We have developed a model for the calculation of van der Waals force for layered systems with axial symmetry. Our result can be applied to compute the cohesion of a carbon nanotube to a substrate, the cohesion between nanotubes, and between shells of multiwall nanotubes. We have obtained unusal power laws for the distance dependence of the many-body van der Waals potential.

We investigate the role of weak clamping forces, typically assumed to be infinite, in carbon nanotube mechanical resonators. Due to these forces, we observe a hysteretic clamping and unclamping of the nanotube device that results in a discrete drop in the mechanical resonance frequency on the order of 5-20 MHz, when the temperature is cycled between 340 and 375 K. This instability in the resona...

Van der Waals interactions have a fundamental role in biology, physics and chemistry, in particular in the self-assembly and the ensuing function of nanostructured materials. Here we utilize an efficient microscopic method to demonstrate that van der Waals interactions in nanomaterials act at distances greater than typically assumed, and can be characterized by different scaling laws depending ...

in this paper, the radial breathing mode (rbm) frequencies of multi-walled carbon nanotubes (mwcnts) are  obtained based on the multiple-elastic thin shell model. for this purpose, mwcnt is considered as a multiple concentric elastic thin cylindrical shells, which are coupled through van der waals (vdw) forces between two adjacent tubes. lennard-jones potential is used to calculate the vdw forc...

Van der Waals interactions between flat surfaces in uniaxial anisotropic media are investigated in the nonretarded limit. The main focus is the effect of nonzero tilt between the optical axis and the surface normal on the strength of the van der Waals attraction. General expressions for the van der Waals free energy are derived using the surface mode method and the transfer-matrix formalism. To...

Among the intermolecular interactions, the Casimir and van der Waals forces are the most important forces that highly affect the behavior of nanostructures. This paper studies the effect of such forces on the adhesion of cantilever freestanding nanostructures. The nanostructures are made of a freestanding nano-beam which is suspended between two upper and lower conductive surfaces. The linear s...

The accurate description of van der Waals forces within density functional theory is currently one of the most active areas of research in computational physics and chemistry. Here we report results on the structural and energetic properties of graphite and hexagonal boron nitride, two layered materials where interlayer binding is dominated by van der Waals forces. Results from several density ...

A modified two-dimensional van der Waals equation model was proposed for the prediction of multicomponent gas-solid adsorption isotherms from corresponding single-component adsorption equilibrium data. The model was used to predict adsorption isotherms of CO-CO2 mixtures and CO2-N2 mixtures on Cu(I)-NaY zeolite. Experimental adsorption equilibrium data of the two systems were compared with resu...

In this study a simple and general chemical association theory is introduced. The concept of infinite equilibrium model is re-examined and true mole fractions of associated species are calculated. The theory is applied to derive the distribution function of associated species. As a severe test the application of presented theory to the van der Waals mixture model is introduced in order to p...

carbon nanotube is investigated based on an elastic multi-layer shell model with van der Waals interaction taken into consideration. The multi-walled carbon nanotube is described as an individual elastic shell and the interlayer friction is negligible between the inner and outer tubes in the proposed model. And the Donnell equations of cylindrical shells are employed to describe the nonlinear b...