Supplementary information
Wet-spinning assembly of continuous, neat, and macroscopic graphene fibers
Huai-Ping Cong, Xiao-Chen Ren, Ping Wang, Shu-Hong Yu*
Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at
Microscale, Department of Chemistry, the National Synchrotron Radiation Laboratory,
University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
Figure S1 | AFM image of the initial GO dispersion on mica wafer. (a) and the corresponding
height profile (b).
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Figure S2 | Wet-spinning set-up. Photograph of the wet-spinning set-up with a double-jet pump
at a speed of 25 mL/min.
Figure S3 | Flexibility of GO fibers. Photographs of (a) the spring-like GO fiber carried with a
tweezers along the axial direction; (b) the knitted pattern of “USTC” in a cotton textile using a
needle with the GO fibers as the threads.
S2
Figure S4 | Tunable diameters of macroscopic GO fibers. (a) Photographs of GO fibers by the
wet-spinning technique using nozzles with different sizes of 0.11, 0.26, 0.41, and 0.6 mm,
respectively (from left to right). SEM images of GO fibers by spinning of GO dopes with
different concentrations: (b) 5; (c) 8; (d) 10; (e) 22 mg/mL.
Figure S5 | Microstructures of graphene fibers. SEM images with different magnifications of
the graphene fiber prepared by chemical reduction of GO fiber.
S3
D band
G band
Intensity
(a) GO fiber
(b) GO-PNIPAM fiber
2D band
(c)
Graphene fiber
(d) Graphene-PNIPAM fiber
500
1000
1500
2000
2500
3000
3500
Wavenumber (cm-1)
Figure S6 | Raman spectra of the single fiber. (a) GO. (b) GO/PNIPAM. (c) Graphene. (d)
Graphene/PNIPAM.
(b)
(a)
120000
GO powder
Counts / s
Intensity (a.u.)
40
GO fiber
20
O1s
(19.86 at.%)
80000
N1s
(2.94 at.%)
40000
0
4000
as(-CH3)
as(-CH2)
3000
s(-CH2)
(C-N)
2000
Wavenumber (cm-1)
C1s
(77.20 at.%)
(C-C)
1000
0
600
500
400
300
200
Binding Energy (eV)
Figure S7 | Analyses of components of the GO fiber. (a) FT-IR spectra of GO powder and the
single GO fiber. (b) XPS spectrum of the dry GO fibers.
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Figure S8 | SEM images of the GO-epoxy resin composite fiber. (a) Outer surface of the fiber.
(b) A broken fiber. (c) Different magnifications of the cross-section of the broken part in (b)
marked with the white rectangle.
(a)
600
(b)
100
Tensile Stress (MPa)
Intensity (a.u.)
500
400
300
200
100
0
10
20
30
2(degree)
40
50
80
60
40
20
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Strain (%)
Figure S9 | XRD pattern (a) and mechanic property (b) of the GO-epoxy resin composite fibers.
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Figure S10 | SEM images. (a, b) GO/PNIPAM fiber by wet spinning GO/PNIPAM dope with
the weight ratio of 1:1 and GO concentration of 5 mg/mL. (c, d) graphene/PNIPAM fiber
prepared by chemical reduction of GO/PNIPAM fiber.
(b) GO-PNIPAM fiber
*
as(-CH2) s(-CH2)
Intensity
*
Amide I
Amide II
s(-CH3)
*
1800
*
(-NC)
as(-CH3)
(a) GO fiber
(-COOH)
(-CC)
*
*
*
(-C=O)
(-COO-)
1600
1400
*
(-CO)
1200
Wavenumber (cm-1)
Figure S11 | FT-IR spectra. (a) A single GO fiber. (b) A single GO/PNIPAM fiber by wet
spinning GO/PNIPAM composite dope with the weight ratio of 1:1.
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Figure S12 | Structure and mechanic property of the GO-MWCNTs composite fibers. (a, b)
SEM images of the outer surface and cross-section of GO-MWCNTs fibers with the weight ratio
of GO and MWCNTs of 2:1. (c) Typical strain-stress curves of the single fibers with different
weight ratios.
S7