AVS 46th International Symposium
    Biomaterial Interfaces Group Monday Sessions
       Session BI-MoA

Paper BI-MoA8
Properties of Oligo(ethylene glycol)- Terminated Alkanethiolates on Gold: Influence of Lateral Hydrogen Bonding

Monday, October 25, 1999, 4:20 pm, Room 613/614

Session: Protein Solid-Surface Interactions I
Presenter: R. Valiokas, Linköping University, Sweden
Authors: R. Valiokas, Linköping University, Sweden
S. Svedhem, Linköping University, Sweden
S. Svensson, Linköping University, Sweden
M. Östblom, Linköping University, Sweden
U. Gelius, Uppsala University, Sweden
B. Liedberg, Linköping University, Sweden
Correspondent: Click to Email
An exhaustive study on properties of a class of oligo(ethylene glycol) (OEG)- terminated alkanethiolates on gold is presented. Contact angle goniometry, ellipsometry, infrared reflection-absorption spectroscopy, and X-ray photoelectron spectroscopy indicate formation of highly ordered self-assembled monolayers (SAMs), and the compounds containing amide moieties display lateral hydrogen bonding. The conformation of the OEG portion is shown to depend on the oligomer chain length and the lateral interactions, as evidenced by a different phase behavior of analogous OEG compounds which contain no amide group, as well as by using mixed SAMs of shorter and longer OEG chains. The assembly kinetics is found to be important in order to fine-tune the dominating phase of the SAMs. Furthermore, the thermal properties of the SAMs are investigated and temperature-dependent phase behavior is used to understand the nature of the conformational transitions of the OEG portion in relation to hydrogen bonding. Thus, the specifically introduced lateral interactions are shown to be not only a useful tool to improve the order and stability of the SAMs, but also to control conformational/functional properties of terminal groups which in this case are oligomers. Possible further modifications of such OEG SAMs and their bio-oriented applications are discussed.