High-performance and small-sized heat exchangers have been demanded due to the miniaturization and higher output of electronic devices, lasers, and energy harvesting/storage systems. Graphene nanosheet suspension has attracted attention as a next-generation nanofluid because of its high thermal conductivity and low pressure drop, while being dispersed stably without any additives. Graphene-based nanofluids have been mostly investigated using graphene oxide, and there are a few studies on pure graphene because of the limitation in mass production and stabilization at high concentrations of graphene. In this study, we prepared a 10 wt. % high-concentration few-layer graphene suspension by pulverizing graphite particles. Scanning electron microscopy, atomic force microscopy, and Raman spectra confirmed the few-layer graphene is formed in the suspension. The thermal conductivity of the suspension increased with concentration and suddenly jumped at a specific concentration. Furthermore, a significant improvement in thermal conductivity of >40% compared to base liquid was confirmed at 10 wt. % graphene content. A similar trend was observed for electrical resistance; 10 wt. % graphene suspension showed 62% lower resistance than that of 1 wt. %. These results suggest the percolation of graphene in a liquid, which has not been observed for graphene-based materials in previous research.
REFERENCES
1.
M. G.
Khan
and
A.
Fartaj
, “
A review on microchannel heat exchangers and potential applications
,” Int. J. Energy Res.
35
, 553
–582
(2011
).2.
H. A.
Mohammed
,
G.
Bhaskaran
,
N. H.
Shuaib
, and
R.
Saidur
, “
Heat transfer and fluid flow characteristics in microchannels heat exchanger using nanofluids: A review
,” Renewable Sustainable Energy Rev.
15
, 1502
–1512
(2011
).3.
S.
Simpson
,
A.
Schelfhout
,
C.
Golden
, and
S.
Vafaei
, “
Nanofluid thermal conductivity and effective parameters
,” Appl. Sci.
9
, 87
(2018
).4.
C.
Kleinstreuer
and
Y.
Feng
, “
Experimental and theoretical studies of nanofluid thermal conductivity enhancement: A review
,” Nanoscale Res. Lett.
6
, 229
(2011
).5.
M. M.
Tawfik
, “
Experimental studies of nanofluid thermal conductivity enhancement and applications: A review
,” Renewable Sustainable Energy Rev.
75
, 1239
–1253
(2017
).6.
S. P.
Jang
and
S. U. S.
Choi
, “
Role of Brownian motion in the enhanced thermal conductivity of nanofluids
,” Appl. Phys. Lett.
84
, 4316
–4318
(2004
).7.
F.
Yang
,
Z.
Zhang
,
L.
Xu
,
Z.
Liu
,
P.
Jin
,
P.
Zhuang
,
M.
Lei
,
J.
Liu
,
J.-H.
Jiang
,
X.
Ouyang
,
F.
Marchesoni
, and
J.
Huang
, “
Controlling mass and energy diffusion with metamaterials
,” Rev. Mod. Phys.
96
, 015002
(2024
).8.
M.
Awais
,
N.
Ullah
,
J.
Ahmad
,
F.
Sikandar
,
M. M.
Ehsan
,
S.
Salehin
, and
A. A.
Bhuiyan
, “
Heat transfer and pressure drop performance of Nanofluid: A state-of-the-art review
,” Int. J. Thermofluids
9
, 100065
(2021
).9.
J. M.
Yin
,
C. W.
Bullard
, and
P. S.
Hrnjak
, “
Single-phase pressure drop measurements in a microchannel heat exchanger heat
,” Transfer Eng.
23
, 3
–12
(2002
).10.
V. N.
Manzhai
,
Y. R.
Nasibullina
,
A. S.
Kuchevskaya
, and
A. G.
Filimoshkin
, “
Physico-chemical concept of drag reduction nature in dilute polymer solutions (the Toms effect)
,” Chem. Eng. Process.
80
, 38
–42
(2014
).11.
J. L.
Lumley
, “
Drag reduction in turbulent flow by polymer additives
,” J. Polym. Sci. Macromol. Rev.
7
, 263
–290
(1973
).12.
J. L.
Zakin
,
B.
Lu
, and
H. W.
Bewersdorff
, “
Surfactant drag reduction
,” Rev. Chem. Eng.
14
, 253
–320
(1998
).13.
H.
Cui
and
J. R.
Grace
, “
Flow of pulp fibre suspension and slurries: A review
,” Int. J. Multiphase Flow
33
, 921
–934
(2007
).14.
F.-C.
Li
,
Y.
Kawaguchi
, and
K.
Hishida
, “
Investigation on the characteristics of turbulence transport for momentum and heat in a drag-reducing surfactant solution flow
,” Phys. Fluids
16
, 3281
(2004
).15.
Z.
Zhang
,
L.
Xu
,
T.
Qu
,
M.
Lei
,
Z.-K.
Lin
,
X.
Ouyang
,
J.-H.
Jiang
, and
J.
Huang
, “
Diffusion metamaterials
,” Nat. Rev. Phys.
5
, 218
–235
(2023
).16.
A. K.
Geim
, “
Graphene: Status and prospects
,” Science
324
, 1530
–1534
(2009
).17.
A. A.
Balandin
, “
Thermal properties of graphene and nanostructured carbon materials
,” Nat. Mater.
10
, 569
–581
(2011
).18.
K.
Watanabe
and
S.
Ogata
, “
Drag reduction of aqueous suspensions of fine solid matter in pipe flows
,” AlChE J.
67
(6
), e17241
(2021
).19.
Z.
Xu
and
C.
Gao
, “
Graphene in macroscopic order: Liquid crystals and wet-spun fibers
,” Acc. Chem. Res.
47
, 1267
–1276
(2014
).20.
C.
Vallés
,
R. J.
Young
,
D. J.
Lomax
, and
I. A.
Kinloch
, “
The rheological behaviour of concentrated dispersions of graphene oxide
,” J. Mater. Sci.
49
, 6311
–6320
(2014
).21.
K. S.
Novoselov
,
A. K.
Geim
,
S. V.
Morozov
,
D.
Jiang
,
Y.
Zhang
,
S. V.
Dubonos
,
I. V.
Grigorieva
, and
A. A.
Firsov
, “
Electric field in atomically thin carbon films
,” Science
306
, 666
–669
(2004
).22.
E.
Sadeghinezhad
,
M.
Mehrali
,
R.
Saidur
,
M.
Mehrali
,
S.
Tahan Latibari
,
A. R.
Akhiani
, and
H. S. C.
Metselaar
, “
A comprehensive review on graphene nanofluids: Recent research, development and applications
,” Energy Convers. Manage.
111
, 466
–487
(2016
).23.
L.
Dong
,
Z.
Chen
,
X.
Zhao
,
J.
Ma
,
S.
Lin
,
M.
Li
,
Y.
Bao
,
L.
Chu
,
K.
Leng
,
H.
Lu
, and
K. P.
Loh
, “
A non-dispersion strategy for large-scale production of ultra-high concentration graphene slurries in water
,” Nat. Commun.
9
(9
), 76
(2018
).24.
M.
Kole
and
T. K.
Dey
, “
Investigation of thermal conductivity, viscosity, and electrical conductivity of graphene based nanofluids
,” J. Appl. Phys.
113
, 084307
(2013
).25.
M.
Mehrali
,
E.
Sadeghinezhad
,
S. T.
Latibari
,
S. N.
Kazi
,
M.
Mehrali
,
M. N. B. M.
Zubir
, and
H. S. C.
Metselaar
, “
Investigation of thermal conductivity and rheological properties of nanofluids containing graphene nanoplatelets
,” Nanoscale Res. Lett
9
, 15
(2014
).26.
M.
Sandhya
,
D.
Ramasamy
,
K.
Sudhakar
,
K.
Kadirgama
, and
W. S. W.
Harun
, “
Ultrasonication an intensifying tool for preparation of stable nanofluids and study the time influence on distinct properties of graphene nanofluids—A systematic overview
,” Ultrason. Sonochem.
73
, 105479
(2021
).27.
H.
Ma
,
Z.
Shen
,
M.
Yi
,
S.
Ben
,
S.
Liang
,
L.
Liu
,
Y.
Zhang
,
X.
Zhang
, and
S.
Ma
, “
Direct exfoliation of graphite in water with addition of ammonia solution
,” J. Colloid Interface Sci.
503
, 68
–75
(2017
).28.
D.
Graf
,
F.
Molitor
,
K.
Ensslin
,
C.
Stampfer
,
A.
Jungen
,
C.
Hierold
, and
L.
Wirtz
, “
Spatially resolved Raman spectroscopy of single- and few-layer graphene
,” Nano Lett.
7
, 238
–242
(2007
).29.
L. M.
Malard
,
M. A.
Pimenta
,
G.
Dresselhaus
, and
M. S.
Dresselhaus
, “
Raman spectroscopy in graphene
,” Phys. Rep.
473
, 51
–87
(2009
).30.
R.
Taherialekouhi
,
S.
Rasouli
, and
A.
Khosravi
, “
An experimental study on stability and thermal conductivity of water-graphene oxide/aluminum oxide nanoparticles as a cooling hybrid nanofluid
,” Int. J. Heat Mass Transfer
145
, 118751
(2019
).31.
M.
Zadkhast
,
D.
Toghraie
, and
A.
Karimipour
, “
Developing a new correlation to estimate the thermal conductivity of MWCNT-CuO/water hybrid nanofluid via an experimental investigation
,” J. Therm. Anal. Calorim.
129
, 859
–867
(2017
).32.
S.
Iranmanesh
,
M.
Mehrali
,
E.
Sadeghinezhad
,
B. C.
Ang
,
H. C.
Ong
, and
A.
Esmaeilzadeh
, “
Evaluation of viscosity and thermal conductivity of graphene nanoplatelets nanofluids through a combined experimental–statistical approach using respond surface methodology method
,” Int. Commun. Heat Mass Transfer
79
, 74
–80
(2016
).33.
R.
Sadri
,
M.
Hosseini
,
S. N.
Kazi
,
S.
Bagheri
,
A. H.
Abdelrazek
,
G.
Ahmadi
,
N.
Zubir
,
R.
Ahmad
, and
N. I. Z.
Abidin
, “
A facile, bio-based, novel approach for synthesis of covalently functionalized graphene nanoplatelet nano-coolants toward improved thermo-physical and heat transfer properties
,” J. Colloid Interface Sci.
509
, 140
–152
(2018
).34.
S.
Rostami
,
A. A.
Nadooshan
, and
A.
Raisi
, “
An experimental study on the thermal conductivity of new antifreeze containing copper oxide and graphene oxide nano-additives
,” Powder Technol.
345
, 658
–667
(2019
).35.
A. J.
Marsden
,
D. G.
Papageorgiou
,
C.
Vallés
,
A.
Liscio
,
V.
Palermo
,
M. A.
Bissett
,
R. J.
Young
, and
I. A.
Kinloch
, “
Electrical percolation in graphene-polymer composites
,” 2D Mater.
5
, 032003
(2018
).36.
G.
Reina
,
N. D. Q.
Chau
,
Y.
Nishina
, and
A.
Bianco
, “
Graphene oxide size and oxidation degree govern its supramolecular interactions with siRNA
,” Nanoscale
10
, 5965
–5974
(2018
).37.
Y.
Xuan
and
Q.
Li
, “
Heat transfer enhancement of nanofluids
,” Int. J. Heat Fluid Flow
21
, 58
–64
(2000
).© 2024 Author(s). Published under an exclusive license by AIP Publishing.
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