Participation of Inclusion Complexes in the Surface Adsorbed Layer in Mixtures of α-Cyclodextrin and Cationic−Anionic Hydrogenated and Fluorinated Surfactants: A Surface Tension Proof

Autor: Hang Xing, Hongtao Zhou, Zhi-Ming Gou, Hai-Qian Yu, Jin-Xin Xiao
Rok vydání: 2011
Předmět:
Zdroj: Journal of Chemical & Engineering Data. 56:1423-1432
ISSN: 1520-5134
0021-9568
DOI: 10.1021/je101149h
Popis: It is generally considered that complexes of cyclodextrins (CDs) with ordinary surfactants are not surface-active in water. In this work, aqueous mixtures of α-CD, octyltriethylammonium bromide (OTEAB), and sodium perfluorooctanoate (SPFO) were studied by surface tension measurements. Comparison of the experimental results and the simulated ones in the premicellar region showed that the ability of the α-CD/OTEAB complexes to participate in the surface-adsorbed layer was dependent on the overall net charge of the surfactants: for the excess-SPFO system, the α-CD/OTEAB complexes did show a significant contribution to the surface activity of the mixture, but in the system with excess OTEAB, the α-CD/OTEAB complexes were not observed to influence the surface-adsorbed layer. We speculated that the surface-adsorbed layer in the premicellar region might also prefer an electroneutral state, as those cationic−anionic micelles did, and that the α-CD/OTEAB complexes were driven to the surface by electrostatic attrac...
Databáze: OpenAIRE