Distance‐based topological descriptors for measuring the π ‐electronic energy of benzenoid hydrocarbons with applications to carbon nanotubes

2020 ◽  
Author(s):  
Sakander Hayat ◽  
Suliman Khan ◽  
Asad Khan ◽  
Muhammad Imran
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Energy ◽  
Topological Descriptors ◽  
Benzenoid Hydrocarbons

Quantum Mechanical Investigation of Geometrical Structure and Dynamic Behavior of h-BNNT (9,9-5) and h-AlNNT (9,9-5)Single-Walled Nanotubes: NBO Analysis

2019 ◽  
Vol 16 (9) ◽  
pp. 705-717
Author(s):  
Mehrnoosh Khaleghian ◽  
Fatemeh Azarakhshi
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional ◽  
Structural Parameters ◽  
Energy Levels ◽  
Nbo Analysis ◽  
Electronic Energy ◽  
Boron Nitride Nanotubes ◽  
Basis Set ◽  
B3lyp Method ◽  
Mechanical Investigation

In the present research, B45H36N45 Born Nitride (9,9) nanotube (BNNT) and Al45H36N45 Aluminum nitride (9,9) nanotube (AlNNT) have been studied, both having the same length of 5 angstroms. The main reason for choosing boron nitride nanotubes is their interesting properties compared with carbon nanotubes. For example, resistance to oxidation at high temperatures, chemical and thermal stability higher rather than carbon nanotubes and conductivity in these nanotubes, unlike carbon nanotubes, does not depend on the type of nanotube chirality. The method used in this study is the density functional theory (DFT) at Becke3, Lee-Yang-Parr (B3LYP) method and 6-31G* basis set for all the calculations. At first, the samples were simulated and then the optimized structure was obtained using Gaussian 09 software. The structural parameters of each nanotube were determined in 5 layers. Frequency calculations in order to extract the thermodynamic parameters and natural bond orbital (NBO) calculations have been performed to evaluate the electron density and electrostatic environment of different layers, energy levels and related parameters, such as ionization energy and electronic energy, bond gap energy and the share of hybrid orbitals of different layers.

On Topological Properties of 2-Dimensional Lattices of Carbon Nanotubes

2016 ◽  
Vol 13 (10) ◽  
pp. 6606-6615
Author(s):  
Sakander Hayat ◽  
Muhammad Kashif Shafiq ◽  
Asad Khan ◽  
Hassan Raza ◽  
Hafiz Muhmmad Afzal Siddiqui ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Quaternary Structure ◽  
Topological Indices ◽  
Topological Descriptors ◽  
Structure Property ◽  
Specific Chemical ◽  
Carbon Nanosheets ◽  
Chemical Significance ◽  
Numerical Invariants ◽  
Intermediate Size

Topological descriptors are the most important numerical quantities in the fields of mathematical chemistry and nanotechnology. These numerical descriptors are based on the topology of the atoms and their bonds (chemical conformation, quaternary structure). Local-valency/degree based topological descriptors/indices are of vital importance due to their specific chemical significance. These numerical invariants are the most successful molecular descriptors in structure-property and structure-activity relationships studies. A nanostructure is an object of intermediate size between molecular and microscopic structures. It is a product derived through engineering at the molecular scale. The most important of these new materials are carbon nanotubes. They have remarkable electronic properties and many other unique characteristics. Carbon nanosheets are 2-dimensional lattices of carbon nanotubes. To compute and study topological indices of nanostructures is a respected problem in nanotechnology. In this paper, degree based topological indices of certain carbon nanosheets are strong-minded. We formulate an important conjecture at the end of this article.

scholarly journals Computation of General Zagreb Index of Nanotubes Covered by C5 and C7

2020 ◽  
Vol 11 (1) ◽  
pp. 8001-8008
Keyword(s):  
Carbon Nanotubes ◽  
Connected Graph ◽  
Molecular Graph ◽  
Topological Indices ◽  
Topological Descriptors ◽  
Chemical Bonds ◽  
Graph Invariant ◽  
Zagreb Index ◽  
Physical And Chemical ◽  
Simple Connected Graph

A molecular graph is hydrogen deleted simple connected graph in which vertices and edges are represented by atoms and chemical bonds, respectively. Topological indices are numerical parameters of a molecular graph which characterize its topology and are usually graph invariant. In Mathematical chemistry, topological descriptors play an important role in modeling different physical and chemical activities of molecules. In this study, the generalized Zagreb index for three types of carbon nanotubes is computed. By putting some particular values to the parameters, some important degree-based topological indices are also derived.

Absorption Spectrum of Carbon Nanotubes

2014 ◽  
Vol 633-634 ◽  
pp. 3-6
Author(s):  
Qing Hua Zhang ◽  
Hong Hui Sun ◽  
Hong Xia Wang
Keyword(s):  
Carbon Nanotubes ◽  
Absorption Spectrum ◽  
Energy Level ◽  
High Energy ◽  
Electronic Energy ◽  
Energy Bands ◽  
High Energy Level ◽  
Wave Absorption ◽  
Quantum Size ◽  
Electronic Energy Bands

Carbon nanotubes are very typical nanomaterials, because the electron π of carbon nanotubes is restricted by the quantum size, the energy bands of the electron π are discontiguous and the characteristic of its energy level is divisive. The electron π can absorb the photon and makes transition from low energy level to high energy level, so it has the characteristic of wave-absorption . Based on the theory of quantum mechanics and the atomic structure of carbon nanotubes, the electronic energy bands and absorption spectrum of carbon nanotubes are analyzed in this paper, the results show that carbon nanotubes of different size correspond with absorption spectrum of different wave bands, and the computational results are afforded for the bases of designing wave-absorption materials.

Electronic energy loss of protons and deuterons in multi-walled carbon nanotubes

2017 ◽  
Vol 71 (3) ◽  
Author(s):  
Carlos E. Celedón ◽  
Andrea Cortés ◽  
Esteban A. Sánchez ◽  
M. Sergio Moreno ◽  
Juan David Uribe ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Energy Loss ◽  
Electronic Energy ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

EFFECT OF BOND ALTERNATION ON ELECTRONIC ENERGY BAND STRUCTURE OF ARMCHAIR CARBON NANOTUBES

2011 ◽  
Vol 25 (12n13) ◽  
pp. 1013-1018 ◽  
Author(s):  
TRAN CONG PHONG ◽  
NGUYEN NGOC HIEU
Keyword(s):  
Carbon Nanotubes ◽  
Band Structure ◽  
Band Gap ◽  
Energy Band ◽  
Electronic Energy ◽  
Kekulé Structure ◽  
Energy Band Structure ◽  
Tight Binding Approximation ◽  
Bond Alternation ◽  
Electronic Energy Band

The influence of the bond alternation on electronic energy band structure of armchair carbon nanotubes is studied by the tight-binding approximation. It is shown that the armchair carbon nanotubes at ground state with Kekule structure open small band gap at the Fermi level. Dependence of energy band gap of armchair carbon nanotubes with Kekule structure on their radius is considered and numerically calculated. The numerical calculations are applied to the (n, n) carbon nanotubes with n = 5, 6, 7, 8.

Fabrication of Carbon Nanotubes Patterns on Titanium Surface by Microcontact Printing

2013 ◽  
Vol 647 ◽  
pp. 672-675
Author(s):  
Chang Jiang Pan ◽  
Yu Dong Nie
Keyword(s):  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Titanium Surface ◽  
Microcontact Printing ◽  
Electronic Energy ◽  
Water Contact

In recent years, carbon nanotubes attract much attention in many fields such as biomaterials, drug delivery system, electronics and others. In the present study, we use microcontact printing (μCP) to fabricate CNT patterns on titanium surface. The water contact angel and AFM experiments shows that the CNTs are successfully immobilized on titanium surface. SEM results show that the CNT patterns were obtained successfully. We anticipate this approach would provide a new route to generate CNT patterns for advanced electronic, energy, and biomaterials applications.

ELECTRONIC BAND STRUCTURE OF CARBON NANOTUBES WITH QUINOID STRUCTURE

2013 ◽  
Vol 27 (25) ◽  
pp. 1350179
Author(s):  
NGUYEN NGOC HIEU ◽  
NGUYEN PHAM QUYNH ANH
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Band Structure ◽  
Electronic Band Structure ◽  
Tight Binding ◽  
Electronic Energy ◽  
Electronic Band ◽  
Tight Binding Approximation ◽  
Quinoid Structure ◽  
Structure Of Carbon Nanotubes

In this paper, we fully describe the geometry of atomic structure of carbon nanotube with quinoid structure. Electronic energy band structure of carbon nanotubes with quinoid structure is studied by tight-binding approximation. In the presence of bond alternation, calculations show that only armchair (n, n) carbon nanotube (without twisting) remains metallic and zigzag (3ν - 1, -3ν + 1) CNT becomes metallic at the critical elongation. Effect of deformation on the change of band gap is also calculated and discussed.

Electronic structure of helically coiled carbon nanotubes

2005 ◽  
Vol 901 ◽  
Author(s):  
Gian Giacomo Guzman-Verri ◽  
Lok C. Lew Yan Voon ◽  
Morten Willatzen ◽  
Jens Gravesen
Keyword(s):  
Carbon Nanotubes ◽  
Band Structure ◽  
Electronic Band Structure ◽  
Electronic Energy ◽  
Electronic Band ◽  
Curvature Effects ◽  
Helical Carbon Nanotubes ◽  
Coil Diameter ◽  
Curvature Energy ◽  
Effective Mass Approach

AbstractIn the present work we calculate the electronic band structure of single-wall helical carbon nanotubes following an effective-mass approach. We include curvature effects and strain due to bending in the band structure. The curvature energy ΔE, and the change in the electronic energy ΔEs due to strain, depend upon the coil pitch and coil diameter of the tube. We find 0.003 ≤|ΔE|≤ 1.3 eV and 0 ≤ΔEs ≤ 4.0 eV for the single-wall helical carbon nanotubes considered here.

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