Candle Soot as a Template for a Transparent Robust Superamphiphobic Coating

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Science  01 Dec 2011:
DOI: 10.1126/science.1207115


Coating is an essential step in adjusting the surface properties of materials. Superhydrophobic coatings with contact angles greater than 150° and roll-off angles below 10° for water have been developed, based on low energy surfaces and roughness on the nano- and micrometer scales. However, these surfaces are still wetted by organic liquids such as surfactant-based solutions, alcohols, or alkanes. Coatings that are simultaneously superhydrophobic and superoleophobic are rare. We designed an easily fabricated, transparent, and oil-rebounding superamphiphobic coating. A porous deposit of candle soot was coated with a 25-nm-thick silica shell. The black coating became transparent after calcination at 600°C. After silanization, the coating is superamphiphobic and remained so even after its top layer was damaged by sand impingement.