Super hydrophobic coatings create super hydrophobic surfaces
Super-hydrophobic coatings can be made from many different materials. The following are known possible bases for the coating:
- Manganese oxide polystyrene (MnO2/PS) nano-composite
- Zinc oxide polystyrene (ZnO/PS) nano-composite
- Precipitated calcium carbonate
- Carbon nano-tube structures
- Silica nano-coating
Super-hydrophobic coatings are used to create super hydrophobic surfaces. When water or a water based substance comes into contact with these coated surfaces, the water or substance will “run off” of the surface because of the hydrophobic characteristics of the coating. Neverwet is a superhydrophobic coating made from a proprietary silicon based material that can be used to coat everything from shoes to personal electronics to aircraft.
The silica-based coatings are perhaps the most cost effective to use. They are gel-based and can be easily applied either by dipping the object into the gel or via aerosol spray. In contrast, the oxide polystyrene composites are more durable than the gel-based coatings, however the process of applying the coating is much more involved and costly. Carbon nano-tubes are also expensive and difficult to produce at this point in time. Thus, the silica-based gels remain the most economically viable option at present.
The coating creates surface contact angles of 160-175 degrees; greater than the 150 degrees necessary to deem a substance superhydrophobic. Liquids, oil, bacteria and even ice slide right off the coated surface in almost a surreal fashion. In a demonstration, the makers of Never-Wet submerged a fully functioning smartphone in water for a half hour only to come out completely dry. In another demonstration, an item submerged for over a year in seawater was retrieved completely dry and corrosion free.
Supe-hydrophobic coatings are used to create materials that are anti-wetting, anti-icing, anti-corrosion, anti-bacterial and self-cleaning. Coatings like these have the potential to increase economic spending, decrease pollutants and bacterial growth, as well as increase longevity and durability of machines that are susceptible to corrosion and water damage.