Sphere tensiometry: wall effects and correction factors

Abstract

This paper is a supplement to an earlier one on the new absolute gravimetric method of measuring surface and interfacial tension which takes into account the effect of the wall in circular containers of finite radius which causes the liquid surface to dimple instead of remaining flat as in an unbounded system as assumed earlier.Using conventional capillarity theory, the basic principles for correcting force–displacement curves, called sphere-tensiograms, are derived. Numerical correction factors calculated from the theory for systems with perfect wetting (zero contact angle) for an experimentally realistic range of parameters, and corroborative experimental data are presented.