Grafting characterization of thin organosilane films on silica substrate
- Laboratoire d`Etudes des Materiaux Plastiques et des Biomateriaux-URA CNRS n507, Universite Claude Bernard LYON I, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex (France)
- Laboratoire des Materiaux Macromoleculaires-URA CNRS n507, I.N.S.A. LYON, 20 Avenue Albert Einstein, 69621 Villeurbanne Cedex (France)
Silanes are widely used as coupling agents favouring the adhesion of organic polymers to an inorganic surface. As a model system for the composite interface, we have used grafted n-alkylsilane on various silica substrates. Contact angles by the sessile drop method were measured as a function of varying alkyl chain lengths, chemical structure and deposition conditions. We found that the silanization of surfaces involved the reaction of monofunctional alkyl-silanes with surface hydroxyl groups, through which organic moieties were covalently bonded resulting in a single monolayer. Modified surfaces showed a high contact angle with water and a low non dispersive component of surface energy as olefinic surfaces. The wetting of these monolayers was found to be slightly dependent on the chain length. Silane films adsorbed from solution showed wetting properties reflected the insertion of solvent between the grafted molecules. Surface coverage determined by {sup 29}Si NMR as a function of chain length indicated that the bonded long alkyl chains had a flat conformation whereas the short chains could be {l_angle}{l_angle}bristly{r_angle}{r_angle} or brush-like. By varying the chemical structure and the number of functional groups at the silane end, it was shown that aminosilane appeared to be the most reactive. In addition, the films made from trifunctional silanes having long alkyl chains exhibited disorder and poor orientation. {copyright} {ital 1996 American Institute of Physics.}
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 286466
- Report Number(s):
- CONF-950119-; ISSN 0094-243X; TRN: 9615M0024
- Journal Information:
- AIP Conference Proceedings, Vol. 354, Issue 1; Conference: 53. international meeting of physical chemistry: organic coatings, Paris (France), 2-6 Jan 1995; Other Information: PBD: Jan 1996
- Country of Publication:
- United States
- Language:
- English
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