화학공학소재연구정보센터
Langmuir, Vol.28, No.27, 10177-10182, 2012
Spontaneous Formation of Linearly Arranged Microcraters on Sol-Gel-Derived Silica-Poly(vinylpyrrolidone) Hybrid Films Induced by Benard-Marangoni Convection
Complex, sophisticated surface patterns on micrometer and nanometer scales are obtained when solvent evaporates from solutions containing nonvolatile solutes dropped on a solid substrate. Such evaporation-driven pattern formation has been utilized as a fabrication process of highly ordered patterns in thin films. Here, we suggested the spontaneous pattern formation induced by Benard-Marangoni convection triggered by solvent evaporation as a novel patterning process of sol-gel-derived organic-inorganic hybrid films. Microcraters of 1.0-1.5 mu m in height and of 100-200 mu m in width were spontaneously formed on the surface of silica-poly(vinylpyrrolidone) hybrid films prepared via temperature-controlled dip-coating process, where the surface patterns were linearly arranged parallel to the substrate withdrawal direction. Such highly ordered micropatterns were achieved by Benard-Marangoni convection activated at high temperatures and the unidirectional flow of the coating solution on the substrate during dip-coating.