title: Communications: Wall free capillarity and pendant drop removal.
abstract: When a sessile drop encounters a pendant drop through a hole, it is generally anticipated that they will coalesce and flow downward due to gravity. However, like "wall-free" capillarity, we show that the pendant drop may be sucked up by a sliding drop instantaneously if the radius of the curvature of the former is smaller than that of the later. This phenomenon can be explained by Laplace-Young equation and convective Ostwald ripening. Our results indicate that superhydrophilic perforated surface can be used as an effective way for the removal of small droplets adhering to the inner walls of microchannel systems.
authors.affiliation: Department of Chemical and Materials Engineering, National Central University, Jhongli, Taiwan 320, Republic of China.
authors.forename: Siang-Jie
authors.initials: SJ
authors.lastname: Hong
authors.forename: Feng-Ming
authors.initials: FM
authors.lastname: Chang
authors.forename: Seong Heng
authors.initials: SH
authors.lastname: Chan
authors.forename: Yu-Jane
authors.initials: YJ
authors.lastname: Sheng
authors.forename: Heng-Kwong
authors.initials: HK
authors.lastname: Tsao