Superficial dopants allow growth of silicone nanofilaments on hydroxyl-free substrates

We report new types of silicone nanostructures by a gas-phase reaction of trichloromethylsilane: 1-D silicone nanofilaments with a raveled end and silicone nanoteeth. Filaments with a raveled end are obtained on poly(vinyl chloride), which is superficially doped with the detergent Span 20. Silicone nanoteeth grow on sodium chloride using dibutyl phthalate as superficial dopant. Without dopants, no structures are observed. The dopants are identified by mass spectroscopy and the silicone nanostructures are analyzed by infrared spectroscopy and energy-dispersive analysis of X-rays. The growth of silicone nanostructures on a hydrophobic substrate (poly(vinyl chloride)/Span 20) and a substrate free of hydroxyl groups (sodium chloride/dibutyl phthalate) questions the currently discussed mechanisms for the growth of 1-D silicone nanofilaments, which is discussed. We suggest superficial doping as an alternative pretreatment method to oxidizing activation and prove this principle by the successful coating of copper, which is superficially doped with Span 20

A robust superhydrophobic TiO<inf>2</inf>NPs coated cellulose sponge for highly efficient oil-water separation

© 2017 The Author(s). Oil-water separation has recently become a worldwide concern because of the increasing oil spill accidents and industrial oily wastewater generation. Herein, a facile method with the combined superhydrophobic coating and adhesive was used to fabricate superhydrophobic TiO 2 NPs coated cellulose sponge. The developed materials exhibited excellent superhydrophobicity (WCA = 171°) and superoleophilicity (OCA = 0°), which can separate a variety of oil-water mixtures, including chloroform, toluene, kerosene and other contaminations. A high separation efficiency up to 98.5% for chloroform-water mixture was achieved when used for gravity-driven oil/water separation test. More importantly, the as-prepared samples exhibited excellent chemical stability and mechanical abrasion resistance even towards various corrosive oil/water mixtures (such as strong acid, alkali solution and salt-water environment) or a strong abrasion by aluminium oxide sandpaper of 600 mesh. In addition, the separation efficiency remained above 93% even after 40 scratch cycles, and the materials could be reused with a stable hydrophobicity, indicating a strong potential for industrial application