Materials engineers have created a new type of coating that attracts water but beads up oils - traits that are usually mutually exclusive - promising potential applications such as "self-cleaning" eyeglasses and antifogging car windshields and ski goggles.
The material prevents fogging by not allowing water to form beads on surfaces, said Jeffrey Youngblood, an assistant professor of materials engineering at Purdue University.
The coating consists of a single-molecule-thick layer of a material called polyethylene glycol, and each molecule is tipped with a Teflon-like "functional group" made with fluorine. Water molecules pass through the Teflonlike layer, which acts as a barrier to the larger oil molecules. Then the water is attracted to the polyethylene glycol immediately adjacent to the glass surface.
"So, it repels the oil but not the water," said Youngblood, who is working with materials engineering doctoral student John A. Howarter. "This is important because oil normally sticks to surfaces that attract water, a property we call hydrophilic. However, we now have one that's hydrophilic but that oil doesn't like ..."
For more, see Purdue University:
http://news.uns.purdue.edu/x/2007a/0...Selfclean.html
LiveScience adds that it is considered likely that the new coating will be as effective on plastic optical materials as on glass.
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Originally Posted by crystaloptical
Coatings.
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