Superhydrophobic Paper by Facile and Fast Atmospheric Pressure Plasma Etching

Superhydrophobic and to some extent oleophobic paper surfaces are prepared using atmospheric pressure plasma etching. A novel dielectric barrier discharge operating in helium-oxygen mixture is used to rapidly etch organic material from paper surface and create hierarchical topography and subsequently a thin fluorocarbon film is deposited to modify the surface energy. The enhancement of surface topography is achieved via the selective removal of organic matter over inorganic calcium carbonate (calcite) fillers that co-exist in paper. The process led to the fabrication of roll-off superhydrophobic paper with water contact angles >150 degrees and hysteresis <10 degrees for all samples treated over 2min with no deterioration of paper quality. Further treatment over 8min resulted also in diiodomethane repellent surfaces.