Van der Waals binding

Since most SWNTs have diameters in the range of 1 -2 nm, we can expect them to remain cylindrical when they form cables. The stiffness constant of the cable structures will then be the sum of the stiffness constants of the SWNTs. However, just as with MWNTs, the van der Waals binding between the tubes limits tensile strength unless the ends of all the tubes can be fused to a load. In the case of bending, a more exact... 

We should mention here that even for the diatomic molecule Hgj, which is domi-nantely bound via van der Waals binding, our calculation in terms of the Xa-ap-proximation is valid to some extent. At least it results in a binding of the two atoms, which is non-trivial. The largest system so far is Hgj, which we calculated in terms of a total energy calculation . The two dimensional potential energy surface with its relatively flat minimum is presented in Fig. 4. 

Wong [38] also found that the larger trinuclear dyes, analogous to those of Table 6-8, have a greater affinity for hair than the simple mononuclear dyes undoubtedly arising from a larger number of polar and Van der Waals binding sites between dye and hair. 

Owing to the smooth, hydrophobic surfaces and a van der Waals binding energy of 500eV pm of tube-tube contact, pristine CNTs aggregate and form parallel bundles... 

The application of the analytical identity (3.44) to the van der Waals binding energy in crystals at zero temperature was first reported by Mahan in 1965 [34]. Van Kampen et al. used the same theorem in investigations on the van der Waals energy between half-spaces [35]. The extension to include finite temperatures is due to Ninham et al. [36]. 

We would finally like to note that the attraction formulae (6) and (19) cannot be used wholly without care. In this way we could be led to believe that the chemical binding of H2 can be seen as a van der Waals binding, since from a = 0.66 10 , hv = 13.5 V, iJo — 0.75 A we compute... 

In the scheme of OiR the hydrophobic region around the anionic group is shown as an area of Van der Waals binding (Fig. 8). This hydrophobic region is adapted to interact with the methyl groups attached to the nitrogen atom in ACh. 

A variety of physical properties of several liquids and polymers can be quantitatively described by considering a crystalline arrangement of molecules or other volume elements bound by non-directional forces. In some cases we propose that the intermolec-ular forces in the liquid or solid under question are simply due to van der Waals interactions. In those cases we demonstrate that physical properties such as surface energy cohesive strength compressibility thermal expansion and work of vaporization can be calculated from atomic constants and related to one another by the proposed model. In the case of other liquids and polymers intermolecular forces cannot be described in terms of van der Waals binding alone and other (directional) forces such as dipole-dipole binding must be included. It will be shown that a variety of the calculated properties favorably compare with experimental results. 

The elastic moduli of isotropic poljrmers represent the interchain elasticity and reflect the properties of the weak van der Waals binding potentials ... 

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