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.

Infinite solitons in ferromagnetic materials with an internal magnetic field

2021 ◽  
pp. 2150413
Author(s):  
Hamdy I. Abdel-Gawad
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
External Field ◽  
Model Equation ◽  
Graphical Representation ◽  
Magnetic Moments ◽  
Soliton Solutions ◽  
Internal Magnetic Field ◽  
Multiple Soliton Solutions ◽  
The Magnetic Field

The ferromagnetism induced by an external magnetic field (EMF), in (3+1) dimensions, is governed by Kraenkel–Manna–Merle system (KMMS). A (1+1) dimension model equation was derived in the literature. The magnetic moments are parallel to the magnetic field in ferromagnetism as they are aligning in the same direction of the external field. Here, it is shown that the KMMS supports the presence of internal magnetic field. This may be argued to medium characteristics. The objective of this work is to mind multiple soliton solutions, which are obtained via the generalized together with extended unified methods. Graphical representation of the results are carried. They describe infinite soliton shapes, which arise from the multiple variation of the arbitrary functions in the solutions. It is, also, shown that internal magnetic field decays, asymptotically, to zero with time.

scholarly journals Simultaneous polydirectional transport of colloidal bipeds

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Mahla Mirzaee-Kakhki ◽  
Adrian Ernst ◽  
Daniel de las Heras ◽  
Maciej Urbaniak ◽  
Feliks Stobiecki ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
External Field ◽  
Colloidal Particles ◽  
Addition Reaction ◽  
Lab On A Chip ◽  
Magnetic Pattern ◽  
Colloidal Spheres ◽  
Colloidal Science ◽  
Colloidal Rods

Abstract Detailed control over the motion of colloidal particles is relevant in many applications in colloidal science such as lab-on-a-chip devices. Here, we use an external magnetic field to assemble paramagnetic colloidal spheres into colloidal rods of several lengths. The rods reside above a square magnetic pattern and are transported via modulation of the direction of the external magnetic field. The rods behave like bipeds walking above the pattern. Depending on their length, the bipeds perform topologically distinct classes of protected walks. We design parallel polydirectional modulation loops of the external field that command up to six classes of bipeds to walk on distinct predesigned paths. Using such loops, we induce the collision of reactant bipeds, their polymerization addition reaction to larger bipeds, the separation of product bipeds from the educts, the sorting of different product bipeds, and also the parallel writing of a word consisting of several letters. Our ideas and methodology might be transferred to other systems for which topological protection is at work.

Nanocomposites and macroscopic materials: assembly of chemically modified graphene sheets

2012 ◽  
Vol 41 (18) ◽  
pp. 6160 ◽  
Author(s):  
Dongqing Wu ◽  
Fan Zhang ◽  
Haiwei Liang ◽  
Xinliang Feng
Keyword(s):  
Graphene Sheets ◽  
Chemically Modified ◽  
Modified Graphene

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.

QUANTUM QUASI-SOLITONS IN THE TWO-DIMENSIONAL FERROMAGNETIC LATTICE WITH AN EXTERNAL FIELD

2013 ◽  
Vol 27 (09) ◽  
pp. 1350058 ◽  
Author(s):  
DE-JUN LI ◽  
BING TANG ◽  
KE HU ◽  
YI TANG
Keyword(s):  
Magnetic Field ◽  
Quantum Theory ◽  
External Magnetic Field ◽  
External Field ◽  
Multiple Scale ◽  
Two Dimensional ◽  
Scale Method ◽  
Nonlinear Excitations ◽  
Localized Mode ◽  
Intrinsic Localized Mode

Based on the quantum theory and a simplified version of the multiple-scale method, the nonlinear excitations in a two-dimensional ferromagnetic lattice with an external magnetic field are analytically investigated. The standard two-dimensional nonlinear Schrödinger equation is obtained. Results show that the quantum quasi-soliton can exist in the two-dimensional ferromagnetic lattice. In addition, when the group velocity is equal to zero, at the boundary of the Brillouin zone, the quantum quasi-soliton becomes the quantum intrinsic localized mode.

EQUILIBRIUM PATTERNS OF CHAIN CLUSTERS COMPOSED OF FERROMAGNETIC PARTICLES IN AN EXTERNAL MAGNETIC FIELD

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2352-2356 ◽  
Author(s):  
TOMOFUMI UKAI ◽  
TORU MAEKAWA ◽  
HISAO MORIMOTO
Keyword(s):  
Magnetic Field ◽  
Monte Carlo ◽  
Dipole Moment ◽  
External Magnetic Field ◽  
Thermal Energy ◽  
Colloidal System ◽  
Control Parameters ◽  
Ordered Structures ◽  
Pattern Formations ◽  
Ferromagnetic Particles

We carry out Monte Carlo simulations of a ferromagnetic colloidal system, which is subjected to an external magnetic field, to investigate the structures formed by chain clusters. The control parameters are the ratio of the dipole moment energy to thermal energy, λ, and the ratio of the interactive energy between the dipole and the external magnetic field to thermal energy, ξ. We investigate the effect of the system height on the pattern formations for λ=18 and ξ=30, ∞. Note that the system becomes paramagnetic when ξ=∞. We find that as the system height increases, chains coagulate to form fat clusters and spatially ordered structures are created when ξ=30, whereas chains form thin meandering walls when ξ=∞.

Preparation of Graphene/Fe3O4/Polypyrrole Nanocomposite and its Adsorption for Cr(VI) Ions

2014 ◽  
Vol 905 ◽  
pp. 61-64
Author(s):  
Wei Yao ◽  
Yun Lu
Keyword(s):  
Magnetic Field ◽  
Heavy Metal ◽  
External Magnetic Field ◽  
Magnetic Nanocomposites ◽  
Graphene Sheets ◽  
The Novel ◽  
Efficient Removal ◽  
Good Consistency ◽  
Adsorption Desorption ◽  
Adsorption Capability

The novel magnetic nanocomposites have been prepared by simultaneous forming of Fe3O4 nanospheres and graphene sheets in an anchoring mode and polymerizing of pyrrole on the Fe3O4 surface. TEM, XRD and XPS were used to characterize the as-prepared products. Nanocomposites exhibit excellent adsorption capability of 348.4 mg g-1 for heavy metal Cr (VI) ions, and moreover, are stable, separable easily under external magnetic field and recyclable, retaining about 83.1% of the removal efficiency after four adsorption-desorption cycles. The adsorption isotherm has been studied and shows a good consistency with the Langmuir mode. The nanocomposites could be a good candidate for efficient removal of Cr (VI) from the wastewater.

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>

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