Self-Cleaning and Anti-Fouling Omniphobic Ceramic Surface Synthesized from Hydrothermal and Fluorination Methods

In this work, we develop omniphobic ceramic surfaces possessing flower-like re-entrant structures that can resist surface wetting against not only water but also low surface tension liquids. This can benefit a wide range of potential applications in many ceramic fields. The synergistic strategy to fabricate omniphobic ceramic surfaces relies on the construction of re-entrant structures through pre-roughening. Using TiO 2 microflowers obtained via a hydrothermal approach and post-fluorinating via surface grafting with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (C8) resulted in better metastable Cassie-Baxter state as water droplet roll-off the surface compared to non-textured ceramic surfaces where the water droplet pinned. The C8-TiO 2 -modified ceramic surface (C8/TiO 2 -CRM) can still maintain a high contact angle against palm oil (above nearly 120 o ) within 40 minutes of exposure, whereas the un-textured ceramic surface is fully wetted. In addition, the C8/TiO 2 -CRM has excellent self-cleaning, anti-fouling and “gasphilic” properties. In this work, the robustness of the composite interface from secondary re-entrant structures resulting from TiO 2 micro-flowers is further explained.