title: A colloidal route to fabricate hierarchical sticky and non-sticky substrates.
abstract: We present a facile and inexpensive bottom-up colloidal route to prepare sticky superhydrophobic surfaces and non-sticky ones. Either spin coating to assemble silica microspheres into random multilayered arrays or irreversible adsorption of gold nanoparticles is used to manufacture substrates with a single length scale roughness. Hierarchical roughness with multiple length scales is achieved by decorating the silica spheres with gold nanoparticles. The surface chemistry of the silica surfaces is modified by the adsorption of fluoroalkylsilane self-assembled monolayers, while gold nanoparticles are hydrophobized by dodecanethiol. The wetting properties, both static and dynamic, of surfaces in relation to the morphology of the substrates are addressed. We demonstrate the role of hierarchy in the roughness in converting a sticky into a non-sticky superhydrophobic surface and discuss the results in terms of existing models describing wetting characteristics.
authors.affiliation: Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
authors.forename: Muhammad Akram
authors.initials: MA
authors.lastname: Raza
authors.forename: E Stefan
authors.initials: ES
authors.lastname: Kooij
authors.forename: Arend
authors.initials: A
authors.lastname: van Silfhout
authors.forename: Harold J W
authors.initials: HJ
authors.lastname: Zandvliet
authors.forename: Bene
authors.initials: B
authors.lastname: Poelsema
mesh_terms: D003102:Colloids; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008863:Microspheres; D008956:Models, Chemical; D012822:Silicon Dioxide / Q000737:chemistry*; D017155:Wettability
chemical_list: D003102:Colloids; D006046:Gold; D012822:Silicon Dioxide