Submicrometer Structure of Surface-Chemical Gradients Prepared by a Two-Step Immersion Method

Author(s): Morgenthaler, Sara M., Seunghwan Lee, Nicholas D. Spencer

Journal: Langmuir (2005) 22: 2706-2712.

Abstract:
Lateral force microscopy and microdroplet density measurements have been used to examine the microstructure of surface-chemical gradients of thiols on gold, prepared by a two-step immersion method. A single-component coverage gradient, generated by gradual immersion of a gold surface into a solution of a single thiol, yielded islands of ~25 nm in diameter at the end that had only been briefly immersed, whereas an increasingly continuous film was formed along the gradient. After saturation with a second thiol with a different end group, the structure generated during the initial immersion step was found to persist.