Influence of manganese ions on decolorization effect in glass samples prepared from rice husk ash

Abstract

This study investigates the impact of manganese ions on the decolorization effect of glass samples produced from rice husk ash with varying concentrations of manganese ions denoted by xMnO2 ( ranging from 0. 0 to 0. 5 mol% ) . The chemical formula of glass composition is represented as ( 55- x) SiO2 ( RHA) : 25B2O3: 10Na2O: 10CaO: xMnO2. The elemental composition analysis of rice husk ash reveals that it mainly composed of 92% , silicon by weight, suggesting its potential as a substitute for silicon dioxide or sand in glass production. This study further explored the physical and optical properties of the glasses. With increasing MnO2 concentration, there is a corresponding increase in density and refractive index, on the other hand, molar volume is decreas when increasing MnO2. Absorption spectra of MnO2 are not observable due to the presence of Fe2O3 in the rice husk ash. However, doping MnO2 into the glass samples induces an oxidation- reduction reaction, leading to reduced coloration of the glasses. Furthermore, color analysis using the CIE L*a*b* color space reveals that the glass sample doped with 0. 2 mol% of MnO2 has clearly and transparently (L* = 86.7148, a* = - 0.8538, b* = 2.7031). This suggests potential for the development of various colored glasses utilizing this sample.