Preparation and surface properties of silica-gel coating films containing branched-polyfluoroalkylsilane
| Autor: | Takeo Konakahara, Fujito Nemoto, Hiroyuki Fukube, Toshinobu Yoko, Takashi Monde |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Materials science
Silica gel Methyltrimethoxysilane engineering.material Condensed Matter Physics Silane Surface energy Electronic Optical and Magnetic Materials Contact angle chemistry.chemical_compound chemistry Chemical engineering Coating Polymer chemistry Materials Chemistry Ceramics and Composites engineering Gravimetric analysis Thermal stability |
| Zdroj: | Journal of Non-Crystalline Solids. 246:54-64 |
| ISSN: | 0022-3093 |
| DOI: | 10.1016/s0022-3093(99)00003-4 |
| Popis: | Composite coating films crack-free and with smooth surfaces have been prepared by the sol–gel technique using branched chain polyfluoroalkylsilane (triethoxy[4,4-bis(trifluoromethyl)-5,5,6,6,7,7,7-heptafluoroheptyl]silane) (D3Et) and tetraethoxysilane (TEOS) as starting materials. Surface properties of the fluorinated coating films heated at various temperatures were examined in comparison with films derived from methyltrimethoxysilane (MTM) and TEOS, based on the measurements of infra-red spectra, thermal gravimetric changes and X-ray photoelectron spectra and contact angle of water and diiodo methane. It was found that the fluorosilane-containing films had thermal stability and surface energies, γ s , as small as polytetrafluoroethylene (PTFE) up to 400°C and a large contact angle of water comparable to the films derived from MTM and TEOS. Large hydrophobicity of fluorosilane-containing films seems to be due to the dispersion component of the surface energy compared with methyltrimethoxysilane and TEOS films. We conclude from X-ray photoelectron spectra measurements that the surface energy of the fluorinated coating film originate from polyfluorocarbon molecules at the topmost film surface. |
| Databáze: | OpenAIRE |
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