Silane Deposition via Gas-Phase Evaporation and High-Resolution Surface Characterization of the Ultrathin Siloxane Coatings

Siloxane coatings for surfaces are essential in many scientific and industrial applications. We describe a straightforward gas-phase evaporation technique in inert atmosphere and introduce a practical and reliable silanization protocol adaptable to different silane types. The primary aim of depositing ultrathin siloxane films on surfaces is to enable a reproducible and homogenous surface functionalization without agglomeration effects during the layer formation. To realize high-quality and large-area coatings, it is fundamental to understand the reaction conditions of the silanes, the process of the siloxane layer formation, and the possible influence of the substrate morphology. We used three typical silane types to exemplify the potential and versatility of our process: aminopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, and 1H,1H,2H,2H-perfluorooctyl-trichlorosilane. The ultrathin siloxane layers, which are generally difficult to characterize, were precisely investigated with high-resolution s...