Three-dimensional triple hierarchy formed by self-assembly of wax crystals on CuO nanowires for nonwettable surfaces

Jun Young Lee, Sasha Pechook, Deok Jin Jeon, Boaz Pokroy, Jong-Souk Yeo

Research output: Contribution to journalArticle

18 Citations (Scopus)


Novel hierarchical surfaces combining paraffin wax crystals and CuO nanowires are presented. We demonstrate a bioinspired hierarchical wax on nanowire (NW) structures having high water and ethylene glycol repellence. In general, vertically grown nanowire arrays can provide a superhydrophobic surface (SHS) due to extremely high surface roughness but cannot repel ethylene glycol. In this paper, C36H74 and C50H102 waxes are thermally evaporated on the surface of CuO NWs, forming highly ordered, three-dimensional (3D) hierarchical structures via self-assembly of wax crystals. These two and three level hierarchical structures provide perfect self-cleaning characteristics, with water contact angles (CAs) exceeding 170°. Furthermore, C36H74 and C50H 102 wax crystals assembled perpendicularly to the longitudinal NW axis form a re-entrant (that is, a multivalued surface topography) curvature enabling high repellence to ethylene glycol (EG) with CAs exceeding 160°. We analyze the wettability dependence on wax crystal size and structure for the optimization of nonwettable hierarchical structured surfaces.

Original languageEnglish
Pages (from-to)4927-4934
Number of pages8
JournalACS Applied Materials and Interfaces
Issue number7
Publication statusPublished - 2014 Apr 9


All Science Journal Classification (ASJC) codes

  • Materials Science(all)

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