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Acoustic energy harvesting (AEH) by a nanostructured membrane has recently gained increasing attention. This study focused on a novel approach for in-situ crystallization of Pb(Zr 0.58 Ti 0.42)O 3 (PZT) as a piezoelectric nanogenerator (PENG) inside the carbon fibrous membranes (CFM). The electrospinning process and post-heat treatment were applied to synthesize the CFM-embedded PENG, which benefits from both the flexibility of carbon fibers and the piezoelectric properties of the crystallized PZT. The results indicated that the carbon fibers kept their microstructure over the heat treatment at 250 and 350 °C while the crystallization fraction of PZT increased. The XPS analysis revealed that the CFM embedded by in-situ crystallized PENG had a higher diversity of tetragonal and rhombohedral in comparison with the CFM embedded by the pre-crystallized PENGs. Furthermore, the electrical conductivity, dielectric constant, and ferromagnetic properties of CFM were improved with the incorporation of the in-situ crystallized PENGs. The acoustic studies in the range of 250–2000 Hz under sound pressure of 90 dB revealed that sound absorption performance of CFM was increased by about +35 %. Also, the ability of CFM in the AEH process was enhanced drastically by embedding the PENGs inside the carbon fibers. The maximum harvested electricity at 500 Hz was 5.9 and 13.9 W m−2 by CFM embedded by in-situ crystallized and pre-crystallized PENGs, respectively. The above results exhibit the great potential for the CFM-embedded PENGs to be used in low-frequency AEH applications. [ABSTRACT FROM AUTHOR]

As the research for advanced materials suitable for high-temperature uses continues, the need for oxide ceramic micro-nanofibers with outstanding mechanical and thermal properties becomes increasingly important. By incorporating two types of magnesium sources, specifically Mg(CH 3 COO) 2 ·4H 2 O and MgCl 2 ·6H 2 O, into the precursor, a range of fibers made of magnesium silicate ceramics was produced through electrospinning. X-ray diffraction (XRD) analysis verified that the resulting multiple phases included MgO, MgSiO 3 , Mg 2 SiO 4 , and amorphous SiO 2 , with the phase composition being affected by the diffusion reaction of Mg ions. The fibers produced using the dual-precursor method maintained a stable morphology with a uniform and compact structure after undergoing high-temperature treatments ranging from 1000 to 1200 °C. This study is the first to report the tensile strength of magnesium silicate fibrous membranes, which was found to be 1.54 ± 0.27 MPa and 1.21 ± 0.73 MPa after heat treatment at 800 °C and 1000 °C, respectively. Furthermore, these fibrous membranes demonstrated dependable thermal insulation properties within the testing range of 500–1000 °C, along with a low thermal conductivity at room temperature of 0.0301–0.0306 W m−1·K−1. Characterized by their impressive mechanical strength and high temperature stability, magnesium silicate ceramic micro-nanofibers show significant potential for various applications in the targeted field. [ABSTRACT FROM AUTHOR]

Oxide nanofibers are widely used in several applications, including thermal insulation, fuel cells, flexible sensors, and catalyst support. Fiber morphology significantly affects their application performance. In this work, alumina-based nanofibers were successfully prepared using a sol-gel combined with an electrospinning method. The electrostatic polarity effects on fiber morphology were investigated. When fibers were electrospun by negative polarity at elevated voltages, the fibers retained uniform and smooth morphology, with a slightly increased average diameter and diameter uniformity. In contrast, ultra-thin nanofibers were generated when electrospinning was done under positive polarity. The strong charge repulsion by the agminated cations in the precursor caused bifurcations, finally forming ultra-thin nanofibers. At increased voltages, the electrospun fibers with positive polarity exhibited a distinctly increased average diameter and decreased diameter uniformity. This was attributed to the increased fiber whip scope, increasingly robust nonaxisymmetric whip behaviors, and fiber bifurcation during the jet whipping process. The results showed that the electrostatic polarities can affect the morphology of oxide fibers. This study provides guidance to prepare oxide nanofibers with desired morphology and specific requirements. [ABSTRACT FROM AUTHOR]

Tackling large bone defects remains a significant clinical challenge due to the limitations in current treatment strategies. This study presents a modular tissue-engineered bone, achieving rapid vascularization within 14 days and showing significant initial stability after implantation. This innovation is driven by the synergy of high-resolution mono-LCD mask photopolymerization 3D printing, electrospinning technology, and photosensitive gel cell carriers, resulting in a bioceramic-electrospun fiber composite scaffold (BECS) that enhances nutrient permeation and mechanical support. Emphasizing biomimicry, the scaffold incorporates an electrospun ultrafine fiber membrane that simulates the periosteum's microvascular structure, crucial for rapid endothelialization of graft lumens. This membrane acts as an advanced carrier for vascular endothelial growth factor (VEGF), facilitating targeted release that significantly promotes vascular regeneration. Our in vitro and in vivo analyses indicate that immediate vascularization and subsequent osteogenesis significantly enhance blood supply and bone regeneration in defect sites. Notably, the application of Human umbilical cord mesenchymal stem cells (UC-MSCs) within the gelatin methacrylate (GelMA) cell carrier ensures uniform distribution and proliferation, essential for balanced bone regeneration. Demonstrating a 75% increase in vascular network formation and a 60% enhancement in osteocalcin (OCN) expression within the initial four weeks, the scaffold supports both rapid vascularization and osteogenesis. This dual-functional tissue-engineered bone represents a significant advancement for treating large bone defects, with the potential to improve current therapeutic strategies substantially. [ABSTRACT FROM AUTHOR]

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]

With the advancement of wireless communication and electronic equipment, microwave absorption materials (MAMs) have more and more broad applications in related fields. Ti 3 C 2 T x -MXene with unique two-dimensional structure and excellent dielectric properties is often used as a precursor of nano-TiO 2 , which is a potential MAMs. Carbon nanofibers, as a one-dimensional material, have great electrical conductivity and can form interconnected three-dimensional conductive networks. In this study, Ti 3 C 2 T x -MXene was prepared by in-situ HF etching method, and further combined with the benefits of Co, Ce metals, and carbon nanofibers. Co/CeO 2 /TiO 2 /CNFs were prepared via a facile technique for electromagnetic microwave (EM) absorption, exhibiting excellent EM absorption performance due to the synergistic effects of dielectric and magnetic properties. The minimum reflection loss (RL min) and effective absorption bandwidth (EAB) reache −63.35 dB (11.2 GHz) and 3.6 GHz (9.5–13.1 GHz), with a thickness of only 2.35 mm and a filling rate of 30 wt%, while the maximum EAB reaches 5.4 GHz (12.4–17.8 GHz) with a thickness of 1.82 mm, covering nearly the entire Ku band. By offering a novel strategy to the creation of brand-new, high-performance MAMs based on 1D carbon nanofibers with dielectric/magnetic synergy, this work is believed to support the development of upcoming MAMs. [ABSTRACT FROM AUTHOR]

Flexible electronic components such as wearable sensors, energy harvesting devices, and human health monitoring systems based on piezoelectric materials have garnered significant attention within the scientific community. In this study, PZT nanofibers were modified with dopamine hydrochloride prior to their integration into PVDF fibers, serving as piezoelectric reinforcements to enhance the mechanical and piezoelectric characteristics of composite fiber films. Subsequently, a facile hot-pressing method was employed to fabricate multilayered films characterized by a densely packed surface fiber arrangement and a loosely organized internal fiber orientation, which markedly improved the self-supporting ability and fiber density of the electrospun fiber films. A detailed investigation into the micro-morphology, crystallinity, and enhanced piezoelectric properties of the films was conducted. Notably, the composite fiber film containing 6 wt% PZT NFs exhibited a peak piezoelectric coefficient (d 33) of 29 pC/N, resulting in an output voltage of 13.8 V. This represents a 2.23-fold enhancement in d 33 value and a 4.6-fold increase in output voltage when compared to the pristine PVDF fiber film, which had a d 33 of 13 pC/N and an output voltage of 3 V. The power density achieved by the sensor is 0.73 μW/cm2. This performance is underpinned by a high piezoelectric coefficient, outstanding output characteristics, and robust stability, which collectively enhance the sensor's efficacy in various applications. This research presents an effective approach for augmenting the piezoelectric performance of PVDF-based composite films and paves the way for the advancement of piezoelectric energy harvesting applications. [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]

With the miniaturization and integration of modern high-power electronic devices, heat accumulation has become a key issue affecting their performance and reliability, which puts forward higher requirements for the thermal conductivity of polymer materials. In this study, boron nitride (h-BN) was dispersed into silica sol, and high aspect ratio core-shell fillers (h-BN@SiO 2) were prepared by electrospinning. Then h-BN@SiO 2 /epoxy resin (EP) composites were prepared by hot pressing. Owing to the macroscopic and microscopic "double network" conduction paths constructed by h-BN@SiO 2 fillers, the in-plane thermal conductivity (λ ||) of h-BN@SiO 2 -Ⅲ/EP composites is 6.719 Wm−1K−1, which is 27 times that of EP, and the out-of-plane thermal conductivity (λ ⊥) is 0.698 Wm−1K−1, which is 4 times that of EP. The simulation and the classical thermal conductivity model verify that the new designed filler in this paper has advantages over the traditional filler in terms of heat transfer. More importantly, the prepared composites also maintain excellent electrical insulation and dielectric properties, which provides a new idea for the preparation of high thermal conductivity electrical insulation composites. [ABSTRACT FROM AUTHOR]

In this study, an electrospinning method was used to produce highly conductive freestanding carbon nanofibers (CNFs). The freestanding CNFs are compatible with hierarchical growth techniques, such as hydrothermal processes, for the nanostructure engineering of supercapacitor electrodes with enhanced electrochemically active sites. Therefore, the flower-like FeMoO 4 @CNF nanosheets were investigated to improve the electrochemical performance using aqueous and neutral electrolytes (Na 2 SO 4 and K 2 SO 4). The optimized FeMoO 4 @CNF electrode exhibits areal capacitances of 252 and 220 mF·cm−2 at a high current density of 2.5 mA·cm−2 with Na 2 SO 4 and K 2 SO 4 electrolytes, respectively. The wide potential window (1.6 V) of the symmetric supercapacitor delivered maximum energy densities of 22.4 and 19.6 μWh·cm−2 at a power density of 2 mW·cm−2 for Na 2 SO 4 and K 2 SO 4 electrolytes, respectively. [ABSTRACT FROM AUTHOR]

Among the family of high-quality fiber materials, mullite fiber membrane is a promising one that possesses abilities of both the thermal resistance and oxidation resistance under high temperature. High-purity mullite nanofibrous membranes were prepared by electrospinning method with low-cost aluminum chloride hexahydrate (AC) as the aluminum source. The effects of sintering temperature and AC content on the phase structure, microstructure, thermal and mechanical properties of the mullite nanofibrous membranes were investigated. The results show that the sintering temperature as low as 1000 °C is the very appropriate temperature for obtaining the high-purity mullite nanofibers with smooth surface. The minimum thermal conductivity of 0.029 W m−1 K−1 and maximum tensile strength of 6.11 MPa are gained from the mullite nanofibrous membranes with AC content of 2 mmol. The mullite nanofibrous membranes with excellent properties can be selected as an ideal candidate for thermal insulation and reinforced applications. [ABSTRACT FROM AUTHOR]

Developing multifunctional nanomaterials through the design and construction of advanced nanostructures that are highly compatible with various substances is a crucial approach. In this work, special-shaped Janus nanobelt with both up-conversion luminescence (UCL) and magnetism is firstly designed and fabricated via a conjugate electrospinning coupled with a di-crucible fluorination. [YF 3 : Yb3+, Ho3+@SiO 2 ] belt-in-belt nanobelt//CoFe 2 O 4 nanobelt conjugate electrospinning-constructed special-shaped Janus nanobelt (shorted as C-SJNB) was designed and successfully prepared for a case study. C-SJNB is composed of two mutually independent micro-zones, which are YF 3 : Yb3+, Ho3+@SiO 2 belt-in-belt nanobelt (BNB) called as luminescent micro-zone, and CoFe 2 O 4 magnetic nanobelt acted as magnetic micro-zone. In the C-SJNB structure, the design ensures that the luminescent substance does not directly contact with the magnetic substance, thereby reducing the adverse effects of the dark-brown magnetic CoFe 2 O 4 on the luminescent performance. C-SJNBs with structural advantages exhibit 7 times the UCL intensity compared to counterpart luminescent-magnetic YF 3 : Yb3+, Ho3+/SiO 2 /CoFe 2 O 4 hybrid nanobelts (HNBs) prepared by uniaxial electrospinning. Further, compared with [YF 3 : Yb3+, Ho3+@SiO 2 ]//CoFe 2 O 4 parallel electrospinning-constructed special-shaped Janus nanobelt (shorted as P-SJNB), C-SJNB possesses a higher quality of micro-morphology, and avoids the degradation of luminescence performance caused by the mixing of magnetic and luminescent substances at the interface. The UCL intensity and magnetism of C-SJNBs can be adjusted by changing the content of CoFe 2 O 4. When the CoFe 2 O 4 content increases from 0.5 mmol to 4 mmol, the saturation magnetization of C-SJNBs increases from 4.42 to 13.94 emu·g−1. The newly established technology eliminates the needs for complex electrospinning and post-processing procedures. The formation mechanism of C-SJNBs has been established, providing technical support for synthesizing other Janus nanobelts with a belt-in-belt structure on one side. These advanced Janus nanobelts are ideal for developing poly-functional nanomaterials and have important applications in dual-mode imaging, display devices, batteries, drug loading and delivery. [Display omitted] • A brand-new belt-in-belt nanobelt//nanobelt shaped Janus nanobelt is advanced. • Janus nanobelt is made by conjugate electrospinning with di-crucible fluorination. • Partition of four independent domains in Janus nanobelt is microscopically realized. • Conjugate electrospinning is better to prepare Janus nanobelts than parallel one. • Janus nanobelts have tuned magnetism and enhanced green upconversion fluorescence. [ABSTRACT FROM AUTHOR]

In this work, a 1D/2D two-phase structure of ZnO single-crystal nanosheets/ZnO–SnO 2 nanorods was constructed, and the hydrogen gas sensing properties including selectivity have been enhanced by this low-cost way without noble metal doping. It was proved that hydrogenation effect on ZnO (0001) single crystal facets was the key to forming the low resistance surface in hydrogen gas, leading significantly enhancement in response and selectivity. The response (R a /R g) to 200 ppm hydrogen gas exceeded 400 at a low operating temperature of 150 °C, response/recovery time in 100 ppm H 2 was only 30 s/8 s. The sensor also has good selectivity for hydrogen detection. The enhancement in gas sensing properties due to dual mechanism of the hydrogenated low-resistance surface and the resistance modulation of ZnO/SnO 2 heterojunctions, which proposed in this paper. [ABSTRACT FROM AUTHOR]

The increasing global energy consumption and carbon emissions propelled the demand for materials possessing excellent thermal insulation and fire resistance. In this study, we prepared mullite nanofiber membranes (MNFMs) by electrospinning using polyethylene oxide and polyvinyl alcohol as dual templates. This method endows MNFMs with good flexibility and overcomes the inherent brittleness of ceramic fibers. And ensure that it can maintain structural integrity even when bent or folded without fragmentation or crushing. Simultaneously, the prepared MNFMs exhibit a lightweight and fluffy porous structure (0.02195 g cm−3), showing a remarkably low thermal conductivity of 0.035 W m−1 K−1. Moreover, it demonstrates excellent high-temperature resistance, withstanding temperatures as high as 1300 °C, and exceptional thermal insulation. The unique combination of these characteristics qualifies the MNFMs for a wide range of applications, such as high-temperature insulation, fire resistance, high-temperature filtration, flexible electronics, and high-temperature protective clothing. [ABSTRACT FROM AUTHOR]

Hollow-structured ceramic fibers with multiple components are ideal as lightweight insulation materials. In this study, tetraethyl orthosilicate, boric acid, and zirconia octahydrate were used as raw materials for fabricating SiZrBOC hollow ceramic fibers through coaxial electrospinning. These ceramic fibers exhibit a low thermal conductivity and an excellent temperature resistance. The electrospun SiZrBOC hollow ceramic fibers display a clean and compact morphology with internal folds. Fourier-transform infrared spectroscopy and thermogravimetric analysis (TGA) were used to assess the transformation process and thermal behavior of the hollow ceramic fibers. The results suggest that the incorporation of B promotes the formation of Si–O–B bonds within the system, leading to a maximum yield of 75.49 wt% for the production of the SiZrBOC hollow ceramic fibers. The phase composition and microstructure of the SiZrBOC hollow ceramic fibers were analyzed via X-ray diffraction (XRD) measurements. The pyrolysis at 1000 °C resulted in the appearance of diffraction peaks corresponding to SiO 2 and SiC in the XRD patterns of the SiZrBOC hollow ceramic fibers. Laser thermal conductivity measurements reveal that the SiZrBOC hollow ceramic fibers exhibit a thermal conductivity of only 0.06 W‧m−1K−1 at 25 °C and 0.124 W‧m−1K−1 at 500 °C, indicating a significantly superior thermal insulation performance compared with conventional solid SiZrBOC ceramic fibers. [ABSTRACT FROM AUTHOR]

Flexible pressure sensors have recently attracted increasing attention. Piezoresistive sensors are widely used in wearable devices, human health monitoring, electronic skin, human-computer interactions, and other fields owing to their good sensitivity and rapid response. The assembly of a pressure sensor using SnO 2 –ZnO hybrid nanofibers is proposed in this study to improve its performance. The heterojunction at the interface between ZnO and SnO 2 facilitates electron transfer from SnO 2 to ZnO by suppressing electron-hole recombination and accelerating electron motion in ZnO. The scaffold sensor, as compared to other reported pressure sensors, exhibits better flexibility, optimized sensitivity, and pressure sensing range, and can detect dynamic pressure over a wide range (0–60 kPa). The sensor exhibits strong sensitivity (11.5 kPa−1), fast response and recovery times of 42 and 28 ms, respectively, and durable cyclic stability (600 cycles). This sensor can quickly detect human motion from subtle deformations, including weak changes in the joints of the fingers, wrists, and elbows, with a bending degree of approximately 20°. Owing to its excellent performance, breathability, and washability, it can be directly attached to skin or clothing for long-term use and has broad application prospects in wearable electronics. [ABSTRACT FROM AUTHOR]

Gas sensors play an important role in environmental detection and exhaled breath biomarker detection. In this paper, Co 3 O 4 /TiO 2 core-shell NFs were synthesized by coaxial electrostatic spinning method. The morphology, structure and composition of the composites were analyzed by SEM, TEM, EDS, XRD and XPS. The results of conventional static gas sensitivity performance tests showed that the Co 3 O 4 /TiO 2 sensors exhibited a P-type response with excellent sensing performance to acetone. The higher response values and better selectivity of Co 3 O 4 /TiO 2 sensors for acetone were observed compared to Co 3 O 4 NFS and TiO 2 NFS sensors, and the shortcomings that cannot be recovered from TiO 2 NFS have also been significantly improved. In addition, the breath simulation experiments showed that the Co 3 O 4 /TiO 2 sensors have a lower acetone detection limit down to 500 ppb. The initial resistance of the Co 3 O 4 /TiO 2 sensor does not change significantly with relative humidity increasing, and the response value fluctuates by 1.5% at 300 °C. The enhanced acetone sensing performance of Co 3 O 4 /TiO 2 is ascribed to the heterojunction and porous structure which result in more adsorbed active sites on the material surface. With the advantages of low detection limit and high anti-humidity, Co 3 O 4 /TiO 2 gas sensors are expected to become a potential candidate for the detection of acetone in exhaled gas of patients with diabetes in clinical non-invasive testing. [ABSTRACT FROM AUTHOR]

A novel strategy has been devised to synthesize directly GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons by uniaxial electrospinning technique and subsequent fluorination approach. GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons with sheathed ribbon structure have large specific surface area and unique void space structure between the inner and outer ribbons, which enables materials possess extraordinary applications in cancer therapy, drug delivery, sensors, catalysis, etc. The average widths of the inner and outer layers of the GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons are 1.60 ± 0.03 μm and 1.87 ± 0.02 μm, respectively. Furthermore, GdF 3 :1%Tb3+,x%Sm3+@SiO 2 and GdF 3 :y%Tb3+,2%Sm3+@SiO 2 belt-in-belt structured nanoribbons (x = 0.5, 1, 2, 3, 4, 5; y = 0.1, 0.3, 0.5, 0.7, 1, 2) have also been successfully constructed to observe energy transfer phenomenon and tunable changes in light color. Energy transfer from Tb3+ ions to Sm3+ ions has been proved according to the measured luminescence spectra of the samples. More importantly, Tb3+, Sm3+ co-doped GdF 3 @SiO 2 belt-in-belt structured nanoribbons simultaneously exhibit multicolor luminescent and paramagnetic dual functional performances owing to the natural magnetic moment of Gd3+ ions, making materials have potential applications in flat-panel displays, lasers, biomarkers, and magnetic resonance imaging. In this work, a novel and high-efficient approach is presented to construct photoluminescence-magnetism dual functional GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons, providing theoretical basis and technical guidance for the simple construction of other nanomaterials with special structures. [ABSTRACT FROM AUTHOR]

Co-doping Eu2+/3+ in a single-phase phosphor is an efficient way to achieve emission color regulation, which possesses great prospective application prospects in anti-counterfeiting, optical temperature and optical pressure sensing. In this work, Eu2+/3+ co-doped Ca 5 (PO 4) 3 F microspheres were successfully prepared by ionic liquid-assisted electrospinning, and the morphologies changed from microspheres to microfibers by altering the viscosity of the solution. Furthermore, the formation mechanism of Ca 5 (PO 4) 3 F: Eu2+/3+ was proposed. The luminescence properties of Ca 5 (PO 4) 3 F: Eu2+/3+ samples were reported in detail, and emission behavior driven by excitation wavelength, temperature and pressure were revealed. Utilizing the excitation wavelength color development behavior of Ca 5 (PO 4) 3 F: Eu2+/3+ phosphors, the films prepared with Ca 5 (PO 4) 3 F: Eu2+/3+ and PVA displayed red or blue light at 254/365 nm. More importantly, the Ca 5 (PO 4) 3 F: Eu2+/3+ phosphor exhibited temperature and pressure sensitivity, due to the distinct emission behaviors of Eu2+ and Eu3+ ions in response to changes of temperature and pressure. Notably, Ca 5 (PO 4) 3 F: Eu2+/3+ phosphor exhibited remarkable pressure stability and sensitivity, with values of 84.6% and 24.98% GPa-1. Therefore, this multifunctional material possesses great potential applications in anti-counterfeiting and temperature as well as pressure sensing. In conclusion, this research furnishes a novel synthetic way for the preparation of fluorapatite, which holds significant importance in providing a relatively straightforward approach to combine these multi-functions in single-phase materials. [ABSTRACT FROM AUTHOR]

A novel strategy has been devised to synthesize directly GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons by uniaxial electrospinning technique and subsequent fluorination approach. GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons with sheathed ribbon structure have large specific surface area and unique void space structure between the inner and outer ribbons, which enables materials possess extraordinary applications in cancer therapy, drug delivery, sensors, catalysis, etc. The average widths of the inner and outer layers of the GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons are 1.60 ± 0.03 μm and 1.87 ± 0.02 μm, respectively. Furthermore, GdF 3 :1%Tb3+,x%Sm3+@SiO 2 and GdF 3 :y%Tb3+,2%Sm3+@SiO 2 belt-in-belt structured nanoribbons (x = 0.5, 1, 2, 3, 4, 5; y = 0.1, 0.3, 0.5, 0.7, 1, 2) have also been successfully constructed to observe energy transfer phenomenon and tunable changes in light color. Energy transfer from Tb3+ ions to Sm3+ ions has been proved according to the measured luminescence spectra of the samples. More importantly, Tb3+, Sm3+ co-doped GdF 3 @SiO 2 belt-in-belt structured nanoribbons simultaneously exhibit multicolor luminescent and paramagnetic dual functional performances owing to the natural magnetic moment of Gd3+ ions, making materials have potential applications in flat-panel displays, lasers, biomarkers, and magnetic resonance imaging. In this work, a novel and high-efficient approach is presented to construct photoluminescence-magnetism dual functional GdF 3 :Tb3+,Sm3+@SiO 2 belt-in-belt structured nanoribbons, providing theoretical basis and technical guidance for the simple construction of other nanomaterials with special structures. [ABSTRACT FROM AUTHOR]

Co-doping Eu2+/3+ in a single-phase phosphor is an efficient way to achieve emission color regulation, which possesses great prospective application prospects in anti-counterfeiting, optical temperature and optical pressure sensing. In this work, Eu2+/3+ co-doped Ca 5 (PO 4) 3 F microspheres were successfully prepared by ionic liquid-assisted electrospinning, and the morphologies changed from microspheres to microfibers by altering the viscosity of the solution. Furthermore, the formation mechanism of Ca 5 (PO 4) 3 F: Eu2+/3+ was proposed. The luminescence properties of Ca 5 (PO 4) 3 F: Eu2+/3+ samples were reported in detail, and emission behavior driven by excitation wavelength, temperature and pressure were revealed. Utilizing the excitation wavelength color development behavior of Ca 5 (PO 4) 3 F: Eu2+/3+ phosphors, the films prepared with Ca 5 (PO 4) 3 F: Eu2+/3+ and PVA displayed red or blue light at 254/365 nm. More importantly, the Ca 5 (PO 4) 3 F: Eu2+/3+ phosphor exhibited temperature and pressure sensitivity, due to the distinct emission behaviors of Eu2+ and Eu3+ ions in response to changes of temperature and pressure. Notably, Ca 5 (PO 4) 3 F: Eu2+/3+ phosphor exhibited remarkable pressure stability and sensitivity, with values of 84.6% and 24.98% GPa-1. Therefore, this multifunctional material possesses great potential applications in anti-counterfeiting and temperature as well as pressure sensing. In conclusion, this research furnishes a novel synthetic way for the preparation of fluorapatite, which holds significant importance in providing a relatively straightforward approach to combine these multi-functions in single-phase materials. [ABSTRACT FROM AUTHOR]

Ceramics are recognized as highly suitable materials for creating guided bone regeneration (GBR) barrier membranes due to their bioresorbable and osteoconductive properties. However, techniques have not been fully developed for the production of ceramic membranes with the appropriate fiber thickness and pore size. In this study, a thin silica nonwoven fabric with pores smaller than cells, achieved by nanofiber technology, was prepared by electrospinning, and its potential as a GBR barrier membrane was explored. In addition, efforts were made to elucidate the nanoscale fiber formation mechanism through molecular dynamics-based geometric optimization using solid-state 29Si-NMR data. As a result, a thin silica nonwoven fabric composed of nanofibers and micropores was prepared by electrospinning a silica gel prepared by lowering the TEOS-to-water ratio during the sol-gel reaction. Insufficient water addition during the sol-gel reaction caused a decrease in the number of siloxane bonds, resulting in a linear growth behavior of the silica molecules instead of the original network growth behavior. This led to a decrease in fiber thickness, which in turn caused a decrease in pore size. The thin silica nonwoven fabric showed exceptional performance in the cell occlusion ability test, suggesting its strong potential as a GBR barrier membrane. [ABSTRACT FROM AUTHOR]

The electrospinning technique is employed for the synthesized cobalt ferrite/carbon nanofibers, utilizing iso-propanol as the solvent. The nanofibers prepared are subjected to sintering at three different temperatures. A comprehensive analysis is carried out on the structural, morphological, dielectric, impedance, and electromagnetic shielding effectiveness within the X-band frequency range (8.2–12.4 GHz). The application of the Debye-Scherer formula yielded an estimated crystallite size of 22 nm. The electrical response of cobalt ferrite/carbon nanofibers pellet is characterized by employing impedance spectroscopy. Variations in impedance plane plots are discussed based on frequency dependent relaxation time modulations. The impact of sintering temperature is observed in terms of increased impedance values and modifications in the conduction mechanism. These changes are contributed to distinct hopping carriers' linkages between Fe3+-Fe2+ and Co3+-Co2+ ions. Dielectric studies are elucidated considering cation polarizability, colossal resistivity, and tangent loss. This study revealed notable characteristics of CoFe 2 O 4 /C nanofibers, including colossal resistivity (8.45 × 108 Ωcm), a dielectric constant of 22, and colossal tangent loss. The CoFe 2 O 4 /C nanofibers exhibit a characteristic electromagnetic interference (EMI) shielding performance of 30–35 dB. This remarkable shielding performance is observed in nanofibers with a 3 mm thickness, specifically in sample S1 that underwent sintering at a low temperature. The shielding effectiveness is demonstrated within the X-band frequency range. [ABSTRACT FROM AUTHOR]

Nanofibrous aerogel composites have emerged as most promising materials for their high-temperature insulation in complex environments due to their ultra lightweight, high elasticity, and superior thermal performance. However, the release of particles caused by weak bond strength between nanofibers and aerogel, lead to insulation failure which presents serious challenge. This research presents, a novel approach to mitigate the particle release and significantly improve the overall performance of nanofibrous aerogel composites. The proposed method involves the preparation of particle-free nanofibrous aerogel composites through unique combination of sol-aerogel blending, electrospinning, and freeze-casting processes. The effect of particle release has been successfully eliminated by embedding TiO 2 aerogel within SiO 2 nanofibers even under rigorous conditions (weight loss rate less than 0.57%). Furthermore, the resulting nanofibrous aerogel composite exhibits exceptional thermal insulation properties, with a low thermal conductivity of 0.0251 W/mK at room temperature. Additionally, the proposed composite material configuration demonstrates superior infrared radiation suppression performance resulting in an infrared transmittance of 39.52%. The lamellar structure of the nanofibers aerogel is tailored to provide high compressive strength (2.2 kPa at 40% strain), exceptional cyclic fatigue resistance after 50 cycles, and temperature (−196 to 500 °C) conditions. The outstanding combination of thermal and mechanical properties exhibited by these nanofibrous aerogel composites makes them highly promising for stable thermal protection in extreme environmental conditions. These novel materials promise great potential for application in various engineering industries where reliable thermal insulation is critical. [ABSTRACT FROM AUTHOR]

Nanomaterials-based gas sensors represent a ground-breaking endeavour that establishes a systematic and methodical approach to the detection of deleterious contaminants on a broad scale, particularly within the environmental and healthcare domains. In this context, we have commenced the synthesis of chromium-doped (0, 0.5, and 1 wt%) zinc oxide nanostructures through the utilization of an electrospinning technique, subsequently followed by a calcination process. The resultant chromium-doped zinc oxide nanostructures have been subjected to rigorous analysis, affirming their polycrystalline nature as well as the discernible impact of chromium dopants, as confirmed by the X-ray diffraction pattern. Interconnected irregularly shaped multi-grain particles with higher oxygen adsorption sites were confirmed by scanning electron microscope and X-ray photoelectron spectrometer. After analyzing the electrical and optical features, the fabricated sensing elements were tested for their sensing behaviour at room temperature and found to have a selective response towards ethanol vapour. Among the samples, 0.5 wt% chromium-doped zinc oxide exhibited a sensing response (S = 9.03 for 100 ppm) towards ethanol at room temperature. Additionally, the lower limit of detection was found to be 1 ppm, and the response and recovery times towards 100 ppm of ethanol are 41 & 81 s. Further, a thorough investigation into the influence of chromium dopants on the ZnO lattice has been conducted, revealing their pivotal role in augmenting the gas-sensing characteristics of the material. [Display omitted] • Electrospun nanostructures of undoped and Cr-doped ZnO. • Cr-dopant induced Zn and oxygen vacancies in ZnO lattice. • Sensing response of 9.03 for100 ppm of ethanol at room temperature. • Influence of Cr-dopants on the sensing characteristics of ZnO. [ABSTRACT FROM AUTHOR]

This study was conducted to fabricate aluminum (Al) matrix composites reinforced with titanium oxide (TiO 2) continuous nanofibers to study their mechanical properties. For this aim, the solution containing polyvinyl acetate, dimethylacetamide, acetic acid, and titanium isopropoxide was electrospun over an Al layer at different times of 1, 3, 5, 10, and 20 min. After heat treatment at 500 °C, sheets containing nanofibers were sintered and connected together by the hot pressing at 625 °C. The characterizing of the nanofibers and composites was performed using Transmission electron microscope (TEM), Atomic force microscope (AFM), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) equipped with Energy-dispersive X-ray spectroscopy (EDS) analysis to evident the TiO 2 nanofibers morphology and their distribution in the Al matrix. The mechanical properties of composites produced with different electrospinning times were studied. The results showed that maximum yield and tensile strength (about 98% and 62% increase compared to Al matrix, respectively) and toughness were obtained in the composites with electrospinning times of 3 and 5 min. Additionally, it was found that the composites hardness was continuously increased by increasing the time of electrospinning (almost 44% more than the Al matrix). However, the tensile and toughness values were decreased in the composites with more increasing the amount of TiO 2 nanofibers at electrospinning times of about 10 min and 20 min. Fracture surface results showed that the presence of large aggregates, breakage of TiO 2 nanofibers, and weak bonding between the Al sheets were the effective factors in the decrease of mechanical properties of these composites at more electrospinning times. [ABSTRACT FROM AUTHOR]

Electrospun silica nanofiber membranes show a high potential in many advanced environmental applications. However, little is known about their mechanical performance which could be a limiting factor for further innovation. It is shown in this work that silica nanofiber membranes have a completely different deformation behavior compared to conventional polymeric/thermoplastic nanofiber membranes, resulting from their significant differences in chemical and physical properties such as fiber interactions and porosity. Furthermore, storage at room temperature initiates remarkable changes in failure mechanisms, depending on the storage humidity, which can be accelerated via a thermal treatment. These changes are linked to the structural changes of the membrane resulting from its chemical reactivity towards moisture in the air. Additional interactions and crosslinks are observed, leading to fiber shrinkage and rearrangement. As a result, more contact points are created between nanofibers, creating additional friction forces and, as such, a complete shift in mechanical properties towards a stronger, stiffer, and more brittle material (tensile strength of 14.0 ± 3.8 MPa vs. 3.1 ± 0.4 MPa and failure strain of 0.9 ± 0.2% vs. 24.2 ± 1.0%). The silica nanofiber membranes thus allow mechanical tunability via altering the storage or treatment conditions. [Display omitted] • Silica nanofiber membranes show a different deformation behavior compared to thermoplastic PA6 nanofiber membranes. • A mechanical shift is observed in silica nanofiber membranes, depending on the treatment conditions. • The mechanical shift can be linked to structural changes resulting from its chemical reactivity. • Shrinkage and an increase in areal density are observed, leading to more fiber contact points. • Mechanical tunability is possible through treatment conditions. [ABSTRACT FROM AUTHOR]

As the cognition of metal oxide semiconductor becomes deeper and deeper, their excellent sensing ability has also been demonstrated. The gas sensors with metal oxide semiconductor as basis materials have become a hot topic at present. Enhancing the sensitivity and reducing the test limit of the sensor are exceedingly important topic. It is crucial to regulate the morphology of metal oxide semiconductor materials to improve the gas sensing performance. Low-dimensional materials such as quantum dots, one-dimensional nanowires and nanorods usually show the excellent gas-sensitive properties. In this work, one-dimensional YFeO 3 nanorods were synthesized by electrospinning technology. The one-dimensional rod-like structure enables more active sites to be exposed on the surface of materials, which can effectively promote the adsorption process of the YFeO 3 nanorods to the test gases, so as to improve the gas sensing performance. Found by testing the gas sensitivity, YFeO 3 nanorods responds far better to ethanol than other tested gases. The response and recovery time of YFeO 3 nanorods to 100 ppm ethanol at 350 °C was approximately 19 s and 9 s, respectively. It indicates that the response and recovery ability of YFeO 3 nanorods to ethanol were excellent. The study can provide technical reference for subsequent preparation of remarkable performance ethanol sensor and enrich the materials category of gas sensor fields. [ABSTRACT FROM AUTHOR]

Orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 nanofibers were prepared by electrospinning followed by a heat treatment. The effects of post-annealing temperatures on the phase composition, microstructure and morphology were investigated by XRD, SEM, HRTEM and XPS. Negative thermal expansion (NTE) behaviors of the In 0.5 Sc 1.5 Mo 3 O 12 nanofibers were analyzed by high-temperature XRD. Results indicate that the as-prepared In 0.5 Sc 1.5 Mo 3 O 12 nanofibers show an amorphous structure with smooth and homogeneous shape. The average diameter of the as-prepared In 0.5 Sc 1.5 Mo 3 O 12 nanofibers is around 515 nm. Well crystallized orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 nanofibers could be prepared after post-annealing at 550 °C for 2 h with an average diameter of about 192 nm. The crystallinity of In 0.5 Sc 1.5 Mo 3 O 12 nanofibers gradually improved with the increase of annealing temperature. However, too high post-annealing temperature leads to a damage of sample's fiber structure. The high-temperature XRD results reveal that In 0.5 Sc 1.5 Mo 3 O 12 nanofibers show an anisotropic NTE, and the coefficients of thermal expansion (CTEs) along a -axis and c -axis were −5.95 × 10−6 °C−1 and -3.54 × 10−6 °C−1, while the one along b -axis is 5.61 × 10−6 °C−1. The volumetric CTE of In 0.5 Sc 1.5 Mo 3 O 12 nanofibers is −3.90 × 10−6 °C−1 and the linear one is 1.3 × 10−6 °C−1 in 25–700 °C. [ABSTRACT FROM AUTHOR]

A novel and universal method combining electrospinning with a twi-crucible fluorinating technology was utilized to fabricate one-dimensional LaF 3 :RE3+ (RE = Eu, Nd) nanostructured phosphors. A series of nanofibrous/nanoribbon-shaped LaF 3 :RE3+ (RE = Eu, Nd) phosphors were devised and facilely fabricated through the calcination of the relevant nanofibrous/nanoribbon-shaped La 2 O 3 :RE3+ (RE = Eu, Nd) precursors in air by applying a twi-crucible fluorinating method utilizing NH 4 HF 2 as a fluorine source without additional usage of reducing gas and protective gas. Nanofibrous/nanoribbon-shaped La 2 O 3 :RE3+ (RE = Eu, Nd) precursors were synthesized by calcinating the electrospun nanofibrous/nanoribbon-shaped [RE(NO 3) 3 +La(NO 3) 3 ]/polyvinyl pyrrolidone (PVP) composites. Nanofibrous/nanoribbon-shaped LaF 3 :RE3+ (RE = Eu, Nd) phosphors possess hexagonal structures with a space group of P 6 3 / mmc. Nanofibrous LaF 3 :RE3+ (RE = Eu, Nd) phosphors present excellent fibrous morphology with a uniform diameter of 131–143 nm. Nanoribbon-shaped LaF 3 :Eu3+ phosphors with 94.5 nm in thickness and 5.1 ± 0.4 μm in width were acquired. Nanoribbon-shaped LaF 3 :Nd3+ phosphors have a thickness of 179 nm and a width of 4.2 ± 0.4 μm. Upon excitation by ultraviolet light at 396 nm, nanofibrous/nanoribbon-shaped LaF 3 :Eu3+ phosphors emit the main emission band at approximately 591 nm, corresponding to the 5D 0 →7F 1 magnetic dipole transition of Eu3+. With an increment of Eu3+ concentration, the fluorescent strength of nanofibrous LaF 3 :Eu3+ phosphors is improved greatly and achieves a maximum when the Eu3+ concentration is approximately 5 mol%. Moreover, the nanofiber/nanoribbon-shaped LaF 3 :Eu3+ phosphors emit a yellow color. For Nd3+-doped phosphors, nanofibrous/nanoribbon-shaped LaF 3 :Nd3+ phosphors possess near-infrared optical performances, and the main emission peak is at 854 nm, corresponding to the 4F 3/2 → 4I 9/2 transition of Nd3+. The luminescence intensity of LaF 3 :Nd3+ phosphors decreases significantly with increasing Nd3+ content and reaches a maximum at 5 mol% Nd3+. The corresponding formative mechanisms of nanofibrous/nanoribbon-shaped RE3+ (RE = Eu, Nd) phosphors are expounded, and the corresponding construction technique is established. The new findings in this work lay a foundation for wide applications of rare earth fluoride one-dimensional nanostructures. [Display omitted] • 1D LaF 3 :RE3+ nanostructure is made by electrospinning with twi-crucible fluorinating. • Nanostructures include nanofibrous and nanoribbon-shaped LaF 3 : RE3+ phosphors. • Different nanostructures are facilely obtained by modulating spinning parameters. • Luminescent intensity can be tunable by variation of Eu3+/Nd3+ concentrations. • Possible forming mechanisms of LaF 3 : Eu3+/Nd3+ 1D nanostructures are advanced. [ABSTRACT FROM AUTHOR]

Photochromism has shown to be a promising tool for improving the authenticity of commercially available products. Additionally, improving the engineering process of authentication patterns has been crucial to offer mechanically reliable anticounterfeiting nanofibers. Herein, the electrospinning technology was applied to develop mechanically reliable and photoluminescent silicon dioxide-based electrospun glass nanofibers (80–110 nm) embedded with lanthanide-activated aluminate (LA) nanoparticles (NPs; 1–2 nm) for anticounterfeiting purposes. The produced nanocomposite films exhibited photochromism from colorless in visible spectrum to green under ultraviolet irradiation. The nanofibrous film transparency was maintained by presenting the strontium aluminate pigment as nano-scaled particles, which improves its distribution and prevents the formation of aggregates in the electrospun glass nanofibrous bulk. After being excited at 365 nm, the nanofibers made of phosphor@glass (LANPs@GLS) displayed an emission band at 519 nm. Increases in the pigment ratio enhanced the hydrophobicity of the LANPs@GLS nanofibers without altering their intrinsic characteristics. The LANPs@GLS films exhibited fast and reversible photochromism without fatigue when activated by UV light. Transparency and flexibility were shown by the nanofibrous mats. The proposed technique is reliable for making a wide range of anticounterfeiting materials. [ABSTRACT FROM AUTHOR]

Expanding the spectral response range to near-infrared (NIR) region and improving carrier separation are the two critical strategies to obtain highly efficient photocatalysts for water pollution control. Herein, a new type of photocatalyst one-dimensional/zero-dimensional (1D/0D) BiVO 4 :Er/Yb@Ag/Ag 3 PO 4 Z-scheme heterostructure with full spectral response is constructed by an electrospinning coupled with an ethylene glycol assisted hydrothermal method. The optimized BiVO 4 :Er/Yb@Ag/Ag 3 PO 4 heterostructured nanofibers degrade 69.5% (9 h) and 91.3% (30 min) of tetracycline hydrochloride (TC), 76.7% (9 h) and 99.4% (24 min) of methylene blue (MB) and 38.2% (9 h) and 94.5% (60 min) of bisphenol A (BPA) under NIR light and simulated sunlight excitation, respectively. Under NIR light and simulated sunlight excitation, the MB removal efficiencies of the optimal composite are 9.833 and 1.094 times of Ag 3 PO 4 and 20.184 and 11.558 times of BiVO 4 , respectively. The superior photocatalytic activity can be attributed to the synergistic effects of the unique 1D/0D contact interface, the porous outer wall of BiVO 4 :Er/Yb nanofibers, Ag bridged Z-scheme heterostructure, upconversion (UC) luminescence and the surface plasmon resonance (SPR) effect. This makes BiVO 4 :Er/Yb@Ag/Ag 3 PO 4 heterostructured nanofibers have the advantages of broadened absorption spectrum, abundant active sites, increased specific surface area, fast electron transfer channels, improved carrier separation efficiency, enhanced photocorrosion resistance and stability. This work provides a new insight in designing and constructing high-performance Ag bridged Z-scheme heterostructure photocatalysts with full spectral response for water pollution control. [Display omitted] • Full-spectrum-active BiVO 4 :Er/Yb@Ag/Ag 3 PO 4 1D/0D core-shell photocatalyst is devised. • 1D/0D nanostructure provides more active sites and avails fast transfer of carries. • Rare earth UC fluorescence and plasmon effect jointly enhance photocatalytic ability. • SPR effect of Ag NPs avails the carrier separation and light absorption enhancement. • Photocatalyst has degradation of dye, endocrine disruptor and antibiotic trifunction. [ABSTRACT FROM AUTHOR]

Nanofibrous Zr x Ti 1-x O 2 (x = 0.9–0.2) ceramic materials were produced using a high-yield, free surface alternating field electrospinning (AFES) process (a.k.a. AC-electrospinning) from metal alkoxide precursor solutions. Depending on the precursor composition, the production rates of 4.8–6.4 g/h in terms of the resulting ceramic nanofibers were demonstrated with a single-electrode AFES system. The average diameter of Zr x Ti 1-x O 2 fibers varied in the range of 190–435 nm, depending on the alkoxide/polymer mass ratio in the precursor and annealing temperature. Zr/Ti molar ratio is a key factor that determines the crystallization temperature and phase composition of Zr x Ti 1-x O 2 nanofibers after thermal processing between 600 and 1200 °C, but it has a moderate effect on textural properties of the resulting nanofibers. When the molar fraction of zirconia is > 0.7, the nanofibers are composed primarily of a nanocrystalline titania-rich TiO 2 –ZrO 2 solid solution without the formation of separate TiO 2 phase. At zirconia molar fraction of 0.5, stable orthorhombic Zr 0.5 Ti 0.5 O 2 zirconium titanate structure forms above 680 °C. TiO 2 (anatase or rutile) forms as a separate phase in addition to Zr x Ti 1-x O 2 phases when Zr molar fraction is 0.2, depending on the annealing temperature. The results of this study demonstrate that a large variety of nanofibrous ZrO 2 –TiO 2 ceramic materials with tailored compositions can be efficiently prepared for targeted applications by using free-surface AFES and appropriate thermal processing. [ABSTRACT FROM AUTHOR]

The present work is focused on the preparation and characterization of composite nano/microfibers based on alumina applicable as fillers in ceramic-matrix composites. The graphene-coated Al 2 O 3 microfibers have been prepared in the form of continuous alumina/graphene fibers from electrospun precursors using needle-less electrospinning, calcination, and catalyst-free chemical vapor deposition of graphene layers on the surface of the microfibers. The phase composition and morphology of the composite fibers were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning, and transmission electron microscopy (SEM and TEM). The porosity of the final fibers was evaluated by low-temperature nitrogen adsorption. The surface microstructures of composite fibers were rough and their diameters were in the range from 300 nm to 2 μm. The phase transformation at 1100 °C led to the formation of a mixture of γ-, δ-, and α-Al 2 O 3. TEM results confirmed that the alumina fibers were covered by the 3–4 layers of graphene-based structure. The specific surface area of pure alumina fibers after carbon deposition slightly increased from the initial 40 m2/g to 45 m2/g, due to a slightly wavy surface of graphene layers. Raman spectroscopy and XPS analysis results showed that the surface layer of fibers is formed as graphene oxide. Between the graphene oxide and alumina grains a chemical bonding C–O–Al, C–O–O–Al was discovered as the nucleation of the graphene oxide sheet. The growth mechanism of graphene oxide layers on the surface edges of Al 2 O 3 grains was described. [ABSTRACT FROM AUTHOR]

Zirconate fibrous membranes show promising applications in high thermal insulating areas for the high melting point, low thermal conductivity and good phase stability. To satisfy the high-temperature mechanical demands, the microstructure of zirconate fibers needs further modification to accommodate high-temperature stability. In consideration of the slow ion diffusion rate and enhanced stability of solid solution, Ca x Sr 1- x ZrO 3 fibrous membranes were electrospun with molar ratio of Ca/Sr varied from 0.9 to 0.5 for the present work. The effects of strontium precursor on the pyrolysis process, phase formation and microstructure evolution were fully characterized. Modified microstructures with smaller grain size and narrow particle size distribution were achieved. Furthermore, the NIR reflectivity, thermal conductivity, and high-temperature stability were also presented. The special expansion character of fibrous membrane at high temperature would make it promising candidate to compensate the shrinkage of other oxide fibrous membrane. [ABSTRACT FROM AUTHOR]

In the recent years, MXenes (2D transition metal carbides, carbon nitrides and nitrides) and its precursor MAX phases have been widely investigated in electrochemical research. In this research, we successfully prepared a core-shell structured compound——Ti 3 C 2 @Ti 2 SnC/CNFs (MXene@TSC/C) as an anode material for lithium ion battery via electrospinning method. Results showed that this type of compound has a specific capacity of 288.9 mAh·g−1 at the current density of 0.4 A g−1 after 300 cycles, accompany with a retention rate of capacity of 105.4% in the rate performance test. These performances were benefit from the core-shell structured CNFs and Ti 3 C 2 MXenes. This work supported a novel way to improve the electrochemical property of MXene and MAX phases, which was expected to further explored. [ABSTRACT FROM AUTHOR]

With the increasingly serious issues of energy conservation and emission reduction, hollow fibers have attracted wide attention as materials that have structural advantages in terms of thermal insulation. Herein, we report the preparation of flexible hollow TiO 2 fibrous membranes via coaxial electrospinning. To optimize the thermal-insulation performance of the fibers, hollow fibers with different diameters and pore sizes were prepared by adjusting the feeding rate of the core spinning solution. Optimum conditions were achieved at a feeding rate of 2 mL/h for the shell solution and 0.4 mL/h for the core solution. The hollow fibers had a compact tube wall structure and good mechanical properties, and the tensile strength of the fibrous membranes reached 0.652 ± 0.119 MPa. In addition, the hollow fibrous membranes have excellent thermal insulation properties with an average reflectance of more than 89% and a room temperature thermal conductivity of less than 0.0294 ± 0.00015 W m−1K−1. In practical experiments, the temperature can be reduced from 1174.6 to below 273.6 °C using 15-mm-thick fibrous membranes, which confirms its excellent thermal insulation. Flexible hollow TiO 2 fibrous membranes have a wide range of insulation applications. [ABSTRACT FROM AUTHOR]

A novel magnetic resonance imaging (MRI) diagnostic nanofibres were synthesised using Er 2 O 3 nanoparticles (2% to 8%) embedded in the PEO matrix via electrospinning. The prepared PEO/Er 2 O 3 nanofibres were fully characterised, and the magnetic relaxivity study for MRI contrast enhancement was evaluated. The findings showed that the fibre diameter became broader with increasing nanofiller loading. The encapsulation of Er 2 O 3 nanoparticles in PEO fibres demonstrated excellent entrapment efficiency using the electrospinning method. The reduction of the crystallinity index provoked changes in the crystallite size, thus contributing to the amorphous component. The addition of Er 2 O 3 nanoparticles in the PEO matrix demonstrated the changes in the conformational structure of the peak intensity, shape and position of the C–O–C stretching absorptions. PEO/Er 2 O 3 nanofibres have successfully demonstrated potential T 2 and T 1 -T 2 dual-mode diagnostic nanofibres in MRI 1.5 T. Therefore, it is considered a great achievement in the detection sensitivity for cancer diagnosis due to its potential diagnostic use that can be activated in two-way. • The effect of the interfacial interaction between the crystallisation of the polymer on the nanofiller surface. • The effect of nanofiller addition on the conformational structure of the polymer matrix. • The efficiency of PEO/Er 2 O 3 nanofibres as T 2 and T 1 -T 2 dual-mode diagnostic nanofibres. [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]

In this study, a novel Cu(II)-Chitosan/PVA electrospun coating containing different concentrations of Cu(II) was applied to AZ31 magnesium alloy samples, pre-treated with the MAO (micro-arc oxidation) method, in order to enhance its antibacterial activity, cell viability, and corrosion resistance for orthopedic applications. Structure and morphology, water absorption and wettability, Cu(II) ion release, antibacterial activities, and cell biology were all studied in these coatings. Electrochemical impedance spectroscopy (EIS) was used to determine the corrosion resistance of the coatings. SEM images showed that all fibers of electrospun samples exhibited crack-free, unbeaded, and uniform fibrous structures with an average diameter range of about 220–340 nm. The corrosion resistance of the MAO pretreatment enhanced cell viability, and the unique structure of the electrospun layer promoted cell attachment and proliferation to the coating. The coatings demonstrated satisfactory antibacterial activity against both gram-positive and gram-negative bacteria. Furthermore, coatings with higher Cu(II) concentrations released more Cu(II) ions, resulting in improved antibacterial properties. However, despite the reduced cell viability for the coatings containing 8.42% Cu(II), the cell viability of the coatings with 0.77% and 2.97% Cu(II) was not significantly affected, and they were not harmful to MG63 cells, but high concentrations of Cu(II) ions caused significant cytotoxicity. [ABSTRACT FROM AUTHOR]

Flexible piezoelectric nanogenerators based on polyvinylidene difluoride (PVDF) and lead magnesium niobate-lead titanate Pb(Mg 1/3 Nb 2/3)O 3 –PbTiO 3 (PMN- x PT compositions for x between 30 and 35) particles with various filler ratios from 10 to 30 vol% were fabricated through the electrospinning method. The phase and microstructural characterizations revealed that the homogenous and continuous fiber-shaped composite structure with good interfacial interaction between the PMN-PT particles and the PVDF matrix was achieved. It was found that the diameter of the neat PVDF fibers was approximately 354 nm, whereas the PVDF/PMN-35PT fibers with ceramic particle concentrations of 10, 20, and 30 vol% had average diameters of 317, 249, and 163 nm, respectively. The piezoelectric performance tests indicated that the 30 vol%PVDF/PMN-35PT nanogenerator had a 3 times greater electrical power efficiency (10.59 μW) at 20 Hz compared to that of the pure PVDF nanogenerator (3.56 μW) at 15 Hz under the same resistance load of 1 MΩ. All in all, the incorporation of PMNT-PT particles into the PVDF appears to be a good approach for the fabrication of high-performance flexible piezoelectric nanogenerator applications for biomechanical energy harvesting of devices converting the mechanical movements of organs such as cardiac and lung into electrical energy. [ABSTRACT FROM AUTHOR]

The degradation of the cobalt-zinc oxide structure and its poor conductivity during the charge and discharge limit their further applications for lithium ion storage. Herein, ZnCo 2 O 4 @carbon nanofiber composite with nano-fibrous structure is obtained by electrospinning, annealing in argon and low-temperature oxidation to effectively overcome the above issue. The active sites of ZnCo 2 O 4 are evenly dispersed inside the carbon nanofibers, which can effectively avoid its aggregation and improve electrical conductivity. Additionally, the stable nanofibrous structure can maintain structural stability. The composite exhibits superior lithium ion storage capacity when being served as anode electrode. The ZnCo 2 O 4 @carbon nanofiber electrode possesses a high capacity of 1071 mA h g−1 at 0.1 A g−1. Besides, the electrode shows an outstanding rate capability of 505 mA h g−1 at 3 A g−1 and maintain 714 mA h g−1 after 250 cycles when current density is adjusted to 0.2 A g−1 again. Additionally, the electrode has an outstanding long-cycle performance, which remains a capacity of 447.165 mA h g−1 at 0.5 A g−1 after 500 cycles and 421.477 mA h g−1 at 1 A g−1 after 518 cycles. This result demonstrates that ZnCo 2 O 4 @carbon nanofiber composite has potential application prospects in the fields of advanced energy storage. [ABSTRACT FROM AUTHOR]

Enhancing photogenerated carrier separation and broadening the spectral response range are key factors in obtaining effective photocatalysts for organic pollutant degradation. Based on morphology control and reasonable structure design, herein, a novel S-scheme heterojunction of BiVO 4 :Er3+,Yb3+/BiOCl with a one-dimensional/two-dimensional (1D/2D) core-shell structure is constructed by electrospinning combined with a solvothermal method. Consequently, BiVO 4 :Er3+,Yb3+/BiOCl composite nanobelts degraded 97.9% and 66.1% methylene blue (MB), 88.8% and 68.8% tetracycline hydrochloride (TCH) and 80.8% and 22.2% bisphenol A (BPA) driven by simulated sunlight and NIR light, respectively. The superior catalytic performance can be attributed to the synergism between upconversion (UC) fluorescence, the unique core-shell nanobelt-shaped structure and the S-scheme heterostructure, which enables the strong interface interaction between components to effectively expand the spectral absorption range, enhance the separation and utilization efficiency of photoinduced carriers, and endow the carriers with stronger redox ability. This work can provide a new idea for the design of a 1D/2D S-scheme heterojunction photocatalyst with a full-spectrum response for water purification. [Display omitted] • Full-spectrum-active BiVO 4 :Er3+,Yb3+/BiOCl heterostructure photocatalyst is designed. • 1D/2D nanostructure provides more active sites and avails fast transfer of carries. • S-scheme heterojunction availably promotes separation of photo-induced carriers. • Yb3+/Yb2+ redox centers avail photo-induced carrier separation and boost ∙O 2 −content. • Photocatalyst has degradation of dye, endocrine disruptor and antibiotic trifunction. [ABSTRACT FROM AUTHOR]

Developing new photodetectors with good photoresponse, high stability, flexibility, and minimalization is urgently demanded facing the rapid development of optical technology. In this work, ZnO–SnO 2 heterojunction nanofibers are synthesized by electrospinning. The flexible UV micro-photodetector is fabricated by combining ZnO–SnO 2 heterojunction nanofibers with photolithography-patterned Au microelectrodes on PI substrate. An extremely low dark current (∼10−11 A) is obtained due to the formation of Zn 2 SnO 4 layer at the large interface of ZnO–SnO 2 heterojunctions. Upon exposure to UV light with power density of 24 μW cm−2, the photodetector exhibits high on–off ratio of ∼104, high responsibility of 267 A W−1, and fast response speed of 2.75 s. The photodetector has good photoelectric properties and high UV selectivity. Moreover, the flexibility of the UV photodetector is demonstrated. The photoresponse remains ∼60% of the initial level even under a large bending angle of 45°. The combined utilization of electrospinning and photolithography is convenient to fabricate flexible UV photodetectors. [ABSTRACT FROM AUTHOR]

Orthorhombic Sc 2 (MoO 4) 3 nanofibers have been prepared by ethylene glycol assisted electrospinning method. The effects of annealing temperature, precursor concentration, spinning distance and solvent on the preparation of Sc 2 (MoO 4) 3 nanofibers were characterized by XRD, SEM, HRTEM, EDX and high-temperature XRD. XRD analysis shows as-prepared nanofibers are amorphous. Orthorhombic Sc 2 (MoO 4) 3 nanofibers can be fabricated after annealing at different temperatures in 500–800 °C for 2 h. The crystallinity of Sc 2 (MoO 4) 3 nanofibers improves and the nanofiber diameter decreases gradually as the annealing temperature increases. However, the nanofiber structure was destroyed at the annealing temperature above 700 °C. Higher precursor concentration results in a slight increase of diameter and decrease in destroying temperature of Sc 2 (MoO 4) 3 nanofibers. Spinning distance also affects the diameter of nanofibers, and the nanofiber diameter decreases as the distance increases. One-dimensional orthorhombic Sc 2 (MoO 4) 3 nanofibers exhibit anisotropic negative thermal expansion. In 25–700 °C, the coefficients of thermal expansion (CTE) of α a , α b and α c are −5.81 × 10−6 °C−1, 4.80 × 10−6 °C−1 and -4.33 × 10−6 °C−1, and the α l of Sc 2 (MoO 4) 3 nanofibers is −1.83 × 10−6 °C−1. [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]

Herein, a novel flexible SiO 2 aerogel composite nanofiber membrane with strawberry-like structure and excellent thermal insulation properties, in which SiO 2 aerogel particles act as thermal insulation filler, was prepared by electrospinning technology. With the addition of nano-pore structure SiO 2 aerogel particles, the heat transfer path of the fibers inside the membrane became discontinuous, endowing the as-prepared membrane an ultra-low thermal conductivity of 30.3 mW/(m⋅K) and large surface area of 240 m2/g. Moreover, the nanofibers membrane also possesses the combined merits of excellent fire resistance, high-temperature stability, and temperature-invariant flexibility, rendering it a promising in the application of insulation and gas adsorption. The successful preparation of this flexible nanofiber membrane paves a new way to design materials with excellent thermal insulation and adsorption properties. [ABSTRACT FROM AUTHOR]

This study describes the preparation and characterization of PVP-PEO nanofibers filled with PbS nanoparticles. The effect of polymer concentrations, surface morphology, and diameter distribution studies of the nanofibers was evaluated by Scanning Electron Microscopy (SEM). The SEM images revealed that smooth and homogeneous nanofibers could be achieved at 12% PVP-PEO (50:50 wt%) concentration. The XRD and TEM analysis confirmed the formation of PbS nanoparticles in the PVP-PEO blend matrix, which also revealed the high crystalline behaviour of the PbS nanoparticles. The XRD data showed that the intensity and average crystallite size increase with PbS concentration. The FTIR and TGA studies revealed the interaction between PbS nanoparticles and the PVP-PEO blend matrix. UV–Vis diffuse reflectance studies have shown that the reflectance onset shifted toward a blue shift than bulk PbS. The optical bandgap determined using the Kubelka-Munk function lies 1.08–1.56 eV range by varying PbS concentration. [ABSTRACT FROM AUTHOR]

Fe/C core-shell nanofibers were prepared via a coaxial electrospinning technique integrated with high-temperature carbonization, in which the Fe(NO 3) 3 -containing PAN solution and Fe(NO 3) 3 constituted the shell and core structures, respectively. The core-shell structure was perfectly maintained after carbonization, and Fe nanoparticles were uniformly distributed within the carbon nanofibers. The effects of the microscopic morphology and crystallinity of the carbon components on the electromagnetic properties, matching characteristics, and electromagnetic wave absorption properties of the Fe/C nanofibers were investigated by adjusting the carbonization temperature. As-prepared Fe/C-800 °C core-shell nanofibers mixed with 10 wt% of paraffin showed a minimal reflection loss (RL min) of −20.6 dB under 11.52 GHz at 2.5 mm of thickness and lower than −20 dB under 2.3–5.0 mm of thickness. The efficient absorption bandwidth (EAB) was 6.24 GHz in the range of 11.76–18 GHz at 2.1 mm, covering the whole Ku band. The absorption bandwidth can cover the whole X and Ku bands by varying the sample thickness. The efficient absorption bandwidth was 3.84 GHz in the range of 8.08–11.92 GHz at 2.9 mm, covering the X band. The effective complementarities between the magnetic loss of Fe nanoparticles, the dielectric loss of PAN-based carbon, and the core-shell structure promoted impedance matching and multiple interface polarization, endowing the produced composites with prominent absorption characteristics of microwaves. Therefore, the prepared Fe/C core-shell nanofibers are an ideal lightweight and broadband electromagnetic wave (EMW)-absorbing material that exhibits high-performance microwave absorption. [ABSTRACT FROM AUTHOR]