title: Effect of pattern topology on the self-cleaning properties of textured surfaces.
abstract: The water contact angle and self-cleaning property of microfabricated surface textures possessing different topologies are compared. In one kind of surface textures, the protruded regions form a connected square network. In the other kind of surface textures, the protruded regions form a regular array of square posts. We find that the water apparent contact angle of the connected textures agrees with the Cassie equation [Discuss. Faraday Soc. 3, 11 (1948)], but that of the disconnected textures is much larger. Nevertheless, the disconnected textures exhibit inferior self-cleaning property, contrary to conventional conception. We discuss the possible reasons for these observations.
authors.affiliation: Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Xueyun
authors.initials: X
authors.lastname: Zhang
authors.forename: B
authors.initials: B
authors.lastname: Kong
authors.forename: O K C
authors.initials: OK
authors.lastname: Tsui
authors.forename: X
authors.initials: X
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Mi
authors.forename: C M
authors.initials: CM
authors.lastname: Chan
authors.forename: B
authors.initials: B
authors.lastname: Xu