Nanostructured Virus Filtration Membranes Based on Two-Component

Dec 18, 2018 - Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku , Tokyo 113-8656 , Japan...
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Letter Cite This: ACS Macro Lett. 2019, 8, 24−30

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Nanostructured Virus Filtration Membranes Based on TwoComponent Columnar Liquid Crystals Kazuma Hamaguchi,† Daniel Kuo,† Miaomiao Liu,‡ Takeshi Sakamoto,† Masafumi Yoshio,§,† Hiroyuki Katayama,*,‡ and Takashi Kato*,† †

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Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan ‡ Department of Urban Engineering, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan S Supporting Information *

ABSTRACT: Here we report columnar liquid-crystalline (LC) nanostructured membranes that highly remove viruses and show sufficient water permeation. These membranes were prepared by employing two-component liquid crystals that exhibit tetragonal columnar phases. The membranes exhibited virus rejection values of >99.99% (log10 reduction value (LRV) > 4) and water flux ranging from 19 to 61 L m−2 h−1 (operation pressure: 0.3 MPa). These membranes were fabricated by photopolymerization of a fan-shaped diol molecule and imidazolium ionic liquid mixture, followed by subsequent removal of the ionic liquid. The rejection values and water flux depend on the fraction of ionic liquid. These results show new design strategies of materials for the water treatment nanostructured membranes that remove pathogens and contaminants.

T

rejection (log10 reduction value (LRV) > 6) of the virus bacteriophage Qβ (diameter: 25 nm).9 LRV is estimated by comparing the virus concentration in the feed and permeate solutions by the following equation

o obtain safe fresh water from natural seawater or brackish water, it is necessary to remove pathogens and salt.1 Membrane separation is prevalent in water purification and biopharmaceutical production processes because it is inexpensive and simple.2,3 Development of membranes with high separation performance is important for future applications.2,4,5 Many commercially available membranes use cross-linked aromatic polyamides and cellulose acetate derivatives.6,7 However, it is difficult to obtain well-defined pores with uniform diameters in these conventional membranes. Molecular self-organization methods such as thermotropic or lyotropic liquid crystals,8−13 copolymers,14−17 and carbon-based materials18,19 have emerged as solutions for fabricating membranes with well-controlled pore sizes. Here, we report the preparation of nanostructured liquidcrystalline (LC) columnar membranes with efficient virus removal and sufficient water flux by employing two-component liquid crystals consisting of 1 and 2 (Figure 1a and 1b). Liquid crystals exhibit both solid order and liquid fluidity. The fluidity of the liquid crystals allows for control of their orientation and formation of defectless and no pinhole structures. LC materials with nanosegregated structures have been applied in transport materials for energy-related fields20−23 and separation membranes for water treatment.8−13,24−32 Nanostructured membranes prepared from thermotropic ionic liquid crystals show selective salt rejection and high virus removal.8−10 In particular, nanostructured water treatment membranes prepared from a bicontinuous cubic (Cubbi) liquid crystal 3 (Figure 1c) showed >99.9999% © XXXX American Chemical Society

ij C yz LRV = log10jjjj f zzzz j Cp z k {

(1)

where Cp and Cf are the virus concentrations in the permeate and feed solution, respectively. LRV of the Cubbi membrane was very high, but this membrane also exhibited very low water flux ( 3).39 The virus rejection with RP1/2(x) decreased as the fraction of ionic liquid 2 increased. SEM observations of the top surface of RP1/2(x) revealed that more defects that were pinholes with diameter of 30 ± 10 nm were formed on the surface as x increased (Figure S8). To understand these results, the intercolumnar distances of these mixtures were estimated from the results of XRD measurements (Table S1). The intercolumnar distance of RP1/2(30) was 4.6 nm and was 0.1 nm smaller than that of 1/2(30). Similarly, the intercolumnar distances in RP1/2(40) and RP1/ 2(50) were 0.2 and 0.5 nm smaller than those in 1/2(40) and 1/2(50), respectively. These results suggest that the nanostructures shrink after the polymerization and removal of the ionic liquid from the membranes. Therefore, polymer films with more ionic liquid content may be more likely to suffer from the formation of defects of membranes, which are nanoscale pinholes. This leads to undesirable permeation of Qβ. The maximum virus rejection of RP1/2(30) (LRV = 4.4 ± 0.3) was lower than that of the Cubbi LC membranes prepared from 3 (Figure 1c) without any pretreatment such as pressurization.9 The LRV of 3(Cubbi) increased from about three to about five after 6 h (Figure 5a). This increase in the rejection properties has previously been explained by the effects of the pressurization which may change the morphology of the membrane channels.9 However, only a slight increase in LRV was observed with RP1/2(30). The average water flux of RP1/2(x) increased with the molar fraction of 2 (Table 1). This increase may occur because of the removal of a large amount of ionic liquid from the nanostructured LC membranes which would result in the formation of larger pores (see Supporting Information and Figure S6). The water fluxes for these membranes as a function of time showed different trends (Figure 5b). The average flux of RP1/2(30) was gradually increased over time. The small permeation channels may make it difficult for water molecules to enter initially. Pressurization of the membrane forces water molecules into the nanopores to create more hydrophilic conditions, which may make the wet channels more accessible for water molecules and increase the flux. The initial fluxes of RP1/2(40) and RP1/2(50) were higher than that of RP1/ 2(30). It is easier for water molecules to enter the channels in RP1/2(40) and RP1/2(50) because of the larger pore size. Over time, Qβ accumulated on the surfaces of RP1/2(40) and RP1/2(50), which led to a gradual decrease in water permeation. The magnitude of decrease of flux for only pure water is smaller than that of water containing virus (Figure S9). This observation suggests that virus deposition on the membranes is a major cause of the water flux reduction in the virus filtration tests. The average flux of RP1/2(30) over 4−6 h was 20 ± 6 L m−2 h−1, which was 40 times higher than that of 3(Cubbi) (0.54 ± 0.05 L m−2 h−1). This may be caused by differences in the hydrophilic channel diameters. The estimated diameter of channels for RP1/2(30) was 1.5 nm (Figure S10), and that for 3(Cubbi) was 0.6 nm.8,9 Large nanopores enhance the water molecule permeation. Although columnar liquid crystals have one-dimensional structures, the hydrophilic one-dimensional nanopores may not fully align perpendicularly. However, as we recently reported, efficient permeation of water was achieved

Figure 4. (a) Dependence of intercolumnar distances for 1/2(x) mixtures in the Colt phase on the mol % of ionic liquid 2. (b) The average number of compound 1 (n1) and ionic liquid 2 (n2) per crosssectional slice of the columns.

Table 1 represents the virus rejection values and the average flux over the total duration of experiment operated under 0.3 MPa. Figure 5 shows the progression of the average LRV (eq 1) and the average flux for the different membranes tested over 6 h. The virus rejection by RP1/2(30) was the highest among all tested RP1/2(x) membranes (x = 30, 40, and 50) (Table 1). Table 1. Rejection of Bacteriophage Qβ by the LC Nanostructured Membranes average flux [L m−2 h−1]b

virus rejectiona membrane RP1/2(30) RP1/2(40) RP1/2(50) 3(Cubbi)d

c

LRV

%

± ± ± ±

99.996 99.994 99.950 99.999

4.4 4.2 3.3 5.0

0.3 0.4 0.3 1.0

0−6 h 19 31 61 0.49

± ± ± ±

6 6 4 0.08

4−6 h 20 26 52 0.54

± ± ± ±

6 6 4 0.05

a Rejection over 4−6 h. bOperation pressure: 0.3 MPa. cThe mean value. dFrom ref 9.

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DOI: 10.1021/acsmacrolett.8b00821 ACS Macro Lett. 2019, 8, 24−30

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ACS Macro Letters

Figure 5. (a) Average log reduction values (LRVs) and (b) average water fluxes of RP1/2(30), RP1/2(40), RP1/2(50), and 3(Cubbi)9 versus time. Operation pressure: 0.3 MPa. Inset in (b) shows a magnified graph for 3(Cubbi).

ORCID

with columnar nanostructured membranes, indicating that a large fraction of hydrophilic nanopores in the columnar structures are connected in the membranes.10 Columnar LC thin films have short distances between their surfaces, which will decrease the possibility of the nanopores being discontinuous. Some columnar liquid crystals in thin films spontaneously formed vertically aligned structures.41,42 Measurements of the degree of orientation of the column were technically difficult because the nanostructured LC polymer layer of the membrane was too thin and the nonwoven fabric substrate was too rough to measure the materials. In conclusion, nanostructured LC virus filtration membranes with efficient flux were developed from a fan-shaped polymerizable molecule containing a diol moiety and an ionic liquid. Mixtures of the diol compound and imidazoliumbased ionic liquid in various mixing ratios formed columnar LC phases. The self-assembled columnar nanostructures of the mixtures were preserved by photopolymerization. The nanostructures were maintained even after removal of the ionic liquid from polymer films. The nanostructured LC membranes showed virus rejection properties with higher water fluxes than previously reported bicontinuous LC nanostructured membranes.9 In addition, the membrane separation properties were tunable by changing the molar ratios of ionic liquid. To the best of our knowledge, this is the first example of preparing permeation membranes based on two-component liquid crystals. This strategy will be useful in the design of LC materials for functional and selective filtration membranes with high water flux.

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Kazuma Hamaguchi: 0000-0002-6400-0742 Daniel Kuo: 0000-0002-1471-806X Miaomiao Liu: 0000-0001-6308-254X Takeshi Sakamoto: 0000-0001-6312-2249 Masafumi Yoshio: 0000-0002-1442-4352 Hiroyuki Katayama: 0000-0002-3429-9069 Takashi Kato: 0000-0002-0571-0883 Present Address §

Research Center for Functional Materials, National Institute for Materials Science, Namiki, Tsukuba, Ibaraki 305-0044, Japan. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work was supported by JST, CREST, JPMJCR1422. We would like to thank Toray Industries, Inc. for supplying polysulfone supporting membranes. We are also grateful to Ms. Rino Ichikawa for performing the SEM observations and to Dr. Monika Gupta for fruitful discussions. We thank Gabrielle David, Ph. D., from the Edanz Group (www.edanzediting. com/ac) for editing a draft of this manuscript.

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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsmacrolett.8b00821.

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REFERENCES

(1) Shannon, M. A.; Bohn, P. W.; Elimelech, M.; Georgiadis, J. G.; Marias, B. J.; Mayes, A. M. Science and Technology for Water Purification in the Coming Decades. Nature 2008, 452, 301−310. (2) Lively, R. P.; Sholl, D. S. From Water to Organics in Membrane Separations. Nat. Mater. 2017, 16, 276−279. (3) Van Reis, R.; Zydney, A. Membrane Separations in Biotechnology. Curr. Opin. Biotechnol. 2001, 12, 208−211. (4) Gin, D. L.; Noble, R. D. Designing the Next Generation of Chemical Separation Membranes. Science 2011, 332, 674−676. (5) Werber, J. R.; Osuji, C. O.; Elimelech, M. Materials for NextGeneration Desalination and Water Purification Membranes. Nat. Rev. Mater. 2016, 1, 16018. (6) Geise, G. M.; Lee, H.-S.; Miller, D. J.; Freeman, B. D.; McGrath, J. E.; Paul, D. R. Water Purification by Membranes: The Role of Polymer Science. J. Polym. Sci., Part B: Polym. Phys. 2010, 48, 1685− 1718. (7) Petersen, R. J. Composite Reverse Osmosis and Nanofiltration Membranes. J. Membr. Sci. 1993, 83, 81−150.

Detailed experimental procedures and materials characterization (PDF)

AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected]. *E-mail: [email protected]. 28

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ACS Macro Letters (8) Henmi, M.; Nakatsuji, K.; Ichikawa, T.; Tomioka, H.; Sakamoto, T.; Yoshio, M.; Kato, T. Self-Organized Liquid-Crystalline Nanostructured Membranes for Water Treatment: Selective Permeation of Ions. Adv. Mater. 2012, 24, 2238−2241. (9) Marets, N.; Kuo, D.; Torrey, J. R.; Sakamoto, T.; Henmi, M.; Katayama, H.; Kato, T. Highly Efficient Virus Rejection with SelfOrganized Membranes Based on a Crosslinked Bicontinuous Cubic Liquid Crystal. Adv. Healthcare Mater. 2017, 6, 1700252. (10) Sakamoto, T.; Ogawa, T.; Nada, H.; Nakatsuji, K.; Mitani, M.; Soberats, B.; Kawata, K.; Yoshio, M.; Tomioka, H.; Sasaki, T.; Kimura, M.; Henmi, M.; Kato, T. Development of Nanostructured Water Treatment Membranes Based on Thermotropic Liquid Crystals: Molecular Design of Sub-Nanoporous Materials. Adv. Sci. 2018, 5, 1700405. (11) Zhou, M.; Kidd, T. J.; Noble, R. D.; Gin, D. L. Supported Lyotropic Liquid-Crystal Polymer Membranes: Promising Materials for Molecular-Size-Selective Aqueous Nanofiltration. Adv. Mater. 2005, 17, 1850−1853. (12) Zhou, M.; Nemade, P. R.; Lu, X.; Zeng, X.; Hatakeyama, E. S.; Noble, R. D.; Gin, D. L. New Type of Membrane Material for Water Desalination Based on a Cross-Linked Bicontinuous Cubic Lyotropic Liquid Crystal Assembly. J. Am. Chem. Soc. 2007, 129, 9574−9575. (13) Carter, B. M.; Wiesenauer, B. R.; Hatakeyama, E. S.; Barton, J. L.; Noble, R. D.; Gin, D. L. Glycerol-Based Bicontinuous Cubic Lyotropic Liquid Crystal Monomer System for the Fabrication of Thin-Film Membranes with Uniform Nanopores. Chem. Mater. 2012, 24, 4005−4007. (14) Yamamoto, T.; Kimura, T.; Komura, M.; Suzuki, Y.; Iyoda, T.; Asaoka, S.; Nakanishi, H. Block Copolymer Permeable Membrane with Visualized High-Density Straight Channels of Poly(Ethylene Oxide). Adv. Funct. Mater. 2011, 21, 918−926. (15) Vannucci, C.; Taniguchi, I.; Asatekin, A. Nanoconfinement and Chemical Structure Effects on Permeation Selectivity of SelfAssembling Graft Copolymers. ACS Macro Lett. 2015, 4, 872−878. (16) Zhang, Y.; Mulvenna, R. A.; Qu, S.; Boudouris, B. W.; Phillip, W. A. Block Polymer Membranes Functionalized with Nanoconfined Polyelectrolyte Brushes Achieve Sub-Nanometer Selectivity. ACS Macro Lett. 2017, 6, 726−732. (17) Sadeghi, I.; Kronenberg, J.; Asatekin, A. Selective Transport through Membranes with Charged Nanochannels Formed by Scalable Self-Assembly of Random Copolymer Micelles. ACS Nano 2018, 12, 95−108. (18) Holt, J. K.; Park, H. G.; Wang, Y.; Stadermann, M.; Artyukhin, A. B.; Grigoropoulos, C. P.; Noy, A.; Bakajin, O. Fast Mass Transport Through Sub-2-Nanometer Carbon Nanotubes. Science 2006, 312, 1034−1037. (19) Abraham, J.; Vasu, K. S.; Williams, C. D.; Gopinadhan, K.; Su, Y.; Cherian, C. T.; Dix, J.; Prestat, E.; Haigh, S. J.; Grigorieva, I. V.; Carbone, P.; Geim, A. K.; Nair, R. R. Tunable Sieving of Ions Using Graphene Oxide Membranes. Nat. Nanotechnol. 2017, 12, 546−550. (20) Kato, T.; Yoshio, M.; Ichikawa, T.; Soberats, B.; Ohno, H.; Funahashi, M. Transport of Ions and Electrons in Nanostructured Liquid Crystals. Nat. Rev. Mater. 2017, 2, 17001. (21) Soberats, B.; Yoshio, M.; Ichikawa, T.; Taguchi, S.; Ohno, H.; Kato, T. 3D Anhydrous Proton-Transporting Nanochannels Formed by Self-Assembly of Liquid Crystals Composed of a Sulfobetaine and a Sulfonic Acid. J. Am. Chem. Soc. 2013, 135, 15286−15289. (22) Soberats, B.; Yoshio, M.; Ichikawa, T.; Zeng, X.; Ohno, H.; Ungar, G.; Kato, T. Ionic Switch Induced by a Rectangular-Hexagonal Phase Transition in Benzenammonium Columnar Liquid Crystals. J. Am. Chem. Soc. 2015, 137, 13212−13215. (23) Robertson, L. A.; Gin, D. L. Effect of an n-Alkoxy-2,4-hexadiene Polymerizable Tail System on the Mesogenic Properties and CrossLinking of Mono-Imidazolium-Based Ionic Liquid Crystal Monomers. ACS Macro Lett. 2016, 5, 844−848. (24) Bögels, G. M.; van Kuringen, H. P. C.; Shishmanova, I. K.; Voets, I. K.; Schenning, A. P. H. J.; Sijbesma, R. P. Selective Absorption of Hydrophobic Cations in Nanostructured Porous

Materials from Crosslinked Hydrogen-Bonded Columnar Liquid Crystals. Adv. Mater. Interfaces 2015, 2, 1500022. (25) Bögels, G. M.; Lugger, J. A. M.; Goor, O. J. G. M.; Sijbesma, R. P. Size-Selective Binding of Sodium and Potassium Ions in Nanoporous Thin Films of Polymerized Liquid Crystals. Adv. Funct. Mater. 2016, 26, 8023−8030. (26) Gracia, I.; Romero, P.; Serrano, J. L.; Barberá, J.; Omenat, A. Templated Nanoporous Membranes Based on Hierarchically SelfAssembled Materials. J. Mater. Chem. C 2017, 5, 2033−2042. (27) Feng, X.; Kawabata, K.; Kaufman, G.; Elimelech, M.; Osuji, C. O. Highly Selective Vertically Aligned Nanopores in Sustainably Derived Polymer Membranes by Molecular Templating. ACS Nano 2017, 11, 3911−3921. (28) Lugger, J. A. M.; Mulder, D. J.; Bhattacharjee, S.; Sijbesma, R. P. Homeotropic Self-Alignment of Discotic Liquid Crystals for Nanoporous Polymer Films. ACS Nano 2018, 12, 6714−6724. (29) Lee, H. K.; Lee, H.; Ko, Y. H.; Chang, Y. J.; Oh, N. K.; Zin, W. C.; Kim, O. Synthesis of a Nanoporous Polymer with Hexagonal Channels from Supramolecular Discotic Liquid Crystals. Angew. Chem., Int. Ed. 2001, 40, 2669−2671. (30) Ishida, Y.; Sakata, H.; Achalkumar, A. S.; Yamada, K.; Matsuoka, Y.; Iwahashi, N.; Amano, S.; Saigo, K. Guest-Responsive Covalent Frameworks by the Cross-Linking of Liquid-Crystalline Salts: Tuning of Lattice Flexibility by the Design of Polymerizable Units. Chem. - Eur. J. 2011, 17, 14752−14762. (31) Broer, D. J.; Bastiaansen, C. M. W.; Debije, M. G.; Schenning, A. P. H. J. Functional Organic Materials Based on Polymerized Liquid-Crystal Monomers: Supramolecular Hydrogen-Bonded Systems. Angew. Chem., Int. Ed. 2012, 51, 7102−7109. (32) Van Kuringen, H. P. C.; Eikelboom, G. M.; Shishmanova, I. K.; Broer, D. J.; Schenning, A. P. H. J. Responsive Nanoporous Smectic Liquid Crystal Polymer Networks as Efficient and Selective Adsorbents. Adv. Funct. Mater. 2014, 24, 5045−5051. (33) Shimura, H.; Yoshio, M.; Hoshino, K.; Mukai, T.; Ohno, H.; Kato, T. Noncovalent Approach to One-Dimensional Ion Conductors: Enhancement of Ionic Conductivities in Nanostructured Columnar Liquid Crystals. J. Am. Chem. Soc. 2008, 130, 1759−1765. (34) Ichikawa, T.; Yoshio, M.; Taguchi, S.; Kagimoto, J.; Ohno, H.; Kato, T. Co-Organisation of Ionic Liquids with Amphiphilic Diethanolamines: Construction of 3D Continuous Ionic Nanochannels through the Induction of Liquid−Crystalline Bicontinuous Cubic Phases. Chem. Sci. 2012, 3, 2001−2008. (35) Yamashita, A.; Yoshio, M.; Shimizu, S.; Ichikawa, T.; Ohno, H.; Kato, T. Columnar Nanostructured Polymer Films Containing Ionic Liquids in Supramolecular One-Dimensional Nanochannels. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 366−371. (36) Yamashita, A.; Yoshio, M.; Soberats, B.; Ohno, H.; Kato, T. Use of a Protic Salt for the Formation of Liquid-Crystalline ProtonConductive Complexes with Mesomorphic Diols. J. Mater. Chem. A 2015, 3, 22656−22662. (37) Matsushita, T.; Shirasaki, N.; Tatsuki, Y.; Matsui, Y. Investigating Norovirus Removal by Microfiltration, Ultrafiltration, and Precoagulation-Microfiltration Processes Using Recombinant Norovirus Virus-Like Particles and Real-Time Immuno-PCR. Water Res. 2013, 47, 5819−5827. (38) Langlet, J.; Gaboriaud, F.; Duval, J. F. L.; Gantzer, C. Aggregation and Surface Properties of F-Specific RNA Phages: Implication for Membrane Filtration Processes. Water Res. 2008, 42, 2769−2777. (39) Guidelines for Drinking-water Quality, 4th ed.; World Health Organization: Geneva, Switzerland, 2011. (40) Deng, F.; Reeder, Z. K.; Miller, K. M. 1,3-Bis(2’-Hydroxyethyl)imidazolium Ionic Liquids: Correlating Structure and Properties with Anion Hydrogen Bonding Ability. J. Phys. Org. Chem. 2014, 27, 2−9. (41) Jung, H. T.; Kim, S. O.; Ko, Y. K.; Yoon, D. K.; Hudson, S. D.; Percec, V.; Holerca, M. N.; Cho, W. D.; Mosier, P. E. Surface Order in Thin Films of Self-Assembled Columnar Liquid Crystals. Macromolecules 2002, 35, 3717−3721. 29

DOI: 10.1021/acsmacrolett.8b00821 ACS Macro Lett. 2019, 8, 24−30

Letter

ACS Macro Letters (42) Feng, X.; Nejati, S.; Cowan, M. G.; Tousley, M. E.; Wiesenauer, B. R.; Noble, R. D.; Elimelech, M.; Gin, D. L.; Osuji, C. O. Thin Polymer Films with Continuous Vertically Aligned 1 nm Pores Fabricated by Soft Confinement. ACS Nano 2016, 10, 150−158.

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