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1

Regulation of N-type In2O3 Content on the Conductivity Typeof Co3O4 Based Acetone Sensor

Fu Lijuan, Fan Shuxing, Wang Zhao, Tang Wei

Materials Science Poland

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2023

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Vol. 41, No. 1

202--213

EN

A double-jet electrospinning method was adopted to fabricate In2O3/Co3O4 nanofibers (NFs). The sensitivity of In2O3/Co3O4NFs and In2O3NFs were compared and analyzed, and the morphology, structure, chemical composition, and gas-sensing properties of the samples were comprehensively characterized. The results show that the introduction of Co3O4can improve the response of In2O3/Co3O4to acetone, to 29.52 (In2O3/Co3O4) and 12.34 (In2O3) to 200 ppm acetone at 2000°C, respectively. In addition, the doping of Co3O4was found to reduce the optimum working temperature of pure In2O3 from 275°C to 200°C. The composite of Co3O4and In2O3not only enhances the sensing performance, but also leads to a conversion of p-n conductivity type. The phenomenon of the p-n transition is relevant to operating temperature and proportion of In2O3and Co3O4. While the enhanced acetone sensing properties of In2O3/Co3O4NFs may be attributed to the p-n hetero-junction between n-type In2O3 and p-type Co3O4 crystalline grains, which promotes the electron migration. The synergistic effects between In2O3and Co3O4and the large specific surface area of NFs additionally contribute to the improvements of acetone sensing performance.

2

Investigation of the Effect of Needle Diameter and the Solution Flow Rate on Fiber Morphology in the Electrospinning Method

Şimşek Gündüz Gonca

Fibres & Textiles in Eastern Europe

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2023

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Vol. 31, no. 4

22--29

EN

In the study, the morphological properties of polyacrylonitrile (PAN) fibers produced by electrospinning at different needle diameters and solution flow rates were investigated. For this purpose, 20G and 22G diameter needles were used. The fibres were produced at flow rates of 0.5 ml/hr, 1 ml/hr and 1.5 ml/hr. Scanning electron microscopy (SEM) was used to measure nanofiber diameters. Statistical analyzes were made with the help of the SPSS program. It was observed that finer fibers were obtained as the needle diameter decreased. As the solution flow rate increased, thicker fibers were obtained. In addition, it was observed that the needle diameter and flow rate affect the fiber arrangement and interfiber spacing.

3

Electrospun niobium oxide 1D nanostructures and their applications in textile industry wastewater treatment

Zaborowska Marta, Smok Weronika, Tański Tomasz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144941

EN

Textile industry emits daily huge amounts of sewage rich in non-biodegradable organic compounds, especially in textile dyes. Such contaminants are highly soluble in water, which makes their removal difficult. Other studies suggest their carcinogenicity, toxicity and mutagenicity. A promising chemical treatment of textile wastewater is the photodegradation of dye molecules in the process of photocatalysis in the presence of a photocatalyst. One-dimensional nanostructures exhibit a high surface-to-volume ratio and a quantum confinement effect, making them ideal candidates for nanophotocatalyst material. Nb2O5 is, among other metal oxides with a wide band gap, gaining popularity in optical applications, and electrospun niobium oxide nanostructures, despite their ease and low cost, can increase the chemical removal of textile dyes from wastewater. Facile synthesis of electrospun one-dimensional niobium oxide nanofibers is presented. The nanophotocatalysts morphology, structure, chemical bonds and optical properties were examined. Based on photodegradation of aqueous solutions (ph=6) of methylene blue and rhodamine B, the photocatalytic activity was established. The photocatalytic efficiency after 180 minutes of ultraviolet irradiation in the presence of Nb2O5 nanofibers was as follows: 84.9% and 31.8% for methylene blue and rhodamine B decolorization, respectively.

4

PAN-Based Carbon Fibers Deposition on NiTi Surface

Goryczka Tomasz, Szaraniec Barbara, Stodolak-Zych Ewa, Kluska Stanisława

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

1109--1114

EN

The main objective of the work was to create a layer of carbon nanofibre on the surface of the NiTi shape memory alloy. The coating process was carried out in three stages. First, polyacrylonitrile was deposited by electrospinning. Then it was stabilized at temperatures up to 250°C. The last stage was the carbonization performed below 1000°C. The microstructure of the obtained coatings was observed using a scanning electron microscope. The X-ray diffraction techniques were applied to analyze the coating structure. After the polyacrylonitrile deposition, the fibers had an average diameter of about 280 nm, and the final fibers were almost twice as tiny. The applied steps also changed the phase and crystalline state of the fibers, finally leading to the formation of amorphous-nanocrystalline graphite.

5

Adipose derived stem cells and ginkgo biloba extract-loaded PCL/gelatin nanofibrous scaffolds for peripheral nerve injury repair: The impact of physical activity

Gong Hua, Chen Zhengtian

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 4

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.

6

Production of pumice-containing nanofibers by electrospinning technique

Kılıçer Ali

Materials Science Poland

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2022

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Vol. 40, No. 2

206--213

EN

The scope of the study involves identifying the optimal means to effectively use the electrospinning technique to obtain pumice-containing nanofibers. Nanofiber containing pumice in a solution was electrospun to obtain smooth, cylindrical, bead-free, and ultrafine nanomaterials. The study also analyzed the molecular [Fourier transform infrared spectroscopy (FTIR)], thermal [differential scanning calorimetry (DSC)], zeta potential, size, polydispersity index [dynamic light scattering (DLS)], and surface [scanning electron microscope (SEM)] parameters of the pumice-containing nanofibers having JP6 (applied voltage: 6 kV) and JP12 (12 kV) properties. While the distance (10 cm), flow rate (0.8 mL/h), and other parameters of the electrospinning process were fixed, two different voltages were applied to obtain the pumice-containing nanofiber. The average diameter of the nanoencapsulated pumice produced at 6 kV was defined as 98.6 nm in gelatin nanomats with 31.8 nm. The average diameter of the nanocapsule pumice produced under a 12 kV voltage was found to be 85.8 nm, and the average diameter of the nanomats (non–nanoencapsulated) was 35.2 nm. The average zeta potential values of the pumice-containing nanofiber were also determined in the nanosize range. The JP6 and JP12 PDI values were determined as 0.165 and 0.566, respectively. Peaks characteristic of pumices as defined in the literature were observed in the FTIR results, while DSC analysis results revealed strong endo- and exothermic peaks. As a result of this study, it has been proved that pumice can be reduced to nanosize with the electrospinning technique and it is nanoencapsulated in nanofiber. When the obtained pumice-containing nanofiber was examined, it was determined that the surface area of the nanofiber was large and resistant to thermal heat.

7

Fabrication of heterojunction MnTiO3–TiO2-decorated carbon nanofibers via electrospinning as an effective multifunctional photocatalyst

Yousef Ayman

Materials Science Poland

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2022

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Vol. 40, No. 2

289--305

EN

In this paper, we successfully synthesized heterojunction manganese titanate/titanate nanoparticles (MnTiO3–TiO2 NPs)-decorated carbon nanofibers (CNFs) employing the electrospinning process. The morphology, crystallinity, and chemical composition of the MnTiO3–TiO2-decorated CNFs is characterized via SEM, FESEM, STEM, TEM EDX, and XRD techniques. The synthesized nanocomposite exhibits good performance for photodegradation of methylene blue (MB) dye and hydrolysis of ammonia–borane complex for hydrogen releasing experiment in a batch reactor under visible light. A mathematical model was developed to predict the photocatalytic activity of the produced nanocomposite with various parameters. The operational parameters include the effect of the initial concentration, catalyst dosage, light intensity, and reaction temperature, which are studied to validate the mathematical model. The reaction rate constant of MB photodegradation is found to be 0.0153 min−1 for an initial MB concentration of 5 mg·L−1 with a catalytic dosage of 200 mg·L−1 at a reaction temperature of 25°C under a light intensity of 25 W·m−2. Similarly, the H2 generation employing TiO2@CNFs and MnTiO3–TiO2@CNFs under visible light irradiation is observed to be 0.31 mol and 2.95 mol, respectively, corresponding to an exposure of 10 min. We also demonstrated that the yield of hydrogen employing MnTiO3–TiO2@CNFs under visible light increases to 2.95 mol compared with 1.51 mol in darkness. Finally, comparisons were made between the experimental and model-predicted values of the reaction rate constant and final concentrations. Theoretical and experimental data of photocatalytic activity are found to be in good agreement for MnTiO3–TiO2@CNFs.

8

Vascular stents - materials and manufacturing technologies

Malisz Klaudia, Świeczko-Żurek Beata

Engineering of Biomaterials

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2022

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vol. 25, no. 166

22--28

EN

The objective of this article is to present materials and technology for the manufacture of vascular stents with appropriate design requirements. The use of the right material is very important in implantology. A biomaterial introduced into the circulatory system must be biocompatible and hemocompatible. At the same time, it should not initiate toxic, mutagenic, or immunological reactions. Currently, 316L stainless steel (316L SS), nitinol (Ni-Ti alloy) and cobalt-chromium alloy (Co-Cr) are used as standard stent materials. Additionally, drug-containing coatings are used to provide antithrombotic properties. Nowadays, scientists are trying to create biodegradable stents (BDS) using magnesium (Mg) or zinc (Zn) alloys. Laser methods are generally used to manufacture stents using Nd:YAG lasers with a pulse length in the range of several milliseconds. Material removal is based on the ejection of the melt using a high-pressure gas. The result is remelting and heat-affected zones. Various post-processing procedures are necessary to remove residues, including etching and electropolishing. Minimizing the heat-affected zone could be achieved by using femtosecond lasers. Additionally, immersion of the material in water prevents the deposition of residues on the workpiece. Interesting alternatives used in the manufacture of vascular stents are electrospinning or additive techniques. 3D printing enables obtaining of geometrically complex and personalized implants and reduces the consumption of materials and the production of waste.

9

Fabrication and Characterization of Fibrous Polycaprolactone Blended with Natural Green Tea Extracts Using Dual Solvent Systems

Mohd Rashid Ainatul Aqilah Binti, Jaganathan Saravana Kumar, Mohd Khudzari Ahmad Zahran, Ismail Ahmad Fauzi

Autex Research Journal

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2022

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Vol. 22, no. 4

404--410

EN

Nanofibrous dressings serve as an impeccable candidate in the management of wounds. Nanofibrous composites composed of polycaprolactone (PCL) and green tea using dual solvent systems at different ratios were fabricated through electrospinning. Pure PCL electrospun fibers along with composites were characterized by using scanning electron microscopy (SEM), wettability, water uptake analysis, and Fourier transform infrared spectroscopy (FTIR). SEM indicated that fibrous morphology and the diameter of PCL/green tea were smaller for chloroform/ dimethylformamide (DMF) (601 nm) and acetone/DMF (896 nm) than the pure PCL (673 nm and 1,104 nm for chloroform/DMF and acetone/DMF, respectively). Wettability of the fabricated composites was increased, and pure PCL fibers were slightly more hydrophobic (100°) than PCL/green tea (94°). Water uptake of the composites was enhanced compared with PCL significantly in acetone/DMF. The PCL/green tea nanofibrous wound dressing with enhanced physicochemical properties serves as an indispensable candidate for wound healing applications.

10

Simple synthesis of Black TiO2 Nanofibers Via Calcination in Inert Atmosphere

Ji Myeongjun, Kim Eung Ryong, Park Mi-Jeong, Jeon Hee Yeon, Moon Jaeyun, Byun Jongmin, Lee Young-In

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 4

1481--1486

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.

11

Influence of molecular weight on dielectric properties and piezoelectric constant of poly(vinylidene fluoride) membranes obtained by electrospinning

Zahari Aminatul Sobirah, Mazwir Muhammad Hafiz, Misnon Izan Izwan

Polimery

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2021

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T. 66, nr 10

532--537

EN

A significant influence of the molecular weight on the dielectric properties and piezoelectric constant of poly(vinylidene fluoride) (PVDF) membranes obtained by electrospinning was demonstrated. Electrochemical impedance spectroscopy and d33 meter were used to evaluate dielectric properties and piezoelectric constant respectively. The presence of the β-phase was determined by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The membranes with the lowest molecular weight (180,000 g/mol) possessed the best dielectric properties. They also had the highest piezoelectric constant (21 pC/N) and dielectric constant (2.9 at 50 Hz) as well as the highest β-phase content (80.25%).

PL

Wykazano istotny wpływ masy cząsteczkowej na właściwości dielektryczne i stałą piezoelektryczną membran poli(fluorku winylidenu) (PVDF) otrzymanych metodą elektroprzędzenia. Do oceny stałej piezoelektrycznej i właściwości dielektrycznych stosowano, odpowiednio, miernik d33 i spektroskopię impedancyjną. Obecność fazy β określono za pomocą spektroskopii w podczerwieni z transformacją Fouriera (FTIR) i dyfrakcji rentgenowskiej (XRD). Membrany o najmniejszej masie cząsteczkowej (180 000 g/mol) charakteryzowały się najlepszymi właściwościami dielektrycznymi. Miały również największą stałą piezoelektryczną (21 pC/N) i stałą dielektryczną (2,9 przy 50 Hz) oraz największą zawartość fazy β (80,25%).

12

Preparation and Characterisation of Vitamin-Loaded Electrospun Nanofibres as Promising Transdermal Patches

Parın Fatma Nur, Yıldırım Kenan

Fibres & Textiles in Eastern Europe

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2021

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Vol. 29, no. 1 (145)

17--25

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.

13

Improving the Water-Repellent and Antifungal Properties of Electrospun Cellulose Acetate Materials by Decoration with ZnO Nanoparticles

Nachev Nasko, Spasova Mariya, Manolova Nevena, Rashkov Iliya, Naydenov Mladen

Fibres & Textiles in Eastern Europe

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2021

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Vol. 29, no. 3 (147)

40--45

EN

Suitable conditions for the preparation of nano- and microstructured materials from cellulose acetate and cellulose acetate/ZnO from solutions/suspensions in aceton/water by electrospinning/electrospraying were found. The materials obtained were characterised by scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and contact angle measurements. The antifungal activity of the materials obtained against Phaeomoniella chlamydospora, which is one of the main species causing diseases in grapevines, was studied as well. It was found that electrospinning of CA solutions with a concentration of 10 wt% reproducibly resulted in the preparation of defect-free fibres with a mean fibre diameter of ~780 nm. The incorporation of ZnO nanoparticles resulted in the fabrication of hybrid materials with superhydrophobic properties (contact angle 152°). The materials decorated with ZnO possessed antifungal activity against P. chlamydospora. Thus, the fibrous materials of cellulose acetate decorated with ZnO particles obtained can be suitable candidates to find potential application in agriculture for plant protection.

PL

W pracy wskazano odpowiednie warunki do otrzymywania materiałów nano- i mikrostrukturalnych z octanu celulozy i octanu celulozy/ZnO z roztworów/zawiesin w acetonie/wodzie metodą elektroprzędzenia/elektrorozpylania. Uzyskane materiały scharakteryzowano za pomocą skaningowej mikroskopii elektronowej (SEM), dokonano analizy dyfrakcji rentgenowskiej (XRD) oraz pomiarów kąta zwilżania. Zbadano również działanie przeciwgrzybiczne uzyskanych materiałów przeciwko Phaeomoniella chlamydospora, który jest jednym z głównych gatunków wywołujących choroby winorośli. Stwierdzono, że podczas elektroprzędzenia z roztworów CA o stężeniu 10% wag. w sposób powtarzalny otrzymywano włókna wolne od defektów o średniej średnicy ~ 780 nm. Wprowadzenie nanocząstek ZnO zaowocowało wytworzeniem materiałów hybrydowych o właściwościach superhydrofobowych (kąt zwilżania 152°). Materiały z dodatkiem ZnO wykazywały działanie przeciwgrzybiczne przeciwko P. chlamydospora. Stwierdzono, że otrzymane materiały mogą być stosowane w rolnictwie do ochrony roślin.

14

Comparative Analysis of Electrospinning Methods for Producing Fibres and Materials with a Predicted Structure and Complex of Properties

Filatov Ivan, Bokova Elena, Smulskaya Maria, Kapustin Ivan, Pawlowa Maria, Kovalenko Grigory

Fibres & Textiles in Eastern Europe

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2021

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Vol. 29, no. 4 (148)

69--74

EN

Various industrial methods of electrospinning are considered. Experimental data of the results of electrospinning from solutions of chlorinated polyvinyl chloride, polyamide-6/66 and fluoroplastic F-42, obtained by various methods are presented.

PL

Rozważaniom poddano różne przemysłowe metody elektroprzędzenia. Przedstawiono dane doświadczalne wyników elektroprzędzenia z roztworów chlorowanego polichlorku winylu, poliamidu-6/66 i fluoroplastu F-42.

15

Characterization of morphology and optical properties of SnO₂ nanowires prepared by electrospinning

Tański Tomasz, Smok Weronika, Matysiak Wiktor

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e137507

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.

16

The Removal of Reactive Red 141 From Wastewater: A Study of Dye Adsorption Capability of Water-Stable Electrospun Polyvinyl Alcohol Nanofibers

Akduman Çigdem, Morsümbül Seniha, Akçakoca Kumbasar Emriye Perrin

Autex Research Journal

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2021

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Vol. 21, no. 1

20--31

EN

The dye production and its use in textile and related industries resulted in discharge of dye to wastewater. Adsorption for color removal is known as equilibrium separation process, and the resultant decolorization is influenced by physicochemical factors such as adsorbent surface area. The nanofiber membranes prepared by the electrospinning method have controllable nanofiber diameter and pore size distribution (PSD) with a high surface area to volume or mass ratio. In this study, polyvinyl alcohol (PVA) nanofibrous membranes were prepared by the electrospinning method at different collection times such as 3, 5 and 10 h and heat fixated at 130, 150 and 170°C for 10 min, and then, the adsorption capability of PVA nanofiber membranes for Reactive Red 141 from aqueous solution was investigated. In order to make PVA nanofibers stable to water, the nanofibrous membranes were chemically cross-linked by a polycarboxylic acid (1,2,3,4 butanetetracarboxylic acid (BTCA)). PVA nanofibrous membranes were characterized by scanning electron microscopy, thermogravimetric analysis, swelling tests and pore size analysis. The results indicated that BTCA crosslinking improved the thermal and water stability of the nanofibrous structure but has no significant effect on the pore sizes of the membranes. Adsorption of Reactive Red 141 was studied by the batch technique, and it was observed that PVA nanofibers removed approximately >80% of the dye.

17

Fabrication of Multifunctional Nano Gelatin/Zinc Oxide Composite Fibers

Zare Hamed, Nayebzadeh Shahnaz, Davodiroknabadi Abolfazl, Hataminasab Sayyed Hasan

Autex Research Journal

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2021

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Vol. 21, no. 4

403--407

EN

According to health studies, reinforcing gelatin is necessary in order to obtain the multifunctional material. In this study, nano zinc oxide (ZnO; at concentrations of 0.5%, 1% and 1.5%) was doped with gelatin and the solution was electrospun under specific conditions to obtain multifunctional gelatin/ZnO nanofibers. The morphology of the nanofibers was studied by field emission scanning electron microscope (FESEM), and energy-dispersive X-ray spectrometry (EDX) analysis indicated the presence of nano Zn on the surface of gelatin fibers. On the contrary, elemental mapping analysis proved the distribution of nano material along the nano gelatin fibers. The results show that the produced nano gelatin/ZnO composite increases the ultraviolet (UV) blocking of fabric significantly. It is also observed that electrospun gelatin/ZnO nanofibers have excellent bactericidal property against both Bacillus cereus (Gram-positive) and Escherichia coli (Gram-negative) bacteria.

18

Morphology Control of One-Dimensional Gallium Nitride Nanostructures by Modulating the Crystallinity of Sacrificial Gallium Oxide Templates

Ko Yun Taek, Park Mijeong, Park Jingyeong, Moon Jaeyun, Choa Yong-Ho, Lee Young-In

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 3

709--712

EN

In this study, we demonstrated a method of controllably synthesizing one-dimensional nanostructures having a dense or a hollow structure using fibrous sacrificial templates with tunable crystallinity. The fibrous Ga2O3 templates were prepared by calcining the polymer/gallium precursor nanofiber synthesized by an electrospinning process, and their crystallinity was varied by controlling the calcination temperature from 500°C to 900°C. GaN nanostructures were transformed by nitriding the Ga2O3 nanofibers using NH3 gas. All of the transformed GaN nanostructures maintained a one-dimensional structure well and exhibited a diameter of about 50 nm, but their morphology was clearly distinguished according to the crystallinity of the templates. When the templates having a relatively low crystallinity were used, the transformed GaN showed a hollow nanostructure, and as the crystallinity increased, GaN was converted into a denser nanostructure. This morphological difference can be explained as being caused by the difference in the diffusion rate of Ga depending on the crystallinity of Ga2O3 during the conversion from Ga2O3 to GaN. It is expected that this technique will make possible the tubular nanostructure synthesis of nitride functional nanomaterials.

19

Electrostatic fabrication of polymer nanofibers

Czapka Tomasz, Kopaniarz Tomasz, Woś Angelika

Przegląd Elektrotechniczny

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2020

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R. 96, nr 2

174--177

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.

20

Elektroprzędzone nanowłókna polimerowe do zastosowań medycznych

Winkler Angelika, Maliszewska Irena, Czapka Tomasz

Polimery

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2020

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T. 65, nr 1

18--24

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.