Search Results (244)

SCM-10 is an SFE-type borosilicate zeolite featuring one-dimensional 12-ring channels and holds promise for catalytic and separation applications, yet its crystallization and morphology control remain insufficiently understood. Herein, we investigate the crystallization of SCM-10 and elucidate the effects of synthesis parameters, including SiO₂/B₂O₃, OSDA/SiO₂, and H₂O/SiO₂ molar ratios, crystallization temperature, and heteroatom substitution, on crystal morphology. SCM-10 crystallizes via an induction period (30 h) followed by rapid crystal growth (12 h), yielding uniform needle-like crystals with dimensions of 0.05 × 1 μm (diameter × length; aspect ratio = 20). Increasing the SiO₂/B₂O₃ ratio induces a morphology transition from needles to plates, whereas variations in the OSDA/SiO₂ and H₂O/SiO₂ ratios largely preserve the needle-like morphology. Elevating the crystallization temperature transforms needles into nanowires, with the aspect ratio rising to 83 (0.03 × 2.5 μm). Heteroatom substitution further induces distinct morphology modulation: Al yields nanoparticles (100 nm), V shortens crystal lengths to 500 nm (50 × 500 nm; aspect ratio = 10), Fe produces nanowires (0.02 × 1.3 μm; aspect ratio = 65), and Ge forms peanut-like needle aggregates (0.05 × 10 μm; aspect ratio = 200). This work establishes morphology-regulation rules for SCM-10, enabling the rational design of tailored morphologies for applications. Full article

Traditional hydroxyapatite materials are inherently stiff and brittle, limiting their applications. Flexible ultralong hydroxyapatite nanowires, characterized by nano-scale diameters and micrometer-scale lengths, offer a promising alternative as one-dimensional flexible building blocks for constructing high-performance biomimetic materials. Nature has evolved a variety of high-performance materials with hierarchically ordered structures assembled from nano-scale building blocks, which provide valuable insights into the design and ordered assembly of flexible nanofibers for building high-performance biomimetic materials. Currently, how to distill the structural design principles of natural materials to engineer flexible nanofibers into advanced high-performance biomimetic materials with excellent properties and multifunctions remains a frontier scientific challenge. In 2014, the authors’ research group reported for the first time the calcium oleate precursor solvothermal method for the synthesis of flexible ultralong hydroxyapatite nanowires and their applications. Since then, many soft functional materials and high-performance biomimetic materials have been designed and prepared using flexible ultralong hydroxyapatite nanowires, and their applications in various fields have been explored. These studies demonstrate the successful assembly of flexible ultralong hydroxyapatite nanowires into hierarchical biomimetic structures inspired by natural materials such as enamel, nacre, and bone, which exhibit enhanced mechanical properties, including improved strength, toughness, and flexibility, alongside multifunctional capabilities like thermal insulation and biomedical compatibility. These findings suggest that flexible ultralong hydroxyapatite nanowires provide a versatile platform for designing and constructing advanced biomimetic materials with promising applications in various fields. This review article aims to briefly review recent advances in this exciting and rapidly evolving research field. The synthetic methods, assembly strategies, properties, and applications of flexible ultralong hydroxyapatite nanowires and their derivative biomimetic materials are discussed, enlightening their structural design principles and potential applications. Finally, we propose future research directions and future perspectives in this exciting frontier research field. Full article

We present a theoretical examination of the fractional dynamics of information entropy within a semiconductor nanowire system influenced by Rashba spin–orbit interaction and external magnetic fields. Moreover, we determine the fractional nanowire state through the analytical solution of the fractional Schrödinger equation, considering various initial states of the nanowire system. Our research emphasizes the impact of the fractional order and the interaction parameters on the behavior of information entropy. Our findings reveal that the temporal behavior of information entropy is highly sensitive to any variations in the magnetic field length, the Rashba spin–orbit interaction, and the fractional order parameter. The results demonstrate that these parameters are pivotal in determining the coherence and correlation properties of the nanowire system. Therefore, precise control of these factors paves the way for enhancing entanglement performance and facilitating information transfer in spintronic and quantum communication applications. Full article

This work studies the impact of different physical and material parameters on the channel resistance, $R_{ch}$, and threshold voltage, $V_{th}$, of nanowire field-effect transistors (NWFETs). In particular, by means of detailed numerical simulations, we investigate the role of the channel length, nanowire diameter, gate oxide thickness, channel-doping concentration, energy bandgap, oxide thickness, and gate oxide permittivity in a wide range of temperatures (200–500 K). Our findings show that optimal values for both $R_{ch}$ and $V_{th}$ are achieved by reducing the nanowire channel length, as well as by increasing the nanowire diameter and doping concentration. Furthermore, NWFETs benefit from using wide-bandgap materials and thinner oxide layers with a higher permittivity. Notably, in short-channel NWFETs operating under ballistic transport, channel resistance remains nearly constant with temperature, governed by quantum conductance and injection statistics rather than temperature-sensitive scattering. These results underscore the complex interplay between material selection, doping levels, and device geometry in shaping the threshold voltage and the channel resistance of NWFETs. Also, they are useful for enhancing the device stability and advancing the design of NWFETs for the next-generation of nanoscale transistors. Full article

This study investigates the morphological evolution of epitaxial indium antimonide (InSb) nanowires (NWs) grown via chemical vapor deposition (CVD). We systematically explored the influence of key growth parameters—temperature (300 °C to 480 °C), source material composition, gold (Au) nanoparticle catalyst size, and growth duration—on the resulting NW morphology, specifically focusing on NW length and tapering. Our findings reveal that the competition between axial and radial growth modes, which are governed by different growth mechanisms, dictates the final nanowire shape. An optimal growth condition was identified that yields straight and minimally tapered InSb NWs. High-resolution transmission electron microscopy (TEM) confirmed that these nanowires grow preferentially along the <110> direction, and electrical characterization via field-effect transistor (NW-FET) measurements showed that they are n-type semiconductors. Full article

To expand the application of silver nanowires (AgNWs) in the field of flexible sensors, this study developed a stretchable flexible sensor based on thermoplastic polyurethane (TPU). Initially, the TPU nanofiber membrane was prepared by electrospinning. Subsequently, high-aspect-ratio AgNWs were synthesized via a one-step polyol reduction method. The AgNWs with the optimal aspect ratio were selected for the conductive layer and spray-coated onto the surface of the TPU nanofiber membrane. Another layer of TPU nanofiber membrane was then laminated on top, resulting in a flexible thin-film sensor with a “sandwich” structure. Through morphological, chemical structure, and crystallinity analyses, the primary factors influencing AgNWs’ growth were investigated. Performance tests revealed that the prepared AgNWs had an average length of approximately 130 μm, a diameter of about 80 nm, and an average aspect ratio exceeding 1500, with the highest being 1921. The obtained sensor exhibited a low initial resistance (26.7 Ω), high strain range (sensing, ε = 0–150%), high sensitivity (GF, over 19.21), fast response and recovery time (112 ms), and excellent conductivity (428 S/cm). Additionally, the sensor maintained stable resistance after 3000 stretching cycles at a strain range of 0–10%. The sensor could output stable and recognizable electrical signals, demonstrating significant potential for applications in motion monitoring, human–computer interaction, and healthcare fields. Full article

In this study we report on the structural, mechanical, and electrical characterization of different structures of vertically aligned zinc oxide (ZnO) nanowires (NWs) synthesized using hydrothermal methods. By optimizing the growth conditions, scanning electron microscopy (SEM) micrographs show that the ZnO NWs could reach an astounding 51.9 ± 0.82 µm in length, 0.7 ± 0.08 µm in diameter, and 3.3 ± 2.1 µm⁻² density of the number of NWs per area within 24 h of growth time, compared with a reported value of ~26.8 µm in length for the same period. The indentation modulus of the as-grown ZnO NWs was determined using contact resonance (CR) measurements using atomic force microscopy (AFM). An indentation modulus of 122.2 ± 2.3 GPa for the NW array sample with an average diameter of ~690 nm was found to be close to the reference bulk ZnO value of 125 GPa. Furthermore, the measurement of the piezoelectric coefficient (d₃₃) using the traceable ESPY33 tool under cyclic compressive stress gave a value of 1.6 ± 0.4 pC/N at 0.02 N with ZnO NWs of 100 ± 10 nm and 2.69 ± 0.05 µm in diameter and length, respectively, which were embedded in an S1818 polymer. Current–voltage (I-V) measurements of the ZnO NWs fabricated on an n-type silicon (Si) substrate utilizing a micromanipulator integrated with a tungsten (W) probe exhibits Ohmic behavior, revealing an important phenomenon which can be attributed to the generated electric field by the tungsten probe, dielectric residue, or conductive material. Full article

In this study, we propose a method for systematic nanowire length control through the precise control of the polyvinylpyrrolidone (PVP) concentration during the synthesis of tellurium nanowires. Furthermore, we report the changes in the electrical properties of thin-film transistor (TFT) devices with different lengths of synthesized tellurium nanowires used as channels. Through the use of scanning electron microscopy (SEM) and atomic force microscopy (AFM), it was determined that the length of the wires increased in relation to the amount of PVP incorporated, while the diameter remained consistent. The synthesized long wires formed a well-connected percolation network with a junction density of 4.6 junctions/µm², which enabled the fabrication of devices with excellent electrical properties, the highest on/off ratio of 10³, and charge mobility of 1.1 cm²/V·s. In contrast, wires with comparatively reduced PVP content demonstrated a junction density of 2.1 junctions/µm², exhibiting a lower on/off ratio and reduced charge mobility. These results provide guidance on how the amount of PVP added during wire growth affects the length of the synthesized wires and how it affects the connectivity between the wires when they form a network, which may help optimize the performance of high-performance nanoelectronic devices. Full article

In this article, femtosecond laser scanning was used to create heterojunctions between silver nanowire (Ag NW) and graphene oxide (GO), resulting in a mechanical and electrical interconnection. Surface plasmon resonances (SPRs) were generated on the nanowire surface by using femtosecond laser irradiation, producing a periodically excited electric field along the Ag NWs. This electric field then interfered with the femtosecond laser field, creating strong localized heating effects, which melted the Ag NW and GO, leading to mechanical bonding between the two. The formation of these heterostructures was attributed to the transfer of plasmon energy from the Ag NW to the adjacent GO surface. Since the connection efficiency of the nanowires is closely related to the specific location and the polarization direction of the laser, FDTD simulations were conducted to model the electric field distribution on the surface of Ag NW and GO structures under different laser polarization directions, varying the lengths and diameters of the nanowires. Finally, the resistance changes of the printed Ag NW paths on the GO thin film after femtosecond laser irradiation were investigated. It was found that laser bonding could reduce the resistance of the Ag NW-GO heterostructures by two orders of magnitude, further confirming the formation of the junctions. Full article

This study focused on investigations of FeCo and FeNi nanowires prepared by template-assisted electrodeposition in polycarbonate membranes. Nanowires with a diameter of 100 nm and length of 6 µm were grown at different cathodic potentials and electrolyte compositions. Scanning electron microscopy images revealed densely packed arrays of continuous nanowires with smooth surfaces without visible porosity, regardless of the applied potential. Chemical analysis of nanowires pointed out weak sensitivity of chemical composition on the electrodeposition potential in the case of FeCo nanowires, in contrast to FeNi nanowires, where the increase of the cathodic potential resulted in higher Ni content. X-ray diffraction studies showed polycrystalline structure for all samples indicating B2 phase (Pm-3m) with isotropic growth of FeCo nanowires and FeNi₃ phase with a preferential growth along [111] direction in the case of FeNi nanowires. The peak broadening suggests a fine crystalline structure for both FeCo and FeNi materials with average crystallite sizes below 20 nm. Magnetic studies indicated an easy axis of magnetization parallel to the nanowire axis for all FeCo nanowires and potential-dependent anisotropy for FeNi nanowires. The present studies thus suggested the feasibility of producing segmented nanowires based on FeNi alloys, while poor chemical sensitivity to the applied potential was observed for the FeCo system. Full article

Copper nanowires (Cu NWs) are considered a promising alternative to indium tin oxide (ITO) and silver nanowires (Ag NWs) due to their excellent electrical conductivity, mechanical properties, abundant reserves, and low cost. They have been widely applied in various optoelectronic devices. In this study, Cu NWs were synthesized using copper chloride (CuCl₂) as the precursor, monoethanolamine (MEA) as the complexing agent, and hydrated hydrazine (N₂H₄) as the reducing agent under strongly alkaline conditions at 60 °C. Notably, this is the first time that MEA has been employed as a complexing agent in this synthesis method for Cu NWs. Through a series of experiments, the optimal conditions for the CuCl₂–MEA–N₂H₄ system in Cu NWs synthesis were determined. This study revealed that the presence of amines plays a crucial role in nanowire formation, as the co-ordination of MEA with copper in this system provides selectivity for the nanowire growth direction. MEA prevents the excessive conversion of Cu(I) complexes into Cu₂O octahedral precipitates and exhibits an adsorption effect during Cu NWs formation. The different adsorption tendencies of MEA at the nanowire ends and lateral surfaces, depending on its concentration, influence the growth of the Cu NWs, as directly reflected by changes in their diameter and length. At an MEA concentration of 210 mM, the synthesized Cu NWs have an average diameter of approximately 101 nm and a length of about 28 μm. To fabricate transparent conductive films, the Cu NW network was transferred onto a polyethylene terephthalate (PET) substrate by applying a pressure of 20 MPa using a tablet press to ensure strong adhesion between the Cu NW-coated mixed cellulose ester (MCE) filter membrane and the PET substrate. Subsequently, the MCE membrane was dissolved by acetone and isopropanol immersion. The resulting Cu NW transparent conductive film exhibited a sheet resistance of 52 Ω sq⁻¹ with an optical transmittance of 86.7%. Full article

This study investigates the thermal pinning and depinning behaviors of vortex domain walls (VWs) in constricted magnetic nanowires, focusing on the influence of intrinsic magnetic properties on VW stability under thermal stress. Using micromagnetic simulations, we analyze the roles of saturation magnetization (Ms), uniaxial magnetic anisotropy (Ku), and nanowire geometry in determining VW thermal stability. The modeled nanowire has dimensions of 200 nm (width), 30 nm (thickness), and a 50 nm constriction length, chosen based on the dependence of VW formation on nanowire geometry. Our results show that increasing Ms and K_u enhances VW pinning, while thermal fluctuations at higher temperatures promote VW depinning. We demonstrate that temperature and magnetic parameters significantly impact VW structural stability, offering insights for designing high-reliability nanowire-based memory devices. These findings contribute to optimizing nanowire designs for thermally stable, energy-efficient spintronic memory systems. Full article

With an ultrahigh aspect ratio and a similar chemical composition to the biomineral in bone and tooth, ultralong hydroxyapatite nanowires (UHAPNWs) exhibit a meritorious combination of high flexibility, excellent mechanical performance, high biocompatibility, and bioactivity. Despite these exciting merits, the rapid and green synthesis of UHAPNWs remains challenging. In this work, we have developed an environment-friendly, rapid, and highly efficient synthesis of ultrathin UHAPNWs by the microwave-assisted calcium oleate precursor hydrothermal method using biogenic creatine phosphate as the bio-phosphorus source. Owing to the controllable hydrolysis of bio-phosphorus-containing creatine phosphate and the highly efficient heating of microwave irradiation, ultrathin UHAPNWs with a homogeneous morphology of several nanometers in diameter (single nanowire), several hundred micrometers in length, and ultrahigh aspect ratios (>10,000) can be rapidly synthesized within 60 min. This effectively shortens the synthesis time by about two orders of magnitude compared with the traditional hydrothermal method. Furthermore, ultrathin UHAPNWs are decorated in situ with bioactive creatine and self-assembled into nanowire bundles along their longitudinal direction at the nanoscale. In addition, ultrathin UHAPNWs exhibit a relatively high specific surface area of 84.30 m² g^–1 and high ibuprofen drug loading capacity. The flexible bio-paper constructed from interwoven ibuprofen-loaded ultrathin UHAPNWs can sustainably deliver ibuprofen in phosphate-buffered saline, which is promising for various biomedical applications such as tissue regeneration with anti-inflammatory and analgesic functions. Full article

Paper is a thin nonwoven material made from cellulose fibers as the main raw material together with some additives. Paper is highly flammable, leading to the destruction of countless precious ancient books, documents, and art works in fire disasters. In recent years, researchers have made a lot of efforts in order to obtain more durable and fire-retardant paper. Owing to the successful synthesis of ultralong hydroxyapatite (HAP) nanowires as a new kind of inorganic nanofiber material, it becomes possible to develop a new kind of super-durable and fire-resistant paper. Recently, the authors’ research group prepared a new kind of fire-resistant “Xuan paper” consisting of ultralong HAP nanowires. In this article, the super-durable fire-resistant “Xuan paper” based on ultralong HAP nanowires and the traditional Xuan paper based on cellulose fibers were evaluated by the accelerated aging method for 1200 days at 105 °C in air, which is the equivalent of 10,000 years of natural aging in the ambient environment. The aging mechanism of the traditional Xuan paper was further investigated by studying the fiber length/width and their distributions, morphology, infrared spectroscopy, thermogravimetric analysis, H–nuclear magnetic resonance spectra, and C–nuclear magnetic resonance spectra of cellulose fibers before and after the accelerated aging. The durability, properties, and mechanism of the fire-resistant “Xuan paper” based on ultralong HAP nanowires during the accelerated aging were studied. The experiments reveal the reasons for the deteriorated properties and reduced durability by aging of the traditional Xuan paper based on cellulose fibers, and the mechanism for the super-durability and excellent performances of the fire-resistant “Xuan paper” based on ultralong HAP nanowires during the accelerated aging process. Full article

In this work, we present an experimental approach for monitoring the temperature of submicrometric, real-time operating electrical circuits using luminescence thermometry. For this purpose, we utilized lanthanide-doped up-converting nanocrystals as nanoscale temperature probes, which, combined with a highly sensitive confocal photoluminescence microscope, enabled temperature monitoring with spatial resolution limited only by the diffraction of light. To validate our concept, we constructed a simple model of an electrical microcircuit based on a single silver nanowire with a diameter of approximately 100 nm and a length of about 50 µm, whose temperature increase was induced by electric current flow. By driving electric current only along one half of the nanowire, we created a dual-function microstructure, where one section is a resistive heater, while the other operates as a radiator. Such a combination realistically reflects the electronic circuit and its thermal behavior. We demonstrated that nanocrystals distributed around this circuit allow for remote temperature readout and enable precise monitoring of the thermal energy propagation and heat dissipation processes, which are crucial for designing and developing highly integrated electronic on-chip devices. Full article