On the Impact of Drying on Surface Tension Gradient Induced Marangoni Convection in Thin Polymer Solution Films

Thin functional polymer films are widely used in classic applications and novel (organic) electronic devices. Typically, such films are produced by polymer-solution coating and subsequent drying. Thin liquid films, however, may be subject to surface tension gradient driven convective instabilities, which bear the potential of causing free surface deformations that may persist in the solidified dry films. While stationary convective instabilities are well understood in single-component non-volatile liquid films, the intrinsic non-stationarity of polymer solution film drying, due to transient film shrinkage, concentration change, and viscosity increase, are subject of ongoing scientific research. The aim of this work is the investigation of the impact of drying conditions on the occurrence and lifetime of convective instabilities in thin drying polymer-solution films, by means of quantitative experimental investigations.