Solvation of graphene sheets vs. dimerization: A theoretical study

Thermodynamic stability of graphene against stacking in the gas phase and in different solvents (N-methyl-2-pyrrolidone), dimethyl sulfoxide, and water) has been investigated using the semi-empirical PM6 method combined with supermolecular approach, and with Periodic Boundary Conditions using Density Functional Theory in conjunction with the Perdew-Burke-Erzernhof functional. In the case of a supermolecular approach, the effect of the ratio of the edge and the center part on the solvation enthalpy has also been investigated.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Effect of structural defects and chemical functionalisation on the intrinsic mechanical properties of graphene

Due to its unique mechanical properties, graphene can be applied for reinforcement in nanocomposites. We analyse the Young's modulus of graphene at the semi-empirical PM6 level of theory. The internal forces are calculated and the Young's modulus is predicted for a finite graphene sheet when external strain is applied on the system. These results are in a good agreement with theoretical and experimental results from the literature giving values of about 1 TPa for the Young's modulus. Stress-strain curves are computed for elongation up to 20%. In addition, the influence of the presence of a single vacancy, as well as for oxygenation of a vacancy, on the mechanical properties of graphene has been analysed. Our results indicate that when applying the deformation locally onto the system, higher local stress can be induced, as confirmed by Finite Element Analysis. Also, the presence of structural defects in the system will stiffen the system upon low strain, but reduces the elastic limit from more than 20% strain for pristine graphene to less than 10% strain when defects are present. © the Owner Societies 2013.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Solvation of graphene sheets vs. dimerization: A theoretical study

1058-1063Thermodynamic stability of graphene against stacking in the gas phase and in different solvents (N-methyl-2-pyrrolidone),<span style="mso-fareast-font-family: " ms="" mincho";mso-ansi-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US"> dimethyl sulfoxide, and water) has been investigated using the semi-empirical PM6 method combined with supermolecular approach, and with Periodic Boundary Conditions using Density Functional Theory in conjunction with the Perdew-Burke-Erzernhof functional. In the case of a supermolecular approach, the effect of the ratio of the edge and the center part on the solvation enthalpy has also been investigated. </span

Theoretical investigation of the intrinsic mechanical properties of single- and double-layer graphene

In this study, the Youngs and flexural moduli of single- and double-layer graphene have been theoretically investigated using periodic boundary condition (PBC) density functional theory (DFT) with the PBE, HSE06 H, and M06L functionals in conjunction with the 6-31G* and the 3-21G basis sets. The unit-cell size and shape dependence as well as the directional dependencies of the mechanical properties have also been investigated. Additionally, the calculated stretching and flexural strain-stress curves are reported. Finally, finite-element simulations have been performed so as to find a homogeneous equivalent isotropic transverse material for single-layer graphene, in order to reproduce mechanical behavior in both tensile and bending sollicitations. © 2012 American Chemical Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe