Electroviscoelastic Properties in ER Gel of Disperse System under DC Electric Field

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2433-2439 ◽  
Author(s):  
R. HANAOKA ◽  
S. TAKATA ◽  
H. FUJITA ◽  
T. FUKAMI ◽  
K. SAKURAI ◽  
...  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Disperse System ◽  
Fine Particles ◽  
Silicone Oil ◽  
Dynamic Properties ◽  
Low Frequencies ◽  
Hydrosilylation Reaction ◽  
Microscopical Method ◽  
Dc Electric Field

The silicone oil-based electrorheological (ER) gel containing the non-aqueous fine particles was newly created in the present study. After these particles were dispersed at 30wt.% in the dimethylsilicone oil, the ER gel was produced by the hydrosilylation reaction in the mixture of the modified silicone oil. The reaction could considerably be promoted by heating at 90°C. The behavior of particles in the ER gel was observed by a microscopical method. When an electric field was applied to the ER gel, the gap between the electrodes was bridged by the chains of particles arranged in the direction of the electric field. The dynamic properties of the ER gel were also examined under the applied dc electric field up to 2kV/mm using the oscillating rheometer with the low frequencies of 1Hz or less. Consequently, it is shown that the electroviscoelastic effect of the gel can be controlled by the electric field strength.

Breakups of an encapsulated surfactant-laden aqueous droplet under a DC electric field

Soft Matter ◽  
2019 ◽  
Vol 15 (43) ◽  
pp. 8905-8911 ◽  
Author(s):  
Muhammad Salman Abbasi ◽  
Ryungeun Song ◽  
Jinkee Lee
Keyword(s):  
Electric Field ◽  
Castor Oil ◽  
Silicone Oil ◽  
Double Emulsion ◽  
Emulsion Droplet ◽  
Dc Electric Field ◽  
Aqueous Droplet

We study the breakups of a surfactant-laden aqueous/silicone oil/castor oil double emulsion droplet under an electric field.

Measurement of Interaction Forces at Small Distance under Electric Field in a Smectite Dispersed Silicone Oil Based ER Fluid

2001 ◽  
Vol 15 (06n07) ◽  
pp. 811-816 ◽  
Author(s):  
Toyohisa FUJITA ◽  
Toshio MIYAZAKI ◽  
Toshiharu TANAKA ◽  
Ke Jun Liu ◽  
Eiich KUZUNO ◽  
...  
Keyword(s):  
Electric Field ◽  
Silicone Oil ◽  
Small Distance ◽  
Surface Forces ◽  
Attraction Force ◽  
Interaction Forces ◽  
Repulsive Energy ◽  
Inflection Points ◽  
Dc Electric Field ◽  
Er Fluid

The apparatus to measure interaction forces under an electric field at small distance between a conductive hemisphere and a flat plate has been developed. The surface forces at small distance sandwiched ER fluid dispersing ultrafine smectite particles (20 to 50 nm thickness) in silicone oil has been measured. This fluid shows 0.7 kPa of apparent yield stress by applying 2.5 kV/mm of DC electric field. When an electric field applies to this ER fluid, the repulsive energy curves shows inflection points at about 0.2 μ m distance periodically at small distance of less than 1 μ m because the repulsion force decreases for a vacancy of particles after the particles are pushed out and the dipole attraction force acts between hemisphere and plate. On the other hand, when the electric field becomes off and it passes enough time, the inflection points is observed more shorter distance of about 0.15 μ m periodically. The coagulated particle size is estimated about 0.15 μ m under no electric field and becomes larger by applying electric field.

scholarly journals Internal Structure and ER Properties in ER Suspensions of Disperse System under DC Electric Field

1999 ◽  
Vol 119 (6) ◽  
pp. 750-757
Author(s):  
Ryoichi Hanaoka ◽  
Koji Hotta ◽  
Hidenobu Anzai ◽  
Koji Sakurai ◽  
Shinichi Kuroda
Keyword(s):  
Electric Field ◽  
Internal Structure ◽  
Disperse System ◽  
Dc Electric Field

scholarly journals Electric Field Interaction with Hydrocarbon Flames

2018 ◽  
Vol 63 (5) ◽  
pp. 402
Author(s):  
S. G. Orlovskaya ◽  
M. S. Skoropado ◽  
F. F. Karimova ◽  
V. Ya. Chernyak ◽  
L. Yu. Vergun
Keyword(s):  
Melting Point ◽  
Field Strength ◽  
Electric Field ◽  
Fossil Fuels ◽  
Melting Process ◽  
Melting Rate ◽  
Melting Time ◽  
Field Interaction ◽  
Hydrocarbon Flames ◽  
Dc Electric Field

The problem of electric-field-assisted combustion for low-melting point hydrocarbons (paraffin wax, n-alkanes) attracts the attention of scientists in relation to the development of paraffin-based propellants. Our study is aimed at the detailed investigation of the dc electric field interaction with the flame of octadecane droplet. We have studied the melting and combustion of alkane particles in the electric field ranging from 33 kV/m to 117 kV/m. It is found that the melting rate decreases distinctly starting with the electric field strength E ∼ 80 kV/m. This effect is more pronounced at high gas temperatures (Ste >1), when the melting time is about a few seconds. So, the melting process slows down in the dc electric field. At the same time, the burning rate constant rises by more than 10 percents. The obtained results can be used to develop efficient and clean technologies of fossil fuels combustion.

ELECTRORHEOLOGY OF DISPERSIONS OF BaxSr(1-x)TiO3 IN SILICONE OIL UNDER AC OR DC ELECTRIC FIELD

2012 ◽  
Vol 26 (14) ◽  
pp. 1250081 ◽  
Author(s):  
GLAUBER M. S. LUZ ◽  
ANTONIO J. F. BOMBARD ◽  
SILVIO L. M. BRITO ◽  
DOUGLAS GOUVÊA ◽  
SHEILA L. VIEIRA
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Electric Field ◽  
Silicone Oil ◽  
Ferroelectric Materials ◽  
Dc Electric Field ◽  
Ac Fields ◽  
Er Fluid ◽  
Constant Shear Rate

Electrorheology (ER) of ferroelectric materials such as nanometric BaTiO 3 is still not fully understood. In this paper, nanoparticles of Ba x Sr (1-x) TiO 3 (where x = 0.8, 0.9 or 1.0) were synthesized using the method of Pechini, calcinated at 950°C, and after, lixiviated under pH 1 or pH 5. A controlled stress rheometer (MCR-301) was used to make the ER characterization of dispersions made of Ba x Ti 1-x O 3 in silicone oil (30% w/w), where (a) shear stress as a function of DC electric field (under constant shear rate) or (b) shear stress as a function of shear rate (under constant AC or DC electric field) were measured. We observed that electrophoresis occurred under electric field DC, creating a concentration gradient which induced phase separation in ER fluid. On the other hand, under AC fields above 1 kV/mm, the ER effect is stronger than for DC field, and almost without electrophoresis. Furthermore, there is an AC frequency, dependent on the disperse phase, where the ER effect has a maximum.

Bubble Formation in a DC Electric Field

2008 ◽  
Author(s):  
Feng Chen ◽  
Yaozu Song ◽  
Yao Peng
Keyword(s):  
Aspect Ratio ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Bubble Growth ◽  
Growth Process ◽  
Major Axis ◽  
Minor Axis ◽  
Electric Stress ◽  
Dc Electric Field

The effect of a DC electric field on the formation and the characteristics of a nitrogen bubble injected from an orifice were studied experimentally and theoretically. This study was the first to divide the bubble growth process into four stages (waiting, expansion, deformation and detachment) according to the variation of the bubble shape in order to analyze the bubble behavior in the electric field. During the waiting stage, the waiting interval decreases significantly as the electric field strength rises. In the expansion stage, the minor axis reaches a maximum that decreases with increasing the electric field strength. Within the deformation stage, the major axis achieves its maximum and so does the aspect ratio. As the electric field strength rises, both the maximums of the major axis and the aspect ratio increase. At the detachment stage, as the electric field strength is intensified, the major axis lengthens, the minor axis shortens and the aspect ratio lengthens. From the waiting stage to the detachment stage, the effect of the electric field on the major axis of the bubble is marginal, while with increasing the electric field strength, the minor axis decreases distinctly and thus the aspect ratio increases. To employ the four-stage model, the bubble growth process was analyzed in detail under the electric field. The electric stress exerted on the bubble surface was calculated. The results show that the electric stress compresses the bubble equator and elongates the poles of the bubble, causing the bubble to elongate along the electric field direction.

Visualization of a Single Boiling Bubble in a DC Electric Field

2011 ◽  
Author(s):  
Feng Chen ◽  
Dong Liu ◽  
Yaozu Song ◽  
Yao Peng
Keyword(s):  
Heat Transfer ◽  
Life Cycle ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Wall Temperature ◽  
Boiling Heat Transfer ◽  
Bubble Dynamics ◽  
Nucleate Boiling ◽  
Dc Electric Field

The application of electric field has been demonstrated as an effective way to enhance pool boiling heat transfer. In past studies, adiabatic experiments were often conducted to simulate the dynamics of nucleate bubbles in the presence of an electric field, where gas bubbles were injected from an orifice, to avoid complexities involved in the nucleate boiling experiments. While adiabatic studies yield useful information of the bubble dynamics, further studies about bubble dynamics during nucleate boiling heat transfer are still necessary for a full understanding of the effects of applied electric field on the liquid-vapor phase change heat transfer. In this paper, the dynamics of a single boiling bubble in a direct current (DC) electric field was studied experimentally employing R113 as the working fluid. The life cycle of the boiling bubble was visualized using high-speed photography and was compared with that of an injected nitrogen bubble. Under the same electric field, a more appreciable elongation along the field direction was observed for the boiling bubble. A modified relationship between the bubble deformation and the electrical Weber number was proposed for the boiling bubble. As the electric field strength increases, it was found that, although the growth time of the boiling bubble increases, the waiting period decreases. However, it was also found that, the change of the whole life cycle with electric field strength increasing is relevant to the wall temperature. In this work, the wall temperature measured in the vicinity of the nucleation site upon the bubble departure decreases when the electric field is applied.

Investigation of vibration damping properties of electroactive polyanthracene/silicone oil dispersions

2021 ◽  
pp. 1045389X2110235
Author(s):  
Gokce Calis Ismetoglu ◽  
Halil Ibrahim Unal
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Silicone Oil ◽  
Vibration Damping ◽  
Elastic Behavior ◽  
Creep Recovery ◽  
Damping Properties ◽  
Sem Image ◽  
Er Fluids

Electrorheological (ER) fluids generate mechanical responses to applied electric field strength via changing their rheological properties from liquid to solid and vice-versa reversibly. As a result of this, ER fluids can be used in the industrial vibration damping systems. In order to increase applicability of ER fluids, it is necessary to understand electric field induced polarization and ER mechanism of different materials. Therefore, the aim of this study is to illuminate ER and vibration damping properties of polyanthracene (PAT), which is a new material for ER studies. PAT was synthesized from anthracene and characterized by several techniques namely: ATR-FTIR spectroscopy, particle size, SEM image, four-point probe conductivity, and magnetic susceptibility measurements. A series of PAT/silicone oil (SO) dispersions having various concentrations were prepared and subjected to dielectric and ER tests. Then, the colloidal stabilities of 20% PAT/SO and 20% PAT/SO/TritonX systems were determined. Dynamic viscoelastic data obtained by the oscillation tests showed that viscous behavior was dominant under zero electric field, whereas elastic behavior was prevailing under external electric field strength and highlighting the vibration damping characteristics of PAT/SO dispersion. In the creep-recovery measurements, the highest %recovery was recorded to be 62% indicating potential industrial use of PAT/SO dispersion.

Sign in / Sign up

Export Citation Format

Share Document