Magnetic Materials Based on Iron−Silicon-Containing Frameworks

Polyferrophenylsiloxanes based on iron(III) chelate and polyphenylsiloxane with different siloxane-to-sodium hydroxide ratios have been synthesized under mechanochemical activation conditions. It has been shown that the polymer yield after precipitation with petroleum ether is 37–52%. The polyferrophenylsiloxane composition closest to the specified one has been obtained at the ratio Si : Na = 1. The resulting composites have been studied using IR spectroscopy, X-ray diffraction, gel chromatography, and thermogravimetry. An XRD study has shown the introduction of iron atoms into the siloxane structure. The presence of sodium ions during the reaction in subsequent syntheses has made it possible to bind the released acetylacetone and fabricate polyferrophenylsiloxane with a specified Si : Fe ratio. However, with a further increase in the hydroxide content, the Si : Fe ratio is violated. A study of the magnetic properties of polyferrophenylsiloxanes has shown that they are superparamagnets. After heating them to 600°C, magnetization increases sharply (magnetic saturation) and hysteresis is observed.