Development and performance evaluation of corrosion-inhibiting acidic solutions for soda-lime silicate glasses

Soda lime silicate glass is the most widely produced glass type in the world and is highly susceptible to corrosion, especially when stored or transported in humid, high-temperature environments. Soda lime glasses are more prone to corrosion than other silicate glass types due to the high alkali oxide content. Silicate glass corrosion is associated with alkali ion diffusion and corrosion occurs by two mechanisms; dealkalization on the glass surface and then dissolution of the network structure. Due to the surface modifications that occur in the corroded glass, its structural, optical and mechanical properties change. In this study, three sets of formulations were developed to prevent corrosion on glass surfaces under hot and humid conditions, applied onto the glass surfaces, and their performances were evaluated. In the first set of experiments, the corrosion prevention performance of three acidic aqueous coating systems consisting of organic acid (OAS), polymeric (PS) and polymeric organic acid (POAS) solutions was investigated. In the second set of experiments, eight different formulations were prepared by varying the polymer type, polymer concentration and the presence of zinc chloride and sodium metabisulfite as functional additives. In the third set of experiments, five different formulations were prepared with N-doped graphene quantum dots and graphene oxide by expanding the functional additives. The coatings were applied to soda lime glass surfaces by spray coating and then exposed to accelerated weathering conditions (50 °C, 95% relative humidity for 400 or 500 hours). Before the weathering test, the interactions of the formulations with the glass surface (surface tensions and contact angles of the formulations, coating topography, coating roughness, mechanical wear resistance) were examined. Following the weathering test and subsequent removal of the coating layers on glass surfaces, the corrosion protection performance was evaluated by examining glass surface roughness (AFM Ra), water contact angle, optical transmittance, haze, and qualitative methylene blue staining. Among the coating formulations tested in the first experimental step, the polymeric organic acid (POAS)-based formulation demonstrated the most effective protection of the glass surface. Compared to the uncoated reference, this formulation resulted in only a 33% increase in surface roughness, caused minimal change in contact angle, and led to negligible optical degradation. These findings highlight the critical importance of interfacial interactions between the coating and the glass surface, as well as the role of coating homogeneity in achieving long-term corrosion resistance. In this context, both the chemical structure of the polymer matrix and the type and concentration of additive components were found to directly influence the overall protective performance. In the second experimental step, a comparative analysis of the formulations revealed that polyvinyl alcohol (PVA)-based coatings outperformed polyethylene glycol (PEG)-based ones in terms of film integrity and surface protection. Notably, a strong correlation was observed between coating quality—specifically, surface uniformity and hydrophobicity—and corrosion resistance. Accordingly, the formulation composed of PVA in combination with ZnCl₂ and Na₂S₂O₅ emerged as the most effective anticorrosive system among all the tested variants. The results of the Taber abrasion test revealed that uncoated soda-lime glass surfaces are highly susceptible to mechanical wear. In contrast, the low roughness values measured for glass samples coated with POAS and the other formulation composed of PVA in combination with ZnCl₂ and Na₂S₂O₅ indicate that these coatings effectively protect the glass surface against mechanical stress. The results demonstrate that the developed coating formulations enhance the surface durability of the glass by minimizing damage caused by mechanical abrasion. In the third experimental study, polymer-based coating formulations utilizing polyvinyl alcohol (PVA) were developed and evaluated for the corrosion protection of soda-lime silicate glass surfaces. The formulations incorporated additives such as nitrogen-doped graphene quantum dots (N-GQD), graphene oxide (GO), ZnCl₂, and Na₂S₂O₅. Comprehensive physical, chemical, and optical analyses conducted after accelerated weathering tests demonstrated that formulations containing N-GQD and ZnCl₂ provided superior film homogeneity, enhanced hydrophobicity, and effective corrosion resistance on the glass surfaces. These findings highlight the critical role of carbon-based nanofillers in improving the durability and anticorrosive performance of polymeric coatings.