Atmospheric Pressure Plasma Deposition of Hydrophilic/Phobic Patterns and Thin Film Laminates on Any Surface

Patterned and layered hydrophilic/phobic coatings were deposited on multiple surfaces using nonfluorinated precursors (AA, acrylic acid; PMA, propargyl methacrylate) with an atmospheric pressure dielectric barrier discharge operating in open air. Water contact angles of the resulting films could be tuned from <5° (superhydrophilic) to >135° (very hydrophobic) by adjusting the AA/PMA feed ratio and/or via postdeposition exposure of films to an Ar/O₂ plasma treatment. Coatings could be applied to any surface and were seen to be water stable, due in large part to cross-linking induced from the reactivity of the PMA pendant groups. Hybrid hydrophilic/phobic patterns at submillimeter length scales, and philic/phobic/philic laminates were produced using a shadow mask and sequential deposition, respectively. Chemical heterogeneity of films was assessed using XPS, SIMS, and micro-IR imaging and suggest that localization of COOH and OH groups are primarily responsible for hydrophilicity. Overall, this work demonstrates that atmospheric pressure plasma polymerization is a simple and scalable method for robust and tunable control of wettability of surfaces of all kinds.