Synthesis, optimization and investigation of properties of BaO-P2O5 and BaO-CaF2-P2O5 glasses with and without silver nanoparticles

Abstract

This thesis reports synthesis, optimization and investigation of properties of metaphosphate BaO-P2O5 and BaO-CaF2-P2O5 host glasses and these glasses embedded with silver nanoparticles. Host glasses were prepared by conventional melt-quenching technique. Taguchi based grey relational analysis was used in the present study to simultaneously optimize the multiple performance characteristics of CaF2 added ternary barium phosphate glasses. This method helped to obtain optimal parametric combination for best performance characteristics of samples with minimum number of experiments. The investigated physical, structural, mechanical, optical and thermal properties of samples indicated that these properties strongly depended on CaF2 content. The sample with optimized composition, 30 mol% BaO–20 mol% CaF2–50 mol% P2O5 showed improved physical, elastic, mechanical, optical and thermal properties with thermal stability parameter above 100 ◦C. Hence, the above mentioned glass is suitable for fiber fabrication. Glasses doped with silver oxide and tin oxide were prepared by conventional melt-quenching technique but following a different synthesis route, in which silver nanoparticles of different sizes were embedded upon subsequent heat treatment at different temperatures and time durations. The formation, growth and distribution of silver nanoparticles in the glass matrix appeared to be both temperature and time dependent. Evolution in optical properties of prepared glasses were examined to understand the mechanism of cluster development and growth of silver nanoparticles. Size, morphology and distribution of embedded silver nanoparticles in the glass matrix were investigated using transmission electron microscope (TEM). Noticeable improvement was observed in elastic and mechanical properties of glass-metal nanoparticle composite with increase in concentration and size of embedded nanoparticles, which could be attributed to the improvement in strength of glass matrix and ease of plastic flow.