Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 75

Liczba wyników na stronie
first rewind previous Strona / 4 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  nanowłókna
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 4 next fast forward last
1
Content available remote Electrostatic fabrication of polymer nanofibers
EN
Fabrication process of nanofibers from the liquid polymer solution using electrospinning is described in the paper. In the experiments, polyvinylidene fluoride (PVDF) and dimethylformamide (DMF) were used as a polymeric material and a solvent, respectively. Additionally, the results of the measurements of diameters of obtained fibers, current-voltage characteristics of the process and calculation of resistivity of liquid polymer are presented.
PL
W pracy przedstawiono proces elektrostatycznego wytwarzania nanowłókien z roztworu ciekłego polimeru. W procesie elektroprzędzenia w roli polimeru i rozpuszczalnika użyto odpowiednio polifluorek winylidenu (PVDF) i dimetyloformamid (DMF). Dodatkowo badania obejmowały pomiary średnic otrzymanych włókien, charakterystyk prądowo-napięciowych procesu oraz wyznaczenie rezystywności ciekłego polimeru.
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.
3
Content available remote Innovations in poly(vinyl alcohol) derived nanomaterials
EN
Poly(vinyl alcohol) (PVA) has been considered as an important commercial synthetic thermoplastic polymer. PVA is a low cost, reasonably processable, optically transmitting, heat stable, and mechanically robust plastic. PVA-based nanomaterials usually comprise of the nanocomposites (PVA/graphene, PVA/carbon nanotube, PVA/nanodiamond, PVA/metal nanoparticle) and nanofibers. The structural, optical, mechanical, and electrical properties of the PVA-based nanomaterials have been enhanced with nanofiller addition or nanostructuring. This review offers fundamentals and advanced aspects of poly(vinyl alcohol) and the derived nanomaterials. It highlights recent advances in PVA nanocomposites and nanofibers for potential applications. The PVA-based nanomaterials have been successfully employed in fuel cells, sensors, batteries, membranes, electronics, and drug delivery relevances. The challenges and opportunities to strengthen the research fields of PVA-based nanomaterials have also been presented.
PL
Jednym z kierunków rozwoju technologii materiałowych jest nanotechnologia rozumiana jako dziedzina zajmująca się zastosowaniem nanododatków do wytwarzania nowych materiałów oraz ich wpływem na parametry modyfikowanych materiałów. W ostatnich latach nanotechnologia wkracza do technologii modyfikacji asfaltów stosowanych do wykonania nawierzchni drogowych. W artykule przedstawiono stosowane obecnie w budownictwie drogowym nanododatki oraz ich właściwości.
EN
One of the direction in the development of the material technology is nanotechnology, understood as using nanoadditives to create new materials and the impact of the additives on the properties of modified materials. In recent years nanotechnology is increasingly used in the modification of the bitumen used in the asphalt pavements. The article presents presently used nanoadditives and their properties.
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
Purpose: The article focuses on the production of polymer nanofibres from poly(lactic acid) using the electro-spinning method, i.e. the technique of forming fibres in an electrostatic field. The main aim of the publication was to analyse the influence of the distance between electrodes on the morphology of one-dimensional polymeric materials obtained. Design/methodology/approach: In the practical part of the study solutions of polylactide in acetone and a mixture of chloroform/dimethylformamide (DMF) were produced. After 72 hours of mixing, no homogeneous solutions were obtained, therefore a solution consisting of a polylactide dissolved in chloroform was prepared, to which dimethylformamide was added in order to dilute the mixture. The morphology of the nanostructures obtained was analysed by means of a scanning electron microscope (SEM) equipped with an X-ray energy dispersion spectrometer (EDS), which allowed to analyse the chemical composition of the nanofibres produced. The electro-spinning method used to obtain fibres is characterized by high versatility - it gives the possibility to produce fibres from a wide range of polymers. Electro-spinning is also an economic method, and spinned fibres have a wide application potential. Findings: Nanofibres obtained by electro-spinning from the previously produced solution, regardless of the distance between the nozzle and the collector (10 or 20 cm) did not show any significant discrepancies in the values of measured diameters. Fibres obtained at increased distance between electrodes (20 cm) are characterized by a smaller average diameter value, but the difference is small, fluctuating between 48-49 nm. In the case of the sample formed during electro-spinning at the distance of the nozzle - collector equal to 10 cm and the sample produced at the distance doubled, no defects in the structure of the obtained nanofibres were observed. The analysis of topographic images of surfaces produced in the course of nanostructures' work did not show any significant influence of the distance between the nozzle and collector on the diameter of fibres. No defects in the structure of one-dimensional polymer materials obtained allowed to state that the distance between the nozzle and the collector in the range of 10-20 cm is the optimal parameter of the electro-spinning process allowing to obtain smooth, untangled fibres. Practical implications: The fibrous polymer mats obtained during the electro-spinning process of polylactide can be used as protective clothing materials, as drug delivery systems, as tissue scaffolding and as filtration membranes. Originality/value: At present, there are few articles in the literature on the electrospinning process, due to the fact that it is a constantly developing matte for the production of nanofibres. Moreover, most of the research focuses on fibres obtained from nonbiodegradable polymers, which do not have the advantages of fibres obtained from polylactide.
EN
At electrspark alloying (ESA) of aluminum surfaces using Al-Sn tool-electrode (TE), nanostructuring of manufactured surfaces take place owing to the formation of SnO2 nanofibers. Examining the tribological properties of these surfaces in a friction couple with a counterbody made of hardened steel showed that the wear of counterbody during the friction in the oil and at dry friction exceeds by an order of magnitude and above it the wear of such surfaces.
9
Content available remote Electrospinning of PAN and composite PAN-GO nanofibres
EN
Purpose: The aim of this study was to present the influence of used reinforcement phase – graphene oxide (GO) and the electrospinning process parameters (the distance between the nozzle and collector) on the morphology and the structure of the obtained composite PAN-GO nanofibres. Design/methodology/approach: To produce pure polymer nanofibers, a 10% (wt.) electrospinning solution the polyacrylonitrile (PAN) was dissolved in N, N-dimethylformamide (DMF). The spinning solution used for electrospinning PAN-GO composite fibres was made by dissolving the PAN in a mixture of GO and DMF. By changing the configuration of the distance between the nozzle and collector (10 and 20 cm) and maintaining the remaining parameters (solution flow rate and potential difference between the electrodes), four samples in the form of nanofibrous mats were made. In order to identify the structure and morphology of the reinforcing phase, X-ray microanalysis (EDX) and scanning electron microscopy (SEM) were performed. In addition, the structure of graphene oxide microparticles was investigated by a Raman spectrometer. In order to determine the influence of the distance between the nozzle and the collector used in the electrospinning process and the addition of the reinforcing phase to the morphology and structure of the obtained PAN polymer nanofibres and PAN-GO composite nanofibres, they were examined using SEM. The analysis of the chemical composition of PAN and PAN-GO fibres was carried out using X-ray microanalysis. Findings: The morphology and structure analysis indicated that polymer nanofibres PAN for both the distances between the nozzle and the collector show no structural defects and presented same diameter over the entire length of the fibre. Nanofibres with the addition of GO obtained at both distances between the electrodes, showed defects in the form of beads. In addition, it was observed that with increasing distance between the nozzle and collector the diameter of obtained nanofibres is smaller for both pure PAN and composite PAN-GO samples. Research limitations/implications: The paper is the basis for further research in the field of the use of PAN-GO composite nanofibres as water purification materials. Originality/value: The electrospinning method can be an alternative to conventional methods for the production of filtering membranes due to the ease of carrying out the process and the fact that a material with a high specific surface area is obtained.
EN
In this article, we investigate the convective heat transfer of the two-dimensional unsteady squeezing flow past a Riga plate. To examine the heat transfer, Cattaneo-Christov heat flux model is used. Influence of entropy generation on heat transfer has been investigated numerically. With the help of suitable similarity transformation, the governing partial differential equations (PDEs) are converted into ordinary differential equations (ODEs). The obtained system of non-linear ordinary differential equations subject to the convective boundary conditions is solved by the shooting method using the computational software MATLAB. To strengthen the reliability of the results obtained by the shooting method, the MATLAB built-in function bvp4c has been used. The graphs show the effect of different physical parameters for velocity, temperature, concentration and tables are presented to observe the behaviour of skin friction and sherwood number under the influence of certain physical parameters. It is observed that for increasing values of thermal relaxation parameter, the temperature profile increases and an opposite behaviour is shown for the concentration profile. Moreover, with an increase in the Brinkman number, the entropy generation increases.
EN
The article presents an overview of electrospinning process development from the first investigations in the field of behaviour of liquids in an electrostatic field to the electrospinning methods and investigations in the 21st century. The article presents the history of electrospinning process development, the main problems that are solved, and also indicates the gaps in the field of standardisation of nanofibrous web structure measurement and estimation. There are a lot of works in which authors analyse influences of various parameters on the electrospinning process or on the structure of electrospun web, whereas the majority of them do not analyse the quality of structure using mathematical criteria. Such a situation leads to different conclusions and makes it impossible to compare various works by different authors. Despite numerous studies in electrospinning, investigations in the electrospun nanofibrous web estimation are not sufficient. Until now, a unique standard method for measuring and estimating the fibre diameter and web porosity has not been developed. The necessity of such a method and standards is obvious, and the lack of such a standard could have a negative influence on the electrospun product introduction into the market.
EN
Skin substitutes are heterogeneous group of scaffolds (natural or synthetic) and cells. We hypothesize that nanofibers with layer composition made of polylactide (PLA) and sodium hyaluronate (HA) obtained using electrospinning method are a good matrix for cell adhesion and proliferation. Methods: Optimal conditions of electrospinning of PLA and HA nanofibers to create layered compositions (PLA membrane covered with HA nonwovens) were determined by modifying parameters such as the appropriate amount of solvents, polymer concentration, mixing temperature and electrospinning process conditions. By changing the parameters, it was possible to control the diameter and properties of both polymer fibers. The spinning solution were characterized by surface tension and rheology. A scanning electron microscope (SEM) was used to determine the morphology and fiber diameters: PLA and HA. Structure of the PLA/HA nonwoven was analyzed using spectroscopy (FTIR/ATR). Biocompatibility of the nonwoven with fibroblasts (ECM producers) was assessed in the in vitro conditions. Results: The results showed that stable conditions for the formation of submicron PLA fibers were obtained using a 13% wt. solution of the polymer, dissolved in a 3:1 mixture of DCM:DMF at 45 °C. The hyaluronic fibers were prepared from a 12% wt. solution of the polymer dissolved in a 2:1 mixture of ammonia water and ethyl alcohol. All materials were biocompatible but to a different degree. Conclusions: The proposed laminate scaffold was characterized by a hydrophobic-hydrophilic domain surface with a maintained fiber size of both layers. The material positively underwent biocompatibility testing in contact with fibroblasts.
EN
Electrospinning is an effective technique for fabricating submicron to nanoscale fibers from synthetic polymer as well as natural proteins. In this study, multiwalled carbon nanotubes (MWNTs) were embedded via electrospinning by adding MWNTs into the spinning dope, and found to be well aligned along the fiber axis in the silk fibroin nanofibers. The morphology and microstructure of the electrospun nanofibers were characterised using a field emission scanning electron microscope (FESEM) and Transmission electron microscopy (TEM). X-ray diffraction (XRD) and TG-DTA were used to study the crystal structure of the silk/MWNTs composite nanofibres, carried out to alter the strength, toughness and electrical conductivity of silk nanofibers by adding a small amount of MWNTs. The electrospun random silk mats with 1% MWNTs had a Young’s modulus, ultimate tensile strength and strain of 107.46 ± 9.15MPa, 9.94 ± 1.2MPa and 9.25 ± 1.5%, respectively, and electrical conductivity increased to 1.2×10-4S/cm. The silk/MWNTs composite nanofibres could potentially be applied in nerve repair materials owing to their excellent mechanical properties and electrical conductivity.
PL
Za pomocą elektroprzędzenia wytworzono jedwabne nanowłókna z dodatkiem nanorurek węglowych. Zbadano wpływ nanorurek węglowych na morfologię, strukturę, właściwości mechaniczne i przewodność elektryczną j nanowłókien. Morfologię i mikrostrukturę otrzymanych nanowłókien scharakteryzowano za pomocą skaningowego mikroskopu elektronowego (FESEM) i transmisyjnej mikroskopii elektronowej (TEM). Wyniki badań rentgenowskich i cieplnych wykazały, że dodanie nanorurek nie wywierało istotnego wpływu na strukturę nanowłókien w porównaniu do niemodyfikowanych nanowłókien fibroinowych. Poprzez dodanie nanorurek uzyskano polepszenie właściwości mechanicznych, została również polepszona przewodność elektryczna nanowłókien. Na podstawie otrzymanych wyników stwierdzono, że jedwabne nanowłókna z dodatkiem nanorurek węglowych mogą być stosowane w materiałach do naprawy nerwów dzięki ich doskonałym właściwościom mechanicznym i przewodności elektrycznej.
EN
Polyacrylonitrile (PAN)/Co(OAc)2/carbon nanotubes (CNTs) composite nanofibers were fabricated via electrospinning with N,N-dimethylformamide (DMF) as solvent, and by carbonization and activation of the above precursor nanofibers, porous carbon composite nanofibers were successfully obtained. Scanning electron microscope, X-ray diffraction, ASAP 2020, and Solartron 1470 were used to characterize the surface morphology, the phase composition, specific surface area, and electrochemical property of the nanofibers, respectively. The result showed that some of the fibers were broken after sintering, and the surface area and pore volume of the porous C/Cu/CNTs were 771 m2/g and 0.347 cm3/g, respectively. The specific capacitance of the composite nanofibers reached up to 210 F/g at the current density of 1.0 A/g. Its energy density and power density were 3.1 Wh/Kg and 2,337 W/Kg, respectively, at the current of 0.5 and 5 mA.
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.
PL
Celem opisywanych badań była ocena wpływu cieczy jonowej należącej do grupy czwartorzędowych soli amoniowych, na właściwości biobójcze nanowłókien z polimeru PLA [poli(kwas mlekowy)] oraz PHB [poli(3-hydroksymaślan)]. Nanowłókna w postaci włókniny wytworzono za pomocą elektroprzędzenia z roztworu. Oba zaproponowane polimery termoplastyczne są nietoksyczne, biodegradowalne oraz biokompatybilne, ale nie wykazują aktywności biologicznej. Właściwość tę zaplanowano nadać nanowłóknom wykorzystując w tym celu ciecz jonową – azotan didecylodimetyloamoniowy [DDA][NO3], którą wprowadzono do roztworów poszczególnych polimerów przed procesem elektroprzędzenia. Przeanalizowano wpływ dodatku czwartorzędowej soli, zarówno na przebieg procesu elektroprzędzenia jak i na właściwości otrzymanych nanowłókien. Wykonano ocenę podatności otrzymanych nanowłókien na działanie grzybów pleśniowych poprzez ocenę stopnia wzrostu mikroorganizmów na badanych próbkach. Otrzymane nanowłókna poddano również ocenie mikroskopowej pod kątem ewentualnych zmian w strukturze włókien elementarnych z wykorzystaniem skaningowego mikroskopu elektronowego (SEM). Zbadano też parametry termiczne modyfikowanych nanowłókien, wyznaczając szybkość wydzielania ciepła w zależności od temperatury za pomocą mikrokalorymetru (PCFC), oraz oceniono możliwości zastosowania otrzymanych nanowłókien w procesie filtracji, wyznaczając parametry efektywności filtracji, spadku ciśnienia oraz współczynnik jakości otrzymanych filtrów.
EN
The aim of this study was to evaluate the effect of the ionic liquid belongs to quaternary ammonium salts on biocidal properties of PLA [poly(lactid acid)] and PHB [poly(3-hydroxybutyrate)] nanofibres. Nanofibres in non-woven form were prepared by electrospinning process. Both of these polyesters are non-toxic, biodegradable and biocompatible thermoplastics with high potential applications but they do not possess their own biological activity. The study was included the achievement of this activity by incorporating substances with antimicrobial properties. For this purpose the ionic liquid was selected. Didecyldimethylammonium nitrate [DDA][NO3] was added to the electrospinning solution of several polymers before electrospinning process. The influence of the quaternary salt addition on the course of electrospinning process and the nanofibres properties were observed. The evaluation of susceptibility of obtained nanofibres to mould fungi was made by assessing the degree of microbial growth on the samples surface. The morphology of the obtained nanofibres was characterized by scanning electron microscopy (SEM) to evaluate the nanofibre structure. The thermal parameters of modified nanofibers were also studied, setting the heat release rate depending on the temperature using microcalorimeter (PCFC). Also evaluated the applicability of the obtained nanofiber in the filtration process, setting the parameters of the filtration efficiency, pressure drop and the quality factor of the obtained filters.
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.
20
Content available remote Systemy uwalniania leków oparte na nanowłóknach
PL
W pracy podjęto się zadania stworzenia systemu uwalniania leków opartego na zastosowaniu biodegradowalnych materiałów polimerowych wytworzonych z nanowłókien otrzymywanych metodą elektroprzędzenia. Bezpośrednim celem tej pracy było stworzenie aktywnego opatrunku wspomagającego operacje neurochirurgiczne. Praca zawiera eksperymentalną i numeryczną analizę procesu uwalniania i transportu leku do typowego płynu buforowego oraz analogu tkanki mającą na celu znalezienie optymalnych warunków kontrolowania w czasie i przestrzeni rozkładu stężenia leku. Uwalnianie leku w zaproponowanym modelu matematycznym opisano za pomocą równań adsorpcji-desorpcji, zaś transport w porowatym materiale z wykorzystaniem równania dyfuzji. Przedstawiona analiza parametrów materiałów z nanowłókien mających wpływ na szybkość uwalniania leków, opis matematyczny procesu lokalnego uwalniania leków z materiałów polimerowych, jak również transportu substancji aktywnych w organizmie w szczególności w tkance mózgowej, pozwoliły na zbudowanie modelu numerycznego umożliwiającego parametryczną ocenę wpływu czynników geometrycznych, struktury materiału, metody enkapsulacji leku we włóknach, jak i własności nanowłókien na profile uwalniania leków. W rezultacie przeprowadzonych badań stworzono materiały do operacji chirurgicznych oparte na trzech lekach neuroprotektycznych: lipofilowego alfa-tokoferolu, oraz hydrofilowych czynników wzrostu NGF (Nerve Growth Factor) i BDNF (Brain Derived Neurotrophic Factor). Jako nośników leków użyto biodegradowalnych i biokompatybilnych polimerów poli(L-laktydu-co-kaprolaktonu) PLC, poli(L-laktydu) PLLA, poli(DL-laktydu-co-glikolidu) PDLG. Przeprowadzone we współpracy z Instytutem Medycyny Doświadczalnej i Klinicznej PAN operacje neurochirurgiczne wykonane na modelu zwierzęcym potwierdziły pozytywny wpływ wytworzonych z nanowłókien materiałów na proces regeneracji tkanki nerwowej, zapobiegając jednocześnie szkodliwemu dla tego procesu bliznowaceniu tkanki.
EN
In this work the task of preparation of drug release system based on the biodegradable polymeric materials made from nanofibers obtained by electrospinning is presented. The main goal of this work was to create an active dressing for the use in neurosurgery. The work includes experimental and numerical analysis of the release process and transport of the drug to the typical buffer fluid and tissue simulator aimed at finding the optimal conditions to control in time and space the drug concentration distribution. The drug release in proposed mathematical model was described by the adsorption-desorption equation while transport in the porous material by the diffusion equation. Presented analysis of nanofibrous material parameters affecting drug release rate, the mathematical description of the process of local drug release from polymeric materials as well as the transport of active substances in the body, in particular in brain tissue, enabled the construction of a numerical model allowing a parametric evaluation of geometric factors, structure of the material, the drug encapsulation in the fibers, as well as the properties of nanofibers on the drug release profiles. In order to calibrate and validate the numerical model, the experimental system have been proposed to assess transport of the drug analog (rhodamine B and the protein BSA) from the material located in a tissue simulating medium. As a result materials for surgical operations based on three neuroprotective drugs: lipophilic alpha-tocopherol and hydrophilic growth factors NGF (Nerve Growth Factor) and BDNF (Brain Derived Neurotrophic Factor) were developed. As a drug carriers biocompatible biodegradable polymers poly(L-lactideco-caprolactone) PLCL, poly(L-lactide) PLLA, poly(DL-lactide-co-glycolide) PDLG were used. Conducted in collaboration with the Mossakowski Medical Research Centre PAS neurosurgeries performed on an animal model confirmed positive impact of nanofibrous materials on the process of regeneration of nerve tissue, preventing at the same time improper process of tissue scarring.
first rewind previous Strona / 4 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.