Comparing three methods of simultaneous synthesis and stabilization of Fe3O4 nanoparticles: Changing physicochemical properties of products to improve kinetic and thermodynamic of dye adsorption

Fe3O4 nanoparticles (FNPs) were synthesized by conventional heating(CH), co-precipitation(CP) and microwave heating(MH) methods in presence of pectin crosslinked by beta-isopropylglutaric acid(-CP) to stabilize nanoparticles. The role of the cross-linked pectin and kinds of synthesis methods was appeared to increase the effective total surface of FNPs both simultaneously as the synergistic effects and separately. The effective role of the microwave irradiation to decrease FNPs mean size was seen, so that its size in FMH was smaller 21.5% and38.2% than that of FCP and FCH, and in FMH-CP was smaller 27.2% and 58.9% than that of FCP-CP and FCH-CP, respectively. The various experiments were done on the structures, functional groups, and connection quantities of-CP to FNPs synthesized by CH, CP and MH methods. The different physical properties of the obtained composites containing magnetization, zeta potential and thermal analyses were determined. To study the adsorption of methylene blue(MB) from the aqueous and alkali solution, the role Fe-O- groups of FNPs was evaluated more effective than the role of -COO- and -O- of -CP in the stabilized nanoparticles. Fe3O4 NPs stabilized by-CP using microwave heating showed the highest capacity of MB adsorption due to having the most suitable ther- modynamic and kinetic parameters. (C) 2016 Elsevier B.V. All rights reserved.