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Adsorption Studies of Organophosphonic Acids on Differently Activated Gold Surfaces

Author:
Niegelhell, Katrin, Leimgruber, Simon, Grießer, Thomas, Brandl, Christian, Chernev, Boril, Schennach, Robert, Trimmel, Gregor, Spirk, Stefan
Source:
Langmuir 2016 v.32 no.6 pp. 1550-1559
ISSN:
1520-5827
Subject:
X-ray photoelectron spectroscopy, acids, adsorption, gold, infrared spectroscopy, isopropyl alcohol, surface plasmon resonance
Abstract:
In this study, the formation of self-assembled monolayers consisting of three organophosphonic acids (vinyl-, octyl-, and tetradecylphosphonic acid) from isopropanol solutions onto differently activated gold surfaces is studied in situ and in real time using multiparameter surface plasmon resonance (MP-SPR). Data retrieved from MP-SPR measurements revealed similar adsorption kinetics for all investigated organophosphonic acids (PA). The layer thickness of the immobilized PA is in the range of 0.6–1.8 nm corresponding to monolayer-like coverage and correlates with the length of the hydrocarbon chain of the PA molecules. After sintering the surfaces, the PA are irreversibly attached onto the surfaces as proven by X-ray photoelectron spectroscopy and attenuated total reflection infrared and grazing incidence infrared spectroscopy. Potential adsorption modes and interaction mechanisms are proposed.
Agid:
5775712