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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 symmetric; that is, the electrons are ...
The London–van der Waals forces are related to the Casimir effect for dielectric media, the former being the microscopic description of the latter bulk property. The first detailed calculations of this were done in 1955 by E. M. Lifshitz. [15] [16] A more general theory of van der Waals forces has also been developed. [17] [18]
Fritz Wolfgang London (March 7, 1900 – March 30, 1954) was a German born physicist and professor at Duke University. His fundamental contributions to the theories of chemical bonding and of intermolecular forces (London dispersion forces) are today considered classic and are discussed in standard textbooks of physical chemistry.
The source of adhesive forces, according to the dispersive adhesion mechanism, is the weak interactions that occur between molecules close together. These interactions include London dispersion forces, Keesom forces, Debye forces and hydrogen bonds. Individually, these attractions are not very strong, but when summed over the bulk of a material ...
An intermolecular force (IMF; also secondary force) is the force that mediates interaction between molecules, including the electromagnetic forces of attraction or repulsion which act between atoms and other types of neighbouring particles, e.g. atoms or ions. Intermolecular forces are weak relative to intramolecular forces – the forces which ...
DLVO theory is a theory of colloidal dispersion stability in which zeta potential is used to explain that as two particles approach one another their ionic atmospheres begin to overlap and a repulsion force is developed. [1] In this theory, two forces are considered to impact on colloidal stability: Van der Waals forces and electrical double ...
The Van der Waals forces are effective only up to several hundred angstroms. When the interactions are too far apart, the dispersion potential decays faster than 1 / r 6 ; {\displaystyle 1/r^{6};} this is called the retarded regime, and the result is a Casimir–Polder force .
As molecules come closer, this attractive force arises due to the ordering of these dipoles; like in the case of magnets that align and attract each other as they approach. [7] This also implies that any surface would experience a van der waals attraction. In bilayers, the form taken by van der Waals interaction potential V VDW is given by [8]