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CP: Chemische Physik
CP 17: Postersitzung Transportprozesse durch Grenzflächen und Membranen
CP 17.2: Poster
Tuesday, March 18, 1997, 18:30–21:15, FBH
Monolayers of Gold Nanoparticles: Influence of Lateral Density and Deformation on the Optical Properties — •Peter Mächtle1, Dirk Eck1, Johannes Schmitt2, and Christiane A. Helm3 — 1Institut für Physikalische Chemie, Johannes Gutenberg-Universität, 55099 Mainz — 2Universite Louis-Pasteur and CNRS Strasbourg, France — 3Fachrichtung Kristallographie, Universität des Saarlandes, 66041 Saarbrücken
Negatively charged gold colloids dissolved in aqueous solution are adsorbed onto positively charged solid surfaces. The adsorption kinetic is determined by the bulk diffusion constant. The thickness and the area per particle of the gold particles is determined by SAXS-, UV-Vis and AFM-measurements. The absorption properties depended further on the dielectric constant of the medium surrounding the monolayer. Two surfaces coated with nanoparticles are mounted in the surface forces apparatus, where the interaction force between the surfaces is monitored as well as the optical absorption. Under relativitely small compressive pressures (below 1 atm) the gold particles start to flatten and possibly to interact laterally, until a homogeneous thin film is formed. This deformation is irreversible.