Thiol-Based Self-Assembled Monolayers: Formation, Organization, and the Role of Adsorbate Structure

Self-assembled monolayers (SAMs) on solid substrates can be formed spontaneously from adsorbates such as alkanoic acids, alkyl silanes, and thiols. In particular, alkanethiolate SAMs on gold have been pursued because of the excellent bonding affinity between sulfur and gold, their reproducibility, and the ease of working with gold substrates. However, these SAMs are not stable at elevated temperatures, a concern that led to research on multidentate thiols to enhance SAM stability. To provide a complete picture of this thin film technology, we also examine basic concepts of monolayer formation kinetics; processes that occur in a fast and a slow regime.