Colour tunable cool pigments based on TiZn2O4 inverse spinels

A new class of near-infrared (NIR) reflecting yellow and orange cool pigments based on TiZn2O4 inverse spinels were synthesized. The colour tuning in pure TiZn2O4 was made possible by the substitution of octahedral Zn2+ ions by Cu2+ and Fe3+ ions separately. By the incorporation of Cu2+ and Fe3+ ions into the inverse spinel lattice in varying amounts, a series of pigment compositions having colours ranging from greenish-yellow to reddish-brown was obtained. The developed pigments exhibited moderate to high NIR reflectance ranging from 47.61 to 87.81%. The TiZn2O4 based NIR reflecting pigment provided an interior 4.8 degrees C cooler than an uncoated roofed interior. Cu2+ and Fe3+ doped TiZn2O4 systems were found to be highly stable and eco-friendly cool pigment candidates capable of achieving better thermal conditioning and impressive energy conservation.

Automated summary

A new class of near-infrared reflecting yellow and orange cool pigments based on TiZn2O4 inverse spinels were synthesized. By adjusting the composition, a series of pigment compositions with colors ranging from greenish-yellow to reddish-brown were obtained. These pigments exhibited high NIR reflectance and had the ability to reduce indoor temperature, resulting in energy conservation.