Highly ordered, hexagonally patterned poly(methyl methacrylate) (PMMA) thin film is successfully fabricated using an improved phase separation method. A mixture of chloroform and methanol, which is used as a volatile solvent/nonsolvent pair, effectively controls the surface morphology and sensitively determines the ordered pattern. In particular, the methanol accumulation, which induces the formation of a gel-like protective layer and enhances the lateral capillary force, is crucial in the formation of the highly ordered hexagonal pattern even when using a nonpolar polymer such as PMMA. The convergence of cost-effective and large-scale production of highly ordered micropatterned film has wide potential for application, and it can enable new prospects for the commercialization of future high-tech devices that require specific multifunctionality.
Keywords: honeycomb film; methanol accumulation; ordered structure; phase separation; poly(methyl methacrylate).