| Abstract
| - Thin layers of organosilanes on oxidic surfaces are of great interest for various applications including thecontrol of surface properties and immobilization of catalysts and biomolecules and in nanotechnology. In thepresent work, the reaction of thin layers on silicon oxide consisting of [2-[4-(chlorosulfonyl)phenyl]ethyl]trichlorosilane (CSTS) with ammonia is studied by means of contact angle (CA) measurements, ζ-potentialmeasurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FT-IR). CA measurements are used for a fast monitoring of film quality and as a first probe for the reaction ofthe CSTS sample with ammonia. The results from XPS measurements show that the chlorine peak of theCSTS molecule disappears completely after the reaction with ammonia and instead a well-resolved nitrogenpeak appears. FT-IR spectroscopy in conjunction with theoretical calculations is used to gain a more in-depthunderstanding of the chemical reaction. The shift of the asymmetric SO vibrational mode during the surfacereaction is in line with the theoretical predictions and serves as a proof for the surface reaction to happen. ByFT-IR, an additional side reaction of sulfonic acid groups, which are present in the commercial CSTS, to theammonium sulfonate salt is observed.
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