Surface Chemistry DOI: 10.1002/anie.201101008 Superoleophobic Coatings with Ultralow Sliding Angles Based on Silicone Nanofilaments** Junping Zhang and Stefan Seeger Inspired by the self-cleaning and water-repellent properties of the lotus leaf [1] and the leg of the water strider [2] in the natural world, artificial superhydrophobic surfaces have generated extensive attention in academia and industry. [3] It is well- known that combining appropriate surface roughness and materials with a low surface energy is a successful way to prepare superhydrophobic surfaces. [4] However, it is not so easy to create superoleophobic surfaces that resist wetting of nonpolar liquids because of their low surface tension (for example, 27.5 mN m 1 for hexadecane and 23.8 mN m 1 for decane compared to 72.8 mN m 1 for water). From experience in designing superhydrophobic surfaces, many groups have tried various techniques to create super- oleophobic surfaces. [5, 6] However, most of the reported super- oleophobic surfaces are limited to nonpolar liquids with surface tensions of more than 27 mN m 1 . Moreover, the droplets often have high contact angles (CA  1508) but adhere on the surface and cannot roll off, even when the surface is turned upside down. [6] In fact, it is very challenging to create superoleophobic surfaces on which the droplets of nonpolar liquids could roll off easily (sliding angle (SA) < 108) as the interaction between droplets and surfaces should be very weak. [7] Both a special microstructure and materials with very low surface tension are necessary. Until now, only a few studies have reported such low SA for nonpolar liquids by using inherently textured fabrics as substrates or by introduc- ing some specially designed patterns, such as overhang structures and re-entrant surface curvatures. [8] However, the fabrication of such microstructures is limited to particular substrates (such as silicon wafers and aluminum foil) or relies on complicated etching-in methods (such as lithography and anodization), which means a significant restriction of appli- cations. Herein, we present a novel simple grow-from approach for the fabrication of superoleophobic surfaces by the combination of versatile organosilanes. Coating of surfaces with organosilanes is well-known because of its fine proper- ties and simplicity. [9] The structure and properties of the coatings are determined by many factors, including the number of organosilane reactive groups, alkyl group struc- ture, and reaction conditions. [10] Thus, there are many chances to tailor properties of the coatings. In 2003, we prepared for the first time a new group of nanostructures called silicone nanofilaments by chemical vapor deposition of organosilanes on various substrates. [11, 12] The coatings exhibit excellent superhydrophobicity and chemical and environmental stabil- ity. For the fabrication of superoleophobic coatings herein, silicone nanofilaments with different microstructures were grown in toluene onto glass slides by simply regulating the water concentration during hydrolysis and condensation of trichloromethylsilane (TCMS). Subsequently, the nanofila- ments were activated using O 2 plasma and then modified with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (PFDTS; Figure 1). The superoleophobic surfaces thus obtained fea- ture a high CA and ultralow SA for various nonpolar liquids (such as mineral oil, toluene, hexadecane, decane, and cyclohexane), excellent transparency, and chemical and environmental stability. Once injected into toluene, TCMS will hydrolyze in the presence of water and self-assemble into a crosslinked polymeric network that is composed of a large amount of silicone nanofilaments on the surface of the substrate (Figure 1). The nanofilaments are 50–90 nm in diameter and several micrometers in length, which is somewhat thicker and longer compared to the nanofilaments we previously obtained by chemical vapor deposition. [11] The random growth of the Figure 1. a) Growth of silicone nanofilaments onto glass slides using TCMS and subsequent modification with PFDTS. b,c) Corresponding SEM images of the b) TCMS- and c) TCMS/PFDTS-coated glass slides. Both samples were prepared at C water = 124 ppm. [*] Dr. J. P. Zhang, Prof. S. Seeger Physikalisch-Chemisches Institut Universität Zürich Irchel Winterthurerstrasse 190, 8057 Zürich (Switzerland) Fax: (+ 41) 446356813 [**] We are grateful for the financial support of Alfred-Werner-Legat and the Universität Zürich. Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/anie.201101008. Communications 6652  2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Angew. Chem. Int. Ed. 2011, 50, 6652 –6656