Surface morphology and wettability control of polymer Substrates: A comparison of water-miscible and water-immiscible mixture solvents

Abstract

In this work, control of the surface morphology and the wettability of polymer substrates is demonstrated using a simple one-step process. The approach is based on combining the nonsolvent-induced phase separation and a scalable dip-coating technique. Two types of solvent/nonsolvent systems, i.e. water-immiscible and water-miscible mixtures, are used to not only induce an outermost ternary solution but also produce and control the porous structure on the substrate surface through the phase separation and self-assembly of the nonsolvent-rich templating droplets. The effects of the solvent systems and their compositions on the surface features, cross-sectional morphology, and wettability are systematically investigated and compared. Furthermore, a potential mechanism for the formation of a ternary solution resulting in the micropore structure on the poly(methyl methacrylate) (PMMA) substrate surface is proposed.