Production of nano sized Co-ferrite pigments and detrmining the effect of milling proccess to pigment properties

In this thesis report, the production of nanosize black Co ferrite (CoFe2O4) pigment which has high thermally and chemically stability was studied. Therefore, the aim of the study is to produce the CoFe2O4 pigment by conventional ceramic method, to reduce the particle size to nanoscale by alternative grinding techniques and to investigate the grinding parameters. Additionally, nanosize CoFe2O4 pigment was produced by nonconventional co-precipitation method and color properties of this pigment was compared with milled nanosize pigment. Black CoFe2O4 pigment was synthesized by ceramic method with Co3O4 ve Fe2O3 at 1200oC with 800 nm particle size. In addition, CoFe2O4 pigment was synthesized with the grain size of 58 nm by co-precipitation method from the aqueous solutions of CoCl2.6H2O and FeCl3 than was calcined at 800 oC. According to sedimentation tests that was carried out before milling the most appropriate medium contains DEG as medium and 2.5 wt.% STPP as dispersant. The mean particle size of pigments produced by conventional method, was reduced to 190 nm after 4 h grinding by planetary mill whereas, 465 nm of particle size was obtained with attrition milling in same time interval. In conclusion, nanosize CoFe2O4 black pigments which has an application potential in ceramic ink-jet inks was successfully produced by grinding without any colour deterioration considering to inks used in inkjet printing having about 200-400 nm particle size.