Nanoskopie

The treatment of hydrophilic silicate glass surfaces with alkoxysilanes to produce hydrophobic surfaces is of great importance for many applications. Achieving high hydrophobicity has traditionally relied on fluorinated silanes, which increasingly need to be replaced by alternatives that are less harmful to human health and the environment. Solutions of 3-aminopropyltriethoxysilane (APTES) at millimolar concentrations in a water/isopropanol mixture represent a promising approach for modifying the surface properties of silicate glass. Owing to the low silane consumption, this strategy is advantageous from both resource-efficiency and environmental perspectives. In this study, siloxane films were formed on glass substrates via dip-coating through a self-organizing process using APTES at different degrees of hydrolysis. The morphology, chemical composition, and vibrational properties of the resulting layers were investigated using atomic force microscopy, contact angle measurements, and various vibrational spectroscopic techniques. The film thickness was determined to be on the order of a few nanometers. Although contact angle measurements indicate that the surfaces remain hydrophilic, the resulting films—functionalized with hydroxyl and amino groups—constitute a promising platform for subsequent modification toward hydrophobic glass surfaces.