The preparation and characterization of NaWO3 particles for heat shielding by Taguchi optimization method

Abstract The synthesis of sodium tungsten oxides (NaWO 3 ) particles was accomplished to apply on the heat shielding film. In this preparation, Taguchi method with L 9 orthogonal array was used to optimize experimental conditions for the formation of NaWO 3 particles. Primary mean particle size and the standard deviation of NaWO 3 particles were considered as the characteristics. Concentration of sodium tungstate (Na 2 WO 4 ), concentration of sodium borohydride (NaBH 4 ), and pH value were selected as main parameters. As the result of Taguchi analysis in this work, the concentration of sodium tungstate was the most influencing parameter on the particle size and the standard deviation. The pH value had also principal effect on particle size and size distribution. The optimal conditions were determined by using Taguchi optimization design method and NaWO 3 particles with primary mean size (∼100 nm) were prepared. By the analyses of X-ray diffraction and UV–vis spectrum, it was found that the annealed NaWO 3 particles were more effective on heat shielding than non-annealed particles.