Archaeological and historical glass artefacts are subjected to different degradation phenomena depending on their chemical composition and on the environment to which they have been exposed. ¹ The formulation of coatings is an important active conservation strategy for protecting glass from further degradation. Even though sol-gel treatments based on tetraethylsilane (TEOS) have been under the interest of the research community for quite a long time, ² coating properties optimization and new possibilities of functionalisation are still extensively studied.³

In this work, we investigate the performance of alternative inorganic and hybrid inorganic-organic silica coatings obtained through sol-gel route with the aim of comparing their behaviour with plasma polymerized SiO_x and SiO_xC_yH_z coatings obtained through a novel atmospheric pressure plasma jet (APPJ) system specifically designed to meet conservation requirements. Coated silica-soda-lime glass samples were artificially aged in a climatic chamber and were characterised by optical microscopy (OM), contact angle measurements, UV-vis, SEM and AFM analysis performed before and after the artificial aging process.

The preliminary results showed that both sol-gel coatings and plasma polymerized treatments exhibit an efficient protective action against degradation phenomena. The formation of corrosion products is significantly reduced and optical properties of the underlying glass are well preserved with respect to the uncoated glass surface. Therefore, sol-gel coatings formulated in this work exhibit a valid strategy for glass conservation. APPJ treatments showed also great potential as an innovative conservative approach since it can ensure localised and precisely tailored interventions by adapting plasma parameters while operating in-situ, at room temperature and without the need of solvents or catalysts.