By using a classical density functional theory (interfacial statistical associating fluid theory), we investigate the structure and effective forces in nonadsorbing polymer-colloid mixtures. The theory is tested under a wide range of conditions and performs very well in comparison to simulation data. A comprehensive study is conducted characterizing the role of polymer concentration, particle/polymer-segment size ratio, and polymer chain length on the structure, polymer induced depletion forces, and the colloid-colloid osmotic second virial coefficient. The theory correctly captures a depletion layer on two different length scales, one on the order of the segment diameter (semidilute regime) and the other on the order of the polymer radius of gyration (dilute regime). The particle/polymer-segment size ratio is demonstrated to play a significant role on the polymer structure near the particle surface at low polymer concentrations, but this effect diminishes at higher polymer concentrations. Results for the polymer-mediated mean force between colloidal particles show that increasing the concentration of the polymer solution encourages particle-particle attraction, while decreasing the range of depletion attraction. At intermediate to high concentrations, depletion attraction can be coupled to a midrange repulsion, especially for colloids in solutions of short chains. Colloid-colloid second virial coefficient calculations indicate that the net repulsion between colloids at low polymer densities gives way to net attraction at higher densities, in agreement with available simulation data. Furthermore, the results indicate a higher tendency toward colloidal aggregation for larger colloids in solutions of longer chains.

1.
J. Y.
Lee
,
G. A.
Buxton
, and
A. C.
Balazs
,
J. Chem. Phys.
121
,
5531
(
2004
).
2.
V.
Sinani
,
D. S.
Kokysh
,
B.-G.
Yun
,
R. L.
Matts
,
T. C.
Pappas
,
M.
Motamedi
,
S. N.
Thomas
, and
N. A.
Kotov
,
Nano Lett.
3
,
1177
(
2003
).
3.
K. A.
Smith
,
S.
Tyagi
, and
A. C.
Balazs
,
Macromolecules
38
,
10138
(
2005
).
4.
E.
Spoerke
and
S.
Stupp
,
J. Biomed. Mater. Res.
67A
,
960
(
2003
).
5.
S.
White
,
N. R.
So Hos
,
P. H.
Geubelle
,
J. S.
Moore
,
M. R.
Kessler
,
S. R.
Sriram
,
E. N.
Brown
, and
S.
Viswanathan
,
Nature (London)
409
,
794
(
2001
).
6.
S.
Asakura
and
F.
Oosawa
,
J. Polym. Sci.
33
,
183
(
1958
).
7.
S.
Asakura
and
F.
Oosawa
,
J. Chem. Phys.
22
,
1255
(
1954
).
8.
P. G.
deGennes
,
Scaling Concepts in Polymer Physics
(
Cornell University Press
,
Ithaca, NY
,
1979
).
9.
P. G.
deGennes
,
C. R. Seances Acad. Sci., Ser. B
288
,
359
(
1979
).
10.
J. R.
Joanny
,
L.
Leibler
, and
P. G. D.
Gennes
,
J. Polym. Sci., Polym. Phys. Ed.
17
,
1073
(
1979
).
11.
R. P.
Sear
,
Eur. Phys. J. B
1
,
313
(
1999
).
12.
R. P.
Sear
,
J. Chem. Phys.
115
,
575
(
2001
).
13.
E.
Eisenriegler
,
J. Chem. Phys.
113
,
5091
(
2000
).
14.
R.
Maassen
,
E.
Eisenriegler
, and
A.
Bringer
,
J. Chem. Phys.
115
,
5292
(
2001
).
15.
M.
Surve
,
V.
Pryamitsyn
, and
V.
Ganesan
,
J. Chem. Phys.
122
,
154901
(
2005
).
16.
R.
Tuinier
and
G. J.
Fleer
,
Macromolecules
37
,
8764
(
2004
).
17.
J. M.-H. M.
Scheutjens
and
G. J.
Fleer
,
Adv. Colloid Interface Sci.
16
,
361
(
1982
).
18.
S.
Yang
,
D.
Yan
,
H.
Tan
, and
A. C.
Shi
,
Phys. Rev. E
74
,
041808
(
2006
).
19.
A. P.
Chatterjee
and
K. S.
Schweizer
,
J. Chem. Phys.
109
,
10464
(
1998
).
20.
A. P.
Chatterjee
and
K. S.
Schweizer
,
J. Chem. Phys.
109
,
10477
(
1998
).
21.
M.
Fuchs
and
K. S.
Schweizer
,
J. Phys.: Condens. Matter
14
,
R239
(
2002
).
22.
M.
Fuchs
and
K. S.
Schweizer
,
Phys. Rev. E
64
,
021514
(
2001
).
23.
A.
Yethiraj
,
C. K.
Hall
, and
R.
Dickman
,
J. Colloid Interface Sci.
151
,
102
(
1992
).
24.
R.
Dickman
and
A.
Yethiraj
,
J. Chem. Phys.
100
,
4683
(
1994
).
25.
M.
Doxastakis
,
Y.-L.
Chen
, and
J. J.
de Pablo
,
J. Chem. Phys.
123
,
034901
(
2005
).
26.
M.
Doxastakis
,
Y.-L.
Chen
,
O.
Guzman
, and
J. J.
de Pablo
,
J. Chem. Phys.
120
,
9335
(
2004
).
27.
A. A.
Louis
,
P. G.
Bolhuis
, and
E. J.
Meijer
,
J. Chem. Phys.
116
,
10547
(
2002
).
28.
A. A.
Louis
,
P. G.
Bolhuis
,
E. J.
Meijer
, and
J. P.
Hansen
,
J. Chem. Phys.
117
,
1893
(
2002
).
29.
A.
Striolo
,
C. M.
Colina
,
K. E.
Gubbins
,
N.
Elvassore
, and
L.
Lue
,
Mol. Simul.
30
,
437
(
2004
).
30.
J. B.
Hooper
,
K. S.
Schweizer
,
T. G.
Desai
,
R.
Koshy
, and
P.
Keblinski
,
J. Chem. Phys.
121
,
6986
(
2004
).
31.
N.
Patel
and
S. A.
Egorov
,
J. Chem. Phys.
121
,
4987
(
2004
).
33.
R.
Tuinier
,
H. N. W.
Lekkerkerker
, and
D. G. A. L.
Aarts
,
Phys. Rev. E
65
,
060801
(
2002
).
34.
R.
Tuinier
,
G. A.
Vliegenthart
, and
H. N. W.
Lekkerkerker
,
J. Chem. Phys.
113
,
10768
(
2000
).
35.
X.
Chen
,
J.
Cai
,
H.
Liu
, and
Y.
Hu
,
Mol. Simul.
32
,
877
(
2006
).
36.
S. C.
Kim
and
S. H.
Lee
,
Mol. Phys.
104
,
1487
(
2006
).
37.
Z.
Li
and
J.
Wu
,
J. Chem. Phys.
126
,
144904
(
2007
).
38.
S.
Tripathi
and
W. G.
Chapman
,
J. Chem. Phys.
122
,
094506
(
2005
).
39.
C. E.
Woodward
and
A.
Yethiraj
,
J. Chem. Phys.
100
,
3181
(
1994
).
40.
B. C.
Freasier
and
C. E.
Woodward
,
Comput. Theor. Polym. Sci.
9
,
141
(
1999
).
41.
J. P.
Hansen
and
I. R.
McDonald
,
Theory of Simple Liquids
, 3rd ed. (
Academic
,
San Diego
,
2006
).
42.
J. G.
Kirkwood
,
J. Chem. Phys.
3
,
300
(
1935
).
43.
B. V.
Derjaguin
,
Kolloid-Z.
69
,
155
(
1934
).
44.
P.
Attard
,
J. Chem. Phys.
91
,
3083
(
1989
).
45.
T.
Biben
,
P.
Bladon
, and
D.
Frenkel
,
J. Phys.: Condens. Matter
8
,
10799
(
1996
).
46.
A. A.
Louis
,
E.
Allahyarov
,
H.
Lowen
, and
R.
Roth
,
Phys. Rev. E
65
,
061407
(
2002
).
47.
B.
Gotzelmann
,
R.
Evans
, and
S.
Dietrich
,
Phys. Rev. E
57
,
6785
(
1998
).
48.
Y.
Mao
,
M. E.
Cates
, and
H. N. W.
Lekkerkerker
,
Physica A
222
,
10
(
1995
).
49.
R.
Roth
,
R.
Evans
, and
S.
Dietrich
,
Phys. Rev. E
62
,
5360
(
2000
).
50.
J. R.
Henderson
,
Mol. Phys.
50
,
741
(
1983
).
51.
X.
Chen
,
J.
Cai
,
H.
Lui
, and
Y.
Hu
,
Mol. Simul.
32
,
877
(
2006
).
52.
M. S.
Wertheim
,
J. Stat. Phys.
35
,
19
(
1984
).
53.
M. S.
Wertheim
,
J. Stat. Phys.
35
,
35
(
1984
).
54.
M. S.
Wertheim
,
J. Stat. Phys.
42
,
459
(
1986
).
55.
M. S.
Wertheim
,
J. Stat. Phys.
42
,
477
(
1986
).
56.
C. E.
Woodward
,
J. Chem. Phys.
94
,
3183
(
1991
).
57.
A.
Yethiraj
and
C. E.
Woodward
,
J. Chem. Phys.
102
,
5499
(
1995
).
58.
S.
Tripathi
and
W. G.
Chapman
,
Phys. Rev. Lett.
94
,
087801
(
2005
).
59.
A.
Dominik
,
S.
Tripathi
, and
W. G.
Chapman
,
Ind. Eng. Chem. Res.
45
,
6785
(
2006
).
60.
S.
Jain
,
A.
Dominik
, and
W. G.
Chapman
,
J. Chem. Phys.
127
,
244904
(
2007
).
61.
S.
Jain
,
P.
Jog
,
J.
Weinhold
,
R.
Srivastava
, and
W. G.
Chapman
,
J. Chem. Phys.
128
,
154910
(
2008
).
62.
R.
Evans
, in
Fundamentals of Inhomogeneous Fluids
, edited by
D.
Henderson
(
Dekker
,
New York
,
1992
), pp.
85
175
.
63.
64.
65.
D. A.
McQuarrie
,
Statistical Mechanics
(
University Science Books
,
Sausalito
,
2000
).
66.
Z.
Li
,
D.
Cao
, and
J.
Wu
,
J. Chem. Phys.
122
,
174708
(
2005
).
67.
N.
Patel
and
S. A.
Egorov
,
J. Chem. Phys.
123
,
144916
(
2005
).
68.
W. G.
Chapman
, Ph.D. thesis
Cornell University
,
1988
.
69.
C. J.
Segura
,
W. G.
Chapman
, and
K. S.
Shukla
,
Mol. Phys.
90
,
759
(
1997
).
70.
N. F.
Carnahan
and
K. E.
Starling
,
J. Chem. Phys.
51
,
635
(
1969
).
71.
J.
Dautenhahn
and
C. K.
Hall
,
Macromolecules
27
,
5399
(
1994
).
72.
P. G.
Bolhuis
,
E. J.
Meijer
, and
A. A.
Louis
,
Phys. Rev. Lett.
90
,
068304
(
2003
).
73.
K. S.
Schweizer
and
J. G.
Curro
,
Phys. Rev. Lett.
60
,
809
(
1988
).
74.
K. S.
Schweizer
and
J. G.
Curro
,
Adv. Polym. Sci.
116
,
319
(
1994
).
75.
K. S.
Schweizer
and
J. G.
Curro
,
Adv. Chem. Phys.
98
,
1
(
1997
).
76.
J.
Percus
and
G.
Yevick
,
Phys. Rev.
110
,
1
(
1958
).
77.
R. C.
Picu
and
M. S.
Ozmusul
,
J. Chem. Phys.
118
,
11239
(
2003
).
78.
P. M.
Konig
,
R.
Roth
, and
S.
Dietrich
,
Phys. Rev. E
74
,
041404
(
2006
).
79.
D.
Bedrov
,
G. D.
Smith
, and
J. S.
Smith
,
J. Chem. Phys.
119
,
10438
(
2003
).
80.
J. S.
Smith
,
D.
Bedrov
, and
G. D.
Smith
,
Compos. Sci. Technol.
63
,
1599
(
2003
).
81.
M.
Muller
,
L. G.
MacDowell
, and
A.
Yethiraj
,
J. Chem. Phys.
118
,
2929
(
2003
).
82.
C. N.
Patra
and
A.
Yethiraj
,
J. Chem. Phys.
112
,
1579
(
2000
).
83.
C. N.
Patra
and
A.
Yethiraj
,
J. Chem. Phys.
118
,
4702
(
2003
).
You do not currently have access to this content.