Superparamagnetic nanoarchitectures: Multimodal functionalities and applications

Sezer, Nurettin; Arı, İbrahim; Biçer, Yusuf; Koç, Muammer

doi:10.1016/j.jmmm.2021.168300

Cited by 28 publications

(10 citation statements)

References 610 publications

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“…In the future, magnetic jabon wood could become a superparamagnetism material. Such materials can be used in energy harvesting, heat transfer, and the adsorption and removal of contaminants such as heavy metals, dyes, and organic compounds [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

Fast-Growing Magnetic Wood Synthesis by an In-Situ Method

et al. 2022

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Jabon (Anthocephalus cadamba) is a fast-growing wood with low quality due to its low density and strength. The quality can be increased by modifying the wood through impregnation with various chemical compounds. In this study, jabon was impregnated with a solution of Fe and immersed in a strong base (NaOH) or a weak base (NH4OH) to form magnetite (Fe3O4) in-situ. This study analysed the use of NaOH and NH4OH in synthesising magnetic jabon wood and evaluated the wood’s characteristics. The impregnation process began with a vacuum of −0.5 bar for 0.5 h and then a pressure of 1 bar for 2 h. The samples subsequently underwent assessment of their dimensional stability, density, and characteristics. The results showed that impregnation with Fe solution followed by NaOH or NH4OH significantly affected the density and dimensional stability of the wood. The polymer weight gain was higher with NaOH, while the anti-swelling efficiency was higher with NH4OH. The density and bulking effect were increased, but the water uptake was decreased. Fourier transform infrared analysis showed the successful synthesis of magnetite. Scanning electron microscopy–energy-dispersive X-ray spectroscopy analysis revealed that magnetite covered the vessel fibre cell walls, and vibrating sample magnetometry analysis showed significant magnetic properties of the wood.

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Section: Introductionmentioning

confidence: 99%

Fast-Growing Magnetic Wood Synthesis by an In-Situ Method

et al. 2022

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“…This could be due to a smaller amount of PCysMA grafted on MgFe 2 O 4 surfaces compared to MgFe 2 O 4 @SiO 2 , as described in the TGA results. However, all hysteresis loops exhibited a near zero remanence and coercivity (see inset of Figure b), indicating superparamagnetic behavior. , In addition, the MgFe 2 O 4 /PCysMA and MgFe 2 O 4 @SiO 2 /PCysMA nanocomposites can be rapidly separated from the solution within a few minutes by using an external magnet, indicating an excellent magnetic response (see Figure c).…”

Section: Results and Discussionmentioning

confidence: 92%

“…However, all hysteresis loops exhibited a near zero remanence and coercivity (see inset of Figure 2b), indicating superparamagnetic behavior. 48,49 In addition, the MgFe 2 O 4 /PCysMA and MgFe 2 O 4 @SiO 2 /PCysMA nanocomposites can be rapidly separated from the solution within a few minutes by using an external magnet, indicating an excellent magnetic response (see Figure 2c). The morphologies of MgFe 2 O 4 and MgFe 2 O 4 @SiO 2 NPs before and after polymerization of the CysMA monomer were explored by FE-SEM and TEM, as shown in Figure 3.…”

Section: Characterization Ofmentioning

confidence: 99%

Magnesium Ferrite/Poly(cysteine methacrylate) Nanocomposites for pH-Tunable Selective Removal and Enhanced Adsorption of Indigo Carmine and Methylene Blue

Kunakham

Hoijang

Nguyen

et al. 2022

Ind. Eng. Chem. Res.

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Magnesium ferrite (MgFe 2 O 4 ) and silica-coated MgFe 2 O 4 nanoparticles were grafted with poly(cysteine methacrylate) (i.e., MgFe 2 O 4 /PCysMA and MgFe 2 O 4 @SiO 2 /PCysMA nanocomposites) to study pH-tunable adsorption and enhanced capacities for the adsorption of anionic indigo carmine (IC) and cationic methylene blue (MB) dyes. Several characterization techniques (i.e., XRD, FTIR, TGA, ζ potential analysis, VSM, FE-SEM, TEM, N 2 adsorption−desorption isotherm, and XPS) indicated successful syntheses of these nanocomposites. The adsorption behaviors of the dyes demonstrated that the PCysMA-modified nanoadsorbents could selectively adsorb either IC or MB from either single-component or binary dye systems if the initial pH of the dye solution was tailored appropriately (i.e., pH ∼2 for IC and pH ∼10 for MB). The selective adsorption of these dyes was proposed by the electrostatic attractions of the nanoadsorbents and the dyes. Adsorption isotherms also showed enhanced capacities of MgFe 2 O 4 and MgFe 2 O 4 @SiO 2 NPs for the adsorption of IC and MB after grafting with PCysMA. Interestingly, the MgFe 2 O 4 @SiO 2 /PCysMA nanoadsorbent provided highly pH-selective adsorption and large increases in the capacities for the adsorption of IC and MB, which were attributed to the amounts of PCysMA grafted onto different magnetic substrates. The coating of silica on the surfaces of magnetic nanoparticles provided a higher amount of 3-methacryloxypropyltrimethoxysilane, promoting the polymerization of CysMA monomer. Recycling tests indicated that high efficiencies (∼80%) for the adsorption of IC and MB by the PCysMA-modified nanoadsorbents were obtained after five adsorption−desorption cycles. These key findings showed that the MgFe 2 O 4 /PCysMA and MgFe 2 O 4 @SiO 2 /PCysMA nanocomposites exhibited excellent pH-tunable adsorption of anionic and cationic dyes, easy magnetic separation, good reusability, and high stability. Specifically, the MgFe 2 O 4 @SiO 2 /PCysMA nanocomposite offers highly pH-selective adsorption and high adsorption capacities for dyes, demonstrating promising and alternative nanoadsorbents for applications in wastewater treatment and sensors.

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“…Magnetic hysteresis loops of all samples revealed S-shaped curves with near-zero values of magnetic remanence and coercivity, indicating superparamagnetic behaviors existing in all samples (see Figure S2). Additionally, the saturation magnetization ( M S ) values of the pristine MgFe 2 O 4 -based supports decreased after surface modification with bimetallic Au/Ag NPs. The existence of nonmagnetic constituents (e.g., silica, Au, and Ag metals) resulted in the reduction of magnetization for the nanocomposites, attributed to the mass effect originating from those diamagnetic substances. , However, both MgFe 2 O 4 /Au/Ag and MgFe 2 O 4 @SiO 2 /Au/Ag NPs were rapidly separated within a few minutes by applying an external magnet as demonstrated by digital photographs in Figure .…”

Section: Resultsmentioning

confidence: 99%

Surface Deposition of Magnesium Ferrite-Based Supports with Bimetallic Gold/Silver Nanoparticles for the Catalytic Reduction of Nitroaromatics

Hoijang,

Kunakham,

Nonkumwong

et al. 2024

Langmuir

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Surface deposition of magnesium ferrite nanoparticles (MgFe 2 O 4 NPs) with bimetallic gold/silver (Au/Ag) nanoparticles was conducted using the seed-mediated growth method to obtain magnetic−metallic composite catalysts for use in the catalytic reduction of nitroaromatics. Two types of aminefunctionalized MgFe 2 O 4 and MgFe 2 O 4 @SiO 2 NPs were used as magnetic supports for the surface deposition process. The combination of several characterization analyses (i.e., XRD, XPS, TEM, SEM, EDS, and VSM) confirmed the successful syntheses of the MgFe 2 O 4 /Au/Ag and MgFe 2 O 4 @SiO 2 /Au/Ag NPs. The catalytic reduction of 4-nitrophenol using sodium borohydride as a reducing agent revealed that the reaction was completed within 2 min by using MgFe 2 O 4 /Au/Ag and MgFe 2 O 4 @SiO 2 /Au/Ag NPs as catalysts. The appearance rate constant of the MgFe 2 O 4 /Au/Ag NPs was slightly higher than that of the MgFe 2 O 4 @SiO 2 /Au/Ag NPs. In terms of reusability, high conversion (>80%) of the reduction of 4-nitrophenol was still obtained after 7 and 10 consecutive cycles for the MgFe 2 O 4 /Au/Ag and MgFe 2 O 4 @SiO 2 /Au/Ag catalysts, respectively. Interestingly, these two catalysts exhibited the highly catalytic conversion of the chosen nitroaromatic derivatives (i.e., 4-nitrobenzaldehyde and 4-nitroaniline). On the whole, the MgFe 2 O 4 /Au/Ag and MgFe 2 O 4 @SiO 2 /Au/Ag NPs could be utilized as suitable and sustainable catalysts for the catalytic reduction of nitroaromatics due to several desirable features (i.e., high activity, facile and rapid separation by a magnet, and good reusability).

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Superparamagnetic nanoarchitectures: Multimodal functionalities and applications

Cited by 28 publications

References 610 publications

Fast-Growing Magnetic Wood Synthesis by an In-Situ Method

Fast-Growing Magnetic Wood Synthesis by an In-Situ Method

Magnesium Ferrite/Poly(cysteine methacrylate) Nanocomposites for pH-Tunable Selective Removal and Enhanced Adsorption of Indigo Carmine and Methylene Blue

Surface Deposition of Magnesium Ferrite-Based Supports with Bimetallic Gold/Silver Nanoparticles for the Catalytic Reduction of Nitroaromatics

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