Synthesis of Fe3O4@SiO2@MPS@P4VP nanoparticles for nitrate removal from aqueous solutions

ABSTRACT In this study, synthesis of Fe3O4@SiO2@MPS@poly(4‐vinylpyridine) core‐shell‐shell structure was investigated as an efficient adsorbent for removal of nitrate ions from aqueous solutions. Fe3O4 nanoparticles were initially prepared by co‐precipitation method, then the surface of Fe3O4 was coated with SiO2 through a modified St öber method. Finally, the Fe3O4@SiO2 nanoparticles were modified by 3‐(trimethoxysilyl) propyl methacrylate followed by emulsion polymerization of 4‐vinylpyridine. The resultant material was acidified in HCl solution to be effective for nitrate removal. The synthesized sample was characterized by X‐ray diffraction, transmission electron microscopy, field‐emission scanning electron microscopy, Fourier‐transform infrared spectra, thermogravimetric analysis (TGA), and vibrating sample magnetometer. The removal efficiency was optimized for some experimental parameters such as pH, contact time, and amount of sorbent loading. The maximum predictable adsorption capacity was 80.6 (mg nitrate/g sorbent) at optimum conditions. Also, regeneration of the nitrate adsorbed particles was possible with NaOH solution. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44330.