Polymethylhydrosiloxane-based organicinorganic hybrids for amphiphobic coatings

Amphiphobic organicinorganic hybrid coating materials have been prepared by solgel technique in two steps. In the first step, fluorinated polymethylhydrosiloxane precursor was synthesized by hydrosilylation reaction with polymethylhydrosiloxane and 2,2,3,4,4,4 hexafluorobutyl methacrylate using Pt catalyst. In the second step, fluorinated polymethylsiloxane/silica hybrid (FSH) dispersion was prepared by the reaction of the precursor and tetraethyl orthosilicate with equivalent amounts of water and different quantities of ethanol at 7080 degrees C for 24h. The hybrid dispersions were spin-coated on a glass substrate and thermally cured at 150 degrees C. The hybrids were analysed by high-resolution scanning electron microscopy with energy-dispersive X-ray spectroscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The dynamic contact angle was measured on the coated substrate by drop-shape analysis system. The prepared hybrid thin films exhibited both hydrophilic and hydrophobic properties with different scratch resistance on a glass substrate depending on the FSH compositions.