Thermally stable pigments based on mixed metal oxides

Abstract

Purpose

This work aimed to prepare black transition metal oxide pigments to be used as solar absorbers in the solar selective and other industrial paints.

Design/methodology/approach

Mixed metal oxide CoCuMnO_x spinel pigments were synthesised via the sol‐gel route. These oxides, namely (I‐Co_0.50Cu_0.25Mn_0.25)O_x, (II‐Co_0.25Cu_0.50Mn_0.25)O_x and (III‐Co_0.25Cu_0.25Mn_0.50)O_x, were prepared with different molar ratios and annealed at 600, 800 and 900°C, respectively. The prepared oxides were characterised by infrared spectrometer (IS), differential scanning calorimetry analysis (DSC), X‐ray diffraction (XRD) and transmission electron microscope (TEM).

Findings

The prepared pigments have a spinel structure with the composition CoCuMnO_x. All synthesised pigments consisted of nano particles ranged from 10 to 80 nm. The optical properties showed high absorption and moderately low reflectance in the solar wavelength range.

Research limitations/implications

The prepared samples, used in the present work, were synthesized from cobalt sulphate, copper chloride and manganese chloride. The salts were dispersed in polyacrylamide as a precursor.

Practical implications

The prepared samples were thermally stable and had good optical properties. They could be used as absorber materials in the painting of solar collectors.

Originality/value

These thermally stable mixed metal oxides could be used in the painting of solar collectors. The three mixed metal oxides could be used as absorber materials for heating solar collectors due to their high absorption and moderately low reflectance in the solar wavelength range.

Citation

Fahim Abdel‐Mohsen, F. and Salah Aly Emira, H. (2013), "Thermally stable pigments based on mixed metal oxides", Pigment & Resin Technology, Vol. 42 No. 4, pp. 231-236. https://doi.org/10.1108/PRT-03-2011-0013