Direct measurements of long-range surface forces in gas and liquid media

• Published in: Advances in colloid and interface science Vol. 16; no. 1; pp. 63 - 78
• Main Authors: Rabinovich, Ya.I., Derjaguin, B.V., Churaev, N.V.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1982
• ISSN: 0001-8686; 1873-3727
• DOI: 10.1016/0001-8686(82)85007-0

A modified set-up was applied to carry out direct measurements of the forces of molecular attraction of gold spheres and crossed quartz filaments in air within the region of distances from 10 to 100 nm. Some quantitative deviations from Lifshitz's theory for gold may be attributed to an insufficient reliability of the spectral data used in the calculations. The DLVO theory adequately describes the interaction of glass threads in KCl (10 −3 ÷ 10 −5 N) solutions within the region of 5 to 100 nm. At a distance smaller than 5 nm, the deviations from DLVO theory are attributable to the influence of structural forces. When the contact between crossed hydrophobized quartz threads in water is broken, the attraction forces (which exceed the molecular forces by several orders of magnitude) at a distance of up to 300 nm are detected.