Magnetic-field-induced self-assembly of FeCo/CoFe<sub>2</sub>O<sub>4</sub> core/shell nanoparticles with tunable collective magnetic properties

Mohapatra, Jeotikanta; Elkins, Jacob; Xing, Meiying; Guragain, Deepa; Mishra, Sanjay R.; Liu, J. Ping

doi:10.1039/d1nr00136a

Cited by 20 publications

(13 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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: 98%

See 1 more Smart Citation

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.

View full text Add to dashboard Cite

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.

show abstract

Section: Results and Discussionmentioning

confidence: 92%

Section: Characterization Ofmentioning

confidence: 98%

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.

View full text Add to dashboard Cite

show abstract

“…(3). A broad range of superlattices have been discovered from the self-assembly of metal (4), metal oxide (5), chalcogenide (6), core-shell (7), semiconductor NPs (8) and binary systems (9)(10)(11). Among these different materi-als, gold NPs can serve as a model system since they have original plasmonic properties that depend on their organization (12).…”

Section: Introductionmentioning

confidence: 99%

Gold nanoparticle superlattices: conditions for long range order, Moiré patterns and binary phase from a single population

Moretti

Goldmann

Impéror‐Clerc

et al. 2022

Preprint

View full text Add to dashboard Cite

We report the two-dimensional self-assembly at the liquid-air interface of spherical gold nanoparticles (NPs) with diameters between 2 and 14 nm. By exploring the self-assembly conditions, such as the dispersing solvent and the coating ligand (thiols with different lengths, oleylamine, polystyrene), we identify suitable conditions for long range close-packed monolayers obtention. We show that though NPs with diameters below 3 nm yield glassy films or fuse during self-assembly depending on the ligand length, NPs with larger sizes dispersed in toluene yield well-ordered monolayers over distances that can span tens of micrometers. Adding free ligand in solution before the self-assembly triggers long range ordering into close-packed structures of otherwise amorphous films. The equilibrium distance between the NPs within the monolayers are compared to predictions by the OPM and OCM geometrical models. We also observed a CaCu5 phase in few-layers assemblies which results from the size segregation of a single monodisperse population of NPs into two populations of different mean sizes occupying the two different sites of this complex lattice. In some instances, Moiré patterns consisting of two close-packed hexagonal monolayers superimposed with a twist angle are evidenced. By comparing the experimental structures with numerically simulated patterns, we show that a twist angle of 30° yields a quasicrystalline order with a 12-fold rotational symmetry. Our work provides insights into fundamental processes behind the self-assembly of colloidal nanocrystals into ordered mono- and few-layers as well as more complex assemblies such as quasicrystalline or Frank-Kasper phases. These structures are of great significance for bottom-up fabrication of functional devices that advantage of (collective) plasmonics properties or surface enhanced raman scattering.

show abstract

“…In particular, designing supercrystal or dynamic aggregates with external stimuli is an attractive assembly strategy . For example, magnetic FeCo/CoFe 2 O 4 core/shell NPs can be used for constructing oriented superlattices and tuning the collective properties using an external magnetic field . Similarly, a highly oriented 3D superlattice can be obtained by drying silver (Ag) nanocrystals in a toluene solution under an electric field .…”

mentioning

confidence: 99%

“…20 For example, magnetic FeCo/CoFe 2 O 4 core/shell NPs can be used for constructing oriented superlattices and tuning the collective properties using an external magnetic field. 21 Similarly, a highly oriented 3D superlattice can be obtained by drying silver (Ag) nanocrystals in a toluene solution under an electric field. 22 These ordered supercrystals have new collective properties that are not present in individual nanocrystals or bulk materials.…”

mentioning

confidence: 99%

Interfacial-Shear-Mediated Snowball Assembly of Hotspot-Rich Silver Pompon Architectures for Tailored Surface-Enhanced Raman Scattering Responses

Luo

et al. 2022

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

To gain superior signal-enhanced performance, metal nanocrystals serving as building blocks can be collectively assembled into a hierarchically ordered structure for creating multiple hotspots. However, the collaborative assembly of anisotropic crystals to form a hotspot-rich structure remains a challenging task. In this study, controllable shear was introduced to a soft liquid−liquid interface to provide a unique environment for the snowball assembly of silver pompon architectures (Ag-PAs). Micrometer-scale 3D plasmonic Ag pompon architectures composed of densely packed nanoparticles (NPs) are fabricated using shear-mediating crystal growth dynamics. The crystal morphology and size are easily controlled by tuning the interfacial shear and diffusion pathways. The hotspot-rich Ag-PAs with high sensitivity (LOD = 1.1 × 10 −13 mol/L) exhibit a superior Raman enhancement performance, which is comparable to some bimetals.

show abstract

Magnetic-field-induced self-assembly of FeCo/CoFe₂O₄ core/shell nanoparticles with tunable collective magnetic properties

Abstract: Self-assembly of nanoparticles into ordered patterns is a novel approach to build up new consolidated materials with desired collective physical properties. Herein, nanoparticle assemblies of composition-modulated bimagnetic nanoparticles have been...

Cited by 20 publications

References 59 publications

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

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

Gold nanoparticle superlattices: conditions for long range order, Moiré patterns and binary phase from a single population

Interfacial-Shear-Mediated Snowball Assembly of Hotspot-Rich Silver Pompon Architectures for Tailored Surface-Enhanced Raman Scattering Responses

Contact Info

Product

Resources

About

Magnetic-field-induced self-assembly of FeCo/CoFe2O4 core/shell nanoparticles with tunable collective magnetic properties

Abstract: Self-assembly of nanoparticles into ordered patterns is a novel approach to build up new consolidated materials with desired collective physical properties. Herein, nanoparticle assemblies of composition-modulated bimagnetic nanoparticles have been...

Cited by 20 publications

References 59 publications

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

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

Gold nanoparticle superlattices: conditions for long range order, Moiré patterns and binary phase from a single population

Interfacial-Shear-Mediated Snowball Assembly of Hotspot-Rich Silver Pompon Architectures for Tailored Surface-Enhanced Raman Scattering Responses

Contact Info

Product

Resources

About

Magnetic-field-induced self-assembly of FeCo/CoFe₂O₄ core/shell nanoparticles with tunable collective magnetic properties