribution of Nylon 6,6 nanofibers ([Formula: see text][Formula: see text]nm) were obtained for 10 wt% Nylon 6,6 solution in 80 wt% FA and 20 wt% DCM. An increase of 118%, 280% and 26% in tensile strength, modulus of elasticity and elongation at break over as-cast was obtained, respectively. Glass transition temperature of Nylon 6,6 nanofibers were determined by using differential scanning calorimeter (DSC). Analysis of variance ANOVA shows that NY% is the most influential parameter.

Analysis of Electrospinning Nanofibers: Diameter Distribution, Process Dynamics, and Control

2008 ◽  
Author(s):  
Xuri Yan ◽  
Michael Gevelber
Keyword(s):  
Control System ◽  
Fiber Diameter ◽  
Control Strategies ◽  
Process Variations ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Process Economics ◽  
Process Dynamics ◽  
Dynamics And Control ◽  
Actuator Control

Electrospinning is a method of producing nanometer scale fibers by accelerating a jet of charged polymer solution in an electric field. In many emerging, high value electrospinning applications, such as the biomedical area, the diameter distribution of electrospun polymeric nanofibers has important implications for the product’s performance and process economics (in terms of yield and production rate). However, the current state-of-the-art electrospinning process results in unpredictable and time varying diameter distributions, both during a run and run-to-run. Thus, this work is focused on developing an appropriate control system to achieve consistent and controllable fiber diameters. Another goal of this work is to develop a better understanding of the relation between process physics and the resulting fiber diameter characteristics. To address these problems, a well instrumented and computer based actuator control system has been developed. The effects of process parameters on fiber diameter are investigated for achieving consistent and repeatable process capability. The fundamental process dynamics are identified and the relation between measurable variables and the resulting fiber diameter distribution is analyzed. This relation provides the basis of developing appropriate control strategies in order to reduce both the process variations from run-to-run and during a run.

Fabrication of Aligned PAN Nanofiber by Electrospinning with Parallel Electrode

2014 ◽  
Vol 905 ◽  
pp. 19-22 ◽  
Author(s):  
Hong Ying Liu ◽  
Lan Xu ◽  
Xiao Peng Tang ◽  
Na Si
Keyword(s):  
Polymer Solution ◽  
Fiber Diameter ◽  
Electrospun Fiber ◽  
Weight Ratio ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Optimum Weight ◽  
Fiber Diameter Distribution ◽  
Pan Nanofiber ◽  
Parallel Electrode

Electrospinning has emerged as a very attractive approach to the fabrication of nanofibers. In electrospinning process, the ability to control the alignment and arrangement of fibers is critical to achieve the designed functions. In this paper, we had successfully fabricated highly aligned PAN nanofibers by the method of parallel electrode electrospinning. The study revealed the optimum weight ratio of PAN polymer solution for aligned nanofibers was 8%-12%. Results show that the increasing of weight ratio of polymer solution can enhance the parallelism and uniformity of electrospun fiber diameter distribution.

Effect of Introducing Long Chain Branching on Fiber Diameter and Fiber Diameter Distribution in Melt Blowing Process of Polypropylene

2021 ◽  
Vol 36 (4) ◽  
pp. 403-409
Author(s):  
K. Iiba ◽  
W. Takarada ◽  
T. Kikutani
Keyword(s):  
Fiber Diameter ◽  
Viscosity Reduction ◽  
Diameter Distribution ◽  
Polymer Rheology ◽  
Melt Blowing ◽  
Melt Flow Rate ◽  
Long Chain Branching ◽  
Molten Polymers ◽  
Uniform Diameter ◽  
Long Chain

Abstract In the melt blowing process, the molten polymers extruded from nozzles are elongated by high-velocity and high-temperature air flow. In this study, with the aim of stabilizing the melt blowing process for producing nonwoven webs with fine diameter fibers, the effect of the control of polymer rheology by the introduction of either low melt flow rate (MFR) polypropylene (PP) or long chain branched PP (LCB-PP) to regular high MFR PP was investigated. Introduction of low MFR PP into regular PP increased shear viscosity and fibers of larger diameter were produced in the melt blowing process, while introduction of low MFR LCB-PP suppressed the elongational viscosity reduction with the increase of strain rate, and eventually spinning was stabilized. It was found that the blending of an optimum amount of LCB-PP to regular PP caused the stabilization of the melt blowing process. As a result, the formation of nonwoven webs consisting of fine fibers of rather uniform diameter distribution could be achieved.

scholarly journals Light-assisted electrospinning monitoring for soft polymeric nanofibers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Dario Lunni ◽  
Goffredo Giordano ◽  
Francesca Pignatelli ◽  
Carlo Filippeschi ◽  
Stefano Linari ◽  
...  
Keyword(s):  
Real Time ◽  
Electrospun Fiber ◽  
Correlation Coefficients ◽  
Experimental Tests ◽  
Electrospinning Process ◽  
Analytical Models ◽  
Diameter Distribution ◽  
Soft Systems ◽  
Light Coupling ◽  
Waveguide Length

Abstract A real-time tool to monitor the electrospinning process is fundamental to improve the reproducibility and quality of the resulting nanofibers. Hereby, a novel optical system integrated through coaxial needle is proposed as monitoring tool for electrospinning process. An optical fiber (OF) is inserted in the inner needle, while the external needle is used to feed the polymeric solution (PEO/water) drawn by the process. The light exiting the OF passes through the solution drop at the needle tip and gets coupled to the electrospun fiber (EF) while travelling towards the nanofibers collector. Numerical and analytical models were developed to assess the feasibility and robustness of the light coupling. Experimental tests demonstrated the influence of the process parameters on the EF waveguide properties, in terms of waveguide length (L), and on the nanofibers diameter distribution, in terms of mean $$\widehat{D}$$ D ^ and normalized standard deviation $$\chi$$ χ . Data analysis reveals good correlation between L and $$\widehat{D}, \chi$$ D ^ , χ (respectively maximum correlation coefficients of $${\rho }_{L,\widehat{D}}$$ ρ L , D ^ = 0.88 and $${\rho }_{L,\chi }$$ ρ L , χ = 0.84), demonstrating the potential for effectively using the proposed light-assisted technology as real-time visual feedback on the process. The developed system can provide an interesting option for monitoring industrial electrospinning systems using multi- or moving needles with impact in the scaling-up of innovative nanofibers for soft systems.

scholarly journals TWO-STEP CROSSLINKING OF PVP/GEL NANOFIBERS

2021 ◽  
Vol 2021 ◽  
pp. 164-170
Author(s):  
H.K. Güler ◽  
F.C. Çallıoğlu
Keyword(s):  
Fiber Diameter ◽  
Experimental Studies ◽  
Water Soluble ◽  
Diameter Distribution ◽  
Sem Images ◽  
Crosslinking Process ◽  
Different Temperatures ◽  
Ft Ir ◽  
Ir Analysis ◽  
Gel Polymers

In this study, it was achieved that crosslinking of PVP/GEL nanofibers with two-steps. Crosslinking is a process highly important for water-soluble polymers in terms of application areas and mechanical properties. Firstly, crosslinking of PVP polymers experimental studies were carried out via heat treatment at different temperatures and times. Then, GEL polymers were crosslinked with GTA vapour at different times. Morphological analysis was carried out via SEM images and chemical characteristics were determined via FT-IR analysis. Moreover, after the crosslinking process, SD and WL values were calculated. All results showed that before crosslinking of SEM images, nanofibers were smooth, fine and without beads. The average fiber diameter is 196 nm and the fiber diameter distribution is quite uniform. After crosslinking of SEM images, it is expected that all nanowebs will turn from fibrous surfaces to membranous. Generally, SD and WL values decrease with crosslinking time increase. According to all of the SEM images, SD and WL values, optimum conditions were determined for PVP as 4 hours at 180oC and for GEL as 24 hours. Lastly, the presence of PVP and GEL polymers in the nanofiber structure was verified chemically with FT-IR analysis.

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.

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