Influences of Cr content and heat treatment on the optical property of the green mica-nano CrO pearlescent pigment.

In the present work, green nano CrO-coated mica pigments were prepared by homogeneous precipitation. Structure, morphology, and optical properties were investigated by X-ray diffraction, thermogravimetric and differential thermal analysis, scanning electron microscopy, and colorimetric analysis. The results showed that an amorphous coating was synthesized and crystallized to CrO after heat treatment at 800°C. Average particle size of the coating was about 100 nm. The optical properties of the final pigment depended on the Cr content and heat-treatment temperature. The pearlescent index increased as chromium nitrate content increased and then decreased. Lower calcination temperature can cause lower L* value and pearlescent index. [ABSTRACT FROM AUTHOR]