Sedimentation equilibrium of magnetic nanoparticles with strong dipole-dipole interactions

2017 ◽  
Vol 95 (3) ◽  
Author(s):  
Andrey A. Kuznetsov ◽  
Alexander F. Pshenichnikov
Keyword(s):  
Magnetic Nanoparticles ◽  
Sedimentation Equilibrium ◽  
Dipole Interactions ◽  
Strong Dipole

scholarly journals Tacticity Effect on Mesogen-Free Liquid Crystalline Self-assembly Induced by Strong Dipole–Dipole Interactions

2019 ◽  
Vol 52 (10) ◽  
pp. 3601-3611 ◽  
Author(s):  
Man-Hin Kwok ◽  
Bryan T. Seymour ◽  
Ruipeng Li ◽  
Morton H. Litt ◽  
Bin Zhao ◽  
...  
Keyword(s):  
Self Assembly ◽  
Liquid Crystalline ◽  
Dipole Interactions ◽  
Strong Dipole

Cyano-substitution on the end-capping group: facile access toward asymmetrical squaraine showing strong dipole–dipole interactions as a high performance small molecular organic solar cells material

2015 ◽  
Vol 3 (34) ◽  
pp. 17704-17712 ◽  
Author(s):  
Daobin Yang ◽  
Yan Jiao ◽  
Lin Yang ◽  
Yao Chen ◽  
Satoshi Mizoi ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
High Performance ◽  
Dipole Interactions ◽  
End Capping ◽  
Strong Dipole

Cyano-substituted asymmetrical squaraines for organic solar cells with a high PCE was synthesized.

scholarly journals Direct mapping of local director field of nematic liquid crystals at the nanoscale

2015 ◽  
Vol 112 (50) ◽  
pp. 15291-15296 ◽  
Author(s):  
Yu Xia ◽  
Francesca Serra ◽  
Randall D. Kamien ◽  
Kathleen J. Stebe ◽  
Shu Yang
Keyword(s):  
Liquid Crystals ◽  
Soft Matter ◽  
Real Space ◽  
Colloidal Systems ◽  
Director Field ◽  
Silica Surfaces ◽  
Dipole Interactions ◽  
Molecular Ordering ◽  
New Type ◽  
Strong Dipole

Liquid crystals (LCs), owing to their anisotropy in molecular ordering, are of wide interest in both the display industry and soft matter as a route to more sophisticated optical objects, to direct phase separation, and to facilitate colloidal assemblies. However, it remains challenging to directly probe the molecular-scale organization of nonglassy nematic LC molecules without altering the LC directors. We design and synthesize a new type of nematic liquid crystal monomer (LCM) system with strong dipole–dipole interactions, resulting in a stable nematic phase and strong homeotropic anchoring on silica surfaces. Upon photopolymerization, the director field can be faithfully “locked,” allowing for direct visualization of the LC director field and defect structures by scanning electron microscopy (SEM) in real space with 100-nm resolution. Using this technique, we study the nematic textures in more complex LC/colloidal systems and calculate the extrapolation length of the LCM.

Cation-anion pairs of niobium clusters of the type [Nb6Cl12(RCN)6][Nb6Cl18] (R=Et, nPr, iPr) with nitrile ligands RCN forming stabilizing inter-ionic contacts

2020 ◽  
Vol 75 (1-2) ◽  
pp. 173-181
Author(s):  
Eric Sperlich ◽  
Martin Köckerling
Keyword(s):  
Cluster Compounds ◽  
Cluster Ions ◽  
Cluster Anions ◽  
Dipole Interactions ◽  
Average Oxidation State ◽  
Metal Atoms ◽  
Cluster Cation ◽  
Acid Anhydrides ◽  
Strong Dipole ◽  
Positively Charged

AbstractThree new niobium cluster compounds with edge bridged, octahedral hexanuclear metal cores have been synthesised. They consist of cluster pairs with [Nb6Cl12(RCN)6]2+ cations, [Nb6Cl18]2− anions, and co-crystallised nitrile molecules, with R = C2H5 (propionitrile), nC3H7 (butyronitrile), iC3H7 (isobutyronitrile). The synthesis is based on the dehydration of [Nb6Cl14(H2O)4] · 4(H2O) with carboxylic acid anhydrides in the presences of an excess of the respective nitrile. An interesting aspect of these compounds is that the metal atoms of the cluster cation have an average oxidation state different from that of the cluster anion, the former being oxidized losing two electrons. In crystals of all three compounds layers of cluster cations are separated by layers of cluster anions. Perpendicular to these layers of the same cluster types, every cation is surrounded by four anions and vice versa. Between the cations and anions short distances are found between the halogenido ligands and the positively charged C atoms of the nitrile ligands (N–C · · · Cl angles of ~90°). These contacts indicate relatively strong dipole-dipole interactions, which presumably contribute to the arrangement of the cluster ions in the crystals.

scholarly journals Magnetic interactions between nanoparticles

2010 ◽  
Vol 1 ◽  
pp. 182-190 ◽  
Author(s):  
Steen Mørup ◽  
Mikkel Fougt Hansen ◽  
Cathrine Frandsen
Keyword(s):  
Magnetic Nanoparticles ◽  
Spin Glasses ◽  
Mean Field ◽  
Exchange Interactions ◽  
Magnetic Interactions ◽  
Collective State ◽  
Particle Interactions ◽  
Mean Field Model ◽  
Strong Suppression ◽  
Dipole Interactions

We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions.

scholarly journals Entanglement via rotational blockade of MgF molecules in a magic potential

2021 ◽  
Author(s):  
Eunmi Chae
Keyword(s):  
Optical Tweezers ◽  
Polarization Angle ◽  
Dipole Interactions ◽  
Strong Dipole

Rotations of MgF molecules can be entangled via strong dipole–dipole interactions when trapped in optical tweezers with a magic polarization angle.

scholarly journals Effect of Central Longitudinal Dipole Interactions on Chiral Liquid-Crystal Phases

2018 ◽  
Vol 19 (9) ◽  
pp. 2715 ◽  
Author(s):  
Takuma Nozawa ◽  
Paul Brumby ◽  
Kenji Yasuoka
Keyword(s):  
Liquid Crystals ◽  
Phase Behavior ◽  
Coarse Grained ◽  
Systematic Analysis ◽  
Dipole Interactions ◽  
Liquid Phases ◽  
Systematic Understanding ◽  
Chiral Systems ◽  
Chiral Liquid Crystals ◽  
Strong Dipole

Monte Carlo simulations of chiral liquid-crystals, represented by a simple coarse-grained chiral Gay–Berne model, were performed to investigate the effect of central longitudinal dipole interactions on phase behavior. A systematic analysis of the structural properties and phase behavior of both achiral and chiral systems, with dipole interactions, reveals differing effects; strong dipole interactions enhance the formation of layered structures; however, chiral interactions may prevent the formation of such phases under certain conditions. We also observed a short-ranged smectic structure within the cholesteric phases with strong dipole interactions. This constitutes possible evidence of presmectic ordering and/or the existence of chiral line liquid phases, which have previously been observed in X-ray experiments to occur between the smectic twisted grain boundary and cholesteric phases. These results provide a systematic understanding of how the phase behavior of chiral liquid-crystals changes when alterations are made to the strength of dipole interactions.

scholarly journals Magnetization Reversal and Specific Loss Power of Magnetic Nanoparticles in Cellular Environment Evaluated by AC Hysteresis Measurement

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Satoshi Ota ◽  
Tsutomu Yamada ◽  
Yasushi Takemura
Keyword(s):  
Magnetic Nanoparticles ◽  
Theoretical Model ◽  
Single Cell ◽  
Magnetization Reversal ◽  
Heat Dissipation ◽  
Magnetic Moments ◽  
Hysteresis Loops ◽  
Dipole Interactions ◽  
Fixed Sample ◽  
Cellular Environment

The effect of intracellular hyperthermia induced by magnetic nanoparticles (MNPs) has been evaluated using a theoretical model. In this study, magnetization reversal of MNPs in the cellular environment under an AC magnetic field was evaluated on the basis of measured AC hysteresis loops. The specific and intrinsic loss powers—SLP and ILP—were also estimated from the area of AC hysteresis loops. The measured samples were a liquid sample dispersed in water, a fixed sample mixed with an epoxy bond, and a cellular sample. In the cellular environment, the rotations of particles and magnetic moments were inhibited by particle-cell and dipole-dipole interactions, respectively. The heat dissipation of the MNPs in the cellular environment was lower than that of the liquid and fixed samples. Moreover, the SLP in a single cell was estimated. The temperature increase of a single cell was calculated on the basis of the conventional theoretical model and the SLP measured in a single cell.

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