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The long-range aim of this research is to develop porous ceramics with high strength, excellent thermal resistance and chemical stability at high temperature in environmental industry. The C_f/SiC was made by hot pressing method with SiC powder whose particle size is 50nm and less on the average also Al₂O₃, Y₂O₃ and SiO₂ as additive. The carbon fibers of oxidation property are investigated by TGA for finding out decarburization point. As a result, decarburization point selected the specific temperature of TGA curve and the C_f/SiC composites occurred perfectly decarburization at carbon fibers so the clearly porous SiC ceramics were formed many holes of 3-5µm diameters through length direction by its reaction.

In this research, hull structure of Ray-type Underwater Glider (RUG) that could be a next generation unmanned vehicle was studied. RUG is capable of long-term operation at higher speeds than conventional cylindrical underwater gliders due to its ray shaped body composed of dual buoyancy engine. For long-term operation, it is necessary to develop a lightweight control housing and battery case. For this reason, the carbon fiber container was used to be lighter and stronger than duralumin used in the past. Through the stress and buckling analysis, it was shown that the container was able to withstand the pressure of 200 m which is the target water depth with the safety ratio of about 1.8 times. Using a carbon composite material, the mechanical strength can be maintained while reducing the weight of the pressure vessel by more than 40% compared with the high tensile aluminum material.

The purpose of this study is to determine the correct estimation of laminate patterns for high-strength composites applied to a ship. Recently, the need for developing a ship component has been increasing to improve the capability of maritime operations. Composites with excellent specific strength and specific stiffness are emerging as next-generation materials. In the composite material, the mechanical properties vary depending on the laminated pattern of the reinforcing material. Therefore, in this study, the properties of the composite materials were calculated using the computer simulation program. The ply calibration performance results show that the initial values of the mechanical properties of the carbon/epoxy composites in the E11 direction are higher than the calculated values, and the remaining values are the same. The laminate mechanics results show that the tensile strength in the S11T direction was 1515 MPa, which is almost the same as the initial value of 1500 MPa.

In this paper, a newly designed composite of magnetic nano-Co₃O₄ fiber coated on carbon fiber (Cf) is prepared and characterized for the electromagnetic interference (EMI) shielding properties. XRD, SEM and TEM are used to investigate the micromorphology and microstructure evolution during the preparation. By hydrothermal method, the flowerlike clusters of single crystal flake-Co(OH)₂ are first obtained on Cf. The firstly prepared Co(OH)₂ sheets then turn into Co₃O₄ fibers during the next calcination step. The continuous and loose coating of magnetic Co₃O₄ nanofibers is finally obtained on the Cf. The loose coating is in proportion to the weight loss, and the wirelike Co₃O₄ is good for the interface strength for the Cf composite preparation. Based on the above work, the loose magnetic fibers coating on the Cf could be a feasible composite structure for the EMI composite materials integrated with absorbing and reflecting.

The aim of this study is to discuss the effect of moisture absorption on electrical conductivity and electromagnetic interference of the carbon fiber (CF) reinforced bioplastic composite. The composites were prepared by the hot press machine, and immersed in water for 20 and 40 days. The electrical conductivity measurements were carried out as a function immersed time. The electrical conductivity of CF with two layers is greater than that of one layer, because the electrical conductivity increases with increasing the volume filler of CF. The electrical conductivity slightly increases with increasing the immersion time. The EMI SE (electromagnetic interference shielding effectiveness) of the composite was examined with the frequency from 500 MHz to 2000 MHz. The EMI SE of the CF increases with increasing the content of the CF, and the EMI SE result of composite is around 50 dB to 60 dB. There is scarcely significant effect of orientation on composite on the EMI SE.

Friction and wear processes of AgCuX (G, CF and AlN) composites-CuAgV alloy friction pair and effects of different additive content in silver based composite on friction and wear behavior are studied in this paper. The microstructure of the brush wear surface is observed by SEM. The results show that when graphite content is up to 9 wt.%, Ag-Cu-CF-G composite exhibits the best wear properties; when the content of aluminum nitride is up to 0.5 wt.%, Ag-Cu-AlN-G composites has the most comprehensive performance. The wear loss of both composites arises with the increase of both pressure and speed, but when speed reaches a critical value, the increased amplitude of wear loss tends to be steady.

Amperometric glucose sensors with a diameter of less than 10 μm were fabricated by the immobilization of glucose oxidase (GOx) on carbon fiber electrodes. Carbon fiber electrodes with platinum thin film were also prepared using electroplating and sputtering. The combination of electrodeposition and electropolymerization was employed for the immobilization of GOx. Although the introduction of Pt film satisfactorily improved the oxidation current of the electrode to hydrogen peroxide, sensitivities of obtained GOx-immobilized electrodes to glucose were not significant. Formation of electroplated-platinum thin film on carbon fiber was effective to reduce the influence of electroactive compounds existing in biological fluid such as ascorbic and uric acids.

In this study, two kinds of bioplastic materials, where the first consists of 10% PLA, corn starch of 80% and CaCO₃ 10%, and the second consists of 45% PLA content, corn starch of 45% and CaCO₃ 10%, were used. The composites were also reinforced by the carbon fibers, which were prepared with one and two layers of carbon fiber and then ply orientations of [0${}^{\circ }$] and [45${}^{\circ }$]. The maximum tensile strength was observed for PLA 45% with a [0${}^{\circ }$] ply orientation of two layers of carbon fiber. For composite with two layers of carbon fiber, the tensile strength showed higher for the [0${}^{\circ }$] ply orientation than for the [45${}^{\circ }$] ply orientation. The fatigue strength strongly depends on the orientation of carbon fiber, but in the long fatigue life range, the difference of fatigue strength between the fiber ply orientations reduces.

Novel Fe–Ni alloy coated carbon fibers (Fe–Ni–CFs) were prepared via two-step electrodeposition with an initial synthesis of Fe coatings on the activated carbon fibers and followed by the co-deposition of Fe and Ni. The effect of annealing treatment on structure and properties of Fe–Ni–CFs was studied through SEM, TEM, XRD and VSM. The results indicated that the Fe–Ni alloy coatings with the thickness of only 0.25 um are highly wrapped on the surface of carbon fibers. The un-annealed coatings showed high saturation magnetization values with 52 dB from 300–1200 MHz, which mainly due to Fe content (18.4 wt.%) of the coatings meets the requirements of high magnetic perm-alloy. The surface quality, crystallinity and conductivity of the Fe–Ni–CFs were obviously improved despite of the reduction of the saturation magnetization resulted from the bigger grains after annealing. Based on the above aspects, annealing at 400^∘C was preferred for the Fe–Ni–CFs to obtain good comprehensive performance. Importantly, the Fe–Ni–CFs filled ABS resin composites showed better Electromagnetic Interference shielding effectiveness than the CFs reinforced ABS composites.

This paper describes a theoretical approach to compare two types of fiber reinforced composite materials for femoral component of hip implants. The natural fiber reinforced composite implant is compared with carbon fiber reinforced composite and the results are evaluated against the control solution of a metallic implant made of titanium alloy. With identical geometry and loading condition, the composite implants assumed lower stresses, thus induced more loads to the bone and consequently reduced the risk of stress shielding, whilst the natural fiber reinforced composite showed promising result compared with carbon fibers. However, natural fibers, as well as carbon fibers, lack the power to improve interface debonding due to excessive loads in interface. Nevertheless, natural fiber reinforced composite could be an appropriate alternative given its capability of tailoring and achieving the optimal fiber orientation and robust design.

A newly designed gas phase thermal decomposition reactor, ohmically heating the catalytic sites, has been used to synthesize multiwall carbon nanotubes (MWCNTs) on carbon paper and stainless steel screen. Co-Ni catalyst particles were dispersed by a silane intermediate layer adsorbed onto the carbon fibers or the stainless steel threads of the supports. MWCNTs were obtained on both substrates by a tip grown mechanism. They are about 20 μm in length and 15–50 nm in diameter. A methanol pretreatment of the carbon fibers significantly increased the density of the tubes on the carbon paper, but the same treatment had a negative effect on stainless steel. The MWCNTs, which adhere firmly to the carbon paper and the stainless steel screen, may find applications as electrodes in fuel cells, sensors and in photonics.

We investigated the compressive strength of PAN-based carbon fibers containing both amorphous and crystalline structures using molecular dynamics simulations. In addition, we investigated the buckling behavior of graphene and graphite crystals under compressive loading. The calculated buckling stresses of those crystals with different aspect ratios agree well with the results by the Euler's buckling theory. We finally found that the compressive strength of the PAN-based carbon fiber with a large amount of amorphous structures was 11 GPa. Moreover, a fracture of the PAN-based carbon fiber begins due to the buckling of carbon layers in crystallites, and propagates with the shear slipping in the crystallites. On the other hand, the compressive strength of the carbon fiber with a small amount of amorphous structures was only 2 GPa. Thus, it was found that the amorphous structure significantly affects the compressive strength of PAN-based carbon fibers.

The vibrational behavior of polymer matrix nanocomposite plates reinforced with carbon fibers (CFs) and carbon nanotubes (CNTs) is studied using the finite element method based on a multi-scale modeling approach. The influences of nano- and micro-scale are coupled through a two-step procedure. First, CNTs are dispersed into the polymer matrix. In the selected representative volume element (RVE), interphase due to chemical interaction between CNT and polymer matrix is considered. Also, the state of dispersion of CNTs into the matrix is assumed to be random. In the second step, CFs are randomly distributed in the reinforced polymer with CNTs. The reinforcement is carried out for various volume fractions of CFs and CNTs. Two three-dimensional models including the brick and shell ones are used to generate the results. Moreover, the analysis is presented for square plates under different types of boundary conditions. The effect of nanocomposite thickness on its vibrational response is also investigated.

The purpose of the present paper is to study the effect of hybridation, stacking sequences and fiber orientation on the damping properties of unidirectional carbon/flax fiber reinforced epoxy composites. Non-hybrid and hybrid laminates with different stacking sequences were produced by molding vacuum process. Free vibration tests with an impulse technique were performed on test specimens to investigate the dynamic behavior. Finite element analysis was used to model damping to evaluate the different energies dissipated in the material layer directions of the carbon/flax composites. Close agreement was found between the experimentally measured values and those derived from the numerical simulation for the damping coefficients. The results obtained show that flax layers had a significant effect on damping properties.

The passive direct methanol fuel cell (DMFC) is a promising candidate power source for portable applications but has to deal with many technical challenges before practical use. This study presents a preliminary investigation on the use of a woven carbon fiber fabric (WCFF) for constructing a gradient porous structure based on the traditional design. The WCFF, carbon paper and carbon-black micro porous layer (MPL) combine into a carbon-based assembly which acts as a mass-transfer-controlling medium at the anode of a passive DMFC. Results show that this novel setup is able to significantly improve the cell performance and facilitate high-concentration operation. A maximum power density of 16.4 mWcm^-2 is obtained when two layers of the WCFF are used at a methanol concentration of 8M. This work provides an effective method for using concentrated methanol with no need for major change of the fuel cell configuration.

We report a novel preparing route to SiO₂ nanowires, which can be regarded as a modified electrochemical process, where a single C fiber is used as a substrate on which SiO₂ nanowires grow, and a heating source, and tetraethyl orthosilicate (TEOS) as an electrolyte and cooling medium. The preparing process can proceed well at ambient temperature and pressure. A good quality of SiO₂ nanowires can be easily obtained at 160V for only 10s, and exhibit excellent photoluminescence (PL) property. Our study also shows that reaction time, current intensity, and TEOS concentration mainly govern the formation and growth of SiO₂ nanowires. The morphology, structure and composition of the as-synthesized samples were characterized by SEM, XPS, Raman, FTIR, and PL, respectively.

Fiber-shaped supercapacitor has drawn more attention for wearable electronic devices. We prepared hierarchical porous carbon fiber (HPCF) successively by phase-separable wet-spinning of polyacrylonitrile, preoxidation and carbonization with tension to use for the fiber-shaped electrode. The added tension during preoxidation and carbonization and the elevated temperature of carbonization improve the order carbon structure and the graphitization degree, endowed HPCF with high strength of 326.95 MPa. Thus, the all solid-state fiber-shaped supercapacitor is assembled without breakage. In addition, the hierarchical porous structure of HPCF with specific surface area of 276.0 m² g${}^{-1}$ contributes a high specific capacitance of 158 F g${}^{-1}$. The novel porous carbon fiber in this work exhibits the appropriate potential for wearable applications.

To deal with environmental issues, the gasoline mileage of passenger cars can be improved by reduction of the car weight. The use of car components made of Carbon Fiber Reinforced Plastics (CFRP) is increasing because of its superior mechanical properties and relatively low density. Many vehicle structural parts are pipe-shaped, such as suspension arms, torsion beams, door guard bars and impact beams. A reduction of the car weight is expected by using CFRP for these parts. Especially, when considering the recyclability and ease of production, Carbon Fiber Reinforced Thermoplastics are a prime candidate. On the other hand, the moulding process of CFRTP pipes for mass production has not been well established yet. For this pipe moulding process an induction heating method has been investigated already, however, this method requires a complicated coil system. To reduce the production cost, another system without such complicated equipment is to be developed. In this study, the pipe moulding process of CFRTP using direct resistance heating was developed. This heating method heats up the mould by Joule heating using skin effect of high-frequency current. The direct resistance heating method is desirable from a cost perspective, because this method can heat the mould directly without using any coils. Formerly developed Non-woven Stitched Multi-axial Cloth (NSMC) was used as semi-product material. NSMC is very suitable for the lamination process due to the fact that non-crimp stitched carbon fiber of [0°/+45°/90°/-45°] and polyamide 6 non-woven fabric are stitched to one sheet, resulting in a short production cycle time. The use of the pipe moulding process with the direct resistance heating method in combination with the NSMC, has resulted in the successful moulding of a CFRTP pipe of 300 mm in length, 40 mm in diameter and 2 mm in thickness.

Sensing is a basic ability of smart structures. Self-sensing involves the structural material sensing itself. No device incorporation is needed, thus resulting in cost reduction, durability enhancement, sensing volume increase and absence of mechanical property diminution. Carbon fiber renders electrical conductivity to a composite material. The effect of strain/damage on the electrical conductivity enables self-sensing. This review addresses self-sensing in structural composite materials that contain carbon fiber reinforcement. The composites include polymer-matrix composites with continuous carbon fiber reinforcement (relevant to aircraft and other lightweight structures) and cement–matrix composites with short carbon fiber reinforcement (relevant to the civil infrastructure). The sensing mechanisms differ for these two types of composite materials, due to the difference in structures, which affects the electrical and electromechanical behaviors. For the polymer–matrix composites with continuous carbon fiber reinforcement, the longitudinal resistivity in the fiber direction decreases upon uniaxial tension, due to the fiber residual compressive stress reduction, while the through-thickness resistivity increases, due to the fiber waviness reduction; upon flexure, the tension surface resistance increases, because of the reduction in the current penetration from the surface, while the compression surface resistance decreases. These strain effects are reversible. The through-thickness resistance, oblique resistance and interlaminar interfacial resistivity increase irreversibly upon fiber fracture, delamination or subtle irreversible change in the microstructure. For the cement–matrix composites with short carbon fiber reinforcement, the resistivity increases upon tension, due to the fiber–matrix interface weakening, and decreases upon compression; upon flexure, the tension surface resistance increases, while the compression surface resistance decreases. Strain and damage cause reversible and irreversible resistance changes, respectively. The incorporation of carbon nanofiber or nanotube to these composites adds to the costs, while the sensing performance is improved marginally, if any. The self-sensing involves resistance or capacitance measurement. Strain and damage cause reversible and irreversible capacitance changes, respectively. The fringing electric field that bows out of the coplanar electrodes serves as a probe, with the capacitance decreased when the fringing field encounters an imperfection. For the cement-based materials, a conductive admixture is not required for capacitance-based self-sensing.

There are mines of elemental carbon such as graphite. It is the most stable form of elemental carbon at 25°C, under 1 atm (Section 3.7). A second form of pure or nearly pure elemental carbon is represented by diamonds (Section 3.12). Other forms of elemental carbon are produced by combustion or heat treatment of wood (Section 3.6), bio-polymers such as paper, cotton (cellulose), or synthetic polymers such as viscose (Section 11.10.1) and polyacrylonitrile (Section 8.2.7). Nanoparticles such as graphene (Section 3.7), fullerenes (Section 3.8), nanotubes (Section 3.9), and quantum dots of carbon (Section 3.10) are available that find biomedical applications and are used in the manufacture of nanometric objects useful for electronics, optoelectronics, photophysics, energy and the environment protection. Nanoparticles must be handled with care as they can be toxic…