A new magnetic nano-adsorbent has been prepared based on graft copolymerization of vinyl acetate onto starch in the presence of magnetic nanoparticles followed by the sulfation of the hydroxyl groups using chlorosulfonic acid.

A magnetic nano-adsorbent was synthesized via the radical polymerization of methyl acrylate on modified Fe3O4 MNPs, followed by amidation of the methyl ester groups using pentaethylenehexamine, to create active sites for adsorption of anionic dyes.

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Due to the high activity of Au nanoparticles (NPs) for various reactions, many researchers have tried to develop heterogeneous catalysts in order to prevent irreversible agglomeration of Au NPs. Herein, magnetic graphene oxide modified with polyaniline (PANI) was used as a support for Au NPs that brings together advantages including: uniform dispersal of the catalyst in water,alarge surface area related to the graphene oxide; easy electron transfer in chemical reactions and good attachment of Au NPs to the support associated with PANI; and finally facile recovery in the presence of a magnetic field. Catalytic reduction of different analytes (Congo red, methylene blue, rhodamine B and 4-nitro phenol) was evaluated in the presence of NaBH 4 and the results show high catalytic activity of the catalyst. The catalyst was thoroughly characterized using various methods including FTIR, XRD, XPS, FE-SEM and HRTEM analyses while its catalytic activity was evaluated via reduction of different analytes.

Poly(amidoamine)-graft-poly(methyl acrylate) magnetic nanocomposite was synthesized via radical polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the functionalization of the methyl ester groups with poly(amidoamine) dendrimer. The resulting poly(amidoamine)-graft-poly(methyl acrylate) magnetic nanocomposite was then characterized by infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, scanning electron microscope and X-ray diffraction analysis. Its application as an adsorbent for the removal of Pb(II) ions was studied. The removal capability of the adsorbent was investigated in different pH values, contact time (kinetics) and initial concentration of lead. Moreover, adsorption isotherms were investigated to describe the mechanistic feature of this nanocomposite for adsorption. Accordingly, its high adsorption capacity (310 mg/g) and efficient adsorption toward lead ions in aqueous solution were shown. To further study of the chemistry behind the adsorption process, a comprehensive density functional theory-based study was performed, and a relatively strong interaction between metal ions and adsorbent was observed based on the calculated adsorption free energies.