Effect of organic solvents in morphology and mechanical properties of electrospun polyvinylpyrrolidone fibers (original) (raw)
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Research Article, 2020
Due to its properties such as biocompatibility, water solubility and stability, polyvinylpyrrolidone (PVP) becomes more and more attractive for biomedical applications. This polymeric material is used in various applications such as pharmaceutical aid, complexing agent or solubilizer. PVP nanofibers are often produced using PVP solutions in solvents with high toxicity such as dimethylformamide (DMF). The aim of this study is to investigate the effect of process parameters on the electrospinning behavior of polyvinylpyrrolidone in solvents with lower toxicity such as dimethylsulfoxide (DMSO) or ethanol. Therefore, solutions of PVP in ethanol, PVP in DMSO or PVP in binary solvent systems such as DMSO/ethanol or DMSO/acetone were prepared and electrospun. The effect of process parameters such as voltage, flow rate, tip-to-collector distance were examined. A solution parameter, the polymer concentration was also considered. The morphology and diameter of the electrospun nanofibers were characterized by scanning electron microscopy (SEM). The effect of the solution viscosity was also questioned. Nanofibers with a homogeneous cylindrical morphology were obtained in the case of PVP in ethanol solutions for a polymer concentration of 7 wt.%. The process parameters were: a voltage of 15kV, tip-tocollector distance of 15 cm and a flow rate of 1.25 mL/h. PVP in DMSO solutions didn't allow the obtention of solid nanofibers on the collector where a wetness zone appears. This shows that the solvent could not evaporate quickly. A wetness was also observed with PVP solutions prepared using binary solvent systems where a more volatile solvent such as ethanol or acetone was used.
Materials Today: Proceedings, 2018
Electrospinning is a systematic process of elaborating nanofibers by forcing a polymer fluid through a spinneret by the application of electric field. Polyvinylpyrrolidone (PVP) is a hydrophilic polymer that has good film formation properties.PVP thin films are widely used as a sensitive layer in Surface Acoustic Wave (SAW) sensors in order to detect the volatile organic compounds.The present study was aimed at development of cost effective electrospinning system for production of quality thin films and parametric optimization. Experimental investigation was performed by electrospinning of PVP considering 7.5wt %, 10wt %,12.5wt %,15wt %,dissolved in Di-MethylFormamide (DMF). The process parameters considered were voltage of 20kV, flow rate 0.5ml/hr, needle dimension 21 gauge and tip-to-collector distance 100 mm. It was found that concentration of polymer is a critical factor in controlling the beads formation and fiber diameters although applied voltage and tip-to-collector distance also influenced the fiber diameter.With increase in concentration of the polymer solution the formation of beads formation reduced significantly with increase in fiber diameter. The fiber diameter varied between 25.50 nm to 113.84 nm. Minimum fiber diameter obtained was 25.5 nm whereas the corresponding bead diameter was 647.39 nm for 10 wt % polymer concentration. Maximum fibre diameter obtained was for 15 wt % polymer concentration with 135.85 nm and the corresponding bead diameter of 1208.35 nm. Morphological studies of electrospun thin films by Scanning Electron Microscope (SEM) revealed the formation of fibres in nano dimension, PVP with 10 wt % dissolved in DMF and suitable process parameters can result in nanofibres with lesser bead formation.
Fabrication of Polyvinylpyrrolidone Nanofibers with Green Solvents
Süleyman Demirel Üniversitesi Fen Edebiyat Fakültesi Fen Dergisi, 2019
In this study, biocompatible Polyvinylpyrrolidone (PVP) nanofibers were produced with ultra-pure water, rose water, lavender water, ethanol, acetone and acetic acid with green electrospinning approach. Polymer solutions were characterized with conductivity, surface tension and viscosity measurements. Morphological analyzes were carried out with Scanning Electron Microscope (SEM). Conductivity, surface tension and viscosity results of PVP/ ultra-pure water, rose water and lavender water solutions were similar. On the other hand, PVP/acetic acid solution has the highest viscosity and lowest conductivity values and PVP/ethanol solution has got the lowest surface tension. In addition; the lowest average fiber diameters were obtained from ultra-pure water, rose water and lavender water solvents but there are some beads on the nanofiber structure. The smoothest nanofibers without beads were obtained from PVP/ethanol but it was observed that average fiber diameter is about 724 nm higher th...
Journal of Achievements in Materials and Manufacturing Engineering, 2016
Purpose: The aim of this study was to produce poly(vinylpyrrolidone) (PVP) containingsilica nanofibers using electrospinning method from 10% PVP/EtOH solutions with differentmass concentration 0 and 30% of tetraethoxysilane. Sol-gel technique was used to obtainnanofiber membranes with high amount of inorganic phase. In the case when metal alkoxide,such as tetraethyl orthosilicate (TEOS) is mixed with an organic polymer, hydrolysis andcondensation reaction of TEOS occur in-situ with polymer matrix, which allows to fabricateorganic-inorganic hybrid structures with uniform dispersion.Design/methodology/approach: The examination of the morphology of the obtainedPVP/silicon dioxide nanofibers using scanning electron microscope (SEM) has been made.The chemical structure of produced nanostructures was investigated by Fourier - TransformInfrared spectroscopy (FTIR) and Energy Dispersive Spectrometry (EDX) to analyze theregular dispersion by examining types of bonds occurring between polymer...
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 solvents on electrospun polymeric fibers: preliminary study on polystyrene
Polymer International, 2004
Six solvents (acetic acid, acetonitrile, m-cresol, toluene, tetrahydrofuran (THF) and dimethylformamide (DMF)) with different properties (eg density, boiling point, solubility parameter, dipole moment and dielectric constant) were used to prepare electrospun polystyrene (PS) fibers. Fiber diameters were found to decrease with increasing density and boiling point of the solvents. A large difference between the solubility parameters of PS and the
Size dependent mechanical properties of electrospun polymer fibers from a composite structure
Polymer
The elastic modulus of individual electrospun polyvinyl-alcohol (PVA) fibers was measured using atomic force microscopy (AFM) based bending tests. Results indicated an increase in the elastic modulus as the fiber diameter decreased. Consideration of electrospun fibers as a composite structure consisting of a shell region of aligned polymer chains surrounding a bulk-like isotropic core was analytically modeled and showed good agreement with the experimental data. Phase contrast AFM imaging of focused ion beam (FIB) prepared PVA fiber cross-sections provided a method of observing the shell–core structure directly and supported the model proposed. These findings indicate the potential for considerable polymer chain alignment for the production of high performance fibers using electrospinning methods.
Towards Analysis and Optimization of Electrospun PVP (Polyvinylpyrrolidone) Nanofibers
Advances in Polymer Technology
In this study, the polymeric nanofibers of polyvinylpyrrolidone (PVP) were manufactured using the electrospinning technique. The electrospinning process parameters such as voltage, polymer concentration, rotational speed of the collecting drum, collecting distance, and flow rate were optimized to obtain the minimum fiber diameter for sound absorption applications. The effects of these parameters on the fiber diameter as output responses were investigated by analysis of variance (ANOVA) and Taguchi’s array design. Furthermore, a mathematical model was generated using response surface methodology (RSM) to model the electrospinning process. The high voltage and polymer concentration were observed to be the most significant parameters at 95% and 99% confidence level. The average model accuracy of 83.4% was observed for the predictive model of electrospinning which is considered acceptable as it is composed of complete experimental trials of 27 out of 243 runs. The experimental study off...
2016
Polystyrene (PS) dissolved in a mixture of N, N-dimethylformamide (DMF) and/or tetrahydrofuran (THF) was electrospun to prepare fibers with sub-micron diameters. The effects of electrospinning parameters, including solvent combinations, polymer concentrations, applied voltage on fiber morphology, as well as tensile and hydrophobic properties of the fiber mats were investigated. Scanning electron microscope (SEM) images of electrospun fibers (23% w/v PS solution with applied voltage of 15 kV) showed that a new type of fiber with double-strand morphology was formed when the mass ratio of DMF and THF was 50/50 and 25/75. The tensile strength of the PS fiber film was 1.5 MPa, indicating strong reinforcement from double-strand fibers. Bead-free fibers were obtained by electrospinning 40% (w/v) PS/DMF solution at an applied voltage of 15 kV. Notably, when the ratio of DMF and THF was 100/0, the maximum contact angle (CA) value of the electrospun PS films produced at 15 kV was 148°.
Effect of Solvent and Distance Tip-Collector on PEO Fibers Electrospinning
International Symposium "Technical Textiles - Present and Future", 2022
In this study, polyethylene oxide (PEO) fibers were produced through the versatile electrospinning technique. In electrospinning, a polymer solution is dispensed from a needle tip of a syringe where an intense electric field attracts the solution to a collector while drawing the polymer into a very thin fiber. High resolution scanning electron microscopy SEM was used to assess the influence of solvent as well as distance from tip to collector at a constant applied voltage on fiber morphology and diameter. Polyethylene oxide powder with average molecular weight of 900 kD was dissolved in a solvent mixture constituting deionized, distilled water and ethanol in different weight ratio (1:5, 3:2 and 5:1). The 4% (w/v) polymer solutions were electrospun at tip-collector distance which was varied between 15 and 25 cm. The effect of solvent mixture and tip-collector distance on the fiber diameter was investigated by using statistical analysis. This revealed a liniar dependency between solution, process parameters and fiber diameter. Once the tip to collector distance was increased, the fiber diameter decreased and bead-free fibers were obtained. Also, it was found from the results that nanofibers with an average diameter of 216 nm were obtained at a ratio 3:2 in solvent mixture.