Thermal insulation performance of novel orange fabric coated with Fe3+-doped La2Zr2O7 NIR solar reflectivity pigment. (15th September 2022) - Wang, Jieyu
Graphical abstract: Highlights: The coated fabrics by NIR pigment Fe 3+ -doped La2 Zr2 O7 were the first study. The synthesized Fe 3+ -doped La2 Zr2 O7 -coated fabrics present orange color, also have high NIR solar reflectance. Simulated experiments show that the designed coated fabrics has lower heat flux than other fabrics. The coated fabrics could be used in the fields of thermal insulation and energy saving. Abstract: Novel orange thermal insulation coated fabrics were prepared by applying La2 Zr2-x Fex O7-δ (0.00 ≤ x ≤ 0.25) pigments. The formation of Fe 3+ -doped La2 Zr2 O7 pigment was ensured by analyzing XRD and XPS patterns. The pigment samples have near-spherical particles with particle sizes between 30 and 70 nm. The NIR solar reflectance of the pigments is very high, ranging from 75.97 % to 96.18 %, and its change is caused by the variation in free charge carrier concentration. Doping with Fe 3+ ions makes the color of the pigment appear orange and reduces the band gap vaule from 5.17 eV to 2.32 eV, mainly attributed to the charge transfer transition of La 5d ↔ Fe 3d. The La2 Zr2-x Fex O7-δ -coated fabrics exhibit excellent orange color and outstanding NIR solar reflectance (R* = 51.08 % − 64.47 %). Experimental simulations revealed that the designed coated fabrics have lower internal surface temperatures, with a temperature difference of 7.9–14.7 ℃ compared to conventional orange coated fabric, which shows superb thermal insulation performance. The fastness of washing, acids, and alkalis was excellent for fabric. In conclusion, the La2 Zr2-x Fex O7-δ -coated fabrics can achieve thermal insulation and energy savings by means of NIR solar reflectivity pigments.