Study on Physical and Optical Properties of Nickel Oxide-Doped Glasses Derived from Waste Sugarcane Leaf Ash

Abstract

This research aims to study the physical and optical properties of glasses prepared from waste sugarcane leaf ash doped with nickel oxide (NiO). Sugarcane leaf ash was utilized as a source of silica (SiO2) and calcium oxide (CaO) to replace pure chemicals in the glass system: 60SiO2: (15-x)B2O3: 5BaO: 10CaO: 10Na2O: xNiO, where x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05 mol%. The glass samples were prepared using the conventional melt-quenching technique at 1,200°C and annealed at 500°C. Chemical composition analysis of the sugarcane leaf ash via the EDXRF technique revealed SiO2 and CaO as the primary constituents at 66.77% and 17.26% by weight, respectively. As the concentration of NiO increased, the density of the glass tended to decrease from 2.8756 to 2.8361 g/cm3. Conversely, the molar volume increased from 22.2437 to 22.5562 cm3/mol. This is due to the expansion of the glass network structure resulting from the increase in non-bridging oxygen (NBO). This correlates with the refractive index, which showed a downward trend consistent with the Lorentz-Lorenz theory. Optical property analysis showed distinct absorption peaks at wavelengths of approximately 442 and 640 nm. These peaks are associated with the energy level transitions of Ni2+ ions within an octahedral coordination structure. This results in the glass appearing yellowish-brown. Specifically, the brightness (L*) decreased, while the yellowness (+b*) increased in relation to the amount of NiO doping. These findings indicate the feasibility of developing sugarcane leaf ash into colored glass materials for unique decorative or optical applications.