Effect of contact deformations on the adhesion of particles

doi:10.1016/0021-9797(75)90018-1

Journal of Colloid and Interface Science

Volume 53, Issue 2, November 1975, Pages 314-326

https://doi.org/10.1016/0021-9797(75)90018-1 Get rights and content

Abstract

A strict theory of reciprocal influence of the contact deformation and molecular attraction of a ball and a plane has been developed. It has been shown that despite the van der Waals' forces being capable of increasing the elastic contact area between the ball and the plane, the force that is required to overcome the molecular forces arising when the contact is broken does not increase thereby. In fact, it remains equal to the attraction force value that is determined when considering the point contact of a nondeformed ball with a plane.

In the absence of the electrostatic component, the adhesion force is equivalent to the first power of the ball radius and to the amount of work per unit area as required for effecting the equilibrium tearing-off of a flat surface of the same nature.

References (18)

B.V Derjaguin
Koll. Z.
(1934)
L.D Landau et al.
Theory of Elasticity
(1970)
R.S Bradley
Philos. Mag.
(1932)
R.S Bradley
Trans. Faraday Soc.
(1936)
H.C Hamaker
Physica
(1937)
K.L Johnson et al.
B Dahneke
J. Colloid Interface Sci.
(1972)
H Hertz
Gesammelte Werke
(1895)
I.S Gradstein et al.
Tables of Integrals, Sums, Series, and Products
(1971)
H.B Dwight
Tables of Integrals and Other Mathematical Formulas
(1964)
L.S Leibenson
Curriculum of the Theory of Elasticity
(1947)

There are more references available in the full text version of this article.

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Effect of contact deformations on the adhesion of particles

Abstract

Koll. Z.

Philos. Mag.

Trans. Faraday Soc.

Physica

J. Colloid Interface Sci.

Gesammelte Werke

Tables of Integrals, Sums, Series, and Products

Tables of Integrals and Other Mathematical Formulas

Curriculum of the Theory of Elasticity