A Molecular Dynamics Study of Short Nanoparticle Chains under Mechanical Strain: Linear and Kinked Configurations

MRS Proceedings ◽

10.1557/proc-821-p6.4 ◽

2004 ◽

Vol 821 ◽

Author(s):

Adamos Dalis ◽

Sheldon K. Friedlander

Keyword(s):

Molecular Dynamics ◽

Mechanical Behavior ◽

High Speed ◽

Mechanical Strain ◽

Quantitative Information ◽

Atomic Scale ◽

Test Material ◽

Interatomic Potentials ◽

Stress Accommodation ◽

Nanoparticle Chains

AbstractPrevious studies in our laboratory have shown that individual nanoparticle chain aggregates (NCA) exhibit remarkable mechanical behavior when under strain inside the transmission electron microscope. NCA made of various materials (e.g. carbon, metal oxides, metals, etc.) were strained by as much as 100% when tension was applied to them. After breaking, the NCA rapidly contracted to form more compact structures. In this study, molecular dynamics (MD) computer simulations are employed to investigate, at the atomic scale, the behavior of short nanoparticle chains under strain and to obtain quantitative information of the forces involved in chain straining and fracturing. The interaction potential used is that of copper obtained with the embedded atom method (EAM). Although the methodology is generally applicable, copper was selected as a test material because reliable interatomic potentials are available. Seven single- crystal nanoparticles, each 2.452 nm in diameter, are placed in contact in two chain configurations, linear and kinked. The structures are initially relaxed adiabatically with MD steps for 225 ps, at a starting temperature of 300 K. The bonding energy between any two nanoparticles in contact ranges from about 20 eV to 30 eV at 0 K. The two relaxed chain configurations are strained along their longest dimension, to the breaking point, at strain rates spanning from 0.3 m/s to 10 m/s. We identify mechanisms of stress accommodation that lead to plastic deformation and eventually fracture for both chain configurations, linear and kinked, and we construct the corresponding stress-strain curves. The two chain configurations exhibit different mechanical behavior. Applications of our experimental and simulation studies on NCA are to the behavior of nanocomposite materials, including carbon black reinforced rubber, sampling of aggregates by high speed impactors and the formation of flexible coatings of nanoparticles.

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Comparative Studies on Water Self-Diffusivity Confined in Graphene Nanogap: Molecular Dynamics Simulation

ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2016-7962 ◽

2016 ◽

Author(s):

Mohammad Moulod ◽

Gisuk Hwang

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Surface Energy ◽

Water Transport ◽

Surface Interactions ◽

Bulk Water ◽

Water Desalination ◽

Atomic Scale ◽

Dynamics Simulation ◽

Interatomic Potentials

Fundamental understanding of the water in graphene is crucial to optimally design and operate the sustainable energy, water desalination, and bio-medical systems. A numerous atomic-scale studies have been reported, primarily articulating the surface interactions (interatomic potentials) between the water and graphene. However, a systematic comparative study among the various interatomic potentials is rare, especially for the water transport confined in the graphene nanostructure. In this study, the effects of different interatomic potentials and gap sizes on water self-diffusivity are investigated using the molecular dynamics simulation at T = 300 K. The water is confined in the rigid graphene nanogap with the various gap sizes Lz = 0.7 to 4.17 nm, using SPC/E and TIP3P water models. The water self-diffusivity is calculated using the mean squared displacement approach. It is found that the water self-diffusivity in the confined region is lower than that of the bulk water, and it decreases as the gap size decreases and the surface energy increases. Also, the water self-diffusivity nearly linearly decreases with the increasing surface energy to reach the bulk water self-diffusivity at zero surface energy. The obtained results provide a roadmap to fundamentally understand the water transport properties in the graphene geometries and surface interactions.

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Mechanical behavior comparison of spider and silkworm silks using molecular dynamics at atomic scale

Physical Chemistry Chemical Physics ◽

10.1039/c5cp06809f ◽

2016 ◽

Vol 18 (6) ◽

pp. 4814-4821 ◽

Cited By ~ 17

Author(s):

Myeongsang Lee ◽

Junpyo Kwon ◽

Sungsoo Na

Keyword(s):

Molecular Dynamics ◽

Mechanical Behavior ◽

Mechanical Characteristics ◽

Atomic Scale ◽

Serine Residue ◽

Nano Scale

Mechanical characteristics between spider and silkworm silks fibroins at nano scale are different owing to end serine residue in silkworm.

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The Molecular dynamics simulations of the mechanical behavior of nanostructured and amorphous Al80Ti15Ni5 alloy

Revista Facultad de Ingeniería Universidad de Antioquia ◽

10.17533/udea.redin.20201009 ◽

2020 ◽

Author(s):

Alexandre Melhorance Barboza ◽

Ivan Napoleão Bastos ◽

Luis César Rodríguez Aliaga

Keyword(s):

Molecular Dynamics ◽

Mechanical Behavior ◽

Molecular Dynamics Simulations ◽

Atomic Structure ◽

Amorphous Material ◽

Young Modulus ◽

Grain Boundary Sliding ◽

Deformation Mechanisms ◽

Interatomic Potentials ◽

Dynamics Simulations

Classical deformation mechanisms based on crystalline defects of metallic polycrystals are not entirely suitable to describe the mechanical behavior of nanocrystalline and glassy materials. Their inherent complexity creates a real challenge to understand the acting physical phenomena. Thus, the molecular dynamics approach becomes interesting because it allows evaluating the mechanical properties and its related atomic structure. To study the atomic structure's influence on the deformation mechanisms at the nanoscale level of the Al80Ti15Ni5 alloy, molecular dynamics simulations, and post-processing techniques were used in the present work. The results revealed a significant dependency between the Young modulus and the atomic structure. Moreover, the type of structure, i.e., nanocrystalline or amorphous, governs the deformation mechanism type. For the nanocrystalline alloy, grain boundary sliding and diffusion seem to be the dominant deformation processes followed by the less essential emissions of partial dislocations from the grain boundaries. Concerning the amorphous material, the shear transformation zones begin to form in the elastic regime evolving to shear bands, these being the main mechanisms involved in the deformation process. The results also indicate the amorphous structure as a lower limit-case of the nanocrystal. The Al80Ti15Ni5 elastic moduli values were below expectations; for this reason, the effects of unary and ternary interatomic potentials were evaluated for each element.

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Atomic-Scale Grooving on Copper: End-Milling vs. Peripheral-Milling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.565.546 ◽

2012 ◽

Vol 565 ◽

pp. 546-551 ◽

Cited By ~ 5

Author(s):

D.D. Cui ◽

Kausala Mylvaganam ◽

Liang Chi Zhang

Keyword(s):

Molecular Dynamics ◽

High Speed ◽

End Milling ◽

Molecular Dynamics Method ◽

Atomic Scale ◽

Peripheral Milling ◽

Milling Forces ◽

Dynamics Method

This paper investigates the high speed nano-grooving on mono-crystalline copper by nano-end-milling and nano-peripheral-milling. The molecular dynamics method was used for simulation. The milling forces and grooving quality were analysed in detail. The comparison showed that peripheral-milling requires a higher force, but the milled groove has a better quality. Nevertheless, both the milled groove subsurfaces are free of major dislocations.

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