We investigate electro-osmosis in aqueous solutions of polyelectrolytes using mean-field equations. A solution of positively charged polyelectrolytes is confined between two negatively charged planar surfaces, and an electric field is applied parallel to the surfaces. When electrostatic attraction between the polymer and the surface is strong, the polymers adhere to the surface, forming a highly viscous adsorption layer that greatly suppresses the electro-osmosis. Conversely, electro-osmosis is enhanced by depleting the polymers from the surfaces. We also found that the electro-osmotic flow is invertible when the electrostatic potential decays to its bulk value with the opposite sign. These behaviors are well explained by a simple mathematical form of the electro-osmotic coefficient.

1.
M.
Rubinstein
and
G. A.
Papoian
,
Soft Matter
8
,
9265
(
2012
), and references therein.
2.
F.
Oosawa
,
Polyelectrolytes
(
Marcel Dekker, Inc.
,
1971
).
3.
P. G.
de Gennes
,
Scaling Concepts in Polymer Physics
(
Cornell University Press
,
1979
).
4.
J. F.
Joanny
and
L.
Leibler
,
J. Phys. (France)
51
,
545
(
1990
).
5.
J. L.
Barrat
and
J. F.
Joanny
,
Adv. Chem. Phys.
94
,
1
(
1996
).
6.
A. V.
Dobrynin
and
M.
Rubinstein
,
Prog. Polym. Sci.
30
,
1049
(
2005
).
7.
T.
Igarashi
 et al,
Kobunshi Rombunshu
48
,
751
(
1991
).
8.
M.
Liu
and
J.
Yang
,
Microvasc. Res.
78
,
14
(
2009
).
9.
R. W.
O’Brien
and
L. R.
White
,
J. Chem. Soc., Faraday Trans. 2
74
,
1607
(
1978
).
10.
D.
Burgreen
and
F. R.
Nakache
,
J. Phys. Chem.
68
,
1084
(
1964
).
11.
C. L.
Rice
and
R.
Whitehead
,
J. Phys. Chem.
69
,
4017
(
1965
).
12.
B. S.
Levine
,
J. R.
Marriott
, and
K.
Robinson
,
J. Chem. Soc., Faraday Trans. 2
71
,
1
(
1975
).
13.
J. F.
Joanny
,
L.
Leibler
, and
P. G.
de Gennes
,
J. Polym. Sci., Poym. Phys. Ed.
17
,
1073
(
1979
).
14.
P. G.
de Gennes
,
Macromolecules
14
,
1637
(
1981
).
15.
P. G.
de Gennes
,
Macromolecules
15
,
492
(
1982
).
16.
I.
Borukhov
,
D.
Andelman
, and
H.
Orland
,
Europhys. Lett.
32
,
499
(
1995
).
17.
X.
Châtellier
and
J. F.
Joanny
,
J. Phys. II France
6
,
1669
(
1996
).
18.
I.
Borukhov
,
D.
Andelman
, and
H.
Orland
,
Macromolecules
31
,
1665
(
1998
).
19.
J. F.
Joanny
,
Eur. Phys. J. B
9
,
117
(
1999
).
20.
A.
Shafir
,
D.
Andelman
, and
R. R.
Netz
,
J. Chem. Phys.
119
,
2355
(
2003
).
21.
A.
Shafir
and
D.
Andelman
,
Phys. Rev. E
70
,
061804
(
2004
).
22.
H.
Vink
,
J. Chem. Soc., Faraday Trans. 1
84
,
133
(
1988
).
23.
M. S.
Bello
 et al,
Electrophoresis
15
,
623
(
1994
).
25.
C.
Zhao
,
E.
Zholkovskij
,
J. H.
Masliyah
, and
C.
Yang
,
J. Colloid Interface Sci.
326
,
503
(
2008
).
26.
M. L.
Olivares
,
L.
Vera-Candioti
, and
C. L. A.
Berli
,
Electrophoresis
30
,
921
(
2009
).
27.
C.
Zhao
and
C.
Yang
,
J. Non-Newtonian Fluid Mech.
166
,
1076
(
2011
).
28.
A. V.
Dobrynin
,
R. H.
Colby
, and
M.
Rubinstein
,
Macromolecules
28
,
1859
(
1995
).
29.
A. Yu.
Grosberg
,
T. T.
Nguyen
, and
B. I.
Shklovskii
,
Rev. Mod. Phys.
74
,
329
(
2002
).
30.
R.
Qiao
and
N. R.
Aluru
,
Phys. Rev. Lett.
92
,
198301
(
2004
).
You do not currently have access to this content.