Plasma treatment of silicone oil- infused surfaces switches impact of water droplets from bouncing to tanner-like spreading

Bouncing of water droplets on cold-plasma-treated and non-treated silicone-oil-infused microporous surfaces is reported. Cold plasma treatment of oil-infused surfaces switches the quasi-elastic bouncing to a two-stage spreading. At the first stage, spreading was governed by the square-root time dependence of the contact radius; whereas at the final stage, the kinetics of spreading conformed with the Tanner-like law. Water droplets placed on the pristine silicone-oil infused surfaces are eventually coated with the silicone oil; in contrast water droplets spread on the plasma-treated oil remained uncoated, due to the increase of the specific energy of the silicon oil induced by the plasma treatment. The semi-qualitative analysis of bouncing is introduced.