Menue

Publications

Title Interfacial charge of organic thin films characterized by streaming potential and streaming current measurements
Date 26.10.2001
Number 9620
Abstract Self-assembled monolayers of alkanethiol compounds chemisorbed on flat gold surfaces were characterized by streaming potential and streaming current measurements in aqueous electrolyte solutions using a novel microslit electrokinetic setup. The alkanethiols analyzed were terminated with different functional groups. Depending on the type of alkanethiol used different mechanisms were relevant for the generation of interfacial charge: dissociation for thiols bearing ionizable surface groups and preferential adsorption of ions for methyl-terminated thiols. In all investigated cases, the zeta potential calculated from the streaming potential was significantly lower than the zeta potential obtained from the streaming current. This was due to a contribution of the conductivity of the underlying gold substrate to the surface conductivity. Based on the data obtained for the zeta potential and the surface conductivity, the surface charge of acidically functionalized monolayers was concluded to be compensated almost completely in the stagnant layer whereas for methyl-terminated monolayers a considerable part of the countercharge is localized in the diffuse, hydrodynamically mobile part of the electric double layer.
Publisher Colloids and Surfaces A: Physicochemical and Engineering Aspects
Identifier
Citation Colloids and Surfaces A: Physicochemical and Engineering Aspects 195 (2001) 97-102
DOI https://doi.org/10.1016/S0927-7757(01)00832-9
Authors Schweiß, R. ; Welzel, P. ; Werner, C. ; Knoll, W.
Tags

Back to list