Synthesis of porous magnetite Fe3O4 and its application in thermal control coatings as new black pigment

Abstract

In the present work, firstly, porous magnetite Fe3O4 was synthesized using mesoporous silica molecular sieve (SBA-15) as a template. Finally, the infiltrated ferrous precursor into silica mesopores was subjected to an infiltration process, in order to obtain the porous Fe3O4. The structural, morphological, and porosity characteristics and optical property of as-synthesized material were investigated by X-ray diffraction, field emission scanning electron microscopy, N2 adsorption, and diffuse reflectance spectroscopy. Evaluation of the obtained results indicated that the porous Fe3O4 has well-defined morphology and higher light absorption in the UV/Vis region than not only the common Fe3O4 and the other inorganic black pigments, but also common carbon black. Investigation of the prepared coating with this pigment indicated the higher absorption (0.98) and lower reflectance (~2%) than commercial black thermal control coatings (TCC) with inorganic pigments. This pigment presents the best selection for black TCC with inorganic pigment and stable in the space environment. The as-prepared porous magnetite Fe3O4 also has high surface area (~24.78 m2/g) and excellent magnetic properties (M s = 70 emu/g) at room temperature.