Synthesis, Physical Properties and Application of NaSbO3

Abstract

Present research work is based on development of an innovative method for synthesis of sodium antimonate using commercial grade (NaCl). There are few reports on the synthesis of this compound from expensive precursors. Present study aimed to produce NaSbO3 by Wet chemical synthesis of Sb2O5 followed by its solid state reaction with NaCl at 700°C, four different annealing temperatures (700, 800, 900, 1000°C) have been employed to investigate the structure and properties. Characterization by XRD revealed the purity, phase analysis and crystallite size of synthesized material and also indicated the change of single phase to multi phase at higher annealing temperature. Crystal structure obtained after Rietveld refinement is pyrochlore type, in that structure Na is present between the layers of Sb and O. SEM analysis exposed the same chemical composition and gave information about the morphology of NaSbO3. Material synthesized at 1000°C showed better morphological aspect as compared to other samples annealed at lower temperatures. Dielectric properties and AC conductivity have been measured at room temperature. It has been found that by increasing the annealing temperature, conductivity decreases because material is shifting from semiconductor to insulator. The value of optical band gap increased on increasing the annealing temperature which indicated that material becomes insulator at higher temperatures. NaSbO3 is subjected to hardness measurement by using micro Vickers hardness tester and material synthesized at 700°C exhibited maximum hardness. NaSbO3 is introduced as an additive into engine lubricating oil to check its effectiveness quality parameters of lubricating oils were measured after addition and compared with virgin oil. Flash point measurements have also been reported here, involving the effect of NaSbO3 concentration on the flash point of lubricating oil. Density, specific gravity and viscosity of lubricating oils after addition of little amount of NaSbO3 is measured and results obtained indicates elevation in density and specific gravity and viscosity of the lube oil decreases. Further research will prove NaSbO3 as a good additive for lubricating oil to enhance its flash point and has little effect on its density.