OPTIMIZATION OF COATING PROCESS OF HEMATITE NANO PARTICLES ON MICA FLAKES BY RESPONSE SURFACE METHODOLOGY

The present paper attempts as how the pigments comprising of nano-sized hematite particles deposited on mica surfaces in optimum conditions offer an excellent pearlescent properties. To record the influencing parameters on the synthesis process, response surface methodology (RSM) technique was used where temperature of reaction, synthesis time and concentration of urea were selected as variable parameters. Taking into account colorimetric parameters, the whole process was then analyzed by "Design Expert" software that finally gave following optimum factors: reaction temperature=82.02°C, synthesis time=11.98 h, urea concentration=37.5 g/l. Once the above optimum parameters selected, seemingly, the spherical hematite particles of about 60 nm in diameter are deposited uniformly on mica surfaces.