Atomic Force Spectroscopy of Interactions between Oil Droplets in Emulsions

摘要

Atomic force microscopy (AFM) has been used to probe the effect that both adsorbing and non-adsorbing polymers have on the force interactions between oil droplets suspended in aqueous solution. At low polymer concentrations depletion effects were found to predominate in both cases. At higher polymer concentrations steric effects took over which could cause both repulsive and attractive interactions between the droplets. We show that such apparently paradoxical behaviour is rooted in the deformable nature of the oil droplets, illustrating the advantages of studying soft matter systems using AFM which allows the use of realistic samples.