Anticorrosive ceramic pigment based on nanocrystaline

CoO doped ZnO

Sousan Rasouli ^*, Shirin Gebeli Moeen and Amir. M. Arabi

Department of Nanotechnology, Institute for Colorants, Paints & Coatings, 59 Vafamanesh Ave., HosseinAbad Square, Pasdaran St, 1668814811, Tehran, Iran

^* rasouli@icrc.ac.ir

Abstract

In this work, the microwave–assisted gel combustion was used for synthesis of 0.1 mol percent CoO doped ZnO. The powder properties are investigated by x-ray diffraction, Simultaneous thermal analysis, Colorimetric method and Transmittance Electron Microscopy. Electrochemical testing was used for investigation of the corrosion resistance of the pigment.

Zn (NO₃)₂.6H₂O, Co(NO₃)₂.6H₂O as a oxidant and citric acid as a fuel and complexing agent were used. All the raw materials were in Analytical Grade.

After adding metal nitrates and citric acid in stoichiometric amount to deionized water into beaker vessel and heating a highly viscous precursor gel was gained. The combustion reaction is completed in the microwave oven.

The structure of product was investigated by x-ray diffraction and results show that combustion reaction completed more vigorously in fuel-lean region. Crystallite size changes in the range between 27-37.2 nm depending on the amount of fuel content.

Color properties of ZnO-10%CoO pigment was investigated by a 7000 A spectrometer in the range between 350 and 750 nm and the diffuse reflectance spectra of the synthesized pigments was obtained. A broad absorption band around 540 nm (green region) can be observed. It is also shown that, depending on fuel content, different color properties can be obtain which ascribed to powder particle and state of agglomeration.

With regard to corrosion protection properties, it was observed that paint films containing only 2 percent weight of pigment showed good anticorrosion performance.

Keyword: Combustion, Microwave-assisted, ZnO, pigment, anticorrosive