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Molecular structural mechanics is implemented to model vibrational behavior of defect free single-layered graphene sheets (SLGSs) at constant temperature. To mimic these two-dimensional layers, zigzag and armchair models with cantilever and bridge boundary conditions are adopted. Fundamental frequencies of these nano structures are calculated, and it is perceived that they are independent of the chirality and aspect ratio. Effects of point mass and atomistic dust on the fundamental frequencies are also considered in order to investigate the possibility of using SLGSs as sensors. Results of exhibit the principle frequencies are highly sensitive to the added mass in the order of 10-6fg.... 

Nonequilibrium molecular dynamics simulations are used to study the motion of a C60 molecule on a graphene sheet subjected to a temperature gradient. The C60 molecule is actuated and moves along the system while it just randomly dances along the perpendicular direction. Increasing the temperature gradient increases the directed velocity of C60. It is found that the free energy decreases as the C60 molecule moves toward the cold end. The driving mechanism based on the temperature gradient suggests the construction of nanoscale graphene-based motors  

Molecular structural mechanics is implemented to model the vibrational behavior of defect-free single-layered graphene sheets (SLGSs) at constant temperature. To mimic these two-dimensional layers, zigzag and armchair models with cantilever and bridge boundary conditions are adopted. Fundamental frequencies of these nanostructures are calculated, and it is perceived that they are independent of the chirality and aspect ratio. The effects of point mass and atomistic dust on the fundamental frequencies are also considered in order to investigate the possibility of using SLGSs as sensors. The results show that the principal frequencies are highly sensitive to an added mass of the order of 1 0-... 

In this paper, the bending modulus of a multi-layered graphene sheet is investigated using a geometrically based analytical approach. For this purpose, a bending potential energy is derived, based on the van der Waals interactions of atoms belonging to the two neighboring sheets of a double-layered graphene sheet. The inter-atomic spacing between the adjacent layers is determined along the line of action of the applied bending moments. The bending potential of the double-layered sheet is calculated by summing up the potentials at discrete hexagons over the length and width of the sheet. A multi-layered graphene sheet is considered as consisting of many stacking double-layers. It is observed... 

In this article, the bending stiffness of a double-layered graphene sheet is investigated using a geometrically-based analytical approach. The analysis is based on the van der Waals interactions of atoms belonging to two neighboring sheets. The inter-atomic spacing between the adjacent layers is geometrically determined when the sheet is applied by a couple of moments in the opposite sides. The bending potential energy is obtained by summing up the potentials at discrete hexagons over the length and width of the sheet. It is observed that the bending stiffness of a double-layered graphene sheet does not depend on the length of the sheet and be a material property for the associated sheet.... 

Carbon nanostructures such as carbon nanotubes (CNTs) and graphene sheets have attracted great attention due to their exceptionally high strength and elastic strain. These extraordinary mechanical properties, however, can be affected by the presence of defects in their structures. When a material contains multiple defects, it is expected that the stress concentration of them superposes if the separation distances of the defects are low, which causes a more reduction of the strength. On the other hand, it is believed that if the defects are far enough such that their affected areas are distinct, their behavior is similar to a material with single defect. In this article, molecular dynamics... 

This work presents a procedure for functionalization of graphene sheets from edges by polyglycerol. Hyperbranched polyglycerol with a bi-dentate aromatic segment in its focal point was synthesized and used to sandwich graphene sheets from the cut-edges. Due to the hydrophobicity of the flat surface of the edge-functionalized graphenes and hydrophilicity of their edges, they changed their conformation from the extended- to the closed-state and formed nanocapsules in aqueous solutions. Spectroscopy and microscopy evaluations showed that the average size for nanocapsules is 300 nm. They were able to encapsulate hydrophobic molecules such as doxorubicin in aqueous solutions with a high loading... 

In this paper, the simulation of biomolecules manipulation using molecular dynamics (MD) is studied. In order to investigate the manipulation behavior, we have used the ubiquitin as biomolecule, a single-walled carbon nanotube (SWCNT) as manipulation probe, a two-layer graphene sheet as substrate. Along this line, a series of simulations are conducted to study the effects of different conditions on the success of manipulation process. These conditions include tip diameter, vertical gap between the tip and substrate, initial orientation of protein, and the tip position with respect to the biomolecule  

Because of its unique properties, graphene has attracted the attentions of many academic research groups and recently, the industry. One of the promising applications of the graphene is in micro/nano-sensors, e.g. using it as a pressure sensor. To use it in mechanical-based nano-sensors, it is very important to investigate the mechanical behavior of the nano-sized graphene sheet and its sensitivity to the medium changes applied on its faces. In this work, we use the molecular dynamics MD method and simulate the behavior of graphene sheet under differential water pressure influences. In this regard, a square straight monolayer graphene sheet is placed as a separator diaphragm between two... 

Molecular structural mechanics is implemented to model vibrational behavior of defect free single-layered graphene sheets (SLGSs) at constant temperature. To mimic these two-dimensional layers, zigzag and armchair models with cantilever and bridge boundary conditions are adopted. Fundamental frequencies of these nano structures are calculated, and it is perceived that they are independent of the chirality and aspect ratio. Effects of point mass and atomistic dust on the fundamental frequencies are also considered in order to investigate the possibility of using SLGSs as sensors. Results of exhibit the principle frequencies are highly sensitive to the added mass in the order of 10-6 fg.... 

In this paper, nanoscale vibrational analysis of a multi-layered graphene sheet embedded in an elastic medium is investigated and the corresponding natural frequencies and the associated modes are determined. The modeling is based on the fact that the elastic moduli of a graphene sheet in two perpendicular orientations are different, so the plate is considered to be anisotropic. The graphene layers stacking at the top of each other bond with carbon-carbon van der Waals forces between two adjacent ones. Also, the whole multi-layered graphene sheet is influenced by polymer-carbon van der Waals forces from the surrounding elastic medium. © 2005 Elsevier Ltd. Al rights reserved  

In this paper, the molecular structural mechanics method is employed to calculate the mechanical properties of a double-layered carbon graphene sheet more accurately. For this purpose, covalent bonds are modeled using nonlinear beam elements and van der Waals interactions are replaced by nonlinear truss elements. Morse potential and Lennard-Jones potential equations are used to simulate the covalent bonds and van der Waals interactions, respectively. For each atom, van der Waals forces are considered with respect to all the other atoms located in its cut-off radius. In addition to in-plane mechanical properties of single and double-layered graphene sheets some out-of-plane properties like... 

Dynamic and static fracture properties of Graphene Sheets (GSs) and Carbon nanotubes (CNTs) with different sizes are investigated based on an empirical inter-atomic potential function that can simulate nonlinear large deflections of nanostructures. Dynamic fracture of GSs and CNTs are studied based on wave propagation analysis in these nanostructures in a wide range of strain-rates. It is shown that wave propagation velocity is independent from strain-rate while dependent on the nanostructure size and approaches to 2.2×10 4m/s for long GSs. Also, fracture strain shows extensive changes versus strain-rate, which has not been reported before. Fracture stress is determined as 115GPa for GSs and...