Showing papers on "Fiber published in 2016"
TL;DR: The technique enables direct 3D fabrication without the use of molds and may become the standard next-generation composite fabrication methodology.
Abstract: We have developed a method for the three-dimensional (3D) printing of continuous fiber-reinforced thermoplastics based on fused-deposition modeling. The technique enables direct 3D fabrication without the use of molds and may become the standard next-generation composite fabrication methodology. A thermoplastic filament and continuous fibers were separately supplied to the 3D printer and the fibers were impregnated with the filament within the heated nozzle of the printer immediately before printing. Polylactic acid was used as the matrix while carbon fibers, or twisted yarns of natural jute fibers, were used as the reinforcements. The thermoplastics reinforced with unidirectional jute fibers were examples of plant-sourced composites; those reinforced with unidirectional carbon fiber showed mechanical properties superior to those of both the jute-reinforced and unreinforced thermoplastics. Continuous fiber reinforcement improved the tensile strength of the printed composites relative to the values shown by conventional 3D-printed polymer-based composites.
722 citations
TL;DR: In this article, a 3D printing based fabrication process of continuous fiber reinforced thermoplastic composites (CFRTPCs) was proposed, where continuous carbon fiber and PLA filament were utilized as reinforcing phase and matrix, respectively, and simultaneously fed into the fused deposition modeling (FDM)3D printing process.
Abstract: A novel 3D printing based fabrication process of Continuous Fiber Reinforced Thermoplastic Composites (CFRTPCs) was proposed. Continuous carbon fiber and PLA filament were utilized as reinforcing phase and matrix, respectively, and simultaneously fed into the fused deposition modeling (FDM) 3D printing process realizing the integrated preparation and forming of CFRTPCs. Interfaces and performance of printed composites were systematically studied by analyzing the influencing of process parameters on the temperature and pressure in the process. Forming mechanism of multiple interfaces was proposed and utilized to explain the correlations between process and performance. Fiber content of the printed specimens can be easily controlled by changing the process parameters. When the fiber content reached 27%, flexural strength of 335 MPa and modulus of 30 GPa were obtained for the printed composite specimens. Composite components were fabricated to demonstrate the process feasibility. Potential applications could be found in the field of aviation and aerospace.
707 citations
TL;DR: A hollow graphene/conducting polymer composite fiber is created with high mechanical and electronic properties and used to fabricate novel fiber-shaped supercapacitors that display high energy densities and long life stability.
Abstract: A hollow graphene/conducting polymer composite fiber is created with high mechanical and electronic properties and used to fabricate novel fiber-shaped supercapacitors that display high energy densities and long life stability. The fiber supercapacitors can be woven into flexible powering textiles that are particularly promising for portable and wearable electronic devices.
620 citations
TL;DR: Fiber-reinforced polymer composites (FRPCs) made of a "dynamic" epoxy resin possess good mechanical properties, while showing reprocessability, reparability and recyclability.
Abstract: Fiber-reinforced polymer composites (FRPCs) made of a “dynamic” epoxy resin possess good mechanical properties, while showing reprocessability, reparability and recyclability. The FRPCs are easily synthesized from readily available materials and could therefore be easily implemented in transportation, energy or construction industries, among others.
526 citations
TL;DR: In this paper, the authors evaluate the elastic properties of the fiber reinforced 3D printed structures and predict elastic properties using an Average Stiffness (VAS) method using the MarkOne by Mark Forged 3D printer.
416 citations
TL;DR: A comprehensive review of the carbon fiber production process, from polymerization to fiber spinning and stabilization and carbonization, is provided in this paper, where relationships between carbon fiber microstructure and material performance is undertaken in order to assess the current status of the mechanical, thermal, and electrical properties of commercially available PAN and pitch based carbon fibers, as well as recently developed experimental carbon fibers.
Abstract: Carbon fiber is increasingly being utilized as a reinforcing material due to its high strength and high modulus, which is imparted into the properties of the final composite. A comprehensive review of the carbon fiber production process, from polymerization to fiber spinning and stabilization and carbonization, is provided. Relationships between carbon fiber microstructure and material performance is undertaken in order to assess the current status of the mechanical, thermal, and electrical properties of commercially available PAN and pitch based carbon fibers, as well as recently developed experimental carbon fibers. A discussion of next generation carbon fibers is also provided, with a discussion on carbon fiber derived from alternative precursor materials, as well as hierarchical carbon fiber composites.
362 citations
TL;DR: A core-clad fiber made of elastic, tough hydrogels is highly stretchable while guiding light and when stretched, the transmission spectrum of the fiber is altered, enabling the strain to be measured and also its location.
Abstract: A core-clad fiber made of elastic, tough hydrogels is highly stretchable while guiding light. Fluorescent dyes are easily doped into the hydrogel fiber by diffusion. When stretched, the transmission spectrum of the fiber is altered, enabling the strain to be measured and also its location.
317 citations
TL;DR: In this article, the authors present a new paradigm to fully recycle epoxy-based carbon fiber reinforced polymer (CFRP) composites, where the epoxy matrix can be dissolved as the EG molecules participate in bond exchange reactions (BERs) within the covalent adaptable network (CAN), effectively breaking the long polymer chains into small segments.
Abstract: Both environmental and economic factors have driven the development of recycling routes for the increasing amount of composite waste generated. This paper presents a new paradigm to fully recycle epoxy-based carbon fiber reinforced polymer (CFRP) composites. After immersing the composite in ethylene glycol (EG) and increasing the temperature, the epoxy matrix can be dissolved as the EG molecules participate in bond exchange reactions (BERs) within the covalent adaptable network (CAN), effectively breaking the long polymer chains into small segments. The clean carbon fibers can be then reclaimed with the same dimensions and mechanical properties as those of fresh ones. Both the dissolution rate and the minimum amount of EG required to fully dissolve the CAN are experimentally determined. Further heating the dissolved solution leads to repolymerization of the epoxy matrix, so a new generation of composite can be fabricated by using the recycled fiber and epoxy; in this way a closed-loop near 100% recycling paradigm is realized. In addition, epoxy composites with surface damage are shown to be fully repaired. Both the recycled and the repaired composites exhibit the same level of mechanical properties as fresh materials.
310 citations
TL;DR: It is found that the oriented fibers greatly enhance and facilitate the metastatic cell intravasation process during metastasis, and it is suggested that a possible “tissue treatment” therapy could be considered, in which the ECM fiber structure orientation in the tumor microenvironment might be altered to minimize the intravAsation rate of metastatic cells.
Abstract: In this work, we constructed a Collagen I-Matrigel composite extracellular matrix (ECM). The composite ECM was used to determine the influence of the local collagen fiber orientation on the collective intravasation ability of tumor cells. We found that the local fiber alignment enhanced cell-ECM interactions. Specifically, metastatic MDA-MB-231 breast cancer cells followed the local fiber alignment direction during the intravasation into rigid Matrigel (∼10 mg/mL protein concentration).
271 citations
TL;DR: In this article, the effects of mild alkali treatments on the mechanical characteristics and interfacial adhesion of the fibers in a model abaca fiber/epoxy composite system was systematically evaluated.
Abstract: Abaca fibers demonstrate enormous potential as reinforcing agents in composite materials. In this study, abaca fibers were immersed in 5, 10 or 15 wt.% NaOH solutions for 2 h, and the effects of the alkali treatments on the mechanical characteristics and interfacial adhesion of the fibers in a model abaca fiber/epoxy composite system systematically evaluated. After 5 wt.% NaOH treatment, abaca fibers showed increased crystallinity, tensile strength and Young’s modulus compared to untreated fibers, and also improved interfacial shear strength with an epoxy. Stronger alkali treatments negatively impacted fiber stiffness and suitability for composite applications. Results suggest that mild alkali treatments (e.g. 5 wt.% NaOH for 2 h) are highly beneficial for the manufacture of abaca fiber-reinforced polymer composites.
258 citations
TL;DR: In this article, a bibliographic review is presented to demonstrate the tribological behavior of natural fiber reinforced composites and find a knowledge about their usability for various applications that tribology plays a dominant role.
TL;DR: The prepared nano-dimensional cellulose demonstrated a network-like structure with higher crystallinity than that of untreated fiber, and possessed of good thermal stability which is suitable for nanocomposite material.
TL;DR: In this article, a simple and effective double-side pullout testing method was adopted to characterize the interfacial bond properties, which include pullout load-slip relationship, bond strength, and pullout energy, of steel fiber-matrix in ultra-high strength cement-based material (UHSC) with 0-25% silica fume by the mass of binder.
Abstract: The use of silica fume can significantly enhance mechanical properties of concrete given its beneficial filling and pozzolanic effects. In this study, a simple and effective double-side pullout testing method was adopted to characterize the interfacial bond properties, which include pullout load-slip relationship, bond strength, and pullout energy, of steel fiber-matrix in ultra-high strength cement-based material (UHSC) with 0–25% silica fume by the mass of binder. The effects of silica fume content on flowability, heat of hydration, compressive and flexural strengths, hydration products, and pore structure of matrix at different curing time were evaluated as well. Backscatter scanning electron microscopy (BSEM) and micro-hardness measurement were used to examine the quality of interfacial transition zone (ITZ) around the fiber. In terms of the results, the optimal silica fume content could be in the range of 15%–25%. UHSC mixtures with these dosages of silica fume showed significant improvement in pullout behavior. Its bond strength and pullout energy at 28 d could increase by 170% and 250% compared to the reference samples without any silica fume. The microstructural observation verified the findings on the macro-properties development. Formation of more and higher strength of hydration products and refinement of ITZ around the fiber ensured higher micro-hardness, and thus improved the bond to fiber.
TL;DR: In this paper, a systematic experimental investigation is carried out on concrete with rubber fibers (obtained by grinding waste rubber tyres) as partial replacement of fine aggregates, to evaluate the compressive strength, density, water permeability, static modulus of elasticity, dynamic modulus, and chloride diffusion.
TL;DR: In this article, the authors discuss the much research that has been carried out in the area of the epoxy-based composites reinforced with natural fibers and the influence of various factors like the fiber content, fiber geometry, fiber size, surface treatment technique, and coupling agent on different properties like mechanical, thermal, behavior towards water absorption and others have been presented.
Abstract: With growing inclination towards the eco-friendly technology, natural fiber based polymer composite materials have been gaining a lot of momentum nowadays. The present review discusses the much research that has been carried out in the area of the epoxy-based composites reinforced with natural fibers. Influence of the various factors like the fiber content, fiber geometry, fiber size, surface treatment technique, and coupling agent on different properties like mechanical, thermal, behavior towards water absorption and others have been presented. It can be inferred that there is a need and scope for improvement of the surface properties of natural fiber using various methods like physical and chemical treatments, addition of coupling agents, etc. for the manufacturing of the composites having desired properties. These techniques not only modify surface morphology, but also improve other processing parameters like the hydrophilic character of fiber (which is desirable to be low), and hence improve several characteristics such as mechanical properties, thermal stability, water absorption and other considerations of the composites.
TL;DR: This study is expected to guide an effective way to recycle waste coal fly ash not only to solve its environmental problems but also to produce a high-valued mullite hollow fiber membrane for highly efficient separation application of O/W emulsion with potential simultaneous functions of pure water production and oil resource recovery.
TL;DR: In this paper, a hierarchical structured MnO 2 nanowire/graphene hybrid fibers are fabricated through a simple, scalable wet-spinning method, and the hybrid fibers form mesoporous structure with large specific surface area of 139.9m 2 ǫg −1.
TL;DR: In this paper, the effects of wettability, chemical characterization and nanometric roughness of two different fibers, polypropylene (PPF) and micro steel fibers (MSF), superposed by shrinkage of fly ash based geopolymer binder on fiber-matrix interaction and the consequent mechanical properties of the corresponding composites.
TL;DR: In this paper, the effect of adding different types of fibers on the microstructure and the mechanical behavior of cementitious composites, in particular on UHPC, was investigated by using a uni-axial compression test which combines the gas permeability and the acoustic emission (AE) measurement.
Abstract: This study investigates the effect of adding different types of fibers on the microstructure and the mechanical behavior of cementitious composites, in particular on UHPC. These fibers were distinguished mainly by their differing nature (steel, mineral and synthetic), their dimensions (macroscopic or microscopic), and their mechanical properties. The microstructure of the specimens was examined by using SEM observation and by measuring the porosity, the intrinsic permeability and the P-wave velocity. The mechanical behavior under loading has been studied using a uni-axial compression test which combines the gas permeability and the acoustic emission (AE) measurement. This work focuses on the cracking process under mechanical loading. The experimental results show that the fiber has a relatively slight influence on the compressive strength and elastic modulus of concrete, except for the steel fiber which improves the strength because of its intrinsic rigidity. However, The addition of fiber significantly reduces the lateral strain at peak loading and increases the threshold of initial cracking (σk-ci) and that of unstable cracking (σk-pi). Therefore, the fibers clearly restrain the cracking process in concrete under the mechanic loading.
TL;DR: In this article, the compatibility of polyurethane (PU) and graphene oxide (GO) is utilized for the study of the properties of elastomeric conductive fibers prepared by wet-spinning.
Abstract: Recent advances in wearable electronics, technical textiles, and wearable strain sensing devices have resulted in extensive research on stretchable electrically conductive fibers. Addressing these areas require the development of efficient fiber processing methodologies that do not compromise the mechanical properties of the polymer (typically an elastomer) when nanomaterials are added as conductive fillers. It is highly desirable that the addition of conductive fillers provides not only electrical conductivity, but that these fillers also enhance the stiffness, strength, stretchability, and toughness of the polymer. Here, the compatibility of polyurethane (PU) and graphene oxide (GO) is utilized for the study of the properties of elastomeric conductive fibers prepared by wet-spinning. The GO-reinforced PU fibers demonstrate outstanding mechanical properties with a 200-fold and a threefold enhancement in Young's modulus and toughness, respectively. Postspinning thermal annealing of the fibers results in electrically conductive fibers with a low percolation threshold (≈0.37 wt% GO). An investigation into optimized fiber's electromechanical behavior reveals linear strain sensing abilities up to 70%. Results presented here provide practical insights on how to simultaneously maintain or improve electrical, mechanical, and electromechanical properties in conductive elastomer fibers.
TL;DR: The sample with the optimal condition exhibited the highest specific capacitance, and with 10 000 charge-discharge cycles at 3 A g(-1), the supercapacitor kept 94.2% capacity, showing outstanding electrochemical performance as promising electrode material.
Abstract: Activated carbon fibers (ACFs) with different pore structure have been prepared from wood sawdust using the KOH activation method. A study was conducted to examine the influence of the activation parameters (temperature, alkali/carbon ratio, and time) on the morphology and structure of the as-prepared ACFs developed in the process of pore generation and evolution. Activation temperature was very essential for the formation of utramicropores (<0.6 nm), which greatly contributed to the electric double layer capacitance. The significance of metallic potassium vapor evolved when the temperature was above 800 °C, since the generation of 0.8- and 1.1 nm micropores cannot be ignored. When the the KOH/fiber ratio was increased and the activation time was prolonged, to some extent, the micropores were enlarged to small mesopores within 2–5 nm. The sample with the optimal condition exhibited the highest specific capacitance (225 F g–1 at a current density of 0.5 A g–1). Its ability to retain capacitance correspondi...
TL;DR: The engineered membranes exhibited stable MD performance with low surface tension feed waters, demonstrating the potential application omniphobic membranes in desalinating complex, high salinity industrial wastewaters.
Abstract: We investigated the factors that determine surface omniphobicity of microporous membranes and evaluated the potential application of these membranes in desalination of low surface tension wastewaters by membrane distillation (MD). Specifically, the effects of surface morphology and surface energy on membrane surface omniphobicity were systematically investigated by evaluating wetting resistance to low surface tension liquids. Single and multilevel re-entrant structures were achieved by using cylindrical glass fibers as a membrane substrate and grafting silica nanoparticles (SiNPs) on the fibers. Surface energy of the membrane was tuned by functionalizing the fiber substrate with fluoroalkylsilane (FAS) having two different lengths of fluoroalkyl chains. Results show that surface omniphobicity of the modified fibrous membrane increased with higher level of re-entrant structure and with lower surface energy. The secondary re-entrant structure achieved by SiNP coating on the cylindrical fibers was found to play a critical role in enhancing the surface omniphobicity. Membranes coated with SiNPs and chemically modified by the FAS with a longer fluoroalkyl chain (or lower surface energy) exhibited excellent surface omniphobicity and showed wetting resistance to low surface tension liquids such as ethanol (22.1 mN m(-1)). We further evaluated performance of the membranes in desalination of saline feed solutions with varying surface tensions by membrane distillation (MD). The engineered membranes exhibited stable MD performance with low surface tension feed waters, demonstrating the potential application omniphobic membranes in desalinating complex, high salinity industrial wastewaters.
TL;DR: Electrochemical tests in the solvent-in-salt-type Li-S battery electrolyte indicate that the Li-FeS2 system becomes a hybrid of theLi-S cell and Li-iron sulfide cell after the initial cycle.
Abstract: In this study, an FeS2@carbon fiber electrode is developed with FeS2 nanoparticles either embedded in or attached to carbon fibers by using an electrospinning method. By applying this binder-free, metal-current-collector-free FeS2@carbon fiber electrode, both the redox reaction and capacity decay mechanisms for the Li–FeS2 system are revealed by changing the electrolyte (conventional carbonate electrolyte and a “solvent-in-salt”-type Li–S battery electrolyte) and working voltage ranges (1.0–3.0 V and 1.5–3.0 V vs Li/Li+). The FeS2@carbon fiber electrode shows stable cycling performance in both the conventional carbonate electrolyte and the solvent-in-salt-type Li–S battery electrolyte in the voltage range of 1.5–3.0 V. Electrochemical tests in the solvent-in-salt-type Li–S battery electrolyte indicate that the Li–FeS2 system becomes a hybrid of the Li–S cell and Li–iron sulfide cell after the initial cycle. Based on the understanding on the capacity decay mechanisms, the cycling stability of the Li–FeS2 s...
TL;DR: In this article, a hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size, the particle sizes of 200nm and
TL;DR: Weavable fiber redox supercapacitors and strain sensors are here introduced, which comprise a dielectric layer sandwiched between functionalized buckled carbon nanotube electrodes that provide the dual functions of strain sensing and electrochemical energy storage.
Abstract: Twistable and stretchable fiber-based electrochemical devices having high performance are needed for future applications, including emerging wearable electronics. Weavable fiber redox supercapacitors and strain sensors are here introduced, which comprise a dielectric layer sandwiched between functionalized buckled carbon nanotube electrodes. On the macroscopic scale, the sandwiched core rubber of the fiber acts as a dielectric layer for capacitive strain sensing and as an elastomeric substrate that prevents electrical shorting and irreversible structural changes during severe mechanical deformations. On the microscopic scale, the buckled CNT electrodes effectively absorb tensile or shear stresses, providing an essentially constant electrical conductance. Consequently, the sandwich fibers provide the dual functions of (1) strain sensing, by generating approximately 115.7% and 26% capacitance changes during stretching (200%) and giant twist (1700 rad·m–1 or 270 turns·m–1), respectively, and (2) electrochemi...
TL;DR: In this paper, high-performance flexible textile electrodes and fiber electrodes are simultaneously produced by a newly proposed effective strategy, where Activated carbon fiber cloth (ACFC)/carbon nanotubes (CNTs) and ACFC/MnO2/CNT composites are designed as highperformance flexible fiber electrodes.
Abstract: High-performance flexible textile electrodes and fiber electrodes are produced simultaneously by a newly proposed effective strategy. Activated carbon fiber cloth (ACFC)/carbon nanotubes (CNTs) and ACFC/MnO2/CNTs composites are designed as high-performance flexible textile electrodes. Theses textiles can also be easily dismantled into individual fiber bundles used as high-performance flexible fiber electrodes.
TL;DR: The surface area of the formed phosphoric acid treated kenaf core fiber activated carbon (KFAC) was determined by physical adsorption of N 2 gas as discussed by the authors.
TL;DR: A carbon nanostructured hybrid fiber is developed by integrating mesoporous carbon and graphene oxide into aligned carbon nanotubes that is used as a 1D cathode to fabricate a new cable-shaped lithium-sulfur battery.
Abstract: A carbon nanostructured hybrid fiber is developed by integrating mesoporous carbon and graphene oxide into aligned carbon nanotubes. This hybrid fiber is used as a 1D cathode to fabricate a new cable-shaped lithium-sulfur battery. The fiber cathode exhibits a decent specific capacity and lifespan, which makes the cable-shaped lithium-sulfur battery rank far ahead of other fiber-shaped batteries.
TL;DR: The synthesis of PEO@PAN/PSU medium would not only make it a promising candidate for PM2.5 governance but also provide a versatile strategy to design and develop stable porous membranes for various applications.
Abstract: Airborne particle filtration proposed for fibers requires their assembly into porous structures with small pore size and low packing density. The ability to maintain structural stability upon deformation stress in service is essential to ensure a highly porous packing material that functions reliably; however, it has proven extremely challenging. Here, we report a strategy to create anti-deformed poly(ethylene oxide)@polyacrylonitrile/polysulfone (PEO@PAN/PSU) composite membranes with binary structures for effective air filtration by combining multijet electrospinning and physical bonding process. Our approach allows the ambigenous fiber framework including thin PAN nanofibers and fluffy PSU microfibers, through which run interpenetrating PEO bonding structures, to assemble into stable filtration medium with tunable pore size and packing density by facilely optimizing the bimodal fiber construction and benefiting from the PEO inspiration. With the integrated features of small pore size, high porosity, and...
TL;DR: In this article, the effects of replacing cement with silica fume in the reinforced self-compacting concrete with recycled steel fiber and study its mechanical properties and impact resistance were investigated.