Boris Vladimirovich Derjaguin (or Deryagin; russian: Бори́с Влади́мирович Деря́гин) (9 August 1902 in

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 millio ...

– 16 May 1994) was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nation ...

and

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

n chemist. As a member of the

Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across ...

, he laid the foundation of the modern science of colloids and

surfaces A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. Surface or surfaces may also refer to: Mathematics *Surface (mathematics), a generalization of a plane which needs not be flat * Sur ...

. An epoch in the development of the physical chemistry of colloids and surfaces is associated with his name. Derjaguin became famous in scientific circles for his work on the stability of colloids and thin films of liquids which is now known as the

DLVO theory The DLVO theory (named after Boris Derjaguin and Lev Landau, Evert Verwey and Theodoor Overbeek) explains the aggregation of aqueous dispersions quantitatively and describes the force between charged surfaces interacting through a liquid medium ...

, after the initials of its authors: Derjaguin, Landau, Verwey, and Overbeek. It is universally included in text books on colloid chemistry and is still widely applied in modern studies of interparticle forces in colloids. In particular, the

Derjaguin approximation The Derjaguin approximation (or sometimes also referred to as the proximity approximation), named after the Russian scientist Boris Derjaguin, expresses the force profile acting between finite size bodies in terms of the force profile between two ...

is widely used in order to approximate the interaction between curved surfaces from a knowledge of the interaction for planar ones. Derjaguin was also briefly involved in

polywater Polywater was a hypothesized polymerized form of water that was the subject of much scientific controversy during the late 1960s. By 1969 the popular press had taken notice and sparked fears of a "polywater gap" in the US. Increased press attent ...

research during the 1960s and early 1970s. This field claimed that if

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

was heated then cooled in

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

capillaries, it took on astonishing new properties. Eventually, the scientists who were involved in polywater admitted it did not exist, claiming they were misled by poorly designed experiments (Derjaguin rejected polywater in 1973). He is also known for having hotly rejectedD. Maugis, ''Contact, Adhesion and Rupture of Elastic Solids'', Springer-Verlag, Solid-State Sciences, Berlin 2000, some of the then-new ideas of adhesion as presented by the Western blocB. V. Derjaguin, V. M. Muller and Y. P. Toporov, "Effect of contact deformations on the adhesion of particles", ''J. Colloid Interface Sci.'' 53 (1975), pp. 314-325 in the 1970s. His model came to be known as the DMT (after Derjaguin, Muller and Toporov) model, while the model presented by Western bloc scientists came to be known as the JKR (after Johnson, Kendall and Roberts)K. L. Johnson, K. Kendall and A. D. Roberts, "Surface energy and the contact of elastic solids", ''Proc. R. Soc. Lond. A 324'' (1971), pp. 301-313 model for adhesive elastic contact. This rejection proved to be instrumental in the development of the TaborD. Tabor, "The hardness of solids", ''Rev. Phys. Technol.'' 1 (1970), pp. 145-179D. Tabor, "Surface forces and surface interactions", ''J. Colloid Interface Sci.'' 58 (1977), pp. 2-13 and later MaugisD. Maugis, "Adhesion of spheres: The JKR-DMT transition using a Dugdale model", ''J. Colloid Interface Sci.'' 150 (1992), pp. 243-269 parameters that quantify which contact model (of the JKR and DMT models) represent adhesive contact better for specific materials.

Selected works

From 1980 onwards

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Reprints

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References

{{DEFAULTSORT:Derjaguin, Boris 1902 births 1994 deaths 20th-century Russian chemists 20th-century Russian physicists Scientists from Moscow Corresponding Members of the USSR Academy of Sciences Full Members of the Russian Academy of Sciences Members of the German Academy of Sciences Leopoldina Recipients of the Order of the Red Banner of Labour Recipients of the USSR State Prize Tribologists Russian chemists Russian physical chemists Russian physicists Soviet chemists Soviet physical chemists Soviet physicists Burials at Vagankovo Cemetery

Selected works

From 1980 onwards

Reprints

See also

References