Optimization of meta-aramid electrospun nanofibers productivity through wire-based electrospinning setup scale up

2016 ◽  
Vol 48 (1) ◽  
pp. 236-254
Author(s):  
Oertel Aurélie ◽  
Khenoussi Nabyl ◽  
Schacher Laurence ◽  
Adolphe Dominique C ◽  
Graftieaux Hélène
Keyword(s):  
Fiber Diameter ◽  
Scale Up ◽  
Electrospun Nanofibers ◽  
Substrate Material ◽  
Electrospinning Process ◽  
Influential Factors ◽  
Morphological Properties ◽  
The Past ◽  
Electrode Wire ◽  
Nonwoven Mats

Electrospinning process has been widely used over the past decades for manufacturing nanofibers. The control of the electrospinning parameters is crucial to obtain nanofibers (nonwoven mats) with optimized morphological properties. The aim of this study is to precisely define the electrospinnability of a meta-aramid solution through wire-based electrospinning setup processing. Experiments have been conducted following a design of experiment to study the influence of each parameter. Individual effects and/or combined interactions on obtained fiber diameter and general morphology (mean fiber distribution and nonfibrous area) have been investigated. The five studied process parameters are: applied voltage, relative humidity, temperature, distance between spinning electrode wire and substrate material, and airflow going through the spinning chamber. Each parameter was varied at three levels. Significant effects of parameters have been observed. The obtained results have allowed us to determine the influential factors and reduce the domain study.

scholarly journals Fiber Generators in Needleless Electrospinning

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Haitao Niu ◽  
Tong Lin
Keyword(s):  
Production Rate ◽  
Scale Up ◽  
Electrospun Nanofibers ◽  
Scaling Up ◽  
Electrospinning Process ◽  
Recent Advances ◽  
Needleless Electrospinning ◽  
Application Potential

The conventional electrospinning often uses a needle-like nozzle to produce nanofibers with a very low production rate. Despite the enormous application potential, needle electrospun nanofibers meet difficulties in broad applications in practice, due to the lack of an economic and efficient way to scale up the electrospinning process. Recently, needleless electrospinning has emerged as a new electrospinning mode and shown ability to produce nanofibers on large-scales. It has been established that the fiber generator, also referred to as “spinneret” in this paper, in needleless electrospinning plays a key role in scaling up the nanofiber production. This paper summarizes the recent advances in the development of needleless spinnerets and their influences on electrospinning process, nanofiber quality, and productivity.

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.

Optimization of chitosan-polyvinylalcohol electrospinning process by response surface methodology (RSM)

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
A. Gholipour ◽  
S. H. Bahrami ◽  
M. Nouri
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Fiber Diameter ◽  
Sem Analysis ◽  
Electrospinning Process ◽  
Morphological Properties ◽  
Blend Ratio ◽  
Extrusion Rate ◽  
Mathematical Techniques ◽  
Good Agreement

AbstractResponse Surface Methodology (RSM) is a collection of statistical and mathematical techniques useful for developing, improving, and optimizing processes. RSM was used to model and optimize the electrospinning parameters for the spinning of blend CS/PVA nanofibers. In this study, chitosan (CS)/polyvinyl alcohol (PVA) blend solutions (CS (Mw =1 X 106) in 2% acetic acid and PVA (Mw=12 X 103) in deionized water) with different blend ratio ranging from 10/90 to 50/50 were electrospun. CS/PVA (25/75) blend ratio was chosen as base and optimum ratio due to its suitable morphological properties and diameter. In a constant ratio of blend SEM analysis shows that the diameter of nanofibers changed by varying the voltage and extrusion rate in the electrospinning process. Voltage (10-25 KV) and polymer solutions extrusion rate of (0.2-1 ml/hr) from the nozzle were chosen as variables to control the fiber diameter at similar spinning distances (10 cm). Fiber diameter was correlated to production variables by using a second order polynomial function. The predicted fiber diameters were in good agreement with the experimental results.

Parametric Investigations on the Effect of Electrospinning Process Variables on the Macroscopic Properties of Hybrid Composites

2009 ◽  
Author(s):  
Sachin Shendokar ◽  
Ajit Kelkar ◽  
Ram Mohan ◽  
Ron Bolick
Keyword(s):  
Process Parameters ◽  
Fiber Diameter ◽  
Hybrid Composites ◽  
Process Variations ◽  
Electrospinning Process ◽  
Morphological Properties ◽  
Electrospun Fibers ◽  
Collector Plate ◽  
Structural Applications ◽  
Macroscopic Properties

Electrospinning is regarded as an efficient process to form sub-micron and nano level fibers consistently in a simple laboratory scale setup. The process has excellent potential for scalability and for the structural applications of integrated electrospun fibers in polymer hybrid composites. In our on going work, the mechanical characterization of these hybrid composites with integrated electrospun fibers revealed significant variations based on the sintering temperature and the morphology of the formed electrospun fibers. The morphology (in particular, the fiber diameter) depends on the process parameters of the electrospinning process. This paper investigates the influence of two electrospinning parameters namely: Distance between spinneret and collector plate and voltage. Four voltage levels were selected varying from 15KV to 18 KV in the increments of 1KV. The spinneret to the collector plate distance was varied from 70 mm to 100 mm in 10 mm increments. Thus, a total 16 combinations of these parameters were studied keeping other parameters constant. The objective is to find the optimal voltage and distance combinations that produce smallest electrospun nano fiber diameters consistently. From each voltage-distance combination, the diameter of the deposited fibers was sampled at 50 different points using the morphological image data obtained with a scanning electron microscope (SEM). The analysis of experimental data indicated four favorable voltage-distance combinations that give smallest diameter size of electrospun nano fibers consistently. These four set of parameters were, 15KV and 70 mm; 15KV and 100 mm; 18 KV and 70 mm; and 18KV and 100 mm. The least diameter of fiber was observed and measured for a voltage distance combination of 18KV and 70 mm. The least diameter observed for these parameters can be attributed to the higher applied voltage resulting into higher bending instability causing the reduction in diameter of fibers. Another reason for reduction in fiber diameter is, when the distance between spinneret and collector is increased there is more space for elongation of fibers. With more increase in length of fiber, there is higher reduction in diameter of electrospun fibers. To correlate these process variations of electrospinning to the morphological properties of electrospun fibers, design of experiments study was carried out. It has been attempted here to investigate if there is any correlationship between the morphological property of electrospun fibers and properties of two phase composite. These investigations will provide an insight on the relationship between the process parameters — morphology — and the associated characterized macroscopic properties of the formed composites. Results from the stochastic modeling for variations in the fiber diameter due to the variations in the voltage and the distance correlate well to the ARMA (6,5) stochastic model. Greens functions for the model were derived and showed the stability of the electrospinning process.

Determinants of Trading Decision: An Experiential Examination

GIS Business ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. 1-9
Author(s):  
Gunjan Sharma ◽  
Tarika Singh ◽  
Suvijna Awasthi
Keyword(s):  
Stock Market ◽  
Capital Markets ◽  
Capital Market ◽  
Capital Mobility ◽  
Influential Factors ◽  
Herd Behavior ◽  
Human Beings ◽  
The Past ◽  
The Government ◽  
Indian Stock Market

In the midst of increasing globalization, the past two decades have observed huge inflow of outside capital in the shape of direct and portfolio investment. The increase in capital mobility is due to contact between the different economies across the globe. The growing liberalization in the capital market leads to the growth of various financial products and services. Over the past decade, the Indian capital market has witnessed numerous changes in the direction of developing the capital markets more robust. With the growing Indian economy, the larger inflow of funds has been fetched into the capital markets. The government is continuously working on investor’s education in order to increase retail participation in the Indian stock market. The habits of the risk-averse middle class have been changing where these investors started participating in the Indian stock market. It is an explored fact that human beings are irrational and considering this fact becomes imperative to investigate factors that influence the trading decisions. In this research, ‘an attempt has been made to investigate various factors that affect the individual trading decision’. The data has been collected from various stockbroking firms and from clients of those stockbroking firms their opinions were recorded by means of a questionnaire. Data collected through the structured questionnaire, 33 questions were prepared which was given to the 330 respondents on the basis of convenience sampling out of which 220 individuals filled questionnaire, the total of 200 questionnaires was included in the study after eliminating the incomplete questionnaire. Various factors are being explored from the literature and then with the help of factor analysis some of the most influential factors have been explored. Factors like overconfidence, optimism, cognitive bias, herd behavior, advisory effect, and idealism are the factors which influenced the trading decision of the investors the most. Such kind of a study is contributing in the area of behavioral finance as a trading decision is an important aspect while investing in the stock market. And this kind of study would be helping and assisting financial advisors to strategies for their clients in making the right allocation and also the policy maker and market regulators to come up with better reforms for the Indian stock markets.

Formulation, Characterization and In vitro Cytotoxicity of 5-Fluorouracil Loaded Polymeric Electrospun Nanofibers for the Treatment of Skin Cancer

2019 ◽  
Vol 13 (2) ◽  
pp. 114-128 ◽  
Author(s):  
Gayatri Patel ◽  
Bindu K.N. Yadav
Keyword(s):  
Skin Cancer ◽  
Basal Cell Carcinoma ◽  
Cell Viability ◽  
Cell Carcinoma ◽  
Basal Cell ◽  
Fiber Diameter ◽  
Electrospun Nanofibers ◽  
In Vitro Cytotoxicity ◽  
Fractional Factorial

Background: The purpose of this study was to formulate, characterize and conduct in vitro cytotoxicity of 5-fluorouracil loaded polymeric electrospun nanofibers for the treatment of skin cancer. The patents on electrospun nanofibers (US9393216B2), (US14146252), (WO2015003155A1) etc. helped in the selection of polymers and method for the preparation of nanofibers. Methods: In the present study, the fabrication of nanofibers was done using a blend of chitosan with polyvinyl alcohol and processed using the electrospinning technique. 5-fluorouracil with known chemotherapeutic potential in the treatment of skin cancer was used as a drug carrier. 24-1 fractional factorial screening design was employed to study the effect of independent variables like the concentration of the polymeric solution, applied voltage (kV), distance (cm), flow rate (ml / hr) on dependent variables like % entrapment efficiency and fiber diameter. Results: Scanning electron microscopy was used to characterize fiber diameter and morphology. Results showed that the fiber diameter of all batches was found in the range of 100-200 nm. The optimized batch results showed the fiber diameter of 162.7 nm with uniform fibers. The tensile strength obtained was 190±37 Mpa. Further in vitro and ex vivo drug release profile suggested a controlled release mechanism for an extended period of 24 hr. The 5-fluorouracil loaded electrospun nanofibers were found to decrease cell viability up to ≥50% over 24 hr, with the number of cells dropping by ~ 10% over 48 hr. As the cell viability was affected by the release of 5-fluorouracil, we believe that electrospun nanofibers are a promising drug delivery system for the treatment of Basal Cell Carcinoma (BCC) skin cancer. Conclusion: These results demonstrate the possibility of delivering 5-Fluorouracil loaded electrospun nanofiber to skin with enhanced encapsulation efficiency indicating the effectiveness of the formulation for the treatment of basal cell carcinoma type of skin cancer.

scholarly journals Optimization of Electrospun Poly(caprolactone) Fiber Diameter for Vascular Scaffolds to Maximize Smooth Muscle Cell Infiltration and Phenotype Modulation

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 643 ◽  
Author(s):  
Dae Geun Han ◽  
Chi Bum Ahn ◽  
Ji-Hyun Lee ◽  
Yongsung Hwang ◽  
Joo Hyun Kim ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Fiber Diameter ◽  
Electrospun Fiber ◽  
Electrospun Nanofibers ◽  
Macrophage Infiltration ◽  
Vsmc Proliferation ◽  
Vascular Scaffolds ◽  
Poly Caprolactone

Due to the morphological resemblance between the electrospun nanofibers and extracellular matrix (ECM), electrospun fibers have been widely used to fabricate scaffolds for tissue regeneration. Relationships between scaffold morphologies and cells are cell type dependent. In this study, we sought to determine an optimum electrospun fiber diameter for human vascular smooth muscle cell (VSMC) regeneration in vascular scaffolds. Scaffolds were produced using poly(caprolactone) (PCL) electrospun fiber diameters of 0.5, 0.7, 1, 2, 2.5, 5, 7 or 10 μm, and VSMC survivals, proliferations, infiltrations, and phenotypes were recorded after culturing cells on these scaffolds for one, four, seven, or 10 days. VSMC phenotypes and macrophage infiltrations into scaffolds were evaluated by implanting scaffolds subcutaneously in a mouse for seven, 14, or 28 days. We found that human VSMC survival was not dependent on the electrospun fiber diameter. In summary, increasing fiber diameter reduced VSMC proliferation, increased VSMC infiltration and increased macrophage infiltration and activation. Our results indicate that electrospun PCL fiber diameters of 7 or 10 µm are optimum in terms of VSMC infiltration and macrophage infiltration and activation, albeit at the expense of VSMC proliferation.

The J. C. Richardson Lecture: Prospects for Canadian Medical Neurology

1975 ◽  
Vol 2 (2) ◽  
pp. 101-107 ◽  
Author(s):  
D.W. Baxter
Keyword(s):  
Clinical Investigation ◽  
Postgraduate Education ◽  
High Standard ◽  
Undergraduate Curriculum ◽  
Influential Factors ◽  
Work Patterns ◽  
Consultation Service ◽  
The Past ◽  
Fundamental Research

In 1975, medical neurology is a well established, viable, growing specialty in Canada. There are now almost 250 neurologists scattered across the country, congregated largely in the hospitals associated with our 16 medical schools. Neurology is a major component of the undergraduate curriculum in each of these schools, and the majority of schools are approved for postgraduate training in our specialty. The Royal College has certified an average of 18 new neurologists each year for the past five years. In our hospitals we work closely with our internist and neurosurgical colleagues and we receive the support of highly competent teams of neuropathologists, clinical electrophysiologists and neuroradiologists. We believe that we provide a generally high standard of consultation service to our medical and surgical colleagues. We accept direct responsibility for patients suffering from a host of acute neurological problems, but we accept long term responsibility for very few. We do a great deal of teaching at both the undergraduate and graduate levels. In fact, the major role which neurology plays in undergraduate curricula, and the stimulus of postgraduate education, probably have been the two most influential factors shaping the number, work patterns and distribution of Canadian neurologists. Many of us are engaged in clinical investigation, but relatively few medical neurologists in Canada make fundamental research contributions.

Technique to Measure Adhesive Forces Between Electrospun Nanofibers

2009 ◽  
Vol 1240 ◽  
Author(s):  
Qiang Shi ◽  
Kai-Tak Wan ◽  
Shing-Chung Wong ◽  
Pei Chen ◽  
Todd A. Blackledge
Keyword(s):  
Unit Area ◽  
Fiber Diameter ◽  
Electrospun Nanofibers ◽  
Amorphous Region ◽  
Adhesive Force ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Ultrafine Fibers ◽  
Dry Adhesion ◽  
Adhesive Forces

AbstractDue to the difficulty in handling nanofibers, little is reported and understood on the dry adhesion between electrospun nanofibers. In this study, we develop a technique to measure the dry adhesive forces between electrospun nanofibers. Of critical importance is the ability to mimic naturally occurring dry adhesion such as that between gecko's and spider's foot hairs and untreated surfaces. The adhesion test was performed on two poly(e-caprolactone) electrospun ultrafine fibers using a nanoforce tensile tester. It was found that the adhesive force per unit area increased with decreasing fiber diameter. The degree of crystallinity, order parameters of macromolecules in the amorphous region and crystallite orientation of the spun fibers were determined by the differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD). The high measured adhesion between single PCL fibers in comparison to other reported values was attributed to crystal orientation due to electrospinning and the increase of adhesive force per unit area with decreasing fiber diameter.

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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