What is the difference between a hydrophobic and superhydrophobic coating?


Well it seems like we are fighting a losing battle…..

“Superhydrophobic” has become the common nomenclature to describe ANY surface which easily repels liquids. Sometimes it is used correctly. Most times, however, it is incorrect. A superhydrophobic coating is a coating that has a water contact angle of greater than 150 degrees and a sliding angle of less than 10 degrees.

Most of the coatings that we have found to functionalize surfaces most effectively are not superhydrophobic –

they are hydrophobic. There are several well-known superhydrophobic products out there. The YouTube videos are compelling and jaw-dropping. How does all that mud just fall right off the clothing without staining it!? It appears to be a miracle of engineering. The problem is this: superhydrophobic coatings are NOT durable. That shirt and pants can repel mud like that until it is laundered a couple times (or maybe even just once). At that point, the coating is destabilized and the performance is lost. Recoating is prohibitively expensive, so what have we really gained? The fact is, superhydrophobic coating technology just isn’t “there” yet. The technology hasn’t advanced enough to provide durable performance for any considerable amount of time.

Having said that, yes, we can absolutely provide you a superhydrophobic coating similar to the ones that have received so much attention on the videos. The better question, though, is why do you need it? A hydrophobic coating (90 degree and greater contact angle) is sufficient for 99% of the projects we have worked on. Customers often come to us asking for a superhydrophobic coating and end up with a wonderful hydrophobic coating when we explain the difference in durability. We have been able to create stable, covalently-bonded hydrophobic coatings that last. It may not sound as cool, but hydrophobic coatings will normally be just the thing your application needs.

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