THE CONDUCTIVITY AND TEMPERATURE DEPENDENCE OF BATIO3 COATED- PAN BASED ELECTRORHEOLOGICAL FLUIDS

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1423-1429 ◽  
Author(s):  
J. H. WEI ◽  
J. SHI ◽  
Z. Y. LIU ◽  
J. G. GUAN ◽  
R. Z. YUAN
Keyword(s):  
Shear Stress ◽  
Barium Titanate ◽  
Silicone Oil ◽  
Sol Gel ◽  
Temperature Stability ◽  
Electrorheological Fluids ◽  
Environment Temperature ◽  
Er Fluids ◽  
Favorable Temperature ◽  
Gel Processing

Coated-PAn particles consisting of polyaniline(PAn) core and barium titanate ( BaTiO 3) shell were synthesized by modified sol-gel processing. The shear stress and current density of the suspensions of Coated-PAn particles and pure PAn particles in silicone oil with a 20vol% were investigated at different conductivity and environment temperature. The dielectric and the conductance behavior of coated PAn particles as a function of temperature we also investigated. The results showed that the ER effect of BaTiO 3 coated PAn particles was far stronger than that of pure polyaniline synthesized by the same method. Meanwhile, the BaTiO 3 coated-PAn particles also showed favorable temperature stability and low current loss at the high electric field, which is rather important for the ER fluids application.

Dependence of the shear stress on particle properties in electrorheological fluids

2001 ◽  
Vol 15 (06n07) ◽  
pp. 938-946 ◽  
Author(s):  
Kunquan Lu ◽  
Yucheng Lan ◽  
Shouqiang Men ◽  
Xiaoyu Xu ◽  
Zhao Xianpeng ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Shear Stress ◽  
Silicone Oil ◽  
Theoretical Calculations ◽  
Ferroelectric Material ◽  
Electrorheological Fluids ◽  
Particle Properties ◽  
Er Fluids ◽  
Er Fluid ◽  
Curie Temperature Tc

By measuring the shear stress of a ferroelectric particle/silicone oil ER fluid varying with the temperature across Tc, the dependence of ER effect on permittivity mismatch is quantitatively obtained. The dielectric property of ferroelectric material behaves a dramatic change at Curie temperature (Tc) either in the dielectric constant and the conductivity. TGS and KNO 3 ferroelectric particles are chosen for studying the dielectric constant and conductivity dependence of the shear stress in ER fluids respectively. The measured results are more reliable, because the conditions, such as size, shape, composition of particles, especially chemical nature of particles and interface property between particles and liquid, all are same. The available theoretical calculations can not well fit our measured results. In order to consider the properties of whole suspensions, the orientation of the particles with spontaneous polarization under an electric field was studied in advance.

ELECTRORHEOLOGICAL EFFECT OF CONDUCTIVE POLYMERS DISPERSED IN LIQUID CRYSTALLINE MATRIX

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1135-1141 ◽  
Author(s):  
MONIKA CISZEWSKA ◽  
JANUSZ PLOCHARSKI
Keyword(s):  
Liquid Crystalline ◽  
Silicone Oil ◽  
Crystalline Polymer ◽  
Electrorheological Fluids ◽  
Flow Curves ◽  
Homogeneous Solutions ◽  
Electrorheological Effect ◽  
Active Liquid ◽  
Er Fluids ◽  
Crystalline Matrix

Hybrid electrorheological fluids comprising powdered conjugated polymers dispersed in solutions of a liquid crystalline polymer were prepared and studied. FeCl 3 doped poly(p-phenylene) and pyrolised polyacrylonitrile were chosen as the dispersed phase and poly(n-hexyl isocyanate) dissolved in xylene was used as the active liquid matrix. All the component materials were extensively characterized by various methods. Flow curves of the hybrid ER fluids were recorded under electric field and compared with analogous curves obtained for dispersions of the powders in silicone oil and with homogeneous solutions of the LC polymer in xylene. A very significant enhancement of the ER effect in the studied hybrid fluids was observed.

Review of the Electrorheological (Er) Effect of Polyurethane-based Er Fluids

2008 ◽  
Vol 18 (2) ◽  
pp. 23956-1-23956-8 ◽  
Author(s):  
S. Schneider ◽  
S. Eibl
Keyword(s):  
Silicone Oil ◽  
Molecular Size ◽  
Electrorheological Fluids ◽  
Chemical Analyses ◽  
Temperature Dependent ◽  
Polarization Model ◽  
Basic Principles ◽  
Dependent Behavior ◽  
Er Fluids ◽  
Temperature Dependent Behavior

Abstract Electrorheological fluids (ERF) change viscosity when an electric field is applied. A special type of ERF consists of polyurethane particles which are doped with Li+ and /or Zn2+ cations and suspended in silicone oil. This article gives an overview of the temperature dependent behavior of the ER effect for these fluids and describes the basic principles how this is explained. Chemical analyses provide information as a basis for a polarization model in several dimensions down to molecular size.

THE ELECTRORHEOLOGICAL FLUIDS WITH HIGH SHEAR STRESS

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1065-1070 ◽  
Author(s):  
KUNQUAN LU ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
GANG SUN ◽  
WEIJIA WEN
Keyword(s):  
Shear Stress ◽  
Electric Field ◽  
Yield Stress ◽  
High Performance ◽  
Electrorheological Fluids ◽  
Stress Effect ◽  
High Shear ◽  
High Shear Stress ◽  
Effective Factors ◽  
Er Fluids

A series of high performance ER fluids newly manufactured in our laboratory are presented. The yield stress of those ER fluids can reach several tens of kPa, 100 kPa and even 200 kPa, respectively. For understanding the high shear stress effect a model is proposed base on the electric field induced molecular bounding effect. The main effective factors in fabricating the high performance ER are discussed.

ELECTROSTATIC INTERACTIONS FOR PARTICLE ARRAYS IN ELECTRORHEOLOGICAL FLUIDS II: MEASUREMENTS

1994 ◽  
Vol 08 (20n21) ◽  
pp. 2895-2902 ◽  
Author(s):  
YING CHEN ◽  
H. CONRAD
Keyword(s):  
Shear Modulus ◽  
Electric Field ◽  
Shear Strain ◽  
Enhancement Factor ◽  
Shear Force ◽  
Electrostatic Interactions ◽  
Silicone Oil ◽  
Electrorheological Fluids ◽  
Proportionality Constant ◽  
Er Fluids

The force required to shear one-, two- and three-chain clusters of 230 µm dia. glass beads in silicone oil was measured. In each case the shear force was proportional to the shear strain, the proportionality constant increasing with electric field and number n of chains in the cluster. The derived shear modulus G also increased with n. An extrapolation of the present results suggests that a cluster of 4–5 chains would give the stress enhancement factor of 10–20 observed for real ER fluids.

EFFECT OF RARE EARTH SUBSTITUTION ON ELECTRORHEOLOGICAL PROPERTIES OF TiO2

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2371-2377 ◽  
Author(s):  
X. P. ZHAO ◽  
J. B. YIN ◽  
L. Q. XIANG ◽  
Q. ZHAO
Keyword(s):  
Shear Stress ◽  
Rare Earth ◽  
Silicone Oil ◽  
Anatase Phase ◽  
New Class ◽  
Dc Electric Field ◽  
Er Fluids ◽  
Er Fluid ◽  
Electrorheological Properties ◽  
Rare Earth Substitution

This paper describes a new class of water-free electrorheological (ER) fluids based on nonaqueous doped TiO 2 with rare earth (RE) in silicone oil. The thermal character and crystal structure of these materials are investigated with DSC, TG and XRD. The doped TiO 2 crystals possess anatase phase and their lattice spacing varies significantly with the content of rare earth. The rheological measurements show that the doped TiO 2 ER fluid exhibits an obviously higher shear stress than that of pure TiO 2 ER fluid under dc electric field. Especially, substitution with 10mol% cerium or 8mol% lanthanum for Ti can obtain a relatively high shear stress. On the basis of dielectric and conduction measurements, we preliminarily discuss the influence of the doping of rare earth on ER effects of TiO 2.

Crystallization of barium titanate thin films synthesized via sol-gel processing

1995 ◽  
Vol 53 ◽  
pp. 258-259
Author(s):  
M. C. Gust ◽  
N. D. Evans ◽  
M. L. Mecartney
Keyword(s):  
Thin Films ◽  
Barium Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Independent Films ◽  
X Ray ◽  
Fine Grained ◽  
Diffraction Patterns ◽  
Gel Processing ◽  
Alkoxide Precursors

Sol-gel processing of oxide thin films offers the potential to generate different microstructures by varying process parameters such as water of hydrolysis, chemical precursor, or substrate. For this work, barium titanate (BaTiO3) thin films were prepared by the sol-gel method in order to try and generate different microstructures for dielectric measurements. However, for BaTiOs prepared using alkoxide precursors, the final microstructures of the films were found to be almost process independent. Films using different precursors, different substrates, and different amounts of water of hydrolysis all showed similar TEM microstructures. All the films after final heat treatment were polycrystalline, nanoporous, and randomly oriented BaTiO3; they were also fine-grained, with an average uniform grain size of 25-50 nm (Fig. 1). This fine-grained microstructure has also been observed in other studies of sol-gel derived BaTiO3 thin films. In addition to BaTiO3, electron diffraction patterns showed the presence of trace amounts of rutile TiO2 that were not observed by x-ray diffraction (XRD).

Sound Transmission Loss in Electrorheological Fluids Under DC Voltage

2000 ◽  
Author(s):  
Marek L. Szary ◽  
Maciej Noras
Keyword(s):  
Shear Stress ◽  
Sound Pressure ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Electrorheological Fluids ◽  
Sound Transmission Loss ◽  
Dc Voltage ◽  
College Of Engineering ◽  
Er Fluids ◽  
Er Fluid

Abstract Extensive investigations of sound transmission loss (STL) in electrorheological (ER) fluids were conducted in the Acoustics Laboratory in the College of Engineering, Southern Illinois University Carbondale. The STL was investigated for different kinds of ER suspensions in frequency ranges from 100 Hz to 2kHz. Applied DC voltage to the different electrodes allowed normal and shear stress to develop in the ER fluid respectively. The electric field density was variable. Sound transmission loss was obtained by measurement of the sound pressure level in front of and behind the sample. Under both normal and shear stress in ER fluid, STL decreases with increasing stress. Those properties of ER fluids can be useful in noise and vibration control applications.

Modeling and Analysis of the Electrorheological Fluids (Suspension Flow) with Aligned-Structure Reformation

2012 ◽  
Vol 77 ◽  
pp. 103-107
Author(s):  
Young Wook Seo ◽  
Hyoung Jin Choi ◽  
Yong Sok Seo
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Shear Rate ◽  
Field Strength ◽  
Electrorheological Fluids ◽  
Suspension Flow ◽  
Polarization Model ◽  
Modeling And Analysis ◽  
Proposed Model ◽  
Er Fluids

A new rheological model is applied to the analysis of the behavior of electrorheological (ER) fluids. A comparison of the model’s predictions with experimental data shows that the proposed model correctly predicts the shear stress behavior both quantitatively and qualitatively. The shear stress data for the aligned particles’ structure reformation can be fitted as a function of shear rate with the new model. The yield stress was found to be almost linearly dependent on the field strength, different from the predictions of the polarization model.

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