Article
Adsorption of Hexane and Benzene on Fluorinated Silicas: The Effect of the Perfluoralkyl Chain Length
Protection of Metals & Physical Chemistry of Surfaces
(2009)
Abstract
By means of the gas chromatography and a static adsorption method, the extent of fluorination of the carrier surface, determined by the length of the grafted radical chain, affects the adsorption properties of silicas with perfluorohexyl, perfluoropropyl, and trifluoromethyl coatings. The analysis of data on the original carrier and chemically hydrophobized silicas, including a sample with grafted octyl groups used as the reference, shows that modification leads to the decrease in both the adsorption (a at 298 K and the Henry constants (K H ) in a wide temperature range for hexane and benzene. However, in contrast to silicas with perfluoropropyl or perfluorohexyl coatings, the a and K H values on trifluorometylsilica became equal (n-alkanes) or even somewhat lower (aromatic hydrocarbons) than those observed on the non-polar octylsilica surface. Irrespective of the degree of fluorination of the silica surface, the substitution and screening of silanol groups in silica lead to weakening the polarity of polyfluoroalkylsilicas as compared with the original carrier.
Keywords
- Silica gel,
- Paraffins,
- Contact angles
Disciplines
Publication Date
March, 2009
DOI
10.1134/S207020510902004X
Citation Information
Alexander Y. Fadeev, Tat'yana M. Roshchina, Nataliya K. Shoniya, Anna B. Nikolskaia, et al.. "Adsorption of Hexane and Benzene on Fluorinated Silicas: The Effect of the Perfluoralkyl Chain Length" Protection of Metals & Physical Chemistry of Surfaces Vol. 45 Iss. 2 (2009) p. 152 - 157 Available at: http://works.bepress.com/alexander_fadeev/16/