Linear and nonlinear vibrational spectroscopy of surfactants at aqueous interfaces

COLL 96

Colin D. Bain1, Richard A. Campbell1, Phillip R. Greene1, and Mona Marie Knock2. (1) Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, United Kingdom, (2) Clorox Services Company, 7200 Johnson Drive, Pleasanton, CA 94588-8004
This talk will describe recent developments in our laboratory using three different forms of vibrational spectroscopy at three different types of interface. (i) Infrared reflectance spectroscopy from flowing liquid surfaces has been used to study adsorption at the air-water interface on sub-second timescales. Recent results from both pure and mixed surfactant systems will be presented. (ii) Evanescent wave Raman scattering has the sensitivity to yield spectra from nanometre-thick films without enhancement by electronic or plasmon resonances. Spectra from surfactant and lipid bilayers at the silica-water interface will be described. (iii) The application of sum-frequency spectroscopy to the liquid-liquid interface has been extended to a hydrocarbon surfactant adsorbed at the alkane-water interface. The SF spectra will be compared with spectra for similar surfactants at other hydrophobic interfaces.