Evaporation-driven self-organization of sol–gel dip-coating films

Abstract

In this review, we discuss the spontaneous pattern formation of sol–gel dip coating films induced by solvent evaporation, as a novel patterning technique. Linearly arranged striations and cell-like patterns were obtained upon withdrawing the substrate from the coating solution at increasing withdrawal rates. Such highly ordered micropatterns formed by the Bénard–Marangoni convection mechanism triggered by solvent evaporation. In contrast, dip-coating at rates below 1.0 cm min⁻¹ generated periodic stripe patterns arranged on the surface of the films that were perpendicular to the substrate withdrawal direction. Such a formation design was attributed to the onset of capillary flow of the coating solution at the meniscus induced by solvent evaporation.