title: Surface morphology control of polymer films by electron irradiation and its application to superhydrophobic surfaces.
abstract: A simple and controllable one-step method to fabricate superhydrophobic surfaces on poly(tetrafluoroethylene) (PTFE) films is developed on the base of electron irradiation. When the thickness of PTFE films is higher than the penetration depth of electron beams, electrical charging occurs at the surface of the films because of the imbalance between the accumulation of incident electrons and the emission of secondary electrons. Local inhomogeneity of charge distribution due to this electrical charging results in the nonuniform decomposition of PTFE molecular bonds. As electron fluence increases, surface morphology and surface roughness of the films are dramatically changed. An extremely rough surface with micrometer-sized pores is produced on the surface of PTFE films by electron irradiation at a fluence higher than 2.5 × 10(17) cm(-2).Because of high surface roughness, the irradiated PTFE films exhibit superhydrophobic property with a water contact angle (CA) greater than 150° at fluences ranging from 4 × 10(17) to 1 × 10(18) cm(-2). The surface morphology and corresponding water CA can be controlled by simply changing the electron fluence. This electron irradiation method can be applicable to the fabrication of superhydrophobic surfaces using other low-surface-energy materials including various fluoropolymers.
authors.affiliation: Radiation Research Division for Industry and Environment, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 580-185, Republic of Korea.
authors.forename: Eun Je
authors.initials: EJ
authors.lastname: Lee
authors.forename: Chan-Hee
authors.initials: CH
authors.lastname: Jung
authors.forename: In-Tae
authors.initials: IT
authors.lastname: Hwang
authors.forename: Jae-Hak
authors.initials: JH
authors.lastname: Choi
authors.forename: Sung Oh
authors.initials: SO
authors.lastname: Cho
authors.forename: Young-Chang
authors.initials: YC
authors.lastname: Nho
mesh_terms: D004583:Electrons; D057927:Hydrophobic and Hydrophilic Interactions; D011108:Polymers / Q000737:chemistry*; D011138:Polytetrafluoroethylene / Q000737:chemistry; D016062:Porosity; D013499:Surface Properties
chemical_list: D011108:Polymers; D011138:Polytetrafluoroethylene