Biomimetic membrane for desalination and water reuse 4

81 Chapter Highly Permeable Aquaporin-embedded Biomimetic Membrane Featured with a Magnetic-aided Approach 5.1 Introduction Kumar and his co-workers firstly reconstituted AqpZ into the block-copolymer vesicles, which demonstrated great potential of AQP-based biomimetic membranes [38] Since then, several endeavors have been made to design the AQP-incorporated biomimetic membrane for various water purification applications, like forward osmosis[83-86], Nanofiltration [87, 119, 140, 141], and reverse osmosis [88, 142] Several efforts were made to fabricated AQP-reconstituted black lipid/polymer membrane [82-85, 142] or supported lipid bilayer [88, 143], but only limited progress has been made Wang et al covalently bond the AqpZ-embedded block-copolymer film onto a gold-coated track-etched film to form a pore-spanning membrane, and demonstrated the function of AqpZ in a forward osmosis setup for the first time [86] However, the mechanical stability of these thin films was not sufficient under normal FO or NF testing conditions when there is strong surface shear or high hydraulic pressure In recent works [87, 140], stability was largely improved by cross-linking the AqpZ-incorporated films with UV, and nanofiltration performance was investigated Nevertheless, the membrane selectivity of these membranes was well below expectation probably due to low AqpZ working efficiency in the membrane The challenge here is how to fabricate a stable and defect free membrane, and maximize the potential of AQP In the previous study, an AqoZ-embedded mixedmatrix membrane has been developed using the layer-by-layer (LbL) polyelectrolyte 82 adsorption method [141] The AqpZ-incorporated liposomes, which function as highly water permeable dispersed phase, have been embedded in a polyelectrolyte LbL matrix The negatively charged liposomes are protected with a PLL shell, which provides stability to the liposomes especially when they are embedded in the LbL films We also observed that the number of liposomes adsorbed on the membrane was closely related to the amount of charged lipids carried in the liposomes The membrane has been proven to be strong enough to endure bar hydraulic pressure and surface agitation However, the designed membrane suffered from a low liposome-embedding efficiency, and the maximum vesicular fraction in the membrane is only approximately 20% The aim of this work is to further improve the embedding efficiency of the AqpZincorporated vesicles in the membrane, by encapsulating magnetic nanoparticles (MNPs) into the vesicles and utilizing the magnetic force to accelerate the adsorption of the vesicles on the polyelectrolyte film The MNP-encapsulated liposomes, also named as magnetic liposomes, has been studied in drug delivery [144, 145], controlled release[146], or as contrast agents for magnetic resonance imaging [147] The surface modification of MNPs by hydrophilic molecules avoids aggregation and precipitation of the particles and allows a stable suspension in biological applications [148-150] The membrane fabrication process is schematically shown in Figure 5.1 On top of a negatively charged membrane substrate, PAH was firstly deposited to form a polycation layer, and a blend of PAA and PSS was then deposited to form a polyanion layer Afterward, driven by a strong magnet at the bottom of the 83 membrane, the PLL-encapsulated magnetic liposomes are precipitated onto the polyanion layer The liposome layer is further stabilized with another PSS/PAA layer to stabilize this mixed-matrix membrane The magnetic force-driven approach is effective and straightforward In this work, magnetic liposome characterization, membrane morphology study and forward osmosis performance of this biomimetic membrane are discussed Hydrolyzed PAN membrane Poly-L-lysine stabilized liposomes with Aquaporin Magnetic nanoparticles (MNPs) polyanion polycation Figure 5.1 The schematic presentation of fabrication procedures for the magnetic-aided LbL membrane 5.2 Experimental 5.2.1 Materials POPC, POPG, cholesterol and Rhodamine-PE were purchased from Avanti Polar Lipids Hydrochloric acid (HCl), sodium chloride (NaCl), magnesium chloride (MgCl2), sodium hydroxide (NaOH), sodium dodecyl sulfate (SDS), NMP, PLL, PAA, PSS, PAH, PMAA, and were products of Sigma-Aldrich (USA) Bio-Beads SM-2 absorbents and tris(hydroxymethyl) aminomethane (Tris) were purchased from BIO-RAD (USA) Polyacrylonitrile (PAN) for substrate preparation was obtained 84 from Tong-Hua Synthesis Fiber Co Ltd (Taiwan) A 10-histidine residual tagged AqpZ used in this work was obtained from Biochemistry department in National University of Singapore, and the synthesis of AqpZ followed the procedures in Borgnia et al’s work [37] Ultrapure water was produced by the Millipore Reference A+ system (Merck Millipore, USA) A 10 mM Tris buffer at pH=7.5 with 15 mM NaCl was used throughout this study 5.2.2 Magnetic nanoparticle synthesis Precursors were prepared by dissolving 40mmol iron chloride (FeCl3.6H2O) and 120mmol sodium oleate in a solvent mixture of 80mL ethanol, 60mL DI water and 140mL hexane Heated to 70 °C and kept for hours The complex was then separated from the solvent The MNPs were synthesized using the thermal decomposition method 2mmol complex, 2mmol oleic acid and 6mmol oleyl alcohol were dissolved in 10g diphenyl ether, heated to 250°C and kept for 30min Ligand exchanging was applied to graft PMAA on the surface of MNP 5.2.3 Magnetic liposome preparation 6.5mg POPC, 3mg POPG, and 0.5mg cholesterol were dissolved in chloroform 0.5 mole% Rhodamine-PE were added when necessary The dry lipid film was made by removing the chloroform using a rotary-evaporator, followed by overnight vacuum A 100µL MNP solution (40mg/mL) was added to swell the dry film before bulk rehydration by 2mL Tris Buffer Small unilamellar vesicles (SUV) with a uniform size were produced by extruding the suspension through a polycarbonate Nuclepore track-etch membrane (Whatman, UK) that had a pore size of 200 nm For AqpZ reconstitution experiments, an AqpZ stock solution was added during the film 85 rehydration step and the mixture was agitated for at least hours Bio-Beads were then added into the mixture stepwise to remove the detergent The suspension was protected with high purity argon throughout the experiment To remove the unencapsulated MNPs, a magnetic liposome suspension of 1mL was added into a 30mm x 200mm2 chromatography column filled with Sephadex G100 The suspension was eluted with Tris Buffer at a flow rate of 0.8mL/min The eluted sample was passed through a UV spectrometer and detected at the wavelength of 210nm Fractions of 2mL elution which corresponded to the magnetic liposomes were collected, while the rest of the eluted sample was discarded The collected magnetic liposomes were then stabilized with PLL according to the following procedures A 2mL liposome solution was added at equal volumes to a 0.5 mg/mL PLL solution in Tris buffer dropwise, while the PLL solution was stirred at a speed of 950 rpm The mixing process was completed within minutes The resultant solution was concentrated to 1mL using a 50mL centrifugal filter (100,000MWCO, Ultracel®, Millipore) A Zetasizer Nano ZS instrument (Malvern, UK) was employed to characterize the vesicle/nanoparticle size distribution 5.2.4 Field emission transmission electron microscopy (FETEM) Field emission transmission electron microscopy (JEOL, JEM-2100F, Japan) was used to investigate the MNPs and liposomes with and without MNP encapsulation Before imaging, the liposome solution was diluted to 0.5 mg/mL with Tris buffer and dropped on copper grids coated by an ultrathin carbon film for 15 and then rinsed 86 by ultrapure water dropwise The samples were air dried for 30 before the FETEM imaging 5.2.5 Liposome-embedded LbL membranes formation Flat sheet PAN substrates were prepared by casting an 18 wt% PAN/NMP solution directly on a Teflon plate using a 200 µm casting knife The membranes were then quickly immersed in a water bath to induce phase inversion and then soaked in deionized water overnight to remove all traces of NMP The PAN membranes were later hydrolyzed with a solution containing M NaOH for 1.5 hours at 45°C to generate negative charges on the membrane surface After the hydrolysis, the membrane was washed with excess volumes of ultrapure water and used within days To prepare the LbL membrane with magnetic liposomes, a PAH solution (1g/L) was first deposited onto the surface of the hydrolyzed PAN, followed by a PSS/PAA blend solution (1g/L) It took 20 to deposit each layer and the membrane was rinsed with ultrapure water three times after each deposition Next, the PLL-stabilized magnetic liposome suspension was deposited on the top surface of the membrane with a cubic magnet (0.7T, 80kgf) placed beneath the membrane for hour Finally, one more layer of PSS/PAA was deposited on top of the PLL-liposomes to stabilize the liposomes A membrane area of 78.5mm2 was prepared and used for further studies 87 5.2.6 Vesicle adsorption study by confocal Laser scanning microscope (CLSM) To study the vesicle adsorption process, a glass coverslip (12×12mm) was immersed consecutively in 2% Hellmanex solution (60°C), 0.01 M SDS solution, and 0.1 M HCl The glass coverslip was rinsed intensively with ultrapure water after 20 incubation in each solution Three bilayers of PAH-PSS/PAA were deposited onto the glass coverslip using the same method described above Then, the substrate was incubated with magnetic liposome solution for 15, 30, 45, or 60 in presence or absence of the magnetic field The glass coverslip was rinsed with Tris buffer to remove the unadsorbed liposomes before imaging The CLSM images were taken with a Nikon A1 confocal scanning system, equipped with 60× oil immersion lens The excitation laser was set at wavelength of 488 nm and emission was collected from 590 to 650 nm The obtained images were processed and analyzed using ImageJ 1.46r 5.2.7 Forward osmosis measurement The prepared membrane was placed in a FO testing cell with a draw solution chamber and a feed solution chamber at each side of the membrane The active layer of the membrane was facing the draw solution chamber in all the FO experiments Solutions of both sides flow co-currently through the cell at a flow rate of 30mL/min in the cross-flow mode The water flux Jw was calculated using the equation shown below !! = ∆! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(9) !! ∆! where ∆V is the volume change of the draw solution over a certain time ∆t, and Sm is the effective membrane surface area The salt reverse flux from the draw solution to the feed Js, was calculated from the increase in conductivity of the feed solution 88 !! = ∆!! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(10) !! ∆! where Vf is the volume of the feed and ∆Cf is the change of salt concentration in the feed The membrane was tested by using 0.3M sucrose as draw solution and 200 ppm NaCl as feed solution The conductivity of the draw solution is very close to DI water, which can be ignored Therefore, the membrane selectivity can be estimated with the following equation !"#"$%&'&%( = ! (∆!! − !!! !!! )/!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(11) !!! !!! /!! where Cd1 is the final salt concentration of the draw solution in g mL-1; Vd1 is the final volume of draw solution and initial volume of the feed, respectively, in mL The ΔWd is the weight increase of the draw solution, in g Mw and Ms are the molecular weights of water (18.02 g/mol) and NaCl (58.44 g/mol) , respectively 89 5.3 Results and discussion 5.3.1 Characterization of magnetic liposomes a b c Figure 5.2 The FETEM images of (a) free MNPs, (b) MNP-encapsulated liposomes and (c) intact liposomes Scale bar: 100nm The insert in (a) is the MNP size distribution measured by dynamic light scattering MNPs were synthesized using the thermal decomposition method and grafted with poly(methacrylic acid) (PMAA) The image taken by field emission transmission electron microscopy (FETEM) shows that the particle size ranges from to 5nm (Figure 5.2a), and a similar result is observed by dynamic light scattering (the Insert in Figure 5.2a) To produce the magnetic liposomes, a dry lipid film consisting of 90 POPC, POPG and mol% cholesterol were swelled with the MNP solution before conducting film rehydration Unilamellar vesicles with a uniform size were formed by extruding the magnetic liposome suspension through a 200nm polycarbonate Nuclepore track-etch membrane The encapsulated MNPs in the liposomes can be clearly observed from the FETEM images (Figure 5.2b), while the intact liposomes were shown as hollow spheres (Figure 5.2c) The osmotic water permeability of liposomes was studied using a stopped-flow light scattering apparatus Since an increase in light scattering signal corresponds to a reduction in vesicle size after the hypertonic osmotic shock, the osmotic permeability of the vesicles is directly related to the rate of increase in light scattering signal Figure 5.3a displays the normalized signals of magnetic liposomes with different AqpZ-to-lipid ratios The AqpZ incorporated vesicles have a much rapid increment in light scattering signal as compared to the control one In addition, the higher AqpZ content, the faster the signal response Similar to the intact liposomes (i.e., without the MNP encapsulation), the permeability of magnetic liposomes reaches the maximum at an AqpZ incorporation ratio of 2% (or at AqpZ-to-lipid weight ratio of 1:50) but declines at a higher incorporation ratio (Figure 5.3b) The AqpZ incorporated liposomes comprising MNPs exhibit 60-70% permeability of those intact liposomes There are two possible reasons One of them might be the formation of the MNP/AqpZ complex in the liposome suspension The other might be due to the presence of MNPs within liposomes The former arises from the fact that the PMAA grafted on the particle surface may entangle with AqpZ and prohibit its effective reconstitution As a result, the water permeability is reduced Similarly, the latter might delay the response of vesicles during the osmotic shock 100 membrane consisting of 2% AqpZ still reaches an impressive value of 21.8 Lm-2h-1 when the feed water contains 200ppm MgCl2 As the feed concentration increases, the water flux is reduced because of a lower osmotic driven force across the membrane and a stronger concentration polarization effect (Table 5.2) The selectivity of water to salt, which is estimated using the me, is more than 27000 The FO performance of the newly developed membrane is much better comparing with the previous works using sucrose as the draw solute [86, 151] Table 5.2 FO performance of the AqpZ-embedded membrane by using 0.3M sucrose as the draw solution and MgCl2 as the feed solution The active layer faces the draw solution 2% AqpZ LbL membrane Feed concentration MgCl2 Water flux (Lm-2h-1) Salt flux (gm-2h-1) Selectivity 200ppm 500ppm 1000ppm 21.8 17.2 15.4 2.4 2.7 47987 33653 27177 5.4 Conclusion In this study, we have developed an aquaporin-embedded biomimetic membrane by means of magnetic-driven vesicle precipitation and multilayer polyelectrolyte adsorption methods Aided with magnetic force, more liposomes can be adsorbed onto the membrane matrix, which directly enriches the number of AqpZs on the membrane surface and increases water flux up to 70% With this straightforward fabrication method, the newly developed biomimetic membrane shows superior water flux in a practical situation Future works will be aimed at the enhancements of membrane stability and water flux For example, it has been suggested that more AqpZs can be functionally incorporated in block copolymer vesicles than in lipid 101 vesicles [41] As a result, it is possible to replace the current liposomes by charged polymersomes which have better mechanical stability than liposomes Moreover, the stability of AqpZ embedded membranes may be improved with the aid of chemical cross-linking With these approaches, there could be great potentials to produce the new generation membrane for water purification 102 Chapter Conclusions and recommendations On the basis of the properties of exceptional water permeability and high solute rejection that possessed by AQP, several possible designs of this protein-based biomimetic membranes have been explored and investigated in this thesis To meet the challenges of fabricating the biomimetic membranes as defect-free, stable, scalable and high-AQP content, we started from exploring the possibility of using the LB technique to build-up the AQP-reconstituted lipid bilayer; then we devised an NF membrane immobilized with UV cross-linked proteoliposomes; and finally we developed the AQP-based mixed-matrix membrane based on the LbL method With these efforts, continuous progresses have been made to achieve the combination of improvements in both the membrane stability and the membrane performance Amongst our different designs, the AQP-embedded mixed-matrix membrane fabricated using the polyelectrolyte LbL self-assembly approach demonstrated the best NF performance, with a PWP of approximately L m-2 h-1 bar-1, and a salt rejection of upto 96% Being enhanced by magnetic forces, the AQP-embedded mixed-matrix membranes have shown impressive FO performances Several advantages of this mixed-matrix membrane design can be identified: (1) the relatively impermeable matrix eliminates or reduces the defects in the inter-liposome area so that water molecules are more easily transported through the AqpZ channels; (2) the AqpZ-incorporated liposomes behave as a highly permeable dispersed phase that increases the overall permeability of the membrane; (3) the properties of both continuous and dispersed phases can be tuned by selection of the polyelectrolytes and fabrication of liposomes, respectively The LbL method makes the production of the AQP-based biomimetic membranes more efficient and also opens up the possibility of large-scale fabrication 103 Even though the our membranes are able to sustain a hydraulic pressure of up to bar in NF tests, as well as the tangential flow in FO tests, the overall membrane stability still does not qualify for industrial applications Further enhancement in membrane stability is definitely necessary in order to satisfy the long-term needs for water purification Therefore, a few recommendations are proposed for future investigations: 1) Block copolymer vesicles have been proven to be more robust than lipid vesicles, and it has been suggested that more AqpZs can be functionally incorporated in block copolymer vesicles than in lipid vesicles Thus, if liposomes could be replaced by polymersomes in our biomimetic membrane designs, both the functionality and the stability of the membrane could be potentially improved To achieve that, the block copolymer synthesis, which determines the material quality as well as the capability of protein reconstitution, must be strictly controlled 2) Introducing chemical cross-linking to the membrane selective layer can largely improve the membrane stability Because the current mixed-matrix biomimetic membrane is purely based on the electrostatic interactions between each layer, the membrane may be decomposed in long-term vigorous testing conditions We could overcome this issue by either applying the chemical bonding between the liposome and the polyelectrolyte layer, or introducing chemical crosslinking on the entire LbL film 104 In longer term, when this new generation membranes are well developed for desalination and water reuse, new challenges will be emerged related to the membrane operation and commercialization These may include minimizing the membrane fouling, developing membrane cleaning process, minimizing the concentration polarization effect, as well as reducing the AQP production cost In this sense, we are only making a small step in the journey of biomimetic membrane fabrication for desalination and water reuse 105 APPENDICES Journal Publications • • • • G Sun, H Zhou, Y Li, K Jeyaseelan, A Armugam and T S Chung A novel method of AquaporinZ incorporation via binary-lipid Langmuir monolayers Colloids Surf B Biointerfaces, 2012, 89, 283-288 G Sun, K Jeyaseelan, A Armugam and T S Chung Stabilization and immobilization of aquaporin reconstituted lipid vesicles for water purification Colloids Surf B Biointerfaces, 2013, 102, 466– 471 G Sun, K Jeyaseelan, A Armugam and T S Chung A Layer-by-Layer selfassembly approach to developing an aquaporin-embedded mixed matrix membrane RSC Adv., 2013, 3, 473-481 G Sun, T S Chung, N Chen, X Lu, Q Zhao Highly permeable aquaporinembedded biomimetic membrane featured with a magnetic-aided approach RSC Adv., 2013, 3, 9178-9184.! 106 REFERENCES [1] D.R Paul, Reformulation of the solution-diffusion theory of reverse osmosis, J Membrane Sci, 241 (2004) 371 [2] N Kaushik, Membrane Separation Processes, in, PHI Learning Pvt Ltd, 2008 [3] H.K Lonsdale, U Merten, R.L Riley, Transport properties of cellulose acetate osmotic membranes, Journal of Applied Polymer Science, (1965) 1341-1362 [4] S Loeb, S Sourirajan, Sea water demineralization by means of an osmotic membrane, , Advances in Chemistry, 38 (1963) 117-132 [5] J.A Nollet, Lecons de physique-experimentale, Hippolyte-Louis Guerin, Paris, 1748 [6] J.H van't Hoff, Die Rolle des osmotischen Druckes in der Analogie zwischen Lösungen und Gasen, Z Phys Chem., (1887) 481-508 [7] K.L Lee, R.W Baker, H.K Lonsdale, Membranes for power generation by pressure-retarded osmosis, J Membrane Sci, (1981) 141–171 [8] M Williams, D Bhattacharyya, R Ray, S McCray, Membrane Handbook, Van Nostrand Reinhold, New York, 1992 [9] P Canepa, N Marignetti, U Rognoni, S Calgari, Olive Mills Wastewater Treatment by Combined Membrane Processes, Water Research, 22 (1988) 1491 [10] P.S Cartwright, Membranes separations technology for industrial effluent treatment - a review, Desalination, 56 (1985) 17 [11] L.F Greenlee, D.F Lawler, B.D Freeman, B Marrot, P Moulin, - 43 (2009) 2348 [12] P Eriksson, Nanofiltration extends the range of membrane filtration, Environ Prog., (1988) 58-62 [13] A Lhassani, M Rumeau, D Benjelloun, M Pontie, Selective demineralization of water by nanofiltration application to the defluorination of brackish water, Water Research, 35 (2001) 3260-3264 [14] B Van der Bruggen, M Manttari, M Nystrom, Drawbacks of applying nanofiltration and how to avoid them, Separation and Purification Technology, 63 (2008) 251–263 [15] M Elimelech, W.A Phillip, The Future of Seawater Desalination: Energy, Technology, and the Environment, Science, 333 (2011) 712-717 [16] T.Y Cath, A.E Childress, M Elimelech, Forward osmosis: Principles, applications, and recent developments, J Membrane Sci, 281 (2006) 70-87 [17] R.E Kravath, J.A Davis, Desalination of Sea-Water by Direct Osmosis, Desalination, 16 (1975) 151-155 [18] J.E Cadotte, L.T Rozelle, In-situ-formed condensation of polymers for reverse osmosis membranes, OSW PB-Report, (1972) 927 [19] C Fritzmann, J Lowenberg, T Wintgens, T Melin, State-of-the-art of reverse osmosis desalination, Desalination, 216 (2007) 1-76 [20] R Semiat, Energy Issues in Desalination Processes, Environ Sci Technol, 42 (2008) 8193-8201 [21] M Busch, W.E Mickols, Reducing energy consumption in seawater desalination, Desalination, 165 (2004) 299-312 [22] J.A Thomas, A.J.H McGaughey, O Kuter-Arnebeck, Pressure-driven water flow through carbon nanotubes: Insights from molecular dynamics simulation, International Journal of Thermal Sciences, 49 (2010) 281-289 107 [23] G Hummer, J.C Rasaiah, J.P Noworyta, Water conduction through the hydrophobic channel of a carbon nanotube, Nature, 414 (2001) 188-190 [24] A Kalra, S Garde, G Hummer, Osmotic water transport through carbon nanotube membranes, P Natl Acad Sci USA, 100 (2003) 10175-10180 [25] S Joseph, N.R Aluru, Why are carbon nanotubes fast transporters of water?, Nano Letters, (2008) 452-458 [26] S Kar, R.C Bindal, P.K Tewari, Carbon nanotube membranes for desalination and water purification: Challenges and opportunities, Nano Today, (2012) 385-389 [27] B Corry, Designing carbon nanotube membranes for efficient water desalination, J Phys Chem B, 112 (2008) 1427-1434 [28] G.M Preston, P Agre, Isolation of the Cdna for Erythrocyte Integral MembraneProtein of 28-Kilodaltons - Member of an Ancient Channel Family, P Natl Acad Sci USA, 88 (1991) 11110-11114 [29] B.L Smith, P Agre, Erythrocyte Mr-28,000 Transmembrane Protein Exists as a Multisubunit Oligomer Similar to Channel Proteins, J Biol Chem, 266 (1991) 64076415 [30] G.M Preston, T.P Carroll, W.B Guggino, P Agre, Appearance of Water Channels in Xenopus Oocytes Expressing Red-Cell Chip28 Protein, Science, 256 (1992) 385-387 [31] S Sasaki, Introduction for special issue for aquaporin - Expanding the world of aquaporins: new members and new functions, Pflugers Arch., 456 (2008) 647-649 [32] W Park, B.E Scheffler, P.J Bauer, B.T Campbell, Identification of the family of aquaporin genes and their expression in upland cotton (Gossypium hirsutum L.), Bmc Plant Biology, 10 (2010) [33] T Gonen, T Walz, The structure of aquaporins, Q Rev Biophys, 39 (2006) 361396 [34] J.B Heymann, A Engel, Aquaporins: Phylogeny, structure, and physiology of water channels, News in Physiological Sciences, 14 (1999) 187-193 [35] U Johanson, M Karlsson, I Johansson, S Gustavsson, S Sjovall, L Fraysse, A.R Weig, P Kjellbom, The complete set of genes encoding major intrinsic proteins in arabidopsis provides a framework for a new nomenclature for major intrinsic proteins in plants, Plant Physiology, 126 (2001) 1358-1369 [36] P Agre, Aquaporin water channels in kidney, J Am Soc Nephrol, 11 (2000) 764777 [37] M.J Borgnia, D Kozono, G Calamita, P.C Maloney, P Agre, Functional reconstitution and characterization of AqpZ, the E-coli water channel protein, J Mol Biol, 291 (1999) 1169-1179 [38] M Kumar, M Grzelakowski, J Zilles, M Clark, W Meier, Highly permeable polymeric membranes based on the incorporation of the functional water channel protein Aquaporin Z, Proc Natl Acad Sci U S A, 104 (2007) 20719-20724 [39] A.S Verkman, A.K Mitra, Structure and function of aquaporin water channels, American Journal of Physiology-Renal Physiology, 278 (2000) F13-F28 [40] J.S Jung, G.M Preston, B.L Smith, W.B Guggino, P Agre, MolecularStructure of the Water Channel through Aquaporin Chip - the Hourglass Model, J Biol Chem, 269 (1994) 14648-14654 [41] M Kumar, M Payne, S.K Poust, J.L Zilles, Polymer-based biomimetic membranes for desalination, in: C.H Nielsen (Ed.) Biomimetic membranes for sensor and separation applications, Springer, 2012 108 [42] D Kozono, M Yasui, L.S King, P Agre, Aquaporin water channels: atomic structure and molecular dynamics meet clinical medicine, Journal of Clinical Investigation, 109 (2002) 1395-1399 [43] K Murata, K Mitsuoka, T Hirai, T Walz, P Agre, J.B Heymann, A Engel, Y Fujiyoshi, Structural determinants of water permeation through aquaporin-1, Nature, 407 (2000) 599-605 [44] C.H Nielsen, Major Intrinsic Proteins in Biomimetic Membranes, in: Mips and Their Role in the Exchange of Metalloids, 2010, pp 127-142 [45] G Calamita, W.R Bishai, G.M Preston, W.B Guggino, P Agre, MolecularCloning and Characterization of Aqpz, a Water Channel from Escherichia-Coli, J Biol Chem, 270 (1995) 29063-29066 [46] J.Z Lian, S.H Ding, J Cai, D.P Zhang, Z.N Xu, X.N Wang, Improving aquaporin Z expression in Escherichia coli by fusion partners and subsequent condition optimization, Applied Microbiology and Biotechnology, 82 (2009) 463470 [47] B.X Yang, A.N vanHoek, A.S Verkman, Very high single channel water permeability of aquaporin-4 in baculovirus-infected insect cells and liposomes reconstituted with purified aquaporin-4, Biochemistry-Us, 36 (1997) 7625-7632 [48] P.J.L Werten, L Hasler, J.B Koenderink, C.H.W Klaassen, W.J de Grip, A Engel, P.M.T Deen, Large-scale purification of functional recombinant human aquaporin-2, Febs Letters, 504 (2001) 200-205 [49] G Fischer, U Kosinska-Eriksson, C Aponte-Santamaria, M Palmgren, C Geijer, K Hedfalk, S Hohmann, B.L de Groot, R Neutze, K Lindkvist-Petersson, Crystal Structure of a Yeast Aquaporin at 1.15 angstrom Reveals a Novel Gating Mechanism, Plos Biology, (2009) [50] M Karlsson, D Fotiadis, S Sjovall, I Johansson, K Hedfalk, A Engel, P Kjellbom, Reconstitution of water channel function of an aquaporin overexpressed and purified from Pichia pastoris, Febs Letters, 537 (2003) 68-72 [51] F Oberg, M Ekvall, M Nyblom, A Backmark, R Neutze, K Hedfalk, Insight into factors directing high production of eukaryotic membrane proteins; production of 13 human AQPs in Pichia pastoris, Molecular Membrane Biology, 26 (2009) 215U211 [52] R.P Richter, J.L.K Him, A Brisson, Supported lipid membranes, Materials Today, (2003) 32-37 [53] R.P Richter, R Berat, A.R Brisson, Formation of solid-supported lipid bilayers: An integrated view, Langmuir, 22 (2006) 3497-3505 [54] E.T Castellana, P.S Cremer, Solid supported lipid bilayers: From biophysical studies to sensor design, Surf Sci Rep, 61 (2006) 429-444 [55] D.K Martin, Nanobiotechnology of biomimetic membranes, Springer, New York, 2007 [56] P Mueller, D.O Rudin, H.T Tien, W.C Wescott, Reconstitution of Cell Membrane Structure in Vitro and Its Transformation into an Excitable System, Nature, 194 (1962) 979-& [57] I Langmuir, The mechanism of the surface phenomena of flotation, Transactions of the Faraday Society, 15 (1920) 0062-0074 [58] M.C Petty, Langmuir-Blodgett Films: An Introduction, Cambridge University Press, 1996 [59] A.P Girard-Egrot, L.J Blum, Langmuir-Blodgett technique for synthesis of biomimetic lipid membranes, in: D.K MARTIN (Ed.) Nanobiotechnology of Biomimetic Membranes, Springer, 2007 109 [60] E Kalb, S Frey, L.K Tamm, Formation of supported planar bilayers by fusion of vesicles to supported phospholipid monolayers, Biochim Biophys Acta, 1103 (1992) 307-316 [61] V Erokhin, L.A Feigin, Deposition and Investigation of Protein LangmuirBlodgett-Films, in: Polymeric Layers, 1991, pp 47-51 [62] A.A Brian, H.M McConnell, Allogeneic Stimulation of Cyto-Toxic T-Cells by Supported Planar Membranes, Proceedings of the National Academy of Sciences of the United States of America-Biological Sciences, 81 (1984) 6159-6163 [63] R Richter, A Mukhopadhyay, A Brisson, Pathways of lipid vesicle deposition on solid surfaces: A combined QCM-D and AFM study, Biophys J, 85 (2003) 30353047 [64] R.P Richter, A Brisson, QCM-D on mica for parallel QCM-D-AFM studies, Langmuir, 20 (2004) 4609-4613 [65] Y.H Kim, M.M Rahman, Z.L Zhang, N Misawa, R Tero, T Urisu, Supported lipid bilayer formation by the giant vesicle fusion induced by vesicle-surface electrostatic attractive interaction, Chem Phys Lett, 420 (2006) 569-573 [66] F Tokumasu, A.J Jin, G.W Feigenson, J.A Dvorak, Atomic force microscopy of nanometric liposome adsorption and nanoscopic membrane domain formation, Ultramicroscopy, 97 (2003) 217-227 [67] J Jass, T Tjarnhage, G Puu, From liposomes to supported, planar bilayer structures on hydrophilic and hydrophobic surfaces: An atomic force microscopy study, Biophys J, 79 (2000) 3153-3163 [68] E Reimhult, F Hook, B Kasemo, Intact vesicle adsorption and supported biomembrane formation from vesicles in solution: Influence of surface chemistry, vesicle size, temperature, and osmotic pressure, Langmuir, 19 (2003) 1681-1691 [69] P Lenz, C.M Ajo-Franklin, S.G Boxer, Patterned supported lipid bilayers and monolayers on poly(dimethylsiloxane), Langmuir, 20 (2004) 11092-11099 [70] S.A Glazier, D.J Vanderah, A.L Plant, H Bayley, G Valincius, J.J Kasianowicz, Reconstitution of the pore-forming toxin alpha-hemolysin in phospholipid/18-octadecyl-1-thiahexa(ethylene oxide) and phospholipid/noctadecanethiol supported bilayer membranes, Langmuir, 16 (2000) 10428-10435 [71] H Hillebrandt, G Wiegand, M Tanaka, E Sackmann, High electric resistance polymer/lipid composite films on indium-tin-oxide electrodes, Langmuir, 15 (1999) 8451-8459 [72] T Baumgart, A Offenhausser, Polysaccharide-supported planar bilayer lipid model membranes, Langmuir, 19 (2003) 1730-1737 [73] G Elender, M Kuhner, E Sackmann, Functionalisation of Si/SiO2 and glass surfaces with ultrathin dextran films and deposition of lipid bilayers, Biosensors & Bioelectronics, 11 (1996) 565-577 [74] C Ma, M.P Srinivasan, A.J Waring, R.I Lehrer, M.L Longo, P Stroeve, Supported lipid bilayers lifted from the substrate by layer-by-layer polyion cushions on self-assembled monolayers, Colloid Surface B, 28 (2003) 319-329 [75] R Kugler, W Knoll, Polyelectrolyte-supported lipid membranes, Bioelectrochemistry, 56 (2002) 175-178 [76] A Janshoff, C Steinem, Transport across artificial membranes - an analytical perspective, Analytical and Bioanalytical Chemistry, 385 (2006) 433-451 [77] D.E Discher, A Eisenberg, Polymer vesicles, Science, 297 (2002) 967-973 [78] L.F Zhang, A Eisenberg, Multiple Morphologies of Crew-Cut Aggregates of Polystyrene-B-Poly(Acrylic Acid) Block-Copolymers, Science, 268 (1995) 17281731 110 [79] A Graff, M Winterhalter, W Meier, Nanoreactors from polymer-stabilized liposomes, Langmuir, 17 (2001) 919-923 [80] W Meier, C Nardin, M Winterhalter, Reconstitution of channel proteins in (polymerized) ABA triblock copolymer membranes, Angew Chem Int Edit, 39 (2000) 4599-+ [81] D Ho, B Chu, H Lee, C.D Montemagno, Protein-driven energy transduction across polymeric biomembranes, Nanotechnology, 15 (2004) 1084-1094 [82] J.S Hansen, M Perry, J Vogel, T Vissing, C.R Hansen, O Geschke, J Emneus, C.H Nielsen, Development of an automation technique for the establishment of functional lipid bilayer arrays, J Micromech Microeng, 19 (2009) [83] M.R Lander, S Ibragimova, C Rein, J Vogel, K Stibius, O Geschke, M Perry, C Helix-Nielsen, Biomimetic Membrane Arrays on Cast Hydrogel Supports, Langmuir, 27 (2011) 7002-7007 [84] J Vogel, M Perry, J.S Hansen, P.Y Bolinger, C.H Nielsen, O Geschke, A support structure for biomimetic applications, J Micromech Microeng, 19 (2009) [85] S Ibragimova, K Stibius, P Szewczykowski, M Perry, H Bohr, C HelixNielsen, Hydrogels for in situ encapsulation of biomimetic membrane arrays, Polym Advan Technol, 23 (2012) 182-189 [86] H.L Wang, T.S Chung, Y.W Tong, K Jeyaseelan, A Armugam, Z.C Chen, M.H Hong, W Meier, Highly Permeable and Selective Pore-Spanning Biomimetic Membrane Embedded with Aquaporin Z, Small, (2012) 1185-1190 [87] P.S Zhong, T.S Chung, K Jeyaseelan, A Armugam, Aquaporin-embedded biomimetic membranes for nanofiltration, J Membrane Sci, 407 (2012) 27-33 [88] Y Kaufman, A Berman, V Freger, Supported Lipid Bilayer Membranes for Water Purification by Reverse Osmosis, Langmuir, 26 (2010) 7388-7395 [89] C.H Nielsen, Biomimetic membranes for sensor and separation applications, Analytical and Bioanalytical Chemistry, 395 (2009) 697-718 [90] C.D Montemagno, Biomimetic Membrane Formed from a Vesicle-Thread Conjugate, in: W.I.P Organization (Ed.), 2011 [91] C.D Montemagno, C Bhatt, J Yi, T Stenstroem, Nanofabricated Membrane Using Polymerized Proteoliposomes, in: W.I.P Organization (Ed.), 2010 [92] C.W McConlogue, D Malamud, T.K Vanderlick, Interaction of DPPC monolayers with soluble surfactants: electrostatic effects of membrane perturbants, Bba-Biomembranes, 1372 (1998) 124-134 [93] P Fontaine, M.C Faure, F Muller, M Poujade, J.S Micha, F Rieutord, M Goldmann, Unexpected stability of phospholipid langmuir monolayers deposited on Triton X-100 aqueous solutions, Langmuir, 23 (2007) 12959-12965 [94] C.A Alves, E.L Smith, M.D Porter, Atomic Scale Imaging of Alkanethiolate Monolayers at Gold Surfaces with Atomic Force Microscopy, J Am Chem Soc, 114 (1992) 1222-1227 [95] S Alexandre, V Dérue, J.-M Valleton, F Sommer, T.-M Duc, High resolution imaging of lipid/protein Langmuir-Blodgett films by atomic force microscopy, Colloids and Surfaces B: Biointerfaces, 23 (2002) 183-189 [96] H Alpes, K Allmann, H Plattner, J Reichert, R Riek, S Schulz, Formation of Large Unilamellar Vesicles Using Alkyl Maltoside Detergents, Biochimica Et Biophysica Acta, 862 (1986) 294-302 [97] J.M Crane, G Putz, S.B Hall, Persistence of phase coexistence in disaturated phosphatidylcholine monolayers at high surface pressures, Biophys J, 77 (1999) 3134-3143 111 [98] D Levy, G Mosser, O Lambert, G.S Moeck, D Bald, J.L Rigaud, Twodimensional crystallization on lipid layer: A successful approach for membrane proteins, J Struct Biol, 127 (1999) 44-52 [99] X.M Li, M.M Momsen, J.M Smaby, H.L Brockman, R.E Brown, Cholesterol decreases the interfacial elasticity and detergent solubility of sphingomyelins, Biochemistry-Us, 40 (2001) 5954-5963 [100] S Morandat, K El Kirat, Membrane resistance to Triton X-100 explored by real-time atomic force microscopy, Langmuir, 22 (2006) 5786-5791 [101] E.D Goddard, K.P Ananthapadmanabhan, Interaction of Surfactants With Polymers and Proteins, CRC Press, Boca Raton, FL, 1993 [102] H Ritacco, D.H Kurlat, Critical aggregation concentration in the PAMPS(10%)/DTAB system, Colloid Surface A, 218 (2003) 27-45 [103] N Jain, S Trabelsi, S Guillot, D McLouglilin, D Langevin, P Letellier, M Turmine, Critical aggregation concentration in mixed solutions of anionic polyelectrolytes and cationic surfactants, Langmuir, 20 (2004) 8496-8503 [104] N Deo, S Jockusch, N.J Turro, P Somasundaran, Surfactant interactions with zein protein, Langmuir, 19 (2003) 5083-5088 [105] K Sahu, D Roy, S.K Mondal, R Karmakar, K Bhattacharyya, Study of protein-surfactant interaction using excited state proton transfer, Chem Phys Lett, 404 (2005) 341-345 [106] S Scheuring, P Ringler, M Borgnia, H Stahlberg, D.J Muller, P Agre, A Engel, High resolution AFM topographs of the Escherichia coli water channel aquaporin Z, Embo J, 18 (1999) 4981-4987 [107] D Miller, K Charalambous, D Rotem, S Schuldiner, P Curnow, P.J Booth, In vitro Unfolding and Refolding of the Small Multidrug Transporter EmrE, J Mol Biol, 393 (2009) 815-832 [108] T Surrey, F Jahnig, Refolding and Oriented Insertion of a Membrane-Protein into a Lipid Bilayer, P Natl Acad Sci USA, 89 (1992) 7457-7461 [109] T.D Sells, D.F Obrien, 2-Dimensional Polymerization of Lipid Bilayers Degree of Polymerization of Acryloyl Lipids, Macromolecules, 27 (1994) 226-233 [110] J.F.P.D Gomes, A.F.P Sonnen, A Kronenberger, J Fritz, M.A.N Coelho, D Fournier, C Fournier-Noel, M Mauzac, M Winterhalter, Stable polymethacrylate nanocapsules from ultraviolet light-induced template radical polymerization of unilamellar liposomes, Langmuir, 22 (2006) 7755-7759 [111] Z.L Cheng, G.D D'Ambruoso, C.A Aspinwall, Stabilized porous phospholipid nanoshells, Langmuir, 22 (2006) 9507-9511 [112] H Lee, S.M Dellatore, W.M Miller, P.B Messersmith, Mussel-inspired surface chemistry for multifunctional coatings, Science, 318 (2007) 426-430 [113] P Vermette, H.J Griesser, P Kambouris, L Meagher, Characterization of surface-immobilized layers of intact liposomes, Biomacromolecules, (2004) 14961502 [114] F Albertorio, A.J Diaz, T.L Yang, V.A Chapa, S Kataoka, E.T Castellana, P.S Cremer, Fluid and air-stable lipopolymer membranes for biosensor applications, Langmuir, 21 (2005) 7476-7482 [115] D.W Deamer, J Bramhall, Permeability of Lipid Bilayers to Water and Ionic Solutes, Chem Phys Lipids, 40 (1986) 167-188 [116] A.I Schäfer, A.G Fane, T.D Waite, Nanofiltration: principles and applications, in, Elsevier Ltd., Oxford, 2005 [117] H Wang, T.S Chung, Y.W Tong, W Meier, Z Chen, M Hong, K Jeyaseelan, A Armugam, Preparation and characterization of pore-suspending 112 biomimetic membranes embedded with Aquaporin Z on carboxylated polyethylene glycol polymer cushion, Soft Matter, (2011) 7274-7280 [118] G Sun, H Zhou, Y Li, K Jeyaseelan, A Armugam, T.S Chung, A novel method of AquaporinZ incorporation via binary-lipid Langmuir monolayers, Colloids Surf B Biointerfaces, 89 (2012) 283-288 [119] P.H.H Duong, T.S Chung, K Jeyaseelan, A Armugam, Z.C Chen, J Yang, M.H Hong, Planar biomimetic aquaporin-incorporated triblock copolymer membranes on porous alumina supports for nanofiltration, J Membrane Sci, 409 (2012) 34-43 [120] R.J Pei, X.Q Cui, X.R Yang, E.K Wang, Assembly of alternating polycation and DNA multilayer films by electrostatic layer-by-layer adsorption, Biomacromolecules, (2001) 463-468 [121] N Jessel, F Atalar, P Lavalle, J Mutterer, G Decher, P Schaaf, J.C Voegel, J Ogier, Bioactive coatings based on a polyelectrolyte multilayer architecture functionalized by embedded proteins, Adv Mater, 15 (2003) 692-695 [122] Y Lvov, K Ariga, I Ichinose, T Kunitake, Assembly of Multicomponent Protein Films by Means of Electrostatic Layer-by-Layer Adsorption, J Am Chem Soc, 117 (1995) 6117-6123 [123] N.A Kotov, I Dekany, J.H Fendler, Layer-by-Layer Self-Assembly of Polyelectrolyte-Semiconductor Nanoparticle Composite Films, J Phys Chem-Us, 99 (1995) 13065-13069 [124] M Michel, Y Arntz, G Fleith, J Toquant, Y Haikel, J.C Voegel, P Schaaf, V Ball, Layer-by-layer self-assembled polyelectrolyte multilayers with embedded liposomes: Immobilized submicronic reactors for mineralization, Langmuir, 22 (2006) 2358-2364 [125] D Volodkin, Y Arntz, P Schaaf, H Moehwald, J.C Voegel, V Ball, Composite multilayered biocompatible polyelectrolyte films with intact liposomes: stability and temperature triggered dye release, Soft Matter, (2008) 122-130 [126] D.V Volodkin, P Schaaf, H Mohwald, J.C Voegel, V Ball, Effective embedding of liposomes into polyelectrolyte multilayered films: the relative importance of lipid-polyelectrolyte and interpolyelectrolyte interactions, Soft Matter, (2009) 1394-1405 [127] J.F.P.D Gomes, A Rank, A Kronenberger, J Fritz, M Winterhalter, Y Ramaye, Polyelectrolyte-Coated Unilamellar Nanometer-Sized Magnetic Liposomes, Langmuir, 25 (2009) 6793-6799 [128] M Michel, D Vautier, J.C Voegel, P Schaaf, V Ball, Layer by layer selfassembled polyelectrolyte multilayers with embedded phospholipid vesicles, Langmuir, 20 (2004) 4835-4839 [129] C.S Shan, H.F Yang, D.X Han, Q.X Zhang, A Ivaska, L Niu, WaterSoluble Graphene Covalently Functionalized by Biocompatible Poly-L-lysine, Langmuir, 25 (2009) 12030-12033 [130] A Quinn, G.K Such, J.F Quinn, F Caruso, Polyelectrolyte blend multilayers: A versatile route to engineering interfaces and films, Adv Funct Mater, 18 (2008) 1726 [131] A Quinn, E Tjipto, A.M Yu, T.R Gengenbach, F Caruso, Polyelectrolyte blend multilayer films: Surface morphology, wettability, and protein adsorption characteristics, Langmuir, 23 (2007) 4944-4949 [132] K Hoffmann, T Friedrich, B Tieke, Layer-by-Layer Assembled Polyelectrolyte Blend Membranes and Their Use for Ion Separation and Rejection, Polym Eng Sci, 51 (2011) 1497-1506 113 [133] M Mulder, Basic principles of membrane technology, 2nd ed., Kluwer Academic, Dordrecht ; Boston, 1996 [134] J.M Berg, J.L Tymoczko, L Stryer, Biochemistry, in, New York: W H Freeman, 2002 [135] Q Saren, C.Q Qiu, C.Y.Y Tang, Synthesis and Characterization of Novel Forward Osmosis Membranes based on Layer-by-Layer Assembly, Environ Sci Technol, 45 (2011) 5201-5208 [136] H Sies, Glutathione and its role in cellular functions, Free Radical Bio Med, 27 (1999) 916-921 [137] S.P Sun, K.Y Wang, D Rajarathnam, T.A Hatton, T.S Chung, Polyamideimide Nanofiltration Hollow Fiber Membranes with Elongation-Induced Nano-Pore Evolution, Aiche J, 56 (2010) 1481-1494 [138] J.P Richie, The Role of Glutathione in Aging and Cancer, Exp Gerontol, 27 (1992) 615-626 [139] D.M Townsend, K.D Tew, H Tapiero, The importance of glutathione in human disease, Biomed Pharmacother, 57 (2003) 145-155 [140] G Sun, T.S Chung, K Jeyaseelan, A Armugam, Stabilization and immobilization of aquaporin reconstituted lipid vesicles for water purification, Colloids Surf B Biointerfaces, 102C (2012) 466-471 [141] G Sun, T.S Chung, K Jeyaseelan, A Armugam, A layer-by-layer selfassembly approach to developing an aquaporin-embedded mixed matrix membrane, RSC Advances, (2013) 473-481 [142] Y Zhao, C.Q Qiu, X.S Li, A Vararattanavech, W.M Shen, J Torres, C Helix-Nielsen, R Wang, X Hu, A.G Fane, C.Y Tang, Synthesis of robust and highperformance aquaporin-based biomimetic membranes by interfacial polymerizationmembrane preparation and RO performance characterization, J Membrane Sci, 423 (2012) 422-428 [143] X.S Li, R Wang, C.Y Tang, A Vararattanavech, Y Zhao, J Torres, T Fane, Preparation of supported lipid membranes for aquaporin Z incorporation, Colloid Surface B, 94 (2012) 333-340 [144] S Jain, V Mishra, P Singh, P.K Dubey, D.K Saraf, S.P Vyas, RGDanchored magnetic liposomes for monocytes/neutrophils-mediated brain targeting, Int J Pharm, 261 (2003) 43-55 [145] A.A Kuznetsov, V.I Filippov, R.N Alyautdin, N.L Torshina, O.A Kuznetsov, Application of magnetic liposomes for magnetically guided transport of muscle relaxants and anti-cancer photodynamic drugs, J Magn Magn Mater, 225 (2001) 95-100 [146] S Nappini, F.B Bombelli, M Bonini, B Norden, P Baglioni, Magnetoliposomes for controlled drug release in the presence of low-frequency magnetic field, Soft Matter, (2010) 154-162 [147] M.S Martina, J.P Fortin, C Menager, O Clement, G Barratt, C GrabielleMadelmont, F Gazeau, V Cabuil, S Lesieur, Generation of superparamagnetic liposomes revealed as highly efficient MRI contrast agents for in vivo imaging, J Am Chem Soc, 127 (2005) 10676-10685 [148] J Giri, S.G Thakurta, J Bellare, A.K Nigam, D Bahadur, Preparation and characterization of phospholipid stabilized uniform sized magnetite nanoparticles, J Magn Magn Mater, 293 (2005) 62-68 [149] A.K Gupta, M Gupta, Synthesis and surface engineering of iron oxide nanoparticles for biomedical applications, Biomaterials, 26 (2005) 3995-4021 114 [150] T Neuberger, B Schopf, H Hofmann, M Hofmann, B von Rechenberg, Superparamagnetic nanoparticles for biomedical applications: Possibilities and limitations of a new drug delivery system, J Magn Magn Mater, 293 (2005) 483-496 [151] J.C Su, T.S Chung, B.J Helmer, J.S de Wit, Enhanced double-skinned FO membranes with inner dense layer for wastewater treatment and macromolecule recycle using Sucrose as draw solute, J Membrane Sci, 396 (2012) 92-100 ... robust and highperformance aquaporin-based biomimetic membranes by interfacial polymerizationmembrane preparation and RO performance characterization, J Membrane Sci, 42 3 (2012) 42 2 -42 8 [ 143 ] X.S... (2007) 49 44- 4 949 [132] K Hoffmann, T Friedrich, B Tieke, Layer-by-Layer Assembled Polyelectrolyte Blend Membranes and Their Use for Ion Separation and Rejection, Polym Eng Sci, 51 (2011) 149 7-1506... J.L Zilles, Polymer-based biomimetic membranes for desalination, in: C.H Nielsen (Ed.) Biomimetic membranes for sensor and separation applications, Springer, 2012 108 [42 ] D Kozono, M Yasui, L.S