The mass transport behavior through nanoscale channels, greatly influenced by the structures and dynamics of nanoconfined water, plays an essential role in many biophysical processes. However, the dynamics of nanoconfined water under an external field and its effects are still not fully understood. Here, on the basis of molecular dynamics simulations, we theoretically show that the ionic current of [Bmim][PF6] through narrow pores in graphene membrane exhibits an ionic negative differential resistance effect—the ionic current decreases as the voltage increases over a certain threshold. This effect arises from the violation of traditional fluid dynamics as the assumption of continuity and homogeneity of fluids is no longer effective in ultrathin nanopores. The gradient of electric field around the atomic-thin layer produces a strong gradient force on the polarized water inside the nanopore. This dielectrophoretically compressed water leads to a hydrostatic force that repels ions from entering the nanopore. Our findings may advance the understanding of hydrostatic mechanism, which governs ion transport through nanopores.

1.
L.
Bocquet
, “
Nanofluidics coming of age
,”
Nat. Mater.
19
(
3
),
254
256
(
2020
).
2.
L.
Bocquet
and
E.
Charlaix
, “
Nanofluidics, from bulk to interfaces
,”
Chem. Soc. Rev.
39
(
3
),
1073
1095
(
2010
).
3.
N.
Kavokine
,
R. R.
Netz
, and
L.
Bocquet
, “
Fluids at the nanoscale: From continuum to subcontinuum transport
,”
Annu. Rev. Fluid. Mech.
53
(
1
),
377
410
(
2021
).
4.
J.
Feng
,
K.
Liu
,
M.
Graf
,
D.
Dumcenco
,
A.
Kis
,
M.
Di Ventra
, and
A.
Radenovic
, “
Observation of ionic Coulomb blockade in nanopores
,”
Nat. Mater.
15
(
8
),
850
855
(
2016
).
5.
N.
Kavokine
,
S.
Marbach
,
A.
Siria
, and
L.
Bocquet
, “
Ionic Coulomb blockade as a fractional Wien effect
,”
Nat. Nanotechnol.
14
(
6
),
573
578
(
2019
).
6.
Z.
Wan
,
Y.
Gao
,
X.
Chen
,
X. C.
Zeng
,
J. S.
Francisco
, and
C.
Zhu
, “
Anomalous water transport in narrow-diameter carbon nanotubes
,”
Proc. Natl. Acad. Sci. U. S. A.
119
(
39
),
e2211348119
(
2022
).
7.
Q.-L.
Zhang
,
R.-Y.
Yang
,
C.-L.
Wang
, and
J.
Hu
, “
Ultrafast active water pump driven by terahertz electric fields
,”
Phys. Rev. Fluids
7
(
11
),
114202
(
2022
).
8.
W.
Zhou
,
Y.
Guo
,
Z.
Zhang
,
W.
Guo
, and
H.
Qiu
, “
Field-induced hydration shell reorganization enables electro-osmotic flow in nanochannels
,”
Phys. Rev. Lett.
130
(
8
),
084001
(
2023
).
9.
M.
Xue
,
Z.
Hu
,
H.
Qiu
,
C.
Shen
,
W.
Guo
, and
Z.
Zhang
, “
An analog of Friedel oscillations in nanoconfined water
,”
Natl. Sci. Rev.
9
(
9
),
nwab214
(
2022
).
10.
H.
Jalali
,
E.
Lotfi
,
R.
Boya
, and
M.
Neek-Amal
, “
Abnormal dielectric constant of nanoconfined water between graphene layers in the presence of salt
,”
J. Phys. Chem. B
125
(
6
),
1604
1610
(
2021
).
11.
A.
Schlaich
,
E. W.
Knapp
, and
R. R.
Netz
, “
Water dielectric effects in planar confinement
,”
Phys. Rev. Lett.
117
(
4
),
048001
(
2016
).
12.
P.
Robin
,
T.
Emmerich
,
A.
Ismail
,
A.
Niguès
,
Y.
You
,
G.-H.
Nam
,
A.
Keerthi
,
A.
Siria
,
A. K.
Geim
,
B.
Radha
, and
L.
Bocquet
, “
Long-term memory and synapse-like dynamics in two-dimensional nanofluidic channels
,”
Science
379
(
6628
),
161
167
(
2023
).
13.
M. E.
Suk
and
N. R.
Aluru
, “
Ion transport in sub-5-nm graphene nanopores
,”
J. Chem. Phys.
140
(
8
),
084707
(
2014
).
14.
S.
Sahu
,
M.
Di Ventra
, and
M.
Zwolak
, “
Dehydration as a universal mechanism for ion selectivity in graphene and other atomically thin pores
,”
Nano Lett.
17
(
8
),
4719
4724
(
2017
).
15.
S.
Sahu
,
J.
Elenewski
,
C.
Rohmann
, and
M.
Zwolak
, “
Optimal transport and colossal ionic mechano-conductance in graphene crown ethers
,”
Sci. Adv.
5
(
7
),
eaaw5478
(
2019
).
16.
G.
Hu
,
M.
Mao
, and
S.
Ghosal
, “
Ion transport through a graphene nanopore
,”
Nanotechnology
23
(
39
),
395501
(
2012
).
17.
J.
Wilson
and
A.
Aksimentiev
, “
Water-compression gating of nanopore transport
,”
Phys. Rev. Lett.
120
(
26
),
268101
(
2018
).
18.
J.
Feng
,
K.
Liu
,
R. D.
Bulushev
,
S.
Khlybov
,
D.
Dumcenco
,
A.
Kis
, and
A.
Radenovic
, “
Identification of single nucleotides in MoS2 nanopores
,”
Nat. Nanotechnol.
10
(
12
),
1070
1076
(
2015
).
19.
M.
Shankla
and
A.
Aksimentiev
, “
Molecular transport across the ionic liquid–aqueous electrolyte interface in a MoS2 nanopore
,”
ACS Appl. Mater. Interfaces
12
(
23
),
26624
26634
(
2020
).
20.
M. J.
Abraham
,
T.
Murtola
,
R.
Schulz
,
S.
Páll
,
J. C.
Smith
,
B.
Hess
, and
E.
Lindahl
, “
GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers
,”
SoftwareX
1–2
,
19
25
(
2015
).
21.
W.
Humphrey
,
A.
Dalke
, and
K.
Schulten
, “
VMD: Visual molecular dynamics
,”
J. Mol. Graphics
14
(
1
),
33
38
(
1996
).
22.
W. L.
Jorgensen
,
J.
Chandrasekhar
,
J. D.
Madura
,
R. W.
Impey
, and
M. L.
Klein
, “
Comparison of simple potential functions for simulating liquid water
,”
J. Chem. Phys.
79
(
2
),
926
935
(
1983
).
23.
G.
Hummer
,
J. C.
Rasaiah
, and
J. P.
Noworyta
, “
Water conduction through the hydrophobic channel of a carbon nanotube
,”
Nature
414
(
6860
),
188
190
(
2001
).
24.
T. I.
Morrow
and
E. J.
Maginn
, “
Molecular dynamics study of the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate
,”
J. Phys. Chem. B
106
(
49
),
12807
12813
(
2002
).
25.
G.
Bussi
,
D.
Donadio
, and
M.
Parrinello
, “
Canonical sampling through velocity rescaling
,”
J. Chem. Phys.
126
(
1
),
014101
(
2007
).
26.
M.
Parrinello
and
A.
Rahman
, “
Polymorphic transitions in single crystals: A new molecular dynamics method
,”
J. Appl. Phys.
52
(
12
),
7182
7190
(
1981
).
27.
T.
Darden
,
D.
York
, and
L.
Pedersen
, “
Particle mesh Ewald: An N · log(N) method for Ewald sums in large systems
,”
J. Chem. Phys.
98
(
12
),
10089
10092
(
1993
).
28.
S.
Miyamoto
and
P. A.
Kollman
, “
Settle: An analytical version of the SHAKE and RATTLE algorithm for rigid water models
,”
J. Comput. Chem.
13
(
8
),
952
962
(
1992
).
29.
B.
Hess
,
H.
Bekker
,
H. J. C.
Berendsen
, and
J. G. E. M.
Fraaije
, “
LINCS: A linear constraint solver for molecular simulations
,”
J. Comput. Chem.
18
(
12
),
1463
1472
(
1997
).
30.
R. J.
Gowers
,
M.
Linke
,
J.
Barnoud
,
T. J. E.
Reddy
,
M. N.
Melo
,
S. L.
Seyler
,
D. L.
Dotson
,
J.
Domanski
,
S.
Buchoux
,
I. M.
Kenney
, and
O.
Beckstein
, “
MDAnalysis: A Python package for the rapid analysis of molecular dynamics simulations
,” in
Proceedings of the 15th Python in Science Conference
, edited by
S.
Benthall
and
S.
Rostrup
(
SciPy
,
Austin, TX
,
2016
), pp.
98
105
.
31.
N.
Michaud-Agrawal
,
E. J.
Denning
,
T. B.
Woolf
, and
O.
Beckstein
, “
MDAnalysis: A toolkit for the analysis of molecular dynamics simulations
,”
J. Comput. Chem.
32
(
10
),
2319
2327
(
2011
).
32.
J. S.
Hub
,
B. L.
de Groot
, and
D.
van der Spoel
, “
g_wham—A free weighted histogram analysis implementation including robust error and autocorrelation estimates
,”
J. Chem. Theory Comput.
6
(
12
),
3713
3720
(
2010
).
33.
C.
Di Natale
,
Introduction to Electronic Devices
(
Springer Nature Switzerland
,
Cham
,
2023
).
34.
W.
Zhu
,
Y.
Huang
,
C.
Zhu
,
H.-H.
Wu
,
L.
Wang
,
J.
Bai
,
J.
Yang
,
J. S.
Francisco
,
J.
Zhao
,
L.-F.
Yuan
, and
X. C.
Zeng
, “
Room temperature electrofreezing of water yields a missing dense ice phase in the phase diagram
,”
Nat. Commun.
10
(
1
),
1925
(
2019
).
35.
S.
Sahu
and
M.
Zwolak
, “
Colloquium: Ionic phenomena in nanoscale pores through 2D materials
,”
Rev. Mod. Phys.
91
(
2
),
021004
(
2019
).
36.
D. J.
Evans
and
B. L.
Holian
, “
The Nose–Hoover thermostat
,”
J. Chem. Phys.
83
(
8
),
4069
4074
(
1985
).
37.
B.
Roux
, “
The calculation of the potential of mean force using computer simulations
,”
Comput. Phys. Commun.
91
(
1–3
),
275
282
(
1995
).
38.
L.
Luo
,
D. A.
Holden
,
W.-J.
Lan
, and
H. S.
White
, “
Tunable negative differential electrolyte resistance in a conical nanopore in glass
,”
ACS Nano
6
(
7
),
6507
6514
(
2012
).
39.
L.-Q.
Gu
,
S.
Cheley
, and
H.
Bayley
, “
Electroosmotic enhancement of the binding of a neutral molecule to a transmembrane pore
,”
Proc. Natl. Acad. Sci. U. S. A.
100
(
26
),
15498
15503
(
2003
).
40.
S.
van Dorp
,
U. F.
Keyser
,
N. H.
Dekker
,
C.
Dekker
, and
S. G.
Lemay
, “
Origin of the electrophoretic force on DNA in solid-state nanopores
,”
Nat. Phys.
5
(
5
),
347
351
(
2009
).
41.
M.
Mao
,
J. D.
Sherwood
, and
S.
Ghosal
, “
Electro-osmotic flow through a nanopore
,”
J. Fluid Mech.
749
,
167
183
(
2014
).
42.
W.
Brown
,
M.
Kvetny
,
R.
Yang
, and
G.
Wang
, “
Higher ion selectivity with lower energy usage promoted by electro-osmotic flow in the transport through conical nanopores
,”
J. Phys. Chem. C
125
(
6
),
3269
3276
(
2021
).
43.
B.
Luan
and
A.
Aksimentiev
, “
Electro-osmotic screening of the DNA charge in a nanopore
,”
Phys. Rev. E
78
(
2
),
021912
(
2008
).
44.
W. L.
Jorgensen
and
C.
Jenson
, “
Temperature dependence of TIP3P, SPC, and TIP4P water from NPT Monte Carlo simulations: Seeking temperatures of maximum density
,”
J. Comput. Chem.
19
(
10
),
1179
1186
(
1998
).
You do not currently have access to this content.