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

Abstract

In this study, synthesis of Fe 3 O 4 @SiO 2 @MPS@poly(4-vinylpyridine) core-shell-shell structure was investigated as an efficient adsorbent for removal of nitrate ions from aqueous solutions. Fe 3 O 4 nanoparticles were initially prepared by co-precipitation method, then the surface of Fe 3 O 4 was coated with SiO 2 through a modified St € ober method. Finally, the Fe 3 O 4 @SiO 2 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. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44330.

Surface Modification of Magnesium Ferrite Nanoparticles for Selective and Sustainable Remediation of Congo Red

“…41,42 The broad and strong band at ∼1060 cm −1 and the band at ∼794 cm −1 correspond to the stretching and bending vibration modes of the siloxane (Si−O−Si) group, respectively. 43,44 The vibration of metal oxides is also found at ∼552 cm −1 . 44 After surface functionalization by APTES, the characteristic FTIR bands detected in MgFe 2 O 4 @SiO 2 NPs are also observed, whereas the characteristic bands of APTES (e.g., C−H and N− H vibrations) are not readily evident.…”

Lanthanide-Doped Upconversion Nanoparticle-Cross-Linked Double-Network Hydrogels with Strong Bulk/Interfacial Toughness and Tunable Full-Color Fluorescence for Bioimaging and Biosensing

“…48 After coating of a silica layer, some new Siassociated peaks were observed in Figure S1B, including the amorphous silica Si−O−Si vibration at 1093 and 794 cm −1 , the Si−OH vibration at 950 cm −1 , free Si−OH groups at 3749 cm −1 , and hydrogen-bonded Si−water at 3420 cm −1 . 49 Furthermore, two new bands at 1722 and 1635 cm −1 were observed and assigned to the stretching vibration of double carbon bond (CC) and carbanyl group (CO) of MPS, respectively. Clearly, the presence of all these new peaks confirms that silica layers with pendent double bonds were successfully coated on the surface of three CSNPs.…”

Fe3O4@SiO2@sulfated boric acid as superparamagnetic and recyclable nanocatalyst‐assisted, one‐pot, pseudo four‐component synthesis of 5‐amino‐2‐aryl‐3H‐chromeno[4,3,2‐de][1,6]naphthyridine‐4‐carbonitrile derivatives

“…Magnetic core–shell structures of silica are of great interest to researchers from a wide range of disciplines, including catalysis, biotechnology/biomedicine, magnetic resonance imaging, data storage, and environmental remediation . In recent years, MNPs (e.g., Fe 3 O 4 ) have been extensively investigated as an inorganic catalyst support in the synthesis of organic–inorganic hybrid catalysts because of their good stability, easy synthesis and functionalization, and high surface area, as well as low toxicity and price …”