Triple-walled Carbon Nanotubes Research Articles

Growth of Helical Coiled Double and Triple Walled Carbon Nanotubes at Low Temperature using FeMoMgO catalyst

Abstract Helical coiled double and triple walled carbon nanotubes (CNTS) were synthesized using chemical vapor deposition (CVD) method using FeMoMgO catalyst. The FeMoMgO catalyst was prepared using combustion process followed by multi walled CNTs synthesize. The final products were characterized by X-Ray diffraction (XRD), FT-IR, SEM, TEM and FESEM (surface morphology) along with electron dispersion X-ray spectrometer (EDX). The XRD results show that Fe is well incorporated with Mg which indicates crystalline in nature. FT-IR, results confirm the presence of functional group and metal ion. FESEM indicates the formation of larger and non-uniform particles with higher active sites. SEM and TEM results show that at low temperature coiled CNTs were formed with 2-5nm in diameter. In conclusion that Helical coiled double and triple walled CNTs were synthesized using FeMoMgO Catalyst at low temperature.

Investigation of Electromagnetic Wave Propagation in Triple Walled Carbon Nanotubes

This study examines the behavior of electromagnetic wave propagation in a unique and complex three-walled carbon nanotube structure. The structure is formed by nesting three distinct nanotubes, and the interactions between them are thoroughly analyzed, taking into account their varying electromagnetic, material, and nano properties. The structure is designed at a nanoscale to provide a comprehensive description of electromagnetic wave propagation, including the electromagnetic interaction between the second nanotube, located in the middle of the structure, and the other two nanotubes situated in both the inner and outer portions of the structure. This study presents novel findings that differ from existing literature on the subject, contributing to our understanding of this important area of research.

Enhanced mechanical properties, anti-biofilm activity, and cytocompatibility of a methacrylate-based polymer loaded with native multiwalled carbon nanotubes

ObjectivesWe aimed to optimize the mechanical and biological properties of a conventional methacrylate-based dental polymer by loading it with double- and triple-walled carbon nanotubes as growth (DTWCNTG). MethodsA formulation of bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate (mass ratio = 2:1) was mixed with DTWCNTG at concentrations of 0.0% (control), 0.001%, 0.005%, and 0.010%. The concentrations were physicochemical and morphologically evaluated, and antibacterial activity was assessed by seeding a Streptococcus mutans strain (ATCC 25175) on the experimental polymeric surfaces. Cellular survival and osteodifferentiation were evaluated in epithelial (HaCat) and preosteoblast cells (MC3T3-E1). ResultsThe 0.001% DTWCNTG concentration yielded higher compressive strength, elastic modulus, flexural strength, flexural modulus, water sorption, and solubility than the control. The degree of conversion and color did not significantly change with a low amount of DTWCNTG incorporated into the polymer. Antibacterial activity significantly improved when tested on the 0.001% DTWCNTG discs. No groups showed cytotoxicity in a short-term analysis and adding DTWCNTG favored MC3T3-E1 mineralization over the control, particularly in the 0.001% formulation. SignificanceThe micro-addition of 0.001% DTWCNTG confers mechanical resistance, antimicrobial properties, and bioactivity to methacrylate-based polymers without significantly compromising color. Incorporating DTWCNTG improved dental composite properties and could be a biomodified material for minimally invasive procedures.

Influence of gradually vacating hexagonal patterns composition of C[sbnd]C bond in TWCNTs molecular structure using the FE method for vibrational analysis

The authors use the FE research to analyse and predict the oscillational performance of TWCNTs (Triple-Walled Carbone Nanotubes) in this work. Different types of nanotubes like chiral, zigzag, and armchair as well as different lengths and diameters are used for analysis purpose. The novelty is authors included the chiral structure which is difficult to model for simulation purpose. The approach employed here to account for the variation in length in atomic models produced by removing hexagonal patterns has either never been utilised or has very little evidence. As a result, this technique's use is distinct and novel. Moreover, the authors investigate the effect of gradually removing the hexagonal patterns which contain the Carbon-Carbon(CC) bond ring in triple-walled carbon nanotube models. Molecular structural mechanics methodology is used for developing and simulations of armchair, zigzag and chiral triple walled carbon nanotube (TWCNTs). The process of removing the Carbon-Carbon bond ring from the outside wall of TWCNTs by maintaining the inside walled unchanged. Authors analysed the resonant frequencies for different attached masses ranging from 10−16to 10−23gm on TWCNTs and different boundary conditions for TWCNTs.

Some approximate buckling solutions of triple-walled carbon nanotube

The present investigation analyses the critical buckling studies of triple-walled carbon nanotube using the Euler─Bernoulli model. The present study deals with three different boundary conditions, namely, simply-simply, clamped-clamped, and clamped-simply supported carbon nanotube. Using Bubnov─Galerkin and Petrov─Galerkin methods, the continuum model estimates the critical buckling load. The main advantage of these two approximate methods is to obtain a quick and valid result. The first and second Euler critical buckling loads decrease with the increase of length to outer diameter ratio for boundary conditions like simply-simply, clamped-clamped, and clamped-simply supported. Interestingly, the increase in the length to outer diameter ratio results in the rise in third Euler critical buckling for all three different boundary conditions. These two approximate methods provide reliable buckling load estimation using suitable polynomials.

Carbon Nanotubes and its Application in Nanotechnology

Carbon nanotubes often refer to single-wall carbon nanotubes (SWCNTs) with diameters in the range of a nanometer. Single-wall carbon nanotubes are one of the allotropes of carbon, intermediate between fullerene cages and flat graphene. Carbon nanotubes also often refer to multi-wall carbon nanotubes(MWCNTs), consisting of nested single-wall carbon nanotubes, weakly bound together by van der Waals interactions in a tree ring-like structure. If not identical, these tubes are very similar to long straight and parallel carbon layers, cylindrically arranged around a hollow tube. Multi-wall carbon nanotubes are also sometimes used to refer to double and triple wall carbon nanotubes. Carbon nanotubes can also refer to tubes with an undetermined carbon wall structure and diameters less than 100 nanometers. While nanotubes of other compositions exist, most research has been focused on the carbon ones. The length of a carbon nanotube produced by common production methods is typically much larger than its diameter. Thus, for many purposes, end effects are neglected and the length of carbon nanotubes is assumed infinite. Carbon nanotubes can exhibit remarkable unique properties. These include electrical conductivity, while others are semiconductors. They also have exceptional tensile strengthand thermal conductivity, because of their nanostructure and strength of the bonds between carbon atoms. In addition, they can be chemically modified. Thus, due to their variable, unique properties, carbon nanotubes have found applications in many realms such as electronics, optics, composite materials nanotechnology, and other applications of materials science. In addition, carbon nanotubes can be integrated into other molecules to form novel structures with unique properties, different from the individual reactants. These unique products have also found application in many realms of nanotechnology

Power Withstanding Capability and Transient Temperature of Carbon Nanotube-Based Nano Electrical Interconnects

This paper exhibits the electrothermal modelling and evaluation of Carbon Nanotube (CNT) based electrical interconnects for electronic devices. The continuum model of the CNT is considered and the temperature across interconnect is predicted for the given power. Finite element modelling software COMSOL Multiphysics is used to carry out the simulations. The results are compared with Al and Cu interconnects. An electrothermal analysis is also carried out to obtain the temperature for the given power for Single-Walled CNT, Double-Walled CNT, Triple-Walled CNT, and Multi-Walled CNT. Results show that the CNT interconnects performs better when compared to Al and Cu interconnects. The power withstanding capability of CNT is 68.75 times more than Al and 32.35 times more than Cu. Based on the transient analysis, the time taken by the CNT interconnects to reach a steady temperature is obtained as 0.007 ns. On the application of power, Cu and Al interconnects takes 0.1 ns to reach the steady-state temperature. The nanostructured CNT based electrical interconnects would play a considerable role in replacing Cu and Al electrical interconnect applications for micro and nanoelectronic devices.

Dynamic analysis of wave propagation and buckling phenomena in carbon nanotubes(CNTs)

The present study focuses on analysing the behaviour of wave propagation in carbon nanotubes along with the characterization of the buckling phenomenon. The carbon nanotubes are modelled as continuum shells that utilize the nonlocal theory of elasticity as these consider the small effects of the nano structures. The expression for the dispersion relation of the wave propagation in single-walled carbon nanotube (SWCNT) and the double-walled carbon nanotubes (DWCNTs) are achieved using a suitable mathematical treatment. For the case of SWCNT, a combined effect of uniform external lateral pressure, uniform axial pressure, stretching of middle surface, the shearing force due to the torque applied, scaling effect are considered, which presents a new concept. The van der Waals (vdW) interaction, additionally, is regarded for the case of DWCNTs. Moreover, the expression for the buckling phenomenon of the DWCNTs and the triple-walled carbon nanotubes (TWCNTS) taking account of the effect of stretching of middle surface, the shearing force due to torque applied, scaling effect, vdW interaction, and net pressure due to vdW interaction has been established. As a special case of the problem, the deduced results of the present study are found to be well-matched with the pre-existing results, hence, validates the undertaken study. The phase velocity and buckling load curves are manifested graphically using numerical data of two distinct kinds of DWCNTs and TWCNTs depending on the armchair configuration. The influence of various affecting parameters the phase velocity and buckling load curves are noted and are illustrated in tabular form. The study may find its potential application for some engineering problems dealing with the characterization of CNTs and wave propagation through them under the combined effect.

Guiding of protons through radially deformed triple-wall carbon nanotubes

Subject of this study is a theoretical investigation of the channeling of high energy protons with the radially deformed triple-wall carbon nanotubes (TWNTs). Specifically, we chose a proton energy of 1 GeV and perfect and the radially deformed TWNTs (15, 0)@(10, 0)@(5, 0) of radial strengths $$\eta = 0.1, 0.2$$ and 0.3. We presented the channeling potential within the perfect and deformed TWNTs and corresponding spatial and angular distributions of channeled protons. We treated the problem relativistically. We also analyzed the case where proton beams enter nanotube under different incidence angles. We analyzed two cases $$L = 1$$ and 5 $$\mu m$$ . We also varied the value of incidence angle of proton beam and calculated the efficiency of nanotube channeling. This is the first time that we presented spatial and angular distributions of channeled protons with radially deformed TWNTs with angular effect of proton beam, and also, for the first time we presented their channeling efficiency. Our results show that the spatial and angular distributions depend strongly on the nanotube lengths, incident angle of the proton beam, and on the level of radial deformation of nanotube. Multi-wall nanotubes (MWNTs) are better candidates for realization of ion guiding than single-wall nanotubes (SWNTs) because it is easier to produce them straight. Also, deformation of the nanotube and the incident proton beam under some initial angle with respect to the nanotube axes represent realistic situation. That is why we believe that these results may be useful for production and guiding of nanosized ion beams by nanotubes.

Stability analysis of double-walled and triple-walled carbon nanotubes having local curvature

In this study, stability loss research has been made for composite material containing a locally curved one double-walled carbon nanotube and one triple-walled carbon nanotube separately. The research has been made within the scope of piecewise-homogenous body model by the use of three-dimensional linearized theory of stability (TDLTS). The carbon nanotubes are resistant to tension, but as they contain large gaps in their structure, their resistance to compression is very low. For this reason, searching the behaviors of nanotubes under compression is very important. The van der Waals forces between the walls of the carbon nanotube have been considered. It has been thought that the referred composite material is under the effect of uniformly distributed normal forces in the direction of carbon nanotube at infinity. In the model, ideal contact conditions have been used between the nanotube and the matrix. In addition, the effect of increasing the number of layers of the nanotube on the critical load has been investigated. The results obtained from this study will be able to guide in the implementations relevant to modeling of mechanical behaviors of the addressed composite material. Thus, the limits required to be considered in the production of composite material containing double-walled and triple-walled nanotubes with local curvature have been obtained.

Normal stress distribution in infinite elastic matrix with a locally curved triple-walled carbon nanotube

Nanocomposite materials are produced by using of nanotubes, the most significant structural elements of nanomaterials used in nanotechnologic applications. In the reinforcement (in the fibers) of the structure of composite materials, the appearance of the self-balancing stresses results from the initial curvature, caused by either structural reasons or technological processes. Because of exceeding safety limits of material caused by high magnitude self-balancing stresses, investigating the mechanical behaviors of the material theoretically, both under tensile and compression in the direction of strengthening (fiber) is essential for the engineering. Unlike the literature, in this study, composite materials containing triple-walled nanotube are investigated in the scope of the piecewise homogeneous body model by using of geometric non-linear exact equations of the 3-D theory of elasticity. The normal stress analysis, on the outermost surface of the carbon nanotube and the matrix intersection, is investigated under various external effects. Nanotube is first formed as having a small local curvature. Van der Waals forces existing between the carbon nanotube walls are taken into consideration.

CNT-sandwiched copper composites as super thermal conductors for heat management

Due to outstanding electric conductance, copper is widely used as wires in electricity and as interconnects in microchips, where the thermal conductivity could be enhanced by compositing with carbon nanotubes (CNTs). Here, we have numerically designed a class of sandwich-like CNT/Cu/CNT nanotubes which possess high thermal conductivity revealed by molecular dynamics simulations. The enhancement factor of thermal conductivity of the composite using single-walled CNT is 37.5 times of that of a 5-nm-radius copper nanowire. The enhancement factor is further enlarged to 58.2 using triple-walled CNT in the outer side. The atomic stress analysis manifests that the thermal stresses are concentrated in the region around the CNT/Cu interface. The stabilities and larger enhancement factors at high temperatures imply high temperature applications of these CNT-sandwiched tubular copper nanocomposites in heat management and electronics. CNT-Sandwiched copper composites greatly increase the thermal conductivity over copper nanowires. • Introduce a sandwich-like CNT/Cu/CNT nanotubes. • Over 37.5 times boosting the thermal conductivity. • Stable at high temperatures with promising applications.

Buckypapers of carbon nanotubes and cellulose nanofibrils: Foldable and flexible electrodes for redox supercapacitors

In this work, we report a buckypaper composite with properties suitable for high performance electrodes of redox supercapacitors. The synthesis employs a specific combination of the double- and triple-walled carbon nanotubes (FWCNT) with cellulose nanofibrils (CNF), with dimensions of 20–50 nm in width and lengths of up to several hundred microns. The generated composite (BP/CNT@CNF) preserves the structure of the FWCNTs and ensures greater wettability, without significant damage to electrical conductivity. When compared to a buckypaper produced without CNF, BP/CNT@CNF is completely moldable and flexible, with an increase of about 375% in tensile strength, and 400% in the maximum strain. As electrodes, BP/CNT@CNF is stable in different aqueous redox electrolytes at different pHs containing hydroquinone (HQ in 1.0 M H2SO4), potassium hexacyanoferrate(II) (K₄[Fe(CN)₆] in 3.0 M KOH) and KBr in neutral medium. In all media, excellent capacitance retentions are obtained, evaluated in 12,000 cycles. The best electrochemical performances are obtained with HQ/H2SO4 as a redox electrolyte. High specific capacitance values are found from 1 A g−1 (380.8 F g−1) to 15 A g−1 (216.1 F g−1), with energy and power densities corresponding to 28.2 W h kg−1 and 3974.7 W kg−1, respectively, calculated at electrode level.

Critical Buckling Load of Triple-Walled Carbon Nanotube Based on Nonlocal Elasticity Theory

The present paper investigates the nonlocal buckling of Zigzag Triple-walled carbon nanotubes (TWCNTs) under axial compression with both chirality and small scale effects. Based on the nonlocal continuum theory and the Timoshenko beam model, the governing equations are derived and the critical buckling loads under axial compression are obtained. The TWCNTs are considered as three nanotube shells coupled through the van der Waals interaction between them. The results show that the critical buckling load can be overestimated by the local beam model if the small-scale effect is overlooked for long nanotubes. In addition, a significant dependence of the critical buckling loads on the chirality of zigzag carbon nanotube is confirmed, and these are then compared with: A single-walled carbon nanotubes (SWCNTs); and Double-walled carbon nanotubes (DWCNTs). These findings are important in mechanical design considerations and reinforcement of devices that use carbon nanotubes.

Interfacial characteristics of a carbon nanotube-polyimide nanocomposite by molecular dynamics simulation

Abstract With molecular dynamics simulations, nanocomposites were characterized that are comprised of a polyimide (PI) polymer and carbon nanotubes (CNTs) with the same outer diameter but with one, two, or three walls. The simulations indicate that the PI/CNT interaction is strong, regardless of the number of CNT walls, and that there is some degree of alignment of the PI chains near the CNT interface. As the number of CNT walls increased, the density of PI chains near the CNT interface also increased and the average radius of gyration of the PI chains decreased, and these observations were attributed to changes due to the intertube van der Waals interactions. From simulations of the constant force pullout process of the CNT from the PI matrix, the limiting pullout force was calculated to be higher for the triple-walled CNT than for the single-walled one. The interfacial shear strength of the nanocomposites was also calculated from the pullout energy, and the results indicate that increasing the number of walls is a critical factor for enhancing the interfacial stress transfer during tension.

A novel triple-walled carbon nanotube screwing oscillator: a molecular dynamics simulation

A novel triple-walled carbon nanotube (TWCNT) screwing oscillator is proposed, in which screwing motion signals of both inner tube and middle tube are outputted simultaneously by applying an axial excitation to the inner tube and a rotating excitation to the middle tube. The molecular dynamic method is used to investigate the oscillatory behavior of the TWCNT oscillator under screwing motion. In the simulation process, the fixed outer tube acts as the oscillator stator, while the inner tube and the middle tube keep free oscillation after applying a certain initial excitation respectively. The simulation results show that the rotation frequency of the inner tube increases with the increase of the initial rotation excitation frequency of the middle tube when the inner tube is pulled out at a certain distance, and eventually tends to a stable value slightly lower than the rotation excitation. When the applied initial rotation frequency is within 400 GHz, the self-excited stable ration frequency (<inline-formula><tex-math id="M4">\begin{document}$ {\omega _{\rm{I}}}$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20200821_M4.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20200821_M4.png"/></alternatives></inline-formula>) of the inner tube can be expressed as a function of the initial rotation excitation frequency (<inline-formula><tex-math id="M5">\begin{document}$ {\omega _{{\rm{M}}0}}$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20200821_M5.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20200821_M5.png"/></alternatives></inline-formula>), <inline-formula><tex-math id="M6">\begin{document}$ {\omega _{\rm{I}}} = 46{{\rm{e}}^{0.0045{\omega _{{\rm{M0}}}}}}$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20200821_M6.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20200821_M6.png"/></alternatives></inline-formula>. Although increasing the initial rotation excitation frequency can enhance the rotation frequency of the inner tube, as the initial rotation frequency of the middle tube increases, the axial performance of the inner tube is degraded and the unstable oscillations is aggravated. At the same time, the stability of the axial oscillation of the middle tube is related to the frequency of the initial rotational excitation applied to it. Too high an initial rotational frequency will not only increase the off-axis rocking motion distance, resulting in a degradation in axial oscillation performance, but also the rotation loss will increase as the initial rotation frequency increases. Therefore, a reasonable control of the amplitude of the initial rotation frequency is the key to designing a low-loss TWCNTs screwing oscillator.

Molecular dynamic simulation of defect-driven rotary system based on a triple-walled carbon nanotube and graphene

ABSTRACTIn this paper, a nanoscale rotary system, composed of graphene substrate and triple-walled nanotube driven by defect effect, is proposed. Its rotational properties, as well as the influence of temperature, defect location and chiral combination of carbon nanotube, are systematically investigated using molecular dynamic simulations. It is found that the rotation of the nanotubes is driven by the defects placed on the graphene with a stable rotation frequency, and that the source of energy for the rotary system is originated from the unbalanced atomic vibration on graphene near carbon nanotubes. The results show that the system temperature, the location of the defect and the chiral pair of the carbon nanotubes have effects on the rotor rotation frequency. Based on the analysis of molecular dynamic simulation results, the mechanism of this rotation is studied. The application of nano-rotation system, composed of graphene and triple-walled carbon nanotubes in nanomachines, is prospected.

The critical role of the forest morphology for dry drawability of few-walled carbon nanotubes

Carbon nanotube (CNT) yarns comprise few-walled CNTs (FWCNTs), mainly consisting of double- and triple-walled CNTs, and have several properties which are beneficial for practical bulk-scale carbon devices. These features include high tensile strength, electrical conductivity, thermal conductivity, chemical stability, and environmental tolerance. However, the synthesis window for fabricating CNT yarns with FWCNTs by the dry-spinning method is quite narrow and optimal conditions have yet to be determined. In this study, we fabricated CNT forests mainly comprised of FWCNTs at various synthesis conditions (temperature and time). The drawability of the CNT forests was characterized depending on the synthesis conditions. Our results show that optimum values exist for continuously drawable CNT forests in terms of both their height (>130 μm) and bulk density (>90 mg/cm3) for satisfying enough entanglement force between the CNT bundles. The diameter and number of walls of the CNTs are controlled by the temperature during the formation of catalyst particles because the sizes of catalyst particles are approximately equal to the outer diameter of CNTs. All temperature conditions in the range 350–500 °C, used to form catalyst particles, resulted in a drawable FWCNT forest. These insights will be useful for developing devices based on FWCNT yarns.

Environmental effects, intertube interactions and σ-π bond re-hybridization in bundles of double- and triple-walled carbon nanotubes

In the literature, fine structuring and mixing of the radial breathing mode frequencies (ωRBM) due to intertube interactions (Ωint) for specific inner tubes in free-standing isolated double-walled nanotubes (DWNTs) have been addressed. Questions and arguments related to the Ωint nature and its dependence with the nanotube’s growth processes have also been addressed. Later, studies involving bundled (innermost tubes) and isolated (innermost and middle tubes) of triple-walled nanotubes (TWNTs) for diameters between 0.5 and 1.7 nm found no ωRBM fine structuring or mixing but suggested that the Ωint depends on the tube’s metallicity. Here, Raman Spectroscopy is combined with transmission electron microscopy (TEM) to show that for bundled DWNTs and TWNTs measured in a broad diameter range (0.5≤dt≤2.8 nm) three effects seem to be fundamental to explain the ωRBM behavior of their constituent tubes: interactions with the external environment, metallicity-independent Ωint and curvature effects due to σ-π bonds re-hybridization. Our results display no evidence of ωRBM mixing but show that Ωint has no apparent dependence with the growth process and that Ωint has the same nature of the tube interactions with the environment. The manuscript also discusses the thus far elusive TWNT outermost tubes ωRBM.

Axial and torsional buckling analysis of single- and multi-walled carbon nanotubes: finite element comparison between armchair and zigzag types

The present work deals with the axial and torsional buckling analysis and design of carbon nanotubes (CNTs) by finite element. Computer-aided design, computer-aided engineering simulation, and finite element modeling are applied for the calculation of axial and torsional displacement and von Mises stresses. The smallest diameter of single-walled, double-walled, and multi-walled carbon nanotubes have been selected to survey armchair and zigzag types of CNTs. Nanotube diameters, covalent and van der Waals bonding, interlayer spacing, and chirality is considered in nanotubes construction based on actual dimensions. This paper illustrates that armchair-type nanotube is more resistant than zigzag-type against axial buckling for single-walled carbon nanotubes, whereas, in the case of torsional loading, zigzag-type show superior performance against buckling. By increasing the diameter and number of layers, due to van der Waals interaction, elastic buckling properties of nanotubes can be improved significantly. Data analysis for double-walled carbon nanotubes has shown that armchair-type is a better choice under combined loading, whereas, in the meantime, zigzag-type for triple-walled carbon nanotubes is preferred in the comparative analysis under combined loading. The results demonstrate the vital role of covalent intermolecular forces for single-walled nanotubes and van der Waals interlayer interactions for multi-walled nanotubes under buckling loading. The present study investigated the effect of covalent and van der Waals bonding for small diameter nanotubes.