Related Experiment Video
Updated: Jun 19, 2026

Accurate Determination of the Equilibrium Surface Tension Values with Area Perturbation Tests
Published on: August 30, 2019
SURFACE TENSION OF SERUM : XII. A TECHNIQUE FOR THE ACCURATE STUDY OF THE DROP IN FUNCTION OF THE TIME
1Laboratories of The Rockefeller Institute for Medical Research.
Abstract:
A technique is described for the study of the adsorption in function of the time of molecules of colloidal substances in the surface layer of water. This technique eliminates previous causes of error, in particular the individual coefficient. The curves obtained by plotting the data for serum at various dilutions give a clear picture of the phenomenon, and show that the low values of the initial surface tension of pure serum and serum at low dilutions are due to the extreme rapidity of adsorption of the molecules in the surface layer, owing to their high concentration. Evidence is given that colloidal substances in solution substantially lower the surface tension of the solvent, even when they are in too small a number to form an homogeneous monolayer.
Related Concept Videos
Surface Tension of Fluid
Surface tension varies with...
Surface Tension
Surface Tension and Surface Energy
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Surface Tension, Capillary Action, and Viscosity
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
Excess Pressure Inside a Drop and a Bubble

