scholarly journals Spectroscopy of a rotating hydrogen molecule in carbon nanotubes

2019 ◽  
Vol 21 (7) ◽  
pp. 3423-3430 ◽  
Author(s):  
María Pilar de Lara-Castells ◽  
Alexander O. Mitrushchenkov
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Hydrogen ◽  
Hydrogen Molecule ◽  
Energy Levels

Computing the energy levels of molecular hydrogen rotating in carbon nanotubes of increasing size.

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.

EFFECTS OF COMPLEXING ON THE HOMOGENEOUS REDUCTION OF MERCURIC SALTS IN AQUEOUS SOLUTION BY MOLECULAR HYDROGEN

1956 ◽  
Vol 34 (10) ◽  
pp. 1372-1381 ◽  
Author(s):  
G. J. Korinek ◽  
J. Halpern
Keyword(s):  
Aqueous Solution ◽  
Molecular Hydrogen ◽  
Hydrogen Molecule ◽  
Bimolecular Reaction ◽  
Mercury Atom ◽  
Complexing Agents ◽  
Mercuric Ion ◽  
Rate Determining Step ◽  
Homogeneous Reduction

The effects of various complexing agents on the homogeneous reduction of mercuric salts by molecular hydrogen in aqueous solution were determined. In all cases the kinetics suggest that the rate-determining step is a bimolecular reaction between a mercuric ion or complex and a hydrogen molecule, probably leading to the formation of an intermediate mercury atom. The reactivity of various mercuric complexes was found to decrease in the following order: HgSO4 > Hg++ > HgAc2, HgPr2 > HgCl2 > HgBr2 > Hg(EDA)2++. Addition of anions such as OH−, CO3=, Ac−, Pr−, and Cl−, in excess of the amounts required to form stable mercuric complexes, was found to increase the rate. An interpretation of these effects is given.

scholarly journals The band spectrum of hydrogen

1924 ◽  
Vol 106 (735) ◽  
pp. 69-82 ◽  
Keyword(s):  
Molecular Hydrogen ◽  
Hydrogen Molecule ◽  
Spectral Lines ◽  
Wave Number ◽  
Band Spectrum ◽  
Wave Numbers ◽  
Experimental Side ◽  
The Subject ◽  
The Moment ◽  
Theoretical Side

Many attempts have been made to detect regularities amongst the numerous lines which constitute the secondary or many-lined spectrum of hydrogen. The extreme complexity of the spectrum may be realised from the fact that in the Bakerian Lecture of 1922 Merton and Barratt record some 750 lines in the interval between Hα (wave-number v = 5233.216) and Hβ ( v = 20564.793). Three methods of investigation may be employed in the search for regularities. (1) The lines may be classified according to their physical characteristics, such as intensity or mode of excitation, as in the tables of Merton and Barrat ( loc. cit .). (2) Lines may be grouped together by the discovery of relations between their wave-lengths or wave-numbers, as in the important groups of lines which have been arranged in bands by Fulcher. (3) Lastly, the question may be attacked from the theoretical side, and a model of the hydrogen molecule may be imagined, which will give rise to the emission of certain characteristic spectral lines. Thus Sutherland, working on the foundation of the classical mechanical laws, more than twenty years ago, came to the conclusion that spectral series must arise from kinematical considera­tions, and explained them by considering the nodal sub-divisions of a circle. At the present time we may expect more successful results to follow from the application of the quantum theory, and in this paper an endeavour will be made to examine the secondary spectrum of hydrogen, and more particularly the Fulcher bands, from this standpoint. I may add that my interest in the subject was aroused when attempting to construct a model of the hydrogen molecule, for it seemed that the most likely method of obtaining reliable information from the experimental side as to the moment of inertia of the molecule would be from a study of the spectrum of molecular hydrogen.

scholarly journals Rovibrational energy levels of the hydrogen molecule through nonadiabatic perturbation theory

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
Jacek Komasa ◽  
Mariusz Puchalski ◽  
Paweł Czachorowski ◽  
Grzegorz Łach ◽  
Krzysztof Pachucki
Keyword(s):  
Perturbation Theory ◽  
Hydrogen Molecule ◽  
Energy Levels

scholarly journals Assessing the Damage Tolerance of Out of Autoclave Manufactured Carbon Fibre Reinforced Polymers Modified with Multi-Walled Carbon Nanotubes

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1080 ◽  
Author(s):  
Polyxeni Dimoka ◽  
Spyridon Psarras ◽  
Christine Kostagiannakopoulou ◽  
Vassilis Kostopoulos
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Reference Material ◽  
Carbon Fibre ◽  
Damage Tolerance ◽  
Energy Levels ◽  
Multi Walled Carbon Nanotubes ◽  
Out Of Autoclave ◽  
Walled Carbon Nanotubes ◽  
The Impact

The present study aims to investigate the influence of multi-walled carbon nanotubes (MWCNTs) on the damage tolerance after impact (CAI) of the development of Out of Autoclave (OoA) carbon fibre reinforced polymer (CFRP) laminates. The introduction of MWCNTs into the structure of CFRPs has been succeeded by adding carbon nanotube-enriched sizing agent for the pre-treatment of the fibre preform and using an in-house developed methodology that can be easily scaled up. The modified CFRPs laminates with 1.5 wt.% MWCNTs were subjected to low velocity impact at three impact energy levels (8, 15 and 30 J) and directly compared with the unmodified laminates. In terms of the CFRPs impact performance, compressive strength of nanomodified composites was improved for all energy levels compared to the reference material. The test results obtained from C-scan analysis of nano-modified specimens showed that the delamination area after the impact is mainly reduced, without the degradation of compressive strength and stiffness, indicating a potential improvement of damage tolerance compared to the reference material. SEM analysis of fracture surfaces revealed the additional energy dissipation mechanisms; pulled-out carbon nanotubes which is the main reason for the improved damage tolerance of the multifunctional composites.

scholarly journals First-Principles Study of Molecular Adsorption of Hydrogen/s on Co-Adatom Graphene

2020 ◽  
Vol 25 (1) ◽  
pp. 15-23
Author(s):  
Nurapati Pantha ◽  
Saroj Thapa ◽  
Narayan Prasad Adhikari
Keyword(s):  
Magnetic Properties ◽  
Binding Energy ◽  
First Principles ◽  
Molecular Hydrogen ◽  
Density Functional ◽  
Hydrogen Molecule ◽  
Cobalt Atom ◽  
Electronic Charge ◽  
Practical Applications ◽  
Electronic And Magnetic Properties

The study of graphene and its allotropes help to understand fundamental science and their role in the industry. The adsorption of transition metal adatom on mono-layer graphene can tune the geometrical, electronic, and magnetic properties of the material according to the requirement for the practical applications. In the present work, the geometrical stability, electronic and magnetic properties, and also the redistribution of electronic charge of single cobalt atom (Co) adsorbed graphene with reference to pure graphene have been investigated to develop a model system for the effective storage of hydrogen. The density functional theory (DFT) based first-principles calculations by incorporating van der Waals (VDW) interactions within DFT-D2 levels of approximation implemented in the quantum ESPRESSO package was used. The band structure and density of states of cobalt-adatom graphene show that the material is metallic and magnetic with a total magnetic moment of 1.55 μB. The change in the electronic distribution of Co-adatom graphene has been found favorable for adsorbing molecular hydrogen/s with greater strength. The increasing number of adsorbed molecular hydrogen/s (n=1 to 7) onto the substrate shows varying binding energy per hydrogen molecule, high enough at low concentration (n=1, 2, and 3), and then decreases slowly on increasing the value of n. The nature of adsorption and binding energy per hydrogen molecule (with a range of 0.116 - 0.731 eV/ H2) are found useful to meet a standard target for hydrogen storage in such materials.

scholarly journals DISPERSION INTERACTION OF ATOMS WITH SINGLE-WALLED CARBON NANOTUBES DESCRIBED BY THE DIRAC MODEL

2011 ◽  
Vol 03 ◽  
pp. 555-563 ◽  
Author(s):  
YU. V. CHURKIN ◽  
A. B. FEDORTSOV ◽  
G. L. KLIMCHITSKAYA ◽  
V. A. YUROVA
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Atom ◽  
Interaction Energy ◽  
Hydrogen Molecule ◽  
Single Walled Carbon Nanotubes ◽  
Hydrogen Atoms ◽  
Single Walled Carbon ◽  
Atoms And Molecules ◽  
Proximity Force Approximation ◽  
Walled Carbon Nanotubes

We calculate the interaction energy and force between atoms and molecules and single-walled carbon nanotubes described by the Dirac model of graphene. For this purpose the Lifshitz-type formulas adapted for the case of cylindrical geometry with the help of the proximity force approximation are used. The results obtained are compared with those derived from the hydrodymanic model of graphene. Numerical computations are performed for hydrogen atoms and molecules. It is shown that the Dirac model leads to larger values of the van der Waals force than the hydrodynamic model. For a hydrogen molecule the interaction energy and force computed using both models are larger than for a hydrogen atom.

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