Incorporation Of Carbon Nanotubes Research Articles

A molecular dynamics study on the mechanical and tribological behaviors of nitrile butadiene rubber composites reinforced by boron nitride nanotubes

To study the enhancing effect of carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs) on the mechanical, tribological, and interfacial performances of nitrile butadiene rubber (NBR) matrices, two NBR composite models strengthened by the same weight percentage of CNTs and BNNTs are constructed. The uniaxial tensile test and pull-out simulation are respectively employed to determine the mechanical capacities and interfacial characteristics of the composites. Results indicate that the inclusion of BNNTs can endow the NBR composites with more excellent mechanical properties and better thermal aging resistance compared to that of CNTs. Moreover, about 40.78% higher in the interfacial friction force, 120.7% higher in the interfacial shear strength, and 81.25% higher in the interfacial fracture toughness are achieved for the composites by the addition of BNNTs than those by the addition of CNTs. It is found that BNNTs play a better role in retarding crack propagation. Furthermore, about 23.53% lower in the friction coefficient and 2.36% lower in the abrasion rate can be obtained by the incorporation of BNNTs than by the incorporation of CNTs. To unveil the reinforcing mechanisms on the strengthened mechanical and tribological performances, the interfacial interaction energy, mean coordination number, and radial distribution function of the NBR composites are calculated accordingly. These findings have significant value for the structural design and product development of high-performance rubber composites under extreme working conditions.

Development of All-Solid-State Potentiometric Sensors for Monitoring Carbendazim Residues in Oranges: A Degradation Kinetics Investigation

Monitoring fungicide residues in orange fruits is vital, as fungicides for orange cultivation are increasingly used to prevent yield loss. At the same time, increasing restrictions are added by regulatory organizations. For facile on-site monitoring of the fungicide carbendazim (MBC), five ion-selective potentiometric sensors are proposed and compared. The first two sensors were prepared with a precipitation-based technique using molybdate (sensor 1) and tetraphenylborate (TPB) (sensor 2), respectively. Furthermore, two ionophore-based sensors were prepared using β-cyclodextrin as ionophore together with TPB (sensor 3) and tetrakis(4-chlorophenyl)borate (TpClPB) (sensor 4) as ion-exchanger. Further incorporation of multi-walled carbon nanotubes (MWCNTs) between the graphite rod and the sensing membrane of sensor 4 (sensor 5) further improved the stability and significantly lowered the limit of detection (LOD). Their performance was evaluated according to IUPAC recommendations, revealing linear response in the concentration range 1 × 10−4–1 × 10−2 M, 1 × 10−5–1 × 10−2 M, 1 × 10−5–1 × 10−3 M, 1 × 10−6–1 × 10−3 M, and 1 × 10−7–1 × 10−3 M with a Nernstian slope of 54.56, 55.48, 56.00, 56.85, and 57.34 mV/decade, respectively. The LOD values for the five sensors were found to be 7.92 × 10−5, 9.98 × 10−6, 9.72 × 10−6, 9.61 × 10−7, and 9.57 × 10−8 M, respectively. The developed potentiometric sensors were successfully applied to determine the residue and degradation rate of MBC in orange samples. After the researched fungicide was applied to the orange trees, the preharvest interval (PHI) could be calculated based on the MBC degradation kinetics determined in the tested orange samples.

Mutual promotion of CoP/CNT/Ni2P by heterojunction structural design and intrinsic activity coupling for water splitting

The design of highly stable and active bifunctional catalysts for electrolytic water remains a significant challenge. In this study, self-supported CoP/CNT/Ni2P bifunctional catalysts with three-phase heterojunction nanostructures were constructed by a multi-step electrodeposition and phosphorylation strategy. X-ray diffraction analysis and transmission electron microscope showed that CoP/CNT/Ni2P was a three-phase heterojunction nanostructure, and scanning electron microscope results of CoP/CNT/Ni2P suggested the successful introduction of carbon nanotube (CNT). The X-ray photoelectron spectroscopy results indicate a shift in the elemental binding energy in CoP/CNT/Ni2P, which is believed to contribute to the electrocatalytic reaction. The incorporation of CNT enhances charge transfer within the multiphase catalyst and maximizes the exposure of catalytically active sites, achieving an increase in catalyst performance. As anticipated, the CoP/CNT/Ni2P catalyst displays high catalytic activity for both the hydrogen evolution reaction (61 mV at 10 mA cm−2) and the oxygen evolution reaction (342 mV at 100 mA cm−2), in addition to exhibiting long-term stability at a current density of 10 mA cm−2 over 40 h. The electrolyzer comprising CoP/CNT/Ni2P(+,−) necessitates a modest operating voltage of 1.52 V to attain 10 mA cm−2 during alkaline water splitting, thereby outperforming the commercial catalyst Pt/C||IrO2 and earlier reports. This study provides guidance for the development of ultra-high activity and durability catalysts for water splitting.

Tin sulfide dendritic hybrids enhanced by metallic carbon nanotubes for superior supercapacitor performance

This study presents a facile, one-step solvothermal approach to enhance the performance of SnS2-based supercapacitor electrodes through the incorporation of metallic single-walled carbon nanotubes (m-SWNTs) via a one-step solvothermal method. The resulting dendritic heterostructures exhibit significantly improved electrochemical properties compared to pristine SnS2. Comprehensive characterization using XRD, XPS, FE-SEM, and BET analysis reveals that m-SWNT incorporation leads to a significant 111.3 % increase in specific surface area and a 255.1 % increase in pore volume for the optimized SNSC5 sample. This structural modification translates to enhanced electrochemical performance, with SNSC5 demonstrating a high specific capacitance of 161 F.g−1 at 1 A.g−1, excellent cyclic stability (94.2 % retention after 5000 cycles), and a high power density of 84.7 Wkg−1. The synergistic effect of the dendritic morphology and m-SWNT network facilitates improved electron transport and ion accessibility. Furthermore, a symmetric solid-state supercapacitor device based on SNSC5 successfully powered LEDs when charged by a solar panel, showcasing its potential for practical energy storage applications. This work provides valuable insights into the design of high-performance electrode materials for next-generation supercapacitors.

Impact of carbon nanotubes on superconducting properties and ferromagnetism of indium-doped Bi-2212 superconductors: Critical current density enhancement

Carbon nanotubes (CNTs) was incorporated as artificial flux pinning centers within the In-Bi-2212 HTSC matrix. The research focused on polycrystalline samples with the composition (Bi1.8Pb0.2Sr1.9In0.1CaCu2O8)1-x/(CNT)x, where x varied from 0 to 0.01. XRD was employed to analyse phase formation, and lattice parameters. Magnetic measurements provided insights into the diamagnetic behaviour and highest obtained onset temperatures was (Tc = 77K) for x = 0 sample. the magnetic interactions examinations between the CNT additives and the superconducting matrix at 20 K was explored the relationships between microstructure, BSCCO phase content, magnetic hysteresis loops, calculated critical current densities, and flux densities across the samples. The experimental and theoretical results indicate that CNT incorporation significantly influences the superconducting properties of In-doped-Bi-2212, particularly its flux densities and pinning mechanisms. However, the study emphasizes the importance of carefully controlling CNT nanoparticle additions to optimize the balance between microstructural features and superconducting parameters in BSCCO HTSCs.

Simultaneous realization of efficient solar evaporation and electricity collection through dual regulation of chemical composition and pore channels

The solar-driven interfacial evaporation is a recently developed zero-energy technology for seawater desalination. However, the low evaporation rate poses a significant obstacle to its industrial application, and the collection of streaming potential formed during the evaporation process remains challenging. In this paper, we constructed a solar evaporator capable of simultaneously achieving efficient solar evaporation and electricity collection. Specifically, a double network structure hydrogel comprising polyvinyl alcohol (PVA) and TEMPO-oxidized cellulose nanoparticles nanofibers (TOCNFs) was fabricated using ice templating, with the addition of sodium lignosulfonate (SLS) to further modulate water distribution within the network. The incorporation of carbon nanotubes (CNTs) enabled the achievement of a PVA/TOCNFs/SLS (PTFS) gel-based solar evaporator. The strong electronegativity carried by the TOCNFs enhances the electrostatic repulsion in the PVA-TOCNFs network, thus improving the mechanical properties of PTFS evaporator. The introduction of SLS, which contains abundant sulfonate groups, provides certain antibacterial properties to PTFS evaporator. Due to the presence of numerous hydrophilic groups, both TOCNFs and SLS can form weak hydrogen bonds with water. Through the synergistic effect of TOCNFs and SLS, the latent heat of water in PTFS evaporator is reduced to 924 kJ kg−1, enabling an evaporation rate of 3.70 kg m−2h−1 under 1 sun irradiation. Owing to the smaller pore size relative to the Debye radius and the presence of electronegative functional groups within the pores of PTFS evaporators, an overlapping bilayer is formed when water flows through, resulting in an open-circuit voltage increase of up to 270 mV. The integration of high-efficiency solar evaporation with streaming potential collection presents a novel avenue for enhancing the utilization of solar energy.

Unlocking the potential of copper-reinforced fibre metal laminates: The influence of stacking sequences

Fibre-Metal Laminates (FMLs) are a class of advanced hybrid materials consisting of a metal layer and fibre-reinforced polymers that give an excellent combination of mechanical properties. The present study deals with the development and characterization of copper-based FMLs developed through the hand layup method by considering multiple stacking sequences for improved mechanical properties and by incorporating carbon nanotubes. Extensive tensile, flexural, fatigue, and wear tests were carried out on the FMLs. SEM analysis was also done to investigate the fracture. According to the test results, in the Type III stacking sequence where optimum 0.5% CNT content is used, the best overall tensile strength together with good flexibility, fatigue resistance, and wear resistance could be obtained. The Type III stacking sequence exhibited a maximum tensile strength of 117.85 MPa, flexural strength of 168.0 MPa, and fatigue life of 22,00,000 cycles at 50 MPa stress amplitude. Further SEM analysis has shown that enhancement in microstructural integrity actually occurred with the inclusion of CNT, especially in fiber-matrix bonding improvement and reduction of voids. The results obtained in this work indicate the suitable possibility for application in high-performance aerospace and automotive industries of copper-based FMLs. This study highlights optimization issues related to both material composition and stacking sequence toward the attainment of superior mechanical properties in FMLs.

Enhanced toughness of KZr2(PO4)3 ceramics via hydrothermal incorporation of multi-walled carbon nanotubes

The multi-walled carbon nanotubes/KZr₂(PO₄)₃ (MWCNTs/KZP) composite ceramics were successfully prepared by introducing MWCNTs during the hydrothermal process. The impact of MWCNTs addition on the crystal structure, morphology, mechanical strength, and thermal expansion properties of KZP ceramics was investigated. XRD and SEM analyses revealed that the introduction of MWCNTs did not alter the phase and crystal structure of KZP. It was observed that the MWCNTs formed a strong interfacial bond with the KZP matrix and were uniformly dispersed. Mechanical testing showed that the composite ceramic with 0.3 wt% MWCNTs exhibited significantly improved flexural strength and fracture toughness, measuring 125.08 MPa and 2.57 MPa m1/2, respectively, compared to the KZP ceramic. This enhancement was attributed to the refinement of KZP grain size and the formation of a high-strength bonding interface between MWCNTs and the KZP matrix. Moreover, the incorporation of MWCNTs not only improved the toughness of KZP ceramics but also imparted exceptional thermal properties, with a thermal expansion coefficient (TEC) ranging from −0.30 to 0.49 × 10−6/K, demonstrating outstanding near-zero low thermal expansion characteristics.

On the Effect of Fibre Orientation and MWCNTs on the Strain‐Sensing Performance of TPU/PANI Electrospun Nanofibres

ABSTRACTThe increasing demand for flexible electromechanical devices with superior stretchability, durability, thermal stability and sensitivity has driven the development of new smart functional materials to replace conventional semiconductors. This study utilises combining electrospinning and in situ polymerisation to fabricate four types of thermoplastic polyurethane/polyaniline (TPU/PANI) nanofibrous membranes with varied fibre orientation and multiwalled carbon nanotubes (MWCNTs) incorporation. The combined effects of material composition and fibre alignment on strain‐sensing performance were systematically explored. All membranes exhibited stable, symmetric ohmic behaviour under strain, with current decreasing as strain increased. Remarkable repeatability and stability were observed in cyclic current–time tests. MWCNTs addition significantly enhanced conductivity, with aligned fibres further boosting performance. Gauge factor (GF) measurements revealed that aligned TPU/PANI mats had GFs of 7 (0%–18% strain) and 14.3 (18%–40%), while aligned TPU/MWCNTs/PANI mats had GFs of 5.2 (0%–13%) and 7.3 (13%–40%). Random TPU/PANI mats showed GFs of 13.9 (0%–11%) and 23.3 (11%–40%) and random TPU/MWCNTs/PANI mats had GFs of 13.9 (0%–19%) and 24.7 (19%–40%). Each configuration demonstrated suitability for specific applications, with random TPU/MWCNT/PANI mats exhibiting the best overall performance. This research provides critical insights into optimising flexible strain sensors by tuning both material composition and fibre orientation.

High-Performance Sol-Gel-Derived CNT-ZnO Nanocomposite-Based Photodetectors with Controlled Surface Wrinkles.

We investigate the effects of incorporating single-walled carbon nanotubes (CNTs) into sol-gel-derived ZnO thin films to enhance their optoelectronic properties for photodetector applications. ZnO thin films were fabricated on c-plane sapphire substrates with varying CNT concentrations ranging from 0 to 2.0 wt%. Characterization techniques, including high-resolution X-ray diffraction, photoluminescence, and atomic force microscopy, demonstrated the preferential growth of the ZnO (002) facet and improved optical properties with the increase in the CNT content. Electrical measurements revealed that the optimal CNT concentration of 1.5 wt% resulted in a significant increase in the dark current (from 0.34 mA to 1.7 mA) and peak photocurrent (502.9 µA), along with enhanced photoresponsivity. The rising and falling times of the photocurrent were notably reduced at this concentration, indicating improved charge dynamics due to the formation of a p-CNT/n-ZnO heterojunction. The findings suggest that the incorporation of CNTs not only modifies the structural and optical characteristics of ZnO thin films but also significantly enhances their electrical performance, positioning CNT-ZnO composites as promising candidates for advanced photodetector technologies in optoelectronic applications.

In-situ synthesis and microstructural evolution of a SiC reinforced Al-50Si composite exhibiting exceptional thermal properties

Incorporating carbon nanotubes (CNTs) into Al-Si alloy to prepare in-situ SiC/Al-Si composites enhances thermal conductivity (TC) and reduces the coefficient of thermal expansion (CTE). However, challenges include CNTs aggregation and uneven SiC distribution. This study uses fluidized bed chemical vapor deposition (FBCVD) to achieve uniform CNTs coverage on Al-50Si powder. Subsequent powder hot extrusion and heat treatment above the eutectic temperature enable a gradual reaction between CNTs and Al/Si atoms, resulting in uniformly dispersed SiC within the SiC/Al-50Si composite. The formation mechanism of in-situ SiC particles and their impact on the microstructure, thermal and mechanical properties of the composite are further investigated. The formation process involves a two-step chemical reaction: lamellar Al4C3 phases transform into lamellar eutectic SiC + Al phases, which then transition into polyhedral SiC particles through epitaxial growth. This in-situ formation of SiC particles also impedes Si growth during heat treatment, refining Si particles and enhancing the composite’s properties. The resulting in-situ SiC/Al-50Si composite exhibits excellent thermal and mechanical properties, including a high TC of ∼162 Wm-1K−1, a low CTE of ∼ 8.7 × 10-6/K, and a good bending strength of approximately 253 MPa at room temperature.

Photo-thermal and temperature-regulated sodium alginate-g-mPEG/carbon nanotube hybrid fibers with improved tensile strength

Despite the remarkable potential of phase change fibers for energy storage, their practical deployment has been hindered by two crucial challenges: inadequate external thermal stimulation to induce phase transition and leakage of the phase-change material. In this study, we successfully incorporated carbon nanotubes (CNTs) into a solution of sodium alginate grafted polyethylene glycol monomethyl ether (SA-g-mPEG) and utilized wet spinning processing to fabricate CNTs/SA-g-mPEG hybrid fibers with enhanced photo-thermal conversion and robust solid-solid phase change capabilities. Upon exposure to sunlight for merely 60 s, the hybrid fibers achieved a remarkable peak temperature of 40 °C. Upon cessation of sunlight exposure, these fibers demonstrated a gradual release of thermal energy, thereby underlining their exceptional photothermal conversion and temperature regulation capabilities. Furthermore, DSC analysis revealed that, at an optimal grafting ratio of 36.6 %, the hybrid fibers exhibited ΔHc and ΔHm values of 48.23 J/g and 50.83 J/g, respectively. Notably, hybrid fibers with a grafting ratio of 20.2 % demonstrated substantial enhancements in tensile properties, achieving a maximum breaking strength of approximately 2.02 cN/dtex—an impressive 11.3 % increase compared to SA-g-mPEG composite fibers. Our findings suggest that CNTs/SA-g-mPEG hybrid fibers hold immense promise for applications in body heat storage, fabric temperature regulation, and related fields.

3D micromechanics assisted finite element approach for bending analysis of straight/wavy CNT-reinforced multi-scale hybrid composite plate

This study examines the micromechanical and structural behavior of straight and wavy carbon nanotube (CNT) reinforced multi-scale fiber-reinforced hybrid composite (MFRHC) plates. An important feature of MFRHC is the incorporation of nano-scale CNTs into two-phase carbon fiber-reinforced composites (CFRC), enhancing their micromechanical and macroscopic properties, particularly the bending and stress behaviors. In CNT fiber-reinforced composites, the fiber waviness can arise from manufacturing imperfections which demands in-depth analysis of MFRHC plates reinforced with both straight or wavy CNTs to characterize their relative influences. In this work, the CNTs are assumed to be continuous and distributed uniformly within the CFRC, and the waviness is considered to be sinusoidal spanning both longitudinal and transverse planes. A mathematical formulation is devised, based on a three-dimensional mechanics of materials (MOM) model, to analyze the micromechanical behavior of the hybrid composite and the model’s accuracy are compared with the multi-inclusion Mori-Tanaka method and the Voigt/Reuss rule of mixtures. The MOM model indicates that the waviness pattern of the CNTs significantly influences the effective stiffness properties of MFRHC in comparison to that of the straight CNTs. Following this, a finite element model is constructed to investigate the bending deflection and stress properties of a simply-supported symmetric cross-ply (0/90/0) MFRHC laminate under sinusoidal transverse loading, utilizing first-order shear deformation theory (FSDT). The results suggest that the bending deflection decreases for the MFRHC laminate when the waviness factor ( Ψ ) is ≤ 0.05 , but increases when Ψ > 0.05 . Finally, the bending stress behavior is examined for both straight and wavy CNT-reinforced MFRHC laminates considering their geometrical parameters ( a / h , z / h ), and the CNTs’ waviness factor ( Ψ ), respectively.

Hybrid CoFe2O4-CNTs-graphene: Synthesis and characterization for energy storage devices

Hybrid materials play a crucial role in a spectrum of energy storage devices. Among them CoFe2O4–CNT–graphene hybrid stands out as versatile magnetic materials with wide-ranging applications spanning electronics, magnetism, and sensor industries. In this study, we synthesized CoFe2O4–CNT–graphene hybrid utilizing ultrasonication method. This fabrication method resulted in the formation of CoFe2O4 nanoparticles, along with bamboo-like carbon nanotubes (CNTs) and graphene nanosheets which collectively establish an open three-dimensional structure. Thorough analyses were conducted on the synthesized nano-composites employing various characterization techniques such as XRD, FT-IR, Raman and FESEM. Further characterization through XPS confirmed the formation of spinel ferrites, detecting the presence of carbon sp2, C1s, carboxylates (O-C-OH), and sp3 carbon, indicating the presence of carbon‑carbon (CC) bonds and confirms the energy levels of Co2p1/2 and Co2p3/2 indicating the effective incorporation of CFO onto the CNT/graphene surface. Analysis of dielectric parameters revealed promising characteristics for high-frequency devices, attributed to low dielectric loss, high quality factor, short relaxation time, and diverse responses exhibited by these materials. The M–H loops of the composite samples displayed ferromagnetic hysteresis behavior due to the presence of ferrite in the matrices. The coercivity value shows a slight improvement in the hybrid samples, while saturation magnetization values decrease, indicating a 1:1 weight ratio of ferrite particles to the host matrix with the incorporation of nonmagnetic CNTs and graphene, and the Hc value increases with the addition of these carbon-based materials due to increased surface anisotropy energy. Upon evaluation of dielectric and magnetic properties the hybrid materials demonstrated an enhanced dielectric and magnetic properties which render these materials suitable for utilization across a spectrum of energy storage devices.

Designing Mo-based transition metal dichalcogenides for sustainable hydrogen production: Anionic substitution and DFT insight

Anionic substitution is an effective approach to optimize the catalytic activity of Mo based transition metal dichalcogenide (TMD)- MoS2 towards hydrogen evolution reaction (HER). By optimizing the S-to-Se ratio, materials with the ideal Gibbs free energy of hydrogen adsorption (ΔGH) values are synthesized (MoS2, MoS1.4Se0.6, MoS1.2Se0.8, MoSSe, MoSe2) and their HER performance is examined in 0.5 M H2SO4 solution. Density functional theory calculations of hydrogen adsorption energy on the surface of the electrocatalysts show that Se substitution facilitates electron transfer between the catalyst surface and the hydrogen donor, thereby lowering the additional potential required for water splitting, making MoS1.2Se0.8 the most favorable HER electrocatalyst with the lowest value of adsorption energy. Further enhancement in the electrocatalytic activity of mixed anion TMDs has been achieved by the incorporation of carbon nanotubes (CNTs). MoS1.2Se 0.8-CNT nanocomposite exhibits superior HER performance with an overpotential of 118 mV and a Tafel slope of 63 mV/decade as compared to MoS1.2Se0.8 sample owing to the synergetic effect from CNTs and MoS1.2Se0.8.

Flexible beads-on-string hierarchically porous carbon nanofiber/nanotube composites for enhanced capacitive deionization performance in water desalination

Capacitive deionization (CDI) has garnered significant interest for desalinating water and wastewater. However, electrode materials have remained a primary constraint in CDI technology. This study incorporated carbon nanotubes (CNTs) into a polyacrylonitrile (PAN) solution to synthesize a hierarchically porous activated carbon nanofiber (ACNF)/CNT composite. The ACNF/CNT composite possesses a highly flexible structure characterized by a distinctive beads-on-string morphology. It exhibits a specific surface area of 699 m2/g, a specific pore volume of 0.448 cm3/g, and an average pore width of 3.38 nm. The composite is composed of micropores (38 %), mesopores (59 %), and macropores, creating a multi-scale porous architecture. The surface capacitance of the ACNF/CNT composite is six times greater than that of the ACNF alone, and its charge transfer resistance is reduced to one-tenth. Furthermore, the electrosorption capacity of the ACNF/CNT composite as CDI electrodes was found to be 17.3 mg/g for a 500 mg/L NaCl solution, demonstrating stability over 30 cycles. Kinetic studies suggest that the mesopore-rich beads-on-string structure enhances intraparticle diffusion and the electrosorption process. The ACNF/CNT composite also demonstrates exceptional flexibility and mechanical stability, which are crucial for its application at a pilot scale. This study introduces a novel hierarchically porous electrode material for CDI desalination.

Effect of carbon nanotube incorporation on the mechanical and physical properties of hydroxyapatite/glass ionomer nanocomposite

This manuscript discusses the potential use of multi-walled (MW) carbon nanotubes (CNTs) as a filler material in hydroxyapatite/glass ionomer cement HA/GIC nanocomposite to enhance its properties: mechanical and physical. Four different proportions (1, 2, 3, and 5 wt%) of CNTs were added to the HA/GIC nanocomposite to determine the optimum ratio that can lead to the best properties of the new nanocomposite biomaterial. Mechanical mixing technique followed in dentistry was used in preparing all samples. FTIR, PSA, XRD, TEM, and SEM were used to characterize the fabricated Pellets. In addition, the new nanocomposite samples were evaluated using compressive and diametral tensile tests. Overall, increasing the weight ratio of CNTs added to the nanocomposite (from 1 to 5 wt%) caused about a 40% reduction in the compression strength of the samples. However, a slight increase (about 4%) was detected at 2 wt% CNTs samples. Also, a distinct increase in the elasticity of the composite (about 50%) was reported. The best results of diametral tensile strength were found at a 3 wt% CNTs. Furthermore, for all samples, adding CNTs to the composite changed the sample’s color from A2 and B2 to totally black color.

Heat transfer enhancement using ternary hybrid nanofluid for cross-viscosity model with intelligent Levenberg-Marquardt neural networks approach incorporating entropy generation

Thermal heat transfer analysis of trihybrid nanofluids using an intelligent Levenberg-Marquardt neural network (ANN-LMA) approach, with a focus on entropy generation, has been conducted. The flow equations were modeled in Cartesian coordinates and simplified using dimensionless variables. Partial differential equations were converted into ordinary differential equations through appropriate similarity transformations. These ordinary differential equations were then solved using the finite element method applied to a data set evaluated from (ANN-LMA) approach. This dataset can be input into MATLAB to generate predicted solutions for flow patterns. The ANN-LMA technique was employed to evaluate the efficiency of heat transfer characteristics for nanofluids in various scenarios. Incorporating carbon nanotubes (both single-wall (SWCNT) and multi-wall (MWCNT)) along with iron oxide in water, the study demonstrates their effectiveness in enhancing heat transfer. These nanofluids have broad industrial applications, such as in coolant enhancement, cancer therapy, and solar radiation management, and show promising results. This study specifically examines the flow properties of water-based CNT cross-trihybrid nanofluids over a convectively heated surface, leveraging their unique characteristics. Improvements in heat transfer are achieved through the introduction of dissipative heat, thermal radiation, and external heat sources or sinks. The performance of the computational solver was assessed using error histograms, regression analyses, and Mean Squared Error (MSE) results. The physical significance of the designed factors is graphically depicted and discussed in detail. It was found that radiative heat increases surface heat energy through substantial accumulation, thereby enhancing heat transfer properties, while dissipative heat, due to Joule dissipation and other external sources, significantly raises the fluid temperature.

Innovative Core–Shell Tubular Structure in Polymer/Manganese–Nickel Oxide/Carbon Nanotube Blends for Electrochemical Components

ABSTRACTTo address the issue of electrochemical performance degradation resulting from redox reactions during the charging and discharging of supercapacitors, we introduced a novel electrode material featuring a core–shell attachment structure (PANI@(MnO2 + NiO)) with the incorporation of carbon nanotubes (CNTs). The introduction of CNT on top of the core–shell structure by a simple chemical synthesis method helps to improve the double‐layer capacitance and Faraday capacitance of the composite. Thus, multiple synergistic effects can be produced to improve charge storage capacity. The morphology structure and electrochemical properties of PANI@(MnO2 + NiO)@CNT were analyzed. In a three‐electrode configuration, the specific capacitance of the composite is 327 F g−1 at a current density of 0.5 A g−1. Remarkably, the capacitance retention rate exceeded 75% after 5000 charge–discharge cycles. Calculations indicate that in a supercapacitor employing a 1 M Na2SO4 electrolyte, the composite demonstrated energy and power densities of 48.1 W h kg−1 and 999.9 W kg−1, respectively. This kind of core–shell structural composites achieved electrochemical properties in line with expectations through a simple chemical synthesis method. As a practical application of supercapacitor electrode materials, PANI@(MnO2 + NiO)@CNT have better electrical properties than similar materials and have broad application prospects in industrial production.

Underwater Non‐Contact and Ultra‐Fast Adaptive Self‐Healing Elastomers Based on Programmable Dissociation of Dynamic Bonds

AbstractMost of the reported self‐healing materials focus on the structure and function recovery, the influence of the damage degree on the self‐healing process has been rarely studied. In this study, an elastomer with an adaptive self‐healing function is developed based on programmable dissociation of dynamic urea bonds. The stored entropy and reversible hydrogen bonding enable the elastomer with room‐temperature self‐healing performance as the scratch depth is less than 100 µm. Thermal treatment at 75 °C is capable of inducing the cleavage of secondary urea bonds, which accelerate the dissociation of the network, leading to the repair of the middle‐size damage. Continuous increasing the temperature to 120 °C enables the dissociation of primary urea bonds, which causes further dissociation of the network, resulting in the repair of large‐scale damage. This damage‐adaptive self‐healing performance can be well maintained in an aqueous environment, and obvious improvement in the healing rate is achieved due to the water‐accelerated dissociation of urea bonds. The underwater self‐healing rate is more than 360 times faster than that in the air. Incorporation of carbon nanotubes into the network enables remote self‐healing function due to the photo‐thermal transition after irradiated by NIR light, displaying great potential in underwater gas or liquid transportation.