The high theoretical capacity of transition metal-based compounds makes them promising candidates for lithium-ion battery (LIB) anodes. Among them, iron selenide (FeSe2) has attracted considerable interest because of its excellent electrical conductivity and superior lithium storage capacity. However, pristine FeSe2 suffers from rapid capacity fading and structural instability during repeated cycling. Thus, this study used a facile solvothermal method to synthesize a FeSe2@rGO composite with enhanced structural integrity and electrical conductivity. By incorporating reduced graphene oxide (rGO), the composite demonstrated improved charge transfer kinetics and mechanical robustness. Morphological and structural characterizations were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy analyses (XPS), which confirmed the successful formation of the composite and its uniform distribution. Electrochemical properties were evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge, long-term cycling, and electrochemical impedance spectroscopy. The optimized FeSe2@rGO electrode delivered a high reversible capacity of 971.95 mAhg-1 at 500 mAg-1 after 350 cycles. The underlying charge storage mechanism was investigated using scan rate-dependent CV, which revealed a dominant capacitivecontrolled contribution at higher scan rates. The study findings indicate that the FeSe2@rGO composite can serve as a high-performance anode material with excellent cycling stability and rate capability, providing a viable strategy for the development of advanced LIBs.

Multimodal composites have the potential to play a crucial role in the development of theranostic agents. Systems with optical and magnetic response can be applied in medicine for both imaging and therapy; however, combining magnetic and luminescent nanoparticles in one entity is challenging. Both the morphology and architecture of the composite, as well as the influence of the magnetic components and matrix on the light-emissive component, must be paid attention. In this study, we demonstrate a design of a composite with advantageous magnetic response and luminescence in green and red regions (excited at 405 and 580 nm, respectively), where biocompatible CaCO3 microspheres were loaded and decorated with luminescent carbon dots (CDs) and magnetite nanoparticles (MNPs). We showed the absence of CDs’ toxicity by the IC50 tests and demonstrated its localization in L1 and L4 stages of C. elegans embryogenesis. We determine the optimal parameters for composite formation to achieve their improved performance and structural stability. The composites were fabricated in several steps, including loading nanoparticles and layer-by-layer application of polyelectrolytes on top of CaCO3. We demonstrated the applicability of the prepared composite microspheres for flow cytometry and showed their potential as multiplexed visualization agents, emphasizing their potential use as promising theranostic agents.

In this study, an anode composite material was fabricated by embedding spherical carbon-coated nanosilicon (Si@C) into a layered carbon-coated silicon (L-Si/C) to enhance the capacity and stability of silicon-based lithium-ion batteries. The L-Si/C material was obtained by reacting CaSi2 through a CO₂-assisted carbonization process, followed by removal of the CaCO3 byproduct via HCl etching. Si@C particles, prepared using polydopamine as a carbon precursor, were uniformly embedded in the L-Si/C via ultrasonic treatment. The physical properties of the prepared anode composites were analyzed using HR-SEM, EDS, XRD, and BET. The electrochemical performances were investigated using 1 M LiPF6 in EC:DEC (1:1 vol%) with 10 wt% FEC as the electrolyte, through charge–discharge cycling, rate capability tests, electrochemical impedance spectroscopy (EIS), and differential capacity (dQ/dV) analysis. L-Si/C exhibited the best electrochemical performance under the thermal treatment condition of 720 °C and a CO2 flow rate of 100 sccm. In addition, the application of ultrasonic treatment improved structural stability and rate capability. Consequently, the S_L-Si/C + Si@C-2 exhibited a high initial discharge capacity of 2700.7 mAh/g at 0.1 C and a capacity of 617.4 mAh/g at a high rate of 6 C.

In this study, GNPs/FeCoNiCuAl particles synergistically reinforced aluminum matrix composites are developed by friction stir processing (FSP) to explore the effects of different GNPs contents (1, 3, and 5%) on the microstructure, mechanical performance, and wear resistance of the materials. The results show that the incorporation of GNPs affects the formation of the diffusion layer between the FeCoNiCuAl particles and the aluminum matrix. As the content of GNPs increases, the thickness and integrity of the diffusion layer between FeCoNiCuAl particles and aluminum matrix gradually decrease. In addition, the introduction of GNPs is beneficial in enhancing the proportion of high-angle grain boundaries in the composites, but the grain size of the specimen increases slightly to about 5.5 μm at a content of 5% GNPs. When the content of GNPs is 1%, the composites achieve the highest microhardness and the lowest specific wear rate (0.1459 × 10⁻⁶ mm3/ N·m), with the wear mechanism dominated by abrasive wear. Nonetheless, when the GNPs content in the composite increases to 5%, the thickness and integrity of the diffusion layer are minimal, causing the tensile strength of the composite to be reduced to 250 MPa, and the specific wear rate increased to 0.4244 × 10– 6 ( mm3/N·m), with the wear mechanism transformed to abrasive–adhesive mixed wear. This study demonstrates that the appropriate ratio of GNPs and FeCoNiCuAl particles can effectively enhance the mechanical and wear resistance properties of aluminum matrix composites, providing a theoretical basis for the design and development of high-performance aluminum matrix composites.

This work introduces a high-performance absorber based on a lightweight composite material of corn straw biochar and magnetic cobalt nickel zinc ferrite. A composite absorber of corn straw biochar with hierarchical pore structure and magnetic zinc cobalt nickel ferrite particles (Ni–Co–Zn ferrite/C) was prepared by a simple two-step approach of carbonization followed by in-situ growth method. The morphology, structure, function, and absorbing properties of the prepared samples were characterized, and RCS simulation was performed. The results show that the optimal reflection loss value of Ni–Co–Zn ferrite/C-2 reaches −38.04 dB when the layer thickness is 3.5 mm, and the effective absorption bandwidth is 4.32 GHz. The potential of Ni–Co–Zn ferrite/C-2 composite material in stealth applications is verified. It is mainly attributed to the excellent impedance matching performance caused by the multi-level pore structure and the strong polarization loss caused by the rich heterogeneous interface and active sites, which plays a key role in the attenuation of electromagnetic waves. This study provides a useful reference for the design of magnetic ferrite particles/metal oxides/biomass-derived carbon microwave absorbing materials with hierarchical porous structure characteristics.

Poor bonding occurs with resin due to surface inertness of carbon fiber (CF), so CF surfaces were often treated. In some common surface treatments, sizing was a simple and effective modification method. Polyurethane (PU) was used as the main component of sizing agents due to its similar structure to polyamide 6 (PA6). The CF/PA6 composites’ interfacial properties were improved using PU as a sizing agent. Meanwhile, in this paper, glycidol (GLD) was introduced into the PU emulsion so that the epoxy group reacted with the carboxyl group on the acidified CF. After testing, when the content of glycidyl in the sizing agent is 2%, the CF/PA6 composites showed an important improvement in tensile, impact, and flexural strengths, which increased by 49.4%, 94.6%, and 53.2%, respectively. In addition, the effect of modified WPU sizing agents with different GLD contents on the properties of CF/PA6 composites was investigated.

This study experimentally evaluated the flexural behavior of reinforced concrete (RC) beams incorporating a high-performance cementitious composite (VC) with 1.0 vol.% Vectran fibers. Three-point bending tests were conducted on a reference high-strength concrete beam (RCB) and two VC beams (VCB-1, VCB-2). Compared with RCB, the maximum load increased by +19.8% (VCB-1) and +9.0% (VCB-2), while the yield load rose by +18.9% and +16.0%, respectively. The ductility index (Δu/Δy) improved from 1.89 (RCB) to 5.22 (VCB-1), confirming the crack control effect based on multiple micro-cracking. The improved performance indicates not only enhanced flexural capacity and ductility but also suggests the potential for carbon-neutral structural design through material reduction and service-life extension enabled by the Vectran fiber-reinforced composite system.

본 연구에서는 셀루로오스 나노섬유(CNF) 첨가와 (3-아미노프로필)트라이에톡시실란(APTES)로 표면 처리한 CNF가 시멘트 모르타르 복합체에 미치는 영향을 분석하였다. 일반 시료, 비개질 CNF, APTES 개질 CNF, 그리고 APTES 용액만 첨가한 경우 등 네 가지 조건을 주요 변수로 하여 시험을 진행하였다. 최적 성능은 CNF 0.3 wt%와 APTES 3 vol% 처리 시 나타났으며, 이 조건에서 압축강도와 휨강도가 가장 높게 나타났다. SME, XRD, FT-IR 분석 결과, 처리된 CNF가 수화 생성물과 균일하게 분산되고 화학적으로 결합함을 확인할 수 있었다. 이러한 결과를 통해 ATPES 처리로 CNF의 보강 효과가 시멘트 복합체의 역학적 성능을 크게 향상시킴을 확인할 수 있었다. 따라서 CNF 0.3 wt%와 APTES 3 vol%의 혼입 비율이 시멘트 복합체의 기계적 성능을 향상시키는 가장 효과적인 최적 배합비로 확인되었다.

A hierarchical porous carbon/silicon composite material (CSCM) was prepared through KOH activation and acid leaching using coal gasification fine slag (CGFS) as the raw material. The KOH dosage, activation temperatures, and HCl acid amount were optimized. The obtained CSCMs showed higher pore volume in the range of 0.62–0.96 cm3/ g, and hierarchical porous structure with Vmicro./ Vmeso. ratio in the range of 1.54–3.31. The influence of Vmicro./ Vmeso. ratio of CSCM on CO2 adsorption at 0 °C was higher than that at 25 °C. Under higher specific area and pore volume, hierarchical pores with Vmicro./ Vmeso. ratio in the range of 2.81–2.91 were benefit for CO2 adsorption at 0 °C. The optimized CSCM demonstrated excellent CO2 adsorption capacities of 2.96 and 4.60 mmol/g at 25 and 0 °C, respectively. CO2 adsorption on CSCM was a heterogeneous physical process, and the cycle stability was excellent. Meanwhile, CSCM was mixed with Fe-based catalyst (Fe-K/CS) for CO2/ H2 catalysis. The hierarchical porous structure of CSCM improved the CO2 adsorption and H2 adsorption around the active sites, promoting CO2 conversion. The combination method of Fe-K and CSCM affected the distribution of CO2 hydrogenation products, and reasonable Vmicro./ Vmeso. ratio in CSCM effectively inhibited C–C chain growth, leading to higher olefins selectivity. The Fe-0.1K/CS-P catalyst achieved a CO2 conversion rate of 21.6% and a C2 =-C4 = selectivity of 47.7%. This study presented a promising approach for effectively utilizing CO2 and for the sustainable valorization of industrial solid waste.

CNT/epoxy composite film (CECF) was prepared and used to fabricate the interlayer stiffened and reinforced photothermal synergistic curing glass fiber-reinforced polymer (GFRP) composites, and the influence of the photothermal effects of CECF on compressive strength and failure mechanism of the composite was investigated. Compared to GFRP composite, the uniform and wide temperature distribution in the in-plane and thickness direction was exhibited due to the heat from the lattice vibrations induced by photothermal conversions of CECF, thereby facilitating the decomposition of the thermal initiator and the increase of the curing degree in the CECF/GFRP composite. The in-plane shear modulus and interlaminar shear strength (ILSS) of the CECF/GFRP composite were 12.2% and 13.7% higher than those of the GFRP composite, respectively, indicating the enhanced deformation resistance and interfacial adhesion of the interlayer region. The compressive strength of the CECF/GFRP composite was increased by 14.1% relative to the GFRP composite, which was ascribed to restricted kink-band and delayed delamination damage during the compression process of composite.

Phase change materials (PCM) with enhanced thermal conductivity and electromagnetic interference (EMI) shielding properties are vital for applications in electronic devices, energy storage, and aerospace. However, achieving a synergistic improvement in both thermal and EMI shielding performance remains a significant challenge. This study presents the development of phase change composites reinforced with 3D Ag foam and short carbon fibers (SCF) to address this challenge. Ag@SCF/ PCM composites were fabricated using a vacuum-assisted impregnation and curing process. Polyethylene glycol and epoxy resin formed the PCM matrix, while SCF and Ag foam created a dual-scale interpenetrating network to provide channels for phonon and electron transmission. The dual-scale network significantly improves thermal conductivity (2.24 W/m·K) and EMI shielding (69.7 dB), while maintaining latent heat storage (melting: 71.5 J/g, freezing: 68.7 J/g). These multifunctional properties make Ag@SCF/PCM composites promising candidates for applications requiring simultaneous thermal management and electromagnetic performance optimization.

Manganese dioxide, functioning as a cathode material for aqueous zinc-ion batteries (AZIBs), demonstrates a variety of benefits, such as elevated theoretical specific capacity, outstanding electrochemical performance, environmental compatibility, ample resource availability, and facile modification. These advantages make MnO2 one of the cathode materials that have attracted much attention for AZIBs. Nevertheless, manganese dioxide cathode in practical applications suffers from structural instability during the cycling process because of sluggish electrochemical kinetics and volume expansion, which hinder their large-scale application. Doping and compositing with conducting frameworks is an effective strategy for improving structural stability. Herein, homogeneously in situ growth of Yttrium-doped MnO2 nanorods on conductive reduced graphene oxide (Y-MnO2/rGO), were synthesized through a straightforward hydrothermal method. The Y-MnO2/rGO electrodes have an ultra-long cycle life of 179.2 mA h g− 1 after 2000 cycles at 1 A g− 1 without degradation. The excellent structural stability is attributed to the cooperative effect of yttrium doping and compositing with rGO, which is an effective approach to enhance the stability and mitigate the Jahn–Teller distortion associated with Mn ions.

본 연구는 규사 기반의 표면처리 기법이 FRCM 복합체의 인장 성능에 미치는 영향을 정량적으로 평가하고자 수행되었다. 실험은 탄소 및 내알칼리성 유리 직물을 사용하여 표면처리 유무를 변수로 설정하였으며, 총 4개의 실험군(CN, CS, GN, GS)에 대해 인장 실험을 수행하였다. 실험 결과, 탄소 직물을 적용한 복합체는 유리 직물 대비 우수한 인장 성능을 나타냈으며, 특히 표면처리된 탄소 실험군(CS)은 비처리 실험군(CN) 대비 약 73.7%의 인장강도 향상과 66.9%의 인성 증가를 보였다. 또한 유효계수(COE) 분석을 통해 직물의 기계적 성능이 복합체에 기여하는 정도를 정량화하였으며, 표면처리가 계면 부착 성능 및 응력 전달 효율 향상에 기여함을 확인하였다. 이를 통해 FRCM 복합체가 실구조물에 적용될 경우 일체화된 거동 확보를 기반으로 구조적 성능의 향상 등의 보강 효과를 기대할 수 있는 기술적 가능성을 제시하였다. 본 연구는 FRCM 복합체의 표준화 및 성능 향상을 위한 기초 자료를 제공하며, 향후 실 구조물 적용 및 수치해석 모델링의 신뢰성 제고에 기여할 수 있을 것으로 판단된다.

As the integration of devices in electronics manufacturing increases, there is a growing demand for thermal interface materials (TIMs) with high through-plane thermal conductivity. Vertically aligned carbon fiber (CF) thermally conductive composites have received considerable attention from researchers. However, the presence of significant interfacial thermal resistance at the interface between CFs and polymer presented a significant challenge to achieving the desired thermal conductivity, even in highly vertically aligned structures. Here, in addition to developing a polymer-based thermally conductive composite based on highly oriented CFs, we employed the Diels–Alder reaction to enhance the interfacial bonding between the CFs and the polymer matrix. Notably, we proposed the thermal conductivity enhancing mechanism of the highly oriented CFs filled silicone rubber (SR) composite originated from the strengthened interfacial bonding. The results indicated that the Diels–Alder reaction facilitated an increase in the thermal conductivity of the composite from 17.69 Wm− 1 K− 1 to 21.50 Wm− 1 K− 1 with a CF loading of 71.4 wt%. Additionally, a novel nano-indentation test was employed to analyse the interfacial strengthening of composites. Our research have significant implications for the advancement of thermal management in the field of electronics and energy, particularly with regard to the development of high-performance thermally conductive composites.

Nitrite is commonly found in various aspects of daily life, but its excessive intake poses health risks like blood oxygen transport impairment and cancer risks. Accurate detection of nitrite is crucial for preventing its potential harm and ensuring public health. In this work, Cu–Co bimetallic nanoparticles (NPs) incorporated nitrogen-doped carbon dodecahedron (Cu/ Co@N–C/CNTs-X, where X denotes the carbonization temperatures) are synthesized by facile carbonization of CuO@ZIF- 67 composites. Cu and Co NPs are uniformly embedded in the carbon dodecahedron decorated by carbon nanotubes (CNTs) without agglomeration. Combining the superior catalytic from Cu and Co NPs with the electrical conductivity and stability from the carbon frameworks, the Cu/Co@N–C/CNTs-600 composite as catalyst detected nitrite concentrations ranging from 1 to 5000 μM, with sensitivity values of 0.708 μA μM–1 cm– 2, and a detection limit of 0.5 μM. Moreover, this sensor demonstrated notable selectivity, stability and reproducibility. The design of Cu/Co@N–C/CNTs-X catalysts prepared in this study can be used as an attractive alternative in the fields of food quality and environmental detection.

LTO is a commercial anode material that contributes to delivered energy and cycle stability. With affordability and high energy density, graphite faces limited cycle time and inferior stability. Here, we discussed the LTO challenges and compared the Ti-based anode from the original structure to the LTO-MXene composites, which are promising alternative anodes. Spinel lithium titanate (LTO) possesses high working voltage, stability, safety, and negligible volume change, while it suffers from low electronic conductivity that limits rate performance at large current densities. 2D Mxenes have recently drawn attention to various applications due to high conductivity, large surface area, flexibility, and polar surface benefits. We critically reviewed the synthesis approaches, morphology views, and electrochemical behavior of LTO-MXene as new anode materials in lithium-ion batteries (LIBs). There are few reports on LTO-MXene anodes in LIBs. They provide a synergistic action of LTO and MXene, enhancing the accessibility of electrolytes and reducing the distance, benefiting fast diffusion. This review paper sheds light on how the synthesis approaches can directly affect LIB configurations' durability and energy density and lead researchers to develop features of LTO anodes with promising engagement.

A technology was developed to measure the hydrogen uptake and diffusivity of polymer materials used in high-pressure hydrogen tanks and pipelines at hydrogen refueling stations. This technology involves charging hydrogen into polymer under a maximum pressure of 90 MPa, followed by depressurization. The polymer material is then placed in a cylinder partially submerged in water, and hydrogen is released from the material. The increase in volume of the released hydrogen causes a decrease in the water level in the cylinder. To track this in real-time, an image analysis algorithm based on the brightness of a crescent-shaped water level image is used to accurately measure the water level and change in hydrogen amount at the same time. This data is then used in a self-developed diffusivity analysis program to evaluate hydrogen uptake and diffusivity. Using this technology, the hydrogen uptake and diffusivity of sulfur-crosslinked nitrile butadiene rubber (NBR) composites containing carbon black and silica fillers were measured from 2 to 90 MPa. Additionally, the relationship between the physical stability of the NBR composites and their hydrogen uptake and diffusivity was investigated. To validate the effectiveness of the technology, an uncertainty analysis of the measurements was conducted, with all results showing an uncertainty within 8 %.

본 연구는 아민화 셀룰로오스 나노섬유(CNF)를 시멘트 복합체에 적용하여 기계적 및 미세구조적 성능 향상을 도모하고자 하였다. CNF는 (3-aminopropyl) triethoxysilane (APTES)를 활용해 화학적으로 개질하였으며, 이는 시멘트 수화 생성물과의 계면 결합력 및 분산성을 향상시키기 위한 목적이다. 표면 개질의 성공 여부는 주사전자현미경(SEM)과 X-선 회절 분석(XRD)을 통해 확인 하였다. 다양한 함량의 개질 및 비개질 CNF를 혼입한 모르타르를 제작하여 압축강도 및 휨강도를 평가하였다. 그 결과, 아민화 CNF는 0.2% 혼입 시 압축강도 향상 효과가 가장 두드러졌으며, 휨강도는 0.3%에서 가장 우수한 성능을 나타내었다. 미세구조 분석을 통해, 아민화 CNF가 시멘트 수화물과의 상호작용을 통해 내부 조직을 치밀하게 형성하고 공극률을 저감시키는 것으로 확인되었다. 본 연구는 화학적으로 개질된 CNF가 지속가능하고 고성능인 시멘트 복합재료 개발에 있어 유효한 기능성 첨가제로 활용될 수 있음을 시사한다.