Chris Bower produces two hand-held Nokia maze tiles to demonstrate the difference. First he drops water on a surface that has no coating at all: “The water spreads, like this, and coats the surface,” he says.
Trying the maze with the Superhydrophobic coating makes a dramatic difference: the water drops and almost bounces up again, beading tightly together – and then almost skids over the surface.
Bower explains: “A hydrophobic coating – like Teflon – has a low surface energy and a high contact angle of 120 deg, which makes water form discrete droplets on the surface.”
He goes on to explain that Superhydrophobic coatings have a contact angle that can approach 180 degrees – and the liquid forms discrete drops that literally bounce off the surface:
“The difference is the nano-structured coating, trapping air at the interface, that makes sure the liquid never actually touches the surface.”
Check out the full article at Conversations for more about this amazing technology, with pictures and video.
Watch a video of Nokia's Principal Scientist at the Nokia Research Center in Cambridge uses a Nokia Lumia 710 to demonstrate the Nokia nanotechnology behind a Superhydrophobic stain-resistant phone that repels water like a lily pad: www.youtube.com/watch