Near infrared reflectance properties of metal oxide nanoparticles

Powders of nanocrystalline metal oxides were compared with common macrocrystalline powders and minerals for their ability to reflect near-infrared light (NIR) (750-2500 nm). The nanocrystalline metal oxides were found to possess higher NIR reflectance values (similar to 15-20%) and this can be attributed to their smaller crystallite sizes coupled with smaller mean aggregate sizes in accordance with the Kubelka-Munk theory.