Search Results (6,914)

A charge-balanced aqueous hybrid supercapacitor was constructed by coupling Co-modified MnWO₄ nanorods with H₂O₂-treated carbon nanotubes (OH-CNTs) in 1 M KOH. The samples were designated by the nominal Co/(Mn + Co) precursor molar fraction; ICP-OES measured bulk Co fractions of 0.09 ± 0.01, 0.47 ± 0.03, and 0.75 ± 0.04 mol% for the nominal 0.1, 0.5, and 0.8 mol% samples, respectively. Rietveld refinement confirmed retention of the monoclinic P2/c MnWO₄ phase with only small composition-dependent lattice changes. At an active-material loading of 2.00 ± 0.05 mg cm⁻², the optimized nominal 0.5 mol% sample delivered 429.5 ± 11.0 C g⁻¹ (119.3 ± 3.1 mAh g⁻¹) at 1 A g⁻¹ and retained 280.5 ± 8.5 C g⁻¹ (77.9 ± 2.4 mAh g⁻¹) at 15 A g⁻¹. Because the positive electrode exhibits battery-type behavior, specific charge and specific capacity are used as the primary performance descriptors. Over −0.9–0 V vs. SCE, pristine CNT and OH-CNT electrodes delivered of 189.0 ± 7.2 and 246.6 ± 8.1 C g⁻¹, corresponding to electrode-level apparent specific capacitances of 215 ± 8 and 280 ± 9 F g⁻¹ at 1 A g⁻¹ after correction for the measured IR drop. These values apply to the stated 90:5:5 CNT (or OH-CNT)/acetylene-black/PVDF formulation and CNT-active-mass normalization and should not be interpreted as intrinsic capacitances of isolated commercial MWCNT powders. Charge matching based on the measured gave m⁺/m⁻ = 0.574; integration at the actual device loadings yielded q⁺ = 0.861 ± 0.015 C and q⁻ = 0.854 ± 0.015 C (q⁺/q⁻ = 1.008). The device operated over 0–1.6 V and delivered 97.9 ± 3.1 F g⁻¹ at 0.51 A g⁻¹, corresponding to 34.8 Wh kg⁻¹ at 408 W kg⁻¹ when normalized to the combined active mass of both electrodes. Three independently assembled devices retained 96.0 ± 0.7% of the initial capacitance and showed a coulombic efficiency of 98.8 ± 0.1% at the 10,000th cycle at 5.13 A g⁻¹. Device metrics are normalized to the combined active mass of both electrodes and exclude current collectors, separator, electrolyte, and packaging. Full article

Thermally sprayed metallic coatings on carbon fiber-reinforced polymer (CFRP) substrates often contain pores and microstructural defects that can reduce adhesion, durability, and protective performance. In this study, a hybrid graphene nanoplatelet (GNP)-fullerene C60 reinforced epoxy coating was applied to HVOF-metallized CFRP, while a carbon nanotube (CNT)-based surface treatment was used to modify surface wettability. Micro-CT and SEM analyses indicated morphological changes consistent with partial coverage of accessible surface-connected defects and modification of the metallized layer surface. Pull-off adhesion strength increased from 320 psi to 650 psi, accompanied by a shift from adhesive to cohesive failure. The optimal nanofiller formulation improved tensile strength from approximately 25 MPa to 56 MPa (124%) and Young’s modulus by approximately 47% compared with neat epoxy. Abrasion testing showed more than 50% reduction in mass loss, and electrochemical impedance spectroscopy indicated improved barrier performance after 200 h of salt spray exposure. CNT surface modification transformed the coating from hydrophilic to superhydrophobic behavior, achieving water contact angles above 155°, delaying ice formation, and reducing ice accumulation. These results indicate that combining hybrid nanocomposite coatings with CNT functionalization can improve mechanical, protective, and surface-functional performance of HVOF-metallized CFRP systems under the laboratory conditions investigated. Full article

In this work, three biochars were synthesized from a mixture of an abundant agricultural waste (date palm fronds) and an animal biomass (chicken manure) at pyrolysis temperatures of 700 °C (B-700), 800 °C (B-800), and 900 °C (B-900), respectively. These biochars were characterized and used as electrode materials in a capacitive deionization (CDI) process to remove salts from saline water. The CDI results show that the B-700 electrode displayed the highest desalination efficiency of 10.2% with 100 ppm NaCl. Further mixing the B-700 with 10% and 20% of multi-walled carbon nanotubes (CNT) revealed an enhanced desalination performance. For instance, a biochar-20%CNT electrode achieved a salt adsorption capacity (SAC) of 11.32 mg/g at 200 ppm NaCl, which is 7.6 times higher than that of B-700 alone. The performance enhancement is attributed to carbon nanotubes acting as conductive channels between biochar particles, thereby improving electrical conductivity and electrochemical properties of the CDI electrode. Additionally, the presence of well-known hydrophilic functional groups on CNT surfaces enhances hydrophilicity, providing a highly porous surface area. The results suggest that the CDI method with biochar–CNT electrodes offers opportunities for energy-efficient, low-cost freshwater production, with significant scaling up potential for the treatment of brackish and wastewater. Full article

In this paper, the nonlinear vibration (NV) response of carbon nanotube-reinforced composite (CNTRC) marine panels (MPs) fitted with symmetric multi-vibration absorbers (MVAs) subjected to steady, velocity-dependent hydrodynamic loads is investigated. To model actual marine conditions more realistically, the lift and drag forces varying with flow velocity were taken into account using experimentally supported Matveev-based formulations for a specific ship. Within the shell, three carbon nanotube (CNT) distribution schemes are considered: one uniformly distributed (UD) CNT configuration and two functionally graded (FG) CNT patterns, namely FG-V and FG-X. The analytical framework is further constructed using classical shell theory (CST) by incorporating geometric nonlinear terms, and the Galerkin technique is employed to obtain a reduced-order model. Thereafter, the NV response of the CNTRC-MPs is predicted through the P-T method, which relies on the joint application of the piecewise constant argument and Taylor series expansion. The results indicate that symmetric MVAs can effectively suppress NV behavior and significantly decrease the maximum NV amplitude of the panel. Moreover, the effectiveness of the proposed configuration is shown to depend on both the absorber characteristics and the reinforcement pattern of CNTs. The study demonstrates that the use of symmetric absorber systems offers a practical and efficient passive vibration-control solution for advanced marine composite panels. Full article

The demand for a versatile and portable point-of-use (POU) sensor platform has surged due to the pandemic, especially in countries with limited medical laboratory facilities. We recently unveiled a portable, non-planar, interdigitated, flow-through, porous electrode platform that automatically measures electrochemical impedance spectroscopy (EIS) signals from various biomarkers. However, the packed powder exhibited a loss of performance over time due to displacement, leaching, and poor stability. Herein, we modified the packing strategy by synthesizing the sensing material within the channel, thereby improving adhesion, structural integrity, and stability. Leveraging the exceptional thermal stability, mechanical strength, and chemical resistance of polyimide (PI), we developed a novel fabrication approach that combines liquid-phase inversion and breath-figure techniques to create a porous PI manifold with single-walled carbon nanotubes (SWCNTs) under varying humidity conditions. Scanning electron microscope (SEM) analysis revealed that lower relative humidity (RH) conditions yield larger but less uniformly distributed pores, leading to increased channel pressure. The manifold demonstrated exceptional stability under rigorous flow conditions, withstanding a high flow rate of 30 µL/min while maintaining consistent pressure-EIS responses. The device produced a measurable proof-of-concept impedance response following exposure to a femtomolar concentration of complementary target ssDNA in 1× PBS within 15 min. A formal limit of detection was not determined in the present study. We developed a mechanically stable sensor design with improved durability under repeated flow conditions by systematically optimizing synthesis conditions and manifold configuration. This innovative fabrication strategy demonstrates the importance of packing methodology in sensor design and paves the way for robust, scalable, and efficient diagnostic solutions in resource-limited settings. Full article

Pesticide and veterinary drug residues, heavy metals and other hazardous contaminants in agricultural products and food systems pose severe threats to food safety and agro-ecological security. Conventional detection techniques are plagued by complicated operations, long testing cycles and insufficient sensitivity, which fail to meet the practical requirements for rapid, accurate on-site detection and in situ remediation. This paper systematically introduces the fundamental physicochemical properties of typical carbon-based nanomaterials, including graphene, carbon nanotubes, carbon quantum dots and biomass-derived carbon. It comprehensively reviews the latest research advances of these materials in the detection of heavy metal ions, pesticide residues, mycotoxins and illegal additives, as well as in the non-destructive monitoring of food quality. Meanwhile, relevant applications of carbon-based nanomaterials in the adsorption, enrichment and catalytic remediation of heavy metals and organic pollutants in farmland soil and water environments are summarized. The intrinsic mechanisms underlying their performance in high-precision detection and environmental remediation are elaborated from the perspectives of optical sensing response and adsorption–separation effects. Furthermore, the current technical limitations and bottlenecks restricting the practical application of carbon-based nanomaterials are discussed. Combined with the industrial demands for rapid screening of agro-food safety risks and in situ treatment of farmland environments, the future development prospects of carbon-based nanomaterials in agriculture and food safety fields are outlined. This work aims to provide theoretical references for the development and industrialization of high-performance carbon-based sensing and remediation materials, and to facilitate the risk prevention and control of agro-food safety as well as the green and sustainable development of agricultural ecosystems. Full article

In-vivo diabetes detection of glucose was sought using square-wave anodic stripping voltammetry (SW), with bismuth-immobilized carbon nanotube paste electrode (BCE), and skin tattoo painted wearable circuits. The optimum analytical results indicated sensitivity of 0.0781 μg/L peak signals on the BCE. The raw voltammogram was approached within the in vivo detection ranges of 10–90 μg/L, with preconcentration times of 50 s attained. The relative standard deviation was micro ranges under optimum conditions. The analytical detection limit (S/N) was attained at a nano range of 5.5 nM. The handmade microsensor was directly used in vivo on the living fish brain and human urine. The method was applied at real time in vivo, without requiring any pretreatment and other ionic electrolyte solutions. It can be used for medicinal and other materials requiring biological-fluid detection in real time. This study was designed to be suitable for real-time unmanned remote diagnosis and therapeutic drug injection into the body, micro-needle long-term administration, wearable artificial skin tattoo sensor, and real-time control. In addition, the glasses monitor was designed to be suitable for multitasking and multi-user control sensing. Full article

To address the persistent challenge of membrane wetting during oil-gas separation in transformer condition monitoring, an omniphobic composite membrane was developed to facilitate the reliable online detection of dissolved gases. An F-CNTs/Teflon AF/PVDF composite membrane, featuring a loofah-like hierarchical structure and omniphobic properties, was fabricated via spraying-deposition strategy on the polyvinylidene fluoride (PVDF) substrate. The morphology, surface chemical composition, wettability and stability of the F-CNTs/Teflon AF/PVDF composite membrane were systematically characterized. Subsequently, the oil-gas separation performance of the composite membrane was evaluated using standard transformer oil containing dissolved gases as the feed solution. The results indicated that fluorinated carbon nanotubes (F-CNTs) were successfully modified onto the membrane surface, creating a re-entrant morphology composed of an intersecting nanotube network that mimics the hierarchical architecture of a loofah. The F-CNTs/Teflon AF/PVDF composite membrane exhibited exceptional omniphobicity, achieving contact angles of 168.2 ± 1.5° and 127.5 ± 1.0° towards DI water and mineral insulating oil, respectively. Additionally, the loofah-inspired composite membrane demonstrated robust thermal and ultrasonic stability. In oil-gas separation tests, the omniphobic membrane displayed a rapid response and high efficiency for dissolved gas extraction, achieving dynamic equilibrium within 64 min. Furthermore, the modification improved permeation efficiency by 25.6%. These results suggest that the developed omniphobic membrane is a promising alternative for oil-gas separation in the condition monitoring of oil-filled electrical equipment. Full article

This review comparatively analyzed MWCNT-reinforced thermoplastic polyester nanocomposites based on petroleum-derived (PET, PBT) and bio-based (PLA, PBS) matrices, focusing on processing methods, mechanical performance, thermal stability, electrical behavior, and recyclability. Optimal MWCNT loadings typically ranged from 0.3 to 3 wt.%; higher loadings induced nanotube agglomeration and deteriorated properties due to poor dispersion and stress concentration. Melt mixing, solution blending, direct compounding, and in situ polymerization were evaluated, and their influence on dispersion quality, interfacial bonding, and scalable manufacturability was discussed. PET exhibited the largest improvements in mechanical and thermal performance (tensile strength and modulus increases >300% in optimized systems); acid or compatibilizer functionalization of MWCNT improved PET thermal stability by approximately 20–50 °C and promoted heterogeneous nucleation. PBT reached optimal reinforcement at 0.3–1 wt.% MWCNT, yielding tensile strength increases up to ~57% alongside increased crystallinity and faster crystallization kinetics. PLA generally showed reduced tensile strength after MWCNT addition unless compatibilized (e.g., via plasticizers or grafting), whereas PBS consistently gained strength, modulus, and crystallinity but experienced reductions in ductility. Electrical percolation thresholds varied widely (0.25–14 wt.%), demonstrating that dispersion quality, nanotube functionalization, and processing route governed conductivity and percolation behavior more than matrix chemistry. Recyclability and circular economy aspects were assessed: while PET/MWCNT systems showed promise for mechanical recycling and property recovery, data on repeated reprocessing, CNT structural integrity, and long-term electrical performance were scarce; PBT recycling studies were limited, and PBS/PLA recycling with retained conductive networks remained underexplored. Based on the comparative analysis, key limitations, critical research gaps, and practical recommendations for processing, compatibilization, and end-of-life evaluation were identified to guide future work aimed at enhancing both performance and sustainability of polyester/MWCNT nanocomposites. Full article

Nano-carbon biointerfaces offer versatile platforms for cancer biomarker detection, but their progression from analytical proof-of-concept to clinically usable diagnostic evidence remains uneven. This scoping review maps 191 primary studies published from 2024 to 2026, covering nano-carbon families, surface chemistries, transduction architectures, biological matrices, and translational endpoints in cancer biosensing. The evidence space spans four nano-carbon dimensional classes: zero-dimensional carbon dots and quantum dots, one-dimensional carbon nanotubes, two-dimensional graphene-derived materials, and three-dimensional hybrid composites. Across these platforms, analytical sensitivity did not scale monotonically with nano-carbon dimensionality; instead, performance was shaped by the interaction between material architecture, biointerface chemistry, recognition strategy, transduction modality, and matrix context. A Translational Readiness Matrix showed that approximately 67% of studies remained at Low Evidence Level, whereas only approximately 10% reached Strong Evidence Level. Five recurring bottlenecks constrained translation: incomplete reproducibility reporting, limited Real-matrix Validation, scarce comparator-based clinical evidence, insufficient manufacturing-scale data, and weak regulatory or deployment planning. To address these gaps, this review proposes a nine-item minimum reporting checklist and a four-stage validation roadmap to support more reproducible, comparable, and clinically oriented nano-carbon biosensor development. Full article

Lithium-ion batteries are widely used in digital, power and energy storage fields due to their high capacity and high cycle life advantages. This paper systematically screens the formulation system and designs a high-efficiency production line that can effectively improve production efficiency, reduce production costs, and lower energy consumption per unit product. The produced nano-silicon-enhanced graphite anode material has excellent performance. The selection of silicon raw materials, types of solvents, types of dispersants, and grinding processes is studied to investigate the influence of these four factors on the wet grinding process for preparing nano-silicon. Finally, metal silicon obtained by air flow pulverization is selected as the raw material, isopropanol is used as the solvent, FA01 (carboxylic acid type) is used as the dispersant, and a two-stage wet grinding process is adopted to prepare the nano-silicon dispersion solution. Zirconia beads of 0.5 mm and 0.2 mm size are used as the grinding media for the first and second stages, respectively, with filling rates of 80% and 90%, respectively. The final prepared nano-silicon dispersion is stable in dispersion and has a narrow particle size distribution. The nano-silicon dispersion solution and the multi-walled carbon nanotube dispersion solution are mechanically ground and mixed using a sand mill. At the same time, the multi-walled carbon nanotubes are coated with the nano-silicon. Then, artificial graphite is added for compounding. Finally, through spray drying, the Si@MWCNTs@graphite (SMG) nano-silicon-enhanced graphite negative electrode material is prepared. The SMG nano-silicon-enhanced graphite negative electrode material with a silicon content of 2% has a first Coulomb efficiency of up to 84.32%. Full article

This work presents the design evolution, fabrication, and characterisation of an additively manufactured ring-type thermal airflow sensor for in-pipe flow monitoring, developed employing exclusively Fused Deposition Modelling (FDM) additive manufacturing technology and a commercially available Carbon Nanotube (CNT)-enriched Biopolymer Polylactic Acid (PLA) composite filament. The design evolution proceeds through three progressive stages. In the first stage, a flat heater element is characterised through Constant-Current (CC) Joule heating experiments in order to derive the corresponding Temperature Coefficient of Resistance (TCR) and Thermal Resistance from the obtained experimental data. Consequently, a Finite Element Method (FEM) model implemented in COMSOL Multiphysics^® and calibrated with the extracted material parameters validates the experimental temperature–power relationship and predicts the convective cooling behaviour at various airflow velocities. In the second stage, the geometry is optimised by introducing a conductive trace with a reduced-cross-section central region; as a result, an equivalent thermal localisation is achieved at approximately 26% lower supplied power with respect to the initial heating element, enabled by the design freedom inherent in the FDM process. We should note that the specific sensing geometry can also be directly embedded into any 3D-printed structural component (e.g., a bracket or housing), enabling simultaneous local thermal heating and/or thermal monitoring together with structural functionality within a single printed part. In the third and final stage—the target device—a fully monolithic ring-type airflow sensor is directly integrated into a 3D-printed pipe segment during the printing process. Under constant-current excitation at 40 mA, the device exhibits a monotonically decreasing resistance with increasing airflow (ΔR ≈ 117 Ω over 0–4 m/s) due to convective cooling, while in a single flow-interruption cycle, approximately 79% of the flow-induced resistance change was recovered upon flow removal, with a residual offset of approximately 3% of the heated baseline. A coupled electrothermal FEM model of the device further supports the experimental response by comparing the simulated temperature rise with the values inferred from resistance measurements, while also clarifying the role of the effective internal convective cooling conditions imposed by the pipe geometry. Key features of the proposed device are low raw-consumables cost, fast on-site manufacturing employing a commercially available desktop 3D printer, monolithic construction free of wire-bonded interconnections, and simplicity, indicating its potential for flow monitoring and condition-based maintenance systems aboard vessels as well as in a wide range of industrial sectors. We should note that the present characterisation was performed under laboratory conditions employing a single prototype per design stage; the effects of humidity, salt exposure, vibration, temperature cycling, and material-batch variability remain to be assessed prior to shipboard deployment. Full article

With the increasing demand for tunnel construction under extreme geological conditions such as high geo-stress, rock bursts, and fault zones, the performance requirements for shotcrete in initial support systems have become more stringent. This study develops a cross-scale structured hybrid fiber-reinforced shotcrete by incorporating alkali-resistant glass fibers including HP and HD types with different lengths and carbon nanotubes (CNTs) into a conventional shotcrete matrix. An orthogonal experimental design at four factors and four levels was adopted to investigate the effects of fiber and CNT contents on the mechanical properties and microstructure of shotcrete. Uniaxial compressive strength, splitting tensile strength, slumping, rebound rate, and microscopic characteristics such as SEM were evaluated at 3, 7, and 28 days. Results show that the optimal mix proportion is 4% HP fiber (24 mm), 2% HD fiber (18 mm), 2% HD fiber (6 mm), and 0.2% CNT. Under this formulation, the 28-day compressive and splitting tensile strengths reached 43.53 MPa and 4.85 MPa, respectively, with a rebound rate as low as 3.85%. The enhanced performance is attributed to the multi-scale reinforcement mechanism. Long fibers suppress macroscopic cracks, short fibers bridge micro-cracks, and CNTs densify the interfacial transition zone. This study provides a parametric reference for the development of high-performance shotcrete and its engineering application in complex underground excavations. Full article

This study investigates the use of silica fume as a potential physical medium for carbon nanotube (CNT) incorporation in cementitious mortars, aiming to enhance mechanical performance and improve cement-use efficiency. Four mixtures were produced with a constant water-to-binder ratio of 0.50: a reference mortar (REF), a mortar incorporating 0.2 wt.% CNTs (REFCNT), a mortar with 10 wt.% cement replacement by silica fume (REFSIL), and a hybrid system containing both CNTs and silica fume (SILCNT). CNTs were introduced using a dry pre-mixing approach with silica fume, avoiding the use of surfactants, chemical functionalization, or ultrasonication. The incorporation of CNTs alone resulted in limited mechanical efficiency, leading to a reduction in flexural tensile strength at 7 days and marginal improvements at 28 days. In contrast, the hybrid SILCNT system exhibited the best overall performance, with increases of 6.2% in flexural tensile strength, 13.7% in axial compressive strength, and 16.0% in prismatic compressive strength at 28 days, indicating improved mechanical efficiency of the composite system. Regarding the environmental indicator (EPI), REFSIL and SILCNT showed a reduced value (0.68 kgCO₂/MPa, respectively) compared to REF and REFCNT (~0.86 kgCO₂/MPa). The results suggest that the combined use of silica fume and CNTs improves the mechanical efficiency of cementitious composites, leading to lower cement-based CO₂ emission indicators. The role of silica fume in potentially facilitating CNT distribution is proposed as a plausible hypothesis based on indirect evidence, including mechanical performance trends and microstructural observations. Full article

Graphene and its derivatives have attracted sustained research interest as adsorbent materials for environmental applications, driven by their large surface area, chemically tunable surface, and compatibility with a wide range of functional modifications. This review covers recent developments in the use of graphene-based materials for water, air, and soil remediation, focusing primarily on work published over the last five years. A concise overview of graphene, its derivatives, and other carbon nanostructures, such as carbon nanotubes and fullerenes, is also provided. The main graphene derivatives are briefly described (graphene oxide, reduced graphene oxide, graphene nanoribbons, and graphene quantum dots) together with a comparative overview of the principal synthesis methods, from mechanical exfoliation and chemical vapor deposition to liquid-phase exfoliation, oxidation/reduction, and flash Joule heating. The discussion then turns to how surface functionalization and composite formation affect adsorption performance in practice. In water treatment, the results are most developed: functionalized composites have reached adsorption capacities of 484.3 mg g⁻¹ for organic dyes and 157.23 mg g⁻¹ for Cr(VI). Air purification is a smaller but growing area, with plasma-treated graphene aerogels achieving CO₂ capture capacities of 3.3 mmol g⁻¹ and retaining performance over 40 cycles. Soil remediation remains the least explored compartment, though arsenic immobilization efficiencies of up to 99.3% have been reported. Remaining challenges around scalability, behavior in real environmental matrices, and long-term ecotoxicological impact are identified and discussed. Full article