Surface properties of aminopropylsilsesquioxane coatings for glass vials

Preserving the surface integrity of glass vials during production and filling is a key challenge for the glass packaging industry. In this study, thin aminopropylsilsesquioxane coatings were deposited from aqueous solutions on the external surface of glass vials and employed as a functional primer, providing a sustainable and eco-friendly alternative to conventional surface protection and lubrication strategies. The influence of organosilane concentration, immersion time, and post-deposition rinsing on film formation was investigated. Atomic Force Microscopy and Scanning Electron Microscopy analyses revealed nanoscale surface features and an increase in roughness from approximately 0.16 ± 0.02 nm for uncoated glass to about 0.34 ± 0.03 nm for samples coated with 1% (v/v) concentrated solution, consistent with a coating thickness of approximately ~8–10 nm estimated from X-ray Photoelectron Spectroscopy. This technique also confirmed the presence of amino functional groups capable of anchoring lubricants, while tribological tests showed that the aminopropylsilsesquioxane primer effectively coupled with a lubricating top coat, reducing the coefficient of friction below 0.2, although partial lubricant detachment occurred under repeated sliding. Overall, these results demonstrate that water-based organosilane primers can provide a sustainable and effective approach for the development of functional glass coatings in packaging applications.