Intercalation of Polyfluorinated Surfactants into Clay Minerals and the Characterization of the Hybrid Compounds

• DOI: 10.1021/la011297x
• Publication Date: 2002-07-26T04:45:58Z
• Authors: Tatsuto Yui; Hirohisa Yoshida; Hiroshi Tachibana; Donald A. Tryk; Haruo Inoue
• Keywords: 02 engineering and technology; 0210 nano-technology

Intercalation of seven types of cationic surfactants, including polyfluorinated surfactants, into a cation-exchangeable clay mineral, saponite, was investigated. All of the surfactants were found to intercalate in amounts exceeding the cation exchange capacity (CEC). This tendency was more evident in the cases of the polyfluorinated surfactants, ((((perfluoroalkanoyl)amino)ethyl)hexadecyl)dimethylammonium bromide (CnF-S, where n indicates the number of carbons in the perfluoroalkyl group, F denotes a fluorinated surfactant, and S denotes a surfactant having a single, long alkyl chain); C3F-S exhibited intercalation up to 4.4 times CEC as a saturated adsorption limit. The saponite interlayer distance increased upon surfactant intercalation and reached a constant value at intercalation levels exceeding CEC. The occupied areas for each surfactant molecule decreased in the order C1F-S > C2F-S > C3F-S among the polyfluorinated surfactants. All of the experimental results, including the saturated intercalation ...