Candle Soot as a Template for a Transparent Robust Superamphiphobic Coating

Coating is an essential step in adjusting the surface properties of materials. Superhydrophobic coatings with contact angles greater than 150 degrees and roll-off angles below 10 degrees 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-nanometer-thick silica shell. The black coating became transparent after calcination at 600 degrees C. After silanization, the coating was superamphiphobic and remained so even after its top layer was damaged by sand impingement.