Mechanism of ethanol/water reverse separation through a functional graphene membrane: a molecular simulation investigation

Abstract

Reverse-selective membranes have attracted considerable interest for bioethanol production. However, to date, the reverse-separation performance of ethanol/water is poor and the separation mechanism is unclear. Graphene-based membranes with tunable apertures and functional groups have shown substantial potential for use in molecular separation. Using molecular dynamics simulations, for the first time, we reveal two-way selectivity in ethanol/water separation through functional graphene membranes. Pristine graphene (PG) exhibits reverse-selective behavior with higher ethanol fluxes than water, resulting from the preferential adsorption for ethanol. Color flow mappings show that this ethanol-permselective process is initiated by the presence of ethanol-enriched and water-barren pores; this has not been reported in previous studies. In contrast, water molecules are preferred for hydroxylated graphene membranes because of the synergistic effects of molecular sieving and functional-group attraction. A simulation of the operando condition shows that the PG membrane with an aperture size of 3.8 Å achieves good separation performance, with an ethanol/water separation factor of 34 and a flux value of 69.3 kg∙m^‒2∙h^‒1∙bar^‒1. This study provides new insights into the reverse-selective mechanism of porous graphene membranes and a new avenue for efficient biofuel production.

Keywords

reverse separation / graphene membrane / ethanol/water separation / molecular simulation

参考文献

[1] Merkel T C, Freeman B D, Spontak R J, He Z, Pinnau I, Meakin P, Hill A J. Ultrapermeable, reverse-selective nanocomposite membranes. Science, 2002, 296(5567): 519–522

[2] Khakpay A, Scovazzo P. Reverse-selective behavior of room temperature ionic liquid based membranes for natural gas processing. Journal of Membrane Science, 2018, 545: 204–212

[3] Yu S, Qin B, Yang F, Xie M, Xue L, Zhao Z, Wang K. Unlocking the limits of diffusion and adsorption of metal-crosslinked reduced graphene oxide membranes for gas separation. Applied Surface Science, 2022, 586: 152868

[4] Lau C H, Li P, Li F, Chung T S, Paul D R. Reverse-selective polymeric membranes for gas separations. Progress in Polymer Science, 2013, 38(5): 740–766

[5] Mushardt H, Kramer V, Hülagü D, Brinkmann T, Kraume M. Development of solubility selective mixed matrix membranes for gas separation. Chemie ingenieur technik, 2014, 86(1–2): 83–91

[6] Ahmed I, Pa N F C, Nawawi M G M, Rahman W A W A. Modified polydimethylsiloxane/polystyrene blended IPN pervaporation membrane for ethanol/water separation. Journal of Applied Polymer Science, 2011, 122(4): 2666–2679

[7] Cheng X Q, Konstas K, Doherty C M, Wood C D, Mulet X, Xie Z, Ng D, Hill M R, Lau C H, Shao L. Organic microporous nanofillers with unique alcohol affinity for superior ethanol recovery toward sustainable biofuels. ChemSusChem, 2017, 10(9): 1887–1891

[8] Sanaeepur H, Ebadi Amooghin A, Bandehali S, Moghadassi A, Matsuura T, van der Bruggen B. Polyimides in membrane gas separation: monomer’s molecular design and structural engineering. Progress in Polymer Science, 2019, 91: 80–125

[9] Li Y, Chung T S, Cao C, Kulprathipanja S. The effects of polymer chain rigidification, zeolite pore size and pore blockage on polyethersulfone (PES)-zeolite a mixed matrix membranes. Journal of Membrane Science, 2005, 260(1): 45–55

[10] Mao H, Zhen H G, Ahmad A, Zhang A S, Zhao Z P. In situ fabrication of MOF nanoparticles in PDMS membrane via interfacial synthesis for enhanced ethanol permselective pervaporation. Journal of Membrane Science, 2019, 573: 344–358

[11] Pan Y, Zhu T, Xia Q, Yu X, Wang Y. Constructing superhydrophobic ZIF-8 layer with bud-like surface morphology on PDMS composite membrane for highly efficient ethanol/water separation. Journal of Environmental Chemical Engineering, 2021, 9(1): 104977

[12] Pan Y, Yu X. Preparation of zeolitic imidazolate framework-91 and its modeling for pervaporation separation of water/ethanol mixtures. Separation and Purification Technology, 2020, 237: 116330

[13] He X, Wang T, Huang J, Chen J, Li J. Fabrication and characterization of superhydrophobic PDMS composite membranes for efficient ethanol recovery via pervaporation. Separation and Purification Technology, 2020, 241: 116675

[14] Zhu T, Xu S, Yu F, Yu X, Wang Y. ZIF-8@GO composites incorporated polydimethylsiloxane membrane with prominent separation performance for ethanol recovery. Journal of Membrane Science, 2020, 598: 117681

[15] Zhu T, Yu X, Yi M, Wang Y. Facile covalent crosslinking of zeolitic imidazolate framework/polydimethylsiloxane mixed matrix membrane for enhanced ethanol/water separation performance. ACS Sustainable Chemistry & Engineering, 2020, 8(33): 12664–12676

[16] Kang J, Choi Y, Kim J P, Kim J H, Kim J Y, Kwon O, Kim D I, Kim D W. Thermally-induced pore size tuning of multilayer nanoporous graphene for organic solvent nanofiltration. Journal of Membrane Science, 2021, 637: 119620

[17] Liu Y, Bai Z, Lin G, Wang L, Xu X, He L, Liu X. Covalent cross-linking mediated TA-APTES NPs to construct a high-efficiency GO composite membrane for dye/salt separation. Applied Surface Science, 2022, 584: 152595

[18] Liu G, Jin W, Xu N. Graphene-based membranes. Chemical Society Reviews, 2015, 44(15): 5016–5030

[19] Moreno C, Vilas-Varela M, Kretz B, Garcia-Lekue A, Costache M V, Paradinas M, Panighel M, Ceballos G, Valenzuela S O, Peña D, Mugarza A. Bottom-up synthesis of multifunctional nanoporous graphene. Science, 2018, 360(6385): 199–203

[20] Jang J, Nam Y T, Kim D, Kim Y J, Kim D W, Jung H T. Turbostratic nanoporous carbon sheet membrane for ultrafast and selective nanofiltration in viscous green solvents. Journal of Materials Chemistry A: Materials for Energy and Sustainability, 2020, 8(17): 8292–8299

[21] Gravelle S, Yoshida H, Joly L, Ybert C, Bocquet L. Carbon membranes for efficient water−ethanol separation. Journal of Chemical Physics, 2016, 145(12): 124708

[22] Kommu A, Singh J K. Separation of ethanol and water using graphene and hexagonal boron nitride slit pores: a molecular dynamics study. Journal of Physical Chemistry C, 2017, 121(14): 7867–7880

[23] Liu Q, Chen M, Mao Y, Liu G. Theoretical study on Janus graphene oxide membrane for water transport. Frontiers of Chemical Science and Engineering, 2021, 15(4): 913–921

[24] Liu Q, Gupta K M, Xu Q, Liu G, Jin W. Gas permeation through double-layer graphene oxide membranes: the role of interlayer distance and pore offset. Separation and Purification Technology, 2019, 209: 419–425

[25] Liu Q, Wu Y, Wang X, Liu G, Zhu Y, Tu Y, Lu X, Jin W. Molecular dynamics simulation of water−ethanol separation through monolayer graphene oxide membranes: significant role of O/C ratio and pore size. Separation and Purification Technology, 2019, 224: 219–226

[26] Cohen-Tanugi D, Grossman J C. Water desalination across nanoporous graphene. Nano Letters, 2012, 12(7): 3602–3608

[27] Li H, Lv W, Xu J, Hu J, Liu H. Can flexible framework fillers keep breathing in mixed matrix membranes to enhance separation performance?. Journal of Membrane Science, 2020, 614: 118426

[28] Gupta K M, Liu J, Jiang J. A molecular simulation protocol for membrane pervaporation. Journal of Membrane Science, 2019, 572: 676–682

[29] Liu Q, Zhu H, Liu G, Jin W. Efficient separation of (C₁–C₂) alcohol solutions by graphyne membranes: a molecular simulation study. Journal of Membrane Science, 2022, 644: 120139

[30] Jorgensen W L, Chandrasekhar J, Madura J D, Impey R W, Klein M L. Comparison of simple potential functions for simulating liquid water. Journal of Chemical Physics, 1983, 79(2): 926–935

[31] Jorgensen W L, Maxwell D S, Tirado-Rives J. Development and testing of the OPLS all-atom force field on conformational energetics and properties of organic liquids. Journal of the American Chemical Society, 1996, 118(45): 11225–11236

[32] Wennberg C L, Murtola T, Páll S, Abraham M J, Hess B, Lindahl E. Direct-space corrections enable fast and accurate Lorentz–Berthelot combination rule Lennard–Jones lattice summation. Journal of Chemical Theory and Computation, 2015, 11(12): 5737–5746

[33] van der Spoel D, Lindahl E, Hess B, Groenhof G, Mark A E, Berendsen H J. GROMACS: fast, flexible, and free. Journal of Computational Chemistry, 2005, 26(16): 1701–1718

[34] Humphrey W, Dalke A, Schulten K. VMD: visual molecular dynamics. Journal of Molecular Graphics, 1996, 14(1): 33–38

[35] Wei W, Liu J, Jiang J. Atomistic simulation study of polyarylate/zeolitic-imidazolate framework mixed-matrix membranes for water desalination. ACS Applied Nano Materials, 2020, 3(10): 10022–10031

[36] Cohen-Tanugi D, Grossman J C. Water permeability of nanoporous graphene at realistic pressures for reverse osmosis desalination. Journal of Chemical Physics, 2014, 141(7): 074704

[37] Liu J, Wei W, Jiang J. A highly rigid and conjugated microporous polymer membrane for solvent permeation and biofuel purification: a molecular simulation study. ACS Sustainable Chemistry & Engineering, 2020, 8(7): 2892–2900

[38] Guo Y, Xie W, Li H, Li J, Hu J, Liu H. Construction of hydrophobic channels on Cu(I)-MOF surface to improve selective adsorption desulfurization performance in presence of water. Separation and Purification Technology, 2022, 285: 120287

[39] An S, Lu C, Xu Q, Lian C, Peng C, Hu J, Zhuang X, Liu H. Constructing catalytic crown ether-based covalent organic frameworks for electroreduction of CO₂. ACS Energy Letters, 2021, 6(10): 3496–3502

[40] Cohen-Tanugi D, Lin L C, Grossman J C. Multilayer nanoporous graphene membranes for water desalination. Nano Letters, 2016, 16(2): 1027–1033

[41] Zhang L, Wu G, Jiang J. Adsorption and diffusion of CO₂ and CH₄ in zeolitic imidazolate framework-8: effect of structural flexibility. Journal of Physical Chemistry C, 2014, 118(17): 8788–8794

[42] Nakagawa K, Araya S, Ushio K, Kunimatsu M, Yoshioka T, Shintani T, Kamio E, Tung K L, Matsuyama H. Controlling interlayer spacing and organic solvent permeation in laminar graphene oxide membranes modified with crosslinker. Separation and Purification Technology, 2021, 276: 119279

[43] Wang J, Zhang P, Liang B, Liu Y, Xu T, Wang L, Cao B, Pan K. Graphene oxide as an effective barrier on a porous nanofibrous membrane for water treatment. ACS Applied Materials & Interfaces, 2016, 8(9): 6211–6218

Acknowledgments

This work was financially supported by the University Natural Science Research Project of Anhui Province (Grant No. KJ2020A0286), the Anhui Provincial Natural Science Foundation (Grant No. 2108085QB50), and the Natural Science Foundation of Jiangsu Province (Grant No. BK20220002). The numerical calculations in this paper have been done on the supercomputing system in the Supercomputing Center of University of Science and Technology of China.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://dx.doi.org/10.1007/s11705-022-2246-z and is accessible for authorized users.

版权

2022 Higher Education Press