Impact of synthesis method on the properties of near-infrared region-reflective SrSn0.9Mn0.1O3 brown pigment

Abstract

Brown near-infrared region (NIR) reflective pigment of SrSn0.9Mn0.1O3 was prepared using four different methods: the classical ceramic method, both wet and dry mechanochemical activation processes and the precipitation method. The pigments were characterised in terms of colour properties, NIR reflectivity, phase composition, particle size distribution and particle morphology. The prepared powders were applied to the organic matrix in mass tone, and their resulting colour hues shifted from copper brown via chocolate brown to dark brown. The NIR solar reflectance was calculated in the wavelength interval of 700–1650 nm following the ASTM 173-03 standard and their values of powder form were 25%–44%. The colour hue and NIR solar reflectance were dependent on the calcination temperature and the preparation method. The optimal condition for the preparation of the most NIR-reflective saturated brown pigment is the precipitation method and a temperature of 1050 °C (Rsolar = 42%; Cpowderform = 18.4), with an interesting matchstick shape of particles.