Wrinkling in Graphene Subjected to Gradient Tension

NANO ◽  
2015 ◽  
Vol 10 (03) ◽  
pp. 1550037 ◽  
Author(s):  
Jianzhang Huang ◽  
Qiang Han
Keyword(s):  
Molecular Dynamics ◽  
Single Layer ◽  
Md Simulations ◽  
Area Ratio ◽  
Single Layer Graphene ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Displacement Direction ◽  
Effects Of Temperature ◽  
Plane Displacement

In the present study, the initiation and evolution mechanisms of wrinkles in a square single layer graphene sheet (SLGS) under gradient tensile displacements are investigated based on molecular dynamics (MD) simulations. The mechanism of wrinkling process is elucidated by studying the atomic out-of-plane displacements development of the key atoms in SLGS. It reveals that the loading and boundary conditions play dominant roles in the wrinkling deformation of graphene. The dependences of the wrinkling amplitude, wavelength, out-of-plane displacement, direction angle and wrinkling area ratio on the applied gradient tensile displacements are obtained. The effects of temperature, size of graphene and loading grads on graphene wrinkling are investigated.

scholarly journals A Molecular Dynamics Study on Wrinkles in Graphene with Simply Supported Boundary under In-Plane Shear

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jianzhang Huang ◽  
Qiang Han
Keyword(s):  
Molecular Dynamics ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Propagation Process ◽  
Plane Shear ◽  
Simply Supported ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Formation And Evolution ◽  
Dynamics Simulations

The formation and evolution mechanisms of wrinkling in a rectangular single layer graphene sheet (SLGS) with simply supported boundary subjected to in-plane shear displacements are investigated using molecular dynamics simulations. Through investigating the out-of-plane displacements of the key point atom, we clarify the wrinkling growth and propagation process. Our results show that the boundary condition plays important roles in the wrinkling deformation. And the dependence of wrinkling parameters on the applied shear displacements is captured. Based on the elasticity theory, the formation mechanism of graphene wrinkling is revealed from the viewpoint of elastic energy. The effects of aspect ratio of graphene, temperature, and loading velocity on graphene wrinkling parameters and patterns are also investigated.

Thermal Conductivity Reduction in Few-Layer Graphene

2011 ◽  
Author(s):  
Dhruv Singh ◽  
Jayathi Y. Murthy ◽  
Timothy S. Fisher
Keyword(s):  
Thermal Conductivity ◽  
Weak Coupling ◽  
Phonon Scattering ◽  
Single Layer ◽  
Acoustic Mode ◽  
Single Layer Graphene ◽  
Boltzmann Transport ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Few Layer Graphene

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. The highly restrictive selection rule that leads to a high thermal conductivity of ZA phonons in single-layer graphene is only weakly broken with the addition of multiple layers, and ZA phonons still dominate thermal conductivity. We also find that the decrease in thermal conductivity is mainly caused by decreased contributions of the higher-order overtones of the fundamental out-of-plane acoustic mode. Moreover, the extent of reduction is largest when going from single to bilayer graphene and saturates for four layers. The results compare remarkably well over the entire temperature range with measurements of of graphene and graphite.

The effect of Nanopores Geometry on Desalination of Single-layer Graphene-based Membranes: A Molecular Dynamics Study

2021 ◽  
pp. 116749
Author(s):  
Amirhossein Bagheri Sarvestani ◽  
Alireza Chogani ◽  
Maryam Shariat ◽  
Ali Moosavi ◽  
Hamid Kariminasab
Keyword(s):  
Molecular Dynamics ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Layer Graphene

scholarly journals Thermal Resistance across Interfaces Comprising Dimensionally Mismatched Carbon Nanotube-Graphene Junctions in 3D Carbon Nanomaterials

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jungkyu Park ◽  
Vikas Prakash
Keyword(s):  
Carbon Nanotube ◽  
Thermal Resistance ◽  
Carbon Nanomaterials ◽  
Single Layer ◽  
Unit Cell ◽  
Single Layer Graphene ◽  
Interfacial Thermal Resistance ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Plane Direction

In the present study, reverse nonequilibrium molecular dynamics is employed to study thermal resistance across interfaces comprising dimensionally mismatched junctions of single layer graphene floors with (6,6) single-walled carbon nanotube (SWCNT) pillars in 3D carbon nanomaterials. Results obtained from unit cell analysis indicate the presence of notable interfacial thermal resistance in the out-of-plane direction (along the longitudinal axis of the SWCNTs) but negligible resistance in the in-plane direction along the graphene floor. The interfacial thermal resistance in the out-of-plane direction is understood to be due to the change in dimensionality as well as phonon spectra mismatch as the phonons propagate from SWCNTs to the graphene sheet and then back again to the SWCNTs. The thermal conductivity of the unit cells was observed to increase nearly linearly with an increase in cell size, that is, pillar height as well as interpillar distance, and approaches a plateau as the pillar height and the interpillar distance approach the critical lengths for ballistic thermal transport in SWCNT and single layer graphene. The results indicate that the thermal transport characteristics of these SWCNT-graphene hybrid structures can be tuned by controlling the SWCNT-graphene junction characteristics as well as the unit cell dimensions.

scholarly journals Nanomechanics of graphene

2018 ◽  
Vol 6 (2) ◽  
pp. 324-348 ◽  
Author(s):  
Yujie Wei ◽  
Ronggui Yang
Keyword(s):  
Plane Deformation ◽  
Single Layer ◽  
High Strength ◽  
Review Article ◽  
Single Layer Graphene ◽  
Bending Rigidity ◽  
Mechanical Behaviors ◽  
Carbon Allotropes ◽  
Layer Graphene ◽  
Out Of Plane

Abstract The super-high strength of single-layer graphene has attracted great interest. In practice, defects resulting from thermodynamics or introduced by fabrication, naturally or artificially, play a pivotal role in the mechanical behaviors of graphene. More importantly, high strength is just one aspect of the magnificent mechanical properties of graphene: its atomic-thin geometry not only leads to ultra-low bending rigidity, but also brings in many other unique properties of graphene in terms of mechanics in contrast to other carbon allotropes, including fullerenes and carbon nanotubes. The out-of-plane deformation is of a ‘soft’ nature, which gives rise to rich morphology and is crucial for morphology control. In this review article, we aim to summarize current theoretical advances in describing the mechanics of defects in graphene and the theory to capture the out-of-plane deformation. The structure–mechanical property relationship in graphene, in terms of its elasticity, strength, bending and wrinkling, with or without the influence of imperfections, is presented.

Adsorption and Conformational Evolution of Alpha-Helical BSA Segments on Graphene: A Molecular Dynamics Study

2016 ◽  
Vol 08 (02) ◽  
pp. 1650021 ◽  
Author(s):  
Jingjie Yeo ◽  
Yuan Cheng ◽  
You Ting Han ◽  
Yingyan Zhang ◽  
Guijian Guan ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Conformational Dynamics ◽  
Single Layer ◽  
Md Simulations ◽  
Single Layer Graphene ◽  
Strong Interactions ◽  
Helical Structures ◽  
Single Segment ◽  
Helical Content ◽  
The Individual

Molecular dynamics (MD) simulations are performed to investigate the adsorption mechanics and conformational dynamics of single and multiple bovine serum albumin (BSA) peptide segments on single-layer graphene through analysis of parameters such as the root-mean-square displacements, number of hydrogen bonds, helical content, interaction energies, and motions of mass center of the peptides. It is found that for the single segment system, destabilization of the helical structures in the form of the reduction in hydrogen bond numbers and [Formula: see text]-helical content of the peptides occurred due to the strong interactions between BSA peptides and graphene. Similar destabilizations of the individual segments in the multi-segment system can occur as well, albeit with greater complexity and in a lesser degree due to the inter-segment interactions. Alleviation of decreases in the total helical content in the multi-segment system indicates protective capabilities of segment–segment interactions, which weaken their interactions with graphene. Diffusive motion upon adsorption of the segment(s) onto graphene is found to be highly confined, and the distance traversed by each segment in the multi-segment system was more significant than that in the single segment system, similarly attributable to reductions in their interactions with graphene due to inter-segment interactions.

scholarly journals DNA Detection Using Programmed Bilayer Nanopores

2018 ◽  
Author(s):  
Ramkumar Balasubramanian ◽  
Sohini Pal ◽  
Himanshu Joshi ◽  
Banani Chakraborty ◽  
Akshay Naik ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Single Layer ◽  
Dna Origami ◽  
Single Layer Graphene ◽  
Specific Interactions ◽  
Residence Times ◽  
Dna Translocation ◽  
Pore Region ◽  
Layer Graphene ◽  
Dynamics Simulations

<p>Pore-functionalization has been explored by several groups as a strategy to control DNA translocation through solid-state nanopores. Here we present a hybrid nanopore system consisting of single-layer graphene and a DNA origami layer to achieve base-selective control of DNA translocation rate through aligned nanopores of the two layers. This is achieved by incorporating unpaired dangling bases called overhangs to the origami near the pore region. Molecular dynamics simulations were used to optimize the design of the origami nanopore and the overhangs. Specifically, we considered the influence of the number and spatial distribution of overhangs on translocation times. The simulations revealed that specific interactions between the overhangs and the translocating single stranded DNA resulted in base-specific residence times. <b></b></p>

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