Document Type : Full length
1 a. Department of Chemistry, Faculty of Sciences, University of Sistan and Baluchestan, Zahedan, Iran
2 b. Department of Chemical Engineering, Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Pearlescent pigments are a variety of pigments that can generate an optical pleasant appearance in the system because of the ability of easy parallel orientation of a large number of platelet-like particles. In the present work, the green pearlescent pigments based on mica (biotite) and mica-titania flakes covered with a thin film of nickel oxide were prepared with novel methods via the homogeneous precipitation of nickel acetate with sodium / potassium hydroxide, and in the presence of mica (biotite), titania, ammonium molybdate or mica-titania flakes. The synthesized pigments were characterized by means of X-ray diffractometery (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and X-Ray fluorescence (XRF) analyses. By comparing the XRD pattern of synthesized pigments with the mica base pattern, it is clear that the structure of the support does not change due to the layering on these bases. As these layers are hydroxide, oxide and chloride compounds. The XRF analysis shows that the nickel compound is layered well on the mica at 8.823%. The quantity and quality of the produced pigments by methods 1 and 2 were approximately the same. Consequently, due to commercial savings, method 1 was recommended for the preparation of the metallic pearl pigments and mica was known as the best support for the production of the pearlescent pigments by the introduced methods. Furthermore, TGA/DSC curve showed that the introduced pigments were stable up to 200 ˚C. The results showed good chemical resistance and pearl luster effects for the produced pigments.