Velocity measurements inside the diffuse electric double layer in electro-osmotic flow

2006 ◽  
Vol 89 (4) ◽  
pp. 044103 ◽  
Author(s):  
Reza Sadr ◽  
Minami Yoda ◽  
Pradeep Gnanaprakasam ◽  
A. Terrence Conlisk
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Velocity Measurements ◽  
Osmotic Flow ◽  
Electro Osmotic Flow

Exact Solution of AC Electro-Osmotic Flow in a Microannulus

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Ali Jabari Moghadam
Keyword(s):  
Exact Solution ◽  
Double Layer ◽  
Electric Double Layer ◽  
Maximum Velocity ◽  
Velocity Profiles ◽  
Radius Ratio ◽  
Dimensionless Frequency ◽  
Ζ Potential ◽  
Osmotic Flow ◽  
Electro Osmotic Flow

The time-periodic electro-osmotic flow in a microannulus is investigated based on the linearized Poisson–Boltzmann equation. An exact solution of the velocity distribution is obtained by using the Green's function approach. The influences of the geometric radius ratio, the wall ζ potential ratio, the electrokinetic radius, and the dimensionless frequency on velocity profiles are presented. Variations of the geometric radius ratio (between zero and one) can lead to quite different flow behaviors. The wall ζ potential ratio affects the magnitude and direction of the velocity profiles within the electric double layer near the two walls of a microannulus. Depending on the frequency and the geometric radius ratio, the walls identically and/or oppositely charged, both may result in the two-opposite-direction flow in the annulus. For high frequency, the electro-osmotic velocity variations are restricted mainly within a thin layer near the two cylindrical walls. Increasing the electrokinetic radius leads to decrease the electric double layer thickness as well as the maximum velocity near the walls.

scholarly journals INFLUENCE OF THE ELECTRIC DOUBLE LAYER ON INDUCED PRESSURE FIELDS AND DEVELOPMENT LENGTHS IN ELECTRO-OSMOTIC FLOWS

2005 ◽  
Vol 19 (28n29) ◽  
pp. 1655-1658
Author(s):  
YONGHAO ZHANG ◽  
XIAO-JUN GU ◽  
ROBERT W. BARBER ◽  
DAVID R. EMERSON
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Pressure Field ◽  
Volumetric Flow Rate ◽  
Channel Height ◽  
Fluid Viscosity ◽  
Development Length ◽  
Pressure Fields ◽  
Flow Development ◽  
Electro Osmotic Flow

Electro-osmotic flow can be used as an efficient pumping mechanism in microfluidic devices. For this type of flow, frictional losses at the entrance and exit can induce an adverse longitudinal pressure distribution that can lead to dispersive effects. The present study describes a numerical investigation of the influence of the electric double layer on the induced pressure field and the flow development length. The induced pressure gradient is affected by the volumetric flow rate, fluid viscosity and the channel height. When the electric double layer is small, the development length remains constant at 0.57 of the channel height but decreases as the double layer grows in thickness.

LATTICE BOLTZMANN SIMULATION OF VISCOUS DISSIPATION IN ELECTRO-OSMOTIC FLOW IN MICROCHANNELS

2007 ◽  
Vol 18 (07) ◽  
pp. 1119-1131 ◽  
Author(s):  
ZHEN-HUA CHAI ◽  
BAO-CHANG SHI ◽  
LIN ZHENG
Keyword(s):  
Viscous Dissipation ◽  
Lattice Boltzmann ◽  
Electric Double Layer ◽  
Governing Equations ◽  
Osmotic Flow ◽  
Lattice Boltzmann Simulation ◽  
Lattice Boltzmann Models ◽  
Boltzmann Method ◽  
Electro Osmotic Flow ◽  
High Velocity Gradient

In this paper, the effects of viscous dissipation in electro-osmotic flow in microchannels are numerically analyzed with lattice Boltzmann method (LBM), and three different lattice Boltzmann models that can recover the macroscopic governing equations for electro-osmotic flow (EOF) are proposed. As the dimensions of the channels approach the microlevel, viscous dissipation could be significant due to a high velocity gradient in electric double layer (EDL). Numerical results show that viscous dissipation plays an important role in EOF in microchannels.

Electrode for Electric Double Layer Capacitor Made of Carbonized and Activated Cotton Cloth

2014 ◽  
Vol 134 (5) ◽  
pp. 360-361
Author(s):  
Masumi Fukuma ◽  
Takayuki Uchida ◽  
Yukito Fukushima ◽  
Jinichi Ogawa ◽  
Katsumi Yoshino
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Cotton Cloth ◽  
Electric Double Layer Capacitor ◽  
Double Layer Capacitor
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