Incorporation Of Nanotubes Research Articles

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.

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.

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). MoS1.2Se0.8-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.

Enhancing the thermoelectric properties of PEDOT:PSS films through the incorporation of g-C3N4 nanosheets and carbon nanotubes

Present study focuses on the synthesis of flexible nanocomposite film made of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), graphitic carbon nitride (g-C3N4) nanosheets, and carbon nanotubes (CNTs) and how the g-C3N4 nanosheets and CNTs affect the thermoelectric properties of PEDOT:PSS. Incorporating 10 wt% of g-C3N4 nanosheets to PEDOT:PSS improved the Seebeck coefficient to 74.3 μVK−1, ∼5 times higher than the PEDOT:PSS film. However, this led to a decrease in electrical conductivity, limiting the power factor to 335.4 μWm−1K−2. In order to address this, CNTs were added as conductive fillers. The resulting PEDOT:PSS composite, with 10 wt% of g-C3N4 and 10 wt% CNTs, showed a significant power factor of 589.8 μWm−1K−2, an electrical conductivity of 810.6 Scm−1, and a Seebeck coefficient of 84.5 μVK−1, indicating a substantial improvement in the thermoelectric performance of pristine PEDOT:PSS. The increased Seebeck coefficient in the PEDOT:PSS and g-C3N4 composite is due to reduced carrier concentration and energy filtering at the interfaces. The enhancement in electrical conductivity and the Seebeck coefficient after adding CNTs is attributed to the formation of conductive networks, increased mobility, and energy filtering at the interfaces between PEDOT:PSS and CNTs. The study suggests that combining g-C3N4 nanosheets and CNTs with PEDOT:PSS could enhance the thermoelectric performance of PEDOT:PSS-based materials.

Enhancing the Fenton catalytic activity of Fe-MOFs by incorporation of carbon nanotubes: The crucial role of C-O-Fe coordination structure

Fe-based metal–organic frameworks (MOFs) have garnered significant attention as catalysts for heterogeneous Fenton reactions, while the limited efficiency of the Fe(III)/Fe(II) redox cycle hinders their widespread use in wastewater treatment. Herein, we successfully incorporated carbon nanotubes (CNTs) into MIL-101(Fe) to modulate the coordination environment of Fe for achieving better catalytic activity. The MIL-101(Fe)/CNTs/H2O2 system shows outstanding performance in degrading various pollutants, with the catalytic activity of the MIL-101(Fe)/CNTs composites (98.8%) significantly surpassing that of MIL-101(Fe) alone (26.4%) or CNTs alone (3.5%). Multiple experimental findings suggest that this synergistic effect is primarily attributed to the C-O-Fe bridge bonds resulting from the interaction of surface carboxyl groups on CNTs with Fe in MIL-101(Fe). This unique coordination structure accelerates the redox cycle of Fe(III)/Fe(II), thereby promoting the generation of hydroxyl radicals (HO•). Furthermore, the MIL-101(Fe)/CNTs composites demonstrate excellent reusability and stability, maintaining effectiveness over a wide pH range from 3.0 to 6.5. This study provides new insights into regulating the microstructure of Fe-based MOFs to enhance their Fenton catalytic activity.

Multiscale modeling of microstructural and hygrothermal effects on vibrations of CNT-enhanced fiber-reinforced polymer composites

This work presents a multi-scale analytical and computational approach designed to predict the hygro-thermo-mechanical vibrational response of laminated composite structures reinforced with multi-walled carbon nanotubes (MWCNTs). Employing the modified Halpin-Tsai model, this study estimates the elastic properties of the MWCNT-enhanced epoxy matrix, incorporating the impacts of MWCNT agglomeration, orientation, waviness, and size-dependent characteristics. Additionally, the Chamis micromechanical model is utilized to ascertain the independent elastic constants of the nanocomposite lamina, considering environmental variables such as temperature and humidity. Subsequent analysis involves the determination of natural frequencies for both pristine and MWCNT-integrated laminated composite structures via the Finite Element Method (FEM), addressing various design-related parameters. This investigation further explores the macroscopic influences of MWCNT incorporation, boundary condition and layup scheme, along with the temperature, moisture content, and the nanoscopic impact of MWCNTs on the natural frequencies of laminated composite plates. The obtained results of the proposed multiscale modeling are compared with experimental and theoretical observations. It has been demonstrated that while the incorporation of carbon nanotubes (CNTs) can enhance the mechanical properties of nanocomposite laminae, the natural frequencies of these nanocomposite plates are adversely affected by variations in temperature and moisture content. Furthermore, the findings indicate that the microstructural characteristics of CNTs play a crucial role in determining the efficacy of the reinforcement phenomenon. The developed multi-scale methodological framework offers significant potential for the design and optimization of MWCNT-based composite structures across diverse industries, including automotive and aerospace sectors.

Electrostatic Dissipation in 3D-Printable Silicone.

In this report, we describe the incorporation of single-walled carbon nanotubes (CNTs) into 3D printable siloxane elastomers for electrostatic dissipation. The composite was characterized, focusing on how rheological and mechanical properties of the siloxane are affected at various CNT loading levels. Electrical properties were also characterized to develop materials with effective electrostatic dissipation. We demonstrate that low loadings (<1 wt %) of CNTs can be sufficiently dispersed into silicone resins that can be 3D printed, and the resulting material shows a significant improvement in electrostatic dissipation through the reduction in electrical resistivity with minimal effect on its mechanical properties.

Preparation of carbon nanotube composite solder and analysis of the thermal properties

Abstract The solder layer constitutes a crucial component of IGBT power modules. It endures significant thermal stress during operation, and the magnitude of this stress correlates with the coefficient of thermal expansion. To prevent fatigue damage to the solder layer during operation, it is necessary to reduce the solder’s coefficient of thermal expansion, thereby alleviating the impact of thermal stress. In this paper, the method of adding carbon nanotube powder to solder is proposed to solve this problem. Firstly, the relationship between thermal stress and the coefficient of thermal expansion is analyzed, and then the mechanical ball milling method is employed to prepare composite solder with a 0.05% carbon nanotube content. Scanning electron microscopy observation of the prepared composite solder reveals homogeneous mixing and uniform distribution of carbon nanotubes on the solder particle surfaces. Furthermore, thermal expansion coefficient tests were conducted on the sintered carbon nanotube composite solder, revealing a 16.2% reduction in the coefficient due to the incorporation of carbon nanotubes.

Casson hybrid nanofluid flow over a Riga plate for drug delivery applications with double diffusion

Abstract Casson fluid-mediated hybrid nanofluids are more effective at transferring heat than traditional heat transfer fluids in terms of thermal conductivity. Heat exchangers, cooling systems and other thermal management systems are ideal for use with Casson fluids. Precise control of the flow and release of medication is necessary when using Casson fluids in drug delivery systems because of their unique rheological properties. Nanotechnology involves the creation of nanoparticles that are loaded with drugs and distributed in Casson fluid-based carriers for targeted delivery. In this study, to create a hybrid nanofluid, both single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) are dispersed in a Casson fluid with Fourier’s and Fick’s laws assumptions. The Casson fluid is suitable for various engineering and medical applications due to the enhancement of heat transfer and thermal conductivity by the carbon nanotubes. Our objective is to understand how SWCNTs and MWCNTs impact the flow field by studying the flow behavior of the Casson hybrid nanofluid when it is stretched against a Riga plate. The Darcy–Forchheimer model is also used to account for the impact of the porous medium near the stretching plate. Both linear and quadratic drag terms are taken into account in this model to accurately predict the flow behavior of the nanofluid. In addition, the homotopy analysis method is utilized to address the model problem. The outcomes are discussed and deliberated based on drug delivery applications. These findings shed valuable light on the flow characteristics of a Casson hybrid nanofluid comprising SWCNTs and MWCNTs. It is observed that the incorporation of carbon nanotubes makes the nanofluid a promising candidate for medical applications due to its improved heat transfer properties.

Hybrid Nanofiller-Enhanced Carbon Fiber-Reinforced Polymer Composites (CFRP) for Lightning Strike Protection (LSP).

The aviation industry relies on lightweight carbon fiber-reinforced polymers (CFRP) for fuel efficiency, which necessitates lightning strike protection (LSP) and electromagnetic shielding due to their electrical insulating characteristics. Traditional metallic meshes used for LSP are heavy and corrosion-prone, prompting the exploration of alternatives. This research showcases CFRP nanocomposites with enhanced LSP properties through the incorporation of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs). While the enhanced conductivity in the nanofilled epoxy matrix did not impact the overall conductivity of CFRP panels, a significant damage reduction was observed after simulated lightning strike tests. Similar approaches in the literature have also noted this discrepancy, but no attempts to reconcile it have been made. This work provides a framework to explain the damage reduction mechanism while accounting for the modest conductivity improvements in the nanoreinforced CFRPs. Additionally, a simple, nondestructive method to assess surface resin degradation after a lightning strike test is proposed, based on the fluorescence of diphenyl ketones. The discussion is supported by electrical conductivity measurements, damage pattern evaluation using the proposed UV-illumination method, ATR-FTIR, and scanning electron microscopy analysis pre- and postlightning strike simulation.

Molecular Dynamics Simulations of Gas Transport Properties in Cross-Linked Polyamide Membranes: Tracing the Morphology and Addition of Silicate Nanotubes.

This study employs molecular dynamics (MD) simulations to fundamentally provide insight into the role of cross-link density in the CO2 separation properties of interfacially polymerized polyamide (PA) membranes. For this purpose, two atomistic models of pure polyamide membranes with different cross-link densities are constructed by MD simulations to conceptually determine how the fractional free volume of polyamide affects the gas separation performance of the membrane. The PA membrane with a lower cross-link density (LCPA) shows a higher gas diffusion coefficient, a lower gas solubility coefficient, and a higher gas permeability than the PA membrane with a higher cross-link density (HCPA). Moreover, the pristine and modified silicate nanotubes (SNTs) as the fast gas transport channels are incorporated into the polyamide membranes to assess the effect of the SNT/PA interface chemistry on the CO2 separation properties of the membranes. SNTs are systematically modified by three modifying agents with different CO2-philic groups and different interfacial interaction energies with the polyamide matrix. The results of MD simulations demonstrate that the incorporation of silicate nanotubes into the PA matrix increases the gas diffusivity and permeability and decreases the CO2/gas selectivity. Moreover, the membranes containing modified SNTs possessing high CO2-philicity and high SNTs/PA interfacial interactions show a high CO2 separation performance.

Enhanced physical and mechanical properties of Cu-based nanocomposites with bundled multi-layered carbon nanotubes incorporation: fabrication and comparative analysis via conventional sintering and SPS techniques

The current investigation delves into the influence of incorporating bundled multi-layered graphene sheets, specifically multiwalled carbon nanotubes (MWCNTs), on the microstructure, as well as the physical and mechanical attributes of Cu-based nanocomposites. Various weight percentages (1%, 2%, 3%, and 5%) of MWCNTs were infused into the Cu matrix, and the fabrication of these nanocomposites was conducted through the powder technology route. The fabrication process occurred under an argon atmosphere utilizing both conventional sintering and spark plasma sintering (SPS) techniques. The conventionally sintered Cu-based nanocomposite reinforced with 1% MWCNT exhibited the highest relative density (~86%), hardness (~551.12 MPa), compressive strength (~459 MPa), and outstanding resistance to wear. Conversely, the SPS-fabricated nanocomposite reinforced with the same MWCNT concentration demonstrated the highest relative density (approximately 94.25%) and compressive strength (~688 MPa), while the nanocomposite reinforced with 2% MWCNT displayed the highest hardness (~1178 MPa) and resistance to wear. Notably, a higher concentration of MWCNTs was observed to adversely affect the physical, mechanical, and wear properties of the Cu-MWCNT nanocomposites, irrespective of the chosen sintering technique for their production.

Restoration of Motor and Bladder Functions after Spinal Cord Injury via Sustained Wogonin Release from Carbon Nanotube Incorporated Hydrogels

Restoration of Motor and Bladder Functions after Spinal Cord Injury via Sustained Wogonin Release from Carbon Nanotube Incorporated Hydrogels

Synergetic effect of multiwalled carbon nanotubes on mechanical and deformation properties of engineered cementitious composites: RSM modelling and optimization

Engineered cementitious composites (ECC) have outstanding energy absorption and ductility, but their primary drawbacks continue to be their poor elastic modulus and severe drying shrinkage. Therefore, the incorporation of multiwalled carbon nanotubes (MWCNTs) to mitigate the stated drawbacks and also the influence of MWCNTs on the mechanical characteristics of ECC has been examined. However, the primary goal of this research investigation is to apply the response surface methodology (RSM) modelling for optimizing multiple objectives, effectively handling variable interactions, and achieving significant improvements. A total of thirteen mixtures were produced through RSM modelling using two input factors including different concentrations of MWCNTs at 0.05 %, 0.065 %, and 0.08 %, as well as varying concentrations of PVA fiber at 1 %, 1.5 %, and 2 %. The central composite design (CCD) technique of RSM modelling was used in the production of these mixtures. The results demonstrated that the incorporation of 0.05 % MWCNTs and 1 to 1.5 % PVA fiber together considerably enhanced all of the characteristics of the ECC. The optimum compressive strength, flexural strength, tensile strength, and modulus of elasticity of the ECC were recorded by 74.28 MPa, 14.14 MPa, 5.51 MPa, and 31.10 GPa at 0.05 % MWCNTs at 28 days correspondingly. Furthermore, the drying shrinkage is getting decreased as the extent of MWCNTs increases in ECC. It has been concluded that the use of 0.05 % of MWCNTs and 1 % to 1.5 % of PVA fiber provided good outcomes for construction purposes.

Correction: Incorporation of carbon nanotubes in sulfide-based binary composite to enhance the storage performance of supercapattery devices

Correction: Incorporation of carbon nanotubes in sulfide-based binary composite to enhance the storage performance of supercapattery devices

Ameliorating carbon capture efficiency of polysulfone membranes via collegial incorporation of zeolite imidazole frameworks and carbon nanotubes

AbstractContinuously exacerbating situation of global warming can be effectively mitigated by controlling carbon emissions from combustion processes through economically attractive membrane technology. Carbon capture efficiency of prospective membranes can be significantly improved via synergistically incorporating CO2‐selective ZIF‐300 nanoparticles and carbon nanotubes (CNTs) into polysulfone (PSF) matrix. Solution‐casting coupled with phase‐inversion processes were employed to concoct hybrid membranes containing varying loadings of both nanofillers. Manufactured composite membranes showed improved matrix structure, uniform nanofillers scattering, enhanced thermal resistance, and ameliorated nanofillers‐polysulfone interfacial adhesion as evidenced by morphological and thermal analysis. Both sorption and permeation measurements for CO2 and N2 gases performed on created membranes indicated upgraded CO2 permeability and CO2/N2 permselectivity on account of collegial impact of added nanofillers. In contrast to pristine polysulfone membrane rendering CO2 intake of 4.1 and CO2/N2 sorption selectivity of 12, hybrid membrane containing 15% ZIF‐300 and 3% CNTs uplifted corresponding values to 12 and 22, respectively. As compared to unadulterated polysulfone membrane, CO2 permeability and CO2/N2 permselectivity of hybrid membrane doped with optimized nanofillers loading of were, respectively, elevated by five‐ and three‐folds. Unique features of manufactured membranes can best be manifested in terms of their ability to maintain gas separation performance from post‐combustion effluents.

Enhancing Performance and Stability of High-Temperature Proton Exchange Membranes through Multiwalled Carbon Nanotube Incorporation into Self-Cross-Linked Fluorenone-Containing Polybenzimidazole.

Addressing critical challenges in enhancing the oxidative stability and proton conductivity of high-temperature proton exchange membranes (HT-PEMs) is pivotal for their commercial viability. This study uncovers the significant capacity of multiwalled carbon nanotubes (MWNTs) to absorb a substantial amount of phosphoric acid (PA). The investigation focuses on incorporating long-range ordered hollow MWNTs into self-cross-linked fluorenone-containing polybenzimidazole (FPBI) membranes. The absorbed PA within MWNTs and FPBI forms dense PA networks within the membrane, effectively enhancing the proton conductivity. Moreover, the exceptional inertness of MWNTs plays a vital role in reinforcing the oxidation resistance of the composite membranes. The proton conductivity of the 1.5% CNT-FPBI membrane is measured at 0.0817 S cm-1 at 160 °C. Under anhydrous conditions at the same temperature, the power density of the 1.5% CNT-FPBI membrane reaches 831.3 mW cm-2. Notably, the power density remains stable even after 200 h of oxidation testing and 250 h of operational stability in a single cell. The achieved power density and long-term stability of the 1.5% CNT-FPBI membrane surpass the recently reported results. This study introduces a straightforward approach for the systematic design of high-performance and robust composite HT-PEMs for fuel cells.

A Solvent-Templated Porous Liquid Crystal Elastomer with Tactile Sensation beyond Reversible Actuation toward Versatile Artificial Muscles.

Liquid crystal elastomers (LCEs), as a classical two-way shape-memory material, are good candidates for developing artificial muscles that mimic the contraction, expansion, or rotational behavior of natural muscles. However, biomimicry is currently focused more on the actuation functions of natural muscles dominated by muscle fibers, whereas the tactile sensing functions that are dominated by neuronal receptors and synapses have not been well captured. Very few studies have reported the sensing concept for LCEs, but the signals were still donated by macroscopic actuation, that is, variations in angle or length. Herein, we develop a conductive porous LCE (CPLCE) using a solvent (dimethyl sulfoxide (DMSO))-templated photo-cross-linking strategy, followed by carbon nanotube (CNT) incorporation. The CPLCE has excellent reversible contraction/elongation behavior in a manner similar to the actuation functions of skeletal muscles. Moreover, the CPLCE shows excellent pressure-sensing performance by providing real-time electrical signals and is capable of microtouch sensing, which is very similar to natural tactile sensing. Furthermore, macroscopic actuation and tactile sensation can be integrated into a single system. Proof-of-concept studies reveal that the CPLCE-based artificial muscle is sensitive to external touch while maintaining its excellent actuation performance. The CPLCE with tactile sensation beyond reversible actuation is expected to benefit the development of versatile artificial muscles and intelligent robots.

Hybrid nanofluids flow over a Riga plate surrounded by a variable porous medium for heat transfer optimization

Enhancing the heat transfer rate in hybrid nanofluids is significantly aided by a porous medium. The nanofluid’s heat transfer to the surrounding medium is more efficient due to the presence of a porous medium. The porous space also provides additional surface contact points for heat exchange and an intricate network of interconnected pores. This article elaborates on the incorporation of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) into water to perform hybrid nanofluids. The flow is considered over a Riga plate surrounded by a variable porous space. Various applications, including thermal management systems, microelectronics cooling, and energy conversion devices, benefit greatly from the study of hybrid nanofluid flow on a Riga plate. The similarity equations of the flow problem are easily tackled with the homotopy analysis method (HAM) built on fundamental homotopy mapping. Furthermore, with the increments in paramount parameters, the skin friction coefficient and heat transfer rate are remarkably meliorated under a higher modified Hartmann number. All reverberations are illustrated in graphs and Tables. From the obtained results it is observed that flow control capabilities are enabled by the variations in permeability in the case of hybrid nanofluids. It is also observed that hybrid nanofluids are more capable to enhance the thermal capabilities of the traditional fluids as compared to the mano nanofluids.