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In molecular physics and chemistry, the van der Waals force (sometimes van der Waals' force) is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds , these attractions do not result from a chemical electronic bond ; [ 2 ] they are comparatively weak and therefore more susceptible to disturbance.
Interaction energy of an argon dimer.The long-range section is due to London dispersion forces. London dispersion forces (LDF, also known as dispersion forces, London forces, instantaneous dipole–induced dipole forces, fluctuating induced dipole bonds [1] or loosely as van der Waals forces) are a type of intermolecular force acting between atoms and molecules that are normally electrically ...
DLVO theory is the combined effect of van der Waals and double layer force. For the derivation, different conditions must be taken into account and different equations can be obtained. [ 13 ] But some useful assumptions can effectively simplify the process, which are suitable for ordinary conditions.
Van der Waals forces originate from the interactions between induced, permanent or transient electric dipoles. In comparison with chemisorption , in which the electronic structure of bonding atoms or molecules is changed and covalent or ionic bonds form, physisorption does not result in changes to the chemical bonding structure.
Description of van der Waals forces by the Lennard-Jones 6–12 potential introduces inaccuracies, which become significant at short distances. [1] Generally a cutoff radius is used to speed up the calculation so that atom pairs which distances are greater than the cutoff have a van der Waals interaction energy of zero.
Non-covalent interactions can be classified into different categories, such as electrostatic, π-effects, van der Waals forces, and hydrophobic effects. [3] [2] Non-covalent interactions [4] are critical in maintaining the three-dimensional structure of large molecules, such as proteins and nucleic acids.
Van der Waals began work by trying to determine a molecular attraction that appeared in Laplace's theory of capillarity, and only after establishing his equation he tested it using Andrews' results. [35] [36] By 1877 sprays of both liquid oxygen and liquid nitrogen had been produced, and a new field of research, low temperature physics, had ...
The silicon direct bonding is based on intermolecular interactions including van der Waals forces, hydrogen bonds and strong covalent bonds. [2] The initial procedure of direct bonding was characterized by a high process temperature.