Search

Nanofibers of CeO 2 and CuO/CeO 2 were prepared using electrospinning method. Known volumes of aqueous solutions of copper acetate monohydrate and cerium nitrate hexahydrate were mixed with a fixed volume of aqueous polyvinyl pyrrolidone and electrospinning was carried out at 12 kV DC by maintaining the tip to collector distance as 10 cm. The green nanofibers thus obtained were calcined at 500 °C for 3 h. The morphology of the synthesized nanofibers (both green and calcined) was determined by SEM analysis and their elemental composition was verified using XPS and EDX spectroscopy. Green ceria nanofibers had an average diameter of about 130 nm, and the average diameter of the green nanofibers containing 10, 20, 30, 40 and 50 mol. % Cu in ceria were found to be approximately of 124, 117, 114, 108 and 98 nm, respectively. The crystal structure of nanofibers was determined by X-ray diffraction (XRD) which showed the peaks of CeO 2 appearing at 2θ of 28.83° and those for CuO at 47.45°. The average crystallite size of CeO 2 and CuO/CeO 2 were calculated by Debye-Scherer formula and found to be 14 nm for CeO 2 and 9–12 nm for CuO/CeO 2 composites of different copper loadings. [ABSTRACT FROM AUTHOR]

• A high-yield strategy for fabricating composite fabric materials was reported. • The combination of nanofiber fabrics and self-gelling powders was realized. • Developed a Janus membrane (PCL/PAA/PEI-CMC) with wet tissue adhesion. • PCL/PAA/PEI-CMC Janus membrane showed excellent hemostatic effect. • PCL/PAA/PEI-CMC Janus membrane has antibacterial and wound healing function. Powdered hemostatic agents, when encountered with high blood pressure bleeding, are prone to being washed away by the blood flow, and there is a risk of entering the blood vessel to cause thrombosis. Fibrous membrane hemostatic bandages have poor adhesion to the wound and require prolonged press to stop bleeding, which may lead to ischemic necrosis of the tissue. Here, inspired by Collocalia birds to prepare cubilose, we propose a technique that large-particles of self-gelling powders are poured upon nanofibers during the spinning flight path and get Janus composite nanofiber membrane in one step. This Janus structure is an asymmetric wettability structure. The hydrophilic side achieved blood coagulation within 1 min by concentrating coagulation factor. The hydrophobic side is 99.99% free of bacteria and prevents bleeding. In addition, this membrane material has strong adhesion and can gel at 5.3 s, especially it does not need to wipe up the blood on the wet tissue beforehand. It exhibits firm adhere to the bleeding site, and can withstand the bursting pressure of 176 mmHg, much higher than the normal systolic blood pressure of the human body. Compared with medical gauze and commercially available gelatin hemostatic sponges, the hemostasis time is reduced to 1/5 (1.16 ± 0.28 min) and the blood loss is reduced to 1/3 (111 ± 11 mg). Moreover, this membrane has potential to be prepared in a large scale because of electro-blown spinning, and is expected to become a new commercially available material for hemostasis in the future. [ABSTRACT FROM AUTHOR]

The composite membranes consisting of silver nanowires (AgNWs) embedded in polylactic acid (PLA) nanofiber were successfully fabricated by one-pot electrospinning. The PLA/AgNWs composite membranes exhibited immediate silver release and local photothermal effect under NIR irradiation, which contributed to excellent antibacterial property, and simultaneously balanced biocompatibility. [Display omitted] • PLA/AgNWs composite nanofiber as wound dressing was developed by one-pot electrospinning. • Photothermally antibacterial capability of AgNWs was exploited for the first time. • The PLA/AgNWs composite membrane presented high strength, superior flexibility and NIR-induced self-peeling property. • Balanced antibacterial and biocompatible properties were achieved due to NIR-induced silver release and local temperature increase. Bacterial infection is the key factor challenging the success of wound healing. In view of the low and short-term antibacterial effects of traditional wound treatment, a photothermal activated antibacterial platform based on silver nanowires (AgNWs) embedded in polylactic acid (PLA) nanofiber membranes was fabricated by electrospinning in this study. SEM images showed that smooth and continuous PLA/AgNWs composite nanofibers with diameter distribution ranging from 200 to 700 nm were obtained. The composite membranes possess moderate hydrophobicity and self-peeling characters, which may contribute to prevent secondary injury during the removal of the dressing. Excellent water vapor permeability also could meet the requirement of wound dressing. Importantly, the presence of AgNWs endow the PLA/AgNWs membranes with not only enhanced plasticity, but also excellent antibacterial properties due to the near infrared (NIR) triggered silver ion release and local photothermal effect. Such NIR-controlled antibacterial action is also beneficial for achieving good biocompatibility. Therefore, the produced PLA/AgNWs composite nanofiber membrane is expected to be a promising candidate that can prevent bacterial infection and promote skin repair. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel 0D/1D CuBi 2 O 4 @WO 3 nanofiber photocatalyst with step-scheme (S-scheme) heterojunction was fabricated by means of the electrospinning method. • In the CuBi 2 O 4 @WO 3 heterostructures, some smaller CuBi 2 O 4 nanoparticles homogeneously distributed on the surface of WO 3 nanofibers. • The CuBi 2 O 4 @WO 3 composite shows excellent photocatalytic activity for TC degradation under weak visible-light irradiation. • The mechanism and driving force of charge transfer and separation in photocatalytic degradation of TC were discussed. A novel 0D/1D CuBi 2 O 4 @WO 3 nanofiber-membrane photocatalyst with step-scheme (S-scheme) heterojunction was fabricated by means of the electrospinning method. The disintegration of CuBi 2 O 4 microspheres under a high voltage electrospinning process led to the simultaneous formation of CuBi 2 O 4 nanoparticles on WO 3 nanofibers, therefore constructing well dispersed CuBi 2 O 4 @WO 3 nano-heterojunctions. The CuBi 2 O 4 @WO 3 composite photocatalyst followed the S-scheme charge transfer mechanism, which promoted the efficient charge transfer across the interface, thereby solving the problem that the narrow-bandgap CuBi 2 O 4 had strong light-harvesting ability but easy recombination of photo-generated carriers. Moreover, such S-scheme heterojunction also achieved the spatial separation of photo-induced electrons and holes while ensuring the promising redox abilities in both WO 3 and CuBi 2 O 4. Hence, the CuBi 2 O 4 @WO 3 composite photocatalyst exhibited excellent photocatalytic activity for photocatalytic degradation of antibiotics in environmental remediation under weak-visible-light irradiation (5 W LED lamp), and its photocatalytic activity for tetracycline degradation was significantly improved, which was 8.1 times and 3.6 times than that of WO 3 nanofibers and pure CuBi 2 O 4 microspheres, respectively. The radical species trapping tests indicated that·O 2 − and h+ were the main active radicals in the tetracycline photodegradation reaction, and the high-performance liquid chromatography-mass spectrometry test clarified three possible degradation reaction pathways of tetracycline. This work presented a facile method to fabricate 0D/1D CuBi 2 O 4 @WO 3 composite nanofiber photocatalyst with well-dispersed CuBi 2 O 4 @WO 3 nano-heterojunctions, and also provided a new idea for the preparation of new nanocomposite photocatalyst based on electrospinning process. [ABSTRACT FROM AUTHOR]

ZrO 2 –SnO 2 nanocomposition were produced in nanofibers (NFs) form with three various mixing volume ratio by electrospinning technique. The microstructure and morphological characterization of NFs reveals the ternary system of ZrO 2 –SnO 2 –ZrSnO 4. Furthermore, Band gap structure of NFs was varied with the composition ratio which consequently affect the Flash sintering (FS) event. The FS experiments were utilized under thermal (844–878 °C) and electric field (420 V/mm) with 3.77 mA/mm2 current cutoff. Highly dense nanocomposition were obtained in less than 80secs with a max power absorption of 1.58 W/mm3. Thanks to low sintering temperature and time, nanostructured surface morphology were acquired which is crucial for biochemical properties of nanocompositions. Drosophila melanogaster food was covered with sintered nanocompositions and the control food. The toxicity of the nanomaterial in the insect, survival rate(%), development time(days) were investigated. In order to support the results, biochemical analyzes (total oxidative level-TOS, total antioxidant level-TAS and oxidative stress index-OSI) were performed in adults. In addition, antimicrobial activity was evaluated with Escherichia coli and Staphylococcus aureus. It was determined that the nanomaterials had an antimicrobial effect along with non-toxic effect on the insect. Besides, it did not change the survival rate of the insect in all groups. Although there was a one-day difference in development times, it did not cause a statistical change in the OSIs of female and male individuals. We believe that the synthesized nanocompositions can be used as a valid candidate in the healthcare system, such as dental implants, due to its antimicrobial effect and non-toxicity in the model organism. [Display omitted] • The ternary system of ZrO 2 –SnO 2 –ZrSnO 4 CNFs were produced by electrospinning technique. • As the volume of SnO 2 increases in the CNFs, diameters of the fibers tend to decrease along with decrement in the band gap. • The max power absorption of 1.58 W/mm3 in flash sintering let to highly dense nanocompositions in less than 80secs. • Sintered nanocompositions were revealed antimicrobial activity both on E. coli and S. aureus. • No increases the toxicity (survival rate, development time and oxidative stress index) was observed in the model organism. [ABSTRACT FROM AUTHOR]

The development of a facile strategy to fabricate inexpensive and efficient nonnoble metal-based alloys to replace their traditionally costly noble-metal counterparts for electrocatalytic water splitting holds great appeal. Here, we report novel FeNi-FeCo-C composite nanofibers (FeNi-FeCo-C CNFs), which was prepared simply by electrospinning a precursor solution containing Fe, Ni and Co nitrates together with polyacrylonitrile powders and subsequent thermal treatment. The optimal FeNi-FeCo-C CNFs prepared with 10 wt% polyacrylonitrile at a thermal treatment temperature of 800 °C show excellent electrocatalytic performance for oxygen evolution in a 1 mol·L−1 KOH aqueous solution with a relatively small overpotential of 262 mV at 10 mA cm−2, a low Tafel slope of 47.2 mV dec−1, and excellent cycling stability. The present strategy will provide new insight for the design and fabrication of electrocatalysts for water splitting. [Display omitted] • Novel FeNi-FeCo-C composite nanofibers. • Facile and highly efficient synthesis method based on electrospinning. • High efficient electrocatalyst for oxygen evolution in water splitting. • Mechanism for improved electrocatalytic activity. [ABSTRACT FROM AUTHOR]

In the present study, the carbon/MWCNT/Fe 3 O 4 composite nanofibers were prepared by electrospinning process and their application was investigated for simultaneous degradation of phenol and paracetamol through the photo-like-Fenton process. The prepared nanofibers were characterized using SEM and XRD analysis. The Box–Behnken design was used to evaluate the relation between the photo-like-Fenton operating variables including pH (3–5), initial concentrations of phenol and paracetamol (50–250 mg/L), H 2 O 2 concentration (5–25 mmol/L), reaction time (5–25 min), temperature (35–55 °C) and carbon/MWCNT/Fe 3 O 4 nanofiber dosage (0.05–0.10 g/L) on the phenol and paracetamol removing. The experimental design results showed that the experimental maximum phenol and paracetamol degradation efficiencies were found to be 99.9% and 99.0% at pH of 3.4, phenol and paracetamol concentrations of 50 mg/L, H 2 O 2 concentration of 15 mmol/L, reaction time of 25 min, temperature of 45 °C and nanofiber dosage of 0.075 g/L. The prepared carbon/MWCNT/Fe 3 O 4 nanofiber were successfully reused for five times after regeneration. The obtained results revealed the high potential of carbon/MWCNT/Fe 3 O 4 composite nanofibers for a short-time mineralization of phenolic compounds from wastewater during photo-like-Fenton process. [ABSTRACT FROM AUTHOR]

In this work, magnetic Fe 3 O 4 nanoparticles (NPs) were utilized to improve the mechanical and antibacterial properties of chitosan (CS)/gelatin (GE) composite nanofiber membranes. Homogeneous Fe 3 O 4 /CS/GE nanofibers were electrospun successfully. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images confirmed the presence of well-dispersed Fe 3 O 4 NPs in the composite nanofibers. Fourier transform infrared spectroscopy (FTIR) spectra revealed the effective interactions of Fe 3 O 4 NPs to the composite matrix through hydrogen bonding. The improvement on the thermal stability of the Fe 3 O 4 /CS/GE was observed by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), which is tightly correlated to strong filler-matrix adhesion. The incorporation of Fe 3 O 4 NPs resulted in a substantial enhancement of mechanical properties. The optimum mechanical performance was demonstrated on 1 wt% Fe 3 O 4 /CS/GE nanofiber membranes, achieving 155% augment of Young's modulus, 128% increase of tensile strength, and 100% boost of toughness from CS/GE. The excellent mechanical enhancement can be explained by the effective dispersion of fillers and the filler-matrix interactions, which ensures the efficient load transfer from CS/GE matrix to Fe 3 O 4 nanofillers. Moreover, zones of inhibition for Escherichia coli and Staphylococcus aureus expanded markedly with the supplement of Fe 3 O 4 NPs. In all, nanofiber membranes made of Fe 3 O 4 /CS/GE composite with tailored mechanical and antibacterial properties appear a promising wound dressing material. [ABSTRACT FROM AUTHOR]

Carbon quantum dots/titanium dioxide (CQDs/TiO 2 ) composite nanofibers were prepared via a facile one step hydrothermal method. Characterization of the samples was carried out by Field-emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Photoluminescence (PL), and Fourier transformed infrared (FT-IR) spectroscopy. Our study revealed that the photocatalytic efficiency (photodegradation of methylene blue) under visible light irradiation and antibacterial properties (against Escherichia coli ) of as prepared composite nanofibers (CQDs/TiO 2 ) are higher than pristine TiO 2 nanofibers. The anchored CQDs can both enhance the light absorption and suppress photogenerated electron–hole׳s recombination which results in the enhancement of catalytic and antibacterial properties. [ABSTRACT FROM AUTHOR]

This study was carried out to examine the effect of different solvents (DMSO, NMP, DMF) and solvent mixtures, application of dispersion and mixing techniques during solution preparation and redoping process on polyacrylonitrile (PAN) and camphorsulfonic acid (CSA) doped polyaniline (PANI) composite nanofibers. It was observed that nanofibers produced from DMSO and NMP solvents had larger fiber diameters than nanofibers produced from DMF. When the crystallinity of the 100 % PAN nanofibers were compared, the nanofibers electrospun from DMSO had the lowest crystallinity values. The tensile breaking stress values of the nanowebs produced from DMSO and NMP were higher than nanowebs produced from DMF while the breaking elongation values of the nanowebs produced from DMF was higher. Mechanical dispersion technique resulted in higher tensile breaking stress values than corresponding magnetic stirring. The redoping process also affected the tensile properties of the nanowebs by increasing the breaking stress values and decreasing the breaking elongation values. When DMSO was used as a solvent for the production of composite nanofibers, the electrical conductivity values at around 10 S/cm were obtained corresponding to the semiconductive material range. The use of solvent mixtures resulted in better conductivity values than their counterparts. When CSA-NMP and CSA-NMP/DMF were compared, the nanofibers produced from the solvent mixture had higher conductivity values. On redoping, the conductivity increased 10 times and reached 1.2×10 S/cm. The reference samples with DMSO had the lowest cyclization temperature and enthalpy. Addition of PANI increased the thermal stability of the composite nanofibers in comparison with pure PAN. [ABSTRACT FROM AUTHOR]

Using electrospinning technique to prepare chitosan (CS) nanofibers from an inexpensive solvent such as acetic acid has been a challenge, due to the lack of sufficient entanglements in these semi-rigid polyelectrolytes. Incorporating polymers such as poly(methacrylic acid) (PMAA) into the solution lowers the entanglement concentration of the polymers, and make all three morphology regimes (polymer droplets, beaded nanofibers and nanofibers with uniform thickness) accessible to electrospinning method. Uniform composite nanofibers are found at concentrations well above the entanglement concentration. The thickness and morphology of nanofibers can be regulated by addition of small amount of organic solvents such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). The composite nanofibers are subsequently crosslinked at an elevated temperature to improve their thermal and solvent stability. The mechanical properties of the crosslinked CS/PMAA fibers can be modulated by varying the amount and molecular weight of PMAA incorporated in the blend. The composite fiber materials provide a useful platform to support a variety of catalysts. As a demonstration, palladium catalyst has been immobilized on the crosslinked CS/PMAA nanofibers to carry out Mizoroki–Heck cross-coupling reactions of aromatic halides and acrylates. We found remarkable catalytic efficiency and stability in these materials. We also demonstrate that, by the “post-modification” of the nanofibers with ligands that chelate metal catalysts, a variety of metal catalysts can be incorporated into the fiber platform, with further improved stability and activity. [ABSTRACT FROM AUTHOR]

Electrospinning of conductive polymer blends offers high potential to prepare novel materials for electronical applications. The main aim of this work is to fabricate poly(vinyl alcohol) (PVA), polyaniline (PANI), and multi walled carbon nanotubes (MWNT) composites in thin film and nanofiber layer structures and then compare their microwave absorption behavior. First, optimum ratios for blending PVA, PANI, Camphorsulfonic acid (CSA) and MWNT were obtained. Then under optimized ratios, composite solutions of PVA: PANI-CSA, and PVA/PANI-CSA/MWNT were fabricated to nanofiber layer and thin film structures. Based on scanning electron microscope (SEM) micrographs, the PVA/PANI-CSA nanofiber samples at low content of PANI-CSA presented a very uniform surface and without any beads but some beads started to develop at higher PANI-CSA content. However, the SEM analysis of the PVA/PANI-CSA/MWNT films revealed the uniform appearance for all composites. But, some aggregation and local irregularities on the surface were observed due to the presence of MWNT in the composite structure. Microwave absorption behavior was evaluated using vector network analyzers in the frequency range of 8-12 GHz (X-band) for all samples. It was observed that absorption microwave properties of PVA/PANI-CSA nanofibers improved with increasing in the loading levels of PANI-CSA in the mixture. Microwave absorption properties of the PVA/PANI-CSA/MWNT composite nanofiber absorbers have been compared with thin films at various thicknesses by measuring the relative maximum reflection loss (dB/mm) of samples. The PVA/PANI-CSA/MWNT composite nanofibers with the layer thickness of 0.1 mm presented two remarkable absorbing peaks versus one absorbing peak in nanocomposite films with similar thickness. The relative maximum reflection loss in PVA/PANI-CSA/MWNT composite nanofiber has reached -230 dB/mm at frequency of 8.6 GHz which is nearly 8 times higher than -28 dB/mm at frequency of 8.4 GHz for PVA/PANI-CSA/MWNT film samples. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In this study, chitosan/polyvinyl alcohol binary and tannic acid/chitosan/polyvinyl alcohol ternary composite nanofiber membranes from chitosan citric acid salt aqueous solutions without the use of toxic solvents through Forcespinning® technology were successfully mass produced. Chitosan is being widely evaluated as a wound dressing material based on its biocompatibility, biodegradability, and antibacterial properties. Tannic acid has been applied as a drug for the treatment of wounds due to its astringent, antioxidant, hemostatic, and antibacterial properties. The ternary composite nanofiber membranes were in situ crosslinked to become water stable, in order to be used as wound dressings. The morphology, structure, water stability, water absorption capability, and thermal and mechanical properties of the composite nanofibers were characterized. The antibacterial activity was evaluated by the viable cell-counting method. The ternary composite nanofibers demonstrated synergistic antibacterial activity against Escherichia coli. The ternary composite membranes were found to be beneficial to the adhesion and development of fibroblast cells. These composite nanofiber membranes have the potential to be used in wound dressing applications. [ABSTRACT FROM AUTHOR]

Nanofibrous membrane scaffolds of chitosan (CS), silk fibroin (SF) and CS/SF blend were prepared by electrospinning and studied for growth and osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs). The morphology and physico-chemical properties of all membrane scaffolds were compared. The influence of CS and SF on cell proliferation was assessed by the MTS assay, whereas osteogenic differentiation was determined from the Alizarin Red staining, alkaline phosphatase activity and expression of osteogenic marker genes. The osteogenic differentiation and proliferation of hMSCs were enhanced by CS and SF nanofibers, respectively. Blending CS with SF retained the osteogenesis nature of CS without negatively influencing the cell proliferative effect of SF. By taking advantage of the differentiation/proliferation cues from individual components, the electrospun CS/SF composite nanofibrous membrane scaffold is suitable for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Abstract: Si/C/TiO2 composite nanofibers have been prepared via a facile electrospinning method combined with a sol–gel chemistry, whose electrochemical performance as anode materials in lithium-ion battery was evaluated. As-prepared nanofibers (NFs) were characterized using scanning electron microscopy, energy dispersive spectroscopy, powder X-ray diffraction and thermogravimetric analyzer to identify their morphology, phase, crystallinity and compositions. Rutile phase TiO2 nanofibers demonstrated a relatively low gravimetric specific capacity of ∼83 mAh g−1 when discharged at 0.1C. In contrast, composite nanofibers possess a much higher gravimetric specific capacity. When the Si to C mass ratio is of 0.217, a specific capacity as high as 720 mAh g−1 can be attained, 94% of which can be maintained after 55 cycles. The enhanced cycling stability of micron silicon materials is attributed to the space confinement provided by the structurally stable TiO2. These findings can provide a beneficial guidance for future lithium ion battery electrode development. [Copyright &y& Elsevier]

Abstract: Composite nanofiber sheets containing multiwalled carbon nanotubes and cobalt chloride dispersed in PAN (polyacrylonitrile) were produced by an electrospinning technique. The synthesized PAN/CoCl2/CNTs composite nanofiber was used as the catalyst for hydrogen production from the hydrolysis of sodium borohydride. FT-IR characterization showed that the pretreated CNTs possess different organic functional groups which help improve the compatibility between CNTs and PAN organic polymer. SEM (scanning electron microscopy), TEM (transmission electron microscopy) and EDX (energy-dispersive X-ray technique) were used to characterize the composite nanofiber and it was found that CNTs can be coaxially dispersed into the PAN nanofiber. During the hydrolysis of NaBH4, this PAN/CoCl2/CNTs composite nanofiber exhibited higher catalytic activity compared to the composite without CNTs doping. Kinetic analysis of NaBH4 hydrolysis shows that the reaction of NaBH4 hydrolysis based on this catalyst can be ascribed to the first-order reaction and the activation energy of the catalyst was approximately 52.857 kJ/mol. Meanwhile, the composite nanofiber catalyst shows excellent stability and reusability in the recycling experiment. [Copyright &y& Elsevier]

Abstract: Short composite nanofibers were fabricated by electrospinning polymer/TiO2 nanoparticle solutions of 13 wt. % cellulose acetate as a polymer under a voltage of 5.5 kV and at a flow rate of 0.1 μL/min, and the nanoparticles could be added in concentrations as high as 50 wt. %. The length of the short composite nanofibers was significantly decreased from 112 to 70 μm by the addition of at least a 5 wt. % concentration of nanoparticles, and it gradually continued to decrease as the nanoparticle concentration was increased. The length of the short composite nanofibers with a low concentration of nanoparticles was affected by the surface charge of the nanoparticles, and negatively charged nanoparticles readily dispersed to the negatively charged polymers in solution, which resulted in an elongation of the fabricated short composite nanofibers. [Copyright &y& Elsevier]

Abstract: Silk fibroin (SF) from Bombyx mori has many established excellent properties and has found various applications in the biomedical field. However, some abilities or capacities of SF still need improving to meet the need for using practically. Indeed, diverse SF-based composite biomaterials have been developed. Here we report the feasibility of fabricating pantothenic acid (vitamin B5, VB5)-reinforcing SF nanofibrous matrices for biomedical applications through green electrospinning. Results demonstrated the successful loading of d-pantothenic acid hemicalcium salt (VB5-hs) into resulting composite nanofibers. The introduction of VB5-hs did not alter the smooth ribbon-like morphology and the silk I structure of SF, but significantly decreased the mean width of SF fibers. SF conformation transformed into β-sheet from random coil when composite nanofibrous matrices were exposed to 75% (v/v) ethanol vapor. Furthermore, nanofibers still remained good morphology after being soaked in water environment for five days. Interestingly, as-prepared composite nanofibrous matrices supported a higher level of cell viability, especially in a long culture period and significantly assisted skin cells to survive under oxidative stress compared with pure SF nanofibrous matrices. These findings provide a basis for further extending the application of SF in the biomedical field, especially in the personal skin-care field. [Copyright &y& Elsevier]

Highlights: [•] Chitosan/hydroxyapatite nanofiber was prepared by electrospinning. [•] The fiber diameter was in good agreement by the Box–Behnken Design analysis. [•] The selectivity adsorption was in order of lead>cobalt>nickel. [•] The metals adsorption capacity did not change after five sorption–desorption cycles. [Copyright &y& Elsevier]

Highlights: [•] We prepared three types of SnO2/TiO2 composite nanofibers via a facile electrospinning method. [•] Both SnO2 and TiO2 in these fibers are identified as a rutile phase by XRD and Raman Spectroscopy. [•] Composite nanofibers show superior electrochemical performance to pure TiO2 and SnO2fibers. [•] The enhanced cycling stability is due to the space confinement provided by the stable TiO2 matrix. [ABSTRACT FROM AUTHOR]

Abstract: Alloy anodes (Si, Ge and Sn) electrospun into carbon nanofibers as binder-free electrodes were synthesized and studied for rechargeable lithium-ion batteries. Alloy anode materials suffer from serious volume changes and nanoparticle aggregations during lithium insertion and extraction, resulting in rapid pulverization and capacity loss. Carbon nanofibers could help preserve the alloy anode materials during repeated cycling, and consequently maintain the cycling stability. In this work, it was found that with the increase in the amount of Si, Ge and Sn, the cycling stability was decreased due to the formation of large clusters within the carbon nanofiber matrix. Compared with Si/carbon nanofibers, Ge/carbon and Sn/carbon exhibited better cycling performance due to their improved nanoparticle distribution and smaller volume changes. The failure mechanism of the Si/carbon structure was explained in this article. It is believed that this study on Si/carbon, Ge/carbon and Sn/carbon composite nanofiber electrodes could help in designing alloy-based carbon composites with various structures for advanced lithium-ion batteries. [Copyright &y& Elsevier]

Direct utilization of methane fuels in solid oxide fuel cells (SOFCs) is a key technology to realize the immediate inclusion of such high-efficiency fuel cells into the current electricity generation infrastructure. However, the broad commercialization of direct-methane fueled SOFCs is critically hindered by the inadequate electrode activity and their poor longevity, which primarily stems from the carbon build-up issues. To make the technology more competitive, a novel electrode structure that can dramatically improve the tolerance against coking is essential. Herein, we present highly active and robust core-shell nanofiber anodes, La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3 @Sm 0.2 Ce 0.8 O 1.9 (LSCM@SDC), directly obtained with a single-nozzle electrospinning process through the use of two immiscible polymers. The intimate coverage of SDC on LSCM not only increases the active reaction sites but also promotes resistance toward carbon deposition and thermal aggregation. As such, the electrode polarization resistance obtained with LSCM@SDC NFs is among the lowest value ever reported with LSCM derivatives (∼0.11 Ω cm 2 in wet H 2 at 800 °C). The facile fabrication process of such complex heterostructures developed in this work is attractive for the design of not only SOFC electrodes but also other solid-state devices such as electrolysis cells, membrane reformers, and protonic cells.

Wearable energy harvesters and sensors have recently attracted significant attention with the rapid development of artificial intelligence and the Internet of Things (IoT). Compared to high-output bulk materials, these wearable devices are mainly fabricated by thin-film-based materials that limit their application. Therefore, the enhancement of output voltage and power for these devices has recently become an urgent topic. In this paper, the lead-free bismuth titanate-barium titanate (0.93(Na0.5Bi0.5)TiO3-0.07BaTiO3(BNBT)) nanoparticles and nanofibers were embedded into the PVDF nanofibers. They produced high inorganic electrical voltage coefficients, high electromechanical coupling coefficients, and environmentally friendly properties that enhance the electromechanical performance of pure PVDF nanofibers, and they are all the critical requirements for modern flexible pressure sensors. In detail, PVDF and PVDF-based composites nanofibers were prepared by electrospinning, and different flexible sandwich composite devices were fabricated by the PDMS encapsulation method. As a result, the six-time enhancement maximum output voltage was obtained in a PVDF-BNBT (fiber)-based composite sensor compared to the pure PVDF one. Our results indicate that the output voltage of the pressure sensors has been significantly enhanced, and the development gate is enabled by analyzing the related physical process and influence mechanism. [ABSTRACT FROM AUTHOR]

Chemical oxidative polymerization of N-Methyl Pyrrole (NMPy) by cerium(IV) on Poly(Acrylonitrile-co-Vinyl Acetate) matrix in N,N-dimethylformamide (DMF) was performed. Electrospinning technique was used for the preparation of P(AN-co-VAc) solutions with uniformly distributed Poly(N-Methyl Pyrrole) (PNMPy) nanoparticles. In the presence of PNMPy, a new absorption band appeared at 1312 cm-1 which corresponds to CH in plane vibration peak. The dielectric properties of nanofiber composites were evaluated on the basis of the complex permittivity. The SEM and AFM images of composite nanofibers showed that the PNMPy nanoparticles with the dimensions of 20-40 nm were distributed homogeneously. [ABSTRACT FROM AUTHOR]

Abstract: Recent trends in scaffold design have focused on materials that can provide appropriate guidance cues for particular cell types to modulate cell behavior. In this study highly aligned and electrically conductive nanofibers that can simultaneously provide topographical and electrical cues for cells were developed. Thereafter their potential to serve as functional scaffolds for skeletal muscle tissue engineering was investigated. Well-ordered nanofibers, composed of polyaniline (PANi) and poly(ε-caprolactone) (PCL), were electrospun by introducing an external magnetic field in the collector region. Incorporation of PANi into PCL fibers significantly increased the electrical conductivity from a non-detectable level for the pure PCL fibers to 63.6±6.6mScm−1 for the fibers containing 3wt.% PANi (PCL/PANi-3). To investigate the synergistic effects of topographical and electrical cues using the electrospun scaffolds on skeletal myoblast differentiation, mouse C2C12 myoblasts were cultured on random PCL (R-PCL), aligned PCL (A-PCL), random PCL/PANi-3 (R-PCL/PANi) and aligned PCL/PANi-3 (A-PCL/PANi) nanofibers. Our results showed that the aligned nanofibers (A-PCL and A-PCL/PANi) could guide myoblast orientation and promote myotube formation (i.e. approximately 40% and 80% increases in myotube numbers) compared with R-PCL scaffolds. In addition, electrically conductive A-PCL/PANi nanofibers further enhanced myotube maturation (i.e. approximately 30% and 23% or 15% and 18% increases in the fusion and maturation indices) compared with non-conductive A-PCL scaffolds or R-PCL/PANi. These results demonstrated that a combined effect of both guidance cues was more effective than an individual cue, suggesting a potential use of A-PCL/PANi nanofibers for skeletal muscle regeneration. [Copyright &y& Elsevier]

Composite nanofibers of Poly(butylene terephthalate) (PBT)/multiwalled-carbon nanotubes (MWCNTs) were prepared by electrospinning technique in the form of a random fibers web. The effect of MWCNTs on the morphology, crystallinity, and mechanical properties of the electrospun composite nanofibers was investigated by SEM, DSC, and tensile testing, respectively. SEM observations indicated that the presence of MWCNTs resulted in finer nanofibers for lower loading; however, a broader diameter was found for nanofibers with higher amounts of carbon nanotubes.It was also observed that the melt-crystallization temperature (Tc) of PBT nanofibers shifted to a higher temperature (about 8 °C) by the incorporation of MWCNTs which might be due to the nucleating effect of the nanotubes. The mechanical properties (specific strength and modulus) of the PBT nanofibers were significantly enhanced by the incorporation of MWCNTs. [ABSTRACT FROM AUTHOR]

Bone disease and disorder treatment might be difficult because of its complicated nature. Millions of patients each year need bone substitutes that may help them recover quickly from a variety of illnesses. Synthetic bone replacements that mirror the structural, chemical, and biological features of bone matrix structure will be very helpful and in high demand. In this research, the inorganic bioactive glass nanoparticles matrixed with organic collagen and silk fibroin structure (COL/SF/CaO-SiO 2 ) were used to create multifunctional bone-like fibers in this study, which we describe here. The fiber structure is organized in a layered fashion comparable to the sequence in which apatite and neo tissue are formed. The amino groups in COL and SF combined with CaO-SiO 2 to stabilize the resulting composite nanofiber. Morphological and functional studies confirmed that crystalline CaO-SiO 2 nanoparticles with average sizes of 20 ± 5 nm are anchored on a 115 ± 10 nm COL/SF nanofiber matrix. X-ray photoelectron spectroscopic (XPS) results confirmed the presence of C, N, O, Ca, and Si in the composite fiber with an atomic percentage of 59.46, 3.30, 20.25, 3.38 and 13.61%. respectively. The biocompatibility examination with osteoblast cells (Saos-2) revealed that the CAL/SF/CaO-SiO 2 composite nanofiber had enhanced osteogenic activity. Finally, when the CAL/SF/CaO-SiO 2 composite nanofiber scaffolds were used to treat an osteoporotic bone defect in a rat model, the composite nanofiber scaffolds significantly promoted bone regeneration and vascularization. This novel fibrous scaffold class represents a potential breakthrough in the design of advanced materials for complicated bone regeneration., Competing Interests: We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled “Fabrication of Biologically Inspired Electrospun Collagen/Silk fibroin/Bioactive glass composited Nanofibrous scaffold to accelerate the Treatment efficiency of Bone repair”., (© 2022 The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V.)

Hydrogen production from NaBH4 hydrolysis is very important for environment-friendly fuel cells. Here Y-zeolite/CoCl2 doped PVDF (Polyvinylidene fluoride) composite nanofibers were prepared by co-electrospinning method and successfully applied into hydrogen production from NaBH4 hydrolysis. The effect of Y-zeolite doping on properties of composite nanofibers was investigated in detail. SEM, EDX (Energy-dispersive X-ray spectroscopy) and FT-IR characterization showed that nanosized crystalline Y-zeolite can be doped into the bulk of composite nanofiber and high-quality composite nanofiber with fine morphologies can be obtained. The doping of Y-zeolite can improve the wetting ability of PVDF-based nanofiber and thus help to the diffusion rate of reactants. This Y-zeolite/CoCl2 doped electrospun nanofiber as catalyst were applied into hydrogen production from NaBH4 hydrolysis and exhibits higher catalytic activity compared with that without Y-zeolite doping due to its improved surface hydrophilicity. Meanwhile, this composite nanofiber catalyst shows relatively good stability in hydrogen production without obvious loss of Y-zeolite. [Copyright &y& Elsevier]

Abstract: Electrospun nanofibrous membranes (ENMs) are considered as a state of the art in water filtration technology mainly owing to their high interconnected porosity and tunable pore size assumed to offer a very high permeability also selectivity. However, the extremely high surface area makes the ENMs prone to mechanical breakdown and lack of wettability lowering the filtration efficiency. Hence, any attempt to enhance both the mechanical properties and hydrophilicity of the ENMs is highly recommended. In the current study, the structural and transport properties of polyethersulfone (PES) ENMs were modified through incorporation of titania (TiO2) nanoparticles via a sol–gel approach. Presence of titania precursor increased the conductivity of the electrospun solution thereby optimized the structural features of the electrospun mat in terms of formation of very thin beadless nanofibers, a higher porosity and smaller pore size. Moreover, a significant rise in mechanical properties, thermal stability and switching from a highly hydrophobic membrane to a superhydrophilic one occur simultaneously. The combination of a more optimum porosity, very high mechanical properties and hydrophilicity leads to a significantly higher water permeability in the TiO2/PES ENMs encouraging us to propose it as a water filtration membrane with longer life span and lower energy consumption. [Copyright &y& Elsevier]

The oxidative polymerization of pyrrole (Py) by cerium(IV) on Poly(Acrylonitrile- co-Vinyl Acetate) matrix was performed. Nanofibers were obtained from this solution by the electrospinning method. A new absorption band was observed corresponding to the CH in plane vibration of polypyrrole (PPy) by Fourier transform infrared-attenuated total reflectance spectrophotometric analysis. A linear relationship was determined between the absorbance ratios of functional groups corresponding to the conjugated polymeric units and initial Py concentrations in the presence and absence of Py. Scanning electron microscope images indicated that the diameters of nanofibers were dependent on PPy content and that the average nanofiber diameters were reduced with increasing the initially added Py concentration. The alternating current conductivity of nanofibers was increased with frequency, particularly in the higher frequency region (> 105 Hz). [ABSTRACT FROM PUBLISHER]

Abstract: Collagen functionalized thermoplastic polyurethane nanofibers (TPU/collagen) were successfully produced by coaxial electrospinning technique with a goal to develop biomedical scaffold. A series of tests were conducted to characterize the compound nanofiber and its membrane in this study. Surface morphology and interior structure of the ultrafine fibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM), whereas the fiber diameter distribution was also measured. The crosslinked membranes were also characterized by SEM. Porosities of different kinds of electrospun mats were determined. The surface chemistry and chemical composition of collagen/TPU coaxial nanofibrous membranes were verified by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometry (FTIR). Mechanical measurements were carried out by applying tensile test loads to samples which were prepared from electrospun ultra fine non-woven fiber mats. The coaxial electrospun nanofibers were further investigated as a promising scaffold for PIECs culture. The results demonstrated that coaxial electrospun composite nanofibers had the characters of native extracellular matrix and may be used effectively as an alternative material for tissue engineering and functional biomaterials. [Copyright &y& Elsevier]

An efficient, environmentally compatible and highly porous, silver surface-modified photocatalytic zinc oxide/cellulose acetate/ polypyrrole ZnO/CA/Ppy hybrid nanofibers matrix was fabricated using an electrospinning technique. Electrospinning parameters such as solution flow rate, applied voltage and the distance between needles to collector were optimized. The optimum homogenous and uniform ZnO/CA/Ppy polymeric composite nanofiber was fabricated through the dispersion of 0.05% wt ZnO into the dissolved hybrid polymeric solution with an average nanofiber diameter ranged between 125 and 170 nm. The fabricated ZnO-polymeric nanofiber was further surface-immobilized with silver nanoparticles to enhance its photocatalytic activity through the reduction of the nanofiber bandgap. A comparative study between ZnO polymeric nanofiber before and after silver immobilization was investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and thermal gravimetric analysis (TGA). The photocatalytic degradation efficiency of the two different prepared nanofibers before and after nanosilver immobilization for malachite green (MG) dye was compared against various experimental parameters. The optimum degradation efficiency of nanosilver surface-modified ZnO-polymeric nanofibers was recorded as 93.5% for malachite green dye after 1 h compared with 63% for ZnO-polymeric nanofibers. [ABSTRACT FROM AUTHOR]

• Cellulose nanocrystal (CNCs) are environment-friendly nanofillers for electrospun nanofibers. • CNC-Polyamide 6 (PA-6) composite nanofiber air filters were fabricated by using the electrospinning method. • Effect of nanofiber composition on both mechanical properties and toluene adsorption performance were examined. • Composite nanofiber filters reached to 50% toluene adsorption after 45 min. The cellulose nanocrystal (CNC)-polyamide 6 (PA-6) composite nanofiber filters were fabricated and examined their structural and mechanical properties and toluene adsorption performances. The effect of polymer concentration (13 wt% and 17 wt%) and CNC ratio (0, 1.0 wt%, 1.5 wt%, and 2.0 wt%) on the characteristics and adsorption abilities of nanofiber filters were investigated. The nanofiber filter including 17 wt% PA-6 and 1.5 wt% CNC has shown the best toluene adsorption efficiency of 50% and improved mechanical properties. As a result, the nanofiber filter having CNC are effective, accessible and cost-saving materials and has been a good candidate as the toluene vapor capture media and it has nearly same removal efficiency like the conventional adsorbents with powder or particle forms. The resultant filters had excellent three-dimensional (3D) fiber structure having micro/nanopores and they can be used in potential applications such as catalyst supports, indoor air filter and respiration masks. [ABSTRACT FROM AUTHOR]

Here, we developed a novel biliary stent coating material that is composed of tri-layer membrane with dual function of sustained release of paclitaxel (PTX) anticancer drug and antibacterial effect. The advantages of using electrospinning technique were considered for the even distribution of PTX and controlled release profile from the nanofiber mat. Furthermore, film cast method was utilized to fabricate AgNPs-immobilized PU film to direct the release towards the tumor site and suppress the biofilm formation. The in vitro antibacterial test conducted against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria species showed excellent antibacterial effect. The in vitro drug release study confirmed the sustained release of PTX from the tri-layer membrane and the release profile fitted first order with correlation coefficient of R2 = 0.98. Furthermore, the release mechanism was studied using Korsmeyer–Peppas model, revealing that the release mechanism follows Fickian diffusion. Based on the results, this novel tri-layer membrane shows curative potential in clinical development. [ABSTRACT FROM AUTHOR]

Herein, a unique hierarchically structured composite nanofiber membrane, consisting of a zeolitic imidazolate framework-8-embedded polyethersulfone (PES@ZIF8) fiber layer and a polysulfonamide/polyethersulfone (PSA/PES) fiber layer, was successfully developed to cope with the complex environments during the actual filtration/separation process and overcome the conflict between high filtration efficiency and low air pressure resistance. Due to the advantages of the synergistic effect of multicomponents and the bi-layer hierarchical structure, the integrated PES@ZIF8-PSA/PES filter possesses an extremely high air filtration efficiency (up to 99.986%) under a very low pressure drop (only 15 Pa), superior PM 0.3 purification capacity (close to 99.95%), long-term recycling ability for purifying real smoke PM 2.5 from >800 to <10 μg/m 3 , extremely high temperature resistance (exceed 200 °C), flame retardancy, good chemical stability, satisfactory transmittance, and robust self-cleaning ability. Apart from these, it achieves effective separation of oil-water mixtures and oil-water emulsions as a result of selective wettability including hydrophobicity and superoleophilicity. In particular, the PES@ZIF8-PSA/PES nanofiber membranes maintain outstanding air filtration and oil/water separation properties under the high temperature or strong acid/alkali conditions. This special comprehensive performance gives the PES@ZIF8-PSA/PES-based filtration/separation membranes a wider application prospect ranging from environmental governance to individual protection and industrial security.

An electrospun nanofiber membrane significantly improves the electrical performances of triboelectric nanogenerators (TENGs) due to its high surface area. In recent years, composite nanofibers were applied to a TENG using various electrospinning system types to further enhance the performance of TENGs; however, the effects of the systems on the energy harvesting capability of TENGs have not been investigated thoroughly. This study aims to fabricate polyimide/poly(vinylidene fluoride- co -trifluoroethylene) composite nanofiber-based TENGs with three different nozzle systems: single nozzle, conjugated nozzle, and multinozzles, and two different collectors: plate collector and drum collector. A TENG with multinozzle-drum system-based nanofibers produced an output voltage of 364 V, a short-circuit current of 17.2 μA, a transferred charge of 29.72 nC, and a power density of 2.56 W/m 2 at a load resistance of 100 MΩ, which were ∼7 times higher than those of other system-based nanofibers. Under the 10,000 cycles of loading, the TENG stably harvested electric energy. The TENG could also harvest energy from the human body motions, and it is sufficient to illuminate 117 light-emitting diodes and drive several electronic devices. The proposed TENG exhibits excellent electric performances as a wearable energy harvester.

To meet the growing clinical demand for small-caliber blood vessel grafts to treat cardiovascular diseases, it is necessary to develop safe and long-term unobstructed grafts. In this study, a biodegradable graft made of composite nanofibers is introduced. A composite nanofiber core-shell structure was prepared by a combination of conjugate electrospinning and freeze-dry technology. The core fiber was poly(l -lactide-co-caprolactone) (PLCL)-based and the core fibers were coated with heparin/silk gel, which acted as a shell layer. This special structure in which the core layer was made of synthetic materials and the shell layer was made of natural materials took advantage of these two different materials. The core PLCL nanofibers provided mechanical support during vascular reconstruction, and the shell heparin/silk gel layer enhanced the biocompatibility of the grafts. Moreover, the release of heparin in the early stage after transplantation could regulate the microenvironment and inhibit the proliferation of intima. All of the graft materials were biodegradable and safe biomaterials, and the degradation of the graft provided space for the growth of regenerated tissue in the late stage of transplantation. Animal experiments showed that the graft remained unobstructed for more than eight months in vivo. In addition, the regenerated vascular tissue provided a similar function to that of autogenous vascular tissue when the graft was highly degraded. Thus, the proposed method produced a graft that could maintain long-term patency in vivo and remodel vascular tissue successfully. [ABSTRACT FROM AUTHOR]

Herein, we report a drug eluting scaffold composed of a composite nanofibers of poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) loaded with Hydroxyapatite nanoparticles (HANPs) and simvastatin (SIM) mimicking the bone extracellular matrix (ECM) to improve bone cell proliferation and regeneration process. Indeed, the addition of PGS results in a slight increase in the average fiber diameter compared to PCL. However, the presence of HANPs in the composite nanofibers induced a greater fiber diameter distribution, without significantly changing the average fiber diameter. The in vitro drug release result revealed that the sustained release of SIM from the composite nanofiber obeying the Korsemeyer–Peppas and Kpocha models revealing a non-Fickian diffusion mechanism and the release mechanism follows diffusion rather than polymer erosion. Biomineralization assessment of the nanofibers was carried out in simulated body fluid (SBF). SEM and EDS analysis confirmed nucleation of the hydroxyapatite layer on the surface of the composite nanofibers mimicking the natural apatite layer. Moreover, in vitro studies revealed that the PCL-PGS-HA displayed better cell proliferation and adhesion compared to the control sample, hence improving the regeneration process. This suggests that the fabricated PCL-PGS-HA could be a promising future scaffold for control drug delivery and bone tissue regeneration application. [ABSTRACT FROM AUTHOR]

• A novel composite nanofiber loaded with simvastatin and TiO 2 /PANI was developed by electrospinning method. • Wettability and drug release were adjusted with varied content of TiO 2 /PANI. • Drug release mechanism and kinetics were studied using different models. • Composite nanofibers provided potential platform for triggering the biomineralization process. • Highly biocompatible composite nanofibers improved MC3T3-E1 proliferation and adhesion. Poly(ε-caprolactone) (PCL) nanofibers loaded with polyaniline coated titanium oxide nanoparticles (TiO 2 /PANI) and simvastatin (SIM) drug were produced by the electrospinning method. As-prepared samples were investigated in terms of morphology characterization, mechanical properties, physiochemical properties, drug release, biomimetic mineralization, and biocompatibility. in vitro drug release studies were conducted in the phosphate buffer saline (PBS) at pH 7.4. The results suggest that varying the concentrations of TiO 2 /PANI nanoparticles could change the rate of drug release. The release mechanism was studied using several kinetic models, including the Higuchi model, the Hixson–Crowell model, and the Korsmeyer–Peppas model, to clarify the mechanism of SIM release from the composite nanofibers. The assessment of in vitro mineralization of the composite nanofibers for the growth of hydroxyapatite was performed in simulated body fluid (SBF). Field scanning electron microscopy (FE-SEM) imagery and energy-dispersive X-ray spectroscopy (EDS) analyses indicated that after soaking in SBF, a hydroxyapatite layer was formed on the surface of the nanofibrous webs. These novel composite nanofibers release simvastatin in a controlled manner with profound cell proliferation and attachment compared to that in pure PCL nanofiber, which indicates their potential for bone regeneration applications. [ABSTRACT FROM AUTHOR]