Evaluating and optimizing the quality of silane-based self-assembled monolayers

Self-assembled monolayers (SAMs) form spontaneously through the adsorption of surfactant molecules onto surfaces, forming ordered molecular assemblies due to a specific affinity of the molecule‘s headgroup to these surfaces. Monolayers are a simple means of modifying the properties of surfaces, which can be important to many fields. It is, however, still a challenge to achieve high quality SAMs using alkylsilane-based molecules. In this thesis, high quality monolayers of alkylsilanes are sought through the use of mono-reactive perfluoroalkylsilanes. Monolayers created by the deposition of monoreactive perfluoroalkylsilanes from toluene solutions were investigated to correlate the quality of these SAMs to changes in their processing conditions. Surface sensitive spectroscopic techniques were used to monitor and guide further improvements in the quality of these monolayers. Changes to the process conditions included altering the solution temperature, silane concentration, and reaction times. Initial work is also presented on the use of microwave processing to significantly decrease the time required to form monolayers from mono-reactive perfluoroalkylsilanes. As a demonstration of the potential utility of these SAMs, we analyzed the ability of the silane-modified surfaces to resist the non-specific adsorption of proteins. In this example, the non-specific adsorption of bovine serum albumin (BSA) was evaluated on surfaces coated with perfluoroalkylsilane monolayers.