Double-walled Carbon Nanotubes Research Articles

Anti-Stokes Raman Scattering of Single Carbyne Chains.

We investigate the anti-Stokes Raman scattering of single carbyne chains confined inside double-walled carbon nanotubes. Individual chains are identified using tip-enhanced Raman scattering (TERS) and heated by resonant excitation with varying laser powers. We study the temperature dependence of carbyne's Raman spectrum and quantify the laser-induced heating based on the anti-Stokes/Stokes ratio. Due to its molecular size and its large Raman cross section, carbyne holds great promise for local temperature monitoring, with potential applications ranging from nanoelectronics to biology.

Effect of the Nanotube Radius and the Volume Fraction on the Mechanical Properties of Carbon Nanotube-Reinforced Aluminum Metal Matrix Composites.

By using the advantages of carbon nanotubes (CNTs), such as their excellent mechanical properties and low density, CNT-reinforced metal matrix composites (MMCs) are expected to overcome the limitations of conventional metal materials, i.e., their high density and low ductility. To understand the behavior of composite materials, it is necessary to observe the behavior at the molecular level and to understand the effect of various factors, such as the radius and content of CNTs. Therefore, in this study, the effect of the CNT radius and content on the mechanical properties of CNT-Al composites was observed using a series of molecular dynamics simulations, particularly focusing on MMCs with a high CNT content and large CNT diameter. The mechanical properties, such as the strength and stiffness, were increased with an increasing CNT radius. As the CNT content increased, the strength and stiffness increased; however, the fracture strain was not affected. The behavior of double-walled carbon nanotubes (DWNTs) and single-walled carbon nanotubes (SWNTs) was compared through the decomposition of the stress–strain curve and observations of the atomic stress field. The fracture strain increased significantly for SWNT-Al as the tensile force was applied in the axial direction of the armchair CNTs. In the case of DWNTs, an early failure was initiated at the inner CNTs. In addition, the change in the elastic modulus according to the CNT content was predicted using the modified rule of mixture. This study is expected to be useful for the design and development of high-performance MMCs reinforced by CNTs.

Synthesis of carboxymethyl Xanthan/ double-walled carbon nanotube hybrid hydrogel nanocomposite for transdermal release of drug

ABSTRACT The inclusion of double-walled carbon nanotubes in carboxymethyl xanthan-based hydrogels was developed in order to improve both mechanical and drug release (diclofenac) properties of these nanocomposites for potential application in the biomedical field. The synthesis of carboxymethyl xanthan was carried out by an esterification reaction between xanthan gum and monochloroacetic acid, and the grafting was confirmed by FTIR analysis. The obtained carboxymethyl derivatives exhibited higher hydrophilicity degrees of substitution compared to the native xanthan gum. The nanocomposites prepared using either raw or modified xanthan gum were characterized in terms of physical properties, and we evidenced both an increase in viscoelasticity by one order of magnitude and an improved distribution of the nanotubes within the hydrogel matrix in the case of the carboxymethyl xanthan. The trapping efficiency of diclofenac was improved by the addition of the nanotubes, reaching up to 74 wt %. While the nanotubes also allowed a slower release of the molecule. An in-vitro study was carried out to ensure that the CNTs grafted onto the modified CMX were not released during the diffusion of the active ingredient.

Photothermal synthesis of confined carbyne

The recent materialization carbyne confined to double-walled carbon nanotubes represents a major breakthrough in materials science but the control of its properties remains a major challenge. Here, localized photothermal heating through laser annealing and the possibility to perform Raman spectroscopy in-situ allow fabricating confined carbyne with tailored properties. Transmission electron microscopy shows the confined carbyne can reach about 10 nm in length. Evident interaction between the nanotubes and the confined carbyne alters the tube's diameter. Furthermore, the mechanism to tailor the properties of the confined carbyne could be associated to its corresponding Raman mode. The evolution of the synthesis constricted to the tube under increasing laser power can be monitored step by step from the moment the growth starts until a knock-off threshold is reached. Photothermal annealing represents a real possibility to synthesize carbyne confined to single-chirality carbon nanotubes, which is not entirely feasible otherwise.

The stability loss of a locally curved double-walled carbon nanotube in visco-elastic matrix

In the current study, stability loss investigation is carried out for a viscoelastic medium containing a double-walled carbon nanotube with local curvature. This research has been carried out using the three dimensional linearized stability theory (TDLTS) within the framework of the piecewise-homogeneous body model. In this case, it is supposed that the carbon nanotube (CNT) has an insignificant initial local defect, and the increase of this defect with the flow of time is examined. Moreover, it is accepted as the criterion for determining the loss of stability that local curvature of the CNT starts to grow indefinitely. The values of the critical time and critical force are obtained from this criterion. In addition, van der Waals forces between the inner surface of the outer tube of the CNT and the outer surface of the inner tube of the CNT were considered. The fractional-exponential Rabotnov operator defines the composite material’s viscoelasticity properties. It is expected that the results obtained from this paper may be a useful guide in applications related to exhibiting the mechanical behavior of the composite material under consideration. Therefore, the effects of viscoelasticity towards composite materials containing a locally curved DWCNT and the limits to be considered in the production of this material are obtained.

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.

(Invited) Ultrasonication-Induced Inner Shell Extraction from Double‐Wall Carbon Nanotubes: Characterisation By Ultracentrifugation and in Situ Raman and Fluorescence-Excitation Spectroscopy

We show that ultrasonication extracts inner tubes from double-wall carbon nanotubes (DWCNT), and characterize the process by density gradient ultracentrifugation (DGU) combined with in situ spectroscopic characterization in the density gradient. Our observations also cast new light on the question whether or not the inner tubes of DWCNTs fluoresce, which has been the subject of a long-standing debate, even though single‐DWCNT experiments have already shown drastic PL‐quenching for the inner CNT [1]. Indeed, in previous studies to characterise the PL from DWCNTs, they were typically solubilised using sonication, while here we see that upon sonication, the extraction of the inner tubes from the DWCNTs leads to much more, efficiently fluorescing SWCNTs. First, the DWCNTs were purified from SWCNTs and bundles using density gradient ultracentrifugation (DGU). Then, sonication is applied, after which the extracted inner tubes were separated from the DWCNTs by DGU and characterised by in situ resonant Raman and PL‐spectroscopy as a function of height in the centrifuge tube [2]. These subsequent in situ DGU experiments unambiguously prove the extraction of inner SWCNTs from DWCNTs, even by very brief sonication, and sonication-time-dependent measurements show that the process quickly saturates.[1] D. Levshov, R. Parret, H.-N. Tran, T. Michel, T.T. Cao, V.C. Nguyen, R. Arenal, V.N. Popov, S.B. Rochal, J.-L. Sauvajol, A.-A. Zahab, M. Paillet, Phys. Rev. B 96, 195410 (2017). [2] S. Cambré, P. Muyshondt, R. Federicci, W. Wenseleers, Nanoscale 7, 20015 (2015).

(Invited) The Moiré Structure of Double Walled Carbon Nanotubes Affects Their Electronic and Vibrational States

Double walled carbon nanotubes (DWCNT) are formed from two concentric single walled carbon nanotubes. They are a one-dimensional moiré system where the coupling strength between the two walls varies greatly depending on the atomic structure of the two tubes. In this talk we discuss the effect of moiré coupling on the electronic and vibrational states of DWCNTs. We focus on the regime of strong moiré coupling and the combination of semiconducting inner and semiconducting outer tube. For such DWCNTs moiré coupling leads to a red-shift of most optical transition energies. The coupling also affects the frequency of the radial breathing mode (RBM), which is an unexpected finding in connection with moiré interaction. We predict a linear correlation between the change in RBM frequency and in optical transition energy. To verify our predictions we will present resonant Raman experiments on DWCNTs sorted by metallic character. We show that the splitting of the RBM frequencies in DWCNT samples is a clear manifestation of the moiré coupling and construct a Kataura plot for the assignment of double walled tubes. Using resonance Raman profiles of the RBM we confirm the correlation between electronic and vibrational shifts. We also discuss the effect of dielectric screening on the Raman intensities. Our work shows how moiré coupling can strongly affect the vibrational in addition to the electronic and optical states of a one-dimensional system.

Carbon nanotube pellicles: imaging results of the first full-field extreme ultraviolet exposures

Extreme ultraviolet (EUV) lithography was recently implemented in high-volume wafer production. Consequently, maximizing yield is gaining importance. One key component to achieving optimal yield is using a pellicle to hold particles out of the focal plane and thereby minimizing the printing of defects. The carbon nanotube (CNT) pellicle is a membrane consisting of a network of CNTs with a demonstrated EUV transmission (EUV-T) of up to 98%. The challenge is balancing the CNT material parameters for optimal performance in the EUV scanner: low probability for particles to pass, low impact on imaging through scattered light, and high durability in the scanner environment, while maintaining high transmission. We report results of the first full-field CNT pellicle exposures on an EUV scanner. We demonstrate handling of the pellicles, without breakage, and provide a first assessment of their imaging behavior. Multiple single- and double-walled uncoated CNT pellicles with EUV-T of up to 97.7% were exposed on the EUV scanner at imec, and minimal impact on the imaging was confirmed. In these exposures, uncoated CNT pellicles that do not yet meet the specifications regarding lifetime were used. Therefore, ongoing developments focus on CNT durability in scanner environments. The presented demonstration proves the value of a CNT-based EUV pellicle solution.

Performance Comparison of Double-Walled Carbon Nanotubes and Active ‎Carbon Derived from Coconut Shells for ‎Naphthalene Adsorption in the Aquatic Solution

یکی از ترکیبات خطرناک برای انسان و محیط‌زیست هیدروکربن‌های آروماتیک چند حلقه‌ای PAHs است که نفتالین، مقدم‌ترین هیدروکربن آروماتیک با دو حلقه بنزنی است. این ترکیبات سرطان‌زا و سمی هستند و باعث کم‌خونی و آسیب به شبکیه چشم نیز می‌شوند و برای گیاهان و آبزیان نیز سمی هستند. این ترکیبات خطرناک به‌عنوان سه آلاینده‌ای به‌شماره می‌روند که حذف آنها از سوی سازمان بهداشت جهانی در اولویت قرار گرفته است، در عین حال این ترکیبات توسط روش‌های بیولوژیکی به سختی حذف می‌شوند. این پژوهش در شرایط آزمایشگاهی ناپیوسته انجام شده که در آن تأثیر پارامترهایی مانند زمان ماند 15، 30، 45، 60، 90 و 120 دقیقه، غلظت نانولوله کربنی چند دیواره و کربن فعال حاصل از پوست نارگیل 1/0، 25/0، 5/0، 75/0، 1 و 2 گرم در لیتر، غلظت محلول نفتالین 1، 5، 10، 15، 20، 50 و 100 میلی‌گرم در لیتر و pH معادل 3، 4، 5، 6، 7 و 8 در غلظت 10 میلی‌گرم در لیتر محلول نفتالین در حذف نفتالین بررسی شد. داده‌های تجربی تعادل جذب با مدل‌های مختلف ایزوترم جذب لانگمیر و فروندلیچ ارزیابی و همراه با سینتیک جذب از طریق مقایسه ضریب تبیین R2 بررسی شد و به وسیله نرم‌افزار Excel تحلیل شد. حداکثر جذب سطحی نفتالین بر روی هر دو جاذب، نانولوله‌های کربنی و کربن فعال حاصل از پوست نارگیل در غلظت اولیه 10 میلی‌گرم در لیتر نفتالین و مقدار دوز جاذب برابر 75/0 گرم در لیتر در pH برابر 7 و زمان مناسب برای دستیابی به حداکثر جذب نفتالین و حالت تعادل90 دقیقه است. مکانیسم جذب در هر دو جاذب ایزوترم جذب لانگمیر سازگار بوده و ضریب تبیین آنها به‌ترتیب در نانولوله کربنی برابر با 9589/0R²= و در کربن فعال حاصل از پوست نارگیل 9319/0R²= بود و هر دو جاذب از سنتیک جذب درجه دوم تبعیت می‌کنند. نانولوله‌های کربنی چند جداره و کربن فعال حاصل از پوست نارگیل به‌دلیل اندازه کوچک، سطح مقطع زیاد در نتیجه واکنش‌پذیری بسیار زیاد، به‌عنوان جاذب برای حذف نفتالین از آب کارایی زیادی دارد و نانولوله کربنی چند جداره جذب بیشترین نسبت به کربن فعال حاصل از پوست نارگیل دارد، بنابراین به‌دلیل مقرون به‌صرفه‌بودن و در دسترس بودن آن به‌عنوان جاذب بهتری مورد توجه قرار گرفته است.

Electrical Conductivity of Multiwall Carbon Nanotube Bundles Contacting with Metal Electrodes by Nano Manipulators inside SEM.

Determining the metallicity and semiconductivity of a multi-walled carbon nanotube (MWCNT) bundle plays a particularly vital role in its interconnection with the metal electrode of an integrated circuit. In this paper, an effective method is proposed to determine the electrical transport properties of an MWCNT bundle using a current–voltage characteristic curve during its electrical breakdown. We established the reliable electrical nanoscale contact between the MWCNT bundle and metal electrode using a robotic manipulation system under scanning electron microscope (SEM) vacuum conditions. The experimental results show that the current–voltage curve appears as saw-tooth-like current changes including up and down steps, which signify the conductance and breakdown of carbon shells in the MWCNT bundle, respectively. Additionally, the power law nonlinear behavior of the current–voltage curve indicates that the MWCNT bundle is semiconducting. The molecular dynamics simulation explains that the electron transport between the inner carbon shells, between the outermost carbon shells and gold metal electrode and between the outermost carbons shells of two adjacent individual three-walled carbon nanotubes (TWCNTs) is through their radial deformation. Density functional theory (DFT) calculations elucidate the electron transport mechanism between the gold surface and double-wall carbon nanotube (DWCNT) and between the inner and outermost carbon shells of DWCNT using the charge density difference, electrostatic potential and partial density of states.

Carbon-nanotube Nanomotor Driven by Graphene Origami

Experiments have shown that graphene origami (GORI) can be formed by compressing a folio graphene ribbon. In this study, the GORI is introduced to a rotary nanomotor built from a double-walled carbon nanotube. By placing several cantilevered GORI around the long inner tube (rotor) of the nanomotor with their tips toward the rotor, the nonbonding interaction between the tips and the rotor becomes strong when their distance is less than 1 nm. Rotationally symmetrical layout of the GORI tends to induce nonzero unidirectional torque on the rotor. Thereout, the rotor is accelerated to rotate until a stable rotational frequency (SRF) is reached on the condition that the stators (short outer tubes) applying equal but opposite torque on the rotor. The molecular-dynamics simulation approach is adopted to verify the procedure of the proposed rotary nanomotor. Conclusions are drawn for fabrication of the present rotary nanomotor.

A novel rotation transmission nano-system based on Carbon@Boron-Nitride@Carbon heterogeneous nanotubes: A molecular dynamics study

A novel rotation transmission nano-system (RTS) model built from heterogeneous triple-walled nanotubes (TWNTs) is proposed to achieve a specific stable speed output and its transmission performance is investigated using the molecular dynamics (MD) method. In the proposed heterogeneous RTS, the inner carbon nanotube (CNT) acts as a rotor, the middle boron nitride tube (BNNT) acts as a motor, and the outer CNT acts as a stator. The transmission between the motor and the rotor is completed by the interlayer van der Waals effects and the end effects. The MD simulation results show that heterogeneous TWNTs RTS could work stably in an environmental temperature range of 100 K to 600 K. Constraint conditions have a significant influence on the transmission performance of the rotors, and when the motor and rotor are both free, the RTS has the best transmission behavior. It can also be found that RTS under different working conditions is accompanied by different temperature differences between the motor and rotor during service. Compared with the traditional RTS consisting of an independent single-walled carbon nanotube (SWCNT) (worked as motor) and a group of coaxially arranged double-walled carbon nanotubes (DWCNTs) (worked as rotor and stator), the proposed RTS is easier to control and the rotors’ output signal is tunable in a wider temperature range.

Complex Geometry Strain Sensors Based on 3D Printed Nanocomposites: Spring, Three-Column Device and Footstep-Sensing Platform.

Electromechanical sensing devices, based on resins doped with carbon nanotubes, were developed by digital light processing (DLP) 3D printing technology in order to increase design freedom and identify new future and innovative applications. The analysis of electromechanical properties was carried out on specific sensors manufactured by DLP 3D printing technology with complex geometries: a spring, a three-column device and a footstep-sensing platform based on the three-column device. All of them show a great sensitivity of the measured electrical resistance to the applied load and high cyclic reproducibility, demonstrating their versatility and applicability to be implemented in numerous items in our daily lives or in industrial devices. Different types of carbon nanotubes—single-walled, double-walled and multi-walled CNTs (SWCNTs, DWCNTs, MWCNTs)—were used to evaluate the effect of their morphology on electrical and electromechanical performance. SWCNT- and DWCNT-doped nanocomposites presented a higher Tg compared with MWCNT-doped nanocomposites due to a lower UV light shielding effect. This phenomenon also justifies the decrease of nanocomposite Tg with the increase of CNT content in every case. The electromechanical analysis reveals that SWCNT- and DWCNT-doped nanocomposites show a higher electromechanical performance than nanocomposites doped with MWCNTs, with a slight increment of strain sensitivity in tensile conditions, but also a significant strain sensitivity gain at bending conditions.

Controlled Removal of Surfactants from Double-Walled Carbon Nanotubes for Stronger p-Doping Effect and Its Demonstration in Perovskite Solar Cells.

Double-walled carbon nanotubes (DWNTs) have shown potential as promising alternatives to conventional transparent electrodes owing to their solution processability as well as high conductivity and transparency. However, their DC to optical conductivity ratio is limited by the surrounding surfactants that prevent the p-doping of the DWNTs. To maximize the doping effectiveness, the surfactants are removed from the DWNTs, with negligible damage to the nanotubes, by calcination in an Ar atmosphere. The effective removal of the surfactants is characterized by various analyses, and the results show that the optimal calcination temperature is 400°C. The conductivity of the DWNTs films improves when doped by triflic acid. While the conductivity increase of the surfactants-wrapped DWNT films is 31.9%, the conductivity increase of the surfactants-removed DWNT is found to be 59.7%. Using the surfactants-removed, p-doped, solution-processed transparent electrodes, inverted-type perovskite solar cells are fabricated, resulting in a power conversion efficiency of 17.7% without hysteresis. This work advances the application of DWNTs in transparent conductors, as the efficiency obtained is the highest value achieved to date for carbon nanotube electrode-based perovskite solar cells and solution-processable transparent electrode-based solar cells.

Influence of cation size on the thermoelectric behavior of salt-doped organic nanocomposite thin films

Developing and understanding novel doping strategies for thermoelectric materials is imperative to efficiently convert waste into a useful voltage. One such method for improving the power factor of polymer nanocomposites is through salt doping. The cation size of a monovalent salt dopant was varied in a layer-by-layer (LbL)-assembled film composed of poly(diallyldimethylammonium chloride) (PDDA) and double-walled carbon nanotubes (DWNTs) stabilized by poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) [PEDOT:PSS]. Doping a 20 bilayer PDDA/DWNT-PEDOT:PSS film doped with 3 mmol CsCl yields the maximum power factor of 485 ± 29 μW m−1 K−2. This value was obtained through a five times increase in the electrical conductivity with a minimal decrease in the Seebeck coefficient relative to the undoped film. Cs+ is believed to more heavily dope the carbon nanotube network due to its relatively larger hydrophobicity, while also separating PEDOT from PSS due to charge screening. This study demonstrates the significance of the salt dopant identity, and the insight herein can likely be applied more broadly to improve a variety of organic thermoelectric materials.

Snapshots of the Fragmentation for C70@Single-Walled Carbon Nanotube: Tight-Binding Molecular Dynamics Simulations.

In previously reported experimental studies, a yield of double-walled carbon nanotubes (DWCNTs) at C70@Single-walled carbon nanotubes (SWCNTs) is higher than C60@SWCNTs due to the higher sensitivity to photolysis of the former. From the perspective of pyrolysis dynamics, we would like to understand whether C70@SWCNT is more sensitive to thermal decomposition than C60@SWCNT, and the starting point of DWCNT formation, which can be obtained through the decomposition fragmentation of the nanopeapods, which appears in the early stages. We have studied the fragmentation of C70@SWCNT nanopeapods, using molecular dynamics simulations together with the empirical tight-binding total energy calculation method. We got the snapshots of the fragmentation structure of carbon nano-peapods (CNPs) composed of SWCNT and C70 fullerene molecules and the geometric spatial positioning structure of C70 within the SWCNT as a function of dynamics time (for 2 picoseconds) at the temperatures of 4000 K, 5000 K, and 6000 K. In conclusion, the scenario in which C70@SWCNT transforms to a DWCNT would be followed by the fragmentation of C70, after C70, and the SWCNT have been chemically bonding in the early stages. The relative stability of fullerenes in CNPs could be reversed, compared to the ranking of the relative stability of the encapsulated molecules themselves.

Vibrational and Photoluminescence Properties of Composites Based on Double-Walled Carbon Nanotubes, Poly(o-phenylenediamine) and Poly(ethylene oxide).

Chemical polymerization of o-phenylenediamine (OPD) in the presence of poly(ethylene oxide), double-wall carbon nanotubes (DWNTs) and ferric chloride is carried out in order to obtain composites based on the poly(o-phenylenediamine)-poly(ethylene oxide) (POPD-PEO) fibres covered and interconnected with DWNTs. Vibrational and photoluminescence properties of these composite materials as well as their morphologies are shown by infrared (IR) spectroscopy, Raman scattering, photoluminescence (PL) and scanning electron microscopy (SEM). An adsorption of DWNTs onto the POPD rods surface in the absence and in the presence of PEO is highlighted by SEM. The vibrational changes reported by Raman scattering and IR spectroscopy prove a covalent functionalization of DWNTs with the macromolecular compound POPD which is doped with FeCl-₄ ions. New hydrogen bonds are generated between POPD covalently functionalized DWNTs and hydroxyl groups of PEO according to IR spectroscopic studies. The two macromolecular compounds, POPD and POPD-PEO, show a complex emission band with maxima at 572 and 566 nm, having a shoulder at 667 nm. A significant change in the profile of the PL bands of POPD and POPD-PEO is induced in the DWNTs presence. We show that DWNTs induce (i) a diminution in the POPD PL band intensity peaked between 525-600 nm simultaneous with the increase in the intensity of the PL band situated in the 600-800 nm spectral range and (ii) an enhancement process of the emission band localized in the 475-800 nm spectral range in the case of POPD-PEO.

Screen-Printed Carbon Electrodes Modified with Double-Walled Carbon Nanotubes Functionalized with Polypyrrole and Their Electrochemical Processes in the Presence of Folic Acid.

In this work, the electrochemical polymerization of pyrrole in the presence of H₃PMo12O40 onto the screen-printed carbon electrodes (SPCE) modified with double-walled carbon nanotubes (DWNTs) is reported. The influence of the pyrrole and H₃PMo12O40 concentration as well as a scan rate used to recording of cyclic voltammograms that describe the electrochemical synthesis of polypyrrole (PPY) onto the DWNTs surface is assessed. Using scanning electron microscopy (SEM) we demonstrate that the electrosynthesis of PPY doped with H₃PMo12O40 heteropolyanions (PPY-PMo12) results in the generation of a globular morphology. Considering the variations induced of DWNTs in the IR and Raman spectra of PPY doped with H₃PMo12O40 heteropolyanions, a functionalization process of carbon nanotubes with macromolecular compound is invoked. According to SEM investigations, DWNTs allow the realization of connections between the globular structures of the macromolecular compound. The changes induced of folic acid (FA) during the oxidation-reduction processes at the interface of the DWNTs functionalized with PPY doped with H₃PMo12O40 heteropolyanions (SPCE-DWNT/PPY-PMo12) with electrolyte solution are reported.

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.