AVS 51st International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP9
Solvent and Chain Length Dependence of the Conformational Order in Self-Assembled Dialkylammonium Monolayers on Mica

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: G. Haehner, University of St Andrews, United Kingdom
Authors: G. Haehner, University of St Andrews, United Kingdom
M. Zwahlen, University of St Andrews, United Kingdom
W. Caseri, ETH Zurich, Switzerland
Correspondent: Click to Email
The adsorption of cationic surfactants, for example alkylammonium compounds, can be employed to modify the surface properties of layered silicates, such as micas and clays. This process is of significant importance to many industrial applications, ranging from ore flotation in the mining industry and soil treatment to the pharmaceutical, household, food processing and cosmetics industry. The conformational order in adsorbed monolayer coatings is an important parameter for the reliable use of the layers. Dialkylammonium films on mica substrates prepared via ion exchange in solution can exhibit a high degree of order and orientation, similar to thiol-gold systems. We have studied the quality of such films on mica depending on the solvent and the alkyl chain length. Contact angle measurements, photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure spectroscopy (NEXAFS) were employed to characterize the adsorbed layer. A remarkable difference in the established conformational order was observed for films prepared from different solvents and with different chain lengths.