Artykuły w czasopismach: „ZIGZAG TYPE NANOTUBE”

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Дадашян, Л. Х., Р. Р. Трофимов, Н. Н. Конобеева i М. Б. Белоненко. "Предельно короткие импульсы в оптически анизотропной среде, содержащей углеродные нанотрубки с металлической проводимостью". Оптика и спектроскопия 130, nr 12 (2022): 1861. http://dx.doi.org/10.21883/os.2022.12.54092.49-22.

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In this work, we study the interaction of extremely short pulses with a nonlinear anisotropic optical medium with carbon nanotubes (armchair and zigzag type) with metallic conductivity. The dependence of the pulse shape, width, and intensity on the nanotube chirality indices is analyzed. The most appropriate type of carbon nanotubes is substantiated for providing localized propagation of an electromagnetic field in a medium with anisotropic properties.

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Dadashyan L.H., Trofimov R.R., Konobeeva N.N. i Belonenko M.B. "Extremely short pulses in an anisotropic optical medium containing carbon nanotubes with metal conduction". Optics and Spectroscopy 130, nr 12 (2022): 1587. http://dx.doi.org/10.21883/eos.2022.12.55246.49-22.

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In this work, we study the interaction of extremely short pulses with a nonlinear anisotropic optical medium with carbon nanotubes (armchair and zigzag type) with metallic conductivity. The dependence of the pulse shape, width, and intensity on the nanotube chirality indices is analyzed. The most appropriate type of carbon nanotubes is substantiated for providing localized propagation of an electromagnetic field in a medium with anisotropic properties. Keywords: optical anisotropy, extremely short pulse, carbon nanotubes, metallic conduc.

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Malysheva, Lyuba. "Effects of chirality in the electron transmission through step-like potential in zigzag, armchair, and (2m,m) carbon nanotubes". Low Temperature Physics 48, nr 11 (listopad 2022): 907–13. http://dx.doi.org/10.1063/10.0014581.

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We report the one-electron spectrum and eigenstates of infinite achiral and chiral (2 m, m) carbon nanotubes found by using the analytic solution to the Schrödinger equation for the tight-binding Huckel-type Hamiltonian. With the help of matching the wave functions on the interfaces between the regions, where electrons have different site energies, we find and compare the transmission coefficients for zigzag, armchair and chiral nanotubes subjected to the action of an applied step-like potential. The correspondence between the nanotube band structure and the energy dependence of the transmission coefficient is demonstrated. It is shown that the (2 m, m) nanotubes with a medium chiral angle reveal intermediate transport properties as compared with the achiral armchair, and zigzag nanotubes.

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Tomilin O. B., Rodionova E. V., Rodin E.A., Poklonski N. A., Anikeyev I. I. i Ratkevich S. V. "Dependence of the energy of emission molecular orbitals in short open carbon nanotubes on the electric field". Physics of the Solid State 64, nr 3 (2022): 347. http://dx.doi.org/10.21883/pss.2022.03.53191.201.

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On the examples of short open carbon nanotubes of armchair type (n,n), for n=3, 4, and zigzag (n,0), for n=5, 6, 7, the influence of the magnitude and direction of the external constant electric field vector on their field emission properties was studied. It is shown that the deviation of the field vector from the nanotube axis leads to an increase in the field strength to generate electron field emission. Emission orbitals in carbon nanotubes (n,n) found as a result of a new type of conjugation of p-electrons in cylindrical conjugated systems are more sensitive to a change in the direction of the electric field vector compared to emission orbitals in nanotubes (n,0). When the electric field vector deviates from the nanotube axis, the emission orbitals of carbon nanotubes change the less, the larger the nanotube diameter. Keywords: short open carbon nanotubes, field emission, conjugation of p-electrons, emission molecular orbital.

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Ghorbanpour Arani, A., M. Mosayyebi, F. Kolahdouzan, R. Kolahchi i M. Jamali. "Refined zigzag theory for vibration analysis of viscoelastic functionally graded carbon nanotube reinforced composite microplates integrated with piezoelectric layers". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 231, nr 13 (14.09.2016): 2464–78. http://dx.doi.org/10.1177/0954410016667150.

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Damped free vibration of carbon nanotube reinforced composite microplate bounded with piezoelectric sensor and actuator layers are investigated in this study. For the mathematical modeling of sandwich structure, the refined zigzag theory is applied. In addition, to present a realistic model, the material properties of system are supposed as viscoelastic based on Kelvin–Voigt model. Distributions of single-walled carbon nanotubes along the thickness direction of the viscoelastic carbon nanotube reinforced composite microplate are considered as four types of functionally graded distribution patterns. The viscoelastic functionally graded carbon nanotube reinforced composite microplate subjected to electromagnetic field is embedded in an orthotropic visco-Pasternak foundation. Hamilton’s principle is employed to establish the equations of motion. In order to calculate the frequency and damping ratio of sandwich plate, boundary condition of plate is assumed as simply-supported and an exact solution is used. The effects of some significant parameters such as damping coefficient of viscoelastic plates, volume fraction of carbon nanotubes, different types of functionally graded distributions of carbon nanotubes, magnetic field, and external voltage on the damped free vibration of system are investigated. Results clarify that considering viscoelastic property for system to achieve accurate results is essential. Furthermore, the effects of volume fraction and distribution type of carbon nanotubes are remarkable on the vibration of sandwich plate. In addition, electric and magnetic fields are considerable parameters to control the behavior of viscoelastic carbon nanotube reinforced composite microplate. It is hoped that the results of this study could be applied in design of nano/micromechanical sensor and actuator systems.

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Okuyama, Rin, Wataru Izumida i Mikio Eto. "Topology in single-wall carbon nanotube of zigzag and armchair type". Journal of Physics: Conference Series 969 (marzec 2018): 012137. http://dx.doi.org/10.1088/1742-6596/969/1/012137.

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Kusunoki, Michiko, Toshiyuki Suzuki i Chizuru Honjo. "Selective Growth of Zigzag-type Carbon Nanotube by Surface Decomposition of SiC". Materia Japan 42, nr 12 (2003): 900. http://dx.doi.org/10.2320/materia.42.900.

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Zhou, Xin, Haifang Cai, Chunwei Hu, Jiao Shi, Zongli Li i Kun Cai. "Analogous Diamondene Nanotube Structure Prediction Based on Molecular Dynamics and First-Principle Calculations". Nanomaterials 10, nr 5 (28.04.2020): 846. http://dx.doi.org/10.3390/nano10050846.

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A concentric twin tube (CTT) can be built by placing a carbon nanotube (CNT) in another identical CNT. Different from diamondene nanotubes, a stable CTT has no inter-shell covalent bond. As a prestressed double-walled nanotube, CTT has a lower structural stability at a finite temperature. According to the molecular dynamics and first-principle calculations, (a) CTTs have three types of relaxed configurations. In a type III CTT, the inner tube buckles to produce a V-shaped cross-section, and the outer tube may be convex or concave. (b) The minimal radii of relaxed zigzag and armchair CTTs with concave outer tubes were found. (c) After relaxation, the circumferences and areas of the two tubes in a type III CTT are different from those of the corresponding ideal CNT. The area change rate (A-CR) and circumference change rate (C-CR) of the outer tube are the first-order Gaussian function of the radius of the ideal CNT (which forms the CTT), and tends to be 73.3% of A-CR or 95.3% of C-CR, respectively. For the inner tube of a CTT, the A-CR is between 29.3% and 37.0%, and the C-CR is close to 95.8%. (d) The temperature slightly influences the findings given above.

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Zhao, Yipeng, Huamin Hu i Gang Ouyang. "Optimizing the photovoltaic effect in one-dimensional single-wall carbon nanotube @ MoS₂ van der Waals heteronanotubes". Journal of Applied Physics 132, nr 23 (21.12.2022): 234304. http://dx.doi.org/10.1063/5.0124128.

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One-dimensional single-wall carbon nanotube (1D-SWCNT)@MoS2 van der Waals (vdW) heteronanotubes (HNTs) have inherited extensive attention due to their fascinating properties and increasing mature methods. However, the curvature and chirality dependence of photovoltaic properties in such kind of 1D systems remain unclear. In our work, we explore the electronic and photoelectric properties of 1D-SWCNT@MoS2 vdW HNTs based on the atomic-bond-relaxation approach and the modified detailed balance principle by quantization of band offset and carrier transport behaviors. We find that the optimized power conversion efficiency (PCE) of zigzag-SWCNT@ zigzag-MoS2 HNTs is ∼5.3% at the diameter of 3.1 nm, while that of zigzag-SWCNT@ armchair-MoS2 HNTs is ∼4.9% at 3.3 nm. Moreover, the PCE can be enhanced further by intercalating h-BN layers at the interface of 1D-vdW HNTs. Our results suggest that 1D-SWCNT@MoS2 HNTs can be served as promising building blocks for the new type of photovoltaic devices.

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Sekiguchi, Ryuta, Kei Takahashi, Jun Kawakami, Atsushi Sakai, Hiroshi Ikeda, Aya Ishikawa, Kazuchika Ohta i Shunji Ito. "Preparation of a Cyclic Polyphenylene Array for a Zigzag-Type Carbon Nanotube Segment". Journal of Organic Chemistry 80, nr 10 (6.05.2015): 5092–110. http://dx.doi.org/10.1021/acs.joc.5b00485.

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Glukhova O. E., Slepchenkov M. M. i Kolesnichenko P. A. "Tunneling current between structural elements of thin graphene/nanotube films". Physics of the Solid State 64, nr 14 (2022): 2450. http://dx.doi.org/10.21883/pss.2022.14.54349.180.

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Based on the constructed atomistic models of graphene/nanotube films with different numbers of nanotubes in supercells, we carried out in silico studies of the regularities of the nonuniform density distribution, which determine the presence of an island structure in such films. As a result of quantum molecular dynamics modeling, it is found that thin tubes of subnanometer diameter are enveloped in graphene sheets, which makes them energetically stable and stable. We also studied tunneling contacts between individual film fragments that are not covalently bound, in particular, between graphene sheets with different topologies of contacting zigzag and armchair edges, depending on the distance between them, and between tubes of different chiralities, including (6,3), (4,4), (6,5), (12,6) and (16,0). It is found that the tunnel contacts of tubes with a semiconductor type of conductivity are characterized by the presence of voltage intervals with a negative differential resistance in the I-V characteristic. Such voltage intervals are not observed at all for tubes with a metallic character of conductivity. The new knowledge obtained is important for assessing the electrical conductivity of such films, two-thirds of which are semiconductor tubes. Keywords: graphene, nanotubes, tunnel contacts.

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Slepchenkov, Michael M., Pavel V. Barkov i Olga E. Glukhova. "Electronic and Electrical Properties of Island-Type Hybrid Structures Based on Bi-Layer Graphene and Chiral Nanotubes: Predictive Analysis by Quantum Simulation Methods". Coatings 13, nr 5 (22.05.2023): 966. http://dx.doi.org/10.3390/coatings13050966.

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Hybrid structures based on graphene and carbon nanotubes (CNTs) are one of the most relevant modern nanomaterials for applications in various fields, including electronics. The variety of topological architectures of graphene/CNT hybrids requires a preliminary study of their physical properties by in silico methods. This paper is devoted to the study of the electronic and electrical properties of graphene/CNT hybrid 2D structures with an island topology using the self-consistent charge density functional-based tight-binding (SCC-DFTB) formalism and the Landauer–Buttiker formalism. The island-type topology is understood as the atomic configuration of a graphene/CNT hybrid film, in which the structural fragments of graphene and nanotubes form “islands” (regions of the atomic structure) with an increased density of carbon atoms. The island-type graphene/CNT hybrid structures are formed by AB-stacked bilayer graphene and (6,3)/(12,8) chiral single-walled carbon nanotubes (SWCNT). The bilayer graphene is located above the nanotube perpendicular to its axis. Based on the binding energy calculations, it is found that the atomistic models of the studied graphene/SWCNT hybrid structures are thermodynamically stable. The peculiarities of the band structure of graphene/SWCNT (6,3) and graphene/SWCNT (12,8) hybrid structures are analyzed. It is shown that the electronic properties of graphene/SWCNT hybrid structures are sensitive to the orientation and size of the graphene layers with respect to the nanotube surface. It is found that an energy gap of ~0.1 eV opens in the band structure of only the graphene/SWCNT (6,3) hybrid structure, in which the graphene layers of the same length are arranged horizontally above the nanotube surface. We revealed the electrical conductivity anisotropy for all considered atomistic models of the graphene/SWCNT (12,8) hybrid structure when bilayer graphene sheets with different sizes along the zigzag and armchair directions are located at an angle with respect to the nanotube surface. The obtained knowledge is important to evaluate the prospects for the potential application of the considered atomic configurations of graphene/SWCNT hybrid structures with island-type topology as connecting conductors and electrodes in electronic devices.

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Niikuni, Hiroaki. "Spectra of Periodic Schrödinger Operators on the Degenerate Zigzag Nanotube with δ Type Vertex Conditions". Integral Equations and Operator Theory 79, nr 4 (31.05.2014): 477–505. http://dx.doi.org/10.1007/s00020-014-2162-9.

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Yengejeh, Sadegh Imani, Andreas Öchsner, Seyedeh Alieh Kazemi i Maksym Rybachuk. "Numerical Analysis of the Structural Stability of Ideal (Defect-Free) and Structurally and Morphologically Degenerated Homogeneous, Linearly- and Angle-Adjoined Nanotubes and Cylindrical Fullerenes Under Axial Loading Using Finite Element Method". International Journal of Applied Mechanics 10, nr 09 (listopad 2018): 1850100. http://dx.doi.org/10.1142/s1758825118501004.

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We report on the structural stability of ideal (defect-free) and structurally and morphologically degenerate carbon nanotubes and nanotube junction systems under axial loading based on the finite element method. We estimated the values for critical buckling load for uncapped and capped single-walled carbon nanotubes (SWCNTs) and linear and angle-adjoined SWCNT heterojunctions in ideal and structurally degenerate systems containing single-, double-, triple-, pinhole- and pentagon–heptagon (i.e., 5–7) structural defects and also containing a substitutional nitrogen (N) atom inclusion under compressive loading. Absolute atomic vacancy (defect) concentration in studied SWCNTs models was assumed to be nil for ideal systems, and was up to 3.0 at.% for structurally and morphologically degenerate systems. It was found that all types of structural defects and the morphological N-defect had reduced the load carrying capacity and mechanical strength in all SWCNT systems studied. The SWCNT models containing physically large vacant sites, such as triple- and pinhole-defects, displayed significantly lower critical load values compared to the systems that contained only a single-, double- or triple-vacancies. In addition, we found that capped SWCNTs performed marginally better in critical load carrying capacity compared to uncapped SWCNT systems. Furthermore, majority of the investigated structures displayed reduced load in SWCNTs with narrower tube widths, proportional to the size and the type of the defect investigated. The effects of chirality, such as zigzag- versus armchair-type, on the structural stability of the investigated SWCNT models were also investigated.

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Khavryuchenko, Oleksiy V., Gilles H. Peslherbe i Frank Hagelberg. "Spin Filter Circuit Design Based on a Finite Single-Walled Carbon Nanotube of the Zigzag Type". Journal of Physical Chemistry C 119, nr 7 (9.02.2015): 3740–45. http://dx.doi.org/10.1021/jp5095799.

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Глухова, О. Е., М. М. Слепченков i П. А. Колесниченко. "Туннельный ток между структурными элементами тонких графен/нанотрубных пленок". Физика твердого тела 63, nr 12 (2021): 2198. http://dx.doi.org/10.21883/ftt.2021.12.51684.180.

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Based on the constructed atomistic models of graphene/nanotube films with different numbers of nanotubes in supercells, we carried out in silico studies of the regularities of the nonuniform density distribution, which determine the presence of an island structure in such films. As a result of quantum molecular dynamics modeling, it is found that thin tubes of subnanometer diameter are enveloped in graphene sheets, which makes them energetically stable and stable. We also studied tunneling contacts between individual film fragments that are not covalently bound, in particular, between graphene sheets with different topologies of contacting zigzag and armchair edges, depending on the distance between them, and between tubes of different chiralities, including (6,3), (4,4), (6,5), (12,6) and (16,0). It is found that the tunnel contacts of tubes with a semiconductor type of conductivity are characterized by the presence of voltage intervals with a negative differential resistance in the I – V characteristic. Such voltage intervals are not observed at all for tubes with a metallic character of conductivity. The new knowledge obtained is important for assessing the electrical conductivity of such films, two-thirds of which are semiconductor tubes.

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Mohammadi, Mohsen Doust, i Hewa Y. Abdullah. "DFT Study for Adsorbing of Bromine Monochloride onto BNNT (5,5), BNNT (7,0), BC₂NNT (5,5), and BC₂NNT (7,0)". Journal of Computational Biophysics and Chemistry 20, nr 08 (24.11.2021): 765–83. http://dx.doi.org/10.1142/s2737416521500472.

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The study of intermolecular interactions is of great importance. This study attempted to quantitatively examine the interactions between bromine monochloride (BrCl) with pristine boron nitride nanotube (BNNT) armchair (5,5) and zigzag (7,0) as well as armchair (5,5) BC2NNT and zigzag (7,0) BC2NNT in vacuum. Quantum mechanical studies of such systems are possible in the density functional theory (DFT) framework. For this purpose, various functionals, such as B3LYP-D3, [Formula: see text]B97XD, and M062X, have been used. One of the most suitable basis functionals for the systems studied in this research is 6-311G (d), which has been used in both optimization calculations and calculations related to wave function analyses. The main part of this work is the study of various analyses that reveal the nature of the intermolecular interactions between the two components introduced above. The results of conceptual DFT, natural bond orbital, non-covalent interactions, and quantum theory of atoms in molecules (QTAIM) were consistent and in favor of physical adsorption in all systems. Gallium had more adsorption energy than other dopants. The HOMO–LUMO energy gaps were as follows: BNNT (5,5): 10.296, BNNT (7,0): 9.015, BC2NNT (5,5): 7.022, and BC2NNT (7,0): 5.979[Formula: see text]eV at B3LYP-D3/6-311G (d) model chemistry. The strongest interaction is related to the BC2NNT (7,0)/BrCl cluster: [Formula: see text][Formula: see text]eV. The results of QTAIM and NCI analysis identified the intermolecular interactions of the type of strong van der Waals interaction for these nanotubes. The sensitivity of the adsorption increased when a gas molecule interacted with carbon-doped BNNT, and the change in the frontier orbital gap could be used to design nanosensors to detect BrCl gas.

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Elmahdy, Atef, Hayam Taha, Mohamed Kamel i Menna Tarek. "Mechanical bending effects on hydrogen storage of Ni decorated (8, 0) boron nitride nanotube : DFT study". JOURNAL OF ADVANCES IN PHYSICS 16, nr 1 (10.08.2019): 299–325. http://dx.doi.org/10.24297/jap.v16i1.8389.

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The influence of mechanical bending to tuning the hydrogen storage of Ni-functionalized of zigzag type of boron nitride nanotubes (BNNTs) has been investigated using density functional theory (DFT) with reference to the ultimate targets of the US Department of Energy (DOE). Single Ni atoms prefer to bind strongly at the axial bridge site of BN nanotube, and each Ni atom bound on BNNT may adsorb up to five, H2 molecules, with average adsorption energies per hydrogen molecule of )-1.622,-0.527 eV( for the undeformed B40N40-? = 0 , ) -1.62 , 0-0.308 eV( for the deformed B40N40-? = 15, ) -1.589, -0.310 eV( for the deformed B40N40-? = 30, and ) -1.368- -0.323 eV( for the deformed B40N40-? = 45 nanotubes respectively. with the H-H bonds between H2 molecules significantly elongated. The curvature attributed to the bending angle has effect on average adsorption energies per H2 molecule. With no metal clustering, the system gravimetric capacities are expected to be as large as 5.691 wt % for 5H2 Ni B40N40-? = 0, 15, 30, 45. While the desorption activation barriers of the complexes nH2 + Ni B40N40-? = 0 (n = 1-4) are outside the (DOE) domain (-0.2 to -0.6 eV), the complexes nH2 + Ni- B40N40-? = 0 (n = 5) is inside this domain. For nH2 + Ni- B40N40-? = 15, 30, 45 with (n = 1-2) are outside the (DOE) domain, the complexes nH2 + Ni- B40N40-? = 15, 30, 45 with (n = 3-5) are inside this domain. The hydrogen storage of the irreversible 4H2+ Ni- B40N40-? = 0, 2H2+ Ni- B40N40-? = 15, 30, 45 and reversible 5H2+ Ni- B40N40-? = 0, 3H2+ Ni- B40N40-? = 15, 30, 45 interactions are characterized in terms of density of states, pairwise and non-pairwise additivity, infrared, Raman, electrophilicity and molecular electrostatic potentials. Our calculations expect that 5H2- Ni- B40N40-j = 0, 15, 30, 45 complexes are promising hydrogen storage candidates.

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Wu, Jianbao, Liyuan Jiang, Xiaoyi Li i Zhixiang Yin. "C2O Nanotubes with Negative Strain Energies and Improvements of Thermoelectric Properties via N-Doping Predicted from First-Principle Calculations". Crystals 13, nr 7 (13.07.2023): 1097. http://dx.doi.org/10.3390/cryst13071097.

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In this study, the geometric structure, strain energy, and electronic properties of armchair C2O nanotubes (A_C2ONTs(n,n)) and zigzag C2O nanotubes (Z_C2ONTs(n,0)) are studied in detail. The results show that these nanotubes behave as special shapes; the section of Z_C2ONTs(n,0) along the axial direction is an n-edge type, and the section tends to be round with an increase in n while the boundary of section along the axial direction for A_C2ONTs(n,n) fluctuates. With an increase in n, the fluctuation disappears gradually, and the section also tends to be round. Compared with C2O nanosheets (g_C2O), C2O nanotubes have similar or even smaller strain energy, when the tube diameter is greater than or equal to 15 Å, the strain energy begins to show a negative value, and the negative value tends to be stable as the pipe diameter increases. Z_C2ONTs start to show negative strain energies from n = 8 and A_C2ONTs from n = 12, indicating their higher stabilities relative to the g_C2O sheets. The calculation of the electronic band structure shows that Z_C2ONTs are an indirect band gap semiconductor, and A_C2ONT is a direct band gap semiconductor. The band gap value of Z_C2ONTs first increases and then stabilizes with the diameters of the nanotubes, and the band gap value of A_C2ONTs decreases with the increase in the nanotubes and tends to the band gap value of the g_C2O sheet. In addition, the electronic properties and thermoelectric properties of C2ONTs(n=4,6,8) before and after N-doping were also studied. We found that N-doping changed the electronic and thermoelectric properties of C2ONTs. It reduced the nanotube band gap value and significantly improved the thermoelectric figures of merit of Z_C2ONTs(n=4,6,8) and A_C2ONT(4,4), which comprised an effective strategy to improve the thermoelectric figure of merit of nanotubes. The results showed that the C2ONTs had potential as thermoelectric materials after N-doping, which provided important guidance for designing low-dimensional g_C2O nanostructures.

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Sergeeva, E. S. "Dependence of the Elastic Properties of a Single-Walled Carbon Nanotube on its Chirality". Solid State Phenomena 284 (październik 2018): 20–24. http://dx.doi.org/10.4028/www.scientific.net/ssp.284.20.

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Currently, composite materials composed of a matrix and reinforcing components are widely used as a structural material for various engineering devices designed to operate under extreme loads of different types. By modifying a composite with structure-sensitive inclusions, such as a single-wall carbon nanotube, the mechanical properties, especially elastic characteristics, of the resulting material can be significantly improved. The results of investigation of a single-walled carbon nanotubes chirality influence on its elastic properties are presented. Various configurations of nanotubes, such as zigzag and armchair are considered. The dependences of the nanotube bulk modulus and shear modulus of its diameter are shown.

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TSUJI, NAOTO, SHIGEHIRO TAKAJO i HIDEO AOKI. "LARGE MAGNETIC MOMENTS GENERATED FROM LOOP CURRENTS IN CARBON NANOTUBE ATTACHED TO ELECTRODES — A THEORETICAL PICTURE". International Journal of Modern Physics B 21, nr 08n09 (10.04.2007): 1198–206. http://dx.doi.org/10.1142/s021797920704263x.

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Inspired by a recent experiment which has detected a large orbital magnetic moment when electrodes are attached to a carbon nanotube, we study the ballistic transport in metallic carbon nanotubes when a current is injected from electrodes with finite bias voltages with nonequilibrium Green's function method. We reveal, both analytically and numerically, that large loop currents circulating around the tube are induced, which come from a quantum mechanical interference, when the injected electron is resonant with a time-reversed pair of degenerate states inherent in the zigzag and chiral nanotubes. This results in large orbital magnetic moments, making the nanotube a molecular solenoid. The current distribution for various types of tube and the magnetic moment as a function of the bias are displayed.

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Palacios, Jorge A., i Rajamohan Ganesan. "Dynamic response of single-walled carbon nanotubes based on various shell theories". Journal of Reinforced Plastics and Composites 38, nr 9 (15.01.2019): 413–25. http://dx.doi.org/10.1177/0731684418824997.

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Carbon nanotubes are used in several engineering applications because of their superior mechanical properties. Scientific works still need to be carried out, especially on their dynamic response. These studies mainly focus on modal analysis, considering zigzag and armchair nanotubes, and sometimes, varying chirality. However, these works do not present any results on the steady-state responses. Therefore, the objective of this paper is to perform different studies, in terms of the stiffness response, modal analysis and steady-state response of single-walled carbon nanotubes by using a 3D finite-element model of the single-walled carbon nanotube, under different types of boundary conditions, to provide more results in this field. The single-walled carbon nanotube is modeled as a space frame structure by using the Morse potential and as a thin shell model based on various shell theories. A static analysis is performed to compare the stress–strain behavior between the Morse potential and the thin shell model. A parametric study on chirality effects and aspect ratio is also conducted to determine which shell theory is more suitable to model the mechanical behavior of single-walled carbon nanotubes. Finally, the analysis of harmonic response is conducted to describe the steady-state response between both the models.

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Bobenko, Nadezhda, Valeriy Egorushkin i Alexander Ponomarev. "Hysteresis in Heat Capacity of MWCNTs Caused by Interface Behavior". Nanomaterials 12, nr 18 (10.09.2022): 3139. http://dx.doi.org/10.3390/nano12183139.

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The paper is concerned with the study of structural disorder as well as the emergence and causes of heat capacity hysteresis in multiwall carbon nanotubes. The investigation methods are X-ray diffraction analysis, Raman spectroscopy, transmission electron microscopy, and calorimetric tests: thermogravimetric analysis, differential scanning calorimetry, and the thermal relaxation method for heat capacity hysteresis. Multiwall carbon nanotubes are shown to be composed of one or several types of zigzag–armchair domains. The domain structure of nanotube samples is responsible for the generation of uniaxial elastic microstrains and viscoelastic bending strains at domain interfaces. The thermomechanical behavior of interfaces is the chief cause of temperature hysteresis of heat capacity. The number of hystereses corresponds to the number of domain types in the structure, and values of hysteresis are determined by the crystallite size, thermal conductivity, and normal temperature distribution of strain. The found mechanism of heat capacity hysteresis can be helpful in preventing jumps in thermal properties and managing thermal memory in multiwall carbon nanotubes.

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MAJZOOBI, G. H., J. PAYANDEHPEYMAN i Z. BOLBOLI NOJINI. "AN INVESTIGATION INTO THE TORSIONAL BUCKLING OF CARBON NANOTUBES USING MOLECULAR AND STRUCTURAL MECHANICS". International Journal of Nanoscience 10, nr 04n05 (sierpień 2011): 989–93. http://dx.doi.org/10.1142/s0219581x11008666.

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In this work, the critical twist angles of two types of CNTs, zigzag and armchair of different lengths are determined using molecular and structural mechanics. The results show that the torsional buckling modes predicted by the two methods are the same. It is also shown that critical twist angle decreases as CNTs length increases. Structural mechanics underpredicts the critical angle for both armchair and zigzag nonotubes. It is also shown that the critical angle for armchair nanotubes is higher than that for zigzag nanotubes.

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Boroznin, Sergey, Irina Zaporotskova, Natalia Boroznina, Daria Zvonareva, Pavel Zaporotskov i Evgeniya An. "Study of Oxygen Interaction with Surface of Boron-Containing Nanotubes". NBI Technologies, nr 4 (grudzień 2021): 25–33. http://dx.doi.org/10.15688/nbit.jvolsu.2021.4.4.

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Studies of semiconductor carbon nanotubes show that they are extremely sensitive to the chemical environment, and the effects of oxygen drastically change their properties. It has been found that narrow-zone semiconductor carbon tubes can be converted into an apparent metal by such action. Since other types of nanotubes, such as boron-carbon nanotubes of the BC3 type and boron-nitride BN nanotubes, are of great interest, it seems important to investigate whether they are capable of absorbing atomic and molecular oxygen. The study was conducted using the MNDO calculation method within molecular and ion-nested covalent-cyclic cluster models. The results of the study of the interaction of atomic and molecular oxygen with the external surfaces of boron-carbon (BC3), boron-nitride (BN) and boron nanotubes are considered: chair (n, n) and zigzag (n, 0) type. The study was performed by the MNDO method as part of a covalent-cyclic cluster model with embedded ions. Optimal geometry of adsorption complexes is determined and their main electronic and energy properties are described. Boron-carbon nanotubes have been shown to be better oxygen adsorbents than other types of nanotubes considered.

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26

Fülep, Dávid, Ibolya Zsoldos i István László. "Position Sensitivity Study in Molecular Dynamics Simulations of Self-Organized Development of 3D Nanostructures". Materials Science Forum 885 (luty 2017): 216–21. http://dx.doi.org/10.4028/www.scientific.net/msf.885.216.

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The sensitivity of defect free fusion of straight carbon nanotubes from graphene nanoribbons to the position of the nanoribbon edge positions has been investigated. A basic difference between the behavior of armchair and zigzag type nanoribbons was observed. When placing armchair type graphene nanoribbons above each other identical, fitting positions are obtained automatically. Zigzag type graphene nanoribbons, however, must not be placed above each other in identical positions. From the viewpoint of defect-free fusion, according to the MD simulations symmetric on nearly symmetric positions of the ribbon edges are favorable.

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27

Costa Paura, Edson Nunes, Wiliam F. da Cunha, Luiz Fernando Roncaratti, João B. L. Martins, Geraldo M. e Silva i Ricardo Gargano. "CO2 adsorption on single-walled boron nitride nanotubes containing vacancy defects". RSC Advances 5, nr 35 (2015): 27412–20. http://dx.doi.org/10.1039/c4ra17336h.

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Fan, Cheng Wen, Jhih Hua Huang, Chyan Bin Hwu i Yu Yang Liu. "Mechanical Properties of Single-Walled Carbon Nanotubes - A Finite Element Approach". Advanced Materials Research 33-37 (marzec 2008): 937–42. http://dx.doi.org/10.4028/www.scientific.net/amr.33-37.937.

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In this paper, the mechanical properties, such as the axial and radial Young’s moduli, shear moduli, buckling loads and natural frequencies, of single-walled carbon nanotubes, are estimated by a finite element approach. Each carbon nanotube is simulated as a frame-like structure and the primary bonds between two nearest-neighboring atoms are treated as isotropic beam members with a uniform circular cross-section. In the modeling work, the BEAM4 element in commercial code ANSYS is selected to simulate the carbon bonds and the atoms are nodes. As to the input parameters of the BEAM4 element, they are determined via the concept of energy equivalence between molecular dynamics and structural mechanics, and represented in terms of the force constants of the carbon bonds found in molecular mechanics. Based on this modeling concept, finite element models of both armchair and zigzag types of carbon nanotubes with different sizes are established and the mechanical properties of these tubes are then effectively predicted. Most of the computed results which can be compared with existing results show good agreement. Moreover, the effects of tube diameter, length etc., on the mechanical properties are also investigated.

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29

Umeno, Yoshitaka, Atsushi Kubo, Chutian Wang i Hiroyuki Shima. "Diameter-Change-Induced Transition in Buckling Modes of Defective Zigzag Carbon Nanotubes". Nanomaterials 12, nr 15 (29.07.2022): 2617. http://dx.doi.org/10.3390/nano12152617.

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In general, the insertion of Stone-Wales (SW) defects into single-walled carbon nanotubes (SWNTs) reduces the buckling resistance of SWNTs under axial compression. The magnitude of reduction is more noticeable in zigzag-type SWNTs than armchair- or chiral-type SWNTs; however, the relation between the magnitude of reduction and aspect ratio of the zigzag SWNTs remains unclear. This study conducted molecular dynamics (MD) simulation to unveil the buckling performance of zigzag SWNTs exhibiting SW defects with various tube diameter. The dependencies of energetically favorable buckling modes and the SW-defect induced reduction in the critical buckling point on the tube diameter were investigated in a systematic manner. In particular, an approximate expression for the critical buckling force as a function of the tube diameter was formulated based on the MD simulation data.

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30

Chen, Xuan-Wen, Ke-Shan Chu, Rong-Jing Wei, Zhen-Lin Qiu, Chun Tang i Yuan-Zhi Tan. "Phenylene segments of zigzag carbon nanotubes synthesized by metal-mediated dimerization". Chemical Science 13, nr 6 (2022): 1636–40. http://dx.doi.org/10.1039/d1sc05459g.

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Two types of macrocycles were synthesized by gold-mediated dimerization, representing the phenylene cutouts of zigzag carbon nanotubes. These macrocycles showed intriguing optical and supramolecular assembly properties.

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Herrera-Carbajal, Alejandro, Ventura Rodríguez-Lugo, Juan Hernández-Ávila i Ariadna Sánchez-Castillo. "A theoretical study on the electronic, structural and optical properties of armchair, zigzag and chiral silicon–germanium nanotubes". Physical Chemistry Chemical Physics 23, nr 23 (2021): 13075–86. http://dx.doi.org/10.1039/d1cp00519g.

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Infinite size silicon–germanium alloy nanotubes of several types, armchair, zigzag and chiral, are studied by theoretical analysis based on density functional theory as implemented in the SIESTA code.

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32

Barilka, A. G., i R. M. Balabai. "The Flow Behavior of Organic Liquids Inside Carbon Nanotubes". Фізика і хімія твердого тіла 17, nr 3 (15.09.2016): 329–35. http://dx.doi.org/10.15330/pcss.17.3.329-335.

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Within the methods of electron density functional and ab initio pseudopotential, it were obtained the spatial distributions of density of valence and the total energy for migration of water (or methanol) inside carbon nanotubes with clean walls and lined inside with gold atoms. It was found that the mass transfer of methanol through the carbon nanotubes of the zigzag type (15,0) is two orders of magnitude more energy than water.. It was revealed that the mass transfer of water and methanol through carbon nanotubes covered with gold atoms on the inner sides requires an order of magnitude more energy than pure nanotubes.

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Du, Jiguang, Xiyuan Sun i Gang Jiang. "Adsorption of the Ir4 cluster on single-wall carbon nanotubes: the zigzag types are more suitable". RSC Advances 5, nr 74 (2015): 60286–93. http://dx.doi.org/10.1039/c5ra09523a.

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Saenko, Nikita S., i Albert M. Ziatdinov. "Multi-Walled Carbon Nanotubes Synthesized by Methane Pyrolysis: Structure and Magnetic Properties". Solid State Phenomena 213 (marzec 2014): 60–64. http://dx.doi.org/10.4028/www.scientific.net/ssp.213.60.

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The structure and magnetic properties of multi-walled carbon nanotubes produced by catalytic pyrolysis of methane have been investigated by means of mutually complementary physical methods. The average sizes and number of carbon layers forming nanotubes, smearing of the density of states near the Fermi level, degeneracy temperature of gas of extrinsic current carriers, concentrations of localized spins and extrinsic two-dimensional current carriers have been determined. The conclusion has been drawn that ferromagnetic nanoparticles are present in the inner regions of nanotubes, including their tubular cavities. The difference in electronic structure near the Fermi level for carbon nanotubes and ordered graphite has been revealed. The possible reason is that the electronic states near zigzag-type sites of ends as well as edges of linear structural defects in nanotubes make greater contribution to the spectrum than that from similar sites of graphite.

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35

Terauchi, M., M. Tanaka, K. Suzuki, A. Ogino i K. Kimura. "Production of zigzag-type BN nanotubes and BN cones by thermal annealing". Chemical Physics Letters 324, nr 5-6 (lipiec 2000): 359–64. http://dx.doi.org/10.1016/s0009-2614(00)00637-0.

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Özsoy, O., i N. Sünel. "On the electronic band structure of zigzag-type single-walled carbon nanotubes". Czechoslovak Journal of Physics 54, nr 12 (grudzień 2004): 1495–501. http://dx.doi.org/10.1007/s10582-004-1206-9.

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Moaied, Mohammed, i Jisang Hong. "Size-Dependent Critical Temperature and Anomalous Optical Dispersion in Ferromagnetic CrI3 Nanotubes". Nanomaterials 9, nr 2 (26.01.2019): 153. http://dx.doi.org/10.3390/nano9020153.

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Using first principles calculations, we explored the magnetic and optical properties of chromium(III) iodide (CrI3) nanotubes (NTs) by changing their chirality and diameter. Here, we considered six types of NTs: (5,0), (5,5), (7,0), (10,0), (10,10), and (12,0) NTs. We found that both zigzag and armchair NTs had a ferromagnetic ground with a direct band gap, although the band gap was dependent on the chirality and diameter. Using the Monte Carlo simulation, we found that the Curie temperatures (Tc) exhibited chirality and diameter dependence. In zigzag NTs, the larger the tube diameter, the larger the Tc, while it decreased with increasing diameter in the armchair tube. We found that the Tc was almost doubled when the diameter increased two-fold. This finding may guide development of room temperature ferromagnetism in zigzag NTs. We also found that the CrI3 NTs displayed anisotropic optical properties and anomalous optical dispersion in the visible range. Specifically, the (10,0) zigzag NT had a large refractive index of 2 near the infrared region, while it became about 1.4 near blue light wavelengths. We also obtained large reflectivity in the ultraviolet region, which can be utilized for UV protection. Overall, we propose that the CrI3 NTs have multifunctional physical properties for spintronics and optical applications.

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Shailesh, Sarvesh Kumar, B. Tiwari i K. Yadav. "Green Synthesis, Texture, Electron Diffraction, Thermal and Optical Properties of Cobalt Doped Arginine Carbon Nanotubes". Asian Journal of Chemistry 33, nr 5 (2021): 1120–24. http://dx.doi.org/10.14233/ajchem.2021.22684.

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In this work, a simple and viable method of green synthesis of multi-walled cobalt doped arginine carbon nanotubes (CNT’s) by chemical precipitation method using arginine amino acid is reported. The atomic force microscopy confirmed that metal ions present in a branched fashion on the surface of Co-doped arginine CNT’s and the obtained particle with diameter 20 nm well dispersed on the carbon nanotubes. The TEM analysis indicates the interlayer separation between the two adjacent carbon walls is estimated to be about 0.34 nm. The electron diffraction patterns indicate that the tube has nearly identical chirality for all of the concentric graphitic layers, as a zigzag-type MWCNT. The SEM analysis predicted tube like morphology and strain is existed on the surface of the CNTs. The Raman spectra confirmed the armchair (n = 8 to 11) multi-walled nanotubes with this chirality are assigned as a semiconducting type of nanotubes. The thermal property was studied by thermogravimetric analysis, differential thermal analysis and predicted the 27.81 % purity in CNTs.

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39

Zeighampour, Hamid, Yaghoub Tadi Beni i Yaser Kiani. "Electric Field Effects on Buckling Analysis of Boron–Nitride Nanotubes Using Surface Elasticity Theory". International Journal of Structural Stability and Dynamics 20, nr 12 (10.10.2020): 2050137. http://dx.doi.org/10.1142/s0219455420501370.

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In this paper, the axial buckling of boron nitride nanotubes (BNNTs) is investigated by considering the effects of surface and electric field. To achieve this purpose, the surface elasticity theory is exploited and the results are compared with the molecular dynamic simulation in order to validate the accuracy of the applied theory. In the molecular dynamics simulation, the potential between boron and nitride atoms is considered as Tersoff type. The Timoshenko beam theory is adopted to model BNNT. Moreover, two types of zigzag and armchair BNNTs are considered. In this study, the effects of surface, electric field, length, and thickness of BNNT on the critical buckling load are investigated. According to the results, the critical load of zigzag BNNT depends on the electric field. However, the electric field would not affect the critical load of the armchair BNNT. It should be noted that the surface residual tension and surface Lamé’s constants of BNNT have considerable impact on the critical load of BNNT. For lower values of electric field and smaller dimensions of BNNT, the critical load would be more dependent on the surface effect regarding the results. Furthermore, as an efficient non-classical continuum mechanic approach, the surface elasticity theory can fill the potential gap between the classical continuum mechanic and molecular dynamics simulation.

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40

Ghavamian, Ali, i Andreas Öchsner. "Numerical Modeling of the Eigenmodes and Eigenfrequencies of Carbon Nanotubes under the Influence of Defects". Journal of Nano Research 21 (grudzień 2012): 159–64. http://dx.doi.org/10.4028/www.scientific.net/jnanor.21.159.

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Two configurations of perfect single walled carbon nanotubes (armchair and zigzag) were simulated based on the finite element method. Then, three most likely defects (Si-doping, carbon vacancy and perturbation) were introduced to the models to represent defective forms of single walled carbon nanotubes (SWCNTs). Finally, the vibrational properties of perfect and defective carbon nanotubes were evaluated and compared. The results showed that SWCNTs have a natural frequency with a rather high value between 18.69 and 24.01 GHz. In the consideration of the natural frequency of the defective SWCNTs, it was also observed that the existence of any type of defects or irregularities leads to a lower value of natural frequency and vibrational stability. Simple mathematical relations which express the change in natural frequency versus the percentage of the defect were also presented. This can be very useful to realistically estimate the influence of defects of different amounts on the vibrational behavior of carbon nanotubes.

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41

Wu, Jianhua, i Frank Hagelberg. "Interaction between Atomic Lanthanide Impurities and Ultrashort Carbon Nanotubes of the Zigzag Type". Journal of Physical Chemistry C 115, nr 11 (2.03.2011): 4571–77. http://dx.doi.org/10.1021/jp111927r.

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42

Sudorgin, S. A., i N. G. Lebedev. "Differential Thermal EMF of Carbon Zigzag-Type Nanotubes in an External Electric Field". Physics of the Solid State 62, nr 10 (październik 2020): 1928–32. http://dx.doi.org/10.1134/s1063783420100327.

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43

Kusunoki, M., T. Suzuki, C. Honjo, T. Hirayama i N. Shibata. "Selective synthesis of zigzag-type aligned carbon nanotubes on SiC (000−1) wafers". Chemical Physics Letters 366, nr 5-6 (grudzień 2002): 458–62. http://dx.doi.org/10.1016/s0009-2614(02)01463-x.

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44

Lei, Xiaowen, Toshiaki Natsuki, Jinxing Shi i Qing-Qing Ni. "Analysis of Carbon Nanotubes on the Mechanical Properties at Atomic Scale". Journal of Nanomaterials 2011 (2011): 1–10. http://dx.doi.org/10.1155/2011/805313.

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This paper aims at developing a mathematic model to characterize the mechanical properties of single-walled carbon nanotubes (SWCNTs). The carbon-carbon (C–C) bonds between two adjacent atoms are modeled as Euler beams. According to the relationship of Tersoff-Brenner force theory and potential energy acting on C–C bonds, material constants of beam element are determined at the atomic scale. Based on the elastic deformation energy and mechanical equilibrium of a unit in graphite sheet, simply form ED equations of calculating Young's modulus of armchair and zigzag graphite sheets are derived. Following with the geometrical relationship of SWCNTs in cylindrical coordinates and the structure mechanics approach, Young's modulus and Poisson's ratio of armchair and zigzag SWCNTs are also investigated. The results show that the approach to research mechanical properties of SWCNTs is a concise and valid method. We consider that it will be useful technique to progress on this type of investigation.

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45

García-Toral, Dolores, Raúl Mendoza-Báez, Ernesto Chigo-Anota, Antonio Flores-Riveros, Víctor M. Vázquez-Báez, Gregorio Hernández Cocoletzi i Juan Francisco Rivas-Silva. "Structural Stability and Electronic Properties of Boron Phosphide Nanotubes: A Density Functional Theory Perspective". Symmetry 14, nr 5 (9.05.2022): 964. http://dx.doi.org/10.3390/sym14050964.

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Based on the Density Functional Theory (DFT) calculations, we analyze the structural and electronic properties of boron phosphide nanotubes (BPNTs) as functions of chirality. The DFT calculations are performed using the M06-2X method in conjunction with the 6-31G(d) divided valence basis set. All nanostructures, (n,0) BPNT (n = 5–8, 10, 12, 14) and (n,n) BPNT (n = 3–11), were optimized minimizing the total energy, assuming a non-magnetic nature and a total charge neutrality. Results show that the BPNT diameter size increases linearly with the chiral index “n” for both chiralities. According to the global molecular descriptors, the (3,3) BPNT is the most stable structure provided that it shows the largest global hardness value. The low chirality (5,0) BPNT has a strong electrophilic character, and it is the most conductive system due to the small |HOMO-LUMO| energy gap. The chemical potential and electrophilicity index in the zigzag-type BPNTs show remarkable chirality-dependent behavior. The increase in diameter/chirality causes a gradual decrease in the |HOMO-LUMO| energy gap for the zigzag BPNTs; however, in the armchair-type BPNTs, a phase transition is generated from a semiconductor to a conductor system. Therefore, the nanostructures investigated in this work may be suggested for both electrical and biophysical applications.

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46

Umeno, Yoshitaka, Takayuki Kitamura i Akihiro Kushima. "Theoretical analysis on electronic properties of zigzag-type single-walled carbon nanotubes under radial deformation". Computational Materials Science 30, nr 3-4 (sierpień 2004): 283–87. http://dx.doi.org/10.1016/j.commatsci.2004.02.018.

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Thamira, Amin D. Thamira, Ali S. Hasan Hasan, Raheem G. Kadhim Kadhim, Watheq G. Bakheet Bakheet i Hamid I. Abbood Abbood. "Carbon Nanotubes Sensors for Gases Detection in Oil Industry". Journal of Petroleum Research and Studies 8, nr 3 (6.05.2021): 25–40. http://dx.doi.org/10.52716/jprs.v8i3.228.

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One of the most important uses of carbon nanotubes (CNTs) as a nanosensor for variouspolluted gases resulting from the burning of petroleum derivatives containing sulfur compoundsor extracted from the gases associated with petroleum, which are isolated by heat.In this investigation, we tested the adhesion of gas molecules connected with oil: we examinedthe adhesion of gas molecules connected with oil: sulfur dioxide (SO2) and hydrogen sulphide(H2S) on the surface of ((5,0) zigzag and length (100 nm)) CNTs using DFT calculations toexplore the high sensitivity to nanosensor for these molecules, which have gotten awesomeconsideration because of environmental and industrial considerations.From the results obtained in this study geometry optimization (structural properties) fornanosensor for useful assention with trial information. While the electronic properties includedcalculate total energy, HOMO energies, LUMO energies, ionization potential, electron affinity,potential electronic chemical, electronegativity, electrochemical hardness and electronic softness,also, the energy gap of the sensors under study has been calculated and the energy gap varies asstated by the type of gases to be detected. Moreover, we used orbital analysis counting the DOSto finding out the possible orbital hybridization between molecules and CNTs. From theseresults, we can say that the CNTs under study ((5,0) zigzag and the length (100 nm)) has a highsusceptibility to being an effective nanosensor for the gas molecules connected with the oil. Thistype of sensor(CNTs/SO2 or H2S) is standout amongst those a large portion essentialpersonalprotective equipment that is to warn the person of the presence of gases associated with oil,especially in areas of normal gas extraction.

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Wu, Ai Qing, Qing Gong Song i Li Yang. "First-Principles Study on Al or/and P Doped SiC Nanotubes". Advanced Materials Research 510 (kwiecień 2012): 747–52. http://dx.doi.org/10.4028/www.scientific.net/amr.510.747.

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The stability and electronic structures of Al or/and P doped single-walled SiC nanotubes (SWSiCNTs) are investigated by the first-principles theory. It is found that the ones with P atom located at Si site are most energetically favorable both for armchair and zigzag SWSiCNTs, which means that P atom is prone to substitute Si atom. In the same time, we found that the formation energy of Al substituting Si atom is lower than that of Al substituting C atom. The energetic disadvantages of P or Al atom located at C site in SWSiCNTs may be due to the obviously structural distortion in view of that the Al and P atoms are much bigger than C atom. The SWSiCNTs can be routinely modified ranging fromp-type semiconductor ton-type by Al and P substitution doping. These results are expected to give valuable information in building nanoscale electronic devices.

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Xiang, Yi, i Go Yamamoto. "A Data Mining Approach to Investigate the Carbon Nanotubes Mechanical Properties via High-Throughput Molecular Simulation". Materials Science Forum 1023 (marzec 2021): 29–36. http://dx.doi.org/10.4028/www.scientific.net/msf.1023.29.

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The relationship of geometrical properties and mechanical properties of carbon nanotubes (CNTs) was investigated by using high-throughput molecular simulation. Geometrical properties such as diameter, number of walls, chirality, and crosslink density were considered. As a key factor in determining the mechanical properties of composites reinforced with CNTs, nominal tensile strength is the focus in this study, which can be calculated by fracture force divided by the full cross-sectional area including the hollow core and the wall thickness. The fracture mode, nominal tensile strength, and nominal Young’s modulus under the condition of CNTs outermost tube loading axial tensile test were evaluated. Three types of fracture modes led by different crosslink densities of CNTs were obtained. By data-mining through large amounts of datasets, we showed that CNTs with small diameter, large number of walls, and crosslinks between walls can have high nominal tensile strength. We demonstrated that zigzag-type CNTs with crosslink density of approximately 1.5% - 2.5%, armchair-type CNTs with crosslink density of approximately 3% - 4% can help improve the load transfer from the outer tube to the inner tube the most.

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Salmankhani, Azam, Zohre Karami, Amin Hamed Mashhadzadeh, Mohammad Reza Saeb, Vanessa Fierro i Alain Celzard. "Mechanical Properties of C3N Nanotubes from Molecular Dynamics Simulation Studies". Nanomaterials 10, nr 5 (7.05.2020): 894. http://dx.doi.org/10.3390/nano10050894.

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Although the properties of carbon nanotubes (CNTs) are very well-known and are still extensively studied, a thorough understanding of other carbon-based nanomaterials such as C3N nanotubes (C3NNTs) is still missing. In this article, we used molecular dynamics simulation to investigate the effects of parameters such as chirality, diameter, number of walls, and temperature on the mechanical properties of C3N nanotubes, C3N nanobuds, and C3NNTs with various kinds of defects. We also modeled and tested the corresponding CNTs to validate the results and understand how replacing one C atom of CNT by one N atom affects the properties. Our results demonstrate that the Young’s modulus of single-walled C3NNTs (SWC3NNTs) increased with diameter, irrespective of the chirality, and was higher in armchair SWC3NNTs than in zigzag ones, unlike double-walled C3NNTs. Besides, adding a second and then a third wall to SWC3NNTs significantly improved their properties. In contrast, the properties of C3N nanobuds produced by attaching an increasing number of C60 fullerenes gradually decreased. Moreover, considering C3NNTs with different types of defects revealed that two-atom vacancies resulted in the greatest reduction of all the properties studied, while Stone–Wales defects had the lowest effect on them.

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