Study the Effect of Chromium and Antimony Doping on Physical Properties of Yellow Ceramic Nano Pigments Based on TiO2

In this study, nano yellow pigments were fabricated by doping of chromium and antimony elements into TiO2 using chemical precipitation and solid state method and after transforming them to ink, their printing performance on the ceramic surface were investigated. The precursor to doping antimony to white rutile structure of TiO2 was SbCl3, while Cr(NO3)3 and K2CrO4 were the precursors for chromium doping by solid state reactions. The fabricated nano pigments were characterization by x-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis which showed different morphology, structure and color. Particle sizes which were estimated by SEM image were between 50 to 170 nanometers which is appropriate for ink-jet printing on the ceramic. XRD results showed the pigment synthesized by Cr(NO3)3 (sample A) had a mono-phase compound while the sample synthesized by K2CrO4 (sample B) consisted of a multi-phase compound. The pigments were transformed to ink by milling method and using an ester media. After printing process, the ceramics were analyzed by Diffuse Reflectance Spectroscopy and colorimetric measurement (CIE L*a*b*). The h° value from colorimetric measurement of A nano pigment, was 76.59 while for B was 79.18. This shows better yellow color of B. After printing the prepared ink of each pigment, h° value changed to 69.59 for A and to 81.14 for B. Therefore, the ink of A nano pigment declined to golden yellow after printing while the ink of B nano pigment presented a pure and better yellow color.