POLAR MOLECULE TYPE ELECTRORHEOLOGICAL FLUIDS

2007 ◽  
Vol 21 (28n29) ◽  
pp. 4798-4805 ◽  
Author(s):  
KUNQUAN LU ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
GANG SUN ◽  
WEIJIA WEN ◽  
...  
Keyword(s):  
Electric Field ◽  
High Performance ◽  
Polar Molecule ◽  
Electrorheological Fluids ◽  
High Yield ◽  
Polar Molecules ◽  
Dynamic Shear ◽  
Effective Factors ◽  
Er Fluids ◽  
Molecule Type

The static and dynamic shear stress of newly developed electrorheological (ER) fluids can reach more than 100 kPa and over 60 kPa at 3 kV/mm, respectively. The high yield stress of those ER fluids and its near linear dependence on the electric field are different from the conventional ER fluids and can not be explained with traditional dielectric theory. Experiment demonstrates that the polar molecules adsorbed on the particles play crucial role in those ER fluids, which can be named as polar molecule type electrorheological (PM-ER) fluids. To explain PM-ER effect a model is proposed based on the interaction of polar molecule-charge in between the particles, where the local electric field is much higher than the external one and can cause the polar molecules aligning. The main effective factors for achieving high-performance PM-ER fluids are discussed.

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.

POLAR MOLECULE TYPE ELECTRORHEOLOGICAL FLUIDS

2007 ◽  
Author(s):  
KUNQUAN LU ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
GONG SUN ◽  
WEIJIA WEN ◽  
...  
Keyword(s):  
Polar Molecule ◽  
Electrorheological Fluids ◽  
Molecule Type

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.

scholarly journals Strong Electrorheological Performance of Smart Fluids Based on TiO2 Particles at Relatively Low Electric Field

2021 ◽  
Vol 8 ◽  
Author(s):  
Yuchuan Cheng ◽  
Zihui Zhao ◽  
Hui Wang ◽  
Letian Hua ◽  
Aihua Sun ◽  
...  
Keyword(s):  
Electric Field ◽  
Yield Stress ◽  
Sol Gel ◽  
Interfacial Polarization ◽  
High Yield ◽  
Characteristic Structure ◽  
High Yield Stress ◽  
Large Yield ◽  
Er Fluids ◽  
Er Fluid

Electrorheological (ER) fluids are a type of smart material with adjustable rheological properties. Generally, the high yield stress (>100 kPa) requires high electric field strength (>4 kV/mm). Herein, the TiO2 nanoparticles were synthesized via the sol–gel method. Interestingly, the ER fluid-based TiO2 nanoparticles give superior high yield stress of 144.0 kPa at only 2.5 kV/mm. By exploring the characteristic structure and dielectric property of TiO2 nanoparticles and ER fluid, the surface polar molecules on samples were assumed to play a crucial role for their giant electrorheological effect, while interfacial polarization was assumed to be dominated and induces large yield stress at the low electric field, which gives the advantage in low power consumption, sufficient shear stress, low leaking current, and security.

ER-FLUID RHEOLOGICAL PROPERTIES IN TERMS OF THE MULTIPARTICLE MODEL OF A COMPOSITE

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2676-2682
Author(s):  
YU. G. YANOVSKY ◽  
V. E. ZGAEVSKII ◽  
Z. P. SHULMAN ◽  
E. V. KOROBKO
Keyword(s):  
Electric Field ◽  
Rheological Properties ◽  
Three Dimensional ◽  
Microscopic Theory ◽  
Electrorheological Fluids ◽  
Mathematical Apparatus ◽  
Couple Interaction ◽  
Er Fluids ◽  
Er Fluid ◽  
Electrorheological Properties

The three-dimensional multi-particle well-ordered model could be considered as an analogy to a crystal body. We use this model for describing rheological properties of concentrated electrorheological fluids (ER fluids). According to this model, the particles of the suspension take their places at sites of a grid with specified type of symmetry and then an electric field is applied to the fluid. Taking into account hydrodynamic couple interaction of particles and forces of electrostatic interaction of particles polarized under the action of an external electric field and employing the mathematical apparatus of the microscopic theory of crystals, we construct the basic relationships for describing viscoelastic electrorheological properties of ER fluids.

Polar-Molecule-Dominated Electrorheological Fluids Featuring High Yield Stresses

2009 ◽  
Vol 21 (45) ◽  
pp. 4631-4635 ◽  
Author(s):  
Rong Shen ◽  
Xuezhao Wang ◽  
Yang Lu ◽  
De Wang ◽  
Gang Sun ◽  
...  
Keyword(s):  
Polar Molecule ◽  
Electrorheological Fluids ◽  
High Yield

Investigation of Thermal Conductivity of Alumina/Silicone Oil Electrorheological Fluids

2010 ◽  
Vol 129-131 ◽  
pp. 421-425 ◽  
Author(s):  
Yi Chun Wang ◽  
Xiao Xia Sun ◽  
Xiao Rong Tang ◽  
Fa Cheng Wang
Keyword(s):  
Thermal Conductivity ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Silicone Oil ◽  
Conductivity Measurement ◽  
Electrorheological Fluids ◽  
High Voltage Power Supply ◽  
Heating Device ◽  
Er Fluids

Electrorheological (ER) fluids are new materials with good properties such as dielectric constant, dielectric loss or conductivity, which display remarkable rheological behavior, being able to convert rapidly and repeatedly from a liquid to solid when an electric field is applied or removed. In this study, suspensions of alumina (A) were prepared in silicone oil (SO). The effects of electric field strength and temperature of the suspensions on thermal conductivity were determined. Thermal conductivity measurement in different conditions was carried out via experimental instrument with high-voltage power supply and water heating device to investigate the effects of electric field strength and temperature on ER performance and thermal conductivity. The results show that the thermal conductivity is in accordance with ER properties enhanced by increasing the field strength and decreasing the temperature.

scholarly journals Electrorheological Fluids of GO/Graphene-Based Nanoplates

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 311
Author(s):  
Yudong Wang ◽  
Jinhua Yuan ◽  
Xiaopeng Zhao ◽  
Jianbo Yin
Keyword(s):  
Electric Fields ◽  
Smart Materials ◽  
High Performance ◽  
Short Circuit ◽  
Dielectric Spectrum ◽  
Electrorheological Fluids ◽  
Dispersed Phase ◽  
External Electric Fields ◽  
Anisotropic Morphology ◽  
Er Fluids

Due to their unique anisotropic morphology and properties, graphene-based materials have received extensive attention in the field of smart materials. Recent studies show that graphene-based materials have potential application as a dispersed phase to develop high-performance electrorheological (ER) fluids, a kind of smart suspension whose viscosity and viscoelastic properties can be adjusted by external electric fields. However, pure graphene is not suitable for use as the dispersed phase of ER fluids due to the electric short circuit caused by its high electrical conductivity under electric fields. However, graphene oxide (GO) and graphene-based composites are suitable for use as the dispersed phase of ER fluids and show significantly enhanced property. In this review, we look critically at the latest developments of ER fluids based on GO and graphene-based composites, including their preparation, electrically tunable ER property, and dispersed stability. The mechanism behind enhanced ER property is discussed according to dielectric spectrum analysis. Finally, we also propose the remaining challenges and possible developments for the future outlook in this field.

POLAR-MOLECULE-DOMINATED ELECTRORHEOLOGICAL (PM-ER) FLUIDS: THE PROPERTIES AND EVALUATIONS

2011 ◽  
Vol 25 (07) ◽  
pp. 957-962 ◽  
Author(s):  
KUNQUAN LU ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
DE WANG ◽  
GANG SUN
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Yield Stress ◽  
Linear Dependence ◽  
Polar Molecule ◽  
High Yield ◽  
Electric Response ◽  
New Type ◽  
Er Fluids ◽  
Er Fluid

In recent years, a new type ER fluids named as polar-molecule-dominated electrorheological (PM-ER) fluids have been developed, of which the yield stress can reach more than 100 kPa and behaves a linear dependence on the electric field. A brief description on the composition and synthesizing method for the materials is given. The main merits of PM-ER fluid are as follows: high yield stress, the shear stress increasing with shear rate up to more than 103 s -1, low current density, rapid electric response and anti-sedimentation. Some perspectives on PM-ER fluid and its applications are presented.

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