Supporting Information Wiley-VCH 2014 69451 Weinheim, Germany
Bioinspired Green Composite Lotus Fibers** Mengxi Wu, Hua Shuai, Qunfeng Cheng,* and Lei Jiang anie_201310656_sm_miscellaneous_information.pdf
Supporting Information
60
Fraction (%)
50 40 30 20 10 0
2.0
3.0
5.0 4.0 6.0 Diameter (μm)
7.0
Figure S1. The diameter of lotus fibers distribute in the range of 3.0-6.0 μm, and the average of lotus fibers can be calculated about 5.0 μm.
Figure S2. The digital photograph of the continuously collected bioinspired green composite fiber (GCF) on the stick.
Figure S3. The SEM images show the twisted single (a), double (b), triple (c), and quadruple (d) lotus fiber bundles. e) the twisted whole lotus fiber bundles from one stem.
a)
b)
500
400
Stress( MPa)
400
Stress( MPa)
500
300
200
300
200
100
100
0
0 0
2
4
6
8
0
10
2
c)
d)
500
Stress( MPa)
Stress( MPa)
6
8
10
8
10
500
400
400
300
200
300
200
100
100
0
0 0
2
4
6
8
10
Strain(%)
e)
4
Strain(%)
Strain(%)
0
2
4
6
Strain(%)
500
Stress( MPa)
400
300
200
100
0 0
2
4
6
8
10
Strain(%)
Figure S4. The corresponding tensile stress-strain curves of twisted LF bundles: a) single, b) double, c) triple, d) quadruple and e) the whole LF bundles from one stem.
Figure S5. SEM images of pure lotus fiber with different twist angles: a) 10 ± 2o, b) 15 ± 1.5 o, c) 20 ± 3o, and the diameter is about 60 μm.
100
PVA LF GCF-I GCF-II GCF-III
Weight loss (%)
80
60
40
20
0 0
200
400 Temperature (oC)
600
800
Figure S6. TGA curves of pure PVA, lotus fiber (LF) and three kinds of lotus composite fibers (GCF-I, GCF-II and GCF-III). The PVA almost decomposes at around 800 ºC (black curve) and the LF remains about 6.7 %. The other three composite fiber remains about 6 %, 5.2 %, and 4.2 %, corresponding to GCF-I (blue curve), GCF-II (green curve), and GCF-III (magenta curve), respectively. Thus, the PVA loading in the composite fiber is calculated to be about 10.4 wt%, 22.4 wt%, and 37.3 wt%, respectively.
Figure S7. SEM images of GCF: a) and b) is the surface morphology of GCF-I, shows the PVA is not enough for condensing the lotus fiber. c) and d) GCF-II shows the better interface between PVA and lotus fiber. e) and f) GCF-III shows much more PVA on the surface of lotus fiber.
800
LF GCF-I GCF-II GCF-III
Stress(MPa)
600
400
200
0 0
1
2
3 4 Strain (%)
5
6
7
Figure S8. Tensile stress-strain curves of lotus fiber (black curve) and composite fibers of GCF-I (red curve), GCF-II (blue curve), and GCFIII (green curve): the tensile strength and Young’s modulus of lotus fiber are about 329.4 ± 28.6 MPa and 6.3 ± 1.2 GPa, respectively. After introducing the PVA, the mechanical properties of composite fiber dramatically increase. The tensile strength increases to 439.5 ± 109.9 MPa, 622.5± 60.3, and 559.3 ± 54.8 corresponding to GCF-I, GCF-II, and GCF-III, respectively. And the Young’s modulus reaches 10.8 ± 5.6 GPa, 22.4 ± 2.9 GPa, and 19.1 ± 3.7 for GCF-I, GCF-II, and GCF-III, respectively.
Figure S9. Tensile stress-strain curves of pure PVA film and PVA with different treatments including . glutaraldehyde (GA) and heated. The pure PVA film shows tensile strength of 76.1 ± 4.2 MPa, Young’s modulus of 2.4 ± 0.3 GPa, and strain of 456.5 ± 87.9% (black curve). After cross-linking with GA, the tensile strength increases to 93.6 ± 14.9 MPa (red curve), and 118.2 ± 35.3 MPa (blue curve) for different ratio with GA of 0.1 and 1, respectively. Compared to GA cross-linking, the heat treatment (60 oC/2h) enhances the tensile strength to 148.8 ± 7.3 MPa, however, the strain dramatically decreases to 42.5 ± 15.8 % (magenta curve). Combining the heat treatment and GA (ratios of 0.1 and 1), the tensile strength of treated PVA can reach 142.9 ± 4.2 MPa (green curve) and 202.7 ± 41.2 MPa (orange curve), which is 1.88 and 2.66 times than that of pure PVA, respectively.
Heated and GA treated GCF GA treated GCF
GCF LF PVA
4000
3500
3000
2500
2000
-1
1500
1000
Wavenumbers (cm ) Figure S10. FTIR spectrum of pure PVA, LF, GCF, GA treated GCF and combination of heated and GA treated of GCF. The characteristic peaks of secondary alcohol around 1100 cm-1 disappear, indicating the successful cross-linking by GA.
Table S1. The mechanical properties of the twisted LF bundles. Specimen Twisted single LF bundle
No.
Tensile strength (MPa)
Young’s modulus (GPa)
Strain (%)
Toughness 3 (MJ/m )
439.2
9.4
8.4
21.7
436.4
12.7
4.5
11.2
407.5
10.5
4.0
8.2
Average ± SD
427.7 ± 17.5
10.9 ± 1.7
5.6 ± 2.4
13.7 ± 7.1
1
415.5
20.9
4.05
9.73
2
405.3
11.0
4.86
10.92
3
323.8
13.9
4.15
7.84
Average ± SD
381.5 ± 50.3
15.3 ± 5.1
4.4 ± 0.4
9.5 ± 1.6
1
191.34
8.0
4.72
5.36
2
244.82
10.6
4.96
7.45
3
197.21
14.7
6.51
8.95
Average ± SD
211.1 ± 29.3
11.1 ± 3.4
5.4 ± 1.0
7.3 ± 1.8
1
198.0
8.1
4.2
5.0
2
156.6
5.3
7.5
6.3
3
169.1
6.9
4.5
4.9
Average ± SD
174.6 ± 21.2
6.8 ± 1.4
5.4 ± 1.8
5.4 ± 0.8
1
308.1
5.2
4.5
7.4
2
318.2
6.1
4.2
7.3
3
361.9
7.6
4.6
8.1
Average ± SD
329.4 ± 28.6
6.3 ± 1.2
4.4 ± 0.2
7.6 ± 0.4
1 2 3
Twisted double LF bundle
Twisted triple LF bundle
Twisted quadruple LF bundle
Twisted LF bundles from one stem
Table S2. Mechanical properties of natural fibers and bioinspired green composite fibers.
Elongation (%)
Specific tensile strength (σ/ρ, kN·m/kg)
Specific modulus (E/ρ, MN·m/kg)
27.6
1.2-3.2
230-690
18.4
[1]
287-800
5.5-12.6
3.0-10.0
179-500
3-8
[7a, 8, 25]
1.3-1.5
393-800
10-55
1.5-1.8
262-533
7-37
[7a, 8, 25]
Hemp fiber
1.5
550-900
70
1.6
367-600
47
[7a]
Sisal fiber
1.3-1.5
511-635
9.4-28
2.0-2.5
340-423
6.3-18.7
[7a, 8, 25]
Ramie fiber
1.5
400-938
44
2.0-3.8
267-625
29.3
[7a, 25]
Coir fiber
1.2
131-220
4-6
15-30
109-183
3.3-5
[7a, 8, 25]
Cocoon silk
1.3-1.4
620.5
7
14.5
443.2
10.4
[13]
Lotus fiber
1.18
230-340
6
5-7
195-288
4.2-5.9
Bioinspired green composite fiber
1.19
675-749
45
2.1
629
37.8
Specimen
Density 3 (g/cm )
Tensile strength (MPa)
Young’s modulus (GPa)
Flax fiber
1.5
345-1035
Cotton fiber
1.5-1.6
Jute fiber
References
Our work
Bioinspired Green Composite Lotus Fibers** Mengxi Wu, Hua Shuai, Qunfeng Cheng,* and Lei Jiang anie_201310656_sm_miscellaneous_information.pdf
Supporting Information
60
Fraction (%)
50 40 30 20 10 0
2.0
3.0
5.0 4.0 6.0 Diameter (μm)
7.0
Figure S1. The diameter of lotus fibers distribute in the range of 3.0-6.0 μm, and the average of lotus fibers can be calculated about 5.0 μm.
Figure S2. The digital photograph of the continuously collected bioinspired green composite fiber (GCF) on the stick.
Figure S3. The SEM images show the twisted single (a), double (b), triple (c), and quadruple (d) lotus fiber bundles. e) the twisted whole lotus fiber bundles from one stem.
a)
b)
500
400
Stress( MPa)
400
Stress( MPa)
500
300
200
300
200
100
100
0
0 0
2
4
6
8
0
10
2
c)
d)
500
Stress( MPa)
Stress( MPa)
6
8
10
8
10
500
400
400
300
200
300
200
100
100
0
0 0
2
4
6
8
10
Strain(%)
e)
4
Strain(%)
Strain(%)
0
2
4
6
Strain(%)
500
Stress( MPa)
400
300
200
100
0 0
2
4
6
8
10
Strain(%)
Figure S4. The corresponding tensile stress-strain curves of twisted LF bundles: a) single, b) double, c) triple, d) quadruple and e) the whole LF bundles from one stem.
Figure S5. SEM images of pure lotus fiber with different twist angles: a) 10 ± 2o, b) 15 ± 1.5 o, c) 20 ± 3o, and the diameter is about 60 μm.
100
PVA LF GCF-I GCF-II GCF-III
Weight loss (%)
80
60
40
20
0 0
200
400 Temperature (oC)
600
800
Figure S6. TGA curves of pure PVA, lotus fiber (LF) and three kinds of lotus composite fibers (GCF-I, GCF-II and GCF-III). The PVA almost decomposes at around 800 ºC (black curve) and the LF remains about 6.7 %. The other three composite fiber remains about 6 %, 5.2 %, and 4.2 %, corresponding to GCF-I (blue curve), GCF-II (green curve), and GCF-III (magenta curve), respectively. Thus, the PVA loading in the composite fiber is calculated to be about 10.4 wt%, 22.4 wt%, and 37.3 wt%, respectively.
Figure S7. SEM images of GCF: a) and b) is the surface morphology of GCF-I, shows the PVA is not enough for condensing the lotus fiber. c) and d) GCF-II shows the better interface between PVA and lotus fiber. e) and f) GCF-III shows much more PVA on the surface of lotus fiber.
800
LF GCF-I GCF-II GCF-III
Stress(MPa)
600
400
200
0 0
1
2
3 4 Strain (%)
5
6
7
Figure S8. Tensile stress-strain curves of lotus fiber (black curve) and composite fibers of GCF-I (red curve), GCF-II (blue curve), and GCFIII (green curve): the tensile strength and Young’s modulus of lotus fiber are about 329.4 ± 28.6 MPa and 6.3 ± 1.2 GPa, respectively. After introducing the PVA, the mechanical properties of composite fiber dramatically increase. The tensile strength increases to 439.5 ± 109.9 MPa, 622.5± 60.3, and 559.3 ± 54.8 corresponding to GCF-I, GCF-II, and GCF-III, respectively. And the Young’s modulus reaches 10.8 ± 5.6 GPa, 22.4 ± 2.9 GPa, and 19.1 ± 3.7 for GCF-I, GCF-II, and GCF-III, respectively.
Figure S9. Tensile stress-strain curves of pure PVA film and PVA with different treatments including . glutaraldehyde (GA) and heated. The pure PVA film shows tensile strength of 76.1 ± 4.2 MPa, Young’s modulus of 2.4 ± 0.3 GPa, and strain of 456.5 ± 87.9% (black curve). After cross-linking with GA, the tensile strength increases to 93.6 ± 14.9 MPa (red curve), and 118.2 ± 35.3 MPa (blue curve) for different ratio with GA of 0.1 and 1, respectively. Compared to GA cross-linking, the heat treatment (60 oC/2h) enhances the tensile strength to 148.8 ± 7.3 MPa, however, the strain dramatically decreases to 42.5 ± 15.8 % (magenta curve). Combining the heat treatment and GA (ratios of 0.1 and 1), the tensile strength of treated PVA can reach 142.9 ± 4.2 MPa (green curve) and 202.7 ± 41.2 MPa (orange curve), which is 1.88 and 2.66 times than that of pure PVA, respectively.
Heated and GA treated GCF GA treated GCF
GCF LF PVA
4000
3500
3000
2500
2000
-1
1500
1000
Wavenumbers (cm ) Figure S10. FTIR spectrum of pure PVA, LF, GCF, GA treated GCF and combination of heated and GA treated of GCF. The characteristic peaks of secondary alcohol around 1100 cm-1 disappear, indicating the successful cross-linking by GA.
Table S1. The mechanical properties of the twisted LF bundles. Specimen Twisted single LF bundle
No.
Tensile strength (MPa)
Young’s modulus (GPa)
Strain (%)
Toughness 3 (MJ/m )
439.2
9.4
8.4
21.7
436.4
12.7
4.5
11.2
407.5
10.5
4.0
8.2
Average ± SD
427.7 ± 17.5
10.9 ± 1.7
5.6 ± 2.4
13.7 ± 7.1
1
415.5
20.9
4.05
9.73
2
405.3
11.0
4.86
10.92
3
323.8
13.9
4.15
7.84
Average ± SD
381.5 ± 50.3
15.3 ± 5.1
4.4 ± 0.4
9.5 ± 1.6
1
191.34
8.0
4.72
5.36
2
244.82
10.6
4.96
7.45
3
197.21
14.7
6.51
8.95
Average ± SD
211.1 ± 29.3
11.1 ± 3.4
5.4 ± 1.0
7.3 ± 1.8
1
198.0
8.1
4.2
5.0
2
156.6
5.3
7.5
6.3
3
169.1
6.9
4.5
4.9
Average ± SD
174.6 ± 21.2
6.8 ± 1.4
5.4 ± 1.8
5.4 ± 0.8
1
308.1
5.2
4.5
7.4
2
318.2
6.1
4.2
7.3
3
361.9
7.6
4.6
8.1
Average ± SD
329.4 ± 28.6
6.3 ± 1.2
4.4 ± 0.2
7.6 ± 0.4
1 2 3
Twisted double LF bundle
Twisted triple LF bundle
Twisted quadruple LF bundle
Twisted LF bundles from one stem
Table S2. Mechanical properties of natural fibers and bioinspired green composite fibers.
Elongation (%)
Specific tensile strength (σ/ρ, kN·m/kg)
Specific modulus (E/ρ, MN·m/kg)
27.6
1.2-3.2
230-690
18.4
[1]
287-800
5.5-12.6
3.0-10.0
179-500
3-8
[7a, 8, 25]
1.3-1.5
393-800
10-55
1.5-1.8
262-533
7-37
[7a, 8, 25]
Hemp fiber
1.5
550-900
70
1.6
367-600
47
[7a]
Sisal fiber
1.3-1.5
511-635
9.4-28
2.0-2.5
340-423
6.3-18.7
[7a, 8, 25]
Ramie fiber
1.5
400-938
44
2.0-3.8
267-625
29.3
[7a, 25]
Coir fiber
1.2
131-220
4-6
15-30
109-183
3.3-5
[7a, 8, 25]
Cocoon silk
1.3-1.4
620.5
7
14.5
443.2
10.4
[13]
Lotus fiber
1.18
230-340
6
5-7
195-288
4.2-5.9
Bioinspired green composite fiber
1.19
675-749
45
2.1
629
37.8
Specimen
Density 3 (g/cm )
Tensile strength (MPa)
Young’s modulus (GPa)
Flax fiber
1.5
345-1035
Cotton fiber
1.5-1.6
Jute fiber
References
Our work
