ABSTRACT
From examination of the dewetting process, the requirement for the wettable (by water) or hydrophilic surface could be defined that the contact angle of water should be below p/2. By the same principle, a contact angle above p could be set as the requirement for the nonwettable or hydrophobic surface. The surface whose contact angle is between p and p/2 could be viewed as the surface having amphoteric wettability or amphoteric hydrophilicity/hydrophobicity.
