scholarly journals Magnetic field-induced self-assembly of iron oxide nanocubes

2015 ◽  
Vol 181 ◽  
pp. 403-421 ◽  
Author(s):  
Gurvinder Singh ◽  
Henry Chan ◽  
T. Udayabhaskararao ◽  
Elijah Gelman ◽  
Davide Peddis ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Self Assembly ◽  
Inorganic Nanoparticles ◽  
The Self ◽  
One Dimensional ◽  
Experimental Parameters ◽  
First Time ◽  
The Magnetic Field

Self-assembly of inorganic nanoparticles has been studied extensively for particles having different sizes and compositions. However, relatively little attention has been devoted to how the shape and surface chemistry of magnetic nanoparticles affects their self-assembly properties. Here, we undertook a combined experiment–theory study aimed at better understanding of the self-assembly of cubic magnetite (Fe3O4) particles. We demonstrated that, depending on the experimental parameters, such as the direction of the magnetic field and nanoparticle density, a variety of superstructures can be obtained, including one-dimensional filaments and helices, as well as C-shaped assemblies described here for the first time. Furthermore, we functionalized the surfaces of the magnetic nanocubes with light-sensitive ligands. Using these modified nanoparticles, we were able to achieve orthogonal control of self-assembly using a magnetic field and light.

BIREFRINGENCE AND MAGNETO-OPTICAL PROPERTIES IN OLEIC ACID COATED Fe3O4 NANOPARTICLES: APPLICATION FOR OPTICAL SWITCH

2011 ◽  
Vol 10 (03) ◽  
pp. 515-520 ◽  
Author(s):  
SI-HUA XIA ◽  
JUN WANG ◽  
ZHANG-XIAN LU ◽  
FEIYAN ZHANG
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Oleic Acid ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Optical Switch ◽  
Colloidal Suspension ◽  
Experimental Parameters ◽  
Nanoparticle Chains ◽  
The Magnetic Field

We report magneto-optical properties in a kerosene colloidal suspension of oleic acid coated Fe3O4 nanoparticles (~14 nm). The magnetic colloids (fluids) show birefringence under a magnetic field. Systematical studies of the on–off switch times upon application of the on–off magnetic field with varied experimental parameters indicate that the switch response time depends strongly on the strength of the magnetic field and the concentration of the magnetic nanoparticles in the fluid. The data can be explained in terms of the formation of magnetic nanoparticle chains under a magnetic field. The important magneto-optical properties of the magnetic fluids allow us to design a tunable optical switch.

scholarly journals Self-assembly mechanism of Ni nanowires prepared with an external magnetic field

2015 ◽  
Vol 6 ◽  
pp. 2123-2128 ◽  
Author(s):  
Xiaoyu Li ◽  
Hu Wang ◽  
Kenan Xie ◽  
Qin Long ◽  
Xuefei Lai ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Self Assembly ◽  
Chemical Reduction ◽  
Reaction System ◽  
The Self ◽  
Nickel Nanowires ◽  
Assembly Mechanism ◽  
Nickel Particles ◽  
First Time

Nickel nanowires with a mean diameter of about 95 nm and lengths of up to 26 μm were prepared by a chemical reduction method in aqueous solution under an external magnetic field. The self-assembly mechanism was investigated in detail. The results indicate that the self-assembly process of Ni nanowires consists of three stages: nucleation and growth, ordered alignment and self-assembly, and deposition on the surface and gaps between the nickel particles. The self-assembly phenomenon occurs only when nickel particles grow to a size of about 60 nm in the reaction system. This critical size, which is proposed for the first time, is very important to comprehend the self-assembly mechanism of Ni nanowires prepared with an external magnetic field.

scholarly journals New Insights on the Self-Assembly of Bio-sourced Block Copolymer MH-b-PS in Aqueous Solutions: Nanocorals, Cubosomes & Nanocubes

2021 ◽  
Author(s):  
Yomen Atassi ◽  
Redouane Borsali
Keyword(s):  
Aqueous Solution ◽  
Block Copolymer ◽  
Aqueous Solutions ◽  
Self Assembly ◽  
Room Temperature ◽  
Linear Structure ◽  
The Self ◽  
Fine Tuning ◽  
Experimental Parameters ◽  
First Time

Polymer self-assembly in solution still constitutes a simple methodology for the preparation of elegant yet sophisticated nanomaterials. This work aims at presenting how the fine tuning of the experimental parameters of the nanoprecipitation process can lead to a variety of novel morphologies ranging from nanocorals through cubosomes to nanocubes. A carbohydrate dibloc copolymer with a simple and linear structure MH1.2k-b-PS2.3 has been used as a model to illustrate the formation of these new self-assemblies. This is the first time that nanocube morphology has been generated using this type of bio-sourced co-polymer in aqueous solution and at room temperature.

scholarly journals The on-axis magnetic well and Mercier's criterion for arbitrary stellarator geometries

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
P. Kim ◽  
R. Jorge ◽  
W. Dorland
Keyword(s):  
Magnetic Field ◽  
Original Work ◽  
Three Dimensional ◽  
Radial Distance ◽  
Analytical Form ◽  
One Dimensional ◽  
Modern Notation ◽  
Magnetic Well ◽  
First Time ◽  
Dimensional Integral

A simplified analytical form of the on-axis magnetic well and Mercier's criterion for interchange instabilities for arbitrary three-dimensional magnetic field geometries is derived. For this purpose, a near-axis expansion based on a direct coordinate approach is used by expressing the toroidal magnetic flux in terms of powers of the radial distance to the magnetic axis. For the first time, the magnetic well and Mercier's criterion are then written as a one-dimensional integral with respect to the axis arclength. When compared with the original work of Mercier, the derivation here is presented using modern notation and in a more streamlined manner that highlights essential steps. Finally, these expressions are verified numerically using several quasisymmetric and non-quasisymmetric stellarator configurations including Wendelstein 7-X.

scholarly journals Ferro-self-assembly: magnetic and electrochemical adaptation of a multiresponsive zwitterionic metalloamphiphile showing a shape-hysteresis effect

2021 ◽  
Vol 12 (1) ◽  
pp. 270-281
Author(s):  
Stefan Bitter ◽  
Moritz Schlötter ◽  
Markus Schilling ◽  
Marina Krumova ◽  
Sebastian Polarz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Real Time ◽  
Self Assembly ◽  
Hysteresis Effect ◽  
The Self ◽  
Self Organization ◽  
Stimuli Responsive ◽  
Optical Birefringence

The self-organization properties of a stimuli responsive amphiphile can be altered by subjecting the paramagnetic oxidized form to a magnetic field of 0.8 T and monitored in real time by coupling optical birefringence with dynamic light scattering.

A dissipative particle dynamics simulation study on phase diagrams for the self-assembly of amphiphilic hyperbranched multiarm copolymers in various solvents

Soft Matter ◽  
2017 ◽  
Vol 13 (36) ◽  
pp. 6178-6188 ◽  
Author(s):  
Haina Tan ◽  
Chunyang Yu ◽  
Zhongyuan Lu ◽  
Yongfeng Zhou ◽  
Deyue Yan
Keyword(s):  
Phase Diagrams ◽  
Simulation Study ◽  
Self Assembly ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
The Self ◽  
Dynamics Simulation ◽  
Dynamics Simulations ◽  
First Time ◽  
Dissipative Particle Dynamics Simulation

This work discloses for the first time the self-assembly phase diagrams of amphiphilic hyperbranched multiarm copolymers in various solvents by dissipative particle dynamics simulations.

scholarly journals In Vivo Study on Magnetomotive Ultrasound Imaging in the Framework of Nanoparticle based Magnetic Drug Targeting

2020 ◽  
Vol 6 (3) ◽  
pp. 543-546
Author(s):  
Michael Fink ◽  
Stefan J. Rupitsch ◽  
Helmut Ermert ◽  
Stefan Lyer
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Drug Targeting ◽  
Imaging Technique ◽  
Small Animal ◽  
Magnetic Drug Targeting ◽  
Oxide Nanoparticles ◽  
Medical Procedures ◽  
First Time

AbstractVarious medical procedures make use of magnetic nanoparticles, such as Magnetic Drug Targeting (MDT), which boosts the demand for imaging modalities that are capable of in vivo visualizing this kind of particles. Magnetomotive Ultrasound is an imaging technique that can detect tissue, which is perfused by magnetic nanoparticles. In this contribution, we investigate the suitability of Magnetomotive Ultrasound to serve as a monitoring system during MDT. With the conducted measurements, it was possible for the first time to observe in vivo the accumulation of iron-oxide nanoparticles during a Magnetic Drug Targeting cancer treatment applied to a small animal (rabbit).

A smart sensing Zn (Ⅱ) coordination polymer based on a new viologen ligand exhibiting photochromic and thermochromic and multiple solid detection properties

2021 ◽  
Author(s):  
Heyi Zhang ◽  
Fangyuan He ◽  
Xiaonan Li ◽  
Zhi-Hui Wang ◽  
Hong Zhang
Keyword(s):  
Electron Transfer ◽  
Coordination Polymer ◽  
Self Assembly ◽  
Chain Structure ◽  
The Self ◽  
Dimensional Chain ◽  
One Dimensional ◽  
Smart Sensing

Through the self-assembly of 1,1'-bis(3-cyanobenzyl)-[4,4'-bipyridine] dichloride ligand, m-H2BDC and Zn(NO3)2·6H2O, a novel one-dimensional chain structure multifunctional coordination polymer was successfully synthesized. Due to electron transfer during irradiation and heating to...

In Vitro Evaluation of Capturing and Dissolving the Clot by Magnetic Nanoparticles Carrying a Thrombolytic Agents Instead of Temporary Inferior Vena Cava (IVC) Filter

2020 ◽  
Vol 16 (11) ◽  
pp. 1623-1632
Author(s):  
Abbas Moghanizadeh ◽  
Fakhreddin Ashrafizadeh ◽  
Jaleh Varshousaz ◽  
Mahshid Kharaziha
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Vena Cava ◽  
Simple Method ◽  
Thrombolytic Agents ◽  
Blood Clots ◽  
Life Threatening ◽  
The Magnetic Field ◽  
Different Levels

This study aims to evaluate the efficiency of a novel in vitro technique in clot capturing and dissolving them by applying magnetic force on magnetic nanoparticles (MNP) carrying thrombolytic agents. It is a quick and simple method to protect patients from a life-threatening pulmonary embolism in an emergency to provide time for the medical team. To analyze the in vitro efficiency of nano-magnetic capturing and dissolving of clots (NCDC), different levels of process parameter including strength magnetic field (0.1, 0.2 and 0.3 T) and fluid flow rate (2.5, 5 and 7 l/min) are exposed to different blood clots sizes from 5 × 10 to 20 × 10 mm2 (length × diameter), in an in vitro flow model. The results show that by increasing the parameters to their maximum values, it is possible to immobilize 100% of the clots and dissolve around 61.4% of clots weight. In addition, the clot-dissolving is directly proportional to the magnetic field strength. NCDC is an efficient technique in immobilizing and dissolving the clots and its efficiency depends on process parameters especially the magnetic field.

scholarly journals The influence of resistivity gradients on shock conditions for a Petschek reconnection geometry

2016 ◽  
Vol 34 (4) ◽  
pp. 421-425
Author(s):  
Christian Nabert ◽  
Karl-Heinz Glassmeier
Keyword(s):  
Magnetic Field ◽  
Necessary Conditions ◽  
The Other ◽  
Diffusion Region ◽  
Two Dimensional ◽  
Characteristic Velocity ◽  
Magnetohydrodynamic Equations ◽  
One Dimensional ◽  
The Magnetic Field ◽  
Alfven Velocity

Abstract. Shock waves can strongly influence magnetic reconnection as seen by the slow shocks attached to the diffusion region in Petschek reconnection. We derive necessary conditions for such shocks in a nonuniform resistive magnetohydrodynamic plasma and discuss them with respect to the slow shocks in Petschek reconnection. Expressions for the spatial variation of the velocity and the magnetic field are derived by rearranging terms of the resistive magnetohydrodynamic equations without solving them. These expressions contain removable singularities if the flow velocity of the plasma equals a certain characteristic velocity depending on the other flow quantities. Such a singularity can be related to the strong spatial variations across a shock. In contrast to the analysis of Rankine–Hugoniot relations, the investigation of these singularities allows us to take the finite resistivity into account. Starting from considering perpendicular shocks in a simplified one-dimensional geometry to introduce the approach, shock conditions for a more general two-dimensional situation are derived. Then the latter relations are limited to an incompressible plasma to consider the subcritical slow shocks of Petschek reconnection. A gradient of the resistivity significantly modifies the characteristic velocity of wave propagation. The corresponding relations show that a gradient of the resistivity can lower the characteristic Alfvén velocity to an effective Alfvén velocity. This can strongly impact the conditions for shocks in a Petschek reconnection geometry.

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