Viscosity effects on hydrodynamic drainage force measurements involving deformable bodies

Abstract

Dynamic force measurements have been made between an oil drop and a silica particle in surfactant and sucrose solutions with viscosities that range up to 50 times that of water. These conditions provide variations in the shear rate and the relative time scales of droplet deformation and hydrodynamic drainage in asoft matter system. The results obtained indicate that soft deformable boundarieshave a natural response that limits the maximum shear rate that can be sustained in thin films compared to shear rates that can be attained in films bounded by rigid boundaries. In addition, to extend boundary slip studies on rigid surfaces,weuse a smooth deformable droplet surface to probe the dependenc..