Enhancing Environmental Stability and Transparency of Glass Coatings Using Silica Nanoparticles in the Sol-Gel Process

Abstract

Sol-gel technology has long been recognized as a promising stabilization treatment for glass. However, the acidity of its formulations may pose challenges, particularly due to the potential for corrosive effects, making its application on ancient and artistic glass more complex and requiring a delicate balance between safeguarding its structural integrity and preserving its visual and historical significance. This study investigates the incorporation of silica nanoparticles into silica-based coatings to reduce the synthesis acidity and enhance anticorrosion protection. The sol-gel formulations, tailored to minimize their acidity (from ̴pH 1–2 to pH 4) and ensure optimal compatibility with glass surfaces, are combined with 50nm and 200nm silica nanoparticles and applied using dip-coating. Comprehensive analyses, including optical characterization, water contact angle measurements, and nanoindentation tests, reveals that composite coatings with 50nm nanoparticles, applied through a double-dipping process, significantly improves resistance to alteration. These coatings demonstrates superior protective performance compare to both pure silica coatings and composite compositions containing 200nm nanoparticles. Surface analyses further highlighted that incorporating nanoparticles allowed for precise control over the formation of alteration structures on glass surfaces. This approach effectively manage the development of alteration patina, offering a promising solution for mitigating ancient glass alteration while maintaining its aesthetic integrity.