Mathematical modelling of the electrospinning process for production of polyvinyl alcohol nanofibers (original) (raw)
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Optimising the electrospinning process conditions to produce polyvinyl alcohol nanofibres
International Journal of Nanotechnology, 2009
Polyvinyl alcohol (PVA) is a semi-crystalline, hydrophilic polymer with reasonable physical and mechanical properties which has broadly practical applications. Ultra fine PVA fibres which have potential applications in filtration and biomedical engineering could be produced by electrospinning. In this work the process conditions to produce PVA nanofibres were optimised and the effects of various variables such as electric voltage, tip to target distance, flow rate and solution parameters on the morphology of nanofibres were investigated. The mechanical properties of fibre mats such as Young's modulus and tensile strength were also evaluated. The results showed that the fibre diameter and morphology were significantly affected by these parameters. The fibre diameter was in the range of 300-500 nm which is decreased with increasing the tip to target distance and electric voltage. It is also reduced with lessening flow rate and solution concentration.
Effects of Electrospinning Voltage and Flow Rate on Morphology of Poly-vinyl Alcohol Nanofibers
Journal of Physics: Conference Series, 2019
Nanofibers have obtained considerable interest for use in various applications. Polyvinyl alcohol (PVA) has been used to achieve many benefits for diverse pharmaceutical and biomedical applications. We investigated in this study the effects of applied voltage, needle diameter, and flow rate on morphologies of PVA nanofibers. A constant volume of the feeding solutions delivered to the needle at a flow rate of 1and 2 mL/h with high potentials of voltage was applied as they exit the needle. After that, the electrospun fibers collected on the ground connected aluminum foil. The electrical conductivity measurements of feeding solutions performed at room temperature. Characterization of the PVA nanofibers conducted using scanning electron microscopy (SEM) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The obtained nanofibers SEM images show beads when using the flow rate at 1 mL/h, whereas increasing the voltage and the flow rate improved the morphology of the nanofibers to uniform without beads. The FTIR results show that O-H and CO bands are the main attributing to the chemical functionality of PVA nanofibers. As a conclusion, the high voltage and flow rate considered as the most critical parameters that impacted on PVA nanofibers morphology.
Effect of Molecular Weight on the Morphology of Electrospun Poly ( Vinyl Alcohol ) Nanofibers
2014
Morphological characteristics of electrospun PVA nanofibers were investigated in terms of polymer molecular weight was reported in this paper. The change in the morphology depending on the polymer concentration of electrospinning solution and the applied voltage were addressed. The fiber diameter increased with the increase in the molecular weight and polymer concentration and applied voltage and the average nanofiber diameter variation was found to be between 175.83 and 735.69 nm.
Journal of Applied Polymer Science, 2009
Poly(vinyl alcohol) (PVOH) was obtained from the alkaline hydrolysis of poly(vinyl acetate) (PVAc). Nonwoven membranes (mats) of PVOH nanofibers were produced by electrospinning of solutions of PVOH in water with and without aluminum chloride. The concentration of the PVOH/water solution was 12.4% w/v. The morphology of the mats was analyzed by scanning electron microscopy (SEM). The thermal properties and the degree of crystallinity of the nanofibers were measured by differential scanning calorimetry (DSC); the crystal structure of the mats was evaluated by wide-angle X-ray diffraction. The best nanofibers were obtained by electrospinning the PVOH/water solution with aluminum chloride (45% w/v) in which an electrical field of 3.0 kV/cm was applied. It was observed that the addition of the aluminum chloride and the increase in the applied electrical field decreased the number-average nanofibers diameters. The mats without aluminum chloride had higher melting temperatures and higher degrees of crystallinity than the mats with the salt. The crystal structure of the mats was found to be monoclinic; however, the mats were neither highly oriented nor have a high degree of crystallinity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
2014
Polymer nanofibers exhibit properties that make them a favorable material for the development of tissue engineering scaffolds, filtration devices, sensors, and high strength lightweight materials. Electrospinning is a versatile method commonly used to manufacture polymer nanofibers. Collection of electrospun nanofibers across two parallel plates is a technique useful for creating nanofiber structures because it allows for the collection of linearly oriented individual nanofiber arrays and these arrays can be easily transferred to other substrates or structures. It is of importance to have some understanding of the capabilities of this collection method, such as the maximum length of fibers that can be collected across two parallel plates. The effect of different electrospinning parameters on maximum fiber length, average fiber diameter, diameter uniformity, and fiber quality was explored. It was shown that relatively long continuous polycaprolactone (PCL) nanofibers with average diameters from approximately 350 nm to 1 µm could be collected across parallel plates at lengths up to 35-50 cm. Experimental results lead to the hypothesis that even longer continuous nanofibers over 50 cm could be collected if the size of the parallel plates were increased. Extending the maximum fiber length that can be collected across parallel plates could expand the applications of electrospinning. Polymer solution concentration, plate size, and applied voltage were all shown to have varying effects on maximum fiber length, fiber diameter, and fiber uniformity.
Modeling and optimization of electrospinning of polyvinyl alcohol (PVA)
Advances in Polymer Technology, 2017
The electrospun fibers can have applications in diverse fields, such as tissue scaffolds, optical electronics, nanocatalysis, and sound absorption. Nanoscale fibers with a higher surface area can provide superior mechanical, physical, and thermal properties. Therefore, investigation of the factors affecting the electrospinning process, for various materials, is required. In this study, the design of experiments issued for optimization of electrospinning of polyvinyl alcohol (PVA). Analysis of variance (ANOVA) and the Taguchi orthogonal array L27OA are employed to analyze the influence of process control parameters. The variables studied are the applied voltages, solution concentrations, rotational speeds, collecting distances, and flow rates. A mathematical model of the polymer fiber diameter as a function of significant process parameters has been built using response surface methodology (RSM). The concentration percentage and the flow rate were determined to be the most significant process variables at 99% and 90% confidence levels, respectively. The predictive model provides 84.34% average model accuracy, which is considered acceptable as this study deals only with 27 of 243 trials needed for a full study based on principles of design of experiments. An additional ANOVA test and corresponding mathematical model have been developed to obtain the interaction effects for processing parameters. K E Y W O R D S design of experiments, electrospinning, polyvinyl alcohol nanofibers, response surface methodology 1 | INTRODUCTION Electrospinning has received continued attention in the last two decades because of its versatility in fabricating a wide variety of polymeric fibers and its effectiveness in producing fibers in the submicron range. [1] Electrospun fibrous mats have numerous applications, such as nanocatalysis, tissue scaffolds, protective clothing, optical electronics, filtration, personal care, composite, insulation, energy storage, and sound absorption. [2-5] These fibers have several advantageous characteristics such as large surface area to the volume ratio, flexibility in the surface functionalities, and superior mechanical performance (e.g., stiffness and tensile strength).
Applied Mechanics and Materials, 2010
The present work was aimed at studying the effects of process parameters on morphologies of Polyvinyl alcohol (PVA) nanofibers in a novel electrospinning technique, bubble electrospinning. The process was optimized by constructing L 9(3 4 ) orthogonal experimental array design. Three factors were investigated and nine tests were run under lower, medium and higher levels of these factors. The results showed that PVA solution concentration plays an important role in affecting the morphologies of PVA nanofibers in bubble electrospinning process. With the increase of the concentration of PVA solution, the morphologies of fibers were changed from beaded fibers to uniform cylinder fibers and the average nanofiber diameter also increased. The optimization process was 12w% for PVA solution, 30kV for applied voltage and 10cm for spinning distance.
On the electrospinning of poly(vinyl alcohol) nanofiber mats: A revisit
Journal of Applied Polymer Science, 2008
Electrospinning was used to fabricate mats of poly(vinyl alcohol) (PVA; M w 5 72,000 Da, degree of hydrolysis 97.5-99.5) nanofibers from PVA solutions in reverse osmotic water. The effects of solution concentration, applied electrical potential, sonication, and collection distance on morphological appearance and diameters of the as-spun fiber mats as well as those of the individual fibers were carefully investigated mainly by scanning electron microscopy. The effect of the distance from the center of the as-spun fiber mat on morphological appearance and diameters of the as-spun fibers was also investigated. The mechanical integrity of some as-spun PVA fiber mats was also investigated. At all concentrations and applied electrical potentials investigated, the average diameters of the as-spun PVA fibers ranged between 85 and 647 nm. The use of sonication to prepare a PVA solution caused the viscosity of the solution to decrease; hence, the observed decrease in the average diameters of the as-spun fibers and the average diameters of the asspun fibers were practically the same throughout the asspun fiber mat.
Preparation and Characterization of the PVA Nanofibers produced by Electrospinning
Madridge Journal of Nanotechnology & Nanoscience
Electrospinning is a simple and quick technique for producing fibers with nanoscale diameters from a wide range of materials. The Polyvinylalcohol PVA Polymer dissolved in the DMF was electrospun to obtain the alignment nanofibers PVA. The nanofibers were obtained using 25 wt% solution concentration, an applied voltage 10 kV, spinning distance10 cm and different flow rates of 0.1, 0.2, and 0.3 ml/hr. The properties of alignment nanofibres including morphology, crystallization, functional group and the effect of flow rates on it was studied. The morphology of the electrospun PVA nanofibres is studied using scanning electron microscopy (SEM). Structural characteristics analysis by X-ray diffraction (XRD) that showed the crystalline peaks of the PVA nanofibers. The formation of functional groups of PVA polymer was predicted by the FT-IR spectra
THE INFLUENCE OF ELECTROSPINNING PROCESS PARAMETERS ON THE MORPHOLOGY OF THE PVP NANOFIBERS
The article describes the investigation of the effect of electrospinning process parameters wherein the distance between the electrodes was variable, the voltage and the flow rate of the polymer solution was constant for the obtained polymer nanofibers from the solution of PVP/EtOH with concentration of 10% by weight. The morphology of produced nanofibers was examined using a scanning electron microscope (SEM). Based on the SEM images a series of measurements of the nanofibers diameters for each sample were executed and then the results were averaged. The research shows that reducing the distance between the electrodes has a significant impact on the diameter of the PVP nanofibers.