title: Ultra-hydrophobic sticky polymer surfaces formed by water-induced surface deformation.
abstract: Surface properties of poly(oxyethylene)s with alkyl thioether side chains (CH3-nTE; n=carbon atoms in the side chain) were investigated. CH3-nTEs having shorter side chains (n=6, 8, 10) did not have ordered structures, while those with longer chains (n=12, 14) showed well-ordered, lamellar structures with side chain crystalline domains. Accordingly, CH3-12TE and CH3-14TE film surfaces were much more enriched with hydrophobic alkyl side chains than CH3-8TE and CH3-10TE surfaces. However, CH3-12TE and CH3-14TE films had smaller water contact angles (≈114°) than CH3-8TE and CH3-10TE films (>130°). This unexpected behavior is ascribed to the formation of very rough CH3-8TE and CH3-10TE film surfaces (Rrms>100nm) on contact with water. The CH3-10TE/poly(methyl methacrylate) (PMMA) surfaces also showed high water contact angles (>125°), even with low CH3-10TE content (30wt%), because the CH3-10TE moiety roughened the surfaces. Furthermore, ultra-hydrophobic sticky behavior was observed for CH3-nTEs (n=8, 10) and CH3-10TE/PMMA surfaces.
authors.affiliation: Interface Material and Chemical Engineering Research Center & Advanced Functional Polymer Research Center, Korea Research Institute of Chemical Technology, Daejon 305-343, Republic of Korea.
authors.forename: Eun-Ho
authors.initials: EH
authors.lastname: Sohn
authors.affiliation: Interface Material and Chemical Engineering Research Center & Advanced Functional Polymer Research Center, Korea Research Institute of Chemical Technology, Daejon 305-343, Republic of Korea.
authors.forename: Byoung Gak
authors.initials: BG
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shilim-9-Dong, Gwanak-Gu, Seoul 151-744, Republic of Korea.
authors.forename: Hyunkee
authors.initials: H
authors.lastname: Hong
authors.affiliation: Department of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shilim-9-Dong, Gwanak-Gu, Seoul 151-744, Republic of Korea.
authors.forename: Da-Jung
authors.initials: DJ
authors.lastname: Sohn
authors.affiliation: Department of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shilim-9-Dong, Gwanak-Gu, Seoul 151-744, Republic of Korea. Electronic address: jongchan@snu.ac.kr.
authors.forename: Jong-Chan
authors.initials: JC
authors.lastname: Lee
keywords: Poly(methyl methacrylte); Poly(oxyethylene)s with alkyl thioether side chains; Polymer blend; Ultra-hydrophobic sticky polymer surface; Water-induced surface deformation