Stability and Self-Cleaning Properties of Superhydrophobic Glass Coated with Halloysite Clay Nanotubes, Titanium Dioxide, and Silver-Titanium Dioxide Nanocomposite

The unique properties of superhydrophobic surfaces are explored for various applications. In this study, superhydrophobic nanostructured surfaces are fabricated on glass substrates using titanium dioxide (TiO₂), silver-coated titanium dioxide (Ag-TiO₂), and halloysite clay nanotubes (HNTs). The noble metal, silver (Ag, 0.5 wt.%) is loaded onto TiO₂ by the photodeposition method. Characterization techniques, including X-ray diffraction, Raman, and Fourier-transform Infrared spectroscopy, confirm the formation of the nanocomposites. The thermogravimetric analysis demonstrates thermal stability, and optical microscopy reveals an even distribution of the nanocomposite on the glass substrate. Nanocomposites of HNT-Ag-TiO₂ and HNT-TiO₂, with varying percentages of HNTs, are synthesized and spray-coated onto a glass substrate while modified with myristic and stearic acid. A superhydrophobic contact angle of 159.35° ± 2.7° and a sliding angle of 8° is obtained for HNT-TiO₂-stearic acid with 66.67 wt.% TiO₂. Additionally, HNT-TiO₂-stearic acid exhibits excellent chemical, mechanical, and thermal stability. The nanocomposite also displays self-cleaning properties, effectively shedding kaolin and carbon black contaminants.