High Performance Fiber Research Articles

A >20-W, linearly polarized single-frequency continuous-wave all-fiber laser at ∼1540 nm

We have developed both theoretically and experimentally an all polarization-maintaining fiber-based master oscillator power amplifier (MOPA) system, which allows for amplifying the single-frequency continuous-wave (CW) fiber laser to >20 W without compromising the laser intensity noise (−110 dBc/Hz@ relaxation oscillation peak) at the specific wavelength of ∼1540 nm. The experimental results agree well with the simulated results. To the best of our knowledge, this is the first demonstration of a ∼1540-nm single-frequency all fiber laser and reaching such a high-power level. The amplified laser features a narrow linewidth of ∼1.4 kHz and a spectral side-mode-suppression ratio of >38 dB, even as the laser wavelength is tuned from 1538.216 nm to 1540.616 nm. It is believed to be the narrowest laser linewidth realized in the <1550-nm wavelength band of an Erbium-Ytterbium co-doped fiber MOPA system. The all polarization-maintaining configuration of the MOPA ensures the amplified laser linearly polarized with the polarization extinction ratio of >22 dB and power root mean square fluctuations of <0.2 %@1h. This high-performance single-frequency fiber laser is expected to be an ideal pump source in the spin-exchange relaxation-free (SERF)-based atomic sensors after second harmonic generation.

Composite fabrics: Typological - exploratory study for permanent tensile structures in Ecuador

Tensile structures represent a notable evolution of construction materials, from their incipient construction using fabrics made with natural fibers to fabrics developed with high-performance synthetic fibers, which show the transformation of engineering and the design of new materials. The purpose of this document is to explore the use of composite fabrics in permanent tensile structural systems in Ecuador. Exploratory descriptive research is carried out, which identifies the types of application through a systematic classification. The results obtained focus on the characteristics of the use of tensile structures, construction region and detail of the technical, mechanical and physical characteristics, from the structural element approach in tensioned systems.

Tailoring structural, thermal, and optical properties of Tm3+-doped borotellurite glasses through Bi2O3 incorporation for optical fiber construction

This research investigates the influence of bismuth oxide (Bi2O3) on the structural, thermal, and optical properties of thulium (Tm3+) ion-doped borotellurite glasses, aiming to optimize materials for optical fiber construction. Melt-quench method was employed for glass preparation. XRD spectra indicated that all the synthesized glass samples exhibit an amorphous structure. By methodically increasing the Bi2O3 content to 0.1 molar fraction, significant improvements were observed in the glass matrix. These improvements include increased optical band gaps and decreased Urbach energy, indicative of reduced structural disorder and enhanced homogeneity. which are crucial for minimizing optical losses in fiber optics. Infrared (IR) spectroscopy analysis revealed that this optimal Bi2O3 content leads to denser, more ordered glass structures with an increase in bridging oxygens and a reduction in non-bridging oxygens, contributing directly to the observed improvements in optical properties. Additionally, thermal analysis highlighted a notable enhancement in the thermal stability of the glasses, highlighting their suitability for enduring variable temperature conditions and ensuring durability in optical fiber infrastructure. The findings support for the potential of these doped borotellurite glasses in advancing the development of robust, high-performance optical fibers capable of withstanding environmental challenges.

On the role of water in regulating the mechanics of collagen fibers

The mechanical properties of collagen fiber–based materials have garnered considerable attention owing to their application in various hydration environments. Herein, we conducted a comprehensive investigation on the mediatory role of water in the mechanical properties and structure of collagen fibers. Lower hydration levels are conducive to the mechanical strength, particularly the tensile and tear properties, and reduce the softness of collagen fibers as well as the D-period and the lateral spacing between collagen molecules. Atomic force microscopy measurements indicate that lower hydration levels also enhance the roughness, adhesion force and lateral forces between collagen fibers. Theoretical calculations further reveal that the hydration level regulates weaker components of water-mediated interactions, such as electrostatic and van der Waals forces, which dominate the resistance against mechanical shock. Our findings provide valuable insights into the role of water in regulating the mechanical behaviour of collagen fibers, thereby contributing to the development of novel high-performance collagen fiber materials.

Microstructure evolution and excellent electromagnetic wave absorption performance of SiBCN fibers

In this work, SiBCN fibers with excellent electromagnetic wave (EMW) absorption performance were fabricated using electrospinning technology, followed by curing, pyrolysis, and heat treatment. Microstructure evolution and EMW absorption performance of SiBCN fibers after heat treatment at 1200–1600 °C were investigated. After heat treatment at 1200 °C, the conductive turbostratic C was precipitated from amorphous SiBCN fibers, resulting in minimum reflection loss (RLmin) reaching −63 dB and efficient absorption bandwidth (EAB) reaching 5.2 GHz. While turbostratic C and nano-SiC grains were simultaneously precipitated from SiBCN fibers heat treated at 1400 °C, and the RLmin reached −67 dB. The excellent EMW absorption performance of SiBCN fibers was mainly attributed to the synergistic effect of conductive loss, dipole polarization, and interfacial polarization. This work can guide the fabrication of high-performance EMW-absorbing ceramic fibers.

Preparation of chitin twisted fiber and its functional applications

Chitin has garnered significant attention due to its renewable, biocompatibility and biodegradability, while its practical application seriously hindered as the functionality of chitin itself can no longer meet people's increasing requirements for materials. Here, an effective method is successfully built for high-performance chitin fibers fabrication through a multi-step strategy that involved chemical pre-crosslinking, followed by wet-twisting and wet-stretching techniques, combined with physical cross-linking. The as-prepared chitin fiber exhibited a smooth surface, adjustable diameter, and mechanical strong properties (144.6 MPa). More importantly, functional chitin fiber with magnetic or conductive abilities can be easily obtained by spraying Fe3O4 particles or Ag nanowire on the chemical pre-crosslinking chitin gel film before stretching and twisting. The doped functional inorganic particles exist in a continuous ribbon structure in the fiber reduced the decrease in material strength caused by uneven particles dispersion, resulting 88.4 % of stress and 91.6 % of strain retention. This work not only bestow invaluable insights into the fabrication of functional chitin fibers but also provide a novel approach to solve the problem of poor compatibility between organic and inorganic composite materials.

The Disperse Dyeing of Polyetherimide Fibers Using Orthogonal Array (Taguchi) Design

Polyetherimide (PEI) fibers are classified as high-performance fibers due to their notable characteristics, including chemical resistance, heat resistance, and flame resistance. However, the amorphous structure and intrinsic dyeability of polyetherimide (PEI) fibers set them apart from other high-performance fibers. The fibers possess considerable potential due to their remarkable performance features and are utilized in a wide range of industries, containing fashion and technical textiles, for varied purposes. The present work utilized the Orthogonal Array Taguchi method to systematically improve the dyeing process parameters for fabric samples made of polyetherimide (PEI). The use of a systematic methodology enabled effective experimentation and enabled the determination of the most favorable values of factors, while simultaneously reducing the utilization of resources. The study involved conducting rigorous experiments to evaluate the influence of several parameters on the color strength, tensile qualities, and washing fastness properties of the fabric samples. Furthermore, the utilization of the Taguchi approach facilitated the anticipation of these pivotal fabric properties by considering certain parameters. The objectives of this research encompass not only the progression of textile industry, but also the provision of beneficial perspectives for augmenting the caliber and efficacy of PEI fabrics in various applications.

Cost-effective preparation of pre-oxygenated PAN fiber composite SiO2 aerogel felt with excellent mechanical and thermal insulation properties

Silica aerogel is an attractive thermal insulation material due to its low thermal conductivity, light weight and non-combustible inorganic properties, but its inherent brittleness and high production cost hinder its practical application on a large scale. Herein, the high-performance pre-oxidized polyacrylonitrile fiber composite silica aerogel felt (PPAF-SiO2) was successfully prepared by a cost-effective combustion drying technique for the first time. The results show that the PPAF-SiO2 has the feature of lightweight, good flexibility, and its heat resistance, hydrophobicity, and specific surface area are significantly improved. Due to the further polymerization of fiber structure molecules caused by combustion, the tensile strength of the PPAF-SiO2 is increased by 81.9 % to 1.71 MPa. More importantly, due to the high proportion of silica aerogel in felt, its thermal conductivity can be reduced to 0.02 W/(m·K), which is lower than most aerogel composite materials. Moreover, the thermal insulation performance of the PPAF-SiO2 was further confirmed by the infrared thermal imager from room temperature to 300 ℃. In addition, the innovative drying mechanism based on the combustion flame model was proposed. Finally, compared with traditional physical drying technologies in terms of drying time and drying conditions, the combustion drying technology shows great advantages in drying efficiency, energy consumption and equipment investment, which greatly reduces production costs. The combustion drying technology opens up a promisingly method for high efficiency, low energy consumption, and low cost preparation of silica aerogel composites.

Kilohertz-linewidth and low-threshold single-frequency all-fiber laser utilizing self-developed Nd3+-doped fluoro-sulfo-phosphate fiber

Compared to Nd: YAG lasers, Nd3+-doped fiber lasers offer superior beam quality, compactness, and heat dissipation, especially in generating single-frequency lasers, which holds great promise for applications in optical atomic clocks, quantum computing, and high-precision bio-photonic imaging. In this study, theoretical simulations of the local environment and experimental analyses on the luminescent characteristics of what we believe to be a novel Nd3+-doped fluoro-sulfo-phosphate (FSP) laser glass were performed to mitigate the concentration and hydroxyl quenching effects. Based on that, a highly Nd3+-doped (4 mol%) FSP fiber with a large emission cross-section (3.24 × 10−20 cm2), wide bandwidth (33.7 nm), long lifetime (354 µs), and high gain coefficient (4.24 dB/cm) was designed. Utilizing this fiber, a 1065 nm SFFL with a low pump threshold of 18 mW, a narrow linewidth of 6.5 kHz, and a 0.9 µm compact all-fiber laser were demonstrated, highlighting the potential of Nd3+-doped FSP fiber in high-performance fiber lasers.

Multifunctional, efficient, and durable composites of conductive PMIA/Ag membrane

Developing high-efficiency electromagnetic interference (EMI) shielding composite membranes along with additional functionalities to extend the application scenarios is highly desirable for the next generation electronic devices. Here, we report an ultrathin and flexible EMI shielding materials with sensitive Joule heating and outstanding infrared stealth performance was fabricated from poly-m-phenylene isophthalamide (PMIA) and Ag nanoparticles (AgNPs) through an innovation and simplicity method of electrospinning and electroless plating. Profiting from a continuous three-dimensional (3D) conductive network, the final membrane achieves an outstanding EMI shielding effectiveness (SE) of 100.51 dB (in X-band), a remarkable Joule heating properties with a fast thermal response and low driving voltage (<0.5 V), and an outstanding infrared stealth with a low infrared emissivity (0.28). Meanwhile, the prepared composite membrane demonstrates stable EMI SE even after water washing, continuous bending, and heating treatment. This work integrates high-performance fiber PMIA, characterized by high heat resistance, flame retardancy, self-extinguishing properties, and chemical resistance, with functions such as EMI shielding, infrared stealth, and autonomous thermal management. It has great development potential if utilized in specialized combat uniforms under harsh conditions.

Autonomous self-healing strategy for flexible fiber lithium-ion battery with ultra-high mechanical properties and volumetric energy densities

The development of wearable devices urgently requires flexible, lightweight, and high-performance power solutions. Flexible fiber batteries are flexible and deformable, which holds great potential in this field. However, it still face significant challenges in achieving excellent electrochemical performance and good mechanical properties. Herein, we developed a new method for preparing flexible fiber lithium-ion batteries by surface etching and in-situ chemical cross-linking strategies using direct ink writing-based 3D printing technology. On the one hand, the surface of graphene oxide undergoes oxidation and etching to form pores. This unique pore structure provides additional channels for ions, which increases the ion transmission rate. On the other hand, polyvinyl alcohol/sodium metaborate is introduced into the printing ink/coagulation bath. In-situ chemical cross-linking occurs during the printing and curing process, which exhibits self-healing properties. The flexible fiber electrode has excellent strain (∼30 %) at the macro level, and the assembled fiber lithium-ion battery exhibits impressive volumetric energy density (157.9 mWh cm−3), which exceeds previously reported flexible fiber batteries. And it is also integrated into wearable smart watches for use in daily life. This work proposes an innovative method to fabricate high-performance flexible fiber electrodes, which is of great significance for promoting the development of future portable/wearable electronics.

Gel electrolyte based high-performance fiber battery

Gel electrolyte based high-performance fiber battery

Effect of CNT Oxidation on the Processing and Properties of Superacid-Spun CNT Fibers.

Spinning fibers from carbon nanotube (CNT)/superacid dispersions has emerged as a promising strategy for industrial-scale production of high-performance CNT fibers (CNTFs). The oxygen content and types of functional groups on CNT surfaces significantly influence dispersion, assembly processes, and fiber properties. In this study, Tuball-SWCNTs were purified and oxidized at varying levels. The dispersion behavior of CNTs with different oxidation levels in chlorosulfonic acid was systematically observed, and the mechanical properties of fibers spun from these dispersions were compared. By adjusting the dispersion concentration, highly oriented CNTFs were produced with a specific strength of 1.03 N/tex, a tensile strength of 1.59 GPa, and an electrical conductivity of 3.58 MS/m. Further investigations indicated that oxygen-containing functional groups decrease the coagulation rate, increasing the maximum draw ratio during spinning and improving CNT alignment in the fibers. Molecular dynamics simulations demonstrated that these functional groups (-OH, -COOH) enhance load transfer between CNTs through hydrogen bonding. This specific strength is the highest achieved using Tuball-SWCNTs for superacid-spun fibers, surpassing previous works due to the oxidation-controlled coagulation rate, enhanced fiber orientation, and improved load transfer via hydrogen bonding. This study provides insights for designing and optimizing high-performance CNTFs.

Mechanical Properties of Cotton and High-Performance Fiber Blended Denim Fabrics for Motorcycle Protective Clothing

Mechanical Properties of Cotton and High-Performance Fiber Blended Denim Fabrics for Motorcycle Protective Clothing

Experimental and numerical investigations on tensile failure mechanism and load-bearing capacity of expansion anchors under pull-through failure mode in HPSFRC

Pull-through(PT) is a unique failure mode of torque-controlled expansion(TCE) anchor after being pulled out from concrete. No universal design formula is available for predicting tensile bearing capacity of anchor of PT mode. In normal concrete(NC), PT failure usually occurs at large embedment depths(Hef), which is uncommon in the field and received less attention than the concrete breakout failure. However, due to the improved mechanical performance of the substrate, the PT mode dominates for anchors in high-performance steel fiber reinforced concrete(HPSFRC) substrate (even at small Hef). In this study, to study the PT mode in HPSFRC, the results of 34 PT failures from previous tests, including testing scenarios with different anchor diameters(D), Hef, and fiber contents(vf), are analyzed. The cracking morphology and load-bearing capacity distribution of PT mode are elaborated. Further, finite element models(FEM) of anchor pullout behavior in HPSFRC is established, which accurately identified different failure modes. The calculated Nu by FEM agree well with the tested Nu. The difference in damage domain between different failure modes is mainly reflected in the unloading stage. Parametric analyses were conducted on pre-tightening torque(Tini), Hef, D, sleeve length(Lsleeve), anchor cone width, anchor cone length(Lcone), and vf to study their influences on Nu of PT mode. Except for Lsleeve and Lcone, which do not affect Nu, changes in other factors can cause linear or nonlinear changes in Nu. The non-linear relationship between Nu and experimental parameters is formulated. Accordingly, a new prediction model that can accurately predict Nu of PT mode for anchors in HPSFRC is developed, of which calibration factors are derived using probability functions.

Twisting process of basalt fibers in water: The effects of water on microscopic structure and spinning property

Basalt fibers (BFs) are eco-friendly and natural high-performance fibers, specifically engineered for use in protective clothing, offering significant benefits. However, the inherent brittleness of this inorganic fabric not only poses challenges in processing but also renders it uncomfortable for wear. Consequently, there is an urgent need to modify BFs to enhance their torsional property and skin compatibility. Herein, we immersed BFs in water and twist them into yarn to investigate the effects of water erosion on BFs, specifically focusing on its impact on fiber structure and spinning performance. Under water's erosion, the BFs experienced ion-exchange reactions that compromised the silica framework, leading to a significant rise in both static and dynamic friction coefficients 162.5 % and 233.3 %, respectively, and a 1.53-fold improvement in torsional performance. The process of twisting in a water bath facilitated better fiber bundling, yielding a more compact yarn structure. This compaction reduced the occurrence of burrs following friction and enhanced both tensile and loop strength. At the fiber level, we utilized a simple water erosion method to enhance the twisting performance of basalt filament. This approach circumvents the disadvantages of large etching modification damage and poor sizing fastness, offering a novel method for the preparation of basalt twisted yarn.

Synergistic effect of spinning drawing and preoxidation stretching on the orientation structure of mesophase pitch carbon fibers

Mesophase pitch carbon fiber has shown remarkable prospects in specialty carbon material. The mechanical properties of mesophase pitch carbon fiber (CF) cannot be precisely controlled because of the difficulty of forming process regulation. The early forming of carbon fiber (precursor fiber (PF) and pre-oxidation fiber (OF)) is difficult to regulate, such as carbon microcrystal and carbon layer texture, while cause the irreversible growth of carbonization process. Herein, a synergy strategy of spinning drawing and preoxidation stretching is developed to optimize orientation structure, eliminate morphology defects and improve mechanical properties. A synergistic effect of superior spinning drawing and suitable preoxidation stretching is beneficial to adjust the more order rearrangement of carbon microcrystals. The tensile strength of carbon fibers with spinning drawing and preoxidation stretching is increased by 1.7 times, and their defects are reduced by 40%. The results show that the excellent mechanical property of carbon fiber is contributed by the extrusion stress caused by high oxidation crosslinked surface layer under tension, and the micro-flow and rearrangement of carbon microcrystals induced by extrusion stress. A mechanical strengthening mechanism of carbon fiber is proposed, which provides guidance for high-performance mesophase pitch carbon fiber.

Kinetics on thermal soaking of mesophase pitch at processing temperature and its influence on the derived carbon structure

Mesophase pitch (MP) is an attractive precursor for tailoring high-performance carbon fibers due to its aromatic hydrocarbons mesogenic components that self-assemble into highly ordered microstructures. Relating processing conditions to the evolution of MP microstructure and its inheritance in carbon materials remains a challenge. This work quantitatively determined the kinetics of mesogenic aggregation in MP at spinning temperatures for the first time. Polarized optical microscopy tracked domain size changes in MP during 1–24 h thermal soaking. Analysis using an exponential growth model revealed nonlinear growth kinetics with an activation energy of just 39.3 kJ·mol−1, suggesting mesogenic aggregation is facile at processing temperatures compared to mesophase formation. Prolonged thermal soaking promoted microcrystalline development in derived carbon fibers, evident from increased crystallite stacking and reduced interlayer spacing. Relating microstructural evolution in the MP to the resulting carbon fiber structure provides new insights to tailor carbon materials for applications. This work revealed the kinetics of MP at its processing temperature, provides a valuable insight into the future optimization of processing conditions for MP based carbon materials.

Plastic hinge length in reinforced HPFRCC beams and columns

The use of ductile concrete materials such as High Performance Fiber Reinforced Cementitious Composites (HPFRCCs) within plastic hinge regions of structural components has garnered research interest in order to improve the seismic resistance of reinforced concrete structures. While experimental and numerical results appear promising in reducing component damage and probability of system level collapse, accurate nonlinear analysis tools capable of capturing the influence of axial load well into a component’s inelastic regime is needed. In this study, a series of 180 high fidelity numerical simulations of HPFRCC beam–column elements are simulated and used to calibrate new plastic hinge length expressions for concentrated and distributed plasticity models for use in system level structural analysis. The numerical models cover a range of HPFRCC material properties, reinforcement ratios, shear span lengths, and axial load levels. The ability of the newly developed expressions to predict component inelastic rotations are subsequently compared to hinge length expressions in the literature and the inelastic rotations of 47 experimental components. The results of this study provide new insights into the effects of axial load on the plastic hinge behavior of HPFRCC components, significantly improves on the accuracy of past plastic hinge length expressions allowing for more accurate modeling of HPFRCC component responses and system level behavior.

A convenient swelling-permeation strategy for constructing high-performance fiber reinforced composite hydrogel

Ligaments are a unique wet biological tissue with ultrahigh tensile strength, modulus, and flexural flexibility. Developing artificial materials with similar properties is important but challenging. Herein, we present a novel swelling-permeation strategy for preparing high-performance fiber reinforced composite hydrogels capable of mimicking the ligaments. Through pre-swelling the meta-aramid fibers in good solvents to vastly boost their porosity, large amounts of pre-gel solution can permeate into the pores of fibers during the soaking process. After the polymerization of pre-gel solutions inside and around fibers, the interpenetrating networks form directly between the hydrogel matrix and meta-aramid fibers. The mechanical interlock and abundant hydrogen bond of interpenetrating networks enable the generation of strong interfacial binding between hydrogels and fibers. In consequence, the as-prepared composite hydrogel has high tear resistance (405.30 kJ/m2), tensile strength (125 MPa), and modulus (218 MPa), superior to previously reported composite hydrogels. Meanwhile, the resulting composite hydrogels have outstanding flexibility and good biocompatibility, thereby exhibiting great potential as artificial ligaments. The preparation method proposed in this paper is simple, controllable, and scalable, which opens up the possibility of large-scale production of artificial ligaments.