High Performance Fiber Research Articles

High-performance dual-core photonic crystal fiber polarization beam splitter based on gold-titania composite film coating

Abstract A novel gold-titania composite film-coated dual-core photonic crystal fiber polarization beam splitter (GT-DC-PCF PBS) is proposed for the first time. The titania film and gold film are sequentially deposited on the inner wall of the central air hole to improve the polarization splitting performance and enhance the adsorption strength between the gold film and the optical fiber. Based on the mode coupling theory and surface plasmon resonance effect, the transmission characteristics of x-polarization (X-pol) and y-polarization (Y-pol) odd and even modes in the near-infrared band are analyzed by finite element method. Meanwhile, the variation of coupling length and coupling length ratio for X-pol and Y-pol light under different PCF structural parameters at the wavelength of 1550 nm are also studied to optimize the performance of PBS. The results show that at the 1550 nm communication window, the extinction ratio of the PBS is up to -175.82 dB for the polarization splitting length of 2.76 mm, with an operating bandwidth of 179 nm and a maximum insertion loss of 0.23 dB. This paper aims to propose a novel design method to improve the performance of DC-PCF PBS, which has profound guiding significance for the development of high-performance PBS.

A comparison of the effect of oxygen partial pressure on microstructural evolution of PAN fibers during industrial carbon fiber production line at different altitudes

Understanding and regulating the oxidative stabilization behavior of polyacrylonitrile (PAN) precursor fibers are critical subjects of high-performance carbon fiber production technologies. Here, we performed continuous stabilization and carbonization of PAN fibers at industrial carbon fiber production lines in different locales (different oxygen partial pressure in atmosphere), and investigated the microstructural evolution of the fibers with a systematically analysis at different stages. Influence of oxygen partial pressure in oxidative stabilization atmosphere on tensile modulus of the obtained carbon fibers was obvious. Oxygen diffused into PAN fibers during oxidative stabilization, more homogeneous and crosslinked structures generated under higher oxygen partial pressure atmosphere, and gave the stabilized fibers lower skin-core ratio. The graphite layers gradually generated in the subsequent carbonization stages, and the gathered graphite layers transformed into graphite microcrystalline, the wide-angle x-ray diffraction (WAXD) demonstrated that higher oxygen partial pressure conditions contributed to the generation of higher crystallite preferred orientation and bigger crystallite size, Raman spectroscopy also confirmed the obtained carbon fibers with higher oxygen partial pressure conditions possessed more ordered graphite structures. Thus, relatively higher oxygen partial pressure in air gave the stabilized fibers more crosslinked structures, and contributed to the formation of high-performance carbon fibers.

Characterization of heat- and alkali-resistant feruloyl esterase from Humicola insolens and application in the production of high-strength kraft straws.

The application of feruloyl esterase (FAE) in biobleaching can effectively hydrolyze the feruloyl ester bond between hemicellulose and lignin, thereby partially disrupting the dense structure of the fiber, reducing the use of chemical reagents, and obtaining high-performance pulp fibers. Here, we successfully expressed the thermostable alkaline feruloyl esterase from Humicola insolens (H. insolens) in Pichia pastoris GS115, with an enzyme activity yield of 2.36 ± 0.21U/mL. The highest activity of FAE for the hydrolysis of ethyl ferulate was observed at pH7.5 and 70°C. It retained about 56% of its maximum activity in the pH range of 11.0. After being incubated at 50-55°C for 1h, it retained 70.05% of its maximum activity. The addition of bio-enzyme pretreatment before chemical bleaching can reduce chemical reagents by 20%, result in a 10.64% reduction in kappa value, and increase the delignification rate of the pulp by 6.36%. In addition, the surface of the enzyme-treated pulp showed rougher broom-like fiber filaments, and the viscosity of the enzyme-pretreated pulp (ECP) before chemical treatment increased by 131.51% compared to the chemically treated pulp (CP), further indicating that the enzyme-pretreated pulp had higher pulp strength.

Structural application of high-performance fibre reinforced cementitious composites

Structural application of high-performance fibre reinforced cementitious composites

Enhancing high-order harmonic mode-locking in Er/Yb-Doped fiber lasers with sub-MHz fundamental frequency via optoacoustic resonance

We present an experimental study of a long Er/Yb-doped fiber ring laser with a low fundamental frequency of 0.678 MHz. By solely adjusting the quarter-wave plate in the polarization controller, we uncovered a series of reproducible laser generation regimes. Among these, multiple soliton bunches were harmonically mode-locked to low-order cavity harmonics (from the 3rd to the 8th). Notably, we also identified a regime featuring a stable soliton train harmonically mode-locked to the 472nd cavity harmonic at 320 MHz. This regime demonstrated exceptional harmonic mode-locking stability, with a supermode suppression level of 49 dB corresponding to the timing jitter on the order of a few picoseconds. We attribute this remarkable stability to an exact optoacoustic resonance between the laser repetition rate and the fiber eigen acoustic mode frequencies, specifically identified as R06 and TR2,15. These findings represent a significant advancement in high-performance fiber laser operation, particularly in enhancing the stability of lasers with sub-MHz fundamental frequencies capable to generate regular pulses with much higher repetition rates.

Constructing ultrahigh capacitance (Co,Mn)(Co,Mn)2O4/Ni(OH)2 electrode for boosted all-solid-state fiber asymmetric supercapacitors

To meet the practical demands of flexible fiber-shaped supercapacitors (FSSCs) for wearable electronics, it's crucial to develop electrodes with both high energy density and flexibility. In this work, an ultrahigh capacitance (Co,Mn)(Co,Mn)2O4/Ni(OH)2 (CMO/Ni(OH)2) fiber electrode is designed. The (Co,Mn)(Co,Mn)2O4 (CMO) nanosheets possessing large specific surface area and enriched active sites, which can be served as nano-substrate for the electrodeposition of Ni(OH)2. This special structure facilitates the exposure of more electroactive sites and accelerate rapid electrons transfer, resulting in boosted electrochemical performance. Benefiting from these advantages, the area capacitance of the CMO/Ni(OH)2 electrode is up to 4787.6 mF cm−2 at 1 mA cm−2, which is approximately 15 times higher than that of the CMO (311 mF cm−2), and 6.7 times higher than that of the Ni(OH)2 (718 mF cm−2). Coupled with activated carbon (AC) electrode, the assembled all-solid-state CMO/Ni(OH)2//AC FSSCs demonstrate a high energy density of 89.45 μW h cm−2 at 1505 μW cm−2, along with great flexibility and stability. Moreover, these devices can be integrated into clothes, and electronic watch, serving as an energy supply. This work offers a novel approach to designing high-performance fiber electrode for wearable flexible energy storage devices.

Mesoscopic Simulation on Centrifugal Melt Electrospinning of Polyetherimide and Polyarylethernitrile

Polyetherimide (PEI) and polyarylethernitrile (PEN) are high–performance materials for various applications. By optimizing their fiber morphology, their performance can be further enhanced, leading to an expanded range of applications in carbon fiber composites. However, developing processes for stable and efficient fiber production remains challenging. This research aims to simulate the preparation of high–performance ultrafine PEI or PEN fibers using electrospinning. A mesoscopic simulation model for centrifugal melt electrospinning was constructed to compare and analyze the changes in molecular chain orientation, unfolding, fiber diameter, and fiber yield under high-voltage electrostatic fields. The simulation results showed that temperature and electric field force had a particular impact on the diameter and yield of PEI and PEN fibers. Changes in rotational speed had negligible effects on both PEI and PEN fibers. Additionally, due to their different molecular structures, PEI and PEN, which have different chain lengths, exhibit varied spinning trends. This study established a mesoscopic dynamic foundation for producing high-performance ultrafine fibers and provided theoretical guidance for future electrospinning experiments.

Aqueous Photoiniferter Polymerization of Acrylonitrile.

Polyacrylonitrile (PAN) is a key industrial polymer for the production of carbon fiber for high-strength, lightweight composite material applications, with an estimated 90% of the carbon fiber market relying on PAN-based polymers. Traditionally, PAN synthesis is achieved by conventional radical polymerization, resulting in broad molecular weight distributions and the use of toxic organic solvents or surfactants during the synthesis. Additionally, attempts to improve polymer and processing properties by controlled radical polymerization methods suffer from low monomer conversions and struggle to achieve molecular weights suitable for producing high-performance carbon fiber. In this study, we present an aqueous photoiniferter (aqPI) polymerization of acrylonitrile, achieving high monomer conversion and high PAN molecular weights with significantly faster kinetics and dispersity control when compared to traditional methods. This approach allows for the unprecedented control of polymer properties that are integral for downstream processing for enhanced carbon fiber production.

High-Performance Fiber Optic High-Frequency Cantilever Acoustical Transducer Based on PET Film

High-Performance Fiber Optic High-Frequency Cantilever Acoustical Transducer Based on PET Film

Lignin–Poly(vinyl alcohol) Compound from Acetalization Synthesis as a Reinforcing Filler for High-Performance Gel-Spun Fibers

Lignin–Poly(vinyl alcohol) Compound from Acetalization Synthesis as a Reinforcing Filler for High-Performance Gel-Spun Fibers

On exploiting the architecture of annual ring growth for developing a new class of bio-inspired composites

Inspired by several biological structures available in nature, bio-inspired composite structures are evidenced to exhibit a noteworthy enhancement in various mechanical and multi-physical performances as compared to conventional structures. This article proposes to exploit the architecture of annual ring growth of the stems of trees for developing a new class of bio-inspired composites with enhanced static and dynamic performances, including deflections, stresses, strain energy, and vibration. Concentric circular annual-ring geometries are considered where each layer of concentric circular fibers is analogous to the growth per annum of trees. The annual rings are modeled in a finite element-based computational framework by idealizing each layer as a composite of graphite fibers and epoxy matrix under different boundary conditions. The ratio of deflection to weight and frequency to weight of bio-inspired and traditional composites are compared by considering different parameters such as the number of annual rings, layers, and supporting stiffeners. The numerical results reveal that the proposed bio-inspired composites can enhance and modulate the static and dynamic properties to a significant extent, opening new design pathways for developing high-performance fiber network composites.

Stretchable and High-Performance Fibrous Sensors Based on Ionic Capacitive Sensing for Wearable Healthcare Monitoring.

Electronic textiles with remarkable breathability, lightweight, and comfort hold great potential in wearable technologies and smart human-machine interfaces. Ionic capacitive sensors, leveraging the advantages of the electric double layer, offer higher sensitivity compared to traditional capacitive sensors. Current research on wearable ion-capacitive sensors has focused mainly on two-dimensional (2D) or three-dimensional (3D) device architectures, which show substantial challenges for direct integration with textiles and compromise their wearing experience on conformability and permeability. One-dimensional (1D) stretchable fiber materials serve as vital components in constructing electronic textiles, allowing for rich structural design, patterning, and device integration through mature textile techniques. Here, a stretchable functional fiber with robust mechanical and electrical performances is fabricated based on semi-solid metal and ionic polymer, which provided a high stretchability and good electrical conductivity, enabling seamless integration with textiles. Consequently, high-performance stretchable fiber sensors are developed through different device architecture designs, including pressure sensors with high sensitivity (7.21kPa-1), fast response (60ms/30ms), and excellent stability, as well as strain sensors with high sensitivity (GF = 1.05), wide detection range (0-300% strain), and excellent sensing stability under dynamic deformations.

High-performance dual-core conjoined tube negative curvature fiber polarization beam splitter

High-performance dual-core conjoined tube negative curvature fiber polarization beam splitter

Conversion of waste denim fabrics into high-performance carbon fiber anodes for sodium-ion batteries

Conversion of waste denim fabrics into high-performance carbon fiber anodes for sodium-ion batteries

Pull-out behavior and failure mechanism of steel expansion anchors in high-performance steel fiber reinforced concrete(HPSFRC)

Past research on the pull-out performance of anchors mainly focuses on normal concrete(NC) concretes. New design methods are needed for the pull-out performance of anchors in the concretes of new cementitious materials with high strength and toughness. Accordingly, the pull-out behavior of torque-controlled expansion anchor(TCE) in high-performance steel fiber reinforced concrete(HPSFRC) concrete with different fiber content and installation conditions(embedment depth and anchor diameter) was investigated. The focus was on the failure modes, crack morphology, and load-displacement behavior(including pull-out load-bearing capacity, anchorage stiffness, and anchorage toughness). The addition of fibers leads to increased load-bearing capacity and toughness, reduced stiffness, and all failure modes exhibited ductile cracking and sufficient tensile ductility. Both diameter and depth had a positive impact on load-bearing capacity. A broader database based on literature and this study was analyzed for further exploration of the effects of fibers. The accuracy of predicting load-bearing capacity was compared between two empirical models(concrete capacity design-CCD and Toth models) and the proposed modified model. The CCD model greatly underestimates capacity, and the Toth model is unsuitable for high fiber content(exceeds 2.0 %) HPSFRC scenarios. The modified model showed the best bearing capacity prediction for anchors on HPSFRC concretes, with a mean ratio of predicted values to experimental values reaching 1.01–1.08 and a coefficient of dispersion below 15.0 %.

Extraction of high-quality moso bamboo fibers by enzyme/alkali synergistic mechanism

As an emerging non-wood resource, moso bamboo has attracted extensive attention because of its short growth cycle and high holocellulose content. However, the internal structure of moso bamboo is more compact than that of wood, leading to higher chemical consumption during the pulping process, which greatly reduces the quality of the extracted fibers. Herein, an innovative pulping system including enzymes and alkali is proposed to achieve higher-quality extraction of moso bamboo fibers. Benefiting from the synergistic effects of high-temperature and alkali-resistant cellulase, xylanase, and laccase, supplemented with alkaline pulping, adequate retention and softening of moso bamboo fibers were ultimately achieved. The sample treated with an enzyme/alkali system resulted in a relative increase in fiber length of 7.19 % and a 31.26 % increase in beating efficiency over alkaline pulping. In addition, the tensile index and tearing index of the paper treated with the enzyme/alkali system reached 50.17 N·m·g−1 and 9.12 mN·m2·g−1, which were 22.52 % and 20.53 % higher than those of the alkaline pulping, respectively. This work provides new insights into the production of high-performance moso bamboo fibers and paper with low energy and alkali consumption.

Current research status of high-performance UHMWPE fiber: A review

In the relentless evolution of technological innovation, the incorporation of engineered materials across numerous sectors is becoming increasingly widespread. Among them, ultra-high molecular weight polyethylene (UHMWPE) fiber, as a novel type of engineered material, has emerged as a critical hot topic in industries such as aerospace, national defense, and new energy due to its exceptional physical and chemical properties. This article attempts to introduce the characteristics of UHMWPE fibers, including their advantages and areas for enhancement, to provide researchers with a comprehensive overview and research trajectory of UHMWPE. Moreover, this article succinctly elucidates the preparation methodologies and advances of UHMWPE fibers, encompassing mainstream dry and wet spinning methods, revealing their research trajectories, pivotal positions, and practical significance in the realm of engineered materials. In summary, this review briefly discusses the research overview and recent advances in UHMWPE fibers, which contribute to accelerating comprehensive and sustainable progress in this field.

Low-cost and rapid preparation of high-performance carbon fiber reinforced ceramic matrix composites by molding-in situ densification

Carbon fiber reinforced ceramic matrix composites (CFCMCs), demonstrated huge demand of braking and transmission systems for heavy-loading equipment. However, high production cost, cumbersome preparation process and long preparation cycle severely limited its application and industrialization in the defense industry. In this work, a molding-in situ densification process was proposed to prepare AlN-modified CFCMCs under the synergistic effects of Al and Al2O3 fillers, facilitating a significant reduction in the preparation steps and treating temperature. The existence of active Al fillers was conducive to inducing the formation of Al-Si alloy melt and increasing contact area between Si and C to reduce the temperature of the Si-C reaction and promote the densification of composite materials. Meanwhile, the addition of Al2O3 effectively limited long-range flow of the alloy melt, further inhibiting severe volume deformation of the composites and the generation of large pores. When the maximum heat treatment temperature reached 1300 °C, the preparation cycle of AlN-modified CFCMCs reduced as low as 23–28 h after the molding-in situ densification process, which was roughly decreased by a 50 % drop. The compressive and flexural strength of AlN-modified CFCMCs achieved 308.51 MPa and 115.68 MPa, respectively. This molding-in situ densification strategy provided a pathway toward to achieve low-cost and rapid preparation of high-performance CFCMCs for the scale-up application in the fields of defense and military industry.

Synthesis and spinnability of vinyl-grafted carbon nanotubes /polycarbosilane precursor with high ceramic yield

Silicon carbide (SiC) fiber is a high-performance ceramic fiber mainly prepared by the polymer-derived ceramics (PDC) method. However, balancing the precursor's ceramic yield and spinnability is challenging in the preparation process. Herein, we proposed a new strategy, chemical bonding with PCS to form a high cross-linked network structure, utilizing the flexibility and high aspect ratio within MWCNTs. As a result, based on the spinnable PCS (57.58 %), only the incorporation of 0.05 wt% MWCNTs increase the ceramic yield by 21.66 %–70.05 % and 1 wt% MWCNTs achieved as high as 81.44 % when pyrolyzed at 900 °C. Moreover, the hybrid precursors showed good spinnability, except for the 1%-MWCNTs/PCS. In addition, the presence of chemical bonding and cross-linking structures has been thoroughly proven, and the mechanism behind the increase in ceramic yield has been further explored. MWCNTs occupied cross-linking sites and formed cross-linked structures to effectively reduce weight loss during thermal cross-linking in the 300–500 °C temperature range, thereby increasing ceramic yield. The increment of spinnable PCS in the ceramic yields can effectively reduce the preparation cost and enhance the performance of the SiC fibers using the PCS method.

Spatiotemporal dissipation dynamics: a route to high-beam-quality and high-peak-power spatiotemporal mode-locked fiber lasers

Spatiotemporal mode-locking (STML) opens a new avenue for implementing high-energy, high-peak-power mode-locked fiber oscillators. However, the compromised beam quality poses a critical limitation to their broader applications. This study presents a method for enhancing the beam quality of STML fiber lasers by employing spatiotemporal dissipation involving the quenching and reabsorption effects of multimode erbium-doped fibers. The proposed technique introduces spatiotemporal saturable absorption, achieving high beam quality without the stringent conditions required for Kerr beam self-cleaning (BSC). Integrating spatiotemporal dissipation with Kerr BSC, we demonstrate an all-anomalous-dispersion Er-doped STML fiber laser, which produces solitons with 6.7 nJ pulse energy (the intracavity solitons with 25.8 nJ pulse energy and >52.8kW peak power), sub-500 fs pulse duration, and beam quality with M x 2/M y 2=1.23/1.20. To our knowledge, it is a record peak power for 1.5 µm band soliton lasers. Additionally, the approach enables the generation of noise-like pulses with M x 2/M y 2=1.04/1.13. This work not only advances our understanding of spatiotemporal dissipation dynamics in STML fiber lasers, but also paves the way toward high-performance STML fiber lasers, rendering them very attractive for applications.