ELECTRORHEOLOGICAL AND DIELECTRIC PROPERTIES OF UREA/SIO2 NANOCOMPOSITE SUSPENSIONS MODIFIED BY N, N-DIMETHYLFORMAMIDE

In this study, electrorheological (ER) behaviour of silica nanocomposite suspensions treated with urea and N , N – dimethylformamide (DMF) in DC electric field has been investigated. While the ER effect of the neat silica itself was very low, the modification of silica nanoparticles improved compatibility of the solid and liquid phase and increased considerably ER activity of the system. In contrast to maximum possible concentration about 5 wt.% of neat silica due to particle aggregation 20 wt.% suspension of treated particles with low field-off viscosity could be prepared. The dielectric measurements showed that with increasing amount of urea deposited on the silica particles both the difference between the limit values of the relative permittivities and the relaxation frequency increased. This indicates a great influence of both particle polarizability and the rate of rearrangement of the ER structure in the electric field on the ER intensity. After DMF addition the changes in dielectric properties reflected the higher ER activity. At higher particle loading (25 wt.%) mutual particle interaction increased and field-off viscosity steeply rose. The comparison of the behavior of 20 and 25 wt.% suspensions of modified particles showed that even if high yield stress at higher particle content under electric field application sets in, its relative increase indicating the ER efficiency due to high field-off value may be much lower than at lower suspension loading.

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Передача крутящего момента проводящей частице с использованием силы Лоренца

Физика и техника полупроводников ◽

10.21883/ftp.2022.01.51815.9703 ◽

2022 ◽

Vol 56 (1) ◽

pp. 76

Author(s):

А.И. Грачев

Keyword(s):

Dipole Moment ◽

Electric Field ◽

Electric Dipole Moment ◽

Electric Dipole ◽

Field Application ◽

Conductive Particle ◽

Particle Rotation ◽

Dc Electric Field ◽

First Time ◽

Cylindrical Particles

In the paper the concept of conductive particle rotation in DC electric field with including the Lorentz force providing generation of electric dipole moment of the particle is for the first time discussed. Some models of the torque transfer to spherical and cylindrical particles based on of the Hall effect at usual geometry and with additional electric field application and also in the case of implementation of the photoelectromagnetic effect are presented.

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Dielectric Properties and Phase Transition of [110]-Oriented 0.68PMN-0.32PT Single Crystals Induced by Temperature and DC Electric Field

Key Engineering Materials - High-Performance Ceramics IV ◽

10.4028/0-87849-410-3.42 ◽

2007 ◽

pp. 42-45

Author(s):

Zhen Rong Li ◽

Jun Jie Qian ◽

Guo Qiang Zhang ◽

Zeng Zhe Xi ◽

Zhuo Xu ◽

...

Keyword(s):

Phase Transition ◽

Dielectric Properties ◽

Electric Field ◽

Single Crystals ◽

Dc Electric Field

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Origin of P-E Hysteresis Offsets in Compositionally Graded Ba(1-x)SrxTiO3 Thick Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.55-57.15 ◽

2008 ◽

Vol 55-57 ◽

pp. 15-22 ◽

Cited By ~ 2

Author(s):

Jeremie Barrel ◽

Eugene Stytsenko ◽

Massimo Viviani ◽

Kenneth MacKenzie

Keyword(s):

Electric Field ◽

Thick Films ◽

Schottky Contacts ◽

Deposition Technique ◽

Alternating Electric Field ◽

Polarization Axis ◽

Dc Electric Field ◽

The Difference

Compositionally graded Ba(1-x)SrxTiO3 thick films were fabricated by the airflow deposition technique. Films displayed hysteresis translation along the polarization axis when driven by an alternating electric field. The trend of the hysteresis shift as a function of temperature is similar to the difference of DC currents measured when a positive and negative DC electric field is applied. The study suggests that the origin of this phenomenon lies in an asymmetry of the film conductance due to the presence of asymmetric Schottky contacts at the BaTiO3/Ag and Ag/Ba0.xSr1-0.xTiO3 interfaces.

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Dielectric Properties of Dielectrophoretically Aligned ZnO-PDMS Composites

Volume 1: Multifunctional Materials; Mechanics and Behavior of Active Materials; Integrated System Design and Implementation; Structural Health Monitoring ◽

10.1115/smasis2016-9128 ◽

2016 ◽

Cited By ~ 1

Author(s):

Md Abdulla Al Masud ◽

Zoubeida Ounaies

Keyword(s):

Dielectric Properties ◽

Dielectric Permittivity ◽

Electric Field ◽

Mechanical Analysis ◽

High Yield ◽

Chemical Route ◽

Random Composites ◽

Pdms Elastomer ◽

Random Dispersion ◽

Zno Rods

ZnO based polymer composite materials are of great interest because of their excellent electrical, optical, semiconductor and biocompatible properties. In this study, we synthesize anisotropic composites of aligned ZnO rods in polydimethylsiloxane (PDMS) elastomer and study their dielectric properties as a function of applied electric field and frequency. Submicron ZnO rods are synthesized using an inexpensive, high yield chemical route. Washed and purified ZnO rods are then aligned in uncured PDMS at different electric field and frequency. We find that under electric field, ZnO rotates with their long axis in the direction of the electric field and before coalescing form chains in the silicone elastomer. From the optical microscopy images and in situ dielectric measurements, the best alignment parameters are found at 4 kV/mm and 10 kHz. These conditions are then selected to prepare aligned ZnO-PDMS composites. Complete curing of composites is confirmed using dynamic mechanical analysis (DMA). Our results show that aligned ZnO in uncured PDMS exhibit higher dielectric permittivity compared to random dispersion with the same composition. For the cured ZnO-PDMS composites, dielectric permittivity increases by 80% compared to random composites.

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Modification of the Dielectric Properties of TGS Crystal Grown Under the Influence of DC Electric Field with Different Strengths

Ferroelectrics ◽

10.1080/00150190390239369 ◽

2003 ◽

Vol 295 (1) ◽

pp. 97-112 ◽

Cited By ~ 1

Author(s):

G. Arunmozhi ◽

E. De Matos Gomes ◽

J. L. Ribeiro

Keyword(s):

Dielectric Properties ◽

Electric Field ◽

Dc Electric Field

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Iterative Dipole Moment Method for the Dielectrophoretic Particle-Particle Interaction in a DC Electric Field

Journal of Nanotechnology ◽

10.1155/2018/3539075 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Qing Zhang ◽

Kai Zhang

Keyword(s):

Dipole Moment ◽

Electric Field ◽

Moment Method ◽

Particle Interaction ◽

Particle Interactions ◽

Electric Force ◽

Microfluidic Systems ◽

Initial Particle ◽

Connection Line ◽

Dc Electric Field

Electric force is the most popular technique for bioparticle transportation and manipulation in microfluidic systems. In this paper, the iterative dipole moment (IDM) method was used to calculate the dielectrophoretic (DEP) forces of particle-particle interactions in a two-dimensional DC electric field, and the Lagrangian method was used to solve the transportation of particles. It was found that the DEP properties and whether the connection line between initial positions of particles perpendicular or parallel to the electric field greatly affect the chain patterns. In addition, the dependence of the DEP particle interaction upon the particle diameters, initial particle positions, and the DEP properties have been studied in detail. The conclusions are advantageous in elelctrokinetic microfluidic systems where it may be desirable to control, manipulate, and assemble bioparticles.

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In-situ application of dc electric field on ferroelectric substances in an electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109501 ◽

1978 ◽

Vol 36 (1) ◽

pp. 472-473

Author(s):

N. Yamamoto ◽

K. Yagi ◽

G. Honjo

Keyword(s):

Electron Microscope ◽

Electric Field ◽

Field Application ◽

Cooling Stage ◽

Specimen Holder ◽

Present Technique ◽

Dc Electric Field ◽

Very High ◽

Dynamic Phenomena

A technique of in-situ application of a dc electric field on a specimen in an electron microscope has been developed to directly observe dynamic phenomena due to the electric field. In the present technique a thickness of a specimen is so thin that a very high electric field can be applied; a few volt of the potential difference across the specimen of the order of 1000 Å thick gives a field as high as 105 V/cm. An additional field application electrode was incorporated not only in a specimen heating holder but also in a liquid helium cooling stage which had been constructed in our 1aboratory. Thus, the experiments could be performed in a wide temperature range of 13-1000K. Fig.la schematically depicts a specimen holder installed in the cooling stage. The detailed arrangement around a specimen is shown in Fig.1b. An electric potential is applied between electrodes of thin A1 films vacuum deposited on the both faces of the specimen.

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