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Andreu I, Urtizberea A, Natividad E. Anisotropic self-assemblies of magnetic nanoparticles: experimental evidence of low-field deviation from the linear response theory and empirical model. NANOSCALE 2020; 12:572-583. [PMID: 31803900 DOI: 10.1039/c9nr05946f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The heating ability upon application of an alternating magnetic field of a system of monodisperse and non-interacting superparamagnetic nanoparticles is described by Rosensweig's model within the linear response limits. But in real applications, nanoparticle systems are rarely monodisperse or non-interacting, and predicting their heating ability is challenging, since it requires considering single-particle, inter-particle and collective effects. Herein we give experimental evidence of a collective effect that invalidates the linear response limits in self-assembled anisotropic arrangements. This effect allows tuning Néel relaxation times and, in turn, blocking temperatures, by just varying the alternating magnetic field amplitude. The analysis of the source magnetic and magnetothermal data leads to the development of an empirical model describing the modified Néel relaxation times in terms of characteristic parameters, whose physical interpretation is discussed. As a result, the dependency of Néel relaxation time on the magnetic field amplitude is assigned to a strong interaction energy contribution created locally by the ordered anisotropic assemblies. The reduction of this energy upon application of higher magnetic fields is related to the loss of preferred orientation of the magnetic moment of nanoparticles within assemblies. Remarkably, this energy contribution does not depend on particle volume distribution, so it does not contribute to widening of the energy barrier distribution of the assemblies, avoiding this detrimental effect of magnetic interactions, and contributing to an excellent heating ability. This work thus provides an analytical framework to analyze or predict the magnetic behavior and heating ability of superparamagnetic nanoparticles displaying collective effects.
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Affiliation(s)
- Irene Andreu
- Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC - Universidad de Zaragoza, Campus Río Ebro, María de Luna 3, 50018 Zaragoza, Spain.
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2
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Bian B, Chen G, Zheng Q, Du J, Lu H, Liu JP, Hu Y, Zhang Z. Self-Assembly of CoPt Magnetic Nanoparticle Arrays and its Underlying Forces. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1801184. [PMID: 30058262 DOI: 10.1002/smll.201801184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/01/2018] [Indexed: 06/08/2023]
Abstract
Nanoparticles covered with surfactants are often used to study particle motion patterns and self-assembly processes in solutions. Surfactants have influence on the interparticle interactions and therefore on the particle motion tracks and final patterns. In this study, CoPt nanoparticles are synthesized in aqueous solution without any surfactant. In situ transmission electron microscopy observation is performed to monitor the self-assemble process. Two types of magnetic nanoparticle superlattice arrays are formed: hexagonal equal distance superlattice arrays when particle size is 3 nm, and tight unequal distance superlattice arrays when particle size is 4.5 nm. It is interesting to observe that two small arrays merge into a large one through rotational and translational movements. A Monte Carlo simulation is carried out which successfully restores the whole process. It is identified that the underlying forces are van der Waals and magnetic dipolar interactions. The latter is responsible for orientation of each particle during the whole process. This investigation leads to a better understanding of the formation mechanism of magnetic nanoparticle superlattice arrays.
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Affiliation(s)
- Baoru Bian
- Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Guoxin Chen
- Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Qiang Zheng
- Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Juan Du
- Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Huanming Lu
- Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - J Ping Liu
- Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Yong Hu
- College of Sciences, Northeastern University, Shenyang, 110819, China
| | - Zhidong Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110011, China
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Wen X, Gu L, Bittner AM. Simple Electroless Synthesis of Cobalt Nanoparticle Chains, Oriented by Externally Applied Magnetic Fields. Z PHYS CHEM 2018. [DOI: 10.1515/zpch-2018-1135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The electroless (chemical) deposition of cobalt on palladium-sensitized oxidized silicon wafers produces nanowires and chains made up by nanoparticles. We demonstrate that the application of moderate magnetic fields, provided by permanent magnets, during the growth produces highly oriented cobalt nanowires and nanoparticle chains. By adjusting the magnetic field direction in plane, parallel and crossed cobalt chain patterns are readily accessible. Perpendicular orientation of the field results in rod-like, standing-up chains of nanoparticles. We explain the observed structures with magnetostatic arguments.
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Affiliation(s)
- Xiaogang Wen
- Max Planck Institut für Festkörperforschung , Stuttgart , Germany
| | - Lin Gu
- Max Planck Institut für Metallforschung , Stuttgart , Germany
| | - Alexander M. Bittner
- Max Planck Institut für Festkörperforschung , Stuttgart , Germany
- Ikerbasque, Basque Foundation for Science , 48013 Bilbao , Spain
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4
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The role of dipole interactions in hyperthermia heating colloidal clusters of densely-packed superparamagnetic nanoparticles. Sci Rep 2018; 8:4704. [PMID: 29549359 PMCID: PMC5856762 DOI: 10.1038/s41598-018-23225-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 03/06/2018] [Indexed: 11/09/2022] Open
Abstract
This work aims to investigate the influence of inter-particle dipole interactions on hyperthermia heating colloidal clusters of densely-packed Fe3O4 nanoparticles at low field intensity. Emulsion droplet solvent evaporation method was used to assemble oleic acid modified Fe3O4 particles into compact clusters which were stabilized by surfactant in water. Both experimental and simulation works were conducted to study their heating performance at different cluster's sizes. The dipole interactions improve the heating only when the clusters are small enough to bring an enhancement in clusters' shape anisotropy. The shape anisotropy is reduced at greater clusters' sizes, since the shapes of the clusters become more and more spherical. Consequently, the dipole interactions change to impair the heating efficiency at larger sizes. When the clusters are totally isotropic in shape, the heating efficiency is lower than that of non-interacting particles despite the cluster's size, although the efficiency increases by a little bit at a particular size most likely due to the dipole couplings. In these situations, one has to use particles with higher magnetic anisotropy and/or saturation magnetization to improve the heating.
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Deshmukh R, Mehra A, Thaokar R. Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:494-505. [PMID: 28326240 PMCID: PMC5331312 DOI: 10.3762/bjnano.8.53] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 02/03/2017] [Indexed: 06/06/2023]
Abstract
Aggregation and self-assembly are influenced by molecular interactions. With precise control of molecular interactions, in this study, a wide range of nanostructures ranging from zero-dimensional nanospheres to hierarchical nanoplates and spindles have been successfully synthesized at ambient temperature in aqueous solution. The nanostructures reported here are formed by aggregation of spherical seed particles (monomers) in presence of quaternary ammonium salts. Hydroxide ions and a magnetic moment of the monomers are essential to induce shape anisotropy in the nanostructures. The cobalt nanoplates are studied in detail, and a growth mechanism based on collision, aggregation, and crystal consolidation is proposed based on a electron microscopy studies. The growth mechanism is generalized for rods, spindles, and nearly spherical nanostructures, obtained by varying the cation group in the quaternary ammonium hydroxides. Electron diffraction shows different predominant lattice planes on the edge and on the surface of a nanoplate. The study explains, hereto unaddressed, the temporal evolution of complex magnetic nanostructures. These ferromagnetic nanostructures represent an interesting combination of shape anisotropy and magnetic characteristics.
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Affiliation(s)
- Ruchi Deshmukh
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Anurag Mehra
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Rochish Thaokar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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6
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Powers AS, Liao HG, Raja SN, Bronstein ND, Alivisatos AP, Zheng H. Tracking Nanoparticle Diffusion and Interaction during Self-Assembly in a Liquid Cell. NANO LETTERS 2017; 17:15-20. [PMID: 27995796 DOI: 10.1021/acs.nanolett.6b02972] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nanoparticle self-assembly has been well studied theoretically, but it remains challenging to directly observe and quantify individual nanoparticle interactions. With our custom image analysis method, we track the trajectories of nanoparticle movement with high precision from a stack of relatively noisy images obtained using liquid cell transmission electron microscopy. In a time frame of minutes, Pt-Fe nanoparticles self-assembled into a loosely packed hcp lattice. The energetics and stability of the dynamic assembly were studied quantitatively. From velocity and diffusion measurements, we experimentally determined the magnitude of forces between single particles and the related physical properties. The results illustrate that long-range anisotropic forces drive the formation of chains, which then clump and fold to maximize close range van der Waals interactions.
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Affiliation(s)
| | - Hong-Gang Liao
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Shilpa N Raja
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | | | - A Paul Alivisatos
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Kavli Energy NanoScience Institute , Berkeley, California 94720, United States
| | - Haimei Zheng
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
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7
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Toulemon D, Liu Y, Cattoën X, Leuvrey C, Bégin-Colin S, Pichon BP. Enhanced Collective Magnetic Properties in 2D Monolayers of Iron Oxide Nanoparticles Favored by Local Order and Local 1D Shape Anisotropy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:1621-1628. [PMID: 26807596 DOI: 10.1021/acs.langmuir.5b04145] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Magnetic nanoparticle arrays represent a very attractive research field because their collective properties can be efficiently modulated as a function of the structure of the assembly. Nevertheless, understanding the way dipolar interactions influence the intrinsic magnetic properties of nanoparticles still remains a great challenge. In this study, we report on the preparation of 2D assemblies of iron oxide nanoparticles as monolayers deposited onto substrates. Assemblies have been prepared by using the Langmuir-Blodgett technique and the SAM assisted assembling technique combined to CuAAC "click" reaction. These techniques afford to control the formation of well-defined monolayers of nanoparticles on large areas. The LB technique controls local ordering of nanoparticles, while adjusting the kinetics of CuAAC "click" reaction strongly affects the spatial arrangement of nanoparticles in monolayers. Fast kinetics favor disordered assemblies while slow kinetics favor the formation of chain-like structures. Such anisotropic assemblies are induced by dipolar interactions between nanoparticles as no magnetic field is applied and no solvent evaporation is performed. The collective magnetic properties of monolayers are studied as a function of average interparticle distance, local order and local shape anisotropy. We demonstrate that local control on spatial arrangement of nanoparticles in monolayers significantly strengthens dipolar interactions which enhances collective properties and results in possible super ferromagnetic order.
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Affiliation(s)
- Delphine Toulemon
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS, UMR 7504 UdS/ECPM CNRS) , 23 rue du Loess, BP 43, 67037, Strasbourg, France
| | - Yu Liu
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS, UMR 7504 UdS/ECPM CNRS) , 23 rue du Loess, BP 43, 67037, Strasbourg, France
| | - Xavier Cattoën
- Institut Néel, CNRS and Univ. Grenoble-Alpes, UPR 2940 , 25 rue des Martyrs, 38042 Grenoble, France
| | - Cédric Leuvrey
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS, UMR 7504 UdS/ECPM CNRS) , 23 rue du Loess, BP 43, 67037, Strasbourg, France
| | - Sylvie Bégin-Colin
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS, UMR 7504 UdS/ECPM CNRS) , 23 rue du Loess, BP 43, 67037, Strasbourg, France
| | - Benoit P Pichon
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS, UMR 7504 UdS/ECPM CNRS) , 23 rue du Loess, BP 43, 67037, Strasbourg, France
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8
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Varón M, Beleggia M, Jordanovic J, Schiøtz J, Kasama T, Puntes VF, Frandsen C. Longitudinal domain wall formation in elongated assemblies of ferromagnetic nanoparticles. Sci Rep 2015; 5:14536. [PMID: 26416297 PMCID: PMC4586724 DOI: 10.1038/srep14536] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 08/21/2015] [Indexed: 11/09/2022] Open
Abstract
Through evaporation of dense colloids of ferromagnetic ~13 nm ε-Co particles onto carbon substrates, anisotropic magnetic dipolar interactions can support formation of elongated particle structures with aggregate thicknesses of 100-400 nm and lengths of up to some hundred microns. Lorenz microscopy and electron holography reveal collective magnetic ordering in these structures. However, in contrast to continuous ferromagnetic thin films of comparable dimensions, domain walls appear preferentially as longitudinal, i.e., oriented parallel to the long axis of the nanoparticle assemblies. We explain this unusual domain structure as the result of dipolar interactions and shape anisotropy, in the absence of inter-particle exchange coupling.
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Affiliation(s)
- Miriam Varón
- Technical University of Denmark, Department of Physics, 2800 Kgs. Lyngby, Denmark.,Institut Català de Nanotecnologia, Campus UAB, 08193 Barcelona, Spain
| | - Marco Beleggia
- Technical University of Denmark, Center for Electron Nanoscopy, 2800 Kgs. Lyngby, Denmark.,Helmholtz-Zentrum-Berlin fuer Materialen und Energie, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - Jelena Jordanovic
- Technical University of Denmark, Department of Physics, 2800 Kgs. Lyngby, Denmark
| | - Jakob Schiøtz
- Technical University of Denmark, Department of Physics, 2800 Kgs. Lyngby, Denmark.,Danish National Research Foundation Center for Individual Nanoparticle Functionality, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Takeshi Kasama
- Technical University of Denmark, Center for Electron Nanoscopy, 2800 Kgs. Lyngby, Denmark
| | - Victor F Puntes
- Institut Català de Nanotecnologia, Campus UAB, 08193 Barcelona, Spain.,Vall d'Hebron Institut de Recerca (VHIR), 08035, Barcelona, Spain.,Institut Català de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Cathrine Frandsen
- Technical University of Denmark, Department of Physics, 2800 Kgs. Lyngby, Denmark
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9
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Yang J, Khazen K, Pileni MP. How nanocrystallinity and order define the magnetic properties of ε-Co supracrystals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:295303. [PMID: 24961406 DOI: 10.1088/0953-8984/26/29/295303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Single domain cubic ε-Co nanocrystals are synthesized via a high-temperature thermal decomposition of cobalt carbonyl in the presence of oleic acid and trioctylphosphane oxide (TOPO). The ε-Co nanocrystals are characterized by a low size distribution (σ < 7%) and the average diameter is tuned from 7 nm to 9 nm by tailoring the molar ratio of the surfactants oleic acid and TOPO. Moreover, we have demonstrated the self-assembly of ε-Co nanocrystals in highly ordered three-dimensional (3D) face-centered cubic (fcc) structures called supracrystals. The layer-by-layer organization of these building blocks is achieved through solvent evaporation. Simultaneously, we produce. with the same ε-Co nanocrystals, disordered (amorphous) films. We demonstrate the presence of large interparticle magnetic interactions in the supracrystals by comparing their magnetic properties with the diluted samples. Then, by a detailed comparison of their collective magnetic properties with partially disordered films, the significant differences due to the change in anisotropy and distribution of dipolar interaction energies in the two systems are presented. This is attributed to the orientational and spatial ordering of single domain ε-Co nanocrystals markedly changing between ordered and disordered assemblies. The thermal evolution of the magnetization in ZFC/FC procedure presents three characteristic temperatures representing the blocking, the irreversibility and the maximum of Zeeman coupling temperatures. They are all affected by the presence of the order in supracrystals and they present different evolution trends as a function of nanoparticles size. While the variations of reduced remanent magnetizations in both condensed series are in good agreement with the previous theoretical calculations, the coercive fields present opposite evolutions.
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Affiliation(s)
- Jianhui Yang
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, F-75005, Paris, France
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10
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Morgan DG, Boris BS, Kuchkina NV, Yuzik-Klimova EY, Sorokina SA, Stein BD, Svergun DI, Spilotros A, Kostopoulou A, Lappas A, Shifrina ZB, Bronstein LM. Multicore iron oxide mesocrystals stabilized by a poly(phenylenepyridyl) dendron and dendrimer: role of the dendron/dendrimer self-assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:8543-8550. [PMID: 24963746 DOI: 10.1021/la502409r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report the formation of multicore iron oxide mesocrystals using the thermal decomposition of iron acetyl acetonate in the presence of the multifunctional and rigid poly(phenylenepyridyl) dendron and dendrimer. We thoroughly analyze the influence of capping molecules of two different architectures and demonstrate for the first time that dendron/dendrimer self-assembly leads to multicore morphologies. Single-crystalline ordering in multicore NPs leads to cooperative magnetic behavior: mesocrystals exhibit ambient blocking temperatures, allowing subtle control over magnetic properties using a minor temperature change.
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Affiliation(s)
- David Gene Morgan
- Department of Chemistry and ‡Department of Biology, Indiana University , Bloomington, Indiana 47405, United States
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11
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Lee B, Yeon KM, Shim J, Kim SR, Lee CH, Lee J, Kim J. Effective antifouling using quorum-quenching acylase stabilized in magnetically-separable mesoporous silica. Biomacromolecules 2014; 15:1153-9. [PMID: 24601563 DOI: 10.1021/bm401595q] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Highly effective antifouling was achieved by immobilizing and stabilizing an acylase, disrupting bacterial cell-to-cell communication, in the form of cross-linked enzymes in magnetically separable mesoporous silica. This so-called "quorum-quenching" acylase (AC) was adsorbed into spherical mesoporous silica (S-MPS) with magnetic nanoparticles (Mag-S-MPS), and further cross-linked for the preparation of nanoscale enzyme reactors of AC in Mag-S-MPS (NER-AC/Mag-S-MPS). NER-AC effectively stabilized the AC activity under rigorous shaking at 200 rpm for 1 month, while free and adsorbed AC lost more than 90% of their initial activities in the same condition within 1 and 10 days, respectively. When applied to the membrane filtration for advanced water treatment, NER-AC efficiently alleviated the biofilm maturation of Pseudomonas aeruginosa PAO1 on the membrane surface, thereby enhancing the filtration performance by preventing membrane fouling. Highly stable and magnetically separable NER-AC, as an effective and sustainable antifouling material, has a great potential to be used in the membrane filtration for water reclamation.
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Affiliation(s)
- Byoungsoo Lee
- Department of Chemical and Biological Engineering, Korea University , Seoul 136-701, Korea
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12
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Varón M, Beleggia M, Kasama T, Harrison RJ, Dunin-Borkowski RE, Puntes VF, Frandsen C. Dipolar magnetism in ordered and disordered low-dimensional nanoparticle assemblies. Sci Rep 2013; 3:1234. [PMID: 23390584 PMCID: PMC3565170 DOI: 10.1038/srep01234] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 01/18/2013] [Indexed: 11/14/2022] Open
Abstract
Magnetostatic (dipolar) interactions between nanoparticles promise to open new ways to design nanocrystalline magnetic materials and devices if the collective magnetic properties can be controlled at the nanoparticle level. Magnetic dipolar interactions are sufficiently strong to sustain magnetic order at ambient temperature in assemblies of closely-spaced nanoparticles with magnetic moments of ≥ 100 μB. Here we use electron holography with sub-particle resolution to reveal the correlation between particle arrangement and magnetic order in self-assembled 1D and quasi-2D arrangements of 15 nm cobalt nanoparticles. In the initial states, we observe dipolar ferromagnetism, antiferromagnetism and local flux closure, depending on the particle arrangement. Surprisingly, after magnetic saturation, measurements and numerical simulations show that overall ferromagnetic order exists in the present nanoparticle assemblies even when their arrangement is completely disordered. Such direct quantification of the correlation between topological and magnetic order is essential for the technological exploitation of magnetic quasi-2D nanoparticle assemblies.
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Affiliation(s)
- M Varón
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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13
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Bellido E, Domingo N, Ojea-Jiménez I, Ruiz-Molina D. Structuration and integration of magnetic nanoparticles on surfaces and devices. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:1465-1491. [PMID: 22467627 DOI: 10.1002/smll.201101456] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 11/07/2011] [Indexed: 05/31/2023]
Abstract
Different experimental approaches used for structuration of magnetic nanoparticles on surfaces are reviewed. Nanoparticles tend to organize on surfaces through self-assembly mechanisms controlled by non-covalent interactions which are modulated by their shape, size and morphology as well as by other external parameters such as the nature of the solvent or the capping layer. Further control on the structuration can be achieved by the use of external magnetic fields or other structuring techniques, mainly lithographic or atomic force microscopy (AFM)-based techniques. Moreover, results can be improved by chemical functionalization or the use of biological templates. Chemical functionalization of the nanoparticles and/or the surface ensures a proper stability as well as control of the formation of a (sub)monolayer. On the other hand, the use of biological templates facilitates the structuration of several families of nanoparticles, which otherwise may be difficult to form, simply by establishing the experimental conditions required for the structuration of the organic capsule. All these experimental efforts are directed ultimately to the integration of magnetic nanoparticles in sensors which constitute the future generation of hybrid magnetic devices.
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Affiliation(s)
- Elena Bellido
- Centro de Investigación en Nanociencia y Nanotecnología, (Esfera UAB. Campus UAB, Cerdanyola del Vallès, Spain
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14
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"Magnetic force microscopy and energy loss imaging of superparamagnetic iron oxide nanoparticles". Sci Rep 2011; 1:202. [PMID: 22355717 PMCID: PMC3244111 DOI: 10.1038/srep00202] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 12/07/2011] [Indexed: 12/02/2022] Open
Abstract
We present quantitative, high spatially resolved magnetic force microscopy imaging of samples based on 11 nm diameter superparamagnetic iron oxide nanoparticles in air at room temperature. By a proper combination of the cantilever resonance frequency shift, oscillation amplitude and phase lag we obtain the tip-sample interaction maps in terms of force gradient and energy dissipation. These physical quantities are evaluated in the frame of a tip-particle magnetic interaction model also including the tip oscillation amplitude. Magnetic nanoparticles are characterized both in bare form, after deposition on a flat substrate, and as magnetically assembled fillers in a polymer matrix, in the form of nanowires. The latter approach makes it possible to reveal the magnetic texture in a composite sample independently of the surface topography.
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15
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Kim MI, Shim J, Li T, Lee J, Park HG. Fabrication of Nanoporous Nanocomposites Entrapping Fe
3
O
4
Magnetic Nanoparticles and Oxidases for Colorimetric Biosensing. Chemistry 2011; 17:10700-7. [PMID: 21837719 DOI: 10.1002/chem.201101191] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Indexed: 11/11/2022]
Affiliation(s)
- Moon Il Kim
- Department of Chemical and Biomolecular Engineering (BK21 Program), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305‐701 (Korea), Fax: (+82) 42‐350‐3910
| | - Jongmin Shim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790‐784 (Korea)
| | - Taihua Li
- Department of Chemical and Biomolecular Engineering (BK21 Program), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305‐701 (Korea), Fax: (+82) 42‐350‐3910
| | - Jinwoo Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790‐784 (Korea)
| | - Hyun Gyu Park
- Department of Chemical and Biomolecular Engineering (BK21 Program), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305‐701 (Korea), Fax: (+82) 42‐350‐3910
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16
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Pichon BP, Pauly M, Marie P, Leuvrey C, Begin-Colin S. Tunable magnetic properties of nanoparticle two-dimensional assemblies addressed by mixed self-assembled monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:6235-6243. [PMID: 21495667 DOI: 10.1021/la105052z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Assemblies of magnetic nanoparticles (NPs) are intensively studied due to their high potential applications in spintronic, magnetic and magneto-electronic. The fine control over NP density, interdistance, and spatial arrangement onto substrates is of key importance to govern the magnetic properties through dipolar interactions. In this study, magnetic iron oxide NPs have been assembled on surfaces patterned with self-assembled monolayers (SAMs) of mixed organic molecules. The modification of the molar ratio between coadsorbed 11-mercaptoundecanoic acid (MUA) and mercaptododecane (MDD) on gold substrates is shown to control the size of NPs domains and thus to modulate the characteristic magnetic properties of the assemblies. Moreover, NPs can be used to indirectly probe the structure of SAMs in domains at the nanometer scale.
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Affiliation(s)
- Benoit P Pichon
- Institut de Physique et de Chimie des Matériaux de Strasbourg, 23 rue du Loess-BP 43, 67034 Strasbourg Cedex 2, France.
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