Solution Spraying of Poly(methyl methacrylate) Blends to Fabricate Micro-textured, Superoleophobic Surfaces

Siddarth Srinivasan, Shreerang S. Chhatre, Joseph M. Mabry, Robert E. Cohen and Gareth H.

McKinley

We describe a simple technique to prepare superhydrophobic and superoleophobic micro-textured surfaces by spray coating a blend of poly(methyl methacrylate) (PMMA) and the low surface energy molecule 1H,1H,2H,2H-heptadecafluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS, γsv ≈ 10 mN/m) using an air brush with a pressurized nitrogen stream. Scanning

electron micrographs show the formation of micro-textured surfaces possessing re-entrant curvature; a critical feature for obtaining liquid repellency with low surface tension liquids. The surface morphology can be tuned systematically from a corpuscular or spherical microstructure to a beads-on-string structure and finally to bundled fibers by controlling the solution concentration and molecular weight of the sprayed polymer. The oleophobicity of the resulting structures is characterized by advancing and receding contact angle measurements with liquids of a range of surface tensions.

Keywords: non-woven; fiber; superhydrophobic; superoleophobic; spray coating; beads on string;