Slide 3 of 12
Notes:
Our first objective, then, is to establish the methodology for accurately accounting for drop deformation.
The interaction force is measured directly as the deflection of a Hookian spring, delta z-c of the cantilever. The other information we have is the scanner displacement, delta z, which is the sum of the drop and cantilever deflections and the separation between interfaces, S
Since the drop-profile evolution with applied force is mathematically describable, the separation can be computed from what is known.
With the DLVO and hydrodynamic forces being well understood and properly accounted for, the AFM procedure is first employed to observe and quantify hydrophobic effects between oil and polystyrene in electrolyte solutions.
Also, extremely sensitive measurements of interfacial tension are accomplished at different concentrations of ionic surfactant.
And the work is currently ongoing with experiments on steric effects of adsorbed cationic polyelectrolytes.