Study of Self-Assembly of Octahedral Magnetite under an External Magnetic Field

2009 ◽  
Vol 113 (40) ◽  
pp. 17301-17305 ◽  
Author(s):  
Haiping Qi ◽  
Qianwang Chen ◽  
Mingsheng Wang ◽  
Minhua Wen ◽  
Jie Xiong
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Self Assembly

Exploration of the Structures of the Magnetically Induced Self-Assembly Photonic Crystals in a Solidified Polymer Matrix

2013 ◽  
Vol 634-638 ◽  
pp. 2324-2331
Author(s):  
Hai Bo Hu ◽  
Qian Wang Chen ◽  
Ran Li ◽  
Xiang Kai Kong ◽  
Jian Chen
Keyword(s):  
Magnetic Field ◽  
Photonic Crystal ◽  
External Magnetic Field ◽  
Crystal Structures ◽  
Polymer Matrix ◽  
Self Assembly ◽  
Large Scale ◽  
Solid Polymer ◽  
One Dimension ◽  
Polyacrylamide Hydrogel

The carbon-encapsulated superparamagnetic colloidal nanoparticles (SCNps) were rigidized into soft solids by embedding the SCNps into polyacrylamide hydrogel matrixes under the induction of an external magnetic field. Stabilized by the balance of attractive (magnetic) and repulsive (electrostatic) forces, the SCNps form one-dimension photonic crystal structures along the direction of the external magnetic field and further the structures are frozen into the solidified polymer matrix. The polymer matrix embedded one-dimension photonic crystal structures can strongly diffract visible light and present brilliant color in the light. This novel and soft solid polymer matrix that could be shaped and sliced not only paves a new avenue for develop novel magnetic-responsive photonic crystal materials and devices, but also provides a method to observe the magnetic-induced self-assembly structures of the SCNps in media such as polyacrylamide hydrogel matrixs as a result of the ordered structures frozen into the polyacrylamide hydrogel matrixs. So we can reveal the relationship between their structure and color, and furthermore permit a systematic exploration on magnetically induced self-assembling dynamics, colloidal crystallography which have important significance in the large-scale industrial production in the future.

scholarly journals Ferro-Self-Assembly: Magnetic and Electrochemical Adaptation of a Multiresponsive Zwitterionic Metalloamphiphile Showing a Shape-Hysteresis Effect

2020 ◽  
Author(s):  
Stefan Bitter ◽  
Moritz Schlötter ◽  
Markus Schilling ◽  
Rainer Winter ◽  
Sebastian Polarz
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Self Assembly ◽  
Hysteresis Effect ◽  
The Self ◽  
Stimuli Responsive ◽  
Tubular Aggregates ◽  
Optical Birefringence ◽  
Sufficient Concentration

We report on a novel multi-stimuli-responsive amphiphile, 1-(<i>Z</i>)-heptenyl-1’-dimethylammonium-methyl-(3-sulfopropyl)ferrocene<b> </b>(<b>6</b>), whose self-assembly properties can be altered by three different stimuli, namely: (i) the addition of external salts which serve to unfold the sultone headgroup, thus triggering self-assembly of <b>6</b> into vesicles; (ii) oxidation to <b>6<sup>+</sup></b>, which changes the lipophilic ferrocene to a hydrophilic ferrocenium entity, thereby broadening the size-distribution of the aggregates; and (iii) exposition of <b>6<sup>+</sup> </b>to an external magnetic field of 0.8 T. Under thease conditions and at sufficient concentration, <b>6</b><sup><b>+</b> </sup>forms large, tubular aggregates with lengths of up to 15 µm, which persist for over 5 min after the field is switched off again. <b>6<sup>+</sup></b> is thus the first amphiphile to exhibit a shape-hysteresis effect. The self-assembly/disassembly processes and their dynamics were studied live and in situ by optical birefringence measurements coupled to light scattering. <br>

scholarly journals Self‐Assembly Anisotropic Magnetic Nanowire Films Induced by External Magnetic Field

ChemistryOpen ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 588-592 ◽  
Author(s):  
Muhammad Hassan ◽  
Hui‐Juan Zhan ◽  
Jin‐Long Wang ◽  
Jian‐Wei Liu ◽  
Jia‐Fu Chen
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Self Assembly ◽  
Magnetic Nanowire

scholarly journals Self-assembly of chemically modified graphene sheets in an external magnetic field

RSC Advances ◽  
2019 ◽  
Vol 9 (34) ◽  
pp. 19457-19464
Author(s):  
Mingqiong Tong ◽  
Jianda Cao ◽  
Xiaoping Chen ◽  
Huanxia Zhang ◽  
Wen Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
External Field ◽  
Self Assembly ◽  
Graphene Sheets ◽  
Ordered Structures ◽  
Chemically Modified ◽  
Modified Graphene

The rapid developments of effective self-assembly technologies indicated that ordered structures of GO could be produced using external field inducement.

scholarly journals Self-assembly of smallest magnetic particles

2015 ◽  
Vol 112 (47) ◽  
pp. 14484-14489 ◽  
Author(s):  
Sara Mehdizadeh Taheri ◽  
Maria Michaelis ◽  
Thomas Friedrich ◽  
Beate Förster ◽  
Markus Drechsler ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Data Storage ◽  
Self Assembly ◽  
Magnetic Particles ◽  
Dipole Interaction ◽  
The Self ◽  
Magnetic Structures ◽  
Medical Technologies ◽  
1D Chains

The assembly of tiny magnetic particles in external magnetic fields is important for many applications ranging from data storage to medical technologies. The development of ever smaller magnetic structures is restricted by a size limit, where the particles are just barely magnetic. For such particles we report the discovery of a kind of solution assembly hitherto unobserved, to our knowledge. The fact that the assembly occurs in solution is very relevant for applications, where magnetic nanoparticles are either solution-processed or are used in liquid biological environments. Induced by an external magnetic field, nanocubes spontaneously assemble into 1D chains, 2D monolayer sheets, and large 3D cuboids with almost perfect internal ordering. The self-assembly of the nanocubes can be elucidated considering the dipole–dipole interaction of small superparamagnetic particles. Complex 3D geometrical arrangements of the nanodipoles are obtained under the assumption that the orientation of magnetization is freely adjustable within the superlattice and tends to minimize the binding energy. On that basis the magnetic moment of the cuboids can be explained.

THE ASSEMBLY OF CHAIN-LIKE Ni ARRAYS UNDER MAGNETIC FIELD AND ITS ENHANCED PROPERTIES

2010 ◽  
Vol 09 (05) ◽  
pp. 543-547 ◽  
Author(s):  
JUN WANG ◽  
SHIHE CAO ◽  
SIHUA XIA ◽  
NING GAN
Keyword(s):  
Magnetic Field ◽  
Electron Microscope ◽  
External Magnetic Field ◽  
Self Assembly ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Vertical Arrays ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Facile Hydrothermal Process

Chain-like nickel arrays assembled from magnetic Ni spheres were successfully prepared through a facile hydrothermal process at 200°C under a 0.25 T external magnetic field. The external magnetic field is strongly believed to be the driving force of the self-assembly. The sample was highly crystalline as confirmed by the X-ray diffraction (XRD) patterns. The scanning electron microscope (SEM) and transmission electron microscope (TEM) images show that all Ni spheres are closely interconnected to form chains, with ~ 950 nm in diameter and ~ 1 cm in length, which arrange into vertical arrays on the silicon substrate. The coercivity and remnant magnetization ratio of the sample, 670 Oe and 0.612, respectively, are substantially higher than for the sample prepared without an applied external magnetic field (68 Oe and 0.336). Such enhancements can be attributed to their novel superstructure, shape anisotropy, reduced demagnetization factor, etc. This process can be used to fabricate large arrays of uniform chains of magnetic materials and modulate their magnetic properties.

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.

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