Functionalization of ceramic tile surface by sol-gel technique.

Improving the cleanability of ceramic surfaces remains a challenge in industrial applications. While unglazed ceramic tiles are valued for their durability, they often struggle with dirt accumulation and cleaning efficiency. Prior research has shown that surface modifications can enhance functional properties, but few studies have explored sol-gel-derived coatings specifically for ceramic tile surfaces. Existing approaches often focus on glazed surfaces or fail to account for aesthetic preservation. This gap motivated the exploration of nanostructured coatings that could simultaneously improve cleanability and maintain visual appeal. No prior work had resolved how to balance photocatalytic activity with color stability on unglazed tiles. The need for a scalable and aesthetically neutral solution led to the investigation of TiO₂-SiO₂ films. This paper introduces a novel approach using sol-gel processing to address these challenges. The study builds on established sol-gel methodologies but applies them to a less-studied ceramic application.

The study aimed to develop a surface functionalization method for unglazed ceramic tiles using sol-gel processing. The primary goal was to enhance the cleanability of these tiles without compromising their appearance. A secondary objective was to evaluate how thermal treatment affects the photocatalytic properties of the coatings. The researchers proposed using TiO₂-SiO₂ binary films, as these materials are known for their photocatalytic and structural properties. The motivation stemmed from the need for durable, low-maintenance ceramic surfaces in industrial settings. The study also sought to preserve the tiles' aesthetic qualities through controlled thermal treatment. The researchers hypothesized that varying TiO₂ content and curing temperatures would influence coating performance. This approach allows for a systematic evaluation of material and thermal parameters in functional coating design.

The study employed sol-gel processing to create TiO₂-SiO₂ binary films on ceramic tiles. Tetraethoxysilane and TiO₂ nanoparticles were used as precursors to formulate the sol-gel solution. The films were applied via air-brushing onto polished unglazed tiles. Three different TiO₂ concentrations—1, 2, and 5 weight percent—were tested to assess their impact on coating properties. After deposition, the films underwent thermal treatment at temperatures ranging from 100 to 600 degrees Celsius. Scratch tests were conducted to evaluate coating adhesion to the tile surface. Photocatalytic activity was assessed using contact angle measurements and cleanability tests under UV exposure. Aesthetic changes were quantified through UV-visible spectroscopy and colorimetric analysis. These methods allowed for a comprehensive evaluation of functional and visual properties.

The highest photocatalytic activity was observed in films with 5 weight percent TiO₂ after thermal treatment at 600 degrees Celsius. Contact angle measurements indicated improved hydrophilicity, suggesting enhanced cleanability. Scratch tests revealed strong adhesion between the coatings and tile surfaces, with no significant delamination observed. Cleanability tests showed a reduction in dirt accumulation, particularly in the 5wt% TiO₂ samples. Colorimetric analysis indicated minimal hue variation, preserving the tiles' aesthetic appearance. UV-visible spectroscopy confirmed that the coatings did not significantly alter the tiles' optical properties. The thermal treatment at 600 degrees Celsius maximized photocatalytic efficiency without compromising coating integrity. These findings suggest that higher TiO₂ content and elevated curing temperatures enhance functional performance.

The study demonstrated that sol-gel-derived TiO₂-SiO₂ films can effectively enhance the cleanability of unglazed ceramic tiles. The authors propose that 5 weight percent TiO₂ and thermal treatment at 600 degrees Celsius optimize photocatalytic activity. The results suggest that these conditions improve hydrophilicity and dirt removal efficiency. The findings also indicate that aesthetic properties remain largely unaffected by the coating process. The researchers propose that the method is scalable for industrial applications. The study highlights the importance of thermal treatment in determining coating performance. The authors suggest that further work could explore long-term durability and environmental stability. These conclusions align with the study's aim to develop a functional coating that balances performance and appearance.