Thermal Oxidation of Iron on Clay to Obtain Clay-Nano Iron Oxide (II) Pigment: Evaluation of Thermal, Colorimetric and Electromagnetic Properties

In this research, nano-iron oxide was synthesized on the surface and between clay layers using sodium carbonate and iron nitrate after thermal oxidation in 400 ° C. X-ray diffraction from synthesized pigment showed the presence of nano-iron oxide II crystals on the surface of the pigment. Moreover, thermal measurement of nano-iron oxide-clay pigment showed an improvement of thermal stability in comparison with clay. SEM and EDX results showed the presence of chemical elements of Fe, Al and Si on the surface of clay. Reflectance properties of nano-iron oxide-clay pigment showed that the intensity of reflectance in visible region and lightness value of pigment is decreased which is due to deposition of iron oxide nano-particle in the final pigment compound. Results from electromagnetic test showed an increased electromagnetic absorbance in clay/nanoiron oxide pigment in comparison with clay. J. Color Sci. Tech. 8(2014), 1-11©. Institute for Color Science and Technology.