A Comparative Study on the Phase Structure, Optical and NIR Reflectivity of BaFe12O19 Nano-Pigments by the Traditional and Modified Polyacrylamide Gel Method

Barium hexaferrite (BaFe12O19) nano- pigment is a pigment with high near infrared reflection in the wavelength range of 1400-2500 nm. The BaFe12O19 nano- pigments were synthesized by the traditional and modified polyacrylamide gel method and characterized by thermogravimetric and differential scanning calorimetry (TG-DSC) analyses, X-ray powder diffraction (XRD), fourier transform infrared (FTIR), transmission electron microscopy (TEM), and UV-Visible spectrophotometer. The physicochemical properties of BaFe12O19 nanopigments are strongly dependent on the synthesis route. The introduction of carbon particles into the BaFe12O19 precursor accelerates the formation of BaFe12O19 phase, reduces its particle diameter and changes its color properties. The modified polyacrylamide gel method makes it possible to obtain a high efficient near infrared reflection BaFe12O19 nano- pigments with a solar reflectance SR>90%. The high near infrared reflection makes BaFe12O19 nano- pigments have potential applications in the field of heat shielding.