Study the physical properties of two green pigments based on chromium oxide

A suspension of green pigments of Cr2O3 and CoCr2O3 were prepared by polyol method and they were compared. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV/Visible transmission spectra, zeta potential measurement and particles size distribution of the pigments suspended in the solution and colorimetry analysis. The results of analysis show that Cr2O3 and CoCr2O4 are crystallized in a single-phase structure. SEM images show morphology of the samples is composed of nano pigments and the size distribution of the suspended nano pigment were determined to be about 9-17 nm. The stability of CoCr2O3 suspension is good for using as ink, while Cr2O3 suspension is relatively stable.