âGeneral Approach to Individually Dispersed, Highly Soluble, and ...
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“General Approach to Individually Dispersed, Highly Soluble, and Conductive Graphene Nanosheets Functionalized by Nitrene Chemistry” Hongkun He and Chao Gao* MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou 310027, P. R. China. *Correspondence to [email protected] (C.G.) Synthesis of Azido-Terminated Poly(ethylene glycol) (Az-PEG). Under nitrogen atmosphere and magnetic stirring, DCC (7.08 g, 34.3 mmol), PEG-OH (Mn = 350, 750, or 1900 g/mol, 28.6 mmol), and DMAP (0.42 g, 3.4 mmol) were added into freshly distilled dichloromethane (100 mL). After the flask was immersed into an ice-water bath, Az-COOH (6.41 g, 34.3 mmol) was added. After 48 h, the reaction mixture was vacuum filtered and washed successively with 1M HCl solution, 1M NaOH solution, and deionized water. The organic phase was dried over anhydrous MgSO4 overnight, filtered, concentrated on a rotary evaporator, and dried under vacuum to give a yellow oil (Az-PEG350, AzPEG750)
or
white
solid
(Az-PEG1900).
1
H
NMR
(CDCl3,
δ,
ppm):
4.25
(m,
CH2OOCCH2CH2COOCH2), 3.64 (CH2 of PEG), 3.48 (t, CH2N3), 3.37 (s, OCH3), 2.68 (m, OOCCH2CH2COO). Synthesis of Azido-Terminated Long Alkyl Chain (Az-C16). Under nitrogen atmosphere and magnetic stirring, DCC (9.08 g, 44 mmol), Az-OH (6.96 g, 80 mmol), and DMAP (0.538 g, 4.4 mmol) were added into freshly distilled dichloromethane (100 mL). After the flask was immersed into an icewater bath, palmitic acid (10.24 g, 40 mmol) was added. After 30 h, the reaction mixture was vacuum filtered and washed successively with 1M HCl solution, 1M NaOH solution, and deionized water. The organic phase was concentrated on a rotary evaporator, and dried under vacuum to give a white solid. 1
H NMR (CDCl3, δ, ppm): 4.25 (t, CH2CH2N3), 3.47 (t, CH2N3), 2.35 (t, CH2COO), 1.64 (m,
CH2CH2COO), 1.25 (b, (CH2)12), 0.88 (t, CH3).
S1
Figure S1. AFM images of G-N-COOH (a), G-N-Br (b), G-N-OH (c), G-N-NH2 (d), G-N-PEG350 (e), and G-N-PEG750 (f). c
b
a
f
e
h= 2.79 nm
μm
μm
μm
d
h= 3.50 nm
h= 3.14 nm
h= 1.98 nm
h= 2.09 nm
μm
nm
S2
h= 5.10 nm
μm
Figure S2. SEM images of G-N-COOH (a,b), G-N-NH2 (c), G-N-PS (d), G-N-PEG1900 (e,f), G-NPEG750 (g,h), and G-N-PEG350 (i,j). The images in the right column (b, d, f, h, and j) are SEM sideview images of filtered films. a
b
50 μm
1 μm
d
c
20 μm
1 μm
e
f
2 μm
g
10 μm
h
2 μm
i
20 μm
j
5 μm
5 μm
S3
Figure S3. TEM images of G-N-OH (a,b), G-N-COOH (c,d), G-N-PS (e,f), G-N-C16 (g), G-N-Br-gPS (h,i), G-N-Br (j,k), G-N-NH2 (l,m), and G-N-NH2-g-C16 (n,o). . a
c
b
0.5 μm
d
0.5 μm
200 nm
f
e
200 nm
200 nm
g
200 nm
i
h
500 nm
200 nm
500 nm
S4
Figure S3 continued j
k
l
m
n
o
S5
Figure S4. The XRD (a) and EDS (b) results of G-N-COOH-Fe3O4, and photographs of G-N-COOHFe3O4 in DMF before and after being separated by an external magnetic field (c).
a
Intensity (a.u.)
(311)
C (111)
(220) (511) (440)
(400)
(422)
10
20
30
40
50
60
70
2 Theta (degree)
b
Intensity (a.u.)
C
Cu
Fe
O Fe
0
Cu
Fe
2
4
6 keV
c
S6
8
10
Figure S5. (a-c) TEM images of G-N-COOH-Fe3O4. (d-f) TEM images of G-N-OH-“Fe3O4” obtained in the control experiment using G-N-OH instead of G-N-COOH as the starting material.
a)
0.5 μm
d)
0.5 μm
b)
c)
100 nm
50 nm
f)
e)
50 nm
100 nm
S7
Figure S6. FTIR spectra of GO, f-GNs, and modified f-GNs. b
Intensity (a.u.)
Intensity (a.u.)
a
GO G-N-NH2
GO G-N-OH G-N-OH-g-PCL
4000
3000
2000
G-N-NH2-g-C16
4000
1000
3000
2000
1000 -1
Wavenumber (cm )
-1
Wavenumber (cm )
c
Intensity (a.u.)
Intensity (a.u.)
d
GO G-N-Br G-N-Br-g-PS G-N-PS
GO G-N-COOH
4000
3000
2000
4000
1000 -1
Intensity (a.u.)
GO G-N-PEG350 G-N-PEG750 G-N-PEG1900
3000
2500
2000
1500 -1
2500
2000
1500
Wavenumber (cm )
e
3500
3000
-1
Wavenumber (cm )
4000
3500
1000
500
Wavenumber (cm )
S8
1000
500
Figure S7. FTIR spectra of Az-PEG350 (a), Az-PEG750 (b), Az-PEG1900 (c), Az-C16 (d), Az-PS (e), and GPC curve of Az-PS (f). a
Intensity (a.u.)
Intensity (a.u.)
b
2104 -N3 4000
3500
3000
2500
2000
2104 -N3
1500
1000
4000
500
3500
3000
2500
2000
1500
1000
-1
-1
Wavenumber (cm )
Wavenumber (cm )
c
Intensity (a.u.)
Intensity (a.u.)
d
2106 -N3
4000
3500
3000
2500
2000
1500
1000
3500
500
2106 -N3
3000
2500
2000
1500
1000
-1
Wavenumber (cm )
-1
Wavenumber (cm )
e Intensity (a.u.)
f
4000
2104 -N3
3500
3000
2500
2000
1500
1000
3
500
10
-1
Wavenumber (cm )
4
10
Molecular Weight (g/mol)
S9
500
G-N-Br
G-N-NH2
G-N-COOH
G-N-OH
GO
S10
toluene
n-hexane
chloroform
methanol
ethanol
ethylene glycol
THF
acetone
NMP
DMF
DMSO
water
Figure S8. The photographs of GO, f-GNs, modified f-GNs and reduced GO in various solvents.
G-N-PEG1900
G-N-PEG750
G-N-PEG350
G-N-PS
G-N-C16
S11
toluene
n-hexane
chloroform
methanol
ethanol
ethylene glycol
THF
acetone
NMP
DMF
DMSO
water
Figure S8 continued
Reduced GO
G-N-Br-g-PS
G-N-NH2-g-C16 G-N-OH-g-PCL
S12
toluene
n-hexane
chloroform
methanol
ethanol
ethylene glycol
THF
acetone
NMP
DMF
DMSO
water
Figure S8 continued
“General Approach to Individually Dispersed, Highly Soluble, and Conductive Graphene Nanosheets Functionalized by Nitrene Chemistry” Hongkun He and Chao Gao* MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou 310027, P. R. China. *Correspondence to [email protected] (C.G.) Synthesis of Azido-Terminated Poly(ethylene glycol) (Az-PEG). Under nitrogen atmosphere and magnetic stirring, DCC (7.08 g, 34.3 mmol), PEG-OH (Mn = 350, 750, or 1900 g/mol, 28.6 mmol), and DMAP (0.42 g, 3.4 mmol) were added into freshly distilled dichloromethane (100 mL). After the flask was immersed into an ice-water bath, Az-COOH (6.41 g, 34.3 mmol) was added. After 48 h, the reaction mixture was vacuum filtered and washed successively with 1M HCl solution, 1M NaOH solution, and deionized water. The organic phase was dried over anhydrous MgSO4 overnight, filtered, concentrated on a rotary evaporator, and dried under vacuum to give a yellow oil (Az-PEG350, AzPEG750)
or
white
solid
(Az-PEG1900).
1
H
NMR
(CDCl3,
δ,
ppm):
4.25
(m,
CH2OOCCH2CH2COOCH2), 3.64 (CH2 of PEG), 3.48 (t, CH2N3), 3.37 (s, OCH3), 2.68 (m, OOCCH2CH2COO). Synthesis of Azido-Terminated Long Alkyl Chain (Az-C16). Under nitrogen atmosphere and magnetic stirring, DCC (9.08 g, 44 mmol), Az-OH (6.96 g, 80 mmol), and DMAP (0.538 g, 4.4 mmol) were added into freshly distilled dichloromethane (100 mL). After the flask was immersed into an icewater bath, palmitic acid (10.24 g, 40 mmol) was added. After 30 h, the reaction mixture was vacuum filtered and washed successively with 1M HCl solution, 1M NaOH solution, and deionized water. The organic phase was concentrated on a rotary evaporator, and dried under vacuum to give a white solid. 1
H NMR (CDCl3, δ, ppm): 4.25 (t, CH2CH2N3), 3.47 (t, CH2N3), 2.35 (t, CH2COO), 1.64 (m,
CH2CH2COO), 1.25 (b, (CH2)12), 0.88 (t, CH3).
S1
Figure S1. AFM images of G-N-COOH (a), G-N-Br (b), G-N-OH (c), G-N-NH2 (d), G-N-PEG350 (e), and G-N-PEG750 (f). c
b
a
f
e
h= 2.79 nm
μm
μm
μm
d
h= 3.50 nm
h= 3.14 nm
h= 1.98 nm
h= 2.09 nm
μm
nm
S2
h= 5.10 nm
μm
Figure S2. SEM images of G-N-COOH (a,b), G-N-NH2 (c), G-N-PS (d), G-N-PEG1900 (e,f), G-NPEG750 (g,h), and G-N-PEG350 (i,j). The images in the right column (b, d, f, h, and j) are SEM sideview images of filtered films. a
b
50 μm
1 μm
d
c
20 μm
1 μm
e
f
2 μm
g
10 μm
h
2 μm
i
20 μm
j
5 μm
5 μm
S3
Figure S3. TEM images of G-N-OH (a,b), G-N-COOH (c,d), G-N-PS (e,f), G-N-C16 (g), G-N-Br-gPS (h,i), G-N-Br (j,k), G-N-NH2 (l,m), and G-N-NH2-g-C16 (n,o). . a
c
b
0.5 μm
d
0.5 μm
200 nm
f
e
200 nm
200 nm
g
200 nm
i
h
500 nm
200 nm
500 nm
S4
Figure S3 continued j
k
l
m
n
o
S5
Figure S4. The XRD (a) and EDS (b) results of G-N-COOH-Fe3O4, and photographs of G-N-COOHFe3O4 in DMF before and after being separated by an external magnetic field (c).
a
Intensity (a.u.)
(311)
C (111)
(220) (511) (440)
(400)
(422)
10
20
30
40
50
60
70
2 Theta (degree)
b
Intensity (a.u.)
C
Cu
Fe
O Fe
0
Cu
Fe
2
4
6 keV
c
S6
8
10
Figure S5. (a-c) TEM images of G-N-COOH-Fe3O4. (d-f) TEM images of G-N-OH-“Fe3O4” obtained in the control experiment using G-N-OH instead of G-N-COOH as the starting material.
a)
0.5 μm
d)
0.5 μm
b)
c)
100 nm
50 nm
f)
e)
50 nm
100 nm
S7
Figure S6. FTIR spectra of GO, f-GNs, and modified f-GNs. b
Intensity (a.u.)
Intensity (a.u.)
a
GO G-N-NH2
GO G-N-OH G-N-OH-g-PCL
4000
3000
2000
G-N-NH2-g-C16
4000
1000
3000
2000
1000 -1
Wavenumber (cm )
-1
Wavenumber (cm )
c
Intensity (a.u.)
Intensity (a.u.)
d
GO G-N-Br G-N-Br-g-PS G-N-PS
GO G-N-COOH
4000
3000
2000
4000
1000 -1
Intensity (a.u.)
GO G-N-PEG350 G-N-PEG750 G-N-PEG1900
3000
2500
2000
1500 -1
2500
2000
1500
Wavenumber (cm )
e
3500
3000
-1
Wavenumber (cm )
4000
3500
1000
500
Wavenumber (cm )
S8
1000
500
Figure S7. FTIR spectra of Az-PEG350 (a), Az-PEG750 (b), Az-PEG1900 (c), Az-C16 (d), Az-PS (e), and GPC curve of Az-PS (f). a
Intensity (a.u.)
Intensity (a.u.)
b
2104 -N3 4000
3500
3000
2500
2000
2104 -N3
1500
1000
4000
500
3500
3000
2500
2000
1500
1000
-1
-1
Wavenumber (cm )
Wavenumber (cm )
c
Intensity (a.u.)
Intensity (a.u.)
d
2106 -N3
4000
3500
3000
2500
2000
1500
1000
3500
500
2106 -N3
3000
2500
2000
1500
1000
-1
Wavenumber (cm )
-1
Wavenumber (cm )
e Intensity (a.u.)
f
4000
2104 -N3
3500
3000
2500
2000
1500
1000
3
500
10
-1
Wavenumber (cm )
4
10
Molecular Weight (g/mol)
S9
500
G-N-Br
G-N-NH2
G-N-COOH
G-N-OH
GO
S10
toluene
n-hexane
chloroform
methanol
ethanol
ethylene glycol
THF
acetone
NMP
DMF
DMSO
water
Figure S8. The photographs of GO, f-GNs, modified f-GNs and reduced GO in various solvents.
G-N-PEG1900
G-N-PEG750
G-N-PEG350
G-N-PS
G-N-C16
S11
toluene
n-hexane
chloroform
methanol
ethanol
ethylene glycol
THF
acetone
NMP
DMF
DMSO
water
Figure S8 continued
Reduced GO
G-N-Br-g-PS
G-N-NH2-g-C16 G-N-OH-g-PCL
S12
toluene
n-hexane
chloroform
methanol
ethanol
ethylene glycol
THF
acetone
NMP
DMF
DMSO
water
Figure S8 continued
