Formation and Characterization of Self-Assembled Films of Sulfur-Derivatized Poly(methyl methacrylates) on Gold

Abstract

Poly(methyl methacrylate) copolymers containing sulfide-derivatized side chains have been synthesized, and their adsorption onto gold has been characterized using ellipsometry, X-ray photoelectron spectroscopy, contact angle, and infrared measurements. The film thickness obtained by spontaneous adsorption of these polymers from solution was found to be a function of solution concentration and the spacing of the derivatized side chains along the backbone. Probing these films by secondary exposure to a semifluorinated n-alkyl thiol reveals that fluorocarbon domains form readily on the gold surface, although films of the polymer with side chains every 10 repeat units are resistant to displacement. A 24-Å layer of this polymer is able to completely shield the presence of a significant fluorocarbon layer during contact angle measurements. © 1993, American Chemical Society. All rights reserved.