current paper focuses on investigating deformation mechanism of
graphene sheets in a graphene reinforced polyethylene (Gn–PE)
nanocomposite. Classical molecular dynamics (MD) simulation was
conducted on large Gn–PE systems. Different spatial arrangements of
graphene sheets were considered in order to study the effect of nonlocal
interaction among the graphenes. In all the cases 5% weight
concentration of graphene was considered in order to prepare atomistic
models for Gn–PE. As expected, graphene seemed to enhance the overall
Young’s modulus and tensile strength of the Gn–PE nanocomposite.
Hydrogenation-Assisted Graphene Origami and Its Application in Programmable Molecular Mass Uptake, Storage, and Release
Shuze Zhu and Teng Li, ACS Nano, published online ASAP (2014)
In armchair graphene sheets, crack propagates perpendicular to the applied strain, whereas crack propagation in zigzag sheets occurs at an angle to the straining direction. This occurs due to different bond structure along armchair and zigzag directions as shown in Fig. 1. Videos 1 and 2 show the fracture of armchair and zigzag sheets, respectively.
Fig. 1: Armchair and zigzag directions of graohene
In this paper we attempt to answer two questions on graphene from a mechanic’s viewpoint: why does this one-atom-thick monolayer have finite bending stiffness to ensure its stability? and what is its wrinkle mechanism? As for the first question, it is found that the repulsive residual internal moment in the bond angle can lead to a nonzero bending stiffness, which makes the graphene flat. Together with long-range attraction among atoms, such as van der Waals forces, a graphene prefers to have a self-buckling wrinkled configuration with many waves. The paper can be found at http://dx.doi.org/10.1115/1.4024178
A post-Doc position is available on a project on Ensemble Monte Carlo simulations of graphene for power electronics applications for studying the effect of boundary scattering of charge carriers in graphene nanoribbons. The project is sponsored by the Office of Naval Research- global (ONR) - Department of Defense (DOD)- U.S. Navy.
This is a joint a research project between the Electronic Packaging Laboratory (EPL) at the State University of New York at Buffalo and the Nanotechnology Research Laboratory at the University of Tabuk, Saudi Arabia.
I am glad to share my papers on MD simulation and multiscale moldeling of polymer based nanocomposites.
MD simulation of graphene-epoxy nanocomposites:
Calculation of coefficient of thermal expansion of graphene using MD simulations with various thermostatsSubmitted by Nuwan Dewapriya on Fri, 2013-08-16 11:31.
Influence of temperature and free edges on the mechanical properties of graphene (2013) Modelling Simul. Mater. Sci. Eng. 21Submitted by Nuwan Dewapriya on Tue, 2013-08-13 00:43.
I would like to share with you my first paper in a SCI journal: doi:10.1088/0965-0393/21/6/065017
How Graphene Slides: Measurement and Theory of Strain-Dependent Frictional Forces between Graphene and SiO2Submitted by Harold S. Park on Thu, 2013-05-02 12:53.
Several recent papers have reported measurements of adhesion energy between graphene and other materials (e.g., Si/SiOx and copper) [1-3]. Like thin films, many experimental methods may be adopted to measure the interfacial properties of graphene, such as the pressurized blister test  and the double-cantilever beam test . The challenges lie in the handling of atomically thin membranes and analysis/interpretation of the data.
Nanoscale Interfacial Friction and Adhesion on Supported versus Suspended Monolayer and Multilayer GrapheneSubmitted by Teng Li on Wed, 2013-01-09 07:14.
The mechanical behavior of mono- and multi- layered graphene and carbon nanotube (CNT) systems has attracted great attention over the last decade because of their importance in nano-science and nanotechnology.
We have presented a new bulk atomistic-based continuum model for layered crystalline materials made out of two- dimensional crystalline sheets. Such systems are emerging as a new family of materials with tunable and exceptional properties (Novoselov K., 2011, Nobel lecture: Graphene: materials in the flatland. Rev. Mod. Phys. 83, 837-849), but here we particularize the model to multi-layer graphene systems, including multi- walled carbon nanotubes (MWCNTs).