Decomposition Patterns of Three C 20 Isomer Clusters: Tight‐binding Molecular Dynamics Simulation

Bulletin Korean Chem Soc

et al. 2019

Self Cite

We have studied the fragmentation of C60 fullerenes in a single wall carbon nanotube using the molecular dynamic simulations combined with the empirical‐tight‐binding total‐energy‐calculation method. We show the chemical binding structure of carbon nanopeapod (CNP) comprised of single‐wall carbon nanotube (SWNT) and C60 fullerene molecule and the geometrical spatial positioning structure of C60 inside in the SWNT as a function of dynamic time for 2 ps at each temperature of 4000, 5000, and 6000 K. Therefore, using the snapshots, it could be shown that one is consistent with a previous study that the passage of thermal conductivity in the CNP is mainly transmitted through C60 rather than CNT, and the other is to carefully suggest that the scenario in which C60@SWNT forms a double‐walled carbon nanotube is followed by the destruction of C60 after the combination of C60 and SWNT is made in the early stages.

Section: Introductionmentioning

confidence: 99%

Dynamic Behavior of C₆₀ Fullerene in Carbon Nanopeapods: Tight‐Binding Molecular Dynamics Simulation

Bulletin Korean Chem Soc

et al. 2019

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“…This potential has been successfully applied to various carbon systems [ 14 , 15 , 16 , 17 ]. In addition, the fragmentation of C 60 [ 18 ] and C 70 [ 19 ] clusters, C 20 isomer clusters [ 20 ], and C 60 @SWCNT [ 7 ], and (C 60 ) 2 @SWCNT [ 8 ] has already been studied using these TBMD parameters.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

IJMS

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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.

“…3,4 Chemical reactions by monitoring time-dependent changes in the atomic position that respond to molecules for the study of the bifurcation reaction of fullerenes inside carbon nanotubes were visualized by the high-resolution transmission electron microscopy (HR TEM) was used as a function of electron dose. [12][13][14][15] In the TBMD calculations, we use 7.08 × 10 −16 s as one-time step. Through counting reaction events one by one using HR TEM, it was proposed to convert the excited state path and thermal relaxation, the radical cation path of the C 60 dimer from the electron-damaged SWNT, and a conversion of the C 60 dimer into a fused dimer.…”

mentioning

confidence: 99%

“…Herein, carbon system parameters were obtained by means of reproducing the universal binding energy curves of the various stages obtained on the basis of calculations of the first principles. [12][13][14][15] In the TBMD calculations, we use 7.08 × 10 −16 s as one-time step. [8][9][10][11] In addition, studies using these TBMD parameters have already reported the fragmentation of C 60 and C 70 clusters, C 20 isomer clusters, and C 60 @SWNT.…”

mentioning

confidence: 99%

A Conversion Dynamics of (C₆₀)₂ Dimer Fullerenes to a Fused Dimer Cage in Carbon Nanopeapods: Tight‐Binding Molecular Dynamics Simulation

Bulletin Korean Chem Soc

et al. 2019

Self Cite

2 dimer fullerenes to fused cages in a single-walled nanotube, NanopeapodUsing the internal space of the within single-walled carbon nanotube (SWNT) as a nanometer-scale reaction chamber, double-walled carbon nanotubes (DWNTs) forming secondary tubes inside the SWNT have been reported. It can be explained quantitatively that the DWNT is made through the decomposition and conversion process of C 60 molecules arranged in the form of a chain within an SWNT. 1,2 Molecular dynamics are an important way to understand the chemical reaction process of SWNT. 3,4 Chemical reactions by monitoring time-dependent changes in the atomic position that respond to molecules for the study of the bifurcation reaction of fullerenes inside carbon nanotubes were visualized by the high-resolution transmission electron microscopy (HR TEM) was used as a function of electron dose. 5,6 Using HR TEM techniques, molecular motion and their conformational changes, the chemical reaction to dimerization of fullerene in SWNT were reported. Through counting reaction events one by one using HR TEM, it was proposed to convert the excited state path and thermal relaxation, the radical cation path of the C 60 dimer from the electron-damaged SWNT, and a conversion of the C 60 dimer into a fused dimer. 6 The exact mechanism behind the formation of carbon materials is difficult to elucidate because the control of many of the experimental conditions is still challenging. Therefore, it would be very interesting to study a conversion of (C 60 ) 2 fullerene dimer molecules to a fused dimer encapsulated within a SWNT, using molecular dynamics simulations together with the empirical tight-binding method for total energy calculations (TBMD). The fragmentation behavior of SWNPs encapsulating C 60 dimer is an indirect way in order to figure out the conversion mechanism underlying fused dimer formation.In this study, the accuracy of our calculations depended on the selection of relevant empirical tight-binding parameters for the calculation of electronic band structure of empirical TBMD method. Herein, carbon system parameters were obtained by means of reproducing the universal binding energy curves of the various stages obtained on the basis of calculations of the first principles. 7 The parameters have been successfully applied to various carbon systems, demonstrating its potential. [8][9][10][11] In addition, studies using these TBMD parameters have already reported the fragmentation of C 60 and C 70 clusters, C 20 isomer clusters, and C 60 @SWNT. [12][13][14][15] In the TBMD calculations, we use 7.08 × 10 −16 s as one-time step. As a convergence criterion of the total energy calculations, 10 −3 eV was used on the energy surface over the microcanonical ensemble at room temperature. The TBMD simulations were performed in thousands of time steps to ensure equilibrium. The system was set up to rerun 1500 time steps at a specific temperature over a temperature control method called the canonical ensemble, and then 1000 time steps over the microcanonical ensemble. At...