Fabrication Of Fibers Research Articles

A numerical analysis of the blood-based Casson hybrid nanofluid flow past a convectively heated surface embedded in a porous medium

Abstract The analysis of the fluid flow with the energy transfer across a stretching sheet has several applications in manufacturing developments such as wire drawing, hot rolling, metal extrusion, continuous casting, paper production, and glass fiber fabrication. The current examination presents the hybrid nanofluid flow past a convectively heated permeable sheet. The ferrous oxide (Fe3O4) and Gold (Au) nanoparticles have been dispersed in the blood. The significances of thermal radiation, inclined magnetic field, and space-dependent heat source have been observed in this work. The modeled equations are presented in the form of partial differential equations and reformed into the set of ordinary differential equations (ODEs) by using the similarity substitution. The Matlab built-in package (bvp4c) is employed to resolve the transform nonlinear set of ODEs. The significance of flow constraints versus the velocity and temperature profiles is demonstrated in the form of Figures and Tables. The numerical outcomes for the physical interest quantities are presented in tables. It has been perceived from the results that raising the angle of inclination from 0° to 90° reduces both the velocity and energy profile. The escalating values of Eckert number, constant heat source, and space-dependent heat source factor accelerate the temperature profile. The velocity and temperature distributions are very effective in the cases of hybrid nanofluid (Au–Fe3O4/blood) when compared to nanofluid (Au/blood). The skin friction and rate of heat transfer are very effective in the cases of hybrid nanofluid (Au–Fe3O4/blood) when compared to nanofluid (Au/blood).

Fabrication of continuous SiOC ceramic fibers by polyethylene oxide assisted sol-gel method

The continuous SiOC ceramic fibers were fabricated by a novel polyethylene oxide (PEO) assisted sol-gel method. The precursor fibers were prepared by a solution which viscosity and composition can be regulated. The solution with excellent spinning performance was constituted by the optimized composition of tetraethyl orthosilicate, methyltrimethoxysilane, sucrose, and PEO. The effects of the pyrolysis temperatures and C/Si ratios on the microstructure and mechanical properties of SiOC ceramic fibers were investigated. After pyrolysis at 1200 °C, the tensile strength of SiOC ceramic fibers was 182.5 MPa and the surface was uniform and dense. Furthermore, XPS and FTIR analysis confirmed the formation of Si–O–Si and Si–C bonds, demonstrating the existence of SiO3C after pyrolysis at 1200 °C. The oxidation and high-temperature resistance of the SiOC ceramic fibers were also investigated. The results showed their ability to withstand heat treatment at 1000 °C in air and 1200 °C in Ar. The continuous SiOC ceramic fibers have broad prospects for commercial application as the thermal protection and high temperature resistant material. And the novel PEO-assisted sol-gel method can be employed to fabricate various ceramic fibers.

Microwave-assisted solid-state pretreatment for fabrication of hemp fibres using ethanolamine at low temperature

Conventional methods faced challenges in pretreating natural cellulose fibres due to their high energy consumption and large wastewater drainage. This research devised an efficient solid-state pretreatment method for pretreating hemp fibres using ethanolamine (ETA) assisted by microwave (MW) heating. This method produced a notable removal rate of lignin (85.4 %) with the highest cellulose content (83.0 %) at a high solid content (30 %) and low temperature (70 °C). Both FT-IR and XRD analyses indicated that the pretreatment did not alter the structure of cellulose within the hemp fibres but increased crystallinity as the CrI increased from 84 % in raw hemp fibre to 89 % in pretreated fibre. As a result, it produced hemp fibres with impressive fineness (4.6 dtex) and breaking strength (3.81 cN/dtex), meeting the requirement of textile fibre. In addition, an improvement in glucose concentration (15.6 %) was observed in enzymatic hydrolysis of the MW pretreated hemp fibres compared to the fibres pretreated without MW. Furthermore, the FT-IR and NMR data confirmed that the amination of lignin occurred even at low temperature, which contributed to the high lignin removal rate. Thus, this study presents a potentially effective energy-saving, and environmentally sustainable solid-state method for pretreating hemp fibres.

Fabrication of SiC(OAl) and SiC(Al) fibers by melt-spinning, UV curing, thermolysis and sintering of photo-sensitive polyvinylaluminocarbosilane

SiC fiber is an important structural material in high-temperature extreme environments and nuclear energy applications. Oxidation and electron irradiation are main curing methods for the fabrication of industrial SiC fibers. In this work, a photo-sensitive polyvinylaluminocarbosilane (PVACS) is facilely prepared by blending polyaluminocarbosilane (PACS) and 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane (D4Vi), which can be melt spun, cured by ultraviolet irradiation at room temperature. After thermal pyrolysis and sintering, the SiC(OAl) fibers with oxygen content of 8.84 wt% and C/Si ratio of 1.34, the SiC(Al) fibers with oxygen content of 0.29 wt% and C/Si ratio of 1.03 are achieved. The cured mechanism and the structural evolution from the precursor fiber to the final ceramic fibers is investigated. The results show that homopolymerization of D4Vi is the main curing mechanism in addition to the β-addition of hydrosilylation. Different from the typical oxidative curing, the oxygen in the fibers mainly comes from D4Vi. At about 800 ℃, the SiAlxOy phase, the SiCxOy phase and free carbon are formed. At 1200 ℃, the Al-C bonds possibly in Al4C3 are formed. At around 1600 ℃, Al may exist mainly in the form of Al4O4C, and the amorphous carbon phase changes into crystalline graphitic structure. Meanwhile, a lot of mesopores and macropores in the SiC(OAl) fibers are formed due to thermal decomposition of the SiCxOy phase. However, at 1800 ℃, the SiC(Al) fibers densify again due to the formation of Al2OC and Al4SiC4 phases, which also inhibit the growth of β-SiC and favor the formation of α-SiC.

Retraction of “Fabrication and Characterization of Wood Fiber Reinforced Polymer Composites”

Retraction of “Fabrication and Characterization of Wood Fiber Reinforced Polymer Composites”

Super-elastic microstructured triboelectric fibers and textiles fabricated by extrusion and thermal drawing for smart-home applications

Flexible and wearable textile-based triboelectric nanogenerators (TENGs) have attracted extensive attention in wearable electronics owing to their ability to convert waste mechanical energy from human motion into electrical energy. However, the performances of TENGs are lower than those of planar/film configurations due to the complex fiber fabrications and limited mechanical freedom. In this work, we demonstrate an extrusion method combined with thermal drawing (ETD method) for continuous and scalable triboelectric fiber fabrication, providing longitudinal uniform fibers for hundreds of kilometers. Based on the ETD method, super-elastic microstructured triboelectric fibers (SMTFs) were fabricated, consisting of hollow elastomeric and liquid metal cores (EGaIn). The SMTFs showed excellent superelasticity with clear and uniform microstructures. The fibers could withstand strain up to 1800% and exhibited excellent electrical output performance. Utilizing a single fiber as the medium for triboelectric energy collection, the average open circuit voltage and instantaneous power density are respectively up to 210 V/m and 21 μW/m with a 40 MΩ external load resistance. The SMTFs could also be woven into deformable textiles with high electrical outputs up to 160 V, 10 μA, and 50 nC. In addition, the SMTFs-based textiles were further demonstrated as completely soft and stretchable components for self-powered sensing in smart home applications.

Experimental investigation on the internal stress of bismuth-doped fiber and its effect on the noise figure of Bismuth-doped fiber amplifier.

The noise figure (NF) of a fiber amplifier is one of the key measures of amplification performance, which characterizes the quality of the amplified signal. Residual stresses are inevitably generated during the manufacturing process of optical fibers, and this can lead to changes in the refractive index (RI) distribution of the fiber. Further, the change in RI distribution causes the mode-field characteristics of the fiber to change as well, and this ultimately has an impact on the NF performance of the amplifier. However, until now, there have been fewer studies on the effect of residual stress on the NF of the fiber amplifiers. In this work, we took a commercial single-mode bismuth-doped fiber (BDF) as an example and used a self-developed stress test device to measure its residual stress and refractive index distribution and compare it with that of a passive fiber. We also comprehensively compared the distribution of residual stress and refractive index of the fiber at different pump powers and pump wavelengths. Finally, we performed numerical simulations of the bismuth-doped fiber amplifier (BDFA) based on the BDF under the theoretical mode field area and BDF after the expansion of the mode field area due to stresses to compare the NF performance. The results demonstrate that: the entire cross-section (core and cladding) of the BDF exhibits tensile stress (>0 MPa), where the residual stress at the core of the BDF is nearly 9.8 MPa higher than that of the passive fiber; The residual stress makes the mode-field area of the BDF expand by 26.7% compared with the theoretical values, which ultimately makes the NF of the BDFA rise from 4.6 dB to 4.7 dB; The stress at the BDF core is exacerbated by pump excitation, where it is elevated by about 26% and 5% compared to vacancy at 1240 nm and 1310 nm pumps, which is most likely attributed to thermal effects. Therefore, it is necessary to consider the effect of residual stresses in the fabrication of optical fibers to better achieve the radius of the expected indicators. This work contributes to the better development of O-band BDFAs, especially for pre-simulation of the actual performance of BDFAs with a practical reference.

Design and fabrication of 125-μm standard cladding diameter heterogeneous 8-core fiber with ultra-low crosstalk for C-band transmission

Design and fabrication of 125-μm standard cladding diameter heterogeneous 8-core fiber with ultra-low crosstalk for C-band transmission

A novel eco–friendly solid–state degumming method for extraction of hemp fibers

Hemp represents a valuable resource of natural fibers on account of its environment favorable characteristics and excellent fiber quality. To fabricate hemp fibers, the traditional alkaline boiling degumming is used in the industry, which consumes a lot of water and generates a substantial amount of wastewater. In the present study, a novel eco–friendly solid–state degumming method was developed by using ethanolamine (ETA). The ETA degumming exhibited a high lignin removal rate (87.5%) at a high solid loading (30%), decreasing water consumption by 33.3%. Moreover, the ETA solution was readily reused up to five times without purification. The degummed hemp fibers possessed commendable fitness (4.2 dtex) and breaking strength (3.75 cN/dtex) without change of the crystalline cellulose structure. Besides, the lignin in wastewater was confirmed to be aminated, which is beneficial to the potential valorization of the by–product. Thus, the solid–state ETA degumming method holds significant potential for the fabrication of hemp fibers.

Design, Fabrication, and Characterization of Large Mode Area Inhibited-Coupling Guiding Hollow-Core Fibers

Design, Fabrication, and Characterization of Large Mode Area Inhibited-Coupling Guiding Hollow-Core Fibers

Fabrication and Mid-Infrared Laser Transmission Performance of Ultra-Low Loss Chalcogenide Glass Fibers

Fabrication and Mid-Infrared Laser Transmission Performance of Ultra-Low Loss Chalcogenide Glass Fibers

Using polyethylene terephthalate bottle waste as a viable precursor for the synthesis of unsaturated polyester resin in fabrication of jute fibre reinforced composites

The present research effort employs glycolysed polyethylene terephthalate (PET) bottle waste as a precursor for the synthesis of unsaturated polyester resin (rUPR). This resin is then used for manufacturing composites that are reinforced with jute fibres using the sheet moulding compound technique. The limited crosslinking of styrene in the rUPR was elucidated using a combination of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) analysis. The elevated exothermic reaction energy of 1152 kJ and the clearly identifiable peak observed at 1620 cm−1 in the Fourier Transform Infrared (FTIR) spectrum provided substantial evidence for this phenomenon. Additionally, the X-ray diffraction (XRD) analysis indicated that the recycled unsaturated polyester resin (rUPR) demonstrated a higher level of amorphous nature This observation can be attributed to reduced viscosity and enhanced ductility of rUPR. The utilisation of the rUPR as a matrix material has shown significant effectiveness in enhancing the tensile and flexural properties of composites reinforced with jute fibres. Thereby, the objective of this research is to develop a thermoset resin using recycled polyethylene terephthalate (rUPR) waste material for identification its suitability in manufacturing composites with jute fibres as reinforcement.

Improved mechanical properties of environmentally friendly jute fibre reinforced metal laminate sandwich composite through enhanced interface

Natural plant based fibres are being increasingly used in sustainable fibre reinforced composite applications in order to meet the demand of using environmentally friendly materials for composites. Fibre metal laminates (FMLs) are used in aerospace, automobile, marine and civil engineering applications, due to their excellent mechanical behaviors compared to traditional metals and their alloys. This study describes a novel fabrication of jute fibre reinforced aluminum metal laminates, using different jute fibre architectures (plain and twill fabric structures), wherein jute fibres were used in the skins and aluminum in the core layers. Jute fibres and aluminum sheets were chemically treated to enhance the compatibility and interfacial bonding at fibre-metals-matrix interfaces. FMLs were manufactured by hot pressing technique, after the application of wet lay-up process for the resin impregnation and they were further tested under tensile, flexural and impact loading conditions. While comparing results, the twill architecture showed improved tensile and flexural properties compared to plain fabric based FMLs. Chemical treatments on twill jute fibres and metal sheets further exceptionally enhanced the flexural properties (151 MPa flexural strength and 21.3 GPa modulus and they were increased by 186.5 % and 722.7 % respectively compared to the untreated jute fibre counterparts) of the laminates due to a significant improvement in the adhesion between the jute fibre and aluminum sheet after alkali treatment applied. Therefore, with these enhanced properties, jute based FML laminates can be used as sustainable composite materials in many structural applications.

Fibres-threads of intelligence-enable a new generation of wearable systems.

Fabrics represent a unique platform for seamlessly integrating electronics into everyday experiences. The advancements in functionalizing fabrics at both the single fibre level and within constructed fabrics have fundamentally altered their utility. The revolution in materials, structures, and functionality at the fibre level enables intimate and imperceptible integration, rapidly transforming fibres and fabrics into next-generation wearable devices and systems. In this review, we explore recent scientific and technological breakthroughs in smart fibre-enabled fabrics. We examine common challenges and bottlenecks in fibre materials, physics, chemistry, fabrication strategies, and applications that shape the future of wearable electronics. We propose a closed-loop smart fibre-enabled fabric ecosystem encompassing proactive sensing, interactive communication, data storage and processing, real-time feedback, and energy storage and harvesting, intended to tackle significant challenges in wearable technology. Finally, we envision computing fabrics as sophisticated wearable platforms with system-level attributes for data management, machine learning, artificial intelligence, and closed-loop intelligent networks.

Ni,S co-doped Cu dendrites decorated with core-shell architecture assisted by MOF and Fe0.92Co0.08S nanoflakes on nanocellulose/graphene fibers for fabrication of flexible wire-type micro-supercapacitor.

One-dimensional micro-supercapacitors (1D micro-SCs) have been regarded as an efficient energy storage system to fulfill the ever-growing need for miniaturized electronics. Designing multi-dimensional nanoarchitectures on fibrous microelectrodes is an effective strategy to build a high-performance 1D micro-SC. In this work, Ni,S-doped Cu was firstly prepared on Cu wire as a micro-sized 1D current collector through Cu electrodeposition using a H2 bubble template and then co-doped with nickel and sulfur. Benefiting from the high electrical/thermal conductivity of Cu, and the highly electroactive sites of Ni and S as well as the 3D porous architecture, the deposited Ni,S-doped Cu provided a platform for growing active substances. Thereafter, cobalt carbonate hydroxide (CoCH) pine-like nanoneedle integrated ZIF-67 polyhedrons were synthesized on a foam-like skeleton and converted into NiMoCo-layered triple hydroxide (LTH)/Ni,S-doped Cu shish-kebab type nanoarrays by applying a hydrothermal method. Finally, Ni2Mo3N-CoN/Ni,S-doped Cu was prepared via nitridation. The potent interactions and synergy between components realized a well-organized hybrid nanoarchitecture consisting of dodecahedrons decorated on needle-like arrays within a 3D framework with rich redox properties, rapid ion/electron transfer dynamics and high electroactivity. In comparison to the LTH obtained from the electrodeposition method (without the ZIF-67 precursor) and that derived from leaf-like ZIF-Co, this modified microfiber exhibited a high charge storage capacity of 1.5 mA h cm-2 (149.9 mA h cm-3 and 0.187 mA h cm-1) at 4 mA cm-2 and possesses an excellent durability of 98.4% after 5000 cycles. Additionally, FeCoS nanoflakes were electrodeposited using carbon fiber coated with an rGO-nanocellulose hydrogel (GNCH) and employed as a negative 1D microelectrode, which delivered a high specific capacitance of 1223 mF cm-2 (83 F cm-3, 232.4 mF cm-1) at 4 mA cm-2 with a superior cyclic lifespan. Ultimately, the assembled 1D flexible micro-device (Ni2Mo3N-CoN/Ni,S-doped Cu@CW//FeCoS/GNCH@CF) yielded an energy density of 7.2 mW h cm-3 at a power density of 294 mW cm-3 and outstanding cycling stability in PVA/KOH electrolyte and preserved the capacitive performance under various bending states. This research highlights that assembled 1D micro-SCs have a high potency for next-generation portable/wearable energy-supply microelectronics.

Thymol: nature's solvent for sustainable hollow fiber fabrication

Sustainable separation processes like membrane technology are crucial for chemical and pharmaceutical industries. Membrane fabrication needs green materials.

Applicability of Phosponated Poly(pentafluorostyrene) Fiber Reinforced Nafion Composite Membranes in Low-Temperature Fuel Cells

Reducing the fuel crossover of proton exchange membranes (PEMs) is an important measure to improve the fuel efficiency and performance of fuel cells and electrolyzers 1, 2. Additionally, the long-term stability and safety of PEM-based systems increase with a reduction in the gas crossover 1, 3, 4. A possible approach for reducing the gas crossover of a PEM is the implementation of fiber meshes to form a composite membrane 5. Furthermore, fiber-reinforced composite membranes can also increase the mechanical properties of PEMs and therefore enable the utilization of thinner membranes without sacrificing the mechanical integrity of the membrane or causing safety risks 6.In this work, we demonstrate the successful fabrication of electrospun fibers of a partially phosophonated, conductive polymer (phosponated poly(pentafluorostyrene); PWN70) and its non-phosphonated and, therefore, non-conductive equivalent (poly(pentafluorostyrene); PPFSt). Two different loadings of both fiber meshes were successfully infiltrated with Nafion, analyzed mechanically and electrochemically, and compared to a non-reinforced Nafion reference. We show that the mechanical properties of both fiber-reinforced composite membranes are superior to the reference membrane. The electrochemical analysis of the membrane electrode assemblies (MEAs) shows a reduction in performance with the incorporation of the non-conductive PPFSt fibers. An increase in the high-frequency resistance (HFR) of the MEAs containing the non-conductive PPFSt fibers explains the reduced performance and scales with fiber loading. In contrast, the MEAs with the proton conductive PWN70 fiber reinforcement maintained the same HFR and performance as the reference, independently of the fiber loading. Additionally, hydrogen crossover measurements revealed a significantly reduced hydrogen crossover of the MEAs composed of the conductive PWN70 fiber-reinforced membranes (between 30 and 40 % less than the reference). We hypothesize that PWN70 shows a decreased diffusivity for hydrogen compared to Nafion, and therefore, the fibers in the Nafion matrix increase the tortuosity of the membrane for fuel crossover.In summary, we developed a fiber-reinforced Nafion membrane with improved mechanical and gas barrier properties while maintaining the membrane's proton conductivity compared to the same membrane without reinforcement.References Q. Tang, B. Li, D. Yang, P. Ming, C. Zhang and Y. Wang, Int. J. Hydrog. Energy, 46(42), 22040–22061 (2021).M. Schalenbach, M. Carmo, D. L. Fritz, J. Mergel and D. Stolten, Int. J. Hydrog. Energy, 38(35), 14921–14933 (2013).B. Wu, M. Zhao, W. Shi, W. Liu, J. Liu, D. Xing, Y. Yao, Z. Hou, P. Ming, J. Gu and Z. Zou, Int. J. Hydrog. Energy, 39(26), 14381–14390 (2014).C. Klose, P. Trinke, T. Böhm, B. Bensmann, S. Vierrath, R. Hanke-Rauschenbach and S. Thiele, J. Electrochem. Soc., 165(16), F1271-F1277 (2018).J. Choi, K. M. Lee, R. Wycisk, P. N. Pintauro and P. T. Mather, Macromolecules, 41(13), 4569–4572 (2008).J. B. Ballengee and P. N. Pintauro, Macromolecules, 44(18), 7307–7314 (2011).

Fabrication and tribological properties of carbon fiber and copper fiber reinforced carbon-based composite by hot pressing

To attain new pantograph skateboard with high strength-toughness and simple fabrication process, copper fiber and carbon fiber reinforced carbon-based composite (Cuf/Cf/C composite) was fabricated by hot pressing technology, micro-structure, mechanical and tribological performances were investigated and compared with the results of carbon skateboard. Cuf/Cf/C composite is superior to carbon skateboard in terms of compactness, hardness, electrical conductivity, mechanical strength and wear resistance. During sliding friction tests with electric current, mechanical acting wear and arc erosion have a stimulating circulation on the worn surface, and adding carbon fiber slows down the deteriorated wear cycle and improves wear resistance. High carbon crystallinity degree of the tribolayer presents low molecular acting friction force, and adjusting crystallite structure is essential to improve friction performance.

Fabrication of high performance polyimide fibers by dry-jet wet spinning technology

High-performance co-polyimide (co-PI) fibers derived from 3,3`4,4`-biphenyldianhydride (BPDA), p-phenylenediamine (p-PDA) and 2-(4-aminophenyl)-5-amino-benzimidazole (BIA) were prepared via the wet spinning and dry-jet wet spinning method, respectively. The distinctions between wet spinning and dry-jet wet spinning processes on the structures and properties of co-PI fibers were systematically investigated. The co-PI fibers prepared by dry-jet wet spinning exhibited smoother surface morphology and higher mechanical properties than those of co-PI prepared by wet spinning. Wide-angle X-ray diffraction (WAXD) results showed that the co-PI fibers prepared by dry-jet wet spinning exhibited highly oriented structure along the fiber direction along with a low degree of lateral packing order in the transverse direction. Small-angle X-ray scattering (SAXS) revealed that the radius, length, misorientation and internal surface roughness of the microvoids in the co-PI fibers prepared by the dry-jet wet spinning are lower than those in co-PI fibers prepared by wet spinning. Moreover, the effect of air layer height, as well as the heat treatment on the structure and properties of fibers during the dry-jet wet spinning process, was also studied. The tensile strength and modulus of co-PI fibers prepared by dry-jet wet spinning reached 2.72 GPa and 114.29 GPa, respectively, with an air layer height of 10 mm and a heat stretching temperature of 440°C.

Nanoscopic decoration of multivalent vanadium oxide on Laser-Induced graphene fibers via atomic layer deposition for flexible gel supercapacitors

Composite materials for high energy/power density supercapacitors are of very high importance. The precise well-defined nanoarchitectonics approach is a key element in the construction of high-performance devices. Surface redox reactions that frequently involve the exchange of oxygen atoms are fundamental to pseudocapacitive reactions mostly mediated by transition metal oxides (TMO). This process often changes the surface stoichiometry and atomic rearrangement in case of uncontrolled growth of TMO. Atomic layer deposition (ALD) has proven to be a facile process for smooth and uniform decoration of TMO on the electrochemically active carbon material to form a binder-free flexible composite material for supercapacitor (SC) applications. Although active carbon materials can be fabricated using various printing and lithographic techniques, continued improvement of cost and scalability, and low dimensional matrix are required to realize their full potential. Here, we demonstrate the scalable fabrication of laser-induced graphene fibers (LIGF) followed by ALD of multivalent vanadium oxide (VOx) films on the LIGF network (VOx-LIGF). The resultant VOx-LIGF shows a specific areal capacitance as high as 99 mF cm−2 at 1 mA cm−2 (aqueous solution, three-electrode cell) and 2 mF cm−2 at 0.25 mA cm−2 (gel electrolyte, two electrode cell). Moreover, the miniaturized supercapacitor device delivers a power density of 244 mW cm−3 as well as long-term cycling stability (93 % capacitance retention after 11,500 cycles) which is among the highest values achieved for any SC. Despite mechanical stress, these flexible supercapacitors maintain excellent electrochemical aspects and thus hold promise for high-power flexible and wearable electronics. Such a general, precise, well-defined, and low-cost route for atomic layer deposition-laser pulse-enhanced supercapacitor materials should find widespread applications.