Superhydrophobic surfaces produced by applying a self-assembled monolayer to silicon micro/nano-textured surfaces

Abstract

A novel way of producing superhydrophobic surfaces by applying a self-assembled monolayer (SAM) to silicon micro/nano-textured surfaces is presented in this paper. The micro/nano-textured surfaces on silicon substrates were generated by the aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) technique. Octadecyltrichlorosilane (OTS) SAMs were then applied to the textured surfaces by dip coating. The topography and wetting properties of the resulting surfaces were characterized using scanning electron microscopy (SEM) and a video-based contact angle measurement system. The results show that by introducing OTS SAMs on the silicon micro/nano-textured surfaces, superhydrophobic surfaces with water contact angles (WCAs) of 155° were obtained, as compared to the WCAs of OTS-modifi ed smooth silicon surfaces of about 112°. Surface topography was found to directly infl uence the WCA as predicted by the Cassie-Baxter model.

Nanodrop on a nanorough hydrophilic solid surface: Contact angle dependence on the size, arrangement, and composition of the pillars

“…The progress of modern nanotechnologies allows one to fabricate surfaces with prescribed structure, for instance, decorated with asperities of various shapes, sizes, and compositions [1][2][3][4][5][6]. Such modifications of the surface lead to considerable changes of its wetting properties.…”

Wetting properties of silicon films from alkyl-passivated particles produced by mechanochemical synthesis

“…To estimate the fraction f 1, a calculation based on ImageJ developed by the National Institute of Health was introduced by Y. Wang [20]. The same calculation was carried out for films obtained from milling times of 4, 8 and 12 h. For these times the values of f 1 were 12.7%, 22.5% and 15.3%, respectively.…”

“…These structural features are applied to artificial surfaces mainly via two approaches: establishing a combination of micro-and nanostructures on hydrophobic substrates, or chemically altering a micro-and nanoscale structured surface with materials of low surface energy [10]. Various fabrication methods have been proposed based on these approaches, including lithographic patterning [1,[11][12][13], vapor deposition [14,15], utilization of templates [16], chemical deposition [17][18][19] self-assembled monolayers [20], layer-by-layer (LBL) [21,22], sol-gel methods with phase separation [23,24], plasma etching [25,26], and bottom-up approaches [27]. Previously we reported that high energy ball milling (HEBM) is an alternative route to the production of functionalized silicon nanoparticles [28].…”

Fluorine‐Free Superhydrophobic Microstructured Films Grown by PECVD

“…Some examples are phase separation, [3] sol-gel silica-based films, [4] isolated nanodots formed by induced crystallization, [5] deposition of inorganic nanoparticles, [6,7] controlled thermal treatment to obtain nanoparticles from an adsorbed precursor, [8] chemical grafting deposition of a monolayer of polystyrene spheres as templates, [9,10] electrochemical deposition, [11] controlled growth of carbon nanotubes normal to the surface, [12] and graphite oxide from a grapheme surface. [13] Surface energy can then be reduced by a self-assembled monolayer (SAM) of chlorosilanes, [5] thiols, [14] fluorosilanes, [4] or by plasma fluorination. [15][16][17] Indeed, plasma treatments are often used to increase the WCA by surface grafting of elemental fluorine or by creating a new fluorinecontaining top layer.…”