Advances on magnetic polymeric styrene-divinylbenzene nanocomposites between magnetite and maghemite nanoparticles: An overview.

Superparamagnetic nanoparticles such as magnetite (Fe3O4) and maghemite (γ-Fe2O3) have been used to produce magnetic nanocomposites with several polymeric matrices, such as magnetic styrene-divinylbenzene nanocomposites. Through the incorporation of these nanoparticles, the nanocomposite presents the phenomena of superparamagnetism, low coercivity and high magnetic susceptibility. Due to these features, magnetic nanomaterials can be removed from the place where they are inserted through an external magnetic field, thus differentiating them from conventional systems such as those used for treating oily water that require high costs of chemical agents for removal. These properties depend directly on the size distribution of the nanoparticles and on the presence or absence of interactions between the surface of the polymeric matrix and the contaminants. These materials have many applications and for this purpose the objective of this work is to present a bibliographic review and state-of-the-art of the evolution of magnetic styrene-divinylbenzene nanocomposites over the years. According to the reports in the literature, these systems are superior to those applied conventionally in the sectors of biotechnology, agriculture, oil/gas, and nuclear chemistry, mainly for the removal of toxic metals from aqueous media