Facile Preparation of Graphene Oxide Membranes for Gas Separation
Supplementary Information
Facile Preparation of Graphene Oxide Membranes for Gas Separation
Chenglong Chi, Xuerui Wang, Yongwu Peng, Yuhong Qian, Zhigang Hu, Jinqiao Dong, and Dan Zhao*
Department of Chemical & Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore
Correspondence and requests for materials should be addressed to D.Z. [email protected]).
(E-mail:
S1
Figure S1. (A) AFM image of exfoliated GO nanosheets before purification; (B) AFM image of exfoliated GO nanosheets after 5 time purification. Before purification, we can see some smaller GO nanoparticles mixed with larger GO nanosheets. After purification, most of the small GO nanoparticles are removed, leading to increased average size of GO nanosheets seen in Figure 3 and Figure S3.
S2
Figure S2. TEM images of exfoliated and purified GO nanosheets. These TEM images indicate that GO can be successfully exfoliated by the mild freeze-thaw method into few-layered nanosheets with easily curled morphology.
S3
50
Before purification After purification
Number (%)
40 30 20 10 0 0
1
2
3
4
5
6
7
8
9
10
Size (µ µm) Figure S3. Raw particle size distribution data of GO nanosheets before and after purification. The average lateral size of GO nanosheets can be increased from 9 µm to 13 µm after purification because of the removal of small GO nanoparticles.
S4
Figure S4. Cross-sectional SEM images of GO membranes prepared by spin coating. It can be observed from these images that the GO membranes are formed by the stacking of GO nanosheets to a thickness of around 20 nm.
S5
H2 adsorption
30
Vads (STP) (cm3/g)
CO2 adsorption N2 adsorption
25
CH4 adsorption
20 15 10 5 0 0
20
40
60
80
100
Absolute Pressure (kPa) Figure S5. Adsorption isotherms of different gases in GO membrane at 298 K. This indicates the relatively similar gas sorption amount of various gases into GO membranes under conditions similar to membrane tests (298 K, 1 atm).
S6
Figure S6. Apparatus scheme of gas separation measurement.
S7
Facile Preparation of Graphene Oxide Membranes for Gas Separation
Chenglong Chi, Xuerui Wang, Yongwu Peng, Yuhong Qian, Zhigang Hu, Jinqiao Dong, and Dan Zhao*
Department of Chemical & Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore
Correspondence and requests for materials should be addressed to D.Z. [email protected]).
(E-mail:
S1
Figure S1. (A) AFM image of exfoliated GO nanosheets before purification; (B) AFM image of exfoliated GO nanosheets after 5 time purification. Before purification, we can see some smaller GO nanoparticles mixed with larger GO nanosheets. After purification, most of the small GO nanoparticles are removed, leading to increased average size of GO nanosheets seen in Figure 3 and Figure S3.
S2
Figure S2. TEM images of exfoliated and purified GO nanosheets. These TEM images indicate that GO can be successfully exfoliated by the mild freeze-thaw method into few-layered nanosheets with easily curled morphology.
S3
50
Before purification After purification
Number (%)
40 30 20 10 0 0
1
2
3
4
5
6
7
8
9
10
Size (µ µm) Figure S3. Raw particle size distribution data of GO nanosheets before and after purification. The average lateral size of GO nanosheets can be increased from 9 µm to 13 µm after purification because of the removal of small GO nanoparticles.
S4
Figure S4. Cross-sectional SEM images of GO membranes prepared by spin coating. It can be observed from these images that the GO membranes are formed by the stacking of GO nanosheets to a thickness of around 20 nm.
S5
H2 adsorption
30
Vads (STP) (cm3/g)
CO2 adsorption N2 adsorption
25
CH4 adsorption
20 15 10 5 0 0
20
40
60
80
100
Absolute Pressure (kPa) Figure S5. Adsorption isotherms of different gases in GO membrane at 298 K. This indicates the relatively similar gas sorption amount of various gases into GO membranes under conditions similar to membrane tests (298 K, 1 atm).
S6
Figure S6. Apparatus scheme of gas separation measurement.
S7
