Dynamic Behavior of C60 Fullerene in Carbon Nanopeapods: Tight-Binding Molecular Dynamics Simulation (original) (raw)
Related papers
International Journal of Molecular Sciences
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...
Molecular dynamics simulation of carbon nanostructures: The D5h C70 fullerene
Physica E: Low-dimensional Systems and Nanostructures, 2014
Molecular dynamics calculations can reveal the physical and chemical properties of various carbon nanostructures or can help to devise the possible formation pathways. In our days the most well known carbon nanostructures are the fullerenes and the nanotubes. They can be thought of as being formed from graphene sheets, i.e. single layers of carbon atoms arranged in a honeycomb lattice. Usually the nature does not follow the mathematical constructions. An ideal nanotube can be thought of as a hexagonal network of carbon atoms that has been rolled up to make a cylinder. There is not any theory of carbon nanotube formation which is based on this construction. Although the first time the C 60 and C 70 were constructed by laser irradiated graphite, the fullerene formation theories are based on various fragments of carbon chains, and networks of pentagonal and hexagonal rings. In the present article different initial patterns will be given for the formation of the C 70 fullerene with D 5h symmetry. The desired final structures are obtained in tight-binding molecular dynamics calculations.
Brazilian Journal of Physics, 2008
This work aim is to determine how a C 60 fullerene, encapsulated into a (10,10) carbon nanotube, can be ballistically expelled from it by using a colliding capsule. Initially, the C 60 fullerene is positioned at rest inside the nanotube. The capsule, also starting from rest but outside of the nanotube, is put in a position such that it can be trapped towards the interior of the nanotube by attraction forces between their atoms. The energy gain associated to the capsule penetration is kinetic energy, giving rise to a high velocity for it. When the capsule reaches the C 60 fullerene, it transfers energy to it in an amount that enables the fullerene to escape from the nanotube. The mechanical behavior was simulated by classical molecular dynamics. The intermolecular interactions are described by a van der Waals potential while the intramolecular interactions are described by an empirical Tersoff-Brenner potential for the carbon system.
How Confinement Affects the Dynamics of C60 in Carbon Nanopeapods
Physical Review Letters, 2008
The dynamics of confined systems is of major concern for both fundamental physics and applications. In this Letter, the dynamics of C 60 fullerene molecules inside single walled carbon nanotubes is studied using inelastic neutron scattering. We identify the C 60 vibrations and highlight their sensitivity to temperature. Moreover, a clear signature of rotational diffusion of the C 60 is evidenced, which persists at lower temperature than in 3D bulk C 60 . It is discussed in terms of confinement and of reduced dimensionality of the C 60 chain.
Energetics and stability of C60 molecules encapsulated in carbon nanotubes
Carbon, 2008
An energetic analysis was performed to study the interactions of C 60 molecules encapsulated in carbon nanotubes. Both direct interaction between C 60 molecules through van der Waals forces and indirect interaction between encapsulated C 60 molecules through the elastic deformation of their host carbon nanotubes were considered. For C 60 s encapsulated in a (9, 9) nanotube, the indirect interaction dominates and a relatively large energy barrier exists for the formation of a uniform, stable, one-dimensional (1-D) C 60 array. For a (10, 10) nanotube, the indirect interaction leads to a small energy barrier to form a 1-D C 60 array, while for a (11, 11) nanotube the influence of the indirect interaction is negligible. Molecular dynamics simulations were performed to confirm the present energetic analysis, suggesting that the indirect interaction between encapsulated molecules/particles through the elastic deformation of their host nanotubes may affect the stability of nanotube-based structures.
Physical Review B, 2002
We report recent measurements of the electronic and structural properties of bulk samples of C 60 molecules encapsulated in single-wall carbon nanotubes ͑so-called peapods͒ using electron-energy-loss spectroscopy in transmission. We demonstrate that C 60 peapods with a single-wall carbon nanotube ͑SWNT͒ diameter distribution of 1.37Ϯ0.08 nm have an average fullerene filling of 60%. Regarding the electronic and optical properties, the overall shape of the response of the SWNT and the peapods is very similar, but with distinct differences in the fine structure. The interband transitions of the SWNT are slightly downshifted in the peapods, which can be explained by either a small increase of the SWNT diameter or by a change of the intertube interaction. The electronic and optical properties of the encapsulated C 60 peas closely resemble those of solid fcc C 60 showing small changes in the relative intensities, peak positions, and peak width, which point to a weak van der Waals interaction between the tubes and the encapsulated fullerenes.
Statistical Analysis of Fullerene C 60 Geometry Temperature Dynamics by Molecular Dynamics
In this paper, the analysis of changes in the radius of fullerene C 60 as a function of temperature in a wide temperature range (10-900K) is presented. The values of the average radius of fullerene C 60 are within the range of 3.64-3.65Å for the selected potential. It is obtained that the time of dynamic stabilization of the fullerene geometry after program thermalization is at least 30ps. It was obtained that the mean radius of fullerene C 60 has a non-strictly monotonical increase in its value with the temperature increase, while as this dependence cannot be considered continuous. Dynamic data is obtained using the LAMMPS software package.
2003
The computations were performed using a dual CPU (2x2.0 GHz) personal computer (PC) motherboard, with the AM1, PM3, MNDO, and MINDO/3 semi-empirical quantum-chemical methods. Optimized bond distances, effective charge values, total energies, heats of formation and core-core interactions were calculated for zigzag and armchair type capped SWCNTs with maximum stoichiometry C 168 and C 160 , respectively. For C 60 and C 70 fullerenes, Gaussian STO-3G ab-initio and B3-LYP/3-21G* DFT calculations were additionally performed, allowing us to compare the computed results with the experimental ones. We have shown that currently available relatively low-cost high-power personal computers can be successfully used in semi-empirical quantumchemical computations even for large-sized carbon nano-structures, for which optimized structures provide data being in good agreement with the experimental results.
Fullerene and graphene formation from carbon nanotube fragments
Computational and Theoretical Chemistry, 2012
We study the long-time annealing behavior of 60-atom fragments of carbon nanotubes using two accelerated molecular dynamics methods. We find that this behavior depends strongly on the geometry of the nanotube fragment. Fragments from (n, n) nanotubes with n 6 5 quickly form closed structures. Whether the terminations of (n, 0) fragments (n 6 9) close depends on the structure of the termination. Those forming a zigzag structure remain open for the duration of our simulations. Fragments from (n, n) nanotubes with n P 6 exhibit surprising behavior, with (7, 7) fragments unfolding to form thermodynamically unfavorable graphene fragments. These results suggest that small-radius (n, n) fragments will be unreactive with other molecules, large-radius (n, n) fragments will react with other molecules, and the reactivity of (n, 0) fragments will depend on the details of their structure. We include a discussion of the accelerated molecular dynamics methods and some of the implementation details to give the reader a sense of how they can be effectively applied to this kind of system.