Aerosol-assisted process to produce sodium tungsten bronze particles from aqueous solutions and effect of particle size on the NIR shielding performance

An aerosol-assisted process using aqueous precursor solutions was introduced to produce crystalline sodium tungsten bronze particles. The replacement of organic solvents used in our previous process with water and the simplification of the experimental setup improved the scale-up of the proposed process. By the process, sodium tungsten bronze particles of Na0.7WO3 were produced in one step (seconds instead of hours by the liquid-phase methods). In this study, as-produced particles in different size ranges were further classified and collected by a MOUDI (i.e., Micro-Orifice Uniform Deposition Impactor). After the characterization of size-selected particle samples, the size range for the optimal NIR shielding while having an excellent visible light transmittance was identified. To the authors' knowledge, the effect of particle size on the NIR shielding performance of tungsten bronze particles was experimentally studied for the first time.