scholarly journals The zero-shear-rate limiting rheological behaviors of ideally conductive particles suspended in concentrated dispersions under an electric field

2021 ◽  
Vol 65 (1) ◽  
pp. 13-26
Author(s):  
Siamak Mirfendereski ◽  
Jae Sung Park
Keyword(s):  
Shear Rate ◽  
Electric Field ◽  
Rheological Behaviors ◽  
Conductive Particles ◽  
Rate Limiting ◽  
Concentrated Dispersions

Flow Behaviors of High Acyl Gellan Aqueous Solutions as Affected by Temperature, and Calcium and Gellan Concentrations

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Yiqun Huang ◽  
Pawan Singh Takhar ◽  
Juming Tang ◽  
Barry G Swanson
Keyword(s):  
Shear Rate ◽  
Aqueous Solutions ◽  
Apparent Viscosity ◽  
Flow Resistance ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Rheological Behaviors ◽  
Low Concentrations ◽  
Influence Of Temperature On

Rheological behaviors of high acyl (HA) gellan are not well understood partially because of its relatively late commercialization compared to low acyl gellan. The objective of this study was to investigate the effect of temperature (5-30 °C), calcium (0, 1 and 10 mM) and gellan concentrations (0.0044-0.1000% w/v) on the flow behaviors of high acyl gellan aqueous solutions using rheological tests. Gellan solutions with 0 or 1 mM added Ca++ exhibited shear thinning behavior at gellan concentrations above 0.0125%. The influence of temperature on apparent viscosity (shear rate, 100 s-1) of gellan solutions can be described with an Arrhenius relationship. The apparent viscosity of gellan solution at low concentrations was more sensitive to temperature changes. The addition of Ca++ led to a decrease in flow resistance for a dilute gellan solution (<0.0125%), but an increased resistance for a relatively concentrated gellan solution (>0.0125%).

HYDRODYNAMIC CHARACTERISTICS OF ELECTRORHEOLOGICAL FLUID IN A PARALLEL DUCT FLOW

2001 ◽  
Vol 15 (06n07) ◽  
pp. 980-987
Author(s):  
K. SHIMADA ◽  
S. KAMIYAMA
Keyword(s):  
Shear Rate ◽  
Friction Coefficient ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Apparent Viscosity ◽  
Wall Friction ◽  
Hydrodynamic Characteristics ◽  
Duct Flow ◽  
Newtonian Viscosity

An experimental investigation is conducted to clarify the hydrodynamic characteristics of ERF with elastic particles of smectite in a two-dimensional parallel duct of various widths. Experimental data on pressure difference to a volumetric flow rate in a supplying D.C. electric field are measured. These data are arranged to obtain the apparent viscosit by using the integral method of rheology. From the data of apparent viscosity, the wall friction coefficient is obtained. The increment of the apparent viscosity caused by the applying electric field is a function of shear rate as well as the electric field strength and the width of the duct. However, the wall friction coefficient is not a function of elecric field strength and the width of the parallel duct, but only of shear rate. The yield stress is a function of the width of the parallel duct as well as of electric field strength. The ratio of Non-Newtonian viscosity in the apparent viscosity is varied by the intensity of the shear rate.

DIFFERENCES IN STEADY CHARACTERISTICS AND RESPONSE TIME OF ERF ON ROTATIONAL FLOW BETWEEN ROTATING DISK AND CONCENTRIC CYLINDER

2001 ◽  
Vol 15 (06n07) ◽  
pp. 1050-1056 ◽  
Author(s):  
K. SHIMADA ◽  
H. NISHIDA ◽  
T. FUJITA
Keyword(s):  
Shear Rate ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Current Density ◽  
Rotating Disk ◽  
Settling Time ◽  
Rotational Flow ◽  
Concentric Cylinder ◽  
Constant Shear Rate

We made an experimental investigation of the steady characteristics of torque, current density, and response time of ERF on rotational flow of the disk and the concentric cylinder. We used smectite particles suspension ERF and D.C. electric field. We compared the steady shearstress, current density, and the rise and settling time of the concentric cylinder and with those of the rotating disk. Then we clarified the differences. At a larger electric field strength, the shear stress, yield stress, and apparent viscosity to a constant shear rate in the case of the rotating disk are larger than they are in the case of the rotating concentric cylinder. However, at a larger electric field strength, the current density to a constant shear rate in the case of the rotating disk is smaller than it is in the case of the rotating concentric cylinder. Rise time of torque in the case of the rotating disk is faster than it is in the case of the rotating concentric cylinder. However, rise time of current density in the case of the rotating disk is slower than it is in the case of the rotating concentric cylinder at a small electric field strength. On the other hand, the difference of settling time of torque and current density between the rotating disk and the rotating concentric cylinder is changed by the electric field strength and shear rate. The settling time of torque in the case of the rotating disk is faster than it is in the case of the rotating concentric cylinder at a large electric field strength and large shear rate. The settling time of current density in the case of the rotating disk is slower than it is in the case of rotating concentric cylinder at a small electric field strength. Based on these results, the rotating disk has an efficiency of obtained torque to given electric power greater than that of the rotating concentric cylinder.

scholarly journals Electric Field Assisted Self-Healing of Open Circuits with Conductive Particle-Insulating Fluid Dispersions: Optimizing Dispersion Concentration

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Virendra Parab ◽  
Oppili Prasad ◽  
Sreelal Pillai ◽  
Sanjiv Sambandan
Keyword(s):  
Electric Field ◽  
Flexible Electronics ◽  
Image Sensor ◽  
Electronic Systems ◽  
Self Healing ◽  
Wearable Electronics ◽  
Large Area ◽  
Open Faults ◽  
The Impact ◽  
Conductive Particles

AbstractOpen circuit faults in electronic systems are a common failure mechanism, particularly in large area electronic systems such as display and image sensor arrays, flexible electronics and wearable electronics. To address this problem several methods to self heal open faults in real time have been investigated. One approach of interest to this work is the electric field assisted self-healing (eFASH) of open faults. eFASH uses a low concentration dispersion of conductive particles in an insulating fluid that is packaged over the interconnect. The electric field appearing in the open fault in a current carrying interconnect polarizes the conductive particles and chains them up to create a heal. This work studies the impact of dispersion concentration on the heal time, heal impedance and cross-talk when eFASH is used for self-healing. Theoretical predictions are supported by experimental evidence and an optimum dispersion concentration for effective self-healing is identified.

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.

The Rheological Behaviors of Nylon610 and Nylon610/Montmorillonite Nanocomposites

2011 ◽  
Vol 183-185 ◽  
pp. 1726-1730 ◽  
Author(s):  
Qian Wang ◽  
Cheng Shen Zhu ◽  
Ping Du ◽  
Su Qin He
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Apparent Viscosity ◽  
Effect Of Temperature ◽  
Pseudoplastic Fluid ◽  
Rheological Behaviors ◽  
Lower Shear ◽  
Lower Shear Rate ◽  
Montmorillonite Nanocomposites

The rheological behaviors of nylon610 and nylon610/montmorillonite nanocomposites had been studied by means of HAAKE-Ⅱrheometer. The results showed that nylon610 and nylon610/montmorillonite composites were pseudoplastic fluid. The non-Newtonian indexes, which were in the range of 0.49～0.82 at differern temperatures, decreased with the addition of montmorillonite. What is more, the apparent viscous activation energy decreased, which showed the effect of temperature on apparent viscosity of the nanocomposites was weaker than that of pure nylon610, apparent viscosity increased with the increase of montmorillonite, especially at the lower shear rate.

Synthesis, characterization and electrorheological properties of biodegradable chitosan/bentonite composites

Clay Minerals ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 129-141 ◽  
Author(s):  
M. Cabuk ◽  
M. Yavuz ◽  
H. I. Unal ◽  
O. Erol
Keyword(s):  
Particle Size ◽  
Shear Rate ◽  
Electric Field ◽  
Cetyltrimethylammonium Bromide ◽  
Particle Concentration ◽  
Silicone Oil ◽  
Creep Recovery ◽  
Field Frequency ◽  
Electric Field Frequency ◽  
Electrorheological Properties

AbstractBiodegradable chitosan/bentonite composites with three different compositions were synthesized by the intercalation method using cetyltrimethylammonium bromide as the cationic surfactant. The composites were characterized using conductivity, density, particle size measurements, FTIR, TGA, XRD and SEM methods. Colloidal stabilities of the suspensions prepared in silicone oil (SO) were observed to increase with decreasing density. The effects of dispersed particle concentration, shear rate, electric field strength, electric field frequency and temperature on the electrorheological (ER) activities of the suspensions were investigated. The electric field viscosities of the suspensions showed typical shear thinning non-Newtonian viscoelastic behaviour. Yield stresses of the suspensions were observed to change in proportion to the square of applied electric field (E). Further, according to creep and creep-recovery analysis, reversible viscoelastic deformations were observed in the suspensions under E ≠ 0 kV mm–1.

Experimental Variables Effecting Chain Growth in Conductive Adhesives

1996 ◽  
Vol 445 ◽  
Author(s):  
Rebecca E. Hefner ◽  
Mark A. Palmer
Keyword(s):  
Electric Field ◽  
Electrical Contact ◽  
Optimal Combination ◽  
Electronics Manufacturing ◽  
Chain Growth ◽  
Conductive Adhesives ◽  
Chain Formation ◽  
Designed Experiment ◽  
Conductive Particles ◽  
Kinetics Of

AbstractChains of conductive particles within a polymer matrix can be used in place of solder joints in electronics manufacturing. Such materials can be made such that electrical conduction occurs in only one direction. Fabricating such an electrical contact requires that the conducting particles be aligned and touching, thus providing a continuous path. This can be done by applying an electric field to a mixture containing conducting particles in a polymer. Preliminary work will be presented assessing the effect of electric field strength (applied voltage), viscosity (temperature), frequency (DC and AC) on the kinetics of chain formation. A designed experiment showed only viscosity or temperature to be statistically significant. However, it is believed that voltage and frequency are factors which will effect the chain kinetics. Specifically it is proposed that there is an optimal combination of frequency and voltage for chain formation. Based on these results a more systematic study has been proposed.

A Rheological Model of Semisolid Magnesium Alloy Slurries

2005 ◽  
Vol 488-489 ◽  
pp. 333-336 ◽  
Author(s):  
L. Li ◽  
X.W. Zhou ◽  
J.Y. Chen
Keyword(s):  
Magnesium Alloy ◽  
Shear Rate ◽  
Rheological Properties ◽  
Apparent Viscosity ◽  
Rheological Model ◽  
The State ◽  
Simple Shearing ◽  
Flow Conditions ◽  
Rheological Behaviors ◽  
Microstructure Model

In this paper a rheological model is presented which describes the rheological behaviors of liquid-like semisolid magnesium alloy under a simple shearing flow. On the basis of Chen and Fan’s mono-dispersion microstructure model of semisolid metal slurry, the particle size distribution is considered in this model. It is believed that it is the state of agglomeration which determines the rheological behaviors of the slurry, whereas the external flow conditions such as shear rate and shearing time, affect the rheological properties by changing the state of agglomeration. The expressions of collision rate between two agglomerates, effective solid fraction and the formula of apparent viscosity of Chen and Fan’s model are corrected according to the experimental results and statistical mechanics. Finally calculated apparent viscosity and the average number of the particles of AZ91D by the developed model as functions of shear rate are presented. These results show that there is a one to one coupling between the rheological properties of the magnesium alloy slurries and the state of the agglomeration.

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