Van der Waals (VDW) interactions are probably the most basic type of interaction imaginable Any two molecules experience Van der Waals interactions Even macroscopic surfaces experience VDW interactions, but more of this later The physical process that leads to Van der Waals interactions is clear, but it is difficult to
3 nm the forces are slightly less and appear to be dominated by the van der Waals properties of the monolayers themselves 1 INTRODUCTION The nature of van der Waals forces The van der Waals forces between any two atoms or molecules may be separated into orientation, induction and dispersion forces Orientation forces arise only in the
van der Waals force, the basis for Hamaker’s treatment, did not take the ?niteness of the speed of light (retardation effects) into account, from the outset it pertained only for small distances For large separations between the macro-scopic bodies, retardation effects come into play and a more general theory of the vdW force is needed
Letters, that the forces are, in fact, repulsive when they take place under confinement The ubiquitous van der Waals force was first explained by the German-American physicist Fritz London in 1930 Using quantum mechanics, he proved the purely attractive nature of the van der Waals force for any two molecules interacting in free space
proposed that relatively weak, isotropic van der Waals (vdW) forces are essential for understanding the properties of liquid water and ice This insight was derived from ab initio computer simulations, which provide an unbiased description of water at the atomic level and yield information on the underlying molecular forces However,
forces are known as van der Waals or dispersion forces[3] The signi?cance of the ubiquitous van der Waals attractive force on the strength and properties of the bonding between ?bres in a paper sheet is still relatively unknown The strength of the van der Waals interaction can be predicted if the system Hamaker constant (A) is known[4]
van der Waals approach, named after the Dutch scientist Johannes Diderik van described as dipole-dipole interactions, called Keesom interaction energies
(a) We define precisely what we mean by a van der Waals force and, to put our (b) We give a description of the formulae of Lifshitz applicable to thin films