Effect of Processing Parameters on Bonding Performance of a Carbon Fiber/Polyetheretherketone Thermoplastic Composite Prepared by Induction Welding.

Among the various welding techniques used to bond thermoplastic composites, induction welding stands out as a fast, clean, and contact-free process that shortens the welding time and prevents the weight increase of mechanical fastening, such as rivets and bolts. In this study, we manufactured polyetheretherketone (PEEK)-resin-based thermoplastic carbon fiber (CF) composite materials at different automated fiber placement laser powers (3569, 4576, and 5034 W) and investigated their bonding and mechanical characteristics after induction welding. The quality of the composite was evaluating using various techniques, including optical microscopy, C-scanning, and mechanical strength measurements, and a thermal imaging camera was used to monitor the surface temperature of the specimen during its processing.

Manufacturing of Carbon Fibers/Polyphenylene Sulfide Composites via Induction-Heating Molding: Morphology, Mechanical Properties, and Flammability.

Conventional thermosetting composites exhibit advantageous mechanical properties owing to the use of an autoclave; however, their wide usage is limited by high production costs and long molding times. In contrast, the fabrication of thermoplastic composites involves out-of-autoclave processes that use press equipment. In particular, induction-heating molding facilitates a quicker thermal cycle, reduced processing time, and improved durability of the thermoplastic polymers; thus, the process cost and production time can be reduced.

A Facile Fabrication of Ordered Mesoporous Carbons Derived from Phenolic Resin and Mesophase Pitch via a Self-Assembly Method.

Ordered and disordered mesoporous structures were synthesized by a self-assembly method using a mixture of phenolic resin and petroleum-based mesophase pitch as the starting materials, amphiphilic triblock copolymer F127 as a soft template, hydrochloric acid as a catalyst, and distilled water as a solvent. Then, mesoporous carbons were obtained via autoclave method at low temperature (60 °C) and then carbonization at a relatively low temperature (600 °C), respectively. X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM) analyses revealed that the porous carbons with a mesophase pitch content of approximately 10 wt% showed a highly ordered hexagonal mesostructure with a highly uniform pore size of ca.

Relationship Between Functionalized Multi-Walled Carbon Nanotubes and Damping Properties of Multi-Walled Carbon Nanotubes/Carbon Fiber-Reinforced Plastic Composites for Shaft.

The mechanical properties and damping behavior of carbon fiber-reinforced plastic composites with functionalized multi-walled carbon nanotubes were examined. The functionalized multi-walled carbon nanotubes were blended with epoxy resins to prepare multi-walled carbon nanotubes/carbon fiber-reinforced plastic composites. The dispersion properties of functionalized multi-walled carbon nanotubes in epoxy resins were examined using surface free energy.

Hydrothermal Preparation of Ag/TiO₂/GO Nanocomposites with Ammonia-Treated Graphene Oxide for Enhanced Conductivity.

In this study, Ag/TiO₂/GO nanocomposites were successfully fabricated by a facile hydrothermal method. Nitrogen-doped GO was prepared using ammonia treatment to improve its conductivity. The Ag/TiO₂/GO nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), zeta potential, and photoluminescence spectroscopy (PL).

Oxalic acid assisted rapid synthesis of mesoporous NiCoO nanorods as electrode materials with higher energy density and cycle stability for high-performance asymmetric hybrid supercapacitor applications.

In this study, mesoporous nickel cobaltite (NiCoO) nanorods as electrode materials for high-performance hybrid supercapacitor were fabricated onto Ni foam by a simple and cost effective oxalic acid (OA) assisted rapid co-precipitation method. The effects of different metal precursors (NCO-Nitrate, NCO-Chloride and NCO-Acetate) on the electrochemical capacitive properties were studied. FE-SEM analysis confirmed that all samples exhibited highly dense mesoporous NiCoO nanorods vertically grown on the surface of Ni foam with excess accessible surfaces and unique sizes and morphologies.

Effect of Silane Coupling Agent on the Creep Behavior and Mechanical Properties of Carbon Fibers/Acrylonitrile Butadiene Rubber Composites.

In this study, we investigated the effect of the silane coupling agent on the relationship between the surface free energy of carbon fibers (CFs) and the mechanical strength of CFs/acrylonitrile butadiene rubber (NBR) composites. Moreover, the creep behavior of the CF/NBR composites at surface energetic point of view were studied. The specific component of the surface free energy of the carbon fibers was found to increase upon grafting of the silane coupling agent, resulting in an increase in the tensile strength of the CF/NBR composites.

One-Pot Synthesis of Ag-TiO₂/Nitrogen-Doped Graphene Oxide Nanocomposites and Its Photocatalytic Degradation of Methylene Blue.

In this study, we report Ag-TiO2/graphene oxide (GO) nanocomposites prepared by a simple one-pot synthesis using TiO2, AgNO3, and N-doped graphene (NDG). The NDG was synthesized using a microwave-assisted hydrothermal (MHT) method as a function of MHT time. The morphology and structure of Ag-TiO2/GO nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Raman, and Fourier-transform infrared spectroscopy (FTIR).

NiCoS nanosheet-decorated 3D, porous Ni film@Ni wire electrode materials for all solid-state asymmetric supercapacitor applications.

Wire type supercapacitors with high energy and power densities have generated considerable interest in wearable applications. Herein, we report a novel NiCoS-decorated 3D, porous Ni film@Ni wire electrode for high performance supercapacitor application. In this work, a facile method is introduced to fabricate a 3D, porous Ni film deposited on a Ni wire as a flexible electrode, followed by decoration with NiCoS as an electroactive material.

Hierarchically Assembled Nanofibers Created by a Layer-by-Layer Self-Assembly.

We report the hierarchically assembled nanofibers created by LbL self-assembly depending on the PSS-PAA fraction in the blend solutions and pH during bulid-up of the PAH/(PSS-PAA) multilayer films. The multilayer [(PEI/blend)/(PAH/blend)4] films with ρPAA (PSS-PAA fraction in the blend solutions) = 0.0 in the blend solution exhibited surface morphologies of randomly isolated globular clusters, while at ρPAA = 0.

Facile Synthesis of Core/Shell-like NiCo2O4-Decorated MWCNTs and its Excellent Electrocatalytic Activity for Methanol Oxidation.

The design and development of an economic and highly active non-precious electrocatalyst for methanol electrooxidation is challenging due to expensiveness of the precursors as well as processes and non-ecofriendliness. In this study, a facile preparation of core-shell-like NiCo2O4 decorated MWCNTs based on a dry synthesis technique was proposed. The synthesized NiCo2O4/MWCNTs were characterized by infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and selected area energy dispersive spectrum.

Effects of oxyfluorination on surface and mechanical properties of carbon fiber-reinforced polarized-polypropylene matrix composites.

In this work, oxyfluorination treatments on carbon fiber surfaces were carried out to improve the interfacial adhesion between carbon fibers and polarized-polypropylene (P-PP). The surface properties of oxyfluorinated carbon fibers were characterized using a single fiber contact angle, and X-ray photoelectron spectroscopy. The mechanical properties of the composites were calculated in terms of work of adhesion between fibers and matrices and also measured by a critical stress intensity factor (K(IC)).

Electrochemical characterization of a carbon nanofiber electrode system hybridized with PEDOT-PSS.

In this work, electrochemical properties of a bilayer electrode system prepared from an electrically conducting polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), PEDOT-PSS coated carbon nanofibers (CNFs), have been investigated. The CNFs were used as supports for the deposition of PEDOT-PSS by a dip-coating technique to yield a bilayer electrode system. Electrodes prepared by such a method were used in supercapacitors operating in acidic (1 M H2SO4) electrolytes.

Synthesis of mesoporous anatase TiO2 nanotubes by a hydrothermal treatment and their use in solid-state dye-sensitized solar cells.

Mesoporous anatase TiO2 nanotubes (NTs) with the diameter of about 7 12 nm and the length of several hundred nanometers were synthesized by a hydrothermal method on commercial TiO2 particles in NaOH followed by HCI washing. The samples were characterized by X-ray diffraction (XRD), transmitting electron microscopy (TEM), and Brunauer-Emmet-Teller (BET) measurements. The hydrothermal treatment temperature at 130 degrees C was shown to affect not only the extent of particle-to-sheet conversion, and thus the resulting structures of the NTs, but also the anatase-to-rutile transformation.

Preparation and characterization of ACs/TiO2 composite electrodes for improving the specific capacitance of electrochemical double-layer capacitors.

In this work, the energy storage composite electrodes were prepared by mixing activated carbons (ACs) modified with a nanosize titanium oxide (TiO2) through a means of ultrasonic vibration in ethanol solution for 30 min. We examined the cyclic voltammetry of the composite electrodes in an aqueous electrolyte, 1 M H2SO4. It was found that the specific capacitance of the composite electrodes measured in a range of 0-0.

Electrocatalytic properties of graphite nanofibers-supported platinum catalysts for direct methanol fuel cells.

Graphite nanofibers (GNFs) treated at various temperatures were used as carbon supports to improve the efficiency of PtRu catalysts. The electrochemical properties of the PtRu/GNFs catalysts were then investigated to evaluate their potential for application in DMFCs. The results indicated that the particle size and dispersibility of PtRu in the catalysts were changed by heat treatment, and the electrochemical activity of the catalysts was improved.

Surface characteristics of carbon fibers modified by direct oxyfluorination.

The effect of oxyfluorinated conditions on the surface characteristics of carbon fibers was investigated. Infrared (IR) spectroscopy results indicated that the oxyfluorinated carbon fibers showed carboxyl/ester groups (CO) at 1632 cm(-1) and hydroxyl groups (OH) at 3450 cm(-1) and had a higher OH peak intensity than that of the fluorinated ones. X-ray photoelectron spectroscopy (XPS) results for the fibers also showed that oxyfluorination introduced a much higher oxygen concentration onto the fiber surfaces than fluorination with F(2) only.

Effect of chemical treatment of Kevlar fibers on mechanical interfacial properties of composites.

In this work, the effects of chemical treatment on Kevlar 29 fibers have been studied in a composite system. The surface characteristics of Kevlar 29 fibers were characterized by pH, acid-base value, X-ray photoelectron spectroscopy (XPS), and FT-IR. The mechanical interfacial properties of the final composites were studied by interlaminar shear strength (ILSS), critical stress intensity factor (K(IC)), and specific fracture energy (G(IC)).

Studies on PAN-based carbon fibers irradiated by Ar+ ion beams.

In this work, the effects of Ar+ ion beam irradiation on carbon fibers were studied using tensile and surface analytical techniques. The single-fiber pull-out test was executed in order to characterize the fiber/epoxy matrix interfacial adhesion. The Ar+ ion beam was irradiated using an ion-assisted reaction (IAR) method in reactive gas conditions under an oxygen environment with 1 x 10(16) ions/cm(2) Ar+ ion dose (ID), 6 sccm blown gas flow rate, and different ion beam energy intensities.

Influence of surface characteristics of carbon blacks on cure and mechanical behaviors of rubber matrix compoundings.

In this work, the effect of chemical modification on the surface energetics and cure kinetics of carbon blacks (CBs) modified with KOH and C6H6 was investigated by contact angle and rheometer measurements, respectively. Also, the resulting mechanical properties of the CBs/styrene-butadiene composites were studied in terms of tensile and dynamic mechanical analysis. As experimental results, the polar basic and nonpolar chemical treatments showed an increase of the London dispersive component (gamma(S)(L)) of gamma(S) of the CBs without significantly changing the surface properties and microstructures that resulted from the deaggregation of microstructures and decrease of the swollen weight of the sample in the equilibrium state.

Influence of atmospheric plasma on physicochemical properties of vapor-grown graphite nanofibers.

Vapor-grown graphite nanofibers (GNFs) were modified by plasma treatments using low-pressure plasmas with different gases (Ar gas only and/or Ar/O2 gases), flow rates, pressures, and powers. Surface characterizations and morphologies of the GNFs after plasma treatment were investigated by X-ray photoelectron spectroscopy (XPS), contact angle, titration, and transmission electron microscopy (TEM) measurements. Also, the investigation of thermomechanical behavior and impact strengths of the GNFs/epoxy composites was performed by dynamic-mechanical thermal analysis (DMTA) and Izod impact testing, respectively.

Relationship between surface characteristics and interlaminar shear strength of oxyfluorinated carbon fibers in a composite system.

In this work, a direct oxyfluorination method was used to study the effect of oxygen content on surface and mechanical interfacial characteristics of oxyfluorinated carbon fibers in an epoxy matrix system. The changes of surface functional groups, chemical compositions, and structures of the carbon fibers were characterized by Fourier transform infrared spectrometer, X-ray photoelectron spectroscopy, and X-ray diffraction measurements. Also, the mechanical interfacial properties of the composites were evaluated by means of interlaminar shear strength tests.