title: Dynamics of mixed surfactants in aqueous solutions.
abstract: The dynamics of mixed surfactants in aqueous solution has been studied at a molecular level by nuclear magnetic resonance (NMR) spectroscopy. The line widths and line shapes of the resonance peaks of two types of binary mixed surfactant systems, ionic/nonionic mixed solutions (12-2-12/TX-100, 14-2-14/TX-100, 14-2-14/Brij-35, and SDS/TX-100) and ionic/ionic mixed solutions (12-2-12/TTAB and 14-2-14/TTAB), in the (1)H NMR spectra offered semiquantitative results about the influence of mixing on the surfactant exchange dynamics between monomers in aqueous solution and those in the micelles. The results showed that the exchange rates of the mixed surfactants were enhanced by each other for the three cationic/nonionic mixed solutions, while the exchange rates were lowered by each other for the two cationic/cationic mixed solutions. As for SDS/TX-100 mixed systems, the addition of SDS made the exchange rate of TX-100 in solution faster, while TX-100 made the exchange rate of SDS slower. These results provide some information about surfactant interaction in mixed solutions.
authors.affiliation: Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Shizhen
authors.initials: S
authors.lastname: Mao
authors.forename: Pingya
authors.initials: P
authors.lastname: Luo
authors.forename: Youru
authors.initials: Y
authors.lastname: Du
authors.forename: Maili
authors.initials: M
authors.lastname: Liu