title: Loss of superhydrophobicity of hydrophobic micro/nano structures during condensation.
abstract: Condensed liquid behavior on hydrophobic micro/nano-structured surfaces is a subject with multiple practical applications, but remains poorly understood. In particular, the loss of superhydrophobicity of hydrophobic micro/nanostructures during condensation, even when the same surface shows water-repellant characteristics when exposed to air, requires intensive investigation to improve and apply our understanding of the fundamental physics of condensation. Here, we postulate the criterion required for condensation to form from inside the surface structures by examining the grand potentials of a condensation system, including the properties of the condensed liquid and the conditions required for condensation. The results imply that the same hydrophobic micro/nano-structured surface could exhibit different liquid droplet behavior depending on the conditions. Our findings are supported by the observed phenomena: the initiation of a condensed droplet from inside a hydrophobic cavity, the apparent wetted state changes, and the presence of sticky condensed droplets on the hydrophobic micro/nano-structured surface.
authors.affiliation: Division of Advanced Nuclear Engineering, POSTECH, Pohang, Gyungbuk, Republic of Korea.
authors.forename: HangJin
authors.initials: H
authors.lastname: Jo
authors.affiliation: Department of Mechanical Engineering, POSTECH, Pohang, Gyungbuk, Republic of Korea.
authors.forename: Kyung Won
authors.initials: KW
authors.lastname: Hwang
authors.affiliation: Division of Advanced Nuclear Engineering, POSTECH, Pohang, Gyungbuk, Republic of Korea.
authors.forename: DongHyun
authors.initials: D
authors.lastname: Kim
authors.affiliation: Division of Advanced Nuclear Engineering, POSTECH, Pohang, Gyungbuk, Republic of Korea.
authors.forename: Moriyama
authors.initials: M
authors.lastname: Kiyofumi
authors.affiliation: Division of Advanced Nuclear Engineering, POSTECH, Pohang, Gyungbuk, Republic of Korea.
authors.forename: Hyun Sun
authors.initials: HS
authors.lastname: Park
authors.affiliation: Division of Advanced Nuclear Engineering, POSTECH, Pohang, Gyungbuk, Republic of Korea.
authors.forename: Moo Hwan
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Division of Mechanical System Engineering, Incheon National University, Incheon, Republic of Korea.
authors.forename: Ho Seon
authors.initials: HS
authors.lastname: Ahn