Supporting Information · Fig. S8 (a) is the CO2/H2 selectivity of GO-SILM on PC substrate under different EEF; (b) is the CO2/H2 selectivity of GO-SILM with [EMIM][BF4] under different
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Supporting Information
Selectively Tune Gas Permeation through Ionic Liquid Filled Nanoslits by Electric Field
Wen Ying,† Ke Zhou,† Quangang Hou,† Danke Chen, Yi Guo, Jun Zhang, Youguo Yan,* Zhiping Xu* and Xinsheng Peng*
ensemble averaging performed over a set of 5 independent MD runs. The representative
PMF curves (G) is illustrated in Fig. S9 and the forward/backward process represents
gas absorption/desorption from the IL.9,10 Here, the difference between the minimum
in PMF related to the vacuum value is defined as the absorption free energy Gabs, which
is 2.37 kcal/mol for CO2 in the absence of EEF, in consistency with the results reported
for CO2 absorbed to the surface of bulk [BMIM][BF4].9 The absorption free energy
Gabs(E) is shown in Fig. S10 as a function of EEF, which is normalized by its value of
in the absence of EEF. As for the desorption process on the permeate side, which is the
reverse process of absorption, the desorption free energy is . We can 𝐺𝑑𝑒𝑠(𝐸) = 𝐺𝑎𝑏𝑠( ‒ 𝐸)
then estimate the permeability as a function of E, , where 𝑝(𝐸) = ~𝑒𝑥𝑝(∆𝐺(𝐸)/𝑘𝐵𝑇)
. The values of ∆G(E) is summarized in ∆𝐺(𝐸) = 𝐺𝑎𝑏𝑠(𝐸) ‒ 𝐺𝑑𝑒𝑠(𝐸) = 𝐺𝑎𝑏𝑠(𝐸) ‒ 𝐺𝑎𝑏𝑠( ‒ 𝐸)
Fig. 3a for all the gas. The results are normalized by the value of in the absence of EEF,
which can be used to quantize the enhancement of P comparing to without EEF.
Free Volume and Anion-cation Interaction Energy Calculations: 190 pairs of ionic
liquid are filled in a 2D membrane packaged by two parallel GO walls with the size of
10.0×5.0×2.2 nm3, as shown in Fig. S11. PBCs were used in all three directions. The
length of box in electric field direction is 10 nm to eliminate the interaction of periodic
images. The constant external electric field are applied in z direction from -2 V/Å to 2
V/Å. For each system, the simulation was conducted in a canonical ensemble (NVT) at
298 K controlled by the Nosé-Hoover thermostat. The free volume is calculated by the
Connolly Surface.12 All the data were calculated after an equilibrium molecular
dynamics of 2 ns. The interlayer spacing of GO sheets is set as 2.2 nm, which is
consistent with the XRD experiments. In the simulations, all atoms in the GO sheets
were fixed except the hydroxyl and epoxy groups.
Figures and tables
Fig. S1 AFM images of GO nanosheets.
Fig. S2 XRD patterns of a typical GO membrane and GO-SILM.
Fig. S3 The SEM imagines of GO-SILMs with different thickness. (a)-(d), the cross-section of GO-SILMs with the thickness of 72 nm, 170 nm, 280 nm, 380 nm, including 0.01, 0.025, 0.04, 0.05 mg GO, respectively.
Fig. S4 The FTIR spectrum of GO, [BMIM][BF4] and GO-SILM.
Fig. S5 The DSC curves of GO, [BMIM][BF4] and GO-SILM.
Fig. S6 The gas permeance and separation of GO-SILMs with different thickness.
Fig. S7 The separation performance (selectivity vs. permeance) of GO-SILMs under EEF compared with other membranes. (a) CO2/H2, (b) CO2/CH4 and (c) CO2/N2. The detail data is shown in Table S3 and from the Supplementary references.
Fig. S8 (a) is the CO2/H2 selectivity of GO-SILM on PC substrate under different EEF; (b) is the CO2/H2 selectivity of GO-SILM with [EMIM][BF4] under different EEF.
Fig. S9 Illustration of molecular simulation for IL film models. The two grey rectangles are GO walls with the position of upper one at z = 0.5 nm. The interaction between gas and GO walls is turned off so gas molecules can permeate into the IL. The gas molecules are pulled by a harmonic spring with its end point moving from z = 0 to z = 1.2 nm in the SMD simulations. The representative PMF curves denote the absorption/desorption processes of gases into/from ILs. The difference between the free energy minimum in PMF and the value in vacuum is defined as the surficial absorption free energy .∆𝐺
Fig. S10 The adsorption free energy (Gabs) calculated for gases in confined IL films under a finite EEF. The results are normalized by the value of in the absence of EEF.
Fig. S11 MD models to study the free volume and anion-cation interaction energy. White, grey, red, blue, purple and green balls denote the hydrogen, carbon, oxygen, nitrogen, fluorine and boron atom respectively.
Table S1 The list of GO weight content in GO-SILMs with different thickness.
Membrane Thickness (nm) Original GO (nm) Weight of GO (mg)
References1 H. Huang, Y. Mao, Y. Ying, Y. Liu, L. Sun and X. Peng, Chem Commun (Camb), 2013, 49, 5963-
5965.2 W. Ying, J. Cai, K. Zhou, D. Chen, Y. Ying, Y. Guo, X. Kong, Z. Xu and X. Peng, ACS Nano, 2018,
12, 5385-5393.3 S. Plimpton, J. Comput. Phys., 1995, 117, 1-19.4 W. L. Jorgensen, D. S. Maxwell and J. Tirado-Rives, J. Am. Chem. Soc., 1996, 118, 11225-11236.5 W. D. Cornell, P. Cieplak, C. I. Bayly, I. R. Gould, K. M. Merz, D. M. Ferguson, D. C. Spellmeyer,
T. Fox, J. W. Caldwell and P. A. Kollman, J. Am. Chem. Soc., 1995, 117, 5179-5197.6 J. de Andrade, E. S. Böes and H. Stassen, J. Phys. Chem. B, 2002, 106, 13344-13351.7 M. P. Allen and D. J. Tildesley, Computer simulation of liquids, Oxford university press, 2017.8 S. Jiao and Z. Xu, ACS Appl. Mater. Interfaces, 2015, 7, 9052-9059.9 C. D. Wick, T.-M. Chang and L. X. Dang, J. Phys. Chem. B, 2010, 114, 14965-14971.10 A. Mondal and S. Balasubramanian, J. Phys. Chem. B, 2016, 120, 4457-4466.11 S. Park, F. Khalili-Araghi, E. Tajkhorshid and K. Schulten, J. Chem. Phys., 2003, 119, 3559-3566.12 M. L. Connolly, J. Mol. Graph., 1993, 11, 139-143.13 T. H. Bae, J. S. Lee, W. Qiu, W. J. Koros, C. W. Jones and S. Nair, Angew. Chem. Int. Ed., 2010,
49, 9863-9866.14 A. K. Zulhairun and A. F. Ismail, J. Membr. Sci., 2014, 468, 20-30.15 S. Himeno, T. Tomita, K. Suzuki, K. Nakayama, K. Yajima and S. Yoshida, Ind. Eng. Chem. Res.,
2007, 46, 6989-6997.16 C. Kong, H. Du, L. Chen and B. Chen, Energy Environ. Sci., 2017, 10, 1812-1819.17 Z. Qiao, S. Zhao, M. Sheng, J. Wang, S. Wang, Z. Wang, C. Zhong and M. D. Guiver, Nat. Mater.,
2019, 18, 163-168.18 S. Duan, T. Kouketsu, S. Kazama and K. Yamada, J. Membr. Sci., 2006, 283, 2-6.19 S. Li, Z. Wang, X. Yu, J. Wang and S. Wang, Adv. Mater., 2012, 24, 3196-3200.20 Z. Qiao, Z. Wang, C. Zhang, S. Yuan, Y. Zhu, J. Wang and S. Wang, AlChE J., 2013, 59, 215-228.21 M. Wang, Z. Wang, S. Li, C. Zhang, J. Wang and S. Wang, Energy Environ. Sci., 2013, 6, 539-551.22 X. Jiang, S. Li and L. Shao, Energy Environ. Sci., 2017, 10, 1339-1344.23 Q. Song, S. K. Nataraj, M. V. Roussenova, J. C. Tan, D. J. Hughes, W. Li, P. Bourgoin, M. A. Alam,
A. K. Cheetham, S. A. Al-Muhtaseb and E. Sivaniah, Energy Environ. Sci., 2012, 5, 8359-8369.24 T. Rodenas, I. Luz, G. Prieto, B. Seoane, H. Miro, A. Corma, F. Kapteijn, F. X. Llabres i Xamena
and J. Gascon, Nat. Mater., 2015, 14, 48-55.25 J. E. Bachman and J. R. Long, Energy Environ. Sci., 2016, 9, 2031-2036.26 O. G. Nik, X. Y. Chen and S. Kaliaguine, J. Membr. Sci., 2012, 413, 48-61.27 W. Fam, J. Mansouri, H. Li, J. Hou and V. Chen, ACS Appl. Mater. Interfaces, 2018, 10, 7389-7400.28 J. Shen, G. Liu, K. Huang, W. Jin, K. R. Lee and N. Xu, Angew. Chem. Int. Ed., 2015, 54, 578-582.29 W. Fam, J. Mansouri, H. Li and V. Chen, J. Membr. Sci., 2017, 537, 54-68.30 M. Karunakaran, L. F. Villalobos, M. Kumar, R. Shevate, F. H. Akhtar and K. V. Peinemann, J.
Mater. Chem. A, 2017, 5, 649-656.31 M. Karunakaran, R. Shevate, M. Kumar and K. V. Peinemann, Chem. Commun., 2015, 51, 14187-
14190.32 H. W. Kim, H. W. Yoon, S. M. Yoon, B. M. Yoo, B. K. Ahn, Y. H. Cho, H. J. Shin, H. Yang, U.
Paik and S. Kwon, Science, 2013, 342, 91-95.
33 W. Zhao, G. He, L. Zhang, J. Ju, H. Dou, F. Nie, C. Li and H. Liu, J. Membr. Sci., 2010, 350, 279-285.34 D. Ji, Y. S. Kang and S. W. Kang, Sci. Rep., 2015, 5, 16362.35 Y. S. Park, C. Ha and S. W. Kang, RSC Adv., 2017, 7, 33568-33571.36 E. Ghasemi Estahbanati, M. Omidkhah and A. Ebadi Amooghin, ACS Appl. Mater. Interfaces, 2017,
9, 10094-10105.37 Y. Choi, G. H. Hong and S. W. Kang, J. Nanosci. Nanotechno., 2016, 16, 2832-2835.38 G. H. Hong, D. Ji and S. W. Kang, RSC Adv., 2014, 4, 16917.39 S. Safaei and R. Tavakoli, Desalination, 2017, 422, 83-90.