This study presents a numerical analysis of electrokinetic mass transport in a microchannel with Joule heating effects. A nonuniform electric field caused by the presence of the Joule heating is considered in the model development. Numerical computations for electrokinetic mass transport under Joule heating effects are carried out using the Crank-Nicolson scheme of second-order accuracy in space and time for two different cases: (i) the translating interface and (ii) the dispersion of a finite sample plug. The simulations reveal that the presence of Joule heating not only causes the sample species to transport faster, but also causes the sample peak to decrease and the sample band to deviate from its flat interface or pluglike shape.

Issue Section:
Technical Briefs
Keywords:
Electrokinetic Mass Transport, Joule Heating, Crank-Nicolson Scheme, electrokinetic effects, mass transfer, channel flow, microfluidics, flow simulation, electrohydrodynamics
Topics:
Electrokinetics, Heating, Joules, Microchannels, Numerical analysis, Temperature, Electric fields
1.
Probstein, R. F., 1994, Physicochemical Hydrodynamics: An Introduction, 2nd Edition, Wiley, New York.
2.
Santiago
,
J. G.
,
2001
, “
Electroosmotic Flows in Microchannels With Finite Inertial and Pressure Forces
,”
Anal. Chem.
,
73
, pp.
2353
–
2365
.
3.
Ermakov
,
S. V.
,
Jacobson
,
S. G.
, and
Ramsey
,
J. M.
,
1998
, “
Computer Simulations of Electrokinetic Transport in Microfabricated Channels
,”
Anal. Chem.
,
70
, pp.
4494
–
4504
.
4.
Erickson
,
D.
, and
Li
,
D.
,
2002
, “
Influence of Surface Heterogeneity on Electrokinetically Driven Microfluidic Mixing
,”
Langmuir
,
18
, pp.
1883
–
1892
.
5.
Zholkovskij
,
E. K.
,
Masliyah
,
J. H.
, and
Czarnecki
,
J.
,
2003
, “
Electroosmotic Dispersion in Microchannels With a Thin Double Layer
,”
Anal. Chem.
,
75
, pp.
901
–
909
.
6.
Knox
,
J. H.
, and
McCormack
,
K. A.
,
1994
, “
Temperature Effects in Capillary Electrophoresis: Internal Capillary Temperature and Effect Upon Performance
,”
Chromatographia
,
38
, pp.
207
–
214
.
7.
Grushka
,
E.
,
McCormick
,
R. M.
, and
Kirkland
,
J. J.
,
1989
, “
Effect of Temperature Gradients on Efficiency of Capillary Zone Electrophoresis Separations
,”
Anal. Chem.
,
61
, pp.
241
–
246
.
8.
Tang
,
G. Y.
,
Yang
,
C.
,
Chai
,
C. K.
, and
Gong
,
H. Q.
,
2003
, “
Modeling of Electroosmotic Flow and Capillary Electrophoresis With the Joule Heating Effect: The Nernst-Planck Equation Versus the Boltzmann Distribution
,”
Langmuir
,
19
, pp.
10975
–
10984
.
9.
Tang
,
G. Y.
,
Yang
,
C.
,
Chai
,
C. K.
, and
Gong
,
H. Q.
,
2004
, “
Joule Heating Effect on Electroosmotic Flow and Mass Species Transport in a Microcapil-lary
,”
Int. J. Heat Mass Transfer
,
47
, pp.
215
–
227
.
10.
Noye, B. P., 1976, “An Introduction to Finite Difference Techniques,” Proceeding of an International Conference on the Numerical Simulation of Fluid Dynamics, North-Holland-Elsevier, New York, pp. 56–85.
11.
Patankar, S. V., 1980, Numerical Heat Transfer and Fluid Flow, McGraw-Hill, New York.
12.
Crank
,
J.
, and
Nicolson
,
P.
,
1947
, “
A Practical Method for Numerical Evaluation of Solutions of Partial Differential Equations of the Heat-ConductionType
,”
Proc. Cambridge Philos. Soc.
,
43
, pp.
50
–
67
.
13.
Paul
,
P. H.
,
Garguilo
,
M. G.
, and
Rakestraw
,
D. J.
,
1998
, “
Imaging of Pressure- and Electrokinetically Driven Flows Through Open Capillaries
,”
Anal. Chem.
,
70
, pp.
2459
–
2467
.
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