AVS 53rd International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP30
Adsorption and Displacement of Cetyltrimethylammonium Bromide (CTAB) on Model Gold Surfaces

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Surface Science Poster Session
Presenter: S. Lee, Illinois Institute of Technology
Authors: S. Lee, Illinois Institute of Technology
V.H. Perez-Luna, Illinois Institute of Technology
Correspondent: Click to Email
The adsorption and displacement of the cationic surfactant, cetyltrimethylammonium bromide (CTAB) on model crystalline gold surfaces was studied. Adsorption of CTAB from aqueous media onto gold surfaces of different crystal orientations was studied by water contact angle measurements, spectroscopic ellipsometry, and FT-IR spectroscopy. Displacement of adsorbed CTAB molecules with 16-mercaptohexadecanoic acid (MHDA) from planar gold surfaces was performed using various MHDA concentrations and incubation times. The displacement reaction was also studied by water contact angle measurements, ellipsometry and FT-IR spectroscopy. The displacement of CTAB with MHDA on gold is evident in the decreased water contact angle upon formation of carboxyl terminated surfaces. FT-IR spectra also show differences indicative of the displacement reactions. Differences in adsorption and displacement behavior at various crystalline surfaces are especially relevant to adsorption and displacement reactions of surfactants and alkanethiols on anisotropic gold nanoparticles such as nanorods. These studies will yield new insights on strategies for surface modification of nanoparticles presenting different crystalline surfaces.