In this study, the free vibration behavior of orthotropic rectangular graphene sheet embedded in an elastic medium under biaxial pre-load is studied. Using the nonlocal elasticity theory, the governing equation is derived for single-layered graphene sheets (SLGS). Differential quadrature method (DQM) has been used to solve the governing equations for various boundary conditions. To verify the a...

Edge-carboxylated graphite (ECG) was produced by grinding pristine graphite in a planetary ball-mill machine. Transmission electron microscope was used to confirm the layers of graphene in ECG. The elemental analyses showed that the oxygen contents are different between ECG samples. The vibrational analysis of singleand five-layered graphene was conducted using finite element method within ANSY...

We present a fabrication method producing large and flat graphene flakes that have a few layers down to a single layer based on substrate bonding of a thick sample of highly oriented pyrolytic graphite (HOPG), followed by its controlled exfoliation down to the few to single graphene atomic layers. As the graphite underlayer is intimately bonded to the substrate during the exfoliation process, t...

In this paper, an atomistic based finite element model is developed to investigate the influence of topological defects on mechanical properties of graphene. The general in-plane stiffness matrix of the hexagonal network structure of graphene is found. Effective elastic modulus of a carbon ring is determined from the equivalence of molecular potential energy related to stretch and angular defor...

Graphene, a flat monolayer of carbon atoms tightly packed into a two-dimensional honeycomb lattice, has attracted a great deal of attention in recent years for potential applications in many technological fields, such as nanoelectronics, nanocomposites, and hydrogen supercapacitors. One possible route to harnessing these properties would be to incorporate graphene sheets into composite material...

The synthesis of single-wall carbon nanotubes of desired diameters and chiralities is critical to the design of nanoscale electronic devices with desired properties. The existing methods are based on self-assembly, therefore lacking control over the diameters and chiralities. The present work reports a direct route for rolling graphene. Specifically, we found that the electrostatic deposition o...

Introduction Graphene oxide is the liquid oxidation of graphite powder, and consists of a single atomic carbon network derivitized by phenol hydroxyl and epoxide groups on the basal plane and carboxylic acid groups at the edges[1, 2]. The chemical functionalization breaks the extended π−π conjugation of graphene, resulting in an insulating material. However the conductivity may be partially res...

In the present study, potential of finite element based molecular structural mechanics (MSM) for evaluating stress concentration factor of single-layered graphene sheets (SLGSs) with elliptical vacancies is successfully addressed. The MSM approach mimics the interatomic forces of the nanostructure by defining an equivalent frame structure containing beam elements. To obtain the mechanical and c...

In this paper, it is tried to find an approximate single layer equivalent for multi-layer graphene sheets based on third order non-local elasticity theory. The plates are embedded in two parameter Winkler-Pasternak elastic foundation, and also the thermal effects are considered. A uniform transverse load is imposed on the plates. Applying the non-local theory of Eringen based on third order she...

This paper addresses the influence of boundary conditions and small-scale effect on the free vibration of nano-plates using molecular dynamics (MD) and nonlocal elasticity theory. Based on the MD simulations, Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) is used to obtain fundamental frequencies of single layered graphene sheets (SLGSs) which modeled in this paper as the mo...