Slide 2 of 12
Notes:
…quite analogous to air flotation, which most of you are no doubt familiar with. The colloid particle becomes the AFM tip interacting with the oil-water interface, gathering quantitative force data that will help define the roles of non-DLVO forces, like the hydrophobic attraction.
The true mechanism of the so-called hydrophobic force remains in dispute, but even more intriguing are the unreconciled experimental facts that rate how important it is in the aggregation of hydrophobic bodies dispersed in polar media. While the hydrophobic effect may play a dominant role in air-flotation, our direct measurements of particle-drop interactions indicate this is not the whole story.
Other interactions of particular interest to us are the hydrodynamic lubrication of deformable interfaces, the steric repulsion of adlayers, and depletion of free polymer in draining films.
The natural byproduct of these investigations is a standard technique for analyzing the fluid interface (FI) AFM data. The single greatest difficulty is the experimenter’s lack of knowledge about the separation between the sphere and deforming interface.