Superparamagnetic Composites Based on Ionic Resin Beads/CaCO /Magnetite.

The preparation of superparamagnetic composites obtained by CaCO mineralization from supersaturate aqueous solutions is presented. The preparation was conducted in the presence of oleic acid stabilized magnetite nanoparticles as a water-based magnetic fluid and insoluble templates as gel-like cross-linked polymeric beads. The presence of the magnetic particles in the composites provides a facile way for external manipulation using a permanent magnet, thus allowing the separation and extraction of magnetically modified materials. Two ion exchangers based on divinylbenzene/ethyl acrylate/acrylonitrile cross-linked copolymer-a cation ion exchanger (CIE) and an amphoteric ion exchanger (AIE)-were used, as well as different addition orders of magnetite and CaCO crystals growth precursors. The morphology of the composites was investigated by SEM, the polymorphs content by X-ray diffraction, and the thermal stability by thermogravimetric analysis. Polymer, CaCO , and magnetite in the composite particles were shown to be present by energy dispersive X-ray (EDX), XPS, and TEM. The sorption capacity for Cu ions was tested, as compared to samples prepared without magnetite.