Optimizing the synthesis of cobalt aluminate pigment using fractional factorial design

• Published in: Ceramics international 2015-01, Vol.41 (1), p.699-706
• Main Authors: Gomes, Y.F., Medeiros, P.N., Bomio, M.R.D., Santos, I.M.G., Paskocimas, C.A., Nascimento, R.M., Motta, F.V.
• Format: Article
• Language: English
• Subjects: CoAl2O4; Complex Polymerization Method (CPM); Fractional factorial design; Optimization; Pigment
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2014.08.125

The increasing use of experimental design techniques comes from the growing need to optimize products and processes while minimizing costs and maximizing efficiency, productivity and quality of products. Ceramic pigments have wide application in ceramic industries in which the quality and advanced properties of materials are widely investigated. However, studies are required to improve the procedure for obtaining cobalt aluminate (CoAl2O4) using the Complex Polymerization Method (CPM). With the objective of optimizing this method, a 2(5-2) fractional factorial design was performed using data from UV–vis spectroscopy analysis as a response surface. To determine the best conditions for obtaining (CoAl2O4) in this study, five factors were chosen as input variables at levels determined for this study: citric acid concentration (stoichiometric), pyrolysis time (h), temperature (°C), calcination heating time and rate (°C/min). Through statistical application in the process of obtaining CoAl2O4, it was possible to study which of these factors may have greater influence in optimizing the synthesis. The precursor powders were characterized using TG/DSC thermogravimetric analysis, and the calcined powders were analyzed using X-ray diffraction (XRD) and energy dispersive scanning electron microscopy (SEM/EDS) to confirm the structural and morphological aspects of CoAl2O4. It was found that with increased calcination temperature 700°C