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The increasing popularity of wearable electronics has sparked interest in flexible energy harvesters as alternatives to conventional batteries. Flexible magnetoelectric (ME) composites, known for converting ambient magnetic field energy into useable power, are emerging as promising autonomous energy sources for integration into wearable devices. In this study, we prepared flexible (PVDF-AlN)–(NiO–CNF) based ME composites using two different methods: solution-casting and electrospinning techniques. The ME coupling was confirmed by measuring the ferroelectric and magnetic properties of the composite, and it was qualitatively characterized through the ME coupling coefficient. The electrospinning fibers-based ME composite exhibited an optimal value of 10.6 V/cm.Oe, significantly higher than the solution-casting films-based ME composite (1.3 V/cm.Oe) under a 1 kHz AC magnetic field (off-resonance condition). Subsequently, a flexible magneto-mechano-electric (MME) generator was designed using electrospun-derived material, harvesting a sinusoidal wave with a maximum output peak-to-peak voltage of 9.02 V. The generator displayed an optimal DC power density of 97 μW/m2 when exposed to a weak AC magnetic field of 6 Oe at a frequency of 50 Hz. Consequently, it holds great promise as an efficient autonomous power supply for medical sensing and various miniature electronic applications. [ABSTRACT FROM AUTHOR]

SiBCN ceramic materials are widely studied in electromagnetic wave (EMW) absorption. However, their practical application is limited due to the problem of poor impedance matching. In this study, SiBCN (Ni) fibers were successfully prepared by doping magnetic metal Ni, and the absorption properties of the samples were systematically investigated at different high-temperature treatments (1200 °C–1500 °C). The results showed that the doping of Ni contributed to the formation of carbon nanotubes (CNTs), which could enhance the improvement of conductive loss performance. Additionally, the catalytic effect of Ni promoted the formation of various crystals, including Ni 2 Si, β-SiC, Si 3 N 4 , and Si 2 N 2 O, resulting in the presence of multiple heterogeneous interfaces and excellent polarization loss capability. The Ni 2 Si particles acted as magnetic loss units, thereby enhancing the impedance matching of the fibers. Consequently, the SiBCN (Ni) sample prepared at 1300 °C exhibited a minimum reflection loss (RL min) of −21.38 dB and an effective absorption band (EAB) of 3.68 GHz. In addition, SiBCN (Ni) fibers coating proved effective in reducing Radar Cross Section (RCS) signals. Therefore, these findings suggest that SiBCN (Ni) fibers have the potential to serve as EMW absorbers in military radar and satellite communication. [Display omitted] [ABSTRACT FROM AUTHOR]

To address the challenge of poor fracture toughness of lithium disilicate glass-ceramics, which hinders their application as posterior single crowns and three-unit fixed bridges, the concept of fiber toughening was employed. In this study, Li 2 Si 2 O 5 fibers were successfully prepared through an electrospinning technology combined with sol-gel followed by a heat treatment. The fibers could be further densified by adding SiO 2 nano-powder to partially replace TEOS as a silicon source and the possible mechanism was put forward. By using the fibers as the reinforcement phase, the uniform fiber-toughened Li 2 Si 2 O 5 glass-ceramic composites were successfully produced by hot pressing sintering. These composites exhibited significant enhancements in mechanical properties, including a flexural strength of 315 ± 10 MPa, fracture toughness of 4.57 ± 0.35 MPa m1/2, and Vickers hardness of 5.61 ± 0.28 GPa, respectively. Notably, the highest fracture toughness of the composite increased by 41 % compared to the samples without fiber reinforcement, which was attributed to the toughening mechanisms including crack deflection, fiber bridging, and fiber pull-out. The results demonstrated the advantages of Li 2 Si 2 O 5 fibers in toughening glass-ceramic materials, thereby expanding the application areas of this material. [ABSTRACT FROM AUTHOR]

This paper reports a facile electrospinning method to synthesize aluminosilicate fibers by using aluminum chloride hexahydrate as single aluminum precursor, which contains no harmful or hazardous chemicals in the precursor sol. The results of Fourier transform infrared, X-ray diffraction, simultaneous thermogravimetry and differential scanning calorimetry show that the sols are diphasic. The thermal decomposition behavior, crystallization process and microstructure of the fibers are discussed in detail. The main components of aluminosilicate fibers heat-treated at 1200 °C are mullite (Al 6 Si 2 O 13), alumina (α-Al 2 O 3) and amorphous silica, while the alumina phase disappears when the molar ratio of Si to Al is below 1.5. The diameter and microstructure of fibers with different Si/Al molar ratios are obviously different, which is related to the large difference in conductivity of spinning sols. Bulk fibers and fibrous mats with good flexibility can be easily obtained by using alternative collectors. The tensile strength of the fibrous mats can reach 2.63 MPa and 1.52 MPa after heat-treated at 1000 °C and 1200 °C, respectively. The aluminosilicate fibers fabricated in this work has a noticeable potential in high temperature fields and related applications. [ABSTRACT FROM AUTHOR]

For electrospinning of MgO nanoparticle-based fiber architectures, we exploit the intermediate formation of layered Mg(OH) 2 nanosheets that form inside polyvinylalcohol (PVA) based fibers during nanoparticle-polymer formulation. Upon calcination, Mg(OH) 2 nanosheets undergo a topotactic dehydration reaction. In conjunction with polymer removal, these sheets generate staggered MgO nanoparticle ensembles that comprise flat ribbons. With methanol as a solvent and in polyvinylpyrrolidone (PVP) fibers, the MgO nanoparticles retain their crystallinity and structure inside the electrospun fibers. After calcination, they form nanoparticle threads with a cylindrical profile and particle size gradient. [ABSTRACT FROM AUTHOR]

SnO 2 material has good stability, electrical conductivity and high visible light transmittance, showing great potential in the field of stealth materials. However, it is an important research topic that how to improve its multispectral compatible stealth performance, meet the requirements of combat weapons against all-round attack, and conform to the development trend of "thin, light-weight, wide-band and high-performance" stealth materials. Therefore, Sn 0.84 Sm 0.08 Sb 0.08 O 2 micro/nano fibers material was prepared by coaxial electrospinning method combined with heat treatment process in this work. The material has a three-dimensional hollow porous fiber structure, and has a larger specific surface area and better compatible stealth performance than solid core fibers. The hollow porous Sn 0.84 Sm 0.08 Sb 0.08 O 2 micro/nano fibers material shows good absorbing ability in X-band. When the matching thickness is 2.6 mm, its effective absorbing bandwidth is 3.51 GHz, and when the matching thickness is 2.8 mm, its lowest reflection loss(RL) is −22.51 dB at 10.3 GHz. Secondly, it has a lower infrared emissivity in the infrared detector working bands of 3–5 μm and 8–14 μm, which are 0.558 and 0.672, respectively. Finally, it has reflectivity at the laser operating wavelengths of 1.06 μm and 1.55 μm, which are 7.9% and 2.1%, respectively. The material achieves the organic unity of high absorption in the radar band, low emissivity in the infrared band and low reflectivity at the laser wavelength. At the same time, this work explores the regulation mechanism of the hollow porous structure on electromagnetic wave absorption, infrared emissivity and laser reflectivity, which provides a certain reference for the development of single-type, light-weight, high-performance multispectral compatible stealth materials. [ABSTRACT FROM AUTHOR]

Ceramic fiber felts are attractive candidates for high temperature insulation due to their lightweight, high porosity and low thermal conductivity. In this work, ceramic felts constructed by γ-Y 2 Si 2 O 7 fibers were prepared by a facile method of Y–Si–O/PVB sol-gel electrospinning combined with subsequent high-temperature calcination. Effects of calcination temperature on the phase composition, microstructure and thermal insulation properties of ceramic felts were systematically studied. Results indicated that the organic components in the sol-gel fibers were removed after high temperature calcination, while the fibers kept the original continuous microtopography with high aspect ratios. Ceramic fiber felts of pure γ-Y 2 Si 2 O 7 phase could be obtained after calcinated at 1300 °C. The as-prepared paper-like γ-Y 2 Si 2 O 7 fiber felt presented low density of ∼120 mg/cm3 and a high porosity up to 97.03%. Combined with the inherent high temperature stability and low thermal conductivity of γ-Y 2 Si 2 O 7 , this light ceramic felts possessed high-temperature resistance and thermal insulating property (low thermal conductivity of 0.052 W m−1 K−1). The successful preparation of this ceramic fiber felt may provide a perspective for insulation materials used in harsh environments. [ABSTRACT FROM AUTHOR]

In order to expand the application prospects of SiCN ceramics in the field of microwave (MW) absorption materials, a series of Ni 3 Si embedded SiCN ceramic fibers composites (NSF) were prepared by controlling Ni conversion rate through the electrospinning technique and polymer derivation, with the intention of improving the impedance matching degree, enhancing the conductivity and polarization, and further promoting the dielectric loss ability and MW absorption performance of ceramic materials. The microstructure, phase composition, conductivity, MW absorption properties and mechanism of the material were analyzed by a variety of characterization methods. The results show that NSF exhibited high dielectric loss efficiency and desirable effective absorption bandwidth (EAB) when the conversion rate of Ni was 0.5 wt%: The MW of the entire Ku band (12–18 GHz, 6 GHz) could be effectively absorbed by the sample with a thickness of 2.64 mm, and its EAB could cover 6–18 GHz by adjusting its thickness from 1 mm to 5 mm, so its performance is significantly superior to a number of similar SiCN based composite ceramic materials previously reported. To sum up, the NSF prepared in this work exhibits suitable impedance matching degree, good conductivity, obvious polarization effect, excellent dielectric loss ability, and gratifying EAB in MW, and it is expected to become a powerful candidate in the field of broadband MW absorption materials in the future. [ABSTRACT FROM AUTHOR]

Aiming to offer a high-performance Co-free cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs), a series of La 0.8 Sr 0.2 Fe 1-x Cu x O 3-δ (LSFCux, x = 0.0–0.3) nanofiber cathodes were synthesized by the electrospinning method. The effects of various Cu doping amounts on the crystal structure, fiber morphology, and electrochemical performance of LSF nanofiber cathode materials were investigated. The results indicate that after being calcined at 800 °C for 2 h, the perovskite structure samples with a high degree of crystallinity are obtained. The morphology of electrospun nanofibers is continuous, and the average diameter of nanofibers is about 110 nm. In addition, the La 0.8 Sr 0.2 Fe 0.8 Cu 0.2 O 3-δ (LSFCu2) fiber cathode displays the optimal electrochemical performance, and the polarization resistance (R p) is 0.674 Ω cm2 at 650 °C. The doping of Cu transforms the main control step of the low-frequency band from dissociation of oxygen molecules to charge transfer on the electrode, and the maximum power density (P m) of the Ni-SDC/SDC/LSFCu2 single cell reaches 362 mW cm-2 at 650 °C. [ABSTRACT FROM AUTHOR]

Ceramic fibrous membranes have promising application in gas solid filtration and in areas requiring high thermal insulation, as well as catalyst supports, owing to their high porosity and low thermal conductivity. However, achieving flexible ceramic fibrous membranes that are stable at high temperatures remains a challenge. In the present work, a CaZrO 3 fibrous membrane with excellent stability at 1200 °C and good flexibility at 1100 °C was achieved using a combination of sol-gel and electrospinning methods. The thermal decomposition process and microstructure evolution of CaZrO 3 precursor fibers at high temperatures were discussed. The single orthorhombic phase of CaZrO 3 fibers was stable up to 1400 °C. Furthermore, the CaZrO 3 fibrous membrane exhibited excellent alkaline resistance. The excellent thermal stability and flexibility of the CaZrO 3 fibrous membrane make it a promising candidate for high-temperature applications. [ABSTRACT FROM AUTHOR]

Core-shell ceramics fibers with multiple composition are ideal candidates for thermal insulation application at high temperature. Herein, ultrathin C–SiC/ZrSi x O y C z core-shell fibers were successfully fabricated by coaxial electrospinning and high temperature pyrolysis with polycarbosilane (PCS) as core precursor and Zirconium butoxide as shell precursor, respectively. The ceramics fibers revealed distinct core-shell partition. The average diameter was about 3 μm and the shell thickness increased to 500 nm with increasing pyrolysis temperature. Thermogravimetry analysis (TGA) results showed that the weight of the fibers reduced to 60% in Ar atmosphere and rose to 108% in O 2 atmosphere, which confirmed the excellent thermal stability and anti-oxidation properties due to the protection effect of shell layer and the self-healing mechanism. Moreover, the ceramics fibers maintained good flexibility and deformability. Such optimized anti-oxidation and mechanical performance indicates that the prepared core-shell fibers could be an excellent thermal insulation material for high temperature application. [ABSTRACT FROM AUTHOR]

In this work, ZrB 2 –ZrC–SiC composite nanofibers were prepared by electrospinning combined with the carbothermal reduction method. The morphology, phase composition, and oxidation resistance of the composite nanofibers were investigated. The results showed that ZrB 2 –ZrC–SiC composite nanofibers with good crystallinity were obtained after calcination at 1550 °C. The obtained fibers distributed uniformly, and the average diameter was about 375 nm. ZrB 2 –ZrC–SiC nanofibers were oxidized at 587 °C, which was higher than that of the ZrB 2 –ZrC nanofibers. It revealed that the addition of SiC could improve the oxidation resistance of ZrB 2 –ZrC composite nanofibers. [ABSTRACT FROM AUTHOR]

Hafnium oxide (HfO 2) fibers can be widely used in ultra-high temperature ceramics (UHTCs) as reinforced material in order to achieve better antioxidant performance and less cracks and flaking on surface of UHTCs in field of ultra-high temperature thermal protectors. Calcination temperature is one of essential parameters for forming HfO 2 fiber. In this work, one-dimensional (HfO 2) fibers were prepared through the electrospinning method and further post-calcination treatment. During the calcination treatment, the monoclinic-HfO2 (m-HfO 2) was formed from as-spun HfO 2 fibers at 432 °C, and only a small amount of m-HfO 2 was converted into the tetragonal HfO 2 at 1013 °C, which can increase the fiber density and decrease the grain size. However, the remaining m-HfO 2 was directly converted into the cubic HfO 2 at 1351 °C. The unique temperatures of forming monoclinic, tetragonal, cubic phase were much lower than the phase-transition temperature. The prepared HfO 2 fiber could still maintain fibrous morphology after 10 times cyclic thermal shock in air. Moreover, the fibers calcined at 900 °C and 1200 °C have better thermal shock resistance for their stable phase and fibrous morphology with uniform grain growth after the thermal shock test. [ABSTRACT FROM AUTHOR]

Flexible microwave absorbers with high stability are in increasing demand for the applications under harsh conditions. SiC as a functional ceramic material has the feature of high environmental tolerance and adjustable electromagnetic (EM) absorbing properties, making them suitable to be applied for harsh environments. However, the electrical property of SiC requires to be further enhanced to obtain qualified EM absorbing performance. In this work, multiwall carbon nanotubes (CNTs) were introduced to SiC to enhance the electrical properties. Flexible two-dimensional (2D) CNTs loaded SiC fiber mats were prepared as EM absorbers via electrospinning and polymer-derived-ceramic (PDC) methods. The CNTs inside the fibers can form conductive networks and act as reinforcement to ensure high flexibility and enhance the microwave absorption properties of SiC mats. Thus, a reflection loss of −61 dB and an effective absorption band (EAB) of 2.9 GHz were obtained. More importantly, the EM absorption can be adjusted by tuning the content of CNTs and the EAB can cover the entire X-band by adjusting the material thickness. The work provided a facile strategy to fabricated flexible 2D ceramic mats with high environmental stability and tunable electrical properties, which may shed light on the production of reliable EM absorber for broadband EM absorption applications. [ABSTRACT FROM AUTHOR]

Titanium carbide (TiC) fibers are attractive functional materials that find application in the areas of energy, environment, and biology. Herein, a simple precursor route is designed to prepare TiC fibers by means of electrospinning. The precursor is prepared by adding polyvinylpyrrolidone (PVP) to as-synthesized polytitanoxane (PTO), and the synthesis process, structure, and thermal behavior of the resulting TiC fibers are analyzed. Smooth and continuous precursor fibers with a uniform diameter of ~1.22 μm are obtained after the electrospinning of the precursor. With increase in the preparation temperature, the phase composition of the fibers evolves into TiC from TiC x O y via pyrolysis and carbothermal reduction. Chemical-state analysis results show that the surface of as-prepared TiC fibers exhibits very weak oxidation, thus leading to TiO 2 and TiC x O y formation. In addition, all the prepared fibers show uniform morphologies without adhesion. With the proposed approach, continuous TiC fibers with a diameter of ~0.55 μm can be obtained. [ABSTRACT FROM AUTHOR]

The growth of one-dimensional nanostructured semiconductors with aligned configuration and tunable aspect rations is recognized as one of the critically important and fundamental issues, for exploring polarized light sources as the back lights in liquid crystal display (LCD) with desired optical performance. In the present work, aiming to endow the perovskite nanocrystals (NCs) with enhanced stability and polarized optical performance, we reported the in situ growth of aligned CsPbBr 3 nanorods in polystyrene (PS) fibers, which was based on a facile one-step electrospinning technique. It was found that the electrospinning temperatures could have a profound effect on the growth of CsPbBr 3 nanorods with various aspect ratios (ARs), enabling their growth in a tailored manner. The mechanism on the tunable growth of aligned CsPbBr 3 nanorods in PS fibers was proposed. We reported the in situ growth of aligned CsPbBr 3 nanorods with tunable aspect ratios in PS nanofibers by a facile one-step electrospinning approach, which might be of particular interest to be used as polarized light sources in liquid crystal displays. Image 1 [ABSTRACT FROM AUTHOR]

In the present work, Ba 1-x Sr x MnO 3 (x = 0.03, 0.07, and 0.10) fibers are synthesized by using the electrospinning–calcinations combinations process. The fabricated fibers were characterized by a combination of analytical technique such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive analysis of X-rays (EDAX), Fourier Transform Infrared (FT-IR), and Diffuse reflectance spectroscopy (DRS). XRD confirms hexagonal structure of Ba 1-x Sr x MnO 3 fibers. A classical size-strain plot (SSP) method has been applied to estimate the microstructure parameters of the produced fibers from the XRD peak broadening analysis. SEM images show the randomly oriented fibers along with diameter growth upon increasing the Sr content. DRS technique was used to estimate the optical band gap of the synthesized samples. The gas sensing study shows the sensing ability of Ba 1-x Sr x MnO 3 fibers, pressed into pellets, toward ethanol vapors. [ABSTRACT FROM AUTHOR]

In this work, cement-free alumina castables with different fiber additives were produced. The effect of commercial polypropylene fibers was compared to that of magnesium borate precursor fibers produced by electrospinning. The drying behavior of different batches was monitored by means of thermogravimetry. Elastic moduli were estimated in dried, sintered and thermally-shocked samples through the impulse excitation technique. The mechanical strength as cold modulus of rupture (CMOR) was measured by three-point bending tests. The open porosity and bulk density after sintering were assessed by water immersion. The thermal shock resistance was evaluated by heating the samples up to 950 ∘C and then quenching with compressed air. After 1 or 5 thermal shock cycles, the residual CMOR was determined. The microstructure of fracture surfaces was analyzed by scanning electron microscopy (SEM). The possible formation of new phases during thermal treatment was also assessed by means of XRD. Finally, the refractoriness under load was measured. [ABSTRACT FROM AUTHOR]

The SiCN fibers were synthesized by the combination of polymer-derived method and electrospinning technology. The XRD, FT-IR, TEM, SEM, XPS and Raman spectroscopy were applied to study the phase composition, chemical structure, morphology and carbon crystalline state of the SiCN fibers. In addition, a vector network analyzer was used to study the electromagnetic properties of SiCN fibers. The results showed the amorphous carbon increased with the temperature increasing, which can significantly adjust the dielectric properties of the SiCN fibers. The SiCN fibers synthesized at 1300 °C showed excellent electromagnetic wave (EMW) absorption performance, wherein the effective absorption bandwidth was 4.59 GHz (11.8~16.4 GHz, RL < -10 dB) and the RL min value reached −31.1 dB at the thickness of 2 mm. [ABSTRACT FROM AUTHOR]

The high-temperature stability of the SiC ultrafine fibers is limited by the massive amounts of oxygen introduced during the oxidative curing process. In this study, vinyl-modified polycarbosilane (Vi-PCS) was synthesized through the hydrosilylation reaction of PCS and divinyldimethylsilane at 320 °C. The electrospun ultrafine Vi-PCS fibers were cured by heating to 320 °C in an inert atmosphere, initiating a subsequent hydrosilylation reaction. Subsequent pyrolysis at 1200 °C yielded SiC ultrafine fibers with uniform diameters (1.6–2.5 μm) and low oxygen content (4.64 wt%). The fibers retained their smooth surface morphology and flexibility up to 1700 °C due to the significant reduction of the SiC x O y phase. The resulting SiC ultrafine fibrous mats are promising materials for applications in harsh environments because of their high-temperature stability and low preparation cost. [ABSTRACT FROM AUTHOR]

Ceramic coatings have been widely used in industrial fields. K 2 Ti 6 O 13 fibers could be a potential coating material for low thermal conductivity, high mechanical strength and infrared reflectivity. The precursor fibers, using potassium acetate (CH 3 COOK) and tetrabutyl titanate (TBOT) as potassium and titanium sources, were prepared by the electrospinning technique with the sol-gel method. To prepare K 2 Ti 6 O 13 fibers, the mole ratio of K/Ti was adjusted from 1:2 to 1:3. The transformation of other phases of potassium titanates was characterized by XRD patterns and Raman spectra. The effects of mole ratio of K/Ti on morphology of samples have been investigated. Well-crystallized fibers were prepared with single-crystal K 2 Ti 6 O 13 structure. The corresponding morphology and microstructure evolution were studied by SEM and TEM. The as-obtained K 2 Ti 6 O 13 fibers possessed the high near-infrared (NIR) reflectivity of 98%. [ABSTRACT FROM AUTHOR]

CaZrO 3 (CZO) precursor fibers were prepared by sol-gel method and electrospinning technique from solutions which contained aqueous precursors of calcium and zirconium ions and polyethylene oxide. The crystallization of CZO fibers was a concurrent process with the decomposition of organics. The evolution process was characterized by Fourier transform infrared (FT-IR) and Raman spectra, thermogravimetry and differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The heat-conducting property and high temperature stability of fibers were characterized by the measurements of thermal conductivity and heating permanent linear change, respectively. The fibers were treated in NaOH solution at 80 °C to characterize the alkali resistance. The results showed that CZO fibers had the lower thermal conductivity than the other reported forms of CZO materials, and they possessed excellent stability up to 1100 °C with thermal shrinkage less than 1.2% and excellent corrosion resistance to alkalis. Hence, CZO fiber could be used as a suitable corrosion resistant refractory material for high-temperature thermal insulation. [ABSTRACT FROM AUTHOR]

Mullite nanofibers with small diameter and high surface area are an ideal candidate as the reinforcements in composite materials, and have promising applications in the fields of catalysis, filtration, thermal storage and so forth. In this work, electrospun mullite nanofibers were successfully synthesized using a hybrid mullite sol. The morphology and microstructure of fibers calcined at different temperatures were investigated. The morphology of fibers synthesized at 900 °C is porous with coarse surface, and after crystallization it becomes compact with smooth surface. The densities of fibers increase with the increasing temperatures. At 1200 °C the surface of fibers becomes coarse again, as a result of the grain growth of mullite. The crystallization path of fibers was revealed that the Al-rich mullite (4Al 2 O 3 ·SiO 2 ) together with amorphous silica formed at 1000 °C, changed into mullite with higher silica contents as temperature further increased, and finally transformed into a stable 3Al 2 O 3 ·2SiO 2 phase at 1200 °C. During this crystallization process, the flow of amorphous silica phase and the formation of mullite crystal structure benefit the densification of fibers, leading to the resultant fibers with fine and compact microstructure. The present findings can provide a guideline for the preparation of the promising high-mechanical mullite nanofibers and the synthesized nanofibers display great potential as reinforcements in structural ceramic composites. [ABSTRACT FROM AUTHOR]

In this paper, SiO 2 -TiO 2 hybrid fibres are fabricated using the electrospinning technique and Eu 3+ is successfully doped into the fibres through a simple sol-gel approach. The obtained SiO 2 -TiO 2 hybrid fibres are subjected to heat treatments at 600 °C, 800 °C and 1200 °C. The silica fibres subjected to a high temperature of 1200 °C become brittle and easily broken. Furthermore, the X-ray diffraction patterns demonstrate that crystalline titania forms in the SiO 2 -TiO 2 samples treated at 1200 °C, and excellent flexibility is demonstrated in the corresponding SiO 2 -TiO 2 non-woven mat. Moreover, the stress-strain curve demonstrates that the SiO 2 -TiO 2 mat heat-treated at 1200 °C exhibits typical elastic-plastic behaviour. Finally, the emission intensity of Eu 3+ of the SiO 2 -TiO 2 fibres is higher than that of the analogous SiO 2 fibres. This method can be adapted to fabricate inorganic-based hybrid fibres and will pave the way for the implementation of SiO 2 -TiO 2 non-woven mats in related research fields. [ABSTRACT FROM AUTHOR]

In this paper, flexible mesoporous Si-doped Al 2 O 3 ultrafine fibers were successfully prepared by electro-blow spinning (EBS) technology followed by a calcination process. The effects of spinning parameters, including air pressure, voltage, and solution injection rate on the morphology and diameter of fibers were investigated. The results showed that the spinning parameters played a key role on determining the morphology and diameter of fibers, and the specific surface area of fibers significantly increased with the increasing content of pore forming agents (polytetrafluoroethylene, PTFE), at the same time the pore size distribution was mainly concentrated at ~5 nm. Most importantly, Si(OC 2 H 5 ) 4 was introduced to act as the flexible regulator which could inhibit the growth of alumina crystal, decrease the crystal size, and thus the flexibility of obtained mesoporous Si-doped Al 2 O 3 ultrafine fibers can be improved. Moreover, the fibers productivity by EBS method was higher than that of traditional electro-spinning. In the future, the mesoporous Si-doped Al 2 O 3 ultrafine fibers may perform desired function and spread their applications in different areas. [ABSTRACT FROM AUTHOR]

A uniaxially-aligned nanofibrous matrix was produced by electrospinning and it demonstrates strong piezoelectric property. The matrix is composed of highly-aligned polyvinylidene fluoride (PVDF) polymer nanofibers embedded with barium titanate (BaTiO 3 ) nanoparticles. Measurements of piezoelectrically generated voltages in response to mechanical deformation of BaTiO 3 –PVDF composite nanofibers with various concentrations of BaTiO 3 nanoparticles showed that the magnitude of the resultant voltage increases as the nanoparticle concentration increases. PVDF nanofibers with 16 wt% BaTiO 3 nanoparticles exhibit piezoelectric output voltages that are 1.7 times greater than PVDF fibers without BaTiO 3 nanoparticles when subjected to the same degree of deformation. Scanning electron microscopy confirmed the uniaxial alignment of PVDF nanofibers with individual fiber diameters of ~200 nm as well as the presence of BaTiO 3 deposits. The increased piezoelectric response of uniaxially-aligned BaTiO 3 –PVDF nanofibers in comparison with randomly oriented PVDF fibers and thin films suggests possible uses for such nanofibers in energy harvesting and as power sources in miniaturized electronic devices like wearable smart textiles and implantable biosensors. [ABSTRACT FROM AUTHOR]

Fibrous scaffolds have gained increasing attention in tissue engineering applications because of their high porosity, and surface area. In the current study cerium or gallium- containing silicate based 13-93 bioactive glass fibers were prepared using electrospinning approach. Effect of cerium and gallium substitution (up to 5 w%) on the in vitro bioactivity, pre-osteoblast cell response and antibacterial activity of the prepared fibers were assessed. Results revealed that, addition of cerium or gallium has no negative effect on bioactivity and hydroxyapatite forming ability of the glass in long term. The biocompatibility tests on MC3T3-E1 cells using XTT assay revealed no cytotoxicity of the cerium- or gallium-containing bioactive glass fibers. The fibers prepared in the study showed no antibacterial response to the gram positive ( Staphylococcus aureus ) and gram negative ( Escherichia coli ) bacteria. Fibrous scaffolds manufactured in the study may be considered for the use in soft tissue engineering applications in near future. [ABSTRACT FROM AUTHOR]

Three dimensional porous random Mn 2 O 3 and Mn 3 O 4 nanofibers were successfully prepared via a facile electrospinning homogenous solution of 0.006 mol of manganese nitrate 4-hydrate in 10 wt% polyvinyl alcohol followed by calcination of the as-spun nanofibers at 500, 700 and 1000 °C. The processing parameters that directly influence the morphology of the produced fibers are namely; concentration, viscosity of the solution as well as the potential of spinning as high concentration gave beaded fibers at all applied potentials. The present selected conditions were found to be; voltage 24 kV, flow rate 0.3 ml/h, the distance between the needle and collector 10 cm, viscosity 0.955 Pa S and the inner diameter of the needle 0.39 mm. X-ray diffraction results of the nanofibers showed that Mn 2 O 3 and Mn 3 O 4 phases were processed at two temperature; 700 °C and 1000 °C, respectively. Field emission scanning electron microscopy revealed that Mn 2 O 3 and Mn 3 O 4 nanofibers were fabricated with diameters in the range of 40–80 nm and 70–300 nm, respectively. [ABSTRACT FROM AUTHOR]

Bioactive glasses are widely used in biomedical applications due to their ability to bond to bone and even to soft tissues. In this study, 45S5 bioactive glass fibers were prepared through sol–gel processing and electrospinning technique. A precursor solution containing poly vinyl alcohol and bioactive glass sol was used to produce fibers. The mixture was electrospun at a voltage of 20 kV by maintaining tip to a collector distance of 8 cm. The fibers with an average diameter of 337±81 nm (before calcination) were successfully obtained. Results showed that the crystalline phase of the fibers was largely influenced by the calcination temperature. Hydroxyapatite formation on calcined 45S5 fibers was investigated in simulated body fluid (SBF) using different fiber/SBF (F/S) ratios (0.5, 1, 2 and 10 mg/ml) at 37 °C. When immersed in SBF, conversion to a calcium phosphate material showed a strong dependence on the F/S ratio. At high solid concentration (10 mg/ml), surface of the fibers could not be converted to the HA-like material in SBF after 30 days. At lower solid concentrations (2, 1 and 0.5 mg/ml) an amorphous calcium phosphate layer formation was observed followed by the conversion to hydroxyapatite. [ABSTRACT FROM AUTHOR]

Abstract: Cerium-doped lutetium oxyorthosilicate (Lu2SiO5:Ce3+, or shortly LSO:Ce) luminescent ceramic fibers were synthesized by the sol–gel process followed with electrospinning in the present research. Polyvinyl butyral (PVB) was used as a spinnable carrier and anhydrous system availed the efficient generation of the composite fibers. The phase of Lu2SiO5 starts to appear at 1100°C based on XRD analysis. After annealed at 1200°C for 4h, all samples with different cerium doping concentrations show a pure phase of LSO with a well-crystallized structure. The annealed samples retain smooth surfaces and uniform morphologies. LSO:Ce fibers thus prepared exhibit a strong emission peak located at about 403nm, corresponding to the Ce3+ 5d1→4f1 transitions. LSO:1%Ce fibers exhibit the most intense emission among the samples doped with different cerium concentrations, which also present a much stronger emission than that of LSO:1%Ce powders. X-ray excited luminescence (XEL) spectrum shows that LSO:Ce fibers present a considerable scintillation property as well. Short decay time trait was also observed in LSO:Ce fibers due to their microscopic defects at grain boundaries and surfaces. [Copyright &y& Elsevier]

Abstract: Flexible ceramic nanofibers have been electrospun from a novel TiO2–SiO2 aqueous sol. The nanofibers obtained have an average diameter of around 150nm and are amorphous even after heat treatment at 600°C for 3h in air. Since the material is amorphous it may be considered as electrospun glass nanofiber. Fracture in glass usually initiates from surface defects and in the absence of any preferred plane propagates perpendicular to the surface. The presence of surface defects on the heat treated nanofibers could not be detected on SEM and TEM images. It is hypothesized that the observed flexibility is due to significant reduction in surface defects. [Copyright &y& Elsevier]

Abstract: Ultra-fine Al2O3 fibers were synthesized via electrospinning technique using PVP/ethanol polymer solution and aluminium acetate sol followed by calcinations at higher temperature. The formation, crystalline phase, surface morphology, fibers diameter and surface area of alumina ultra-fine fibers were characterized using FT-IR, TGA/DTA, XRD, SEM, TEM and BET analytical techniques. The results show that pure and crystalline α-Al2O3 ultra-fine fibers were formed with fiber diameter in the range of 100–500nm and BET surface area of the fibers were found to be 40m2/g. [Copyright &y& Elsevier]