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We report on the studies of conduction mechanism, direct current conductance, and 1 f -noise of cellulose nanofiber (CNF) and multiwalled carbon nanotube (MWCNT) composites. The composites were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The temperature- and voltage-dependence of the dc conductance Σ were, respectively, probed to investigate the charge transport mechanism and the electrical response of the composite. At room temperature, the increase in Σ with wt. % of MWCNT ϕ showed typical percolation behavior. The Σ − T behavior was fitted to the combination of one-dimensional variable range hopping and the fluctuation-induced tunneling, which were attributed to hopping of charge carriers through 1D MWCNTs and the tunneling of charge carriers between the bundles of MWCNTs, respectively. The non-Ohmic electrical conduction was characterized by the onset voltage V 0 (T) which scaled with Ohmic conductance Σ 0 as V 0 (T) ∼ Σ 0 (T) x T , with x T being the onset exponent increased with ϕ. A scaling description based on the data collapse method was adopted to find the parameters V 0 (T) and x T. The noise power spectrum S V (f) followed the relation S V (f) ∼ V β with two different power-laws: β 1 in the Ohmic and β 2 in the non-Ohmic region (β 1 > --> β 2). Interestingly, this change in power-laws occurs at the same V 0 (T) obtained from Σ − V curves. A simple model was proposed to explain the noise behavior after V 0 (T). It is expected that such electrical characterization of CNF-MWCNT nanopaper composite would open up their possibility of application in flexible electronic devices, intelligent networks, sensors, and actuators. [ABSTRACT FROM AUTHOR]

Based on the analysis of the structure and force characteristics of the composite tube, the feasibility of the finite element model is verified by conducting a quasi-static hydrostatic test on the new composite body tube combining carbon fiber composite material and metal lining, and comparing the ABAQUS finite element simulation to simulate the gradual damage and failure of the composite cylinder under hydraulic load. Based on the verified finite element model, the influence of single-angle spiral padding and multi-angle gradient spiral alternating padding on the pressure-bearing performance of composite tube is deeply explored, and the numerical analysis results show that the multi-angle gradient spiral lay-up method can make the composite tube show better performance. Based on the premise of this ply method, the univariate method was used to study the influence of carbon fiber grade on the pressure bearing performance of composite tube. [ABSTRACT FROM AUTHOR]

Feather shaft is a fiber reinforced lightweight bio-composite materials with good strength and toughness. It provides possibility for the design of carbon fiber composite that combine rigidity and flexibility, and the key to achieve this is to study the corresponding mechanical gene. Here, inspired by the ring array fiber in the feather shaft, a carbon fiber composite was designed. Through experimental investigation, the "ring array" induced shear strain shielding, progressive damage caused by shear strain reversal and "rigidity-flexibility balance" caused by progressive damage was revealed, which will help establish an approach from structure to mechanical properties through strain and damage. [ABSTRACT FROM AUTHOR]

A novel bistable symmetric laminate of pure carbon fiber composite is presented in this article. First, an analytical model was established based on the results of finite element analysis (FEA) using the segmented continuous displacement function. Then, the bistable pure carbon fiber composite symmetric laminate was prepared in the experiment. Both the analytical and FEA results are in considerable agreement with the experimental results. Finally, the effects of various laminate lengths, widths, ratios, thicknesses and materials were investigated. The results showed that the bistable pure carbon fiber composite symmetric laminate has larger deformation and lower snap-through load. [ABSTRACT FROM AUTHOR]

The present study reports the development of ternary and quaternary carbon nitride (CN) based nanocomposites through the coupling of CN with single-walled carbon nanotubes (SWCNTs), Ag3PO4 (AP) and Ag nanoparticles (NP). A facile wet-chemistry process was developed for the synthesis of the composites. The prepared materials were characterised using XRD, ATR, DR-UV-Vis, photoluminescence (PL) spectroscopy and EPR. Photocatalytic dye degradation (rhodamine b, RhB) is greatly improved in composite materials. The most active photocatalyst was the quaternary composite bearing SWCNTs, Ag3PO4 and Ag NP, that presented a 2- and a 3-fold increase in photoactivity compared with the CN functionalised only with SWCNTs and the pure CN, respectively. The enhanced activity is associated with improvements in several important materials properties. Adsorption in the visible light is improved by the presence of Ag3PO4 and Ag NP. The latter provided plasmon resonance effects, absorbing light up to 700 nm. The presence of SWCNTs reduced charge recombination phenomena reducing by half the PL intensity. In addition, charge availability was further increased due to the formation of heterojunctions through the coupling of CN with Ag3PO4 and Ag NP. The PL intensity of the ternary composite was reduced to 1% of the pure CN PL intensity. In-situ EPR spectroscopy using spin-traps revealed the formation of superoxide anion radicals ($${\rm{O}}_2^{ \bullet - }$$ O 2 ∙ − ) that provide evidence for charge transfer via a Z-scheme mechanism. $${\rm{O}}_2^{ \bullet - }$$ O 2 ∙ − production was enhanced 8.5 times in the ternary composite compared with the pure CN. The importance of the stepwise functionalization of CN through the formation of ternary and quaternary composites towards the development of advanced photoactive materials is highlighted herein. [ABSTRACT FROM AUTHOR]

The design of the torsion-loaded toroidal shell segment with two functionally graded carbon nanotube-reinforced composite (FG-CNTRC) coatings and the corrugated core is presented. Round and trapezoidal shapes of the corrugated core are considered. A homogenization model for the corrugated core is applied to predict the stiffnesses of the corrugated core. The total potential energy equation, according to the Donnell shell theory, is established. The Ritz energy method is applied to determine the expressions of the buckling and postbuckling responses. The numerical investigations present the significantly beneficial effects of FG-CNTRC coatings and corrugated core on the buckling responses of the shells. [ABSTRACT FROM AUTHOR]

Silicone rubber (SR) is an ideal dielectric elastomer substrate due to its excellent flexibility and fast response speed. However, the innate low dielectric permittivity (ε) of SR generally requires a rather high driving voltage that restricts its widespread application. Typical attempts to increase ε of SR usually deteriorate either its flexibility or electrical stability. Herein, conductive multi‐walled carbon nanotube (MWCNT) were first surface modified with polyphenols (PNs) (MWCNT@PNs), aiming to facilitate its well dispersion within SR matrix, which may maintain the softness and electrical stability of SR via suppressing concentrated physical crosslinking and local leakage current flow. Then, five‐layered MWCNT@PNs/SR composites were prepared with the outer two insulating layers of SR while middle three dielectric layers of MWCNT@PNs filled SR. The multilayered structure further hindered the formation of conductive pathways through the composites, promising a high breakdown strength of the composites. Therefore, the multilayered MWCNT@PNs/SR composites exhibited increased ε, maintained low Young's modulus and electrical breakdown strength compared with pure SR of the same five‐layered structure. Among them, the composite with uniformly distributed MWCNT@PNs (m‐1: 1: 1) showed a highest actuation strain of 11.9% (at 19.6 kV mm−1), which was 4.1 times higher than that of SR (2.9% at 19.1 kV mm−1). [ABSTRACT FROM AUTHOR]

Carbon/carbon (C/C) composites have strict requirements for their thermal properties in extreme environments, especially at high temperature, where their properties are crucial for long-term life. The structure of C/C composites is exceptionally complex and exhibits multi-scale characteristics, and their thermophysical properties are closely related to temperature. Therefore, exploring their thermal response and heat transfer mechanisms through experimental method is relatively costly. This paper constructs a multi-scale finite element model to investigate the influence of structure and manufacturing defects on performance, and analyzes the thermophysical properties of the composites at High-temperature. By constructing a micro-representative volume element (Micro-RVE) that includes fibers, matrix, and pores, and using a steady-state heat transfer analysis method, the influence of material phase distribution on performance is studied. At the same time, a Meso-RVE reflecting the layering form, needle punching effect and manufacturing defects is established, and the transient heat transfer analysis method is used to investigate the influence of the structural form on performance. Finite element analysis shows that, the simulation values of the three C/C composites of unidirectional fiber bundles, short-chopped fiber felts, and needle punched C/C composites show good consistency with the experimental results in the published literature. This paper uses numerical methods to calculate the thermophysical properties of C/C composites from room temperature to 900°C and explores their variation with temperature. The constructed multi-scale model provides an accurate and effective method for predicting the thermophysical properties of C/C composites and also provides new perspectives and insights for thermal-mechanical coupling analysis and structural design. [ABSTRACT FROM AUTHOR]

This paper aims at investigating 1/2 and 1/3 subharmonic resonances of a rotating functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beam in the presence of geometric imperfections. A general function is introduced to denote three types of imperfections containing sine, global, and local modes. At first, based on the von-Kármán geometric nonlinearity assumption, the forced vibration equation is set up. Then, the Galerkin method and multiple scale method are utilized to study subharmonic resonance behaviors. Finally, coupled effects of FG-CNTRCs, rotating motion, and geometric imperfections on subharmonic resonance responses are investigated. It is found that a specific range of the excitation amplitude and frequency motivates the subharmonic resonance behavior. The coupling of geometric imperfections and geometric nonlinearities generates the 1/2 resonance phenomena, and geometric nonlinearities result in the 1/3 resonance behavior. Both the imperfection mode and amplitude can affect the resonance response and resonance regions. Moreover, in contrast with the 1/3 subharmonic resonance, geometric imperfections produce greater influence on the 1/2 subharmonic resonance. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel embedded KVO 3 /NC anode is developed with 3 Li+ insertion/extraction mechanism. • A series of in-/ex-situ characterizations and DFT calculations clarify the reaction mechanism and structure–activity relationship. • KVO 3 /NC anode can deliver unparalleled electrochemical performances in both half- and full-cells. Vanadium-based metallic salts, characterized by their intrinsic low electronic conductivity, are impeding their advancement as anode materials in the realm of lithium-ion battery technology. This study presents a novel embedded anode material KVO 3 /NC (KVO/NC) synthesized via a sol–gel method, with KVO 3 (KVO) particles in situ growing on N-doped carbon, thereby ameliorating conductivity and electrochemical performance. The findings reveal that KVO/NC composite has three lithium-ion storage sites, ultra-high cycling stability (289 mA h/g@5000 cycles@10 C@100 %), and superior rate performance (249 mA h/g@15 C; 221 mA h/g@20 C). Coupled with LiFePO 4 cathode, it achieves a competitive energy density (391 W h kg−1@0.1 C; 1–3.9 V). This work reveals the practical potential of KVO/NC as a new type of lithium-ion battery anode material with high energy density and long cycle life through a series of ex situ/in situ characterizations. [ABSTRACT FROM AUTHOR]

The unique morphology of thermoplastic vulcanizates (TPVs) reveals a significant correlation between the microstructure and performance, and the development of high‐performance TPV composites for specialized applications has become a current research priority. This study is devoted to developing heat‐ and oil‐resistant TPV composites filled with carbon black (CB) based on hydrogenated acrylonitrile butadiene rubber (HNBR) and thermoplastic polyester elastomer (TPEE) following the masterbatch procedure of dynamic vulcanization. Herein, it focuses on the effects of CB content on the morphology, filler network structure, and properties of the TPV/CB composites. As observed by morphological studies, CB nanoparticles are interconnected and aggregated to form a dual network structure of rubber and CB particles in the composite. With the increasing CB content, it's demonstrated that dual networks have enhanced and shifted to rigid. Consequently, the hardness, thermal stability, and oil resistance of TPV/CB composites are improved, with a 104% elevation in the stress at 300% strain. The flowability in the molten state, toughness (the elongation at break decreased from 690% to 310%), and elasticity deteriorated by oversized (0.5 ~ 1.2 μm) CB agglomerates and rigid rubber particles. This study gives new insight into the microstructure‐properties relationship of TPVs, offering theoretical guidance for fabricating HNBR‐based TPV composites. [ABSTRACT FROM AUTHOR]

Sandwich composites consist of two external face sheets and an inner core, offering enhanced strength, stiffness, and weight efficiency. While widely used across industries like construction, marine, automotive, and aerospace, they do have drawbacks such as buckling, low damage resistance, and delamination. This study focused on fabricating two sandwich composite plates using the vacuum infusion method, with PVC foam as the core and glass fiber face sheets and epoxy resin as the binding agent. One plate had carbon fibers interwoven into the core to improve interfacial fracture toughness and low‐velocity impact resistance. Testing based on ASTM standards revealed significant enhancements with the addition of interwoven carbon fibers. The composite with carbon fibers exhibited a 98.26% increase in interfacial fracture toughness and a 22.368% increase in peak force during low‐velocity impact, indicating superior load‐bearing capacity. Moreover, it demonstrated a 2.08% improvement in total energy absorption and a 9.83% increase in total deformation compared to the standard composite material. These findings highlight the effectiveness of integrating carbon fibers into sandwich composites for enhanced performance under varied conditions. Highlights: Two sandwich composite sheets were manufactured using vacuum infusion processOne sheet consisted carbon fiber interwoven in the core material of the compositeInterfacial fracture toughness test was conducted using modified three‐point bend testLow velocity impact test was performed for the two specimensThe results of the two tests for both the specimens were compared and evaluated [ABSTRACT FROM AUTHOR]

Interfacial and thermal conductivity issues of carbon fiber composites pose key challenges that restrict their application in the industry. Hence, we prepared an aqueous sizing agent modified with nanosol of boron nitride (BN) and carbon nanotube (CNT) hybrids using sol–gel method to synergistically enhance the interfacial performance and thermal conductivity of carbon fiber (CF) composites. Compared to the unsized CF composites, the interlaminar shear strength (ILSS), interfacial shear strength (IFSS), flexural strength and thermal conductivity of the sized composites were increased by 47.0%, 41.4%, 51.0% and 49.5%, respectively. This was attributed to the fact that the BN/CNT nanoparticles contained in the sizing agent increased the specific surface area of the fibers, enlarged the interfacial phase region for stress transfer, and facilitated the formation of strong chemical/physical interactions among the fibers and resin. Additionally, BN and CNT nanoparticles formed a three‐dimensional thermally conductive network on the fiber surface, which promoted the formation of a good heat transfer path between the fibers and resin. This work presents an effective strategy for fabricating CF composites with exceptional mechanical performance and thermal conductivity. Highlights: A BN/CNT nanohybrid sol is prepared by sol–gel method.A sizing agent is fabricated by modifying WEP through BN/CNT nanohybridised sols.Sizing agent promotes a good thermal conductivity path between CF and resin.Sizing agent enhances the mechanical properties of CF composites. [ABSTRACT FROM AUTHOR]

Due to the exceptional flame retardancy, environmental protection, cost‐effectiveness, and ease of processing, halogen‐free flame‐retardant polyethylene (PE) composites are attracting wide attention. However, the addition of halogen‐free flame retardants usually leads to significantly decreased mechanical properties of PE composites, which greatly limits its application. Herein, we report a halogen‐free flame‐retardant PE/ethylene‐vinyl acetate copolymer composite (PE/EVA) with excellent flame retardancy and mechanical properties by combining compatibilizer, crosslinking agent, and carbon fiber. The presence of compatibilizer not only improves the compatibility of halogen‐free flame retardants and matrix, but also interacts with the crosslinking agent to form a cladding structure on the surface of carbon fiber. The enhanced interaction between carbon fiber surface and matrix then results in significantly enhanced flame retardancy and mechanical properties of the composite. Specifically, adding 4 phr compatibilizer, 0.5 phr crosslinking agent, and 10 phr carbon fiber will lead to the halogen‐free flame‐retardant PE/EVA composite with a UL‐94 V‐1 level, limiting oxygen index of 27.1, and an increased tensile strength by 84.02% reaching 19.12 MPa. Moreover, further carbon fiber surface modification can further enhance the flame retardancy of the composite probably due to a synergistic flame‐retardant effect caused by the surface modified nitrogen and silicon elements. As a result, the composite achieves UL‐94 V‐0 level and the limiting oxygen index of 27.7 with well‐retained high tensile strength of 15.19 MPa. This work provides a practical strategy for enhancing the flame retardancy and mechanical property of PE‐based composite simultaneously. Highlights: Compatibilizer interacts with crosslinking agent to form a cladding structure on the surface of carbon fiber.Crosslinking agent promotes the formation of chemical bonds between modified carbon fiber, compatibilizer, and matrix.Carbon fiber surface modification can enhance the flame retardancy of the composite due to the synergistic flame‐retardant effect. [ABSTRACT FROM AUTHOR]

In this work, we synthesized composites of ferrous disulfide and tin disulfide with multi-walled carbon nanotubes (MWCNTs) using a straightforward hydrothermal method. The incorporation of carbon nanotubes significantly enhanced the dielectric loss capability of the composites. When the filling ratio of FeS2/SnS2@CNTs (20 wt%) in paraffin was 40%, the effective absorption bandwidth was 3.28 GHz, while the minimum reflection loss (RL) value was as high as −39.2 dB, which corresponded to a thickness of only 1.4 mm. This work reveals the potential research value of this material in terms of thin thickness, strong absorption and light mass. [ABSTRACT FROM AUTHOR]

Highlights The demand for increased distribution capacity in transmission lines has led to the growing use of hybrid composite rods as the reinforcing core of Aluminum Conductor Composite Core overhead conductors, known as ACCC. These rods usually consist of a carbon fiber‐reinforced epoxy matrix composite core surrounded by an outer shell made of a glass fiber‐reinforced epoxy matrix composite. The outer shell composite can be reinforced with basalt fibers, which are being used more frequently due to their favorable properties. In this research, mechanical properties such as flexural strength, physical properties including density and electrical resistance, and thermal behavior of carbon/basalt/epoxy (CBE) and also carbon/glass/epoxy (CGE) hybrid composite rods fabricated by the pultrusion process have been investigated. The CBE composite exhibited approximately 4% higher mean flexural strength than CGE. Additionally, the CBE composite showed higher thermal stability, as indicated by Thermogravimetric Analysis (TGA). The CGE composite has about 4% higher density than the CGE composite, leading to higher mass per unit length of the resultant ACCC conductor. Finally, the fracture surfaces of hybrid composite rods have been studied using scanning electron microscopy (SEM). The results indicate the better mechanical and thermal properties of carbon/basalt/epoxy hybrid composite rods. Growing use of hybrid composite rods in ACCC overhead conductors. Hybrid composite rods have a carbon fiber core and glass‐reinforced outer shell. Basalt fibers increasingly used to reinforce the outer shell composite. Pultrusion process used for producing the hybrid composite rods. Fracture surfaces of hybrid composite rods studied using SEM. [ABSTRACT FROM AUTHOR]

Developing bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) through simple, economical, and innovative methods is vital for sustainable energy conversion. Here, we showcase a green and sustainable approach for synthesizing CuCo₂O₄ - Sargassum Tenerrimum derived carbon composites (CCST) directly from fresh seaweed and a deep eutectic solvent (DES), marking its initial application in HER/OER. The successful transformation of seaweed and metal precursors into CCST was accomplished using a direct pyrolysis method at 900 °C in an inert atmosphere. Here, Seaweed granules acted as the carbon source, with DES employed for its multifunctional properties, including serving as a solvent, a structural template, and a catalyst for fostering material development. When these materials were assessed as electrocatalysts for OER in 1 M KOH media, the optimal catalyst (CCST-9 (1:2)) exhibited a low overpotential of 381 mV at 10 mA cm−2 with a Tafel slope of 44 mV dec−1. In addition, the same material achieved low overpotential of 383 mV at 10 mA cm−2 with a Tafel slope of 100 mV dec−1 when tested as an electrocatalyst for HER in 0.5 M H 2 SO 4 media. Interestingly, CCST-9 (1:2) demonstrated excellent long-term stability in OER in 1 M KOH during a 24-h chronoamperometry test, with only a minor reduction in current density. The present study contributes new perspectives to the development of scalable and high-performance bifunctional catalysts, achieved through an environmentally friendly and cost-effective synthetic strategy. • This study uses abundant, sustainable marine biomass as an eco-friendly carbon source for synthesizing efficient electrocatalysts. • A green solvent, DES, was utilized as both a structural template and catalyst for material development. • The synthesis approach is sustainable, cost-effective, and amenable to scalability, enhancing its practical applicability. • The synthesized electrocatalysts demonstrated exceptional electrocatalytic activity. [ABSTRACT FROM AUTHOR]

The integration of electrospun nanofibres into composite materials such as carbon fibre reinforced polymers (CFRP) and glass fibre reinforced polymers (GFRPs) has gained significant attention for enhancing their mechanical and thermal properties. This study focuses on the impact of incorporating polyacrylonitrile (PAN)-based nanofibres into an epoxy matrix to form multi-layered laminate composites. Our approach involved interleaving these orientated nanofibres within CFRP/GFRP matrices to investigate improvements in bulk material characteristics. The tensile and thermal properties of the resulting nanocomposites were thoroughly analysed. Thermogravimetric analysis (TGA) was employed to evaluate the thermal stability and degradation behaviour. In particular, nanocomposites exhibited an increase of 5–24 % in elastic modulus, aligning with predictions from analytical models. This research underscores the potential of PAN nanofibre mats for the development of lightweight, high-performance nanocomposites, offering a novel methodology for the enhancement of composite materials. [ABSTRACT FROM AUTHOR]

Aluminum composites, reinforced with CNT and ZrO2 particles, were synthesized via powder metallurgy, undergoing mechanical testing and molecular dynamics (MD) simulations. Hybrid reinforcement significantly increased strength and hardness while preserving toughness through extrinsic toughening mechanisms, preventing a substantial drop in energy absorption. MD simulations revealed dislocation nucleation at reinforcement interfaces, enhancing material strength during propagation. Various reinforcements activated specific strengthening mechanisms, quantified by models. The hybrid composite exhibited excellent strength enhancement and maintained toughness up to a specific reinforcement content. Despite a reduction in energy absorption, the remarkable strength improvement suggests synergistic reinforcement effects, suitable for high-performance, lightweight materials. [ABSTRACT FROM AUTHOR]

The reduced graphene oxide-Cu self-lubricating composites with short carbon fiber fillers were fabricated by powders wet-mixing combined with hot-pressed sintering process. The impacts of short carbon fiber content on microstructure, mechanical and tribological performance of reduced graphene oxide-Cu composites were characterized. The reduced graphene oxide/carbon fiber hybrid fillers were randomly distributed in the sintered bulk compacts. The hybrid filled composites achieved enhancement in mechanical and tribological properties. With increasing carbon fiber content, hardness and compressive yield strength of the prepared composites were increased, and both friction coefficient and wear rate showed a constant decrease trend under different loads. Owing to the synergy effect of reduced graphene oxide/carbon fiber hybrid lubricant fillers during sliding together with the greatly enhanced hardness and yield strength, up to 0.6 wt% carbon fiber incorporation resulted a lowest friction coefficient and decreased wear rate. Randomly distributed reduced graphene oxide/carbon fiber hybrid fillers provided the lubrication to reduce friction and wear for Cu matrix. [ABSTRACT FROM AUTHOR]

Microbial fuel cell (MFC) has been regarded as a promising green and clean electricity generation device. The anode plays a crucial role in the electricity generation process within the MFC. This study employed a hydrothermal method for the doping of sulfur onto MXene nanosheets to alleviate the stacking, followed by an in situ polymerization process to fabricate sufur-doped MXene/polypyrrole (S–MXene/PPy) composite hydrogel on carbon felt (CF). The MFC constructed with this anode exhibited the highest power density of 8.05 W m−3 and a maximum output voltage of 646 mV, higher than that of MXene/PPy (623 mV, 6.03 W m−3), PPy (594 mV, 4.91 W m−3), and unmodified CF (574 mV, 4.05 W m−3). This improved performance can be attributed to the reduction of charge transfer resistance in the material while improving the bacteria affinity, leading to enhanced extracellular electron transfer (EET) efficiency. High-throughput sequencing indicates that the excellent biocompatibility significantly promotes the attachment and growth of electroactive microorganisms (Geobacter, 45.34%) on the S–MXene/PPy anode. This study demonstrates that S–MXene/PPy hydrogel has good potential as an anode from the perspective of MFC electricity generation and microbial analysis. [ABSTRACT FROM AUTHOR]

In this study, α- and β-MnO2 and composites with carbon black (CB) were chemically synthesized and prepared through mechanical mixing respectively. The samples' crystal structure, morphology, and electrical properties have been investigated herein. It is found that average particle sizes of 12–15 nm and 18–24 nm for α- and β-MnO2, respectively. The surface area and average pore volume of obtained samples of α- and β-MnO2 are 200 and 70 m2/g, and 3.2 and 5.3 nm, respectively. The electrical conductivity performances and activation energy behavior of samples have been analyzed. The correlation between the CB content in the composites and their electrical conductivity was established based on experimental data. The electrical conductivity of the α-MnO2/C monotonic increase from 1.31 to 18.6 S/m. There was a 7.5-fold increase of conductivity for α-MnO2 with 15 wt.% CB and almost a 30-fold increase for β-MnO2 with the corresponding CB content compared to the pure samples. In composite samples, the activation energy decreases from 0.069 to 0.041 eV and from 0.154 to 0.074 eV for α- and β- MnO2/C, respectively. [ABSTRACT FROM AUTHOR]

In this study, SnO wrap on SnS was prepared and incorporated into carbon fiber/expanded graphite (CF/EG) cementitious composites by the coating process. The effects of different SnO wrap on SnS coating ratios and contents on the microstructures of CF/EG cementitious composites were investigated and discussed, and the thermoelectric properties of SnO wrap on SnS CF/EG cementitious composites were systematically investigated in the temperature range of 35–70 °C. The results show that the coating ratio and content of SnO wrap on SnS have a significant effect on the thermoelectric properties of CF/EG cementitious composites. It is noteworthy that when the SnO wrap on SnS is 2:1, the thermoelectric properties of its cementitious composites are greatly improved. For example, when it is added at 1.0 wt%, the conductivity is 2.27 S/cm, the Seebeck coefficient is 41.90 µV/°C and the power factor is 0.38 µW·m−1K−2. The addition of SnO wrap on SnS to CF/EG cementitious materials generates a large number of interfaces, and the presence of high-density interfaces hinders the motion of carriers, which leads to the scattering of carriers at the interfaces and enhances the Seebeck effect in cementitious composites. Therefore, SnO wrap on SnS has great potential for thermoelectric applications. [ABSTRACT FROM AUTHOR]

Aluminium-carbon nanotube (Al-CNT) composites have proven to offer a lot of potential for applications involving friction and wear. This study investigated the wear behaviour of Al-CNT composites with uniformly dispersed CNTs without structural damage at concentrations of 0.5 wt%. The wear behaviour of these composites has been compared with that of pure aluminium, which was fabricated using the identical wet shake mixing, compaction, and extrusion procedure. The study aimed to determine how CNT concentration and applied stress influence the wear behaviour of composite materials. Scanning electron microscope (SEM) was used by the researchers to examine the surface features of the worn samples. The study showed a significant increase in hardness and wear resistance with adding CNT. Compared to pure aluminium, the composite containing 0.5 wt. % CNTs demonstrated a 25% reduction in wear rate, and the average value of the coefficient of friction (µ) also decreased. The wear rate and coefficient of friction increased when samples containing 0.5 wt. % CNTs were subjected to various loading scenarios. The major contribution of CNTs to improving wear characteristics was discovered through SEM investigation of these worn surfaces. Using the ANSYS Workbench, a built finite element model was used to perform contact analysis on the disc and pin. Analytical results and experimental data were contrasted, and the ANSYS data was utilised to assess the process parameters. The comparison confirmed the analysis accuracy and dependability, which showed a consistent agreement between the analytical findings and the experimental results. [ABSTRACT FROM AUTHOR]

In evaluating high-performance multiwall carbon nanotube (MWCNT) based carbon fiber composites, effective chemical functionalization of fillers for sufficient exfoliation and precise interface interactions with resin matrix are challenging to attain due to significant interlayer cohesive energy and inactive surfaces of composites. Herein, we demonstrate an effective way to produce carbon fiber-reinforced polymer (CFRP) composite with amended interfacial characteristics via incorporation of MWCNT through oxidation followed by silane functionalization with their exfoliation levels (0/48/60/72 h). The surface functional elements, morphological changes, elemental groups, quantitative information, and thermal degradation of silane functionalized MWCNTs were characterized by FESEM/HR-TEM, XRD, UV, and TG-DTA analysis, respectively. The influence of silane functionalized MWCNT reinforcement on CFRP's mechanical properties were examined using tensile, flexural, ILSS, and damping behavior was analyzed through impulse excitation technique (IET). The resulting silane-modified MWCNTs with 60 h oxidation (OAC-60) infused CFRP demonstrated significant enhancement in flexural strength (73.8%), tensile strength (58.2%), interlaminar shear strength (28.5%) compared to pure-CFRP. [ABSTRACT FROM AUTHOR]

Fabricating non-noble metal-based carbon air electrodes with highly efficient bifunctionality is big challenge owing to the sluggish kinetics of oxygen reduction/evolution reaction (ORR/OER). The efficient cathode catalyst is urgently needed to further improve the performance of rechargeable zinc-air batteries. Herein, an activation-doping assisted interface modification strategy is demonstrated based on freestanding integrated carbon composite (CoNiLDH@NPC) composed of wood-based N and P doped active carbon (NPC) and CoNi layer double hydroxides (CoNiLDH). In the light of its large specific surface area and unique defective structure, CoNiLDH@NPC with strong interfacecoupling effect in 2D-3D micro-nanostructure exhibits outstanding bifunctionality. Such carbon composites show half-wave potential of 0.85 V for ORR, overpotential of 320 mV with current density of 10 mA cm-2 for OER, and ultra-low gap of 0.70 V. Furthermore, highly-ordered open channels of wood provide enormous space to form abundant triple-phase boundary for accelerating the catalytic process. Consequently, zinc-air batteries using CoNiLDH@NPC show high power density (aqueous: 263 mW cm-2, quasi-solid-state: 65.8 mW cm-2) and long-term stability (aqueous: 500 h, quasi-solid-state: 120 h). This integrated protocol opens a new avenue for the rational design of efficient freestanding air electrode from biomass resources. [ABSTRACT FROM AUTHOR]

In this research work, an attempt was made to reinforce AA7050/5Gr composites with multi-walled carbon nanotube (MWCNT) of varying weight percentages processed through stir casting route. SEM with EDS mapping revealed that the particles were uniformly distributed over the composites. Hardness reduces with increasing MWCNT weight percentage owing to the inverse hall petch effect and increment in void content. A third-body abrasion, which happens when the CNT in the aluminium matrix material detaches from the surface and erodes material from the composites pin as well as the counter face, causes the wear resistance to rise with the addition of CNT particles. A mechanically mixed layer, which avoids direct metal-to-metal contact and thus increases wear resistance, was created at the abraded surface and at high temperature, where the reduction of wear rate was due to the development of oxide protective layer. A steady-state wear equation for the contacting surface at high temperature (R = 1/Y √(ln W/2X)) for AA7050 hybrid composites–steel interface was developed. The enhancement in wear resistance was directly proportional to the proportion of ferrous content present on the surface, which was confirmed on the elemental analysis. Pock marks, micropits, craters and cracks were the features observed on the worn surface morphology, whereas delamination and plasticisation were the observed modes of wear mechanism. [ABSTRACT FROM AUTHOR]

Inspired by physical field freezing technology from frozen food engineering, the ultrasonic field and static magnetic field are integrated simultaneously into the freeze‐drying process to prepare aerogel for the first time. Taking polyimide(PI)‐derived carbon composite aerogels as an example, it is demonstrated that the ultrasonic field and magnetic field are capable of regulating the ice crystal size by affecting the liquid cooling phase and the phase transition phase, respectively. The aerogel structure with small pore size and narrow pore size distribution is obtained. Thus leading to the formation of an abundant conductive network and heterogeneous interface, so as to realize the regulation of the porous structure of aerogels. Secondly, the coupling of ultrasound and magnetic fields addresses the agglomeration and realizes the orientation alignment of nanofillers. The charge storage capacity and conductivity of the system are improved. Therefore, the electrical conductivity, conductive loss, polarization loss, and multiple reflections of the composite aerogel are enhanced to obtain improved electromagnetic shielding performance microwave absorption property. The present work provides a scalable reactive processing pathway for the structural modulation of aerogels. [ABSTRACT FROM AUTHOR]

A new thermal insulation microactuator for Braille display using a phase change material (PCM) composite with induction heating is proposed. The PCM composite is prepared by fully mixing paraffin with multi-walled carbon nanotubes (MWCNTs), which is mainly used as both electrically and thermally conductive enhancer. As a result of that, the PCM composite is conductive and a wireless induction heating can be realized with the paraffin composite, which avoids the connection of wires from the inner chamber with a relatively simple fabrication process. In order to prevent the penetration of the paraffin from the elastic film, a solvent-resistant TPU diaphragm is adopted to seal the PCM chamber. In addition, thermal insulation between the higher temperature of PCM and the finger contact is designed by adding the PDMS diaphragm with PDMS pins. When the input power is 1.29W at AC frequency of 1kHz, the actuation height of the Braille dot reaches 259μm within 7s. The microactuator for Braille display presented in this paper has the advantages of short response time, thermal isolation, simple fabrication, small size and low cost. [ABSTRACT FROM AUTHOR]

Highlights In this paper, a mortise‐and‐tenon structural design was introduced into composite maintenance to create a new type of joint between the repair patches and the parent structure, where both the patches and the structure were carbon fiber composites. Effects of different joints, including step‐lap and mortise‐and‐tenon‐lap joints, on the bending failure of the repaired composites were simulated and then verified through experiments. Results showed that compared with the traditional step‐lap method, the mortise‐and‐tenon connection changed the direction of damage extension from a simple single path to complex multiple paths, which effectively inhibited the damage expansion and enhanced the structural damage tolerance. Therefore, the flexural strength of the repair with the new joint was improved by 19.9%. However, the mortise‐and‐tenon‐lap joint resulted in a poor moisture‐heat resistance of the repaired structure. Interestingly, although the flexural strength of the mortise‐and‐tenon repair decreased by 10.45% after the hygrothermal treatment, it was still higher than that of the step‐lap repair without hygrothermal treatment. A novel joint, mortise‐and‐tenon, was introduced into composite maintenance. Damage extended along multiple paths in the new joint and was inhibited. Flexural strength of the repair was higher than that of traditional step‐lap repair. [ABSTRACT FROM AUTHOR]

In order to prepare low-cost and heat-resistant poly(lactic acid) (PLA) composites, in this study, bamboo fiber (BF) was added to stereo-complex crystal PLA (SC-PLA) to prepare heat-resistant composites. Poly[(phenyl isocyanate)- co -formaldehyde] [a polyaryl polymethylene isocyanate (PAPI)] was used to form cross-linked structures between SC-PLA and BF, and the effects of PAPI-cross-linked structures on the crystallization properties, mechanical properties, and heat resistance of BF/SC-PLA composites with different BF contents were systematically investigated. When 15% BF was added, the mechanical properties of the composite were significantly improved. The tensile strength increased by 85.5% compared to the unmodified composite, reaching 34.7 MPa, which was even higher than that of the SC-PLA composite (33.1 MPa). In addition, in order to explore the impact of the PAPI-modified BF/SC-PLA composite on the environment and carbon emissions, a life cycle assessment (LCA) of the composites was conducted. The addition of BF effectively reduced the impact of the composite on the environment. Notably, the emissions of CO2 decreased by approximately 11.7%, and the freshwater, marine, and land ecotoxicity were also significantly reduced. This work provided a reference for the preparation of low-cost and heat-resistant PLA composites for heat-resistant food packaging and disposable tableware and expanded the application of PLA products in the field of heat-resistant materials. [ABSTRACT FROM AUTHOR]

The direct coupling of nitrate ions and carbon dioxide for urea synthesis presents an appealing alternative to the Bosch–Meiser process in industry. The simultaneous activation of carbon dioxide and nitrate, however, as well as efficient C−N coupling on single active site, poses significant challenges. Here, we propose a novel metal/hydroxide heterostructure strategy based on synthesizing an Ag−CuNi(OH)2 composite to cascade carbon dioxide and nitrate reduction reactions for urea electrosynthesis. The strongly coupled metal/hydroxide heterostructure interface integrates two distinct sites for carbon dioxide and nitrate activation, and facilitates the coupling of *CO (on silver, where * denotes an active site) and *NH2 (on hydroxide) for urea formation. Moreover, the strongly coupled interface optimizes the water splitting process and facilitates the supply of active hydrogen atoms, thereby expediting the deoxyreduction processes essential for urea formation. Consequently, our Ag−CuNi(OH)2 composite delivers a high urea yield rate of 25.6 mmol gcat.−1 h−1 and high urea Faradaic efficiency of 46.1 %, as well as excellent cycling stability. This work provides new insights into the design of dual‐site catalysts for C−N coupling, considering their role on the interface. [ABSTRACT FROM AUTHOR]

The use of a highly efficient and noble-metal-free cocatalyst, which is being pursued to create hydrogen (H 2) via photocatalysis, has been the subject of many studies. In this work, a unique ultrasonication-assisted laser beam irradiation process is employed to synthesize a new carbon material generated from pineapple peel biowaste (ppC) and mix it with oxygen-deficient black zinc oxide (b-ZnO vac) nanoparticles. In the ppC x @b-ZnO vac nanostructures, the XPS analysis verified the presence of surface oxygen (O 2) defects and vacancies as well as chemical interactions between carbon and zinc via carbon-zinc (C–Zn) and carbon-oxygen-zinc (C–O–Zn) connection interfaces. Following optimization, the visible light active photocatalytic H 2 production rate of the ppC 10 @b-ZnO vac nanostructures reached 215.92 μmol h−1 g−1, which was the highest. The positive synergistic interaction between b-ZnO vac and ppC is responsible for the significant increase in the rate of H 2 generation. Furthermore, the significant chemical bond between ppC and b-ZnO vac via the C–Zn/C–O–Zn interface, as well as the development of surface O 2 vacancy defects in b-ZnO vac , improve the efficient transfer of energetic electrons and make visible active photocatalytic H 2 production from methanol in the ppC x @b-ZnO vac nanostructures easier. Our work presents a new strategy for chemically generating affordable carbon materials through the use of metal oxide-based photocatalysts with surface O 2 vacancy defects and bio-waste. Applications such as water splitting, energy production, and environmental remediation show promise for these advanced materials for large-scale field applications. [Display omitted] • ppC x @b-ZnO vac were prepared by ultrasonication-assisted laser beam irradiation. • ppC 10 @b-ZnO vac exhibit the highest H 2 production at 215.92 μmol h−1 g−1. • Synergistic effect and surface O 2 vacancies defect enhances H 2 production. • Effective electron transfer between ppC and b-ZnO vac via C–Zn@C–O–Zn interface. [ABSTRACT FROM AUTHOR]

Sn and C nanocomposites are ideal anode materials for high‐energy and high‐power density lithium ion batteries. However, their facile and controllable synthesis for practical applications is still a critical challenge. In this work, a facile one‐step method is developed to controllably synthesize ultrafine Sn nanocrystals (< 5 nm) loaded on carbon black (Sn@C) through Na reducing SnCl4 by mechanical milling. Different from traditional up‐down mechanical milling method, this method utilizes mechanical milling to trigger bottom‐up reduction reaction of SnCl4. The in‐situ formed Sn nanocrystals directly grow on carbon black, which results in the homogeneous composite and the size control of Sn nanocrystals. The obtained Sn@C electrode is revealed to possesses large lithium diffusion coefficient, low lithiation energy barrier and stable electrochemical property during cycle, thus showing excellent lithium storage performance with a high reversible capacity (942 mAh g−1 at a current density of 100 mA g−1), distinguished rate ability (480 mAh g−1 at 8000 mA g−1) and superb cycling performance (730 mAh g−1 at 1000 mA g−1 even after 1000 cycles). [ABSTRACT FROM AUTHOR]

Highlights Carbon fiber reinforced polymer (CFRP) is a high‐performance composite material composed of carbon fibers embedded in a polymer matrix. CFRP is extensively used in various sectors such as aerospace, automotive, sports equipment, and construction due to its advantageous properties. Laser processing offers numerous advantages when working with carbon fiber‐reinforced composites, including its non‐contact nature, precision, efficiency, and controllability. However, disparities between carbon fibers and the polymer matrix can lead to challenges during laser processing, such as delamination, heat‐affected zones, and fiber pullout. Consequently, there is a substantial body of literature focusing on improving the quality and efficiency of laser processing for CFRP materials. This paper provides a comprehensive review of various studies investigating the impact of laser parameters (laser mode, pulse frequency, pulse width, and laser wavelength) on carbon fiber‐reinforced plastics. It discusses how different laser parameters affect the processing quality and performance of these materials. Additionally, drawing from recent research findings, the paper explores potential future trends in laser processing for carbon fiber‐reinforced plastics. The application of laser technology in CFRP, including laser cutting, drilling, welding, and surface treatment, has been extensively researched. A detailed discussion is held regarding the impact of laser mode, wavelength, frequency, and pulse width on the quality of machining. More auxiliary processing has evolved in CFRP manufacturing due to the ongoing advancements in laser technology. The goals of laser processing CFRP technology are increasingly focused on reducing carbon emissions, enhancing energy efficiency, and minimizing waste. [ABSTRACT FROM AUTHOR]

Endowing transition metal dichalcogenides (TMDs) with mesoporous structure can greatly enhance their porosity, accessible specific surface area, and exposed active sites, leading to better performances in applications based on interfacial reactions. Current methods including hard‐template (nanocasting) method or thermal‐assisted conversion (TAC) still suffer from drawbacks such as cumbersome and environmentally unfriendly process, humidity sensitivity, or ill‐defined mesostructures. Herein, the study reports a facile synthesis of ordered mesoporous TMDs/carbon composites by direct organic–inorganic co‐assembly in dual solvent (DMF/H2O). The amphiphilic block copolymer polyethylene oxide‐b‐polystyrene (PEO‐b‐PS) is used as the organic template, and (NH4)2MoS4 or (NH4)2WS4 as the inorganic precursor. After solvent evaporation‐induced aggregation assembly and thermal treatments, it results in highly ordered mesoporous MoS2, WS2, and MoS2/WS2 with highly crystalline framework, high specific surface area (44‐91 m2 g−1) and large pore sizes (15–21 nm). Semiconductor gas sensors based on mesoporous TMDs exhibit extraordinary sensing performances toward NO2 at room temperature, including high sensitivity and ultrahigh selectivity, benefiting from its abundant adsorption sites for gas molecules, fast diffusion rate in well‐connected mesopores, and rich edge active sites. This work paves a facile way to develop novel ordered mesoporous TMDs‐based semiconductor materials for various applications. [ABSTRACT FROM AUTHOR]

Highlights Research on the performance design and prediction method of low carbon degradable composite materials is of great significance for realizing energy saving and emission reduction of automobile industry. In this study, plant short fiber reinforced polylactic acid composite (PFRP) was prepared by injection molding method and reinforced with basalt fiber to obtain flax/basalt short fiber hybrid reinforced composite (FBFRP). The mechanical properties of the composites were evaluated by quasi‐static tensile/ bending test and scanning electron microscopy (SEM). It was observed that addition of basalt fiber further enhances the properties of the composite, and the properties of the composite are the best when the mass fraction of flax and basalt fiber is 30% and 9%. The fiber distribution inside FBFRP was analyzed by micro‐computed tomography (Micro‐CT) technology. Based on the real spatial characteristics of the fibers inside the materials, a microcosmic representative volume element (RVE) model of hybrid composites was established by writing a random adsorption algorithm script in Python. By defining the damage constitutive of each component, the macroscopic equivalent mechanical property parameters were obtained, and the influence of the interface thickness on the simulation results was studied. On this basis, the tensile and bending failure simulation of macro‐composite materials is carried out, and the mechanical properties prediction of hybrid fiber composites based on multi‐scale method is successfully realized. Using Micro‐CT technique and random adsorption algorithm, the RVE model based on the real fiber distribution inside the composite was obtained. Through cross‐scale simulation, the macroscopic equivalent mechanical properties of the composite were obtained. The effect of fiber‐matrix interface thickness on the simulation results is considered. [ABSTRACT FROM AUTHOR]

Highlights The use of polyacrylic acid‐polypropylene‐polyacrylic acid triblock copolymers (PAA‐iPP‐PAA, abbreviated as iPP‐PAA) with different acrylic acid contents (9, 19.5, 29 wt%) as compatibilizers for carbon fiber (CF)/polypropylene (PP) composites and their effect on the tensile properties of the composites were investigated. The addition of iPP‐PAA improved the tensile properties of the CF/PP composites. This enhancement in mechanical properties was considered to be due to the hydrogen bonding network between iPP‐PAAs, which improved the mechanical properties of the matrix resin itself, and to hydrogen bonding between carbon fiber surface and iPP‐PAAs, which improved the interfacial adhesion. A higher acrylic acid content of iPP‐PAA resulted in better interfacial properties; however, excessive acrylic acid content adversely affected the crystallinity and tensile properties of the composite, which suggests that there is an optimum acrylic acid content for the iPP‐PAA. The results indicated that iPP‐PAA is an effective compatibilizer in CF/PP composites, and the iPP‐PAA with the best performance had an acrylic acid content of 19.5%. PAA‐PP‐PAA copolymers used as compatibilizers for CF/PP composites. Acrylic acid content of PAA‐PP‐PAA varied as 9%, 19.5%, and 29%. Tensile properties of CF/PP composites enhanced by iPP‐PAA addition. Hydrogen bonding improved mechanical properties of matrix resin and CF‐resin adhesion. Optimum acrylic acid content for CF/PP composite was 19.5%. [ABSTRACT FROM AUTHOR]

Highlights This research aims to investigate the low‐velocity impact (LVI) response and self‐healing performance of carbon fiber composite laminates (NL) containing staggered hybrid polyamide nanofiber veils. Carbon fiber‐reinforced polymer (CFRP) composites are widely used in many industries, but they are sensitive to LVI damage and there is a lack of research on repair, which restricts their development. In the research, NL samples were prepared, and four impact energies of 6.6, 9.4, 12.2, and 15.0 joules were selected. Ultrasonic C‐scan detection, microscopic observation and mechanical property tests were carried out. The results show that the NL samples have smaller damage areas and degrees, indicating that the veils enhance the impact resistance; the damage repair efficiencies of the NL samples at different energies are 48.3%, 36.2%, 29.7% and 16.8% respectively; when the impact energy is lower than 13.9 J, the flexural strength of the repaired NL samples can be restored to more than 80% of the original strength. These results are of great significance. The improvement of the impact resistance of composites by hybrid polyamide nanofibers can solve the problem of CFRP's sensitivity to LVI damage, and the self‐healing ability provides a new approach to damage treatment, having broad application prospects in aerospace, shipbuilding and other industries. Hybrid veils enhance impact toughness, reducing damage area and severity. Veils enable self‐healing, repair impact damage, and enhance reusability. Repair efficiency is higher at lower impact energy levels. [ABSTRACT FROM AUTHOR]

Due to the advancement of industrialization, water pollution has become an alarming global issue. Many organic dyes, such as crystal violet and rhodamine B, present in industrial wastewater are causing severe health problems. Both of these dyes are carcinogenic. For their degradation, ferrites are synthesized in this research. Ferrites have high absorbing potential in visible regions and fast movement of charge carrier species. Therefore, the ferrites are potentially used in photocatalysis to purify contaminated water. Graphitic carbon nitride shows enhanced separation of charges, which lowers the rate of recombination of charge carrier species. Lithium nickel ferrite, lithium nickel ferrite doped with terbium, and its composite with graphitic carbon nitride (g-C 3 N 4) are synthesized by sol-gel and ultra-sonication methods, respectively. The prepared samples are analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis. The bandgap of LiNiFe 2 O 4 and LiNiTbFe 2 O 4 was 2.35 eV, and 1.87 eV, respectively. LiNiTbFe 2 O 4 @g-C 3 N 4 degraded 86 % crystal violet and 83 % rhodamine B in 120 min. The LiNiTbFe 2 O 4 @g-C 3 N 4 composite showed the maximum degradation and can be potentially used in wastewater treatment. [ABSTRACT FROM AUTHOR]

Recently, SiC-continued fiber-reinforced ceramic matrix composites were widely used in high-temperature absorbing materials. However, the excessive carbon content indicated the deteriorative absorbing property. To solve the impedance mismatching of the SiC matrix and increase the charge accumulation at the multi-phase interface, SiCf/mullite composites were prepared in this paper by using the sol–gel method. The introduction of mullite matrix without free carbon improved impedance matching characteristics. The strong bonding between the in situ grown SiO2 layer and the mullite matrix caused by high temperature induced the Maxwell–Wagner effect, which effectively optimized the absorbing performance. The complex dielectric constant of the composite increased with higher sintering temperatures. The highest reflection loss reached − 23.1 dB at the sintering temperature of 1100 °C. With the two-step drying process, the porosity was reduced to 16.1% and the density increased. The crystallinity and density of the mullite matrix increased in the rising sintering temperatures, with the highest bending strength reaching 157.89 MPa for composites sintered at 1100 °C. [ABSTRACT FROM AUTHOR]

Luminescent materials with time‐resolved dynamic discoloring afterglow (TDDA) hold significant potential for applications in anti‐counterfeiting and data encryption. However, the afterglows coming from organic systems are usually unidentifiable due to their shorter durations (less than 10 s). Achievement of long‐lasting and visually discernible TDDA remains highly desirable but challenging. In this work, the TDDA duration is successfully extended from less than 10 s to minutes by engineering the luminescent centers of carbon dots (CDs) and introducing deep trap‐states in a composite of CDs and carbon nitrides (CNs) (named Y‐CDs@CN). It is confirmed that the regulation of luminescent centers in CDs containing both C═N and C═O bonds is responsible for the color changes during TDDA from yellow to green. Moreover, the generation of deep trap states is found to be significant for prolonging the afterglow duration to minutes level through converting room temperature phosphorescence into long persistent luminescence, thus making the entire dynamic discoloring process being easily recognized to naked eyes. Furthermore, the afterglow of Y‐CDs@CN can also be excited by blue light and even using white light of a cell phone. To harness these characteristics, potential applications of Y‐CDs@CN for portable anti‐counterfeiting and multidimensional information encryption are primarily investigated. [ABSTRACT FROM AUTHOR]

Biomass and its derived carbon materials, due to their glorious application value in the field of microwave absorption, have sparked a new round of research boom. Hereinto, platan seeds-derived carbon-based materials (PSC), offspring from direct carbonization of platan seeds, were ulteriorly processed and subjected to high-temperature carbonization treatment to synthesis PSC/Ni/Co composite with diversified morphology and tunable microwave absorption performance. The effect of nickel and cobalt ion concentrations on the absorption performance of composite materials was investigated in depth. The optimum reflection loss value (RLmin) of PSC/Ni can reach −47.36 dB, while its effective absorption broadband (EAB) is 5.8 GHz, ranging from 12–17.8 GHz, covering almost the whole Ku band. Compared with PSC/Ni composites, PSC/Co fulfils greater advantages in thickness and bandwidth. As for PSC/Ni/Co, the sample exhibits the optimal performance when Ni and Co ions are at equal concentrations, with an RLmin of −48.3 dB and an EAB of 5 GHz (13–18 GHz), which congealed the edges of both. Unequivocally, the morphological polymorphism of carbon-based-derived microwave absorbing materials with platan seeds as the carbon source is crucial to harvset lightweight, efficient and adjustable absorption properties, let alone its relatively simple and feasible preparation method. This may provide a new approach for engineering light-weight, cost effective and eco-friendly absorbing materials. [ABSTRACT FROM AUTHOR]

Highlights Digital Light Processing (DLP) techniques are being increasingly investigated to create advanced composite materials with improved properties by incorporating a variety of nanoparticles. In this study, the mechanical and electrical properties of photopolymer nanocomposite materials reinforced with carbon‐based nanoparticles produced by DLP were investigated. The nanocomposites were produced by incorporating varying proportions of Multi‐Walled Carbon Nanotubes (MWCNT), reduced Graphene Oxide (rGO), and combinations of Carbon Black and Carbon Nanotubes (CB/CNT) into the photopolymer matrix. The mechanical properties of the nanocomposites were assessed by tensile testing, while their electrical conductivity was determined using the four‐point probe technique. This study was the first to investigate the most effective concentrations of three distinct carbon‐based nanoparticles and the impact of their homogeneous distribution on the performance of composites with a holistic approach. The morphological analysis of the composites, conducted using optical microscopy and Scanning Electron Microscopy (SEM), revealed the critical role of nanoparticle distribution in determining composite properties. The findings indicate that the incorporation of nanoparticles at low proportions (up to 0.5 wt%) resulted in a significant improvement, with up to an 82% increase in the ultimate tensile strength of the photopolymer. Nevertheless, as the nanoparticle ratio increased, a rise in material brittleness and a decrease in mechanical strength were observed. On the other hand, electrical conductivity showed a significant increase when the percolation threshold was exceeded in the composites reinforced with MWCNT (0.5%wt) and CB/CNT (0.75%wt). The properties of DLP composites with carbon nanoparticles are investigated. SEM analysis shows nanoparticle dispersion's key role in composite performance. 0.5% rGO reinforcement boosts tensile strength by up to 82%. Conductivity surges at 0.5% MWCNT, surpassing the percolation threshold. High nanoparticle ratios increase composite brittleness. [ABSTRACT FROM AUTHOR]

As typical dielectric materials, transition metal compounds have a broad potential in the field of stealth, but their application is still hampered by poor conductivity. In this study, based on the mechanism of electrostatic self-assembly of heteropolyacids and organic ligands, the electrostatic structures obtained after the introduction of different heteropolyacids into the conductive phase pyrrole are carbonized. On the one hand, the as-prepared transition metal compounds/carbon matrix nanocomposites produce synergistic effects and optimize impedance matching, and on the other hand, the formation of the abundant heterogeneous interfaces as well as the doping of the N, P heteroatoms induce the generation of interfacial polarisation and dipole polarisation, all of which provide the opportunities to produce composites with enhanced electromagnetic wave absorption properties. Unsurprisingly, the best synthesised sample, Mo 2 C/W 2 C/NPC, exhibits a significantly improved electromagnetic wave absorption performance, with an effective bandwidth of 5.7 GHz at a matched thickness of 2.5 mm, where the minimum reflection loss value of −54.5 dB is also achieved. The total effective bandwidth of the Mo 2 C/W 2 C/NPC-35 wt% is up to 10.5 GHz (7.3–17.8 GHz) via adjusting the matching thickness in the range of 1.7–3.5 mm. Therefore, this study reflects that dual transition metal compound/carbon based composite wave-absorbing materials provide a new material basis for the construction of high-performance absorption materials. [ABSTRACT FROM AUTHOR]

Multicomponent solid solution ceramics have attracted extensive attention for their superior ablation resistance and high-temperature resistance, which are expected to extend the service life of carbon/carbon (C/C) composites under an ablation environment above 2000 °C. Herein, we synthesized (Hf ⅓ Zr ⅓ Ta ⅓)C solid solution ceramic powders via carbothermal reduction. Then a dense (Hf ⅓ Zr ⅓ Ta ⅓)C solid solution ceramic coating was deposited on SiC-coated C/C composites by supersonic atmospheric plasma spraying. The coated samples exhibited a low linear ablation rate of −0.61 μm/s after ablation for 120 s, mainly associated with the formation of a compact oxide scale consisting of (Hf, Zr) 6 Ta 2 O 17 and (Hf, Zr)O 2. The refractory (Hf, Zr)O 2 skeleton structure possessed good thermal endurance, and the Ta-rich oxide melt filled the defects of the skeleton. [ABSTRACT FROM AUTHOR]

An addition of carbon nanostructures to cement paste is problematic due to the difficulties in obtaining homogenous mixtures. The paper reports on a more effective way of mixing carboxylated multi-walled carbon nanotubes (MWCNT-COOH) in cement pastes. The additional biological impact of the studied nanomodified cement was analyzed in the case of two moss species' vitality. The applied approach of obtaining a homogeneous mixture is based on intense mechanochemical mixing of MWCNT-COOH together with polycarboxylate superplasticizer (SP). As a result, a more homogenous suspension of MWCNT-COOH within a liquid superplasticizer, suitable for addition to hydrophilic cement paste, was obtained. FT-IR/Raman spectroscopy was used for materials' characterization. To explain the mixing process at the molecular level, systematic theoretical studies using density functional theory (DFT) were performed. The structures, interaction energies and IR/Raman vibrational spectra of model carboxylic acids, mixed with functionalized SWCNTs as simplified models of real MWCNTs, were obtained. Due to the controversial opinions on the environmental hazards of carbon nanostructures, additional in vivo studies were performed. In this case, effects of cement modified by the addition of small amounts of MWCNT-COOH with SP in comparison to the composite without carbon nanostructures and control subsoil on the vitality of mosses Polytrichum formosum and Pseudoscleropodium purum were studied. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) exhibit high theoretical specific capacities, abundant resource reserves, and low costs, making them promising candidates for next-generation lithium-ion batteries (LIBs). However, significant challenges, such as the shuttle effect and volume expansion, hinder their practical applications. To address these issues, this study introduces a unique intermediate layer comprising N-doped carbon nanofiber/TiO2/diatomite (NCNF/TiO2/DE) from the perspective of membrane modification. The intermediate layer comprises nitrogen-doped titanium dioxide/carbon nanofiber (NCNF/TiO2) materials, with diatomite filling the fiber gaps. This forms a three-dimensional (3D) conductive network that provides ample space for sulfur volume expansion and numerous adsorption active sites, thereby accelerating electrolyte penetration and lithium-ion diffusion. These features collectively contribute to the outstanding electrochemical performance of the battery. At 0.1 C, the NCNF/TiO2/DE-800-coated separator battery achieved a first-cycle discharge specific capacity of 1311.1 mAh g−1, significantly higher than the uncoated lithium–sulfur battery (919.6 mAh g−1). Under varying current densities, the NCNF/TiO2/DE-800 material demonstrates good electrochemical reversibility and exhibits high lithium-ion diffusion rates and low charge-transfer resistance. Therefore, this study provides an advanced intermediate layer material that enhances the electrochemical performance of lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

With the widespread application of highly integrated electronic devices, the urgent development of multifunctional polymer‐based composite materials with high electromagnetic interference shielding effectiveness (EMI SE) and thermal conductivity capabilities is critically essential. Herein, a graphene/carbon felt/polyimide (GCF/PI) composite is prepared through constructing 3D van der Waals heterostructure by heating carbon felt and graphene at high temperature. The GCF‐3/PI composite exhibits the highest through‐plane thermal conductivity with 1.31 W·m−1·K−1, when the content of carbon felt and graphene is 14.1 and 1.4 wt.%, respectively. The GCF‐3/PI composite material achieves a thermal conductivity that surpasses pure PI by 4.9 times. Additionally, GCF‐3/PI composite shows an outstanding EMI SE of 69.4 dB compared to 33.1 dB for CF/PI at 12 GHz. The 3D van der Waals heterostructure constructed by carbon felt and graphene sheets is conducive to the formation of continuous networks, providing fast channels for the transmission of phonons and carriers. This study provides a guidance on the impact of 3D van der Waals heterostructures on the thermal and EMI shielding properties of composites. [ABSTRACT FROM AUTHOR]

Porous carbon is considered a promising adsorbent for carbon capture and sequestration, and pore structure and surface activity must be optimized in order to achieve high capture capacity and recycling performance. In this study, terephthalic acid and sodium hydroxide were used as raw materials to prepare sodium carbonate based porous carbon and metal oxide composites at TPA:NaOH:X(X = MgO, CaO, MgO/CaO, Mg(NO3)2,C, and Al2O3) = 1:1:2 and 600 °C. The analysis results show that the material MgO/Na2CO3 has the best CO2 adsorption capacity, and the adsorption capacity is 10.56cm3/g at 0 °C and 1 bar. The material Al2O3/Na2CO3 has the best thermal stability, and the MgO/Na2CO3 shows good recycling performance in the five cycle test. The high‐temperature calcination process makes the mesoporous structure of the material form, which makes the carbon composites show good capture performance, and sodium carbonate based solid adsorbents have good development and application prospects as CO2 capture and separation materials. [ABSTRACT FROM AUTHOR]