Self-cleaning and anti-fouling superhydrophobic hierarchical ceramic surface synthesized from hydrothermal and fluorination methods

In this work, we develop superhydrophobic ceramic surfaces possessing flower-like hierarchical structures that can resist surface wetting against not only water but also ethylene glycol and palm oil. This can benefit a wide range of potential applications in many ceramic fields. The synergistic strategy to fabricate superhydrophobic ceramic surfaces relies on the construction of hierarchical structures through pre-roughening. Using TiO2 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-TiO2-modified ceramic surface (C8/TiO2-CRM) can still maintain a high contact angle against palm oil (above nearly 120°) within 40 min of exposure, whereas the un-textured ceramic surface is fully wetted. In addition, the C8/TiO2-CRM has excellent self-cleaning, anti-fouling and “gasphilic” properties. In this work, the robustness of the composite interface from hierarchical structures resulting from TiO2 micro-flowers is further explained.