Effects of bimetallic nanoparticles Ag and TiO2 embedment on tellurite zinc–silicate glass: Self-cleaning characteristics

Abstract The optimum hydrophobic activity resembling the lotus effects could be achieved by the inclusion of bimetallic nanoparticles in the tellurite–based glass. We prepared and characterized the new self–cleaning tellurite zinc–silicate glasses embedded with the silver (Ag) and Titania (TiO2) nanoparticles (NPs) via the melt-quenching method. The surface morphology, self–cleaning, mechanical and thermal properties of the as–quenched samples were determined. The embedment of bimetallic nanoparticles (AgNPs and TiO2NPs) was found to enhance the water contact angle (WCA) to transform the glass from hydrophilic (86.27o for TZSTA1 glass) to hydrophobic (97.47o for TZSTA4 glass) followed by the reconversion into hydrophilic (81.84o for TZSTA6 glass) nature. The Young, Young-Dupre, Wenzel, and Cassie–Baxter model calculations were performed to complement the experimental results. The sample TZSTA4 prepared with 0.03 mol% of AgNPs revealed the optimal WCA of 97.47o (Young), 95.47○ (Wenzel) and 130.13○ (Cassie–Baxter); surface tension value of 0.1727 Nm-1 (for Young) and 0.1761 Nm-1 (for Wenzel). It is established that by controlling the Ag and TiO2 NPs contents, the hydrophobic and hydrophilic traits of the studied glassed can be tailored, thereby enabling the proposed glass compositions suitable for diverse self-cleaning applications.