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EN
In this study, bioactive fibres were produced using polyvinyl alcohol (PVA), gelatin, polyvinyl pyrrolidone (PVP) as a polymer matrix, and different amounts of folic acid (FA) as a vitamin using the electrospinning technique. Loading of the folic acid in the polymers was determined by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR); morphologies and average diameters were analysed by Scanning Electron Microscopy (SEM), and Thermal Gravimetric Analysis (TGA) was applied to determine thermal behaviours. The FTIR spectra and TGA thermograms showed the successful incorporation of folic acid into the fibres. SEM images showed that various smooth and heterogenous electrospun fibres were produced with average diameters ranging from 125 to 980 nm. An in-vitro study was carried out using dissolved FA in an artificial sweat solution (acidic media, pH 5.44), and UV-Vis analysis of electrospun fibres was made. The in vitro release study showed that the FA loaded nanofibres had initial vitamin burst release behaviour. The maximum vitamin release percentage of the PVA/FA, gelatin/FA, and PVP/FA fibres was obtained as 86.88%, 80.2%, and 76.66%, respectively. From these results, we can state that FA-loaded fibres can be potential candidates for transdermal patches and topical applications.
PL
Wyprodukowano elektroprzędzione bioaktywne włókna, do których wytworzenia użyto polialkoholu winylowego (PVA), żelatyny, poliwinylopirolidonu (PVP) jako matrycy polimerowej oraz różnych ilości kwasu foliowego (FA) jako witaminy. Obecność kwasu foliowegow w polimerach określono metodą spektroskopii w podczerwieni z osłabionym całkowitym odbiciem i transformacją Fouriera (ATR-FTIR); morfologię i średnie średnice analizowano za pomocą skaningowej mikroskopii elektronowej (SEM), a do określenia zachowań termicznych zastosowano analizę termograwimetryczną (TGA). Widma FTIR i termogramy TGA wykazały udane włączenie kwasu foliowego do włókien. Obrazy SEM pokazały, że wytworzono gładkie i heterogeniczne włókna elektroprzędzone o średnich średnicach w zakresie od 125 do 980 nm. Przeprowadzono badanie in vitro z użyciem rozpuszczonego FA w roztworze sztucznego potu (środowisko kwaśne, pH 5,44) oraz wykonano analizę UV-Vis włókien elektroprzędzonych. Badanie uwalniania in vitro wykazało, że nanowłókna obciążone FA wykazywały początkowo gwałtowne uwalnianie witamin. Maksymalny procent uwalniania witamin z włókien PVA/FA, żelatyna/FA i PVP/FA wyniósł odpowiednio 86,88%, 80,2% i 76,66%. Na podstawie tych wyników stwierdzono, że włókna obciążone FA mogą być potencjalnymi kandydatami do stosowania plastrów przezskórnych i zastosowań miejscowych.
2
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.
EN
The graphene-like two dimensional (2D) inorganic materials have been been shown great interest for a variety of applications. In this work, polymer composite nanofibres containing molybdenum disulfide (MoS2) nanosheets were obtained by electrospinning. The MoS2 nanosheets were well dispersed inside the fibres, and the nanofibres maintained the fibre morphology well with the MoS2 nanosheets embedded. The incorporation of MoS2 nanosheets changes polymer nanofibre morphology from round to ribbon-like. Moreover, through thermogravimetric (TG) analysis and dynamic mechanical thermal analysis (DMTA) measurements, it was found that the MoS2 nanosheets as an additive material led to an increase in thermal stability and in the storage modulus. This work comprises an extensive approach to producing a novel 2D inorganic-organic composite structure, which should be applicable for membrane engineering with enhanced thermal and mechanical stability.
PL
Dwuwymiarowe nieorganiczne materiały podobne do grafenu wywołały liczne zainteresowanie w różnych zastosowaniach. W pracy otrzymano metodą elektroprzędzenia kompozytowe nanowłókna polimerowe zawierające disiarczek molibdenu (MoS2). Nanoskładniki MoS2 były dobrze rozproszone we włóknach, a ich morfologia była na zadowalającym poziomie. Włączenie nanoskładników MoS2 zmienia nanowłókna polimerowe z morfologii okrągłej na wstążkową. Co więcej, dzięki analizie termograwimetrycznej (TG) i pomiarom dynamicznej mechanicznej analizy termicznej (DMTA) stwierdzono, że dodatek MoS2 może zapewnić wzrost stabilności termicznej i zwiększyć moduł przechowywania. Praca prezentuje rozszerzone podejście do produkcji nowej dwuwymiarowo nieorganiczno-organicznej struktury kompozytowej, która może mieć zastosowanie w wytwarzaniu membran o podwyższonej stabilności termicznej i mechanicznej.
EN
Electrospun materials are good candidates for the design of tissue regeneration scaffolds as they can simulate the natural surroundings of tissue cells. The study proposes electrospun polycaprolactone (PCL)/cefuroxime (CFU) scaffolds for human cell culture and investigates the influence of the antibiotic content on scaffold morphology, thermal and mechanical properties. The increase in the CFU concentration resulted in the reduction of fiber diameter and number of deformations. It also influenced the reduction of scaffold thermal enthalpies and improved scaffold break strength. With regard to cell growth, the scaffolds showed precedence in greater colonization of the HeLa cells. Finally, these scaffolds showed compatibility with standard human cell lines, and thus they can be used for the repair of damaged tissues.
EN
Polyvinylidene fluoride (PVDF) fibrous membranes with fiber diameter from nanoscale to microscale were prepared by electrospinning. The structural parameters of PVDF fibrous membrane in terms of fiber diameter, pore size and its distribution, porosity or packing density, thickness, and areal weight were tested. The relationship between solution concentration and structural parameters of fibrous membrane was analyzed. The filtration performance of PVDF fibrous membrane in terms of air permeability and filtration efficiency was evaluated. The results demonstrated that the higher solution concentration led to a larger fiber diameter and higher areal weight of fibrous membrane. However, no regular change was found in thickness, porosity, or pore size of fibrous membrane under different solution concentrations. The air permeability and filtration efficiency of fibrous membrane had positive correlations with pore size. The experimental results of filtration efficiency were compared with the predicted values from current theoretical models based on single fiber filtration efficiency. However, the predicted values did not have a good agreement with experimental results since the fiber diameter was in nanoscale and the ratio of particle size to fiber diameter was much larger than the value that the theoretical model requires.
EN
Nanofibers were electrospun from bicomponent poly(vinyl alcohol) (PVA) and modified cationic starch (CS) mixed solution PVA/CS with different mass ratios (75/25, 50/50 and 35/65) at a total concentration of 12 wt% for all polymer compositions. For comparison, pure PVA solution was used. Electrospinning technique Nanospider (Elmarco, Czech Republic) with a rotating electrode with tines was used to obtain nanofibrous web. The influence of prepared polymer solution compositions on the structure and morphology of nanofibers and webs were investigated. Analyzing the structure and morphology of the formed nanofiber webs, it was noticed that the fineness nanofibers were formed from the PVA/CS solution with a mass ratio of 50/50. This ratio of solution also lets us to obtain the nanofibrous web with less sticked nanofibers on spunbond. The increase in the CS ratio by more than 50/50 had a negative influence on the diameter of nanofibers and the structure of nanofibrous web.
8
Content available remote Electrospinning of Chitosan Biopolymer and Polyethylene Oxide Blends
EN
The objective of this study is to investigate the morphological (scanning electron microscopicy images), thermal (differential scanning calorimetry), and electrical (conductivity) properties and to carry out compositional analysis (Fourier-transform infrared) of produced nonwoven fibrous materials adapted in biomedical applications as scaffolds. The orientation of produced nanofilaments was also investigated because it is considered as one of the essential features of a perfect tissue scaffold. Viscosity and electrical conductivity of solutions, used in the manufacturing process, were also disassembled because these properties highly influence the morphological properties of produced nanofibers. The nanofibrous scaffolds were fabricated via conventional electrospinning technique from biopolymer, synthetic polymer, and their blends. The chitosan (CS) was chosen as biopolymer and polyethylene oxide (PEO) of low molecular weight as synthetic polymer. Solutions from pure CS were unspinnable: beads instead of nanofibers were formed via spinning. The fabrication of pure PEO nanomats from solutions of 10 wt%, 15 wt%, and 20 wt% concentrations (in distilled water) turned out to be successful. The blending of composed CS solutions with PEO ones in ratios of 1:1 optimized the parameters of electrospinning process and provided the opportunity to fabricate CS/PEO blends nanofibers. The concentration of acetic acid (AA) used to dissolve CS finely spuninned the nanofibers from blended solutions and influenced the rate of crystallization of manufactured fiber mats. The concentration of PEO in solutions as well as viscosity of solutions also influenced the diameter and orientation of formed nanofibers. The beadless, highly oriented, and defect-free nanofibers from CS/PEO solutions with the highest concentration of PEO were successfully electrospinned. By varying the concentrations of AA and low molecular weight PEO, it is possible to fabricate beadless and highly oriented nanofiber scaffolds, which freely can found a place in medical applications.
9
Content available remote Fabrication of polymeric micro-tube components - recent developments
EN
For numerous technical sectors, the achievements in past decades in manufacturing of micro-components enabled to develop new generations of products with reduced mass and volume as well as with an increasing number of functions integrated in an ever-smaller space. This continuing trend of miniaturization includes an increasing demand for polymeric tubular micro-parts applied for example in medical devices, micro-fluidic and thermal management systems. Recent research in the fabrication of polymeric micro-tube products is therefore dealing with manufacturing techniques for high-volume production, developing new processes such as micro-blow moulding or hot embossing. Similarly, measures for an increased functionalization of polymeric micro-tubes were part of investigations for medical purposes and artificial neural networks were applied to model extrusion processes. The objective of this article is to provide a structured overview about the recent advances in fabricating polymeric micro-tube components with a particular focus on the achievements in innovative shaping techniques.
DE
Die Entwicklungen im Bereich der Fertigung von Mikrobauteilen in den vergangen zwei Jahrzehnte eröffnen heute zahlreichen Industriebereichen neue Möglichkeiten für innovative Produkte mit einer zunehmend höheren Funktionsdichte bei immer kleiner werdendem Bauraum und Gewicht. Dieser anhaltende Trend zur Miniaturisierung ist auch im zunehmenden Bedarf rohrförmiger Mikrobauteile aus Kunststoffen erkennbar, beispielsweise für Anwendungen in der Medizintechnik, der Mikrofluidik oder für Wärmetauschersysteme. Aktuelle Forschungsarbeiten befassen sich daher mit Fertigungsmethoden zur Herstellung rohrförmiger Mikrokomponenten in großen Stückzahlen, wie zum Beispiel dem Mikroblasformen oder dem Heißprägen. Für Anwendungen in der Medizintechnik wurden darüber hinaus verschiedene Maßnahmen zur Schaffung erhöhter Funktionalitäten kunststoffbasierter rohrförmiger Mikrobauteile untersucht. Künstliche neuronale Netze wurden für die Abbildung von Extrusionsprozessen eingesetzt. Ziel des vorliegenden Beitrages ist es, eine strukturierte Übersicht über aktuelle Entwicklungen in der Herstellung rohrförmiger Mikrobauteile aus Kunststoffen zu geben mit einem besonderen Schwerpunkt auf innovative Techniken zur Formgebung.
EN
Novel poly(vinyl alcohol) (PVA) andchitosan (CS) or 2-hydroxyethyl methacrylate (HEMA) and nanohydroxyapatite(nanoHAp) electrospinning-produced membranes were evaluated, in terms of theirbioactivity under exposure to simulated body fluid (SBF). After soaking them inSBF for 5, 8 and 15 days, the scanning electron microscopy (SEM) images showthe accumulation of calcium carbonate or calcium phosphate SBF on the surfaceof the nanohydroxyapatite (nanoHAp). This indicates that there might be anincreased bioactivity on the surface of the nanoHAp prepared by this method.
PL
Zbadano bioaktywność nowych membran, otrzymywanych w wyniku elektroprzędzenia z hydrożeli poli(alkoholu winylowego) (PVA) z chitozanem (CS), metakrylanem 2-hydroksyetylu (HEMA) i/lub nanohydroksyapatytem (nanoHAp), poddanych działaniu symulowanego płynu ustrojowego (SBF). Metodą skaningowej mikroskopii elektronowej (SEM) stwierdzono, że po zanurzeniu wytworzonych membran w roztworze SBF na 5, 8 i 15dni na powierzchni cząstek nanoHAp w badanych próbkach nastąpiła akumulacja cząsteczek węglanów i fosforanów wapnia pochodzących z SBF, co dowodzi, że tą metodą można zwiększyć bioaktywność przygotowanych membran, przeznaczonych do zastosowania w rekonstrukcji tkanki kostnej.
EN
Electrospinning can be used to create nanofiber mats from diverse polymers which can be used as filters etc. Depending on the spinning parameters, also nano-membranes, i.e. non-fibrous mats, can be produced as well as mixtures from both morphologies. The ratio of membrane to fibrous areas can be tailored by the distance between the high voltage electrode and substrate. Here the impact of the mat morphology on the water vapour permeability through polyacrylonitrile nanofiber mats with different membrane-like areas is shown, allowing for tailoring the permeability between 0.1 Pa m²/W and more than 10 Pa m²/W. In this way it is possible to create the finest filters as well as nearly impenetrable thin membranes with the same technology.
PL
Elektroprzędzenie można stosować do tworzenia mat z nanowłókien z różnorodnych polimerów, które mogą być stosowane jako filtry itp. W zależności od parametrów przędzenia, można wytwarzać także nanobłonki, tj. maty niewłókniste, jak również ich hybrydy. Stosunek powierzchni membrany do części włóknistej może być regulowany przez odległość między elektrodą wysokiego napięcia a podłożem. W pracy pokazano wpływ morfologii maty na przepuszczalność pary wodnej poprzez poliakrylonitrylowe maty z nanowłókien z obszarami membranopodobnymi, pozwalając dostosować przepuszczalność między 0,1 Pa·m²/W i ponad 10 Pa·m²/W. Dzięki temu sposobowi możliwe jest tworzenie najlepszych filtrów, a także prawie nieprzeniknionych cienkich membran z zastosowaniem tej samej technologii.
EN
In this study, after the synthesis of zinc cyclohexane mono carboxylate, its chemical structure was analysed with FTIR and TGA. Then electrospun polyvinylpyrrolidone nanofibres containing zinc cyclohexane mono carboxylate were produced and antibacterial properties of the nanowebs obtained were investigated for their use in the textile field. When the FTIR results of the nanofibres containing different concentrations of zinc cyclohexane monocarbocylate are examined, an –OH peak similar to that of PVP fibres is noticed. These results clearly indicate that zinc cyclohexane monocarboxylate is included in PVP. When the TGA spectra of CHMCZn doped nanofibres at different ratios are examined, it is seen that they give more similar results than polyvinylprolidone nanofibres alone. According to the SEM-EDX analyses, it was observed that the fibre diameters obtained were in the range of 145-947 nm. On the other hand, antimicrobial activity against B. subtilis, S. aureus and E. coli strains was detected, regardless of the CHMCZn concentration.
PL
W pracy analizowano za pomocą FTIR i TGA strukturę chemiczną syntetyzowanego monokarboksylanu cykloheksanu cynku. Następnie metodą elekroprzędzenia wytworzono nanowłókna poliwinylopirolidonowe zawierające monokarboksylan cynkowo-cykloheksanowy i zbadano właściwości antybakteryjne otrzymanych włókien pod kątem ich zastosowania w branży tekstylnej. Podczas badania wyników FTIR nanowłókien zawierających różne stężenia monokarbocylanu cynkowo-cykloheksanowego zauważono pik -OH podobny do występującego w przypadku włókien PVP. Te wyniki wyraźnie wskazują, że monokarboksylan cykloheksanu cynku jest zawarty w PVP. Wykonano badania widm TGA nanowłókien domieszkowanych CHMCZn w różnych proporcjach. Po wykonaniu analiz SEM-EDX zaobserwowano, że otrzymane średnice włókien mieściły się w zakresie 145–947 nm. Ponadto wykryto aktywność przeciwdrobnoustrojową przeciwko szczepom B. subtilis, S. aureus i E. coli, niezależnie od stężenia CHMCZn.
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.
14
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 study, photochromic spirooxazine material of N-methyl-3,3-dimethyl-9'-hydroxy-spiro[2H-indole-2-[3H] naphtho [2,1-b] [1,4] oxazine] was synthesised. Spirooxazine/PVDF fiber (SPF) membranes with different contents ofspirooxazine were successfully prepared by electrospinning. The SPF membranes were characterised by FTIR and SEM.The photochromic properties and contact angle of the SPF membranes were evaluated. The results show that the SPF membranes change from colorless to blue whenexposed to UV light, but they revert to their original colour after the UV light disappears. The colour difference and contact angle of the SPF membranes firstly increase and then decrease with a rise in the content of spirooxazine.
PL
W pracy otrzymano fotochromowy materiał spirooksazynowy N-metylo-3,3-dimetylo-9'-hydroksy-spiro [2H-indolo-2 - [3H] nafto [2,1-b] [1,4] oksazyny]. Za pomocą elektroprzędzenia wytworzono membrany z spiroksaksyny i fluorku poliwalildanu PVDF (SPF) o różnej zawartości spiroksaksyny. Błony SPF scharakteryzowano za pomocą FTIR i SEM. Oceniono właściwości fotochromowe i kąt zwilżania błon SPF. Wyniki pokazały, że membrany SPF zmieniają kolor z bezbarwnego na niebieski po ekspozycji na światło UV, ale powracają do swojego pierwotnego koloru po zaniku światła UV. Różnica barwy i kąt zwilżania membran SPF najpierw wzrastają, a następnie zmniejszają się wraz ze wzrostem zawartości spirooksazyny.
EN
Direct conversion of nanofibers into a yarn formed by electrospinning has begun to draw attention recently while pioneering attempts in fact go back to 1930s. Once nanofiber yarns are spun successfully by electrospinning, obviously, this would open new gates for many different applications. However, this is still a challenging task and there is no system accepted universally yet. There are more than 20 different approaches available so far but with serious limitations. In this review, they were categorized as (i) systems for production of parallel bundle of nanofibers and (ii) systems for production of twisted nanofiber yarns, presenting potential applicability of each with a critical point of view. The results show that some of the attempts mainly present basic conceptual ideas only. There are some works to produce real twisted nanofiber yarns continuously while mainly funnel, disc, or ring collectors have been used as the twisting element. However, there is limited information regarding stability of spinning system or control of yarn properties. This review also analyses the technical properties of electrospun nanofiber yarns summarizing the available data in terms of yarn properties such as fiber fineness, twist, production speed, mechanical properties, polymer types, and other important parameters available.
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.
18
EN
In this study, a simple, general and straightforward method for growing metal-organic frameworks (MOFs) crystals directly on nanofibers is presented. A chelating polymer was first blent with metal cation and then electrospun. The obtained nanofibers were immersed in a linker solution. Metal cations were released and the metal-organic frameworks crystals were grown on the fibers’ surface. In this work, this method was tested with polyvinyl alcohol as chelating polymer, Zn2+ as metal cation and Terephthalic acid as linker. The pair cation/linker corresponds to the MOF-5. The latter is a robust metal organic framework formed from Zn4O nodes with 1,4-benzodicarboxylic acid struts between the nodes. SEM images revealed that the MOF-5 nanocrystals have grown along the PVA/Zn2+ nanofibers that served as the crystals’ growth template by providing the Zn2+ ions. This result was also confirmed by infrared spectroscopy, which indicates the presence of characteristic bands of MOF-5 in the modified nanofibers spectrum. Moreover, the X-ray diffraction showed that MOF-5 material was well crystallized on the nanofibers surface according to a cubic symmetry with a space group Fm-3m and a lattice constant a = 25.8849 Å.
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
Smart clothes can be described as textiles that change their behavior under some external factors (stimulants). The response of the smart cloth can be passive (just as a sensor) or active (where a combination of sensing and another reaction takes place). The materials involved in these textiles are crucial for many applications, especially for health related applications where the “wearables” can provide instantaneous monitoring and aid to people with certain disabilities. This work consists of two main parts: First it investigates the different materials used in smart clothing for monitoring the vital activities of the human body (e.g. the breathing rates) with an emphasis on piezoresistive structures as they work sensing elements for mechanical strains. Second this work presents the production of functional membrane samples based on synthesized pyrrolinone ester hydrazone dye with a preliminary investigation of their chemical and geometrical parameters, especially their sensitivity for monitoring the presence of ammonia to function as a smart textile based colorimetric chemosensor.
PL
„Inteligentne” ubrania można opisać jako tekstylia, które reagują pod wpływem czynników zewnętrznych (bodźców). Odpowiedź „inteligentnej” odzieży może być bierna (czujnik) lub czynna (wykrywanie i reakcja). Materiały związane z tymi wyrobami tekstylnymi mają kluczowe znaczenie dla wielu zastosowań, zwłaszcza dla tych związanych ze zdrowiem, gdzie odzież może zapewnić natychmiastowy monitoring i pomoc osobom niepełnosprawnym. Przedstawiona praca składała się z dwóch głównych części: najpierw badano różne materiały stosowane w „inteligentnej” odzieży do monitorowania istotnych czynności organizmu ludzkiego (np. szybkości oddychania), ze szczególnym uwzględnieniem struktur piezorezystancyjnych. W drugiej części pracy przedstawiono wytwarzanie funkcjonalnych membran z zastosowaniem syntetycznego barwnika, zbadano parametry chemiczne i geometryczne, w szczególności wrażliwości na monitorowanie obecności amoniaku w celu zastosowania wyrobu jako chemosensor kolorymetryczny.
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