The development of cost-effective electrocatalyst with high activity and durability for oxygen reduction reaction (ORR) in acidic condition is a key step towards the wide-spread application of proton exchange membrane fuel cells (PEMFCs), while the high cost of benchmark Pt/C is one of the main inhibiting factors. Here, we report a new composite catalyst by adopting electrocatalytically active Co,N-modified

High-k, UV curable polymer composites with low dielectric loss and high breakdown strength were prepared. Fluorosilane coupling agent (FAS-17) was adopted to modify the surface of BaTiO3 (BT) nanoparticles. Characterization results of UV-cured composites filled with [email protected] particles indicate that the dielectric loss is dramatically decreased and the breakdown strength is significantly improved

The influence of measurement temperature on the high velocity (>100 m/s) impact performance was investigated for three thermosetting epoxy resin S-2 glass composite systems. These three model resins were chemically similar but have different glass transition temperatures (Tg) and molecular weights between crosslinks (Mc) through the use of different diamine curing agents (Jeffamine® D230, D400, and

Hyperbranched epoxy resins (HERs) has attracted much interesting due to improving homogeneously the ductility and strength of popular diglycidyl ether of bisphenol-A (DGEBA), but the preparation of HERs/DGEBA composites with low-temperature resistance and rapid degradation is still a challenge in the sustainable development of thermoset field. Here we represent self-curable hyperbranched epoxy resins

Although 3D woven composites have exceptional out-of-plane properties, there is a lack of understanding for these materials in crash application in automotive and aerospace industries. To encourage the use of 3D wovens in crashworthy automotive structures, knowledge must be gained so that designers can adjust the highly flexible weave parameters to create tailor-made performance materials. Here we

An efficient strategy was developed to prepare the linear cylinder-like carbon fiber @ room temperature vulcanized silicone rubber ([email protected]) core-sheath elastomer as the high-performance additive of PRC with the purpose of improving the wear-resisting performance of phenolic resin composites (PRC). Results showed that the recovery of the modified PRC was improved by 27.14%. The friction coefficient

The results, findings, and analytical investigation of an experimental study conducted on the hydrostatic implosion of filament wound carbon fiber epoxy composite tubes within partial confinement are presented. Implosion in geometries varying in length and diameter is initiated within a tubular confining structure with one end closed and one end open to a free-field, hydrostatic environment. Structural

The critical issue and challenge in reusing recycled carbon fiber (rCF) was to fully exerting its outstanding properties via an efficient and environmental-friendly way. In this study, the strengthening effects of polydopamine surface-modified recycled short CF (pDop-rSCF) on mechanical, thermo-mechanical, electrical and electromagnetic properties of epoxy (EP)-based composites were systematically

Hierarchical hollow structures have received considerable attention for light weight microwave absorption materials, however, constructing and regulating hollow structures with heterogeneous interfaces still remains a great challenge. In this work, hierarchical hollow [email protected]2 nanoboxes with double shells have been designed by a template-assisted process inspired by Pearson's hard and soft

Nanodiamond (ND) surfaces were successfully modified using the ozone treatment and tetraethylenepentamine (TEPA) solution for use as reinforcement in epoxy nanocomposites. The main purpose of the project was to introduce ozone/TEPA-functionalized NDs within the epoxy matrix to improve its thermal conductivity and fracture resistance by enhancing interfacial interactions. To confirm the efficacy of

The microstructure of the dactyl club of mantis shrimp is mainly divided into two regions, the impact region and the periodic region, which their synergy make the dactyl club have better impact resistance. It is provided innovative inspiration by two regions cooperation for the manufacture of high-energy absorption and impact-resistant fiber composite laminates. In this paper, a novel dactyl-inspired

In order to explore the dependence of mechanical properties on the microstructure of high-textured (HT) pyrolytic carbon (PyC), the microstructure and properties of HT PyC specimens prepared by isothermal isobaric chemical vapor infiltration (ICVI) and thermal gradient chemical vapor infiltration (TCVI) processes were investigated. The HT PyC of ICVI was uniform and exhibited a more distinct long-range

Al2O3 ceramic was added to a CaO–B2O3–Al2O3–SiO2 glass system to improve mechanical properties and thermal cycle stability in solid oxide fuel cell composite seals. The performance of glass-based seals with different Al2O3 content was evaluated, including the shear strength and leakage rate of the composite seals. The results showed that HA80 composite seal, with 20 wt% Al2O3, had excellent joint strength

This paper is granted with a novel method for improving the toughness of phenolic composite laminates. This method employs electrospun hybrid nanofibers containing polyvinyl butyral (PVB) and pyrolytic carbon (PyC), which are interleaved between mid-layers of the laminate. Mode-II fracture test is used for studying the toughening behavior of modified laminates. The results suggest shortage of pure

An accelerated testing methodology (ATM) for measuring CFRP laminate durability developed by the authors over many years is reviewed in this paper. First, the applicability of ATM to static, creep, and fatigue strengths of various load directions for CFRP laminates of various kinds is examined experimentally based on time–temperature superposition principles for matrix resin viscoelasticity. Second

Thermally conductive ternary poly (vinylidene fluoride) (PVDF)-based dielectric materials were fabricated via engineering the filler networks using hexagonal boron nitride (hBN) nanosheets and surface functionalized silicon carbide (f-SiC) nanowires. The hBN nanosheets and f-SiC nanowires synergistically improved the thermal conductivity of the composites, in a way that parallelly oriented f-SiC nanowires

The current study focuses on the bearing failure process of NCF composites and associated damage mechanisms. A set of experiments on bolted joints between NCF composite and steel plates have been performed. The bearing damage onset and failure progression in the composite was monitored at different load levels by microscopic image analysis. Fibre kinking in 0° layers was found as the key damage mechanism

The recent development of nanoscience and nanotechnology enables the synthesis of nano-particles of non-ellipsoidal shape. In this study, to tackle the various inclusion topologies in the framework of micromechanics, the numerical surface integration was used to evaluate the volume-averaged Eshelby tensor for superspheral and superellipsoidal inclusions in isotropic elastic material. By taking advantage

“Quilted Stratum Process” (QSP ®) is a new process in the category of thermoplastic composite forming with the objective to locally strengthen the composite parts by strategically stacking discontinuous UD/woven prepregs while maintaining the short cycle time of about 1 min. Interply adhesion arising due to polymer tack plays an important role in QSP ® due to the presence of resin-rich layer at the

The aim of this work is to study the prospects of using Co/CoCo2O4 nanowires as catalysts for the reduction reactions of para-nitroaniline to para-phenyldiamine, as well as CO conversion. Interest in these structures is due to their physicochemical properties, spinel structure, leading to an increase in catalytic activity, high stability to external influences and degradation over a long period of

Weak interfacial interactions always restricted and weakened the properties of the composite materials and constituted a primary bottleneck. Herein, under the guidance of bioinspired engineering thought and inimitable structural features of hyperbranched polymers (HBPs), a series of designed multilevel core-shell 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) particles by in-situ grafting HBPs on polydopamine

Pultruded fiber-reinforced polymer (FRP) composite is expected to be applied for infrastructures widely due to its advantages of lightweight, anti-corrosion, and industrial manufacturing. Its long-term performance has attracted increasing attention from academia and industry. This paper presents A comprehensive review on experimental studies investigating the mechanical performance of pultruded FRP

Considering the reduction of fire hazards associated with the application of epoxy resin (EP) composites. Herein, a novel sodium-containing polyhedral oligomeric phenyl silsesquioxane (Na-Ph-POSS) has been synthesized through hydrolysis condensation. FTIR, NMR and MALDI-TOF MS results reveal that Na-Ph-POSS is a hepta-phenyl POSS consisting of Si–O–Na and Si–OH groups. Compared to pure EP, according

In this paper, a new proposed radar-absorbing honeycomb sandwich composite with nickel-coated glass fabric, implemented via electroless plating, was applied to the leading edge of a NACA 0012 wing airfoil model to reduce the echo radar cross-section (RCS) level. The composite was designed and fabricated without dispersing conductive nanoparticles or metal magnetic micropowders in polymer materials

In this paper, a kinetic model able to predict the evolution of the through-thickness degree of cure of ultraviolet (UV) cured composites has been developed and validated. The kinetic model, which is based on the autocatalytic model, depends on the temperature of the composite and the absorbed intensity by the photoinitiators. This intensity is calculated by an optical model divided into discrete values

The fatigue crack propagation mechanism of a TiB2-reinforced high-modulus steel fabricated by eutectic solidification process was investigated for the first time. The fatigue crack growth rate (FCGR) of the TiB2-reinforced steel was measured by using in-situ scanning electron microscope (SEM) and it was compared with that of a low carbon ferritic steel. It showed that the FCGR of TiB2-reinforced steel

Exploring new types of absorbing materials has always been the focus and hot spot of stealth research. As we all know, the best conductivity of absorbing materials is generally in the range of semiconductor. Polyoxometalate is a kind of metal oxygen cluster with semiconductor properties and a good electron acceptor, but there is little research on its absorption property. In this work, we synthesized

This paper presents a numerical approach using the discrete element method to predict strength and damage propagation of plates and bolted lap joints subjected to axial tension. Tensile tests on GFRP plates and bolted joints are carried to obtained their overall stiffness and strength. A new three-dimensional discrete element model constructed by a 19-ball assembly is proposed and the relationships

The aim of this paper is to evaluate the influence of sustainable surface treatments —performed on flax nonwoven fabrics as textile reinforcement— on the durability of calcium aluminate cement (CAC) based composites. Two treatments are considered: an alkaline treatment (for increased stability and adhesion), and a treatment with soybean oil (for a higher hydrophobia to reduce fiber degradation). The

Thermal interface materials (TIMs) are essential components to deplete the accumulated heat with efficient thermal management in the majority of power electronic systems such that the interfacial thermal resistance (ITR) should be significantly reduced. A reduced percolation threshold of hybrid fillers of ball-milled exfoliated graphite nanoplatelets and AgNWs are used for enhanced thermal interface

Spatial deviations in composite braid unit cell dimensions limit mechanical performance and are challenging to model. Full-field measurements of the irregular tow placement in biaxially braided composite tubes were obtained by digital image correlation. Analysis of the reconstructed tow paths showed long-range defects along the hoop direction with short-range defects dominating the biased tow direction

Thin-walled composite structures operating in the post-buckling regime needs a thorough understanding of their stability behavior and failure mechanisms. For the accurate prediction of the collapse loads, one needs to account for the damage evolution precisely. In the current study, we have proposed a unified and generic numerical modeling approach that accounts for both the intra and inter-laminar

A sort of biodegradable magnesium-based nanocomposites improved by nano-sized NiTi particles has been offered in the current research with the evaluations for implant application. The samples were provided through mechanical alloying followed by sintering; the assessments consisted of microstructure, mechanical properties, and in-vitro biocompatibility. The impacts of integrating 15, 30, and 45 wt%

Developing ultrathin, lightweight, flexible and efficient electromagnetic interference (EMI) shielding materials is still a long-standing issue. Herein, a series of biomass derived carbon composite films with superior EMI shielding performance are reported. The cotton derived carbon fabric wrapped with CoFe alloy nanoparticles ([email protected]) was prepared by pyrolysis at temperature of 600–800 °C

Fiber reinforced cementitious materials, when exposed to a fire, can have better residual mechanical properties than plain cementitious materials, particularly the tensile property. One critical factor governing the residual bridging effect is the fiber-matrix bond performance. However, the effect of temperature on the residual interfacial bond performance remains poorly understood. Here, based on

This study describes buckling instabilities mediated via surface roughness to generate hierarchical structures on a metal (aluminum)/polymer (polystyrene) laminated composite bilayer film on a rigid substrate. Buckling instability is a non-lithographic approach to generate microscale features in thin films. Metals can buckle over the surface due to compressive stress arising from differences in thermal

Base isolation is an efficient method to reduce the vulnerability of structures in high seismic risk zones. As the core component, the performance of the isolation bearings greatly affects the safety and reliability of the isolation system. In this paper, a series of compression shear tests were performed on three scaled rubber bearings, test temperatures range from −30 to 20 °C and different levels

PrBaCo2O5+σ-BaZr0.1Ce0.7Y0.1Yb0.1O3 (PBC-BZCYYb) composite cathodes are prepared by repeating impregnation (up to 5 times) of PBC into BZCYYb scaffold for proton-conducting solid oxide fuel cells with Ni-BZCYYb anode and BZCYYb electrolyte. The single-cells are evaluated electrochemically at temperatures between 600 and 750 °C using humidified hydrogen (∼3% H2O) as the fuel and air as the oxidant,

The objective of the current work is the development of a numerical framework for the simulation of damage in composite structures using explicit time integration. The progressive damage is described using a Continuum Damage Mechanics (CDM) based material model, CODAM2, in which the damage initiation and progression are modelled using Hashin's failure criteria and crack-band theory, respectively. The

In this work, laser surface treatment and laser induced breakdown spectroscopy (LIBS) were combined to improve process control of surface treatment and pre-bond surface characterization to measure the reduction in silicone content. This approach addresses guidelines provided by the Federal Aviation Administration (FAA) in Advisory Circular 20–107B focused on improved process controls, as well as the

Application of fiber reinforced polymer (FRP) cables on long-span cable-supported bridges can overcome the disadvantages of traditional steel cables such as heavy weight, obvious sag effect, decreasing carrying efficiency, pronounced fatigue degradation, and serious corrosion damage. On the basis of theoretical analyses and experimental studies on the application of FRP cable in long-span cable-supported

With the purpose to obtain an eco-friendly flame retardant for epoxy resin, a facile method for the synthesis of a bio-based epoxy monomer containing DOPO units (DGEBDB) from lignin-derived vanillin and guaiacol, was presented in this work. During the synthesis process, guaiacol acted as both reactant and solvent. And it could be recycled in situ and re-used as the fresh one. In order to evaluate the