Title: Self-assembled monolayers on ta-C surfaces: Effect of sp3/sp2 ratio on adsorption rate and friction
Abstract:Self-assembled monolayers of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS), CF3(CF2)7(CH2)2SiCl3 were deposited on tetrahedral amorphous carbon (ta-C) surfaces by immersion process. The ta-C films ...Self-assembled monolayers of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS), CF3(CF2)7(CH2)2SiCl3 were deposited on tetrahedral amorphous carbon (ta-C) surfaces by immersion process. The ta-C films were deposited on silicon substrates by using a filtered cathodic arc system and the sp3/sp2 ratios of the ta-C films were controlled by changing the sample bias voltage. In results of the x-ray photoelectron spectroscopy measurements, it was found that the adsorption rate of silane molecules on sample A (whose sp3 content is about 85%) was higher than that of on sample B (whose sp3 content is about 65%). This trend was qualitatively the same as that found for water contact angle measurement. The friction forces of FDTS/sample A and FDTS/sample B measured by lateral force microscope show FDTS/sample A has lower friction value than that of FDTS/sample B. We conclude the following: the density of dangling bonds, which are effective adsorption sites for silane molecules, increases with sp3 content. Consequently, the adsorption rate of silane molecules increases with increasing sp3 content. The friction force decreases with increasing sp3 content of the ta-C film since more of a close-packed self-assembled monolayer can be formed.Read More
Publication Year: 2003
Publication Date: 2003-05-15
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 5
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