Composite Fibers Research Articles

Influence of Breakages of Reinforcing Elements of a Composite Orthotropic Stay Rope on Its Stress-Strain State

The purpose of research is to justify a calculation method for a stay rope of composite fiber structure with a breakage in fiber continuity. Research methodology is in constructing and solving a deformation model of a composite fiber stay rope with continuity breakage of one of its fibers. The calculation method of a stress-strain state of a stay rope of composite fiber structure considering the breakage of one of its fibers is established. The scientific novelty of research is in determining that the length of manifestation of a local disturbance of a stress-strain state of composite stay rope is proportional to a square root of a ratio of tensile modulus of a reinforcing element material and shear modulus of an elastic material that connects them. The practical value of the research is in that the calculation method allows reasonable prediction of a tractive capacity loss of a stay rope as a result of breakage of any of its reinforcing elements. The known value of residual tractive capacity allows reasonable selection of a safety margin for a stay rope, which ensures a sufficient level of reliability of a cable-stayed bridge.

Carbon Nanofiber/Polyaniline Composite Aerogel with Excellent Electromagnetic Interference Shielding, Low Thermal Conductivity, and Extremely Low Heat Release

Abstract The rapid development of communication technology and high-frequency electronic devices has created a need for more advanced electromagnetic interference (EMI) shielding materials. In response to this demand, a study has been conducted to develop multifunctional carbon nanofibers (CNFs)/polyaniline (PANI) aerogels with excellent electromagnetic interference shielding, flame retardancy, and thermal insulation performance. The process involved freeze-drying of electrospun CNFs and PANI nanoparticles followed by in situ growth PANI to coat the CNFs, creating the core–shell structured CNFs/PANI composite fiber and its hybrid aerogels (CP-3@PANI). The interaction between PANI and aniline (ANI) provides attachment sites, allowing additional ANI adsorption into the aerogel for in situ polymerization. This results in PANI uniformly covering the surface of the CNFs, creating a core–shell composite fiber with a flexible CNF core and PANI shell. This process enhances the utilization rate of the ANI monomer and increases the PANI content loaded onto the aerogel. Additionally, effective connections are established between the CNFs, forming a stable, conductive three-dimensional network structure. The prepared CP-3@PANI aerogels exhibit excellent EMI shielding efficiency (SE) of 85.4 dB and specific EMI SE (SE d−1) of 791.2 dB cm3 g⁻1 in the X-band. Due to the synergistic flame-retardant effect of CNFs, PANI, and the dopant (phytic acid), the CP-3@PANI aerogels demonstrate outstanding flame-retardant and thermal insulation properties, with a peak heat release rate (PHRR) as low as 7.8 W g⁻1 and a total heat release of only 0.58 kJ g⁻1. This study provides an effective strategy for preparing multifunctional integrated EMI shielding materials.

Preparation of bio‐based polyamide 56/chitosan heavy metal adsorbing nanocomposite fibers by electrospinning

AbstractElectrospinning technology can produce nanofibers with extremely high specific surface area. Bio‐based polyamide 56 (PA56) was combined with chitosan (CS) to prepare PA56/CS composite nanofibers. An in vitro mineralization experiment was conducted to obtain a super hydrophilic composite fiber (PA56/CS‐HAP) with hydroxyapatite deposited on the surface. The adsorption performance of the composite fiber (PA56/CS‐HAP) was evaluated by the adsorbent dosage, solution pH value, and adsorption kinetics. The curves obtained after fitting the kinetics and adsorption isotherms show that the adsorption behavior under pH = 6 is more consistent with the Langmuir adsorption model. The adsorption capacity in a 100 mg L−1 Pb2+ environment is more than 5 times that of 10 mg L−1. Bio‐based PA56/CS static‐spun nanocomposite fibers prepared by in vitro mineralization have great potential in environmental protection, sensors, chemical engineering, and other fields.Highlights PA/CS fibers were prepared by electrospinning. Hydroxyapatite was deposited by in vitro mineralization technique. PA/CS‐HAP fiber achieves super hydrophilic effect. The adsorption capacity of PA/CS‐HAP in 100 mg L−1 Pb(II) reached 27.5 mg g−1. After fitting, the adsorption process is consistent with Langmuir adsorption.

Synergistic removal of tetracycline hydrochloride by nano-MnOx/NCF composite fiber (MNCs) catalysts via heterogeneous peroxymonosulfate (PMS) activation

Nnano-MnOx/NC composite fibers (MNCs) has been successfully prepared by the calcination treatment of Mn-Nitrilotriacetic acid (Mn-NTA) fibers precursor that are synthesized by hydrothermal method. The in-situ formed nano-MnOx is adhered to the N doped carbon nanofibers. The as-prepared MNCs fibers are employed as catalyst to decompose tetracyclines hydrochloride (TCH) by activating peroxymonosulfate. Compared with other MNCs catalyst, the synergistic effect of Mn3O4 and N-doping carbon in MNC-700 during the catalytic process endows MNC/PMS system with the superior mineralization capacity for TCH degradation with less amount of catalyst and PMS. Quenching experiments and EPR tests confirm that the oxidative degradation of TCH involves radical and non-radical route. Multiple reactive oxygen species (SO4−, OH, and 1O2) contribute to the degradation of TCH. Our research offers an effective strategy for the TCH degradation through PMS activation using the composite fibers of MnOx and N doped carbon.

Assessment of fiber alignment through combined driven oscillatory and directional magnetic fields in matrix with similar rheological behavior to cementitious materials

In this paper a novel method to improve the effectiveness of the aligning of fibers used as reinforcement in Fiber Reinforced Cementitious Composites (FRCC) through directional homogeneous magnetic fields is proposed. A combination of homogeneous magnetic fields, oscillatory and directional, are assessed as a new method for fiber aligning which increase the aligning index and mechanical efficiency index of the fiber in cementitious composites. Fresh cementitious materials present a Static Yield Stress (T0s), which must be overpassed to allow the rotation of the fiber immersed in the matrix. To reduce the T0s of the matrix, oscillatory magnetic fields (OMF) are applied firstly, as they generate a vibrational strain of the fiber. Later, fibers are aligned through a directional magnetic field which finds a lower opposition of the rheological torque. The fibers are subjected to an orientation rotation caused by the magnetic field, which is caused by a magnetic torque. This torque is opposed by two torques, one of rheological origin (Yield stress and viscosity) and another of inertial type (geometry and mass distribution of the fiber). The rheological torque is the torque that opposes to the rotation of the fiber and is a function of the rheological properties of the matrix. Two pairs of Helmholt coils have been used in this research, to be able to generate orthogonal magnetic fields to directional magnetic fields. When the OMF was generated, one of the pair of coils were connected to the net, with a frequency of 50 Hz. OMF was performed in 0.64mT-1.25mT-2.18mT. To evaluate its effectiveness each of them was applied in periods of time of 2–5–7–10 seconds before the directional magnetic field of 30 mT. To assess the method steel fibers has been submerged in a metaphor fluid to reproduce the rheological properties of cement materials. The initial and final angles of the batch of fibers have been determined through photography and Computer-aided design. The results obtained shown that the use of OMF increases the alignment index up to 35 % and the mechanical efficiency rate up to 24.35 % in the batches studied. The research followed also showed that previous vibration can be applied during periods of 5 seconds, with the same pair of coils that for aligning but also the use of the two pair of coils can be used simultaneously.

Research on the Performance of Carbon Fiber Composite Railings for Ships

With the development of the shipbuilding industry, the requirements for the safety and corrosion resistance of ship structural components are becoming increasingly high. Most of the components used in traditional ships are made of steel, which cannot meet the requirements of corrosion resistance and safety for existing ships. In order to improve the structural safety and corrosion resistance of ship railings, as well as their lightweight requirements, this article proposes a lightweight design for ship railing structures based on the advantages of carbon fiber composite materials, such as light weight, high strength, and high modulus, on the basis of the existing traditional metal railing structures for ships. Based on the anisotropy of carbon fiber composite fibers, the characteristics of overlapping/weaving structures, and the influence of the interface between carbon fiber composite materials and metal materials on the strength of ship railing structures, a finite element simulation model of carbon fiber composite materials is established. By setting constraints such as volume fraction, stress, strain, displacement,etc.in the given simulation model, the layout of materials in the optimization results is used to guide the design of the structure, and the size parameters of the ship railing barrel are optimized for structural optimization. Thus achieving lightweight design of ship railings and meeting the requirements for lightweight, safety, service life, and corrosion resistance of ship structural components.

High-filler content electrospun fibers from biodegradable polymers and hydroxyapatite: Toward improved scaffolds for tissue engineering.

One of the key challenges in tissue engineering area is the creation of biocompatible scaffolds that support cell growth and mimic the structural and mechanical properties of native tissues. Among various materials used for scaffold fabrication, composite materials based on biodegradable polymers reinforced with bioactive inorganic fillers have attracted significant attention due to their properties. One of the important problems with the preparation of composite electrospun fibers is the low filler content in the fiber. This study aims to select the best composition for electrospun polymer fibers in terms of potential application in tissue engineering. The effect of the viscosity of polymer solution/dispersion and filler content on the structure and properties of the fibers was determined. Morphology and filler content were compared. Series of electrospun composite fibers were fabricated from poly(ĺ-caprolactone) (PCL), poly(L-lactic acid) (PLLA) and hydroxyapatite (HAP), containing from 10 wt% to 40 wt% HAP. The properties of the resulting composites were studied using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and viscosimetry measurements. The addition of HAP to the polymer solution caused a significant increase in viscosity, but the results showed that it is possible to obtain composite electrospun fibers even with 40 wt% filler content. Scanning electron microscopy analysis shows randomly oriented electrospun fibers with an average diameter in the range of 3.8-8.5 ěm for solution and dispersion with high viscosity (1,210-2,000 mPa·s) and significantly larger diameters (approx. 12 ěm) for the PCL solution (326 mPa·s). It is possible to transform the composite dispersion from biopolymers and HAP into nonwoven fabrics at up to 40 wt% filler content. Due to their unique properties, such materials are promising for application in tissue engineering.

Self-healing polyurethane/cellulose nanocrystal composite fibers with fatigue and aging resistance for smart wearable elastic yarns

Self-healing polyurethane/cellulose nanocrystal composite fibers with fatigue and aging resistance for smart wearable elastic yarns

Graphene-Based Fiber Materials for Gas Sensing Applications: State of the Art Review

The importance of gas sensors is apparent as the detection of gases and pollutants is crucial for environmental monitoring and human safety. Gas sensing devices also hold the potential for medical applications as health monitoring and disease diagnostic tools. Gas sensors fabricated from graphene-based fibers present a promising advancement in the field of sensing technology due to their enhanced sensitivity and selectivity. The diverse chemical and mechanical properties of graphene-based fibers—such as high surface area, flexibility, and structural stability—establish them as ideal gas-sensing materials. Most significantly, graphene fibers can be readily tuned to detect a wide range of gases, making them highly versatile in gas-sensing technologies. This review focuses on graphene-based composite fibers for gas sensors, with an emphasis on the preparation processes used to achieve these fibers and the gas sensing mechanisms involved in their sensors. Graphene fiber gas sensors are presented based on the chemical composition of their target gases, with detailed discussions on their sensitivity and performance. This review reveals that graphene-based fibers can be prepared through various methods and can be effectively integrated into gas-sensing devices for a diverse range of applications. By presenting an overview of developments in this field over the past decade, this review highlights the potential of graphene-based fiber sensors and their prospective integration into future technologies.

Assessment of surface quality and damages induced during dry helical milling of hybrid composite fiber metal laminates

Abstract The present work investigates the effectiveness of helical milling for making holes with excellent surface quality in carbon fiber aluminum laminates (CARALL) under dry-cutting conditions. The impact of cutting speed and axial pitch on hole surface quality was analyzed. The findings show that axial pitch and cutting speed significantly impact surface roughness. Utilization of lower cutting speed (30 m/min) and axial pitch (0.1 mm/rev) results in material adhesion and feed marks, thus lowering the surface roughness. Nevertheless, the surface finish was enhanced by using higher levels of process variables. Surface defects like chip adhesions, deformation marks, and material smearing were observed. The orientation of the cutting edge with the fibers greatly influenced the surface morphology. Exposed fibers with varying lengths were noted when machining fiber layers oriented at 135°, thus creating an irregular surface. Scanning Electron Microscopic observation of the carbon fiber layers displayed a cleanly cut surface without fiber pullout and crack or interlayer burrs. Moreover, the holes in the CARALL were devoid of delamination/debonding for all the combinations of process variables. In general, results demonstrate the suitability of helical milling for processing holes with superior surface quality and satisfying the stringent requirements of the aircraft industries.

Structural-Functional Integrated Graphene-Skinned Aramid Fibers for Electromagnetic Interference Shielding.

Structural-functional integrated polymer fibers with exciting properties are increasingly important for next-generation technologies. Herein, we report the structural-functional integrated graphene-skinned aramid fiber (GRAF) featuring high conductivity, high strength, and light weight, which is weaved for efficient electromagnetic interference (EMI) shielding. Graphene was self-assembled onto the surface of aramid fibers through a dip-coating strategy using an aramid polyanion (APA) as the binder and the etchant. The molecular dynamics (MD) simulation results show that the binding energy of the APA-modified aramid chain and graphene (1.3 J/m2) is superior to that of the aramid chain and graphene (0.2 J/m2). The APA has a higher surface energy (55.2 mJ/m2) and can etch the fiber surface, forming grooves, which enables effective adsorption and self-assembly of graphene onto the fiber surface. The GRAF exhibits a high conductivity of 1062.04 ± 116.78 S/m, along with excellent strength (4.66 ± 0.16 GPa) and modulus (106.33 ± 8.21 GPa), outperforming most reported conductive composite fibers (e.g., natural fibers, polymer-based fibers, inorganic fibers, etc.). The weaved functional fabric using the structural-functional integrated GRAF shows an EMI shielding efficiency (SE) of up to 67.86 dB in the X-band and can rapidly heat up to 200 °C within 40 s at 12 V voltage. In addition, the GRAF fabric can maintain its electrical conductivity after a long-term washing, showing excellent washing resistance. This study demonstrates an effective method to fabricate structural-functional integrated materials and shows the promise of carbonene fibers for EMI shielding.

Polyvinyl Alcohol Nanofibers with Embedded Two-Dimensional Nanomaterials and Metal Oxide Nanoparticles: Preparation, Structural Characterization, and Biological Activity

Eco-friendly iron and manganese oxide nanoparticles (Fe2O3 and Mn2O3) were synthesized and integrated into graphene sheets to form uniform composites. These composites were then embedded in polyvinyl alcohol (PVA) fibers using electrospinning. Comprehensive characterization of the composites and the final composite fibers was conducted using XRD, FE-SEM, and FTIR to analyze their structural complexity and morphological differences. The antibacterial efficacy of the resulting PVA nanofibers was evaluated against Escherichia coli, which is a common pathogen in hospital environments. The results show a significant bactericidal effect against these bacteria, which highlights their potential in medical applications, such as functional bandages and wound dressings. This study paves the way for potential commercial applications of these nanofibers in healthcare settings.

Polyimide/zirconia composite fiber prepared via an in-situ polar adsorption-hydrolysis method with good compression resistance

A series of PI/ZrO2 composite fibers was prepared by the in-situ polar adsorption-hydrolysis method to improve compression properties. The influence of the ZrO2 shell on the surface, interface and compression properties of the PI fiber was evaluated through scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, microsphere debonding, monofilament tensile recoil, and multifilament composite compression. The results demonstrate a 50 % increase in the compressive strength of monofilament and a 16 % increase in composites. Additionally, effective modification of the surface properties of the fibers lead to a remarkable enhancement of 78 % in interfacial shear strength (IFSS). Moreover, improvements were also observed in both tensile strength and thermal stability of the monofilament. It provided a new technical way for the improvement of the interface property and compressive strength of organic fiber reinforced composites.

Washing Resistant Antibacterial PET Composite Fibers Fabricated by Melt Spinning

Washing Resistant Antibacterial PET Composite Fibers Fabricated by Melt Spinning

A Self-Oscillator Based on Liquid Crystal Elastomer Fiber Under Constant Voltage.

Self-oscillation is the phenomenon in which a system generates spontaneous, consistent periodic motion in response to a steady external stimulus, making it highly suitable for applications in soft robotics, motors, and mechatronic devices. In this paper, we present a self-oscillator based on liquid crystal elastomer (LCE) fiber under constant voltage. The system primarily consists of an LCE-liquid metal (LCE-LM) composite fiber, a metal mass sphere, and a straight rod featuring both conductive and insulating segments. Building upon an established dynamic LCE model, we derive the governing dynamic equations. Numerical calculations reveal two distinct motion regimes: a static regime and a self-oscillation regime. Furthermore, we provide the temporal behavior curves of electrothermal-induced contraction and tensile force, the phase trajectories variation curves of the equivalent driving force and damping force. These detailed studies elucidate that self-oscillation results from the contraction of the electrothermal-responsive LCE-LM fiber when the circuit is activated, with continuous periodic motion being sustained through the interplay between the metal mass sphere and a self-controlled dynamic circuit. We also investigate the threshold conditions necessary for initiating self-oscillation, as well as the key system parameters that influence its frequency and amplitude. Our self-oscillator demonstrates improved stability by reducing the effects of gravity and other disturbances. Additionally, the curved trajectory of the mass sphere can be achieved by replacing the straight rod with a curved one, resulting in a more flexible and easily controllable structure. Given these characteristics, a self-oscillator system based on LCE-LM fiber may be ideal for creating monitoring and warning devices, dynamic circuit systems, and for integrating actuators and controllers.

PEEK-PANI bi-functional oil-water separation membrane based on structural switchable wettability

Prewetting-induced switchable wettability materials demonstrate considerable potential for a diverse range of applications in comparison to traditional oil-water separation membranes including conventional special wetting materials, due to the distinctive advantages they offer. The current prewetting-induced switchable wettability materials are still constrained by the preparation strategy, separation performance and stability in practical application environment. This study presents a method for the preparation of PEEK/PANI bi-functional oil-water separation membranes by electrospinning and in-situ polyaniline growth. The controllable in-situ growth of PANI particles on PEEK fibers resulted in the formation of surface nano-micro structures, which enhanced the switchable underwater oleophobicity and underoil hydrophobicity of the membrane. The switching of wettability and the separation process is induced by prewetting in water or oil. The membranes display high permeability (maximum water flux of up to 8910 L⋅m−2⋅h−1) and separation efficiency (greater than 99.9 %) in gravity-driven oil-water mixtures/emulsion separation. PEEK-PANI composite fiber membranes demonstrate consistent separation performance in a range of corrosive or organic solvent environments due to the robust nature of the materials and the structural wettability This work presents a novel approach for the introduction of surface nano-micro structures and switchable structural wettability, as well as the production of high-performance multifunctional oil-water separation materials.

Pengaruh Penambahan Serat Pohon Bambu Ampel (Bambusa Vulgaris) pada Komposit Hybrid untuk Material Bumper Kendaraan Bermotor

Technological developments continue to increase in line with the times, producing various innovations that provide benefits to society, especially in the material sector. The use of a mixture of natural and synthetic fibers in composites (hybrid) has produced a stronger material, which can function as an alternative material for car bumpers. This research was carried out with the aim of determining the values ​​of impact toughness, tensile strength, and failure patterns that occur in the fracture cross section of the specimen through macro photographs. In this research, a hybrid composite was formed by combining ampelous bamboo fiber, fiberglass, and polyester resin. Variations in volume fraction applied include: 5%:25%:70%, 10%:25%:65%, and 15%:25%:60%. The specimens were formed according to ASTM E23 standards for impact tests and ASTM D638 for tensile tests. The results of the impact and tensile tests showed that the lowest value of impact toughness was 0.0744 J/mm² and tensile stress was 120.29 MPa. Meanwhile, the highest value for impact toughness was 0.0986 J/mm² and the tensile stress value was 147.65 MPa. Macro photo analysis of the fracture cross section is categorized as splitting in multiple areas and the fracture cross section also shows debonding and fiber pull out after the fracture occurred.

Electrospinning of LaB6/PEDOT:PSS/PEO Fiber Composites of Unique Morphologies.

We present a direct electrospinning fabrication technique for the manufacture of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/poly(ethylene oxide) (PEDOT:PSS/PEO) polymer fibers containing embedded cubic lanthanum hexaboride (LaB6) particles. We focus on the impact of relative humidity on the formation of uniform polymer fibers and show that a relative humidity of 5% is optimal, resulting in an average fiber thickness of 266 ± 88 nm. As the relative humidity is increased, the fibers contain beads as a consequence of Rayleigh instabilities. The addition of lanthanum hexaboride cubic particles to the polymer solution before electrospinning results in the encapsulation of the LaB6 particles inside the fibers. We investigate the effect of LaB6 particle size on morphology and observe that particles of ∼500 nm yield a fiber-cube-fiber morphology, while 2 μm particles result in fewer embedded cubes along the length of the polymer fibers. This phenomenon likely arises from electrodynamic interactions between the LaB6 particles in the polymer solution and the electric field lines generated during electrospinning between the spinneret and the collector. Our results display the versatility of the electrospinning technique in the fabrication of unique polymer/hexaboride composite fibers.

Shape parameter of Weibull size statistics is a potential indicator of filler geometry in SiO2 reinforced polymer composites

In a previous study [Physica A, 625 (2023), 129026], a relationship between the filler size distribution and the filler geometry of SiO2 particle reinforced polymer composites has been reported. It has been experimentally demonstrated that the size of hollow and solid SiO2 particles disperse in polymer matrix follows Weibull statistics with shape parameter at 2 and 3, respectively. This mechanism has not yet been verified in the one-dimensional (1D) case. In this paper, we study the length distribution of glass fibers in polymer composites. Our results show that the previous theory still holds for the 1D case. Thus, shape parameter of Weibull size statistics could be a potential indicator of filler geometry in SiO2 reinforced polymer composites. This interesting mechanism can be explained by the scaling nature behind the Weibull statistics. Our study has thus shed new light on the evolution of filler geometry during the fabrication process of polymer composites, and should be useful for the related fields.

Multiferroicity and Semi‐Cylindrical Alignment in Janus Nanofiber Aggregates

Abstract1D multiferroic fibers are known to exhibit attractive characteristics, including enhanced magnetoelectric (ME) coupling compared to thin film and bulk architectures. A comprehensive understanding of composite fibers, however, has been hindered by the complexity of their structure, leading to limited reports. Here, clear and strong ME coupling is experimentally detected in a composite Janus nanofiber aggregate using second harmonic generation (SHG) polarimetry under different magnetic field orientations. The observation of such a pronounced effect using an all‐optical method has not been previously reported in multiferroic fibers. A series of global fits is performed to the SHG polarimetry results to investigate the behavior of nanofibers within an aggregate. We find the magnetically assembled fibers exhibit semi‐cylindrical alignment as well as the expected lengthwise alignment despite variations in size and composition from fiber to fiber. The ME coupling and the semi‐cylindrical alignment seen in SHG are further corroborated via X‐ray diffraction under similar magnetic field conditions. These findings contribute to the development of complex composite and multifunctional devices using multiferroic nanostructures as building blocks, even those with inhomogeneous shapes and geometries.