Spreading Kinetics Of Shear-Thinning Fluids In Wetting And Dewetting Modes

The spreading dynamics of non-Newtonian fluids, in wetting and dewetting modes, plays a key role in numerous applications, in particular coating, adhesive bonding, and printing. The very common case of the shear-thinning behaviour has been considered in this study. The wetting dynamics has been studied by depositing sessile drops on glass slides. The dewetting kinetics has been evaluated by measuring the rate of growth of dry zones nucleated in an unstable liquid film formed on Teflon-coated glass slides. The spreading kinetics of a liquid on a rigid substrate is governed by viscous dissipation in the liquid, the capillary driving force being compensated for by the breaking force resulting from viscous shearing in the liquid.