Structural hydrogel materials are being considered and investigated for a wide variety of biotribological applications. Unfortunately, most of the mechanical strength and rigidity of these materials comes from high polymer concentrations and correspondingly low polymer mesh size, which results in high friction coefficients in aqueous environments. Recent measurements have revealed that soft, flexible, and large mesh size hydrogels can provide ultra low friction, but this comes at the expense of mechanical strength. In this paper, we have prepared a low friction structural hydrogel sample of polyhydroxyethylmethacrylate (pHEMA) by polymerizing an entangled polymer network on the surface through a solution polymerization route. The entangled polymer network was made entirely from uncrosslinked polyacrylamide (pAAm) that was polymerized from an aqueous solution and had integral entanglement with the pHEMA surface. Measurements revealed that these entangled polymer networks could extend up to ∼200 μm from the surface, and these entangled polymer networks can provide reductions in friction coefficient of almost two orders of magnitude (μ > 0.7 to μ < 0.01).

References

References
1.
Batra
,
S. K.
, and
Ling
,
F. F.
,
1967
, “
On Deformation Friction and Interface Shear Stress in Viscoelastic-Elastic Layered System Under a Moving Load
,”
ASLE Trans.
,
10
(
3
), pp.
294
301
.
2.
Ling
,
F. F.
,
Lai
,
W. M.
, and
Lucca
,
D. A.
,
2002
,
Fundamentals of Surface Mechanics
,
Springer
,
New York
.
3.
Dunn
,
A. C.
,
Urueña
,
J. M.
,
Huo
,
Y.
,
Perry
,
S. S.
,
Angelini
,
T. E.
, and
Sawyer
,
W. G.
,
2013
, “
Lubricity of Surface Hydrogel Layers
,”
Tribol. Lett.
,
49
(
2
), pp.
371
378
.
4.
Katta
,
J. K.
,
Marcolongo
,
M.
,
Lowman
,
A.
, and
Mansmann
,
K. A.
,
2007
, “
Friction and Wear Behavior of Poly(Vinyl Alcohol)/Poly(Vinyl Pyrrolidone) Hydrogels for Articular Cartilage Replacement
,”
J. Biomed. Mater. Res. A
,
83
(
2
), pp.
471
479
.
5.
Yang
,
S. H.
,
Lee
,
Y. S. J.
,
Lin
,
F. H.
,
Yang
,
J. M.
, and
Chen
,
K. S.
,
2007
, “
Chitosan/Poly(Vinyl Alcohol) Blending Hydrogel Coating Improves the Surface Characteristics of Segmented Polyurethane Urethral Catheters
,”
J. Biomed. Mater. Res. B Appl. Biomater.
,
83
(
2
), pp.
304
313
.
6.
Kim
,
S. H.
,
Marmo
,
C.
, and
Somorjai
,
G. A.
,
2001
, “
Friction Studies of Hydrogel Contact Lenses Using AFM: Non-Crosslinked Polymers of Low Friction at the Surface
,”
Biomaterials
,
22
(
24
), pp.
3285
3294
.
7.
Ratner
,
B.
, and
Hoffman
,
A.
,
1976
, “
Synthetic Hydrogels for Biomedical Applications
,”
Hydrogels Med. Relat. Appl.
,
31
.
8.
Pan
,
Y. S.
,
Xiong
,
D. S.
, and
Ma
,
R. Y.
,
2007
, “
A Study on the Friction Properties of Poly(Vinyl Alcohol) Hydrogel as Articular Cartilage Against Titanium Alloy
,”
Wear
,
262
(
7–8
), pp.
1021
1025
.
9.
Gong
,
J. P.
,
2006
, “
Friction and Lubrication of Hydrogels—Its Richness and Complexity
,”
Soft Matter
,
2
(
7
), pp.
544
552
.
10.
Osada
,
Y.
, and
Gong
,
J. P.
,
1998
, “
Soft and Wet Materials: Polymer Gels
,”
Adv. Mater.
,
10
(
11
), pp.
827
837
.
11.
Gong
,
J.
,
Higa
,
M.
,
Iwasaki
,
Y.
,
Katsuyama
,
Y.
, and
Osada
,
Y.
,
1997
, “
Friction of Gels
,”
J. Phys. Chem. B
,
101
(
28
), pp.
5487
5489
.
12.
Hoffman
,
A. S.
,
2012
, “
Hydrogels for Biomedical Applications
,”
Adv. Drug Delivery Rev.
,
64
, pp.
18
23
.
13.
Bavaresco
,
V. P.
,
Zavaglia
,
C. A. C.
,
Reis
,
M. C.
, and
Gomes
,
J. R.
,
2008
, “
Study on the Tribological Properties of pHEMA Hydrogels for Use in Artificial Articular Cartilage
,”
Wear
,
265
, pp.
269
277
.
14.
Halperin
,
A.
,
Tirrell
,
M.
, and
Lodge
,
T. P.
,
1992
, “
Tethered Chains in Polymer Microstructures
,”
Macromol. Synth. Order Adv. Prop.
,
100
(
1
), pp.
31
71
.
15.
Sun
,
J.
,
Graeter
,
S. V.
,
Yu
,
L.
,
Duan
,
S.
,
Spatz
,
J. P.
, and
Ding
,
J.
,
2008
, “
Technique of Surface Modification of a Cell-Adhesion-Resistant Hydrogel by a Cell-Adhesion-Available Inorganic Microarray
,”
Biomacromolecules
,
9
(
10
), pp.
2569
2572
.
16.
Ohsedo
,
Y.
,
Takashina
,
R.
,
Gong
,
J. P.
, and
Osada
,
Y.
,
2004
, “
Surface Friction of Hydrogels with Well-Defined Polyelectrolyte Brushes
,”
Langmuir
,
20
(
16
), pp.
6549
6555
.
17.
Ratner
,
B.
,
1986
, “
Hydrogel Surfaces
,” Hydrogels in Medicine and Pharmacy,
CRC Press
,
Boca Raton, FL
.
18.
Urueña
,
J. M.
,
Pitenis
,
A. A.
,
Nixon
,
R. M.
,
Schulze
,
K. D.
,
Angelini
,
T. E.
, and
Sawyer
,
W. G.
,
2015
, “
Mesh Size Control of Polymer Fluctuation Lubrication Mechanisms in Gemini Hydrogels
,”
Biotribology
,
1
(
352
), pp.
24
29
.
19.
Pitenis
,
A. A.
,
Urueña
,
J. M.
,
Schulze
,
K. D.
,
Nixon
,
R. M.
,
Dunn
,
A. C.
, and
Krick
,
B. A.
,
2014
, “
Polymer Fluctuation Lubrication in Hydrogel Gemini Interfaces
,”
Soft Matter
,
10
(
44
), pp.
8955
8962
.
20.
Beer
,
S.
,
Müser
,
M. H.
, and
de Beer
,
S.
,
2013
, “
Alternative Dissipation Mechanisms and the Effect of the Solvent in Friction Between Polymer Brushes on Rough Surfaces
,”
Soft Matter
,
9
(
30
), pp.
7234
7241
.
21.
Morgenthaler
,
S.
,
Zink
,
C.
, and
Spencer
,
N. D.
,
2008
, “
Surface-Chemical and -Morphological Gradients
,”
Soft Matter
,
4
(
3
), pp.
419
434
.
22.
Dunn
,
A. C.
,
Sawyer
,
W. G.
, and
Angelini
,
T. E.
,
2014
, “
Gemini Interfaces in Aqueous Lubrication With Hydrogels
,”
Tribol. Lett.
,
54
(
1
), pp.
59
66
.
23.
Urueña
,
J. M.
,
Pitenis
,
A. A.
,
Harris
,
K. L.
, and
Sawyer
,
W. G.
,
2015
, “
Evolution and Wear of Fluoropolymer Transfer Films
,”
Tribol. Lett.
,
57
(
9
).
24.
Schmitz
,
T. L.
,
Action
,
J. E.
,
Ziegert
,
J. C.
, and
Sawyer
,
W, G.
,
2005
, “
The Difficulty of Measuring Low Friction: Uncertainty Analysis for Friction Coefficient Measurements
,”
ASME J. Tribol.
,
127
(
3
), pp.
673
678
.
25.
Rubinstein
,
M.
, and
Colby
,
R. H.
,
2003
,
Polymer Physics
,
Oxford University Press
,
New York
.
26.
de Gennes
,
P. G.
,
1979
,
Scaling Concepts in Polymer Physics
,
Cornell University Press
,
Ithaca, NY/London
.
You do not currently have access to this content.