Understanding polymer transport in nanopores is crucial for optimizing heterogeneously catalyzed processes in polymer upcycling and fabricating high-performance nanocomposite films and membranes. Although confined polymer dynamics have been extensively studied, the behavior of polyethylene (PE)—the most widely used commodity polymer—in pores smaller than 20 nm remains largely unexplored. We investigate the effects of extreme nanoconfinement on PE transport using capillary rise infiltration in silica nanoparticle packings with average pore radii ranging from ∼1 to ∼9 nm. Using in situ ellipsometry and the Lucas–Washburn model, we discover a previously unknown inverse relationship between effective viscosity (ηeff) and average pore radius (Rpore). Additonally, we determine that PE transport under these extreme conditions is primarily governed by physical confinement, rather than pore surface chemistry. We refine an existing theory to provide a generalized formalism to describe the polymer transport dynamics over a wide range of pore radii (from 1 nm and larger). Our results offer valuable insights for optimizing catalyst supports in polymer upcycling and improving infiltration processes for nanocomposite fabrication.

1.
A.
Bin Jumah
,
M.
Malekshahian
,
A. A.
Tedstone
, and
A. A.
Garforth
, “
Kinetic modeling of hydrocracking of low-density polyethylene in a batch reactor
,”
ACS Sustainable Chem. Eng.
9
(
49
),
16757
16769
(
2021
).
2.
A.
Tennakoon
,
X.
Wu
,
A. L.
Paterson
,
S.
Patnaik
,
Y.
Pei
et al, “
Catalytic upcycling of high-density polyethylene via a processive mechanism
,”
Nat. Catal.
3
(
11
),
893
901
(
2020
).
3.
E. G.
Fuentes-Ordóñez
,
J. A.
Salbidegoitia
,
M. P.
González-Marcos
, and
J. R.
González-Velasco
, “
Transport phenomena in catalytic hydrocracking of polystyrene in solution
,”
Ind. Eng. Chem. Res.
52
(
42
),
14798
14807
(
2013
).
4.
Q.
Kang
,
M.
Chu
,
P.
Xu
,
X.
Wang
,
S.
Wang
,
M.
Cao
,
O.
Ivasenko
,
T.-K.
Sham
,
Q.
Zhang
,
Q.
Sun
, and
J.
Chen
, “
Entropy confinement promotes hydrogenolysis activity for polyethylene upcycling
,”
Angew. Chem., Int. Ed.
62
,
e202313174
(
2023
).
5.
R. B.
Venkatesh
,
N.
Manohar
,
Y.
Qiang
,
H.
Wang
,
H. H.
Tran
,
B. Q.
Kim
,
A.
Neuman
,
T.
Ren
,
Z.
Fakhraai
,
R. A.
Riggleman
,
K. J.
Stebe
,
K.
Turner
, and
D.
Lee
, “
Polymer-infiltrated nanoparticle films using capillarity-based techniques: Toward multifunctional coatings and membranes
,”
Annu. Rev. Chem. Biomol. Eng.
12
(
1
),
411
437
(
2021
).
6.
J. L.
Hor
,
H.
Wang
,
Z.
Fakhraai
, and
D.
Lee
, “
Effect of physical nanoconfinement on the viscosity of unentangled polymers during capillary rise infiltration
,”
Macromolecules
51
(
14
),
5069
5078
(
2018
).
7.
J. L.
Hor
,
Y.
Jiang
,
D. J.
Ring
,
R. A.
Riggleman
,
K. T.
Turner
, and
D.
Lee
, “
Nanoporous polymer-infiltrated nanoparticle films with uniform or graded porosity via undersaturated capillary rise infiltration
,”
ACS Nano
11
(
3
),
3229
3236
(
2017
).
8.
B. Q.
Kim
,
M.
Füredi
,
R. B.
Venkatesh
,
S.
Guldin
, and
D.
Lee
, “
Water-induced separation of polymers from high nanoparticle-content nanocomposite films
,”
Small
19
,
2302676
(
2023
).
9.
Y.
Qiang
,
K. T.
Turner
, and
D.
Lee
, “
Role of polymer-nanoparticle interactions on the fracture toughness of polymer-infiltrated nanoparticle films
,”
Macromolecules
56
(
1
),
122
135
(
2023
).
10.
H.
Wang
,
Y.
Qiang
,
A. A.
Shamsabadi
,
P.
Mazumder
,
K. T.
Turner
,
D.
Lee
, and
Z.
Fakhraai
, “
Thermal degradation of polystyrene under extreme nanoconfinement
,”
ACS Macro Lett.
8
(
11
),
1413
1418
(
2019
).
11.
C. H.
Tu
,
M.
Steinhart
,
R.
Berger
,
M.
Kappl
,
H. J.
Butt
, and
G.
Floudas
, “
When crystals flow
,”
Sci. Adv.
9
(
19
),
eadg8865
(
2023
).
12.
R.
Kimmich
,
N.
Fatkullin
,
C.
Mattea
, and
E.
Fischer
, “
Polymer chain dynamics under nanoscopic confinements
,”
Magn. Reson. Imaging
23
(
2
),
191
196
(
2005
).
13.
W. S.
Tung
,
R. J.
Composto
,
R. A.
Riggleman
, and
K. I.
Winey
, “
Local polymer dynamics and diffusion in cylindrical nanoconfinement
,”
Macromolecules
48
(
7
),
2324
2332
(
2015
).
14.
D. B.
Zax
,
D. K.
Yang
,
R. A.
Santos
,
H.
Hegemann
,
E. P.
Giannelis
, and
E.
Manias
, “
Dynamical heterogeneity in nanoconfined poly(styrene) chains
,”
J. Chem. Phys.
112
(
6
),
2945
2951
(
2000
).
15.
K.
Shin
,
S.
Obukhov
,
J.-T.
Chen
,
J.
Huh
,
Y.
Hwang
,
S.
Mok
,
P.
Dobriyal
,
P.
Thiyagarajan
, and
T. P.
Russell
, “
Enhanced mobility of confined polymers
,”
Nat. Mater.
6
(
12
),
961
965
(
2007
).
16.
F.
Lange
,
P.
Judeinstein
,
C.
Franz
,
B.
Hartmann-Azanza
,
S.
Ok
,
M.
Steinhart
, and
K.
Saalwächter
, “
Large-scale diffusion of entangled polymers along nanochannels
,”
ACS Macro Lett.
4
(
5
),
561
565
(
2015
).
17.
E. K.
Lin
,
R.
Kolb
,
S. K.
Satija
, and
W. L.
Wu
, “
Reduced polymer mobility near the polymer/solid interface as measured by neutron reflectivity
,”
Macromolecules
32
(
11
),
3753
3757
(
1999
).
18.
S.
Gam
,
J. S.
Meth
,
S. G.
Zane
,
C.
Chi
,
B. A.
Wood
,
M. E.
Seitz
,
K. I.
Winey
,
N.
Clarke
, and
R. J.
Composto
, “
Macromolecular diffusion in a crowded polymer nanocomposite
,”
Macromolecules
44
(
9
),
3494
3501
(
2011
).
19.
C.-C.
Lin
,
S.
Gam
,
J. S.
Meth
,
N.
Clarke
,
K. I.
Winey
, and
R. J.
Composto
, “
Do attractive polymer-nanoparticle interactions retard polymer diffusion in nanocomposites?
,”
Macromolecules
46
(
11
),
4502
4509
(
2013
).
20.
R. B.
Venkatesh
and
D.
Lee
, “
Conflicting effects of extreme nanoconfinement on the translational and segmental motion of entangled polymers
,”
Macromolecules
55
(
11
),
4492
4501
(
2022
).
21.
Y.
Yao
,
H. J.
Butt
,
G.
Floudas
,
J.
Zhou
, and
M.
Doi
, “
Theory on capillary filling of polymer melts in nanopores
,”
Macromol. Rapid Commun.
39
(
14
),
1800087
(
2018
).
22.
B. D.
Vogt
, “
Mechanical and viscoelastic properties of confined amorphous polymers
,”
J. Polym. Sci., Part B: Polym. Phys.
56
(
1
),
9
30
(
2018
).
23.
S.
Jin
and
G. B.
McKenna
, “
Effect of nanoconfinement on polymer chain dynamics
,”
Macromolecules
53
(
22
),
10212
10216
(
2020
).
24.
F.
Tian
,
S.
Zhang
,
M.
Zhai
,
J.
Sui
,
X.
Lan
, and
J.
Gao
, “
Thermal properties of nano-sized polyethylene glycol confined in silica gels for latent heat storage
,”
Thermochim. Acta
655
,
211
218
(
2017
).
25.
C.-H.
Tu
,
M.
Steinhart
,
H.-J.
Butt
, and
G.
Floudas
, “
In situ monitoring of the imbibition of poly(n-butyl methacrylates) in nanoporous alumina by dielectric spectroscopy
,”
Macromolecules
52
(
21
),
8167
8176
(
2019
).
26.
J. L.
Hor
,
H.
Wang
,
Z.
Fakhraai
, and
D.
Lee
, “
Effects of polymer-nanoparticle interactions on the viscosity of unentangled polymers under extreme nanoconfinement during capillary rise infiltration
,”
Soft Matter
14
(
13
),
2438
2446
(
2018
).
27.
Y. R.
Huang
,
Y.
Jiang
,
J. L.
Hor
,
R.
Gupta
,
L.
Zhang
,
K. J.
Stebe
,
G.
Feng
,
K. T.
Turner
, and
D.
Lee
, “
Polymer nanocomposite films with extremely high nanoparticle loadings via capillary rise infiltration (CaRI)
,”
Nanoscale
7
(
2
),
798
805
(
2015
).
28.
Y.
Rouault
and
S.
Assouline
, “
A probabilistic approach towards modeling the relationships between particle and pore size distributions: The multicomponent packed sphere case
,”
Powder Technol.
96
(
1
),
33
41
(
1998
).
29.
M. M.
Roozbahani
,
R.
Borela
, and
J. D.
Frost
, “
Pore size distribution in granular material microstructure
,”
Materials
10
(
11
),
1237
(
2017
).
30.
H.
Pertoft
,
T. C.
Laurent
,
T.
Låås
, and
L.
Kågedal
, “
Density gradients prepared from colloidal silica particles coated by polyvinylpyrrolidone (Percoll)
,”
Anal. Biochem.
88
(
1
),
271
282
(
1978
).
31.
T.
Ren
,
R.
Huang
,
J.
Gorte
, and
D.
Lee
, “
Modulating interactions between molten polystyrene and porous solids using atomic layer deposition
,”
Langmuir
37
(
49
),
14520
14526
(
2021
).
32.
W.
Gardner
, “
Note on the dynamics of capillary flow
,”
Phys. Rev.
18
(
3
),
206
209
(
1921
).
33.
H. W.
Starkweather
, “
The surface tension of polyethylene
,”
Polym. Eng. Sci.
5
(
1
),
5
6
(
1965
).
34.
T.
Ren
,
C. Y.
Wang
,
R.
Huang
,
C.
Deng
,
Y.
Xu
,
A.
Majumder
,
J.
Ra
,
K.
Shen
,
J. M.
Vohs
,
J. J.
de Pablo
,
R. J.
Gorte
, and
D.
Lee
, “
Understanding polymer-porous solid interactions based on small gas molecule adsorption behavior
,”
Chem. Eng. J.
473
,
145220
(
2023
).
35.
M.
Rubinstein
and
R. H.
Colby
,
Polymer Physics
(
Oxford University Press
, 2003).
36.
Y.
Yao
,
S.
Alexandris
,
F.
Henrich
,
G.
Auernhammer
,
M.
Steinhart
,
H.-J.
Butt
, and
G.
Floudas
, “
Complex dynamics of capillary imbibition of poly(ethylene oxide) melts in nanoporous alumina
,”
J. Chem. Phys.
146
(
20
),
203320
(
2017
).
37.
X.
Lyu
,
M.
Meirow
,
X.
Wu
,
X.
Zhou
,
Y.
Liu
,
W.
Huang
,
T.
Li
, and
B.
Lee
, “
Molecular-weight-dependent infiltration and adsorption of polymers into nanochannels
,”
ACS Appl. Mater. Interfaces
15
(
22
),
27369
27379
(
2023
).
38.
F.
Brochard
and
P. G.
de Gennes
, “
Dynamics of confined polymer chains
,”
J. Chem. Phys.
67
,
52
56
(
1977
).
39.
L.
Dai
and
P. S.
Doyle
, “
Comparisons of a polymer in confinement versus applied force
,”
Macromolecules
46
(
15
),
6336
6344
(
2013
).

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