Hybrid Carbon Fiber Research Articles

High-performance all-solid-state flexible supercapacitors based on manganese dioxide/carbon fibers

Flexible solid-state fiber supercapacitors are fabricated by directly electrodepositing ultrathin manganese dioxide (MnO2) nanosheets on commercial carbon fiber yarns. The deposition process is well controlled and the composition of MnO2 in fiber electrodes is optimized to enable fiber SCs to possess high specific capacitance. Conductive carbon fibers concurrently serve as current collectors in fiber SCs and as flexible substrates for the deposition of MnO2. A single MnO2/CFs fiber electrode exhibits a specific volumetric capacitance of 58.7 F cm−3 with a specific gravimetric capacitance of 428 F g−1 based on the MnO2 mass. Two hybrid carbon fiber electrodes are assembled together in parallel with polyvinyl pyrrolidone/Na2SO4 gel, which is used as both an electrolyte and a separator. The assembled flexible device exhibits a high volumetric energy density of 3.8 mW h cm−3 at a power density of 89 mW cm−3 with a good flexibility (CV curves almost unchanged after 2000 bending times) and a superior long cycle stability (an 85.8% capacitance retention after 10000 cycles). Moreover, the integrated SCs could power a commercial light-emitting-diode (LED), demonstrating its strong potential for the practical applications of flexible energy storage devices.

Modal testing of epoxy carbon–aramid fiber hybrid composites reinforced with silica nanoparticles

In the current paper, the modal characterisation of aramid–carbon fiber hybrid composites (ACFRP) and ACFRP reinforced with silica nanoparticles (nACFRP) is investigated through the analytical-experimental transfer function method. The modal properties, such as resonant frequencies and modal loss factors, are measured by vibrating cantilever beam specimens with an impact hammer, while the vibratory response is detected through an acceleration transducer. The procedure for the identification of analytical-experimental transfer functions is carried out using a genetic algorithm by minimising the difference between the measured response from tests and the calculated response, which is a function of the modal parameters. The analytical transfer functions provide a substructuring process to identify modes, as a function of damped natural frequencies and loss factors of a complex structure, and it is insensitive to experimental noise as well as the modal coupling effect. The validation of the proposed method is verified with 10 degrees of freedom mass-spring dashpot model. The effectiveness of the proposed method is demonstrated by investigating the static and dynamic behaviour of the ACFRP and nACFRP specimens. Results indicate that the inclusion of nanosilica particles increase the stiffness of the ACFRP, although the damping response of the reinforced specimens is moderately improved.

Biopolyamide hybrid composites for high performance applications

ABSTRACTThis study focuses on the performance characteristics of wood/short carbon fiber hybrid biopolyamide11 (PA11) composites. The composites were produced by melt‐compounding of the fibers with the polyamide via extrusion and injection molding. The results showed that mechanical properties, such as tensile and flexural strength and modulus of the wood fiber composites were significantly higher than the PA11 and hybridization with carbon fiber further enhanced the performance properties, as well as the thermal resistance of the composites. Compared to wood fiber composites (30% wood fiber), hybridization with carbon fiber (10% wood fiber and 20% carbon fiber) increased the tensile and flexural modulus by 168% and 142%, respectively. Izod impact strength of the hybrid composites exhibited a good improvement compared to wood fiber composites. Thermal properties and resistance to water absorption of the composites were improved by hybridization with carbon fiber. In overall, the study indicated that the developed hybrid composites are promising candidates for high performance applications, where high stiffness and thermal resistance are required. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43595.

Wild Fungus Derived Carbon Fibers and Hybrids as Anodes for Lithium-Ion Batteries

We reported a facile synthesis of carbonaceous fibers directly from Tyromyces fissilis wild fungus through a controlled carbonization process. Electron micrograph observations revealed that as-prepared carbon fibers are composed of 40–60 μm long solid and tubular fibers mimicking their natural texture. Raman spectroscopy and X-ray diffraction indicated that these carbon fibers are possessing disordered carbon structure with larger interlayer spacing (0.386 nm) than graphite (0.335 nm). These carbon fibers delivered specific reversible capacity of 340 mAh/g at C/10 rate and 300 mAh/g at C/5 rate. Electrochemical performance of as-prepared carbon fibers was further improved by uniform decoration of cobalt oxide particles via solid state thermal processing. CoO–carbon fiber hybrid anode delivered higher reversible capacity, 530 mAh/g at C/10 rate with only 10 mol % of CoO loading. This improvement is attributed to the synergistic effect, namely conductive network of cross-linked carbon fibers and facile elec...

Structural degradation and mechanical fracture of hybrid fabric reinforced composites

This investigation involves the study of accelerated environmental aging in two polymer composite laminates reinforced by hybrid fabrics based on carbon, Kevlar and glass fibers. Composite laminate configurations are defined as a laminate reinforced with E-glass fiber and Kevlar 49 fiber hybrid fabric (GK) and another laminate reinforced with E-glass fiber and AS4 carbon fiber hybrid fabric (GC). Both laminates were impregnated with epoxy vinyl ester thermosetting resin (Derakane 470-300) consisting of four layers. Morphological studies (photo-oxidation process and structural degradation) of environmental aging were conducted, in addition to comparative studies of the mechanical properties and fracture characteristics under the action of uniaxial tensile and three-point bending tests in specimens in the original and aged conditions. With respect to uniaxial tensile tests for both laminates, good mechanical performance and little final damage (small loss of properties) was caused by the aging effect. However, for the three-point bending tests, for both laminates, the influence of aging was slightly higher for all parameters studied. The low structural deterioration in the laminates is attributed to the high performance with the heat of the matrix (Derakane 470-300) and the characteristics of the hybrid fabric, exhibiting fiber/matrix interface quality. POLYM. ENG. SCI., 2016. © 2016 Society of Plastics Engineers

Enhancement in mechanical properties of multi-walled carbon nanotube–carbon fiber hybrid epoxy composite: effect of electrostatic repulsion

The effect of electrostatic repulsion of multi-walled carbon nanotube (MWCNT)–carbon fiber (CF) hybrid epoxy composites was studied on their mechanical properties. Electrophoretic deposition process was first used to deposit MWCNTs on CF surface. Subsequently, high-voltage direct electric field was applied to relocate deposited MWCNTs into radially aligned plates around the CF filaments. Scanning electron microscopy observations were implemented to study the surface characteristics of prepared hybrids. Moreover, fractography of MWCNT–CF hybrid epoxy composites has been performed to investigate the interfacial interactions in the CF/epoxy interphase. Assessment of the mechanical properties of electrostatic-applied MWCNT–CF hybrid composites unveiled significant improvements (157 % in tensile strength and 70 % in elastic modulus) in comparison with ordinary CF-reinforced composites.

Cutting Modeling of Hybrid CFRP/Ti Composite with Induced Damage Analysis.

In hybrid carbon fiber reinforced polymer (CFRP)/Ti machining, the bi-material interface is the weakest region vulnerable to severe damage formation when the tool cutting from one phase to another phase and vice versa. The interface delamination as well as the composite-phase damage is the most serious failure dominating the bi-material machining. In this paper, an original finite element (FE) model was developed to inspect the key mechanisms governing the induced damage formation when cutting this multi-phase material. The hybrid composite model was constructed by establishing three disparate physical constituents, i.e., the Ti phase, the interface, and the CFRP phase. Different constitutive laws and damage criteria were implemented to build up the entire cutting behavior of the bi-material system. The developed orthogonal cutting (OC) model aims to characterize the dynamic mechanisms of interface delamination formation and the affected interface zone (AIZ). Special focus was made on the quantitative analyses of the parametric effects on the interface delamination and composite-phase damage. The numerical results highlighted the pivotal role of AIZ in affecting the formation of interface delamination, and the significant impacts of feed rate and cutting speed on delamination extent and fiber/matrix failure.

Space-confined assembly of all-carbon hybrid fibers for capacitive energy storage: realizing a built-to-order concept for micro-supercapacitors

Customized hybrid carbon fiber supercapacitors with energy across two orders and power across four orders of magnitude.

Mechanical properties of carbon nanotube/carbon fiber reinforced thermoplastic polymer composite

Carbon nanotube (CNT)/carbon fiber (CF) hybrid fiber was fabricated by sizing unsized CF tow with a sizing agent containing CNT. The hybrid fiber was used to reinforce a thermoplastic polymer to prepare multiscale composite. The mechanical properties of the multiscale composite were characterized. Compared with the base composite (traditional commercial CF), the multiscale composite reinforced by the CNT/CF hybrid fiber shows increases in interlaminar shear strength (ILSS) and impact toughness. Laminate containing CNTs showed a 115.4% increase in ILSS and 27.0% increase in impact toughness. The reinforcing mechanism was also discussed by observing the impact fracture morphology. POLYM. COMPOS., 38:2001–2008, 2017. © 2015 Society of Plastics Engineers

Crashworthiness of carbon fiber hybrid composite tubes molded by filament winding

Carbon Fiber Reinforced Composites (CFRPs) with light weights absorbed a large quantity of energy through the progressive crushing modes by a combination of multi micro-crack including fiber fracture and matrix fracture, bending, delamination, splitting, friction and so on. High manufacturing cost of CFRPs was one of the most important reasons for not being used as energy absorption components in wide range. In this study, five types of tubes were manufactured by filament winding method and crashworthiness performance was investigated experimentally. The effects of crushing speed, temperature treatment, raw material and structure including hybrid ratio, fiber orientation and thickness of tube wall on energy absorption capabilities were investigated through quasi-static and dynamic compression tests. Optical microscope observation of cross sections was taken to analyze the mechanism of failure. A hybrid carbon/aramid FRP tube after temperature treatment exhibited the highest Es in quasi-static test (98kJ/kg in average) and dynamic tests (82kJ/kg in average), which have excellent energy absorption management.

The damping–modulus relationship in flax–carbon fibre hybrid composites

The trade-off between the elastic modulus and damping capacity as a function of fibre composition in carbon–flax hybrid composite laminates was investigated. Hybrid composite laminates with varying carbon–flax fibre–epoxy content were prepared using a combination of compression moulding and vacuum bagging. The elastic modulus and damping loss coefficients were determined by free-vibration in longitudinal and flexural modes, and modelled using a rule of hybrid mixtures (ROHM) and laminate theory. The models were in close agreement with the experimental data for both the longitudinal and flexural modes and thus appeared to be a feasible method of predicting the stiffness–damping relationship in this system of hybrid composite laminates. The experimental data of the tensile strength was found to also follow the ROHM. However, the experimental data of the flexural strength deviated negatively from the theoretical prediction, exhibiting lower values than the predicted ones.

Experimental and finite element studies of thin bonded and hybrid carbon fibre double lap joints used in aircraft structures

Finite element analysis (FEA) is performed to verify the static and fatigue strength of mechanically fastened, bonded and hybrid double lap joints. These joints are made from thin carbon fibre/epoxy laminates applied in aircraft structures. Several configurations are considered, including variations in rivet array and the addition of bondline defects. Adhesive nonlinear material properties, rivet surface contacts and frictional forces were included in the three-dimensional (3D) Finite Element (FE) models. The Multicontinuum Theory (MCT) is used to simulate the progressive failure process and the stress state for all specimens, whilst the strain energy release rate (SERR) as a function of crack length for bonded and hybrid specimens are also compared. Results have shown the FE models are able to accurately predict the bonded, riveted and hybrid joint strengths. The position of the first row of fasteners is critical in determining the crack growth rate. As the crack enters the fasteners' clamping zone there is a significant drop in SERR resulting in a much slower crack growth rate, therefore increasing the fatigue resistance of the hybrid joint configuration.

Removal of cadmium ion using micellar-enhanced ultrafiltration (MEUF) and activated carbon fiber (ACF) hybrid processes: adsorption isotherm study for micelle onto ACF

Micellar-enhanced ultrafiltration (MEUF) was applied to remove cadmium ion from wastewater using sodium dodecyl sulfate (SDS) as a micelle in this study. Investigations were carried out on operational parameters such as initial permeate flux, retentate pressure, initial cadmium concentration, pH solution, molecular weight cut-off (MWCO), and molar ratio of cadmium to SDS. Removal efficiency of cadmium increased with increase in retentate pressure, pH solution, and molar ratio of cadmium to SDS and decreased with increase in initial permeate flux. Higher removal efficiency of cadmium was achieved using lower MWCO. In optimized experimental condition, cadmium removal efficiency reached 75% within an hour. With MEUF–ACF hybrid process, removal efficiencies of cadmium and SDS were found to be over 99 and 90%, respectively. Freundlich isotherm equation fitted better with experimental results on adsorption of SDS by ACF than Langmuir isotherm equation. Overall SDS removal efficiency of ACF unit in series was 90%.

Controlling the wettability and adhesion of carbon fibers with polymer interfaces via grafted nanofibers

Interfacial properties in carbon fiber composites is one of the key parameters controlling their structural functionality. Here, we introduce a novel method to engineer carbon fiber-epoxy interfaces, via inclusion of nanofibers, towards higher interfacial strength and energy dissipation. In our method, thermally stabilized polyacrylonitrile (PAN) nanofibers are grafted onto carbon fibers via electro-spinning process, followed by nanofiber consolidation via solvent vapor and thermal treatment. These treatments partially dissolves nanofibers along the nanofiber-fiber interface and trigger entropic elasticity in nanofibers, thus, increasing the nanofiber-fiber interactions. The hybridization of carbon fibers with PAN nanofibers increased the interfacial shear strength (IFSS) by ∼48%, from 10.8 ± 2.6 to 15.9 ± 4.9 MPa. Postmortem fractography points to mechanical interlocking between nanofibers and epoxy and reinforcing effects of nanofibers in matrix as root causes of IFSS enhancement. As a result of adding nanofibers to carbon fiber, junction failure mode changes from a dominantly adhesive failure (at epoxy-fiber interface) to dominantly cohesive failure, and failure plane slightly shifts away from epoxy-fiber interface to within the epoxy. Compared to other types of whiskers grown on carbon fibers, such as CNTs, the method proposed here requires low temperatures (below 300 °C), during which no surface damages are expected to accumulate on carbon fibers.

Influence of deposited CNTs on the surface of carbon fiber by ultrasonically assisted electrophoretic deposition

The surface property of carbon fiber directly affects the interface performance between carbon fiber and matrix. To improve the surface property of carbon fiber, we proposed a simple method to prepare carbon nanotubes /carbon fiber hybrid fiber via ultrasonically assisted electrophoretic deposition (EPD). Surface morphologies and surface functional group of carbon fibers were examined by atomic force microscopy (AFM), scanning electron microscopy (SEM) and fourier transform infrared spectrometer (FTIR), respectively. The results show that the deposition of carbon nanotubes changed the surface morphologies of carbon fibers and introduced polar groups (C=O and C-O) to carbon fiber surface. Comparing the results with EPD-only, ultrasonically assisted EPD increased the uniformity of carbon nanotubes coatings whereas only sparse and not uniformly deposition formed without ultrasonic.

Interlaminar shear behavior of basalt FRP and hybrid FRP laminates

This paper focuses on the interlaminar shear behavior of basalt fiber reinforced polymer (FRP) laminates impregnated with epoxy and vinyl ester resins as well as hybrid basalt and carbon FRP laminates. Meanwhile, the interlaminar shear behavior of carbon and E-glass FRP laminates was also studied for comparison. The experiments were conducted according to the ASTM-D-2344 standard, and the failure modes, load–deformation (L–D) relationships, and interlaminar shear stress to normalized deformation relationships of various FRP laminates were analyzed. The differences in interlaminar shear behavior among different fibers and resins were identified. The fracture surfaces of the laminate specimens with different fibers were examined by scanning electron microscopy. Furthermore, the hybrid effect on interlaminar shear behavior was discussed and the interlaminar shear strength was predicted based on above analysis. The results show that the L–D relationships of FRP laminates can be classified into three types, which are determined by the interlaminar shear strength between fiber layers and the resin as well as by the failure modes. The interlaminar shear strength of basalt FRP with vinyl ester resin is higher than that of the glass FRP but less than that of the carbon FRP. The adoption of epoxy resin and the hybridization of basalt and carbon fibers can enhance the interlaminar shear strength of basalt FRP. In addition, the scanning electron microscopy images of fracture surfaces of the laminate specimens confirm the differences of interlaminar behavior of various composites. The hybrid effect on the interlaminar shear behavior is reflected in the integration of both advantages of basalt FRP and carbon FRP in the interlaminar shear stress to nominal deformation relationship, which results in both higher interlaminar shear strength at the cracking and the final stages. Finally, the interlaminar shear strength of different FRP laminates can be accurately predicted by the proposed model.

Investigation of the tensile properties of natural and natural/synthetic hybrid fiber woven fabric composites

The development of polymer composites containing natural fibers as a sustainable alternative material for certain engineering applications, particularly aerospace and automotive applications, is a popular area of research. In this study, the mechanical properties of flax, jute and jute/carbon woven fabric composites were investigated and compared with those of 3 K carbon woven fabric composites. The results of this study demonstrate the utility of natural fibers in composite applications. Furthermore, it is observed that the mechanical properties of natural fibres are significantly affected by changes in temperature. Experimental results prove that the mechanical properties of natural fiber composites are significantly lower than those of carbon fiber composites, but the hybridization of carbon and jute fibers can result in a composite material with enhanced mechanical properties.

Carbon Fiber/Carbon Nanotube Buckypaper Interply Hybrid Composites: Manufacturing Process and Tensile Properties

This paper reports on a study of carbon nanotube (CNT) thin film, or buckypaper (BP), integrated into carbon fiber (CF) prepreg composites to create hybrid composite materials with high CNT content. The autoclave process of manufacturing hybrid composite laminates was investigated to gain an understanding of nano/micro dual‐scale resin flow characteristics. The study found that resin bleeding along the through‐thickness direction was inhibited due to extra‐low permeability and high resin absorbing capacity of the BP. Resin matrix‐impregnated BP layers were much thicker than dry pristine BP due to high resin absorbency and swelling effects. The BP/unidirectional carbon fiber (UD‐CF) hybrid composites with local fiber volume fraction of 61.46 vol% in CF ply and local CNT volume fraction of 26.57 vol% in BP layer, had a tensile strength of 2519 ± 101 MPa and modulus of 149 ± 18 GPa. The dramatic improvements in both in‐plane and through‐thickness electrical conductivities demonstrate potential for both structural and multifunctional applications of the resultant hybrid composites.

Experimental analysis and theoretical modeling of the mechanical behavior of short glass fiber and short carbon fiber reinforced polycarbonate hybrid composites

In this research, polycarbonate (PC) composites with short glass fiber (SGF) and short carbon fiber (SCF) hybrid fiber reinforcements were compounded by single screw extruder and specimens were prepared by injection molding machine. This article aims to investigate the mechanical properties of PC hybrid composites, by means of the experimental and the theoretical methods. The composites were subjected to tensile test. Experimental results showed the improvements in tensile strength and modulus by increasing the SCF content of the hybrid composite. The theoretical tensile strength was predicted based on Kelly–Tyson model and rule of hybrid mixture. Kelly–Tyson model showed to be a good approximation to predict the tensile strength of composite. When the SCF was replaced by milled carbon fiber (MCF) to form a PC/SGF/MCF hybrid system, poorer mechanical properties are reported due to the weaker interfacial adhesion between MCF and PC, as proven by the scanning electron microscopy. POLYM. COMPOS., 37:1238–1248, 2016. © 2014 Society of Plastics Engineers

Synthesis of SnO2-activated carbon fiber hybrid catalyst for the removal of methyl violet from water

Abstract SnO 2 /activated carbon fiber (ACF) hybrid catalyst was synthesized from kapok precursor via a two-step process involving pore-fabricating and self-assembly of SnO 2 nanoparticles. The morphology and phase structure of the obtained samples were characterized by X-ray diffraction, field emission scanning electron microscope, high resolution transmission electron microscopy and N 2 adsorption-desorption isotherm. These results demonstrated that the synthesized SnO 2 /ACF retained the hollow-fiber structure of kapok fibers. SnO 2 nanoparticles dispersed uniformly over the ACF support. The obtained hybrid catalyst showed porous structure with high surface area (647–897 m 2 /g) and large pore volume (0.36–0.56 cm 3 g −1 ). In addition, the catalytic activities of the obtained samples for methyl violet degradation under microwave irradiation were also evaluated. It was found that the SnO 2 /ACF catalyst exhibited high catalytic activity for methyl violet degradation due to the synergistic effect of microwave and SnO 2 /ACF catalyst.