INTERACTION BETWEEN ADSORPTION LAYERS OF MACROMOLECULES

Abstract
Stability and rheological properties of concentrated emulsions (including those for manufacture of vitamin microcapsules) can be related to elementary coalescence acts and adhesion of emulsion drops interacting through thin layers (microscopic emulsion films) of a dispersion medium A new procedure was used for measuring the adhesion force fa between two drops of n-heptane in polymer solutions and lifetime τ of the drops in the contacts depending on the volume concentration C of the polymer, time of formation tf of adsorption layers, temperature T, capillary pressure Pc in the film, surface area S of the film, and on addition of acetone and tannin. The molecular mechanism of the interaction between adsorption layers of polymers and of the process of film destruction is discussed on the basis of the relationships obtained for interaction free energy Δ Fa, activation energy E, destruction activation volume δ and physico-chemical parameters.