Wetting transitions

When a liquid droplet is put onto a surface, two situations distinguishable by the contact angle may result. If the contact angle is zero, the droplet spreads across the surface, a situation referred to as complete wetting. Second, if the contact angle is between 0degrees and 180degrees, the droplet does not spread; a situation called partial wetting. A wetting transition is a surface phase transition from partial to complete wetting. We present experiments that show three different ways in which the wetting transition can come about. (C) 2002 Elsevier Science B.V. All rights reserved.