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EN
Peripheral nerve damages take place as a result of trauma, compression, or disease, resulting in sensory loss, impaired motor function, and subsequent challenges. In the current study, ginkgo biloba extract was loaded into PCL/gelatin scaffolds through electrospinning method. The scaffolds were characterized in vitro using various studies. The prepared nanofibrous scaffolds were rolled up to make neural guidance channels. Then, the conduits were seeded with adipose derived stem cells and transplanted into a rat model of sciatic nerve injury. The scaffolds were not toxic and had optimal tensile and suturability. The animals treated with the conduits that delivered adipose derived stem cells and ginkgo biloba extract and received the treadmill exercise had significantly higher motor and sensory functions recovery. In addition, histopathological examinations showed beneficial role of the exercise plan on the nervous system repair.
EN
Black TiO2 nanofibers have recently emerged as a promising material that has both advantages of black metal oxide and one-dimensional nanostructure. However, current reduction-based synthesis approaches are not compatible with practical applications because these processes require high process costs, complicated processes, and sophisticated control. Therefore, it is still necessary to develop a simple and facile method that can easily introduce atomic defects during the synthesis process. This work suggests an electrospinning process with an antioxidant and subsequent calcination process for the facile synthesis of black TiO2 nanofibers. The synthesized black TiO2 nanofiber has an average diameter of 50.3 nm and a rutile structure. Moreover, this nanofiber represented a noticeable black color and a bandgap of 2.67 eV, clearly demonstrating the bandgap narrowing by the introduced atomic defects.
EN
The growing interest in one-dimensional tin oxide-based nanomaterials boosts research on both high-quality nanomaterials as well as production methods. This is due to the fact that they present unique electrical and optical properties that enable their application in various (opto)electronic devices. Thus, the aim of the paper was to produce ceramic SnO₂ nanowires using electrospinning with the calcination method, and to investigate the influence of the calcination temperature on the morphology, structure and optical properties of the obtained material. A scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR) were used to examine the morphology and chemical structure of obtained nanomaterials. The optical properties of manufactured one-dimensional nanostructures were investigated using UV-Vis spectroscopy. Moreover, based on the UV-Vis spectra, the energy band gap of the prepared nanowires was determined. The analysis of the morphology of the obtained nanowires showed that both the concentration of the precursor in the spinning solution and the calcination temperature have a significant impact on the diameter of the nanowires and, consequently, on their optical properties.
PL
Nanowłókna polimerowe wzbudzają obecnie ogromne zainteresowanie ze względu na ich potencjalne wykorzystanie w różnych procesach technologicznych, np. w produkcji tkanin lub wytwarzaniu membran. Włókna te wykazują wyjątkowe właściwości, takie jak: duży stosunek powierzchni do objętości oraz duża porowatość. Znanych jest kilka metod wytwarzania nanowłókien, jednak ze względu na prostotę, powtarzalność i niewielkie koszty, najpowszechniej stosowane jest przędzenie elektrostatyczne. Przedstawiono przegląd najnowszych osiągnięć w zakresie zastosowań nanowłókien polimerowych w medycynie, obejmujący zagadnienia materiałów opatrunkowych, uwalniania substancji aktywnych oraz inżynierii tkankowej.
EN
Polymer nanofibers are currently of great interest in terms of their potential use in various technological processes, e.g. in the manufacture of textiles or membranes. These fibers are characterized by extraordinary properties such as high surface to volume ratio and high porosity. There are several methods of manufacturing nanofibers, but for reasons of simplicity, repeatability and low cost, electrostatic spinning is the most common. The article presents a review of the latest developments in the application of polymer nanofibers in medicine, including such issues as bandage materials, release of active substances and tissue engineering.
EN
Cylindrical-electrode-assisted solution blowing spinning (CSBS) is a novel nanofiber preparation method. The electric field of CSBS not only is one of the main innovations of this technology but also plays a key role in the preparation of nanofibers. In this article, the electric field of CSBS and the influences of electric field on the preparation of nanofibers were studied systematically for the first time by simulations, theoretical analyses, and experiments. This paper innovatively established the coaxial capacitor model for studying the CSBS electric field. The effects of electric field on the preparation and morphology of CSBS nanofibers were theoretically investigated by using this model. The theoretical formulas that can express the relationships between the various electric field variables were obtained. The electric field strength distribution, voltage distribution, and the relationships between the electric field parameters of CSBS were obtained by finite element simulations. The simulations’ results show that reducing the diameter of cylinder (DC) or increasing the voltage increase the electric field strength of the jet surface. Experimental results reveal that increasing voltage or reducing DC can reduce the diameter of nanofibers. The experimental and simulation results prove the correctness of the theoretical research conclusions. The theoretical and simulation conclusions of this paper lay a theoretical foundation for further study of CSBS electric field. The experimental conclusions can directly guide the controllable preparation of CSBS nanofibers.
EN
The dynamic development of the world economy entails an increasing exchange of goods and population. This means that we are globally struggling with increasing levels of nosocomial infections. The increasing use of antimicrobial agents triggers the microorganisms’ immune system, which in turn contributes to the increasing amount of antibiotic-resistant microorganisms, making it necessary to control the development of unwanted microorganisms, including bacteria, especially those carried on the body and clothing. Currently, there is no unique method to combat the multiplication of microorganisms and eliminate threats to human health and life. For this reason, this article describes the possibilities of using graphene materials as a potential additive materials in fiber finishes as an antibacterial aspect in various areas of life. However, the literature does not explain the mechanisms behind the antibacterial properties of graphene, strongly limiting its textile application. The research is conducted using molecular dynamic simulations of interaction between graphene materials and murein. The obtained results suggest the electrostatic mechanism of blocking the growth and division of bacteria. Due to the physical interaction, bacterial cell becomes “trapped” without changing its growth parameters. This may lead to an increase of internal cell pressure, rupture of its wall and consequently its death.
EN
The aim of this work was to produce a thin SnO2 film by a technique combining the sol-gel method and electrospinning from a solution based on polyvinylpyrrolidone and a tin chloride pentahydrate as a precursor. The spinning solution was subjected to an electrospinning process, and then the obtained nanofiber mats were calcined for 10 h at 500°C. Then, the scanning electron microscopy morphology analysis and chemical composition analysis by X-ray microanalysis of the manufactured thin film was performed. It was shown that an amorphous-crystalline layer formed by the SnO2 nanofiber network was obtained. Based on the UV-Vis spectrum, the width of the energy gap of the obtained layer was determined.
EN
Electrospinning is a technique used to manufacture nano- and submicron fibers based on synthetic or natural polymers. Additionally, biomaterials used in the electrospinning procedure can be modified by bioactive compounds, e.g. peptides or growth factors. The microstructure of the obtained fibrous scaffolds mimics natural extracellular matrix (ECM) environment. The size and the microstructure of the fibrous scaffolds are considered to be suitable for cells adhesion and proliferation. Various design features of the electrospinning device (e.g. the shape of the collector, the shape of the nozzle, the direction of the applied voltage) or electrospinning conditions (e.g. humidity, temperature) allows to control properties of the fibers (their shape, diameter, porosity). Novel structures, such as core-shell fibers, porous fibers attracted wide attention due to their properties and functionalities. Porous fibers or fibers with nanoscaled structures can be obtained in several ways. These methods are mainly focused on using high humidity and highly volatile solvent applied in the electrospinning process. The core-shell structure can be obtained by coaxial electrospinning. That binary fiber has ability to control the release rate of drug enclosed within the shell or core. The drug release profile can be also modified by loading the pharmacological agent either directly to the spinning solution or its post immobilization.This diversity of the electrospun fibers is a reason for non-woven materials to be considered for application as drug carriers. The review of electrospinning methods presented here proves that the control over fibers surface area, morphology and the choice of polymer enable modelling of drug release kinetics.
EN
Constantly developing nanotechnology provides the possibility of manufacturing nanostructured composites with a polymer matrix doped with ceramic nanoparticles, including ZnO. A specific feature of polymers, i.e. ceramic composite materials, is an amelioration in physical properties for polymer matrix and reinforcement. The aim of the paper was to produce thin fibrous composite mats, reinforced with ZnO nanoparticles and a polyvinylpyrrolidone (PVP) matrix obtained by means of the electrospinning process and then examining the influence of the strength of the reinforcement on the morphology and optical properties of the composite nanofibers. The morphology and structure of the fibrous mats was examined by a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS) and Fourier-transform infrared spectroscopy (FTIR). UV –Vis spectroscopy allowed to examine the impact of zinc oxide on the optical properties of PVP/ZnO nanofibers and to investigate the width of the energy gap.
PL
Przedstawiono właściwości nanowłókien, metody ich wytwarzania oraz obszary zastosowania. Zaprezentowano oraz przeanalizowano parametry charakteryzujące materiały filtracyjne z dodatkiem nanowłókien. Opracowano metodykę badań charakterystyki aerodynamicznej oraz charakterystyki: skuteczności, dokładności i oporu przepływu wkładów filtracyjnych z dodatkiem nanowłókien w zależności od współczynnika chłonności pyłu km. Przedstawiono charakterystyczne parametry filtracyjne materiałów z dodatkiem nanowłókien. Wykonano pięć wkładów różniących się materiałem filtracyjnym z dodatkiem nanowłókien oraz bez tej warstwy. Opracowano warunki badań oraz przygotowano stanowisko badawcze. Przeprowadzono badania charakterystyk aerodynamicznych wykonanych wkładów filtracyjnych oraz charakterystyk skuteczności i dokładności filtracji i oporów przepływu wkładu standardowego (celulozowego), a także z dodatkiem nanowłókien. Potwierdzono pozytywny wpływ warstwy nanowłókien na wzrost skuteczności i dokładności filtracji powietrza wlotowego do silnika. Dokonano oceny składu granulometrycznego pyłu w powietrzu za standardowym wkładem filtracyjnym i wkładem z dodatkiem nanowłókien.
EN
Nanofiber properties, methods of their production, and areas of their application have been presented. Parameters describing filtration materials with nanofibers addition were presented, and analyzed. Methodology for testing aerodynamic characteristics as well as characteristics of: efficiency, accuracy, and filter cartridges resistance with nanofibers addition, depending on the dust mass loading km were developed. Characteristic filtration parameters of the materials with nanofibers addition are presented. Five filtration inserts, differing in the filtration material with nanofibers addition, and without this layer were made. Test conditions were developed as well as a test stand was prepared. Aerodynamic characteristics tests of filter cartridges as well as filtration efficiency, accuracy, and flow resistance of standard (cellulose) cartridge, and the ones with nanofibers addition were performed. The positive effect of nanofiber layer on efficiency, and accuracy increase in the inlet engine air filtration was confirmed. Granulometric composition of air dust was assessed on a standard filter cartridge, and on a cartridge with nanofibers addition.
EN
Neodymium-Iron-Boron (Nd-Fe-B) magnets are considered to have the highest energy density, and their applications include electric motors, generators, hard disc drives, and MRI. It is well known that a fiber structure with a high aspect ratio and the large specific surface area has the potential to overcome the limitations, such as inhomogeneous structures and the difficulty in alignment of easy axis, associated with such magnets obtained by conventional methods. I n this work, a suitable heat-treatment procedure based on single-step and multistep treatments to synthesize sound electrospun Nd-Fe-B-O nanofibers of Φ572 nm was investigated. The single-step heat-treated (directly heat-treated at 800°C for 2 h in air) samples disintegrated along with the residual organic compounds, whereas the multistep heat-treated (sequential three-step heat-treated including three steps;: dehydration (250°C for 30 min in an inert atmosphere), debinding (650°C for 30 min in air), and calcination (800°C for 1 h in air)) fibers maintained sound fibrous morphology without any organic impurities. They could maintain such fibrous morphologies during the dehydration and debinding steps because of the relatively low internal pressures of water vapor and polymer, respectively. In addition, the NdFeO3 alloying phase was dominant in the multistep heat-treated fibers due to the removal of barriers to mass transfer in the interparticles.
EN
Purpose: The aim of this study was to produce poly(vinylpyrrolidone) (PVP) containing silica nanofibers using electrospinning method from 10% PVP/EtOH solutions with different mass concentration 0 and 30% of tetraethoxysilane. Sol-gel technique was used to obtain nanofiber 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 and condensation reaction of TEOS occur in-situ with polymer matrix, which allows to fabricate organic-inorganic hybrid structures with uniform dispersion. Design/methodology/approach: The examination of the morphology of the obtained PVP/silicon dioxide nanofibers using scanning electron microscope (SEM) has been made. The chemical structure of produced nanostructures was investigated by Fourier - Transform Infrared spectroscopy (FTIR) and Energy Dispersive Spectrometry (EDX) to analyze the regular dispersion by examining types of bonds occurring between polymer matrix and SiO2 phase. Findings: Results obtained in this paper shows that the mass concentration of the reinforcing phase in form of TEOS have an influence on the average diameter of nanofibers and with the increase of tetraethyl orthosilicate in solution nanofibers diameters decrease. Moreover, structural examination shows uniform dispersion of the reinforcing phase in hybrid materials. Research limitations/implications: Uniform dispersion of the reinforcing phase in silica-containing PVP nanofibers gives the opportunity to make nanowires in calcination process from such obtained fibrous mats and use in novel electrical devices. Originality/value: This paper describes an easy and more effective way of making polymer nanofibers with the content of silicon dioxide with the perspective way of making silica nanowires in the future from obtained hybrid nanofibers, so that this method can replace commonly used nanowires growth processes.
EN
Purpose: Traditional nanofibers are weak in mechanical strength and also they lack in functional capacity to some extent for some of high performance applications. In this paper, in the light of these facts, development of plasma treated nanofibers having novel morphologies was reported. In other words, the surface of the nanofibers was treated using corona plasma instrument to differentiate fiber morphology so that they gain potential functional capabilities. To answer the question whether dramatic changes into nanofibrous architecture could be possibly obtained, the experiments were designed and carried out at different plasma and electrospinning process parameters such as different concentration of polymers solutions and bombardment of different power range and density to assess their consequences. SEM investigations and camera shots revealed that plasma treatment have provided unique structural changes even at low frequencies due to large surface area to volume ratio of nanofibers. The effect of plasma treatment on nanofibers alignment and morphology resulted in formation of duple and triple agglomerated nanofibers and a dramatic decrease in fiber diameters. Treated nanofibers might have switchable liquid absorption properties as well as specific air permeability that could be potentially used for functional applications. Findings: The experimental design and findings are unique in nanofibers literature in terms of application of standard plasma process and carbonization trials together as well as suggestion and introduction of a novel idea into development of a new apparatus in order to produce plasma treated nanofibers simultaneously. Practical implications: Practically, experimental results have also shown that, apart from application of plasma over nanofibers after electrospinning, it is expected that integration of electrospinning process and plasma process together will likely have better and longer lasting effects on fiber morphology. To this aim, a novel joint electrospinning/plasma apparatus could be designed with combination of a plasma box right after electrospinning area.
EN
Antimicrobial textile is a very important field for new investigations. The two aspects need be taken into account at the time of such investigations into the protection of the textile itself from damage caused by microorganisms, and that of the textile user against pathogenic or odour causing microorganisms. However, it is known that some materials which have really good antimicrobial activity are harmful or toxic and cannot be used for health care or medical application, due to which the necessity to find new natural and human friendly antimicrobial active materials and methods of how to increase the antimicrobial activity of textile is still open. One of the ways to solve this problem is usage of natural antimicrobial agents such as chitosan, plant extracts and others. Investigations on the usage of amber micro particles in the formation of a polyamide 6 nanoweb via electrospinning and on the antimicrobial activity thereof is analyzed in this paper. The results show the antimicrobial activity of the material with Baltic amber investigated and the possibility of developing functional antimicrobial textile with amber micro particles via electrospinning.
PL
Antymikrobowe tekstylia są bardzo ważnym przedmiotem nowych badań. Badając bierze się pod uwagę zarówno możliwości uszkodzenia samych tkanin przez mikroorganizmy, jak również działanie mikroorganizmów na użytkownika. Istotnym elementem, który należy brać pod uwagę jest to, że niektóre środki antymikrobowe są szkodliwe dla użytkownika dlatego poszukuje się nowych substancji antymikrobowych zwłaszcza pochodzenia naturalnego. W tym celu badano wpływ mikrocząstek bursztynu zawartych w runie z nanowłókien uzyskanych przez elektroprzędzenie. Wyniki okazały się obiecujące.
18
Content available remote Obtaining copper nanoparticles from nanocomposites of poly(vinyl alcohol) matrix
EN
Purpose: In this paper the development of technology for production of copper nanoparticles by thermal debinding matrix nanocomposite polymer nanofibers with reinforced of copper was reported. Electrospinning technique was used to synthesis composite nanofibers using a precursor composed of poly(vinyl alcohol) (PVA), copper acetate (CuAC) and acetic acid (C2H3OH). The resulting nanofiber was subjected to a high temperature in order to debinding of the organic part. The aim of this study was to attempt to obtain a one-dimensional nanostructured materials. Design/methodology/approach: The resulting nanostructures have been characterized using high resolution scanning electron microscopy (SEM). The influence of debinding conditions on one-dimensional nanostructured materials was observed. Research was execute on scanning electron microscope. Findings: On the basis of carried out researches the impact of the debinding of nanocomposite polymer nanofibers on the diameter of obtained nanostructures have been shown. The influence of debinding conditions on composite nanofibers were determined. Research limitations/implications: The research was carried out on technological variants, not on final elements. Originality/value: The paper presents attempt to obtain a one-dimensional nanostructured materials.
19
Content available remote Influence of inorganic additives on morphology of electrospun fibres
EN
Purpose: This paper describes the effect of inorganic additives and operating parameters of an electrospinning process on electrospun fiber diameters and morphology. Design/methodology/approach: Application of different solvents and process parameters impact characteristics of the micro and nanofibers made of PEO and also PVA with CuOAc. Findings: The results show that the three parameters (volumetric charge density, distance from nozzle to collector, and viscosity) have the most significant effect on the electrospun fiber morphology. The nano- and microfibers produced were characterized by scanning electron microscopy as well as with use of image analyzing tool DigitalMicrograph. Changes in length of stream and volatility of the solvent influence the shape of the fibres and internal solution load. The resulting fibre shape shows that for shorter distances the process was unstable, and the morphology of the filaments from a longer distance shows the gradual stabilization and indicates optimal process parameters. Practical implications: Based on the research carried out it is clear that micro and nanofiber characteristics vary widely depending on prepared solutions and process parameters. Originality/value: It was confirmed that inorganic additives, solvent type and process parameters have an effect on morphological aspects of produced micro and nanofibres.
EN
The influence of a carbon nanomaterials (CNM) obtained in a high-voltage discharge plasma on the endurance of elastomer compositions has been investigated. Complex tests of elastomeric compositions with highly dispersed carbon additives allowed us to confirm the model of nonlinear elastic deformation of macromolecules and adhesion between the elastomer and the nanoparticles. The results of these investigations agree with those obtained in determining the Mooney viscosity and relaxation, the parameters of the vulcanization kinetics of rubber mix, conventional tensile strength, relative breaking elongation of highly filled rubbers based on nitrile rubbers. To verify the assumed mechanism underlying the action of a carbon nanomaterial on elastomer compositions, the parameters of their vulcanizing network have been determined using the method of equilibrium swelling.
PL
Badano wpływ nanomateriału węglowego uzyskanego w plazmie z wyładowań wysokiego napięcia na trwałość kompozycji elastomerowych. Kompleksowe testy kompozytów elastomerowych zawierających dodatki węgla o dużym stopniu zdyspergowania pozwoliły na potwierdzenie modelu nieliniowego odkształcenia sprężystego makrocząsteczek oraz adhezji między między elastomerem i nanocząstkami. Wyniki tych badań zgadzają się z uzyskanymi wynikami badania lepkości Mooneya oraz relaksacji, parametrami kinetyki wulkanizacji mieszanki kauczukowej, konwencjonalnej, wytrzymałości na rozciąganie, wydłużenia przy zerwaniu wysoko napełnionych wulkanizatów opartych na kauczukach butadienowo-nitrylowych. W celu sprawdzenia założonego mechanizmu leżącego u podstaw działania nanomateriału węglowego w kompozycjach elastomerowych, parametry ich sieci wulkanizacyjnych zostały określone metodą spęcznienia równowagowego.
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