Molecular Dynamics Simulation of a Pullout Test on a Carbon Nanotube in a Polymer Matrix

2014 ◽  
Vol 1700 ◽  
pp. 61-66
Author(s):  
Guttormur Arnar Ingvason ◽  
Virginie Rollin
Keyword(s):  
Molecular Dynamics ◽  
Polymer Matrix ◽  
Large Scale ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Atomistic Simulations ◽  
Polymer Molecules ◽  
Molecular Potential ◽  
Pull Out ◽  
Walled Carbon Nanotubes

ABSTRACTAdding single walled carbon nanotubes (SWCNT) to a polymer matrix can improve the delamination properties of the composite. Due to the complexity of polymer molecules and the curing process, few 3-D Molecular Dynamics (MD) simulations of a polymer-SWCNT composite have been run. Our model runs on the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS), with a COMPASS (Condensed phase Optimized Molecular Potential for Atomistic Simulations Studies) potential. This potential includes non-bonded interactions, as well as bonds, angles and dihedrals to create a MD model for a SWCNT and EPON 862/DETDA (Diethyltoluenediamine) polymer matrix. Two simulations were performed in order to test the implementation of the COMPASS parameters. The first one was a tensile test on a SWCNT, leading to a Young’s modulus of 1.4 TPa at 300K. The second one was a pull-out test of a SWCNT from an originally uncured EPON 862/DETDA matrix.

scholarly journals Understanding Covalent Grafting of Nanotubes onto Polymer Nanocomposites: Molecular Dynamics Simulation Study

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2621
Author(s):  
Seunghwa Yang
Keyword(s):  
Molecular Dynamics ◽  
Load Transfer ◽  
Cell Model ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Covalent Grafting ◽  
Modelling Strategies ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
External Loads

Here, we systematically interrogate the effects of grafting single-walled (SWNT) and multi-walled carbon nanotubes (MWNT) to polymer matrices by using molecular dynamics (MD) simulations. We specifically investigate key material properties that include interfacial load transfer, alteration of nanotube properties, and dispersion of nanotubes in the polymer matrix. Simulations are conducted on a periodic unit cell model of the nanocomposite with a straight carbon nanotube and an amorphous polyethylene terephthalate (PET) matrix. For each type of nanotube, either 0%, 1.55%, or 3.1% of the carbon atoms in the outermost nanotubes are covalently grafted onto the carbon atoms of the PET matrix. Stress-strain curves and the elastic moduli of nanotubes and nanocomposites are determined based on the density of covalent grafting. Covalent grafting promotes two rivalling effects with respect to altering nanotube properties, and improvements in interfacial load transfer in the nanocomposites are clearly observed. The enhanced interface enables external loads applied to the nanocomposites to be efficiently transferred to the grafted nanotubes. Covalent functionalization of the nanotube surface with PET molecules can alter the solubility of nanotubes and improve dispersibility. Finally, we discuss the current limitations and challenges in using molecular modelling strategies to accurately predict properties on the nanotube and polymers systems studied here.

Molecular Dynamics Simulation of Bi-Carboxyl Sidewall Functionalized Single-Wall Carbon Nanotubes in Water

2015 ◽  
Vol 1131 ◽  
pp. 106-109
Author(s):  
Shongpun Lokavee ◽  
Chatchawal Wongchoosuk ◽  
Teerakiat Kerdcharoen
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Single Wall Carbon Nanotubes ◽  
First Principles Calculations ◽  
Carboxylic Groups ◽  
Potential Applications ◽  
Walled Carbon Nanotubes ◽  
Defective Sites

Functionalized single-walled carbon nanotubes (f-SWNTs) have attracted great interest due to their enhancement of SWNT properties leading to an increase in potential applications beyond those of pristine SWNT. In this work, we have investigated the behavior of open-end (9,0) bi-carboxyl sidewall functionalized SWNTs in water using molecular dynamics (MD) technique within GROMACS software package based on the OPLS force fields with modified charges obtained from the first principles calculations. The model tubes including perfect and defective nanotubes covalently functionalized by bi-carboxylic groups on different sidewall surface orientation were fully optimized by B3LYP/6-31G(d,p). The simulations were performed at the constant volume and temperature in a rectangular box with periodic boundary conditions in which each system contains one model tube and ~1680 water molecules. The results form MD simulations showed that functionalization on the central carbon atom in the (C1,C ́1)SW-defective sites strongly affects on the dynamic behavior of CNT in water. Results showed that the hydrophilic behavior of the functionalized SWNT has been improved over the pristine and defective nanotubes.

LARGE-SCALE MOLECULAR-DYNAMICS SIMULATION OF 19 BILLION PARTICLES

2004 ◽  
Vol 15 (01) ◽  
pp. 193-201 ◽  
Author(s):  
KAI KADAU ◽  
TIMOTHY C. GERMANN ◽  
PETER S. LOMDAHL
Keyword(s):  
Molecular Dynamics ◽  
Large Scale ◽  
Dynamics Simulation ◽  
Atomistic Simulations ◽  
Huge Number ◽  
Physical Problems ◽  
Efficient Data ◽  
Dynamics Simulations ◽  
Large Scale Simulations ◽  
Efficient Data Analysis

We have performed parallel large-scale molecular-dynamics simulations on the QSC-machine at Los Alamos. The good scalability of the SPaSM code is demonstrated together with its capability of efficient data analysis for enormous system sizes up to 19 000 416 964 particles. Furthermore, we introduce a newly-developed graphics package that renders in a very efficient parallel way a huge number of spheres necessary for the visualization of atomistic simulations. These abilities pave the way for future atomistic large-scale simulations of physical problems with system sizes on the μ-scale.

Reactive Molecular Dynamics Simulation of Graphene-Based Nanomaterials Produced by Confined Heating of Polymer

2016 ◽  
Author(s):  
Yuan Dong ◽  
Jian Lin
Keyword(s):  
Molecular Dynamics ◽  
High Performance ◽  
Large Scale ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Metal Catalyst ◽  
Processing Temperature ◽  
Scale Production ◽  
Reactive Molecular Dynamics ◽  
Laser Scribing

The graphene-based nanomaterial has great potential as catalyst and supercapacitors. In this paper we study the pyrolysis of polymers in a nanosecond time scale with the reactive molecular dynamics (MD) simulations using ReaxFF potential. It is found that the confined heating will produce graphene-like nanostructures out of two kinds of polymers: polyimide and polyether ether ketone. The peak pressure achieves above 3GPa with a processing temperature of 3000K. It indicates that the local high temperature and pressure can convert polymer to graphene-based nanomaterials without metal catalyst, which may enable large scale production of high performance electrical devices and microreactors with laser scribing method.

Molecular Dynamics Simulation on the Tension Deformation of Carbon Nanotubes

2011 ◽  
Vol 697-698 ◽  
pp. 487-490
Author(s):  
M.Y. Zhou ◽  
Yan Ling Tian ◽  
Z. Ren ◽  
H.Y. Zheng ◽  
R.B. Wei
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Single Walled Carbon Nanotubes ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
The Relationship

Molecular dynamics (MD) simulations were used to investigate the elastic properties of carbon nanotubes (CNTs). Displacements were loaded to CNTs on the tension deformation simulations. In order to better understand the relationship between Young’s modulus and the structure of the CNTs, different chiralities and diameters were involved. It is found that the Young’s modulus will be no more sensitive as in the single-walled carbon nanotubes (SWCNTs) with increasing walls. The tension deformation results also indicate that SWCNTs have better elastic property compared to multi-walled carbon nanotubes (MWCNTs).

scholarly journals High-Rate Plastic Deformation of Nanocrystalline Tantalum to Large Strains: Molecular Dynamics Simulation

2009 ◽  
Vol 633-634 ◽  
pp. 3-19 ◽  
Author(s):  
Robert E. Rudd
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Large Scale ◽  
Amorphous Solid ◽  
Md Simulations ◽  
High Rate ◽  
Dynamics Simulation ◽  
Biaxial Compression ◽  
Large Strains ◽  
Fine Grained

Recent advances in the ability to generate extremes of pressure and temperature in dynamic experiments and to probe the response of materials has motivated the need for special materials optimized for those conditions as well as a need for a much deeper understanding of the behavior of materials subjected to high pressure and/or temperature. Of particular importance is the understanding of rate effects at the extremely high rates encountered in those experiments, especially with the next generation of laser drives such as at the National Ignition Facility. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum to investigate the processes associated with plastic deformation for strains up to 100%. We use initial atomic configurations that were produced through simulations of solidification in the work of Streitz et al [Phys. Rev. Lett. 96, (2006) 225701]. These 3D polycrystalline systems have typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. This analysis technique is robust and fast, and has been used to compute the orientations on the fly during our parallel MD simulations on supercomputers. We find both dislocation and twinning processes are important, and they interact in the weak strain hardening in these extremely fine-grained microstructures.

Combustion Driven by Fragment-based Ab Initio Molecular Dynamics Simulation

2019 ◽  
Author(s):  
Liqun Cao ◽  
Jinzhe Zeng ◽  
Mingyuan Xu ◽  
Chih-Hao Chin ◽  
Tong Zhu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Large Scale ◽  
Methane Combustion ◽  
Combustion Method ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Computational Time ◽  
Combustion Mechanism ◽  
Daily Lives

Combustion is a kind of important reaction that affects people's daily lives and the development of aerospace. Exploring the reaction mechanism contributes to the understanding of combustion and the more efficient use of fuels. Ab initio quantum mechanical (QM) calculation is precise but limited by its computational time for large-scale systems. In order to carry out reactive molecular dynamics (MD) simulation for combustion accurately and quickly, we develop the MFCC-combustion method in this study, which calculates the interaction between atoms using QM method at the level of MN15/6-31G(d). Each molecule in systems is treated as a fragment, and when the distance between any two atoms in different molecules is greater than 3.5 Å, a new fragment involved two molecules is produced in order to consider the two-body interaction. The deviations of MFCC-combustion from full system calculations are within a few kcal/mol, and the result clearly shows that the calculated energies of the different systems using MFCC-combustion are close to converging after the distance thresholds are larger than 3.5 Å for the two-body QM interactions. The methane combustion was studied with the MFCC-combustion method to explore the combustion mechanism of the methane-oxygen system.

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