Robust Technique Allowing the Manufacture of Superoleophobic (Omniphobic) Metallic Surfaces

Abstract

Omniphobic metallic surfaces obtained with a robust two‐stage process are reported. The surfaces demonstrate high apparent contact angles accompanied with a low contact angle hysteresis for a variety of liquids, including water, diidomethane, canola, castor, silicone oils, and crude petroleum oil. The superoleophobicity was achieved by fluorination of the nano‐rough aluminum surfaces under treatment with perfluorononanoic acid, as established by TOF‐SIMS spectrometry. The stability of the Cassie wetting regime was investigated. The critical surface tension of a liquid corresponding to the onset of wetting transitions was established experimentally.