Amphiphilic polyelectrolyte complexes, multilayers and blends

Abstract

Disclosed is a composite membrane comprising a porous support and a selective layer comprising a first copolymer and a second copolymer, the first copolymer comprising a first plurality of hydrophobic repeat units and a plurality of cationic repeat units, and the second copolymer comprising a second plurality of hydrophobic repeat units and a plurality of anionic repeat units. Methods of making and using such composite membranes are also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 325,274, filed March 30, 2022, the contents of which are incorporated herein by reference in their entirety. GOVERNMENT SUPPORT

[0002] This invention was made with government support under Grant No. DEFE003185 awarded by the Department of Energy and Grant No. 1553661 awarded by the National Science Foundation. The United States Government has certain rights in this invention. [Background technology]

[0003] One of the most energy-consuming activities in the chemical industry is the separation of chemical compounds. Membranes are excellent candidates to achieve efficient separation: they are scalable, energy-efficient and already widely used in gas and liquid separation processes. Nevertheless, the separation capacity, fouling and stability of membranes prepared by traditional methods limit their widespread use.

[0004] Currently, separation of molecules of similar size is performed by using energy-intensive methods such as chromatography, distillation, and extraction. For example, the purification of propane and ethene alone accounts for 0.3% of global energy consumption. Utilizing membranes for these challenging separations instead of current methods would increase the sustainability of these processes while significantly reducing energy consumption. Other separations, such as the separation of benzene derivatives from each other and the isolation of value-added bioactive compounds, are also potential processes that could use membranes.

[0005] In addition to limitations regarding selectivity, membrane fouling severely limits the wider use of membranes in applications where the feed has high concentrations of components (e.g., biopolymers, particulates, and / or oils). Therefore, it is important to consider fouling prevention when designing novel membrane materials. Fouling is one of the most relevant research areas in membrane filtration and a major obstacle to improving the performance of membrane separation processes. 6 Fouling has a detrimental effect on membrane performance and integrity. Given the limitations of commercially available membranes against foulants, the ability to tailor membrane properties such as permeance, pore size, and selectivity while maintaining ease of manufacture and high fouling resistance has the potential to transform the water filtration field.

[0006] Finally, membranes with higher selectivity can improve the economic feasibility of membrane processes for many applications. For example, membranes with tunable pore size and charge on the nanometer scale could be useful in bioseparation, treatment of complex wastewater, selective removal of organics (e.g., dyes) and other contaminants from solutions for reuse, water softening, pretreatment of seawater for desalination by reverse osmosis (RO), and final treatment of secondary and tertiary wastewater effluents. In all these cases, it is essential to combine selectivity with fouling resistance.

[0007] Previous studies have demonstrated that random zwitterionic amphiphilic copolymer (r-ZAC) membranes can be formed via the self-assembly of zwitterionic nanodomains that act as a network of effective nanochannels for water permeation. The main features of r-ZAC membranes include excellent fouling resistance, a size cutoff of approximately 1-1.5 nm, and low salt ion retention. However, although a variety of zwitterionic monomers can be synthesized, only a handful are commercially available, and some are only available from one supplier. Furthermore, most zwitterionic monomers have low solubility in many solvents, further adding to the difficulty of their synthesis. As a result, the range of r-ZAC chemicals that can be feasibly converted into membranes that are manufactured on a large scale is limited. On the other hand, ionic or ionizable monomers are widely available, inexpensive, and usually easy to solubilize and synthesize.

[0008] Another type of selective layer that has gained attention in the past decade is polyelectrolyte multilayers, which are constructed by layer-by-layer (LBL) deposition of oppositely charged polyelectrolytes. The multilayer approach allows the development of membranes based on the formation of polyelectrolyte complexes between multiple oppositely charged water-soluble homopolymers. Although these membranes have shown excellent membrane performance, especially in the removal of trace fouling substances, there is no meaningful study of their uncrosslinked long-term stability. In addition, their fabrication methods require multiple steps and would be complicated to scale up. These coatings are typically produced by multiple rounds of dip or spray coating of alternating anionic and cationic water-soluble polyelectrolytes with intervening rinses. Typically, at least 3-5 bilayers (hence 12-20 dip or spray steps) are required. Summary of the Invention [Means for solving the problem]

[0009] In one aspect, the present disclosure provides a composite membrane comprising a porous support and a selective layer comprising a first copolymer and a second copolymer, The first copolymer comprises a first plurality of hydrophobic repeat units and a plurality of cationic repeat units; the second copolymer comprises a second plurality of hydrophobic repeat units and a plurality of anionic repeat units; The first copolymer and the second copolymer provide a composite membrane that is essentially insoluble in water (eg, under operating conditions).

[0010] In another aspect, the present disclosure provides a method for separating a solute from a solution comprising contacting the solution with a composite membrane disclosed herein.

[0011] In another aspect, the present disclosure provides a method of producing a composite membrane as disclosed herein, comprising applying a first copolymer as disclosed herein and a second copolymer as disclosed herein to a porous support, thereby producing a composite membrane as disclosed herein. [Brief description of the drawings]

[0012] [Figure 1] NMR spectrum of the chemical structure of A+ showing copolymerization of two monomer units. [Diagram 2] NMR spectrum of the S-chemical structure showing copolymerization of two monomer units. [Diagram 3] 1 shows an SEM image of SA coated on PS35. [Figure 4] The percent rejection of the neutral dye by all membranes is shown. [Diagram 5] An S-curve using a neutral solute is shown. [Figure 6] The rejection rates of different concentrations of Na2SO4 are shown. [Figure 7] The rejection rates of different concentrations of Na2SO4 are shown. [Figure 8] The rejection rates of different concentrations of Na2SO4 are shown. [Figure 9] The inhibition rates of different concentrations of MgCl2 are shown. [Figure 10] The inhibition rates of different concentrations of MgCl2 are shown. [Figure 11] The inhibition rates of different concentrations of MgCl2 are shown. [Figure 12] The inhibition rates of different concentrations of NaCl are shown. [Figure 13] The inhibition rates of different concentrations of NaCl are shown. [Figure 14] The inhibition rates of different concentrations of NaCl are shown. [Figure 15] The oil-in-water fouling tests of S- and SA for 5 h are shown. The initial permeation flux of these membranes was set at 10 L / m2.h. [Figure 16] NMR spectrum of the chemical structure of M-, showing copolymerization of two monomer units. [Figure 17] Shows an SEM image of AM coated on PS35. [Figure 18] Shows an SEM image of 70 / 30 coated on PS35. [Figure 19] 1 shows the water permeance of different APEC blend layers. [Figure 20] 4 shows the inhibition of vitamin B12 using different APEC blend layers. [Figure 21] The rejection rates of different concentrations of Na2SO4 are shown. [Figure 22] The inhibition rates of different concentrations of MgCl2 are shown. [Diagram 23] The inhibition rates of different concentrations of NaCl are shown. [Figure 24] NMR spectrum of the chemical structure of A2+ showing copolymerization of two monomer units. [Diagram 25] NMR spectrum of the S-chemical structure showing copolymerization of two monomer units. [Figure 26] 1 shows an SEM image of A2S coated on PS35. [Figure 27] The percent rejection of neutral dye by A2S, AS, and control membranes is shown. [Figure 28] An S-curve using a neutral solute is shown. [Figure 29] The rejection rates of different concentrations of Na2SO4 are shown. [Diagram 30] The inhibition rates of different concentrations of MgCl2 are shown. [Diagram 31] The inhibition rates of different concentrations of NaCl are shown. [Diagram 32] NMR spectrum of the chemical structure of A+ showing copolymerization of two monomer units. [Diagram 33] NMR spectrum of the chemical structure of S2- indicating copolymerization of two monomer units. [Diagram 34] 1 shows an SEM image of AS2 coated on PS35. [Diagram 35] The percent rejection of neutral dye by AS2, AS, and control membranes is shown. [Diagram 36] The rejection rates of different concentrations of Na2SO4 are shown. [Figure 37] The inhibition rates of different concentrations of MgCl2 are shown. [Figure 38] The inhibition rates of different concentrations of NaCl are shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Disclosed is a thin film composite (TFC) membrane having a thin "selective layer" coated on a porous support, the selective support comprising a combination of at least two of the following copolymers: 1) "cationic copolymers" that contain at least two types of repeat units: hydrophobic repeat units, the homopolymers of which are insoluble in water, and cationic repeat units, which are at least partially positively charged in water; 2) "Anionic copolymers" which contain at least two types of repeat units: hydrophobic repeat units as described above, and anionic repeat units which are at least partially negatively charged in water.

[0014] In certain preferred embodiments, both of the copolymers are essentially insoluble in water under the conditions of use. Typically, each copolymer contains about 5-80% by weight of charged (anionic or cationic) repeat units, more preferably 15-75% charged repeat units, more preferably 30-60% charged repeat units. This feature differentiates this technology from, for example, polyelectrolyte multilayer coatings that contain water-soluble polyelectrolytes that do not contain hydrophobic repeat units that are deposited from aqueous solutions.

[0015] In certain preferred embodiments, both copolymers may have an average molar mass of at least 30,000 g / mol, more preferably greater than 50,000 g / mol, even more preferably greater than 100,000 g / mol.

[0016] The two copolymers can be deposited onto a porous support to form a selective layer, for example, by one of two methods: i) Each copolymer is coated sequentially (or sequentially) onto the support, producing at least one layer of anionic copolymer and one layer of cationic copolymer on the support. This family of membranes is hereafter called "bilayer membranes", although in principle a greater number of layers is possible. ii) making a mixture or blend of the two copolymers by dissolving both in the same solvent and then coating this blend onto a support to make the selective layer. This family of membranes is called "blend membranes".

[0017] In either case, the effective pore size of the support membrane is significantly larger than the effective pore size of the TFC membrane; the selective layer significantly alters the rejection properties of the support.

[0018] Exemplary hydrophobic repeat units include repeat units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA); other fluorinated acrylates, methacrylates and acrylamides (e.g., pentafluoropropyl methacrylate, heptafluorobutyl methacrylate, pentafluorophenyl methacrylate); styrene; methyl methacrylate (or methyl methacrylate); acrylonitrile; 2-chloroethyl methacrylate; 2-bromoethyl methacrylate; allyl methacrylate (or allyl methacrylate); and other monomers that fit the above criteria. Additionally, hydrophobic monomeric peptides or blocked amino acids that do not have ionizable / charged groups under the conditions of use can also be used as hydrophobic monomeric units.

[0019] Exemplary anionic repeat units include methacrylic acid (MAA); 2-sulfoethyl methacrylate (SEMA); L-tryptophan-methacrylamide; D-tryptophan-methacrylamide; L or D-tryptophan-acrylamide; L or D-alanine-methacrylamide; L or D-alanine-acrylamide; L or D-valine-methacrylamide; L or D-valine-acrylamide; L or D-isoleucine-methacrylamide; L or D-isoleucine-acrylamide; L or D-allo-isoleucine-acrylamide; L-methacrylamide;L- or D-allo-isoleucine-acrylamide;L- or D-methionine-methacrylamide;L- or D-methionine-acrylamide;L- or D-phenylalanine-methacrylamide;L- or D-phenylalanine-acrylamide;L- or D-tyrosine-methacrylamide;L- or D-tyrosine-acrylamide;L- or D-histidine-methacrylamide;L- or D-histidine-acrylamide;L- or D-glutamic acid-methacrylamide;L- or D-glutamic acid-acrylamide; L or D-Aspartic acid-acrylamide;L or D-Aspartic acid-methacrylamide;Acrylic acid;2-Carboxyethyl acrylate;Mono-2-(methacryloyloxy)ethyl succinate;Mono[2-(methacryloyloxy)ethyl]maleate;Sodium 4-vinylbenzenesulfonate;2-Acrylamido-2-methylpropanesulfonic acid;2-Acrylamido-2-methyl-1-propanesulfonic acid sodium salt;2-Acrylamido-2-methyl-1-propanesulfonic acid;3-Sulfopropyl acrylate potassium salt ammonium salts;3-sulfopropyl methacrylate potassium salts;3-vinylbenzoic acid;4-vinylbenzoic acid;2-vinylbenzoic acid;4-(2-propenyl)benzoic acid;2-methyl-2-propene-1-sulfonic acid sodium salt;vinylsulfonic acid sodium salt;vinylphosphonic acid;(4-ethenylphenyl)methylphosphonic acid;methacrylate, acrylate, methacrylamide, acrylamide, styrene, or vinyl derivatives containing carboxylic acids, sulfonates, phosphates or other ionizable / charged groups which become negatively charged under the conditions of use;Also, monomeric peptides having ionizable / charged groups that are negatively charged under the conditions of use may be used as anionic monomeric units.

[0020] Exemplary cationic repeat units include, but are not limited to, [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MAETA); [3(methacryloylamino)propyl]trimethylammonium chloride; [2-(acryloyloxy)ethyl]trimethylammonium chloride; (3-acrylamidopropyl)trimethylammonium chloride; 4-vinylbenzyl(triphenyl)phosphonium chloride; (vinylbenzyl)trimethylammonium chloride methacrylate; 3-vinylaniline; 4-vinylaniline; 2-isopropenylaniline; N-(3-amino Repeat units derived from N-propyl methacrylamide hydrochloride; N-vinylimidazolium salts; l-allyl-3-vinylimidazolium salts; l-allyl-2-methyl-5-vinyl-pyridinium salts; l-allyl-5-vinyl-pyridinium salts; 1-methyl-l-(l-vinylcyclohexyl)pyrrolidinium iodide; methacrylate, acrylate, methacrylamide, acrylamide, styrene, or vinyl derivatives containing amine, pyridinium, imidazolium, phosphonium, pyrrolidinium, or other ionizable / charged groups that have a positive charge under the conditions of use. Repeat units with a strong cationic charge (e.g., quaternary amine groups) are preferred. In addition, monomeric peptides with ionizable / charged groups that have a positive charge under the conditions of use can also be used as cationic monomeric units.

[0021] In certain embodiments, the membranes described herein include the following features: i) Effective pore size smaller than the support ii) Scalable manufacturing.

[0022] In certain embodiments, the membranes disclosed herein, such as bilayer membranes, include the following features: They exhibit smaller effective pore sizes than membranes prepared by coating either the anionic or cationic copolymer alone onto the same support, as quantified by measuring the rejection of neutral solutes. Their water permeance is within the range of commercially available membranes of comparable effective pore size and can potentially be tuned to higher values. Copolymers containing essentially any pair of ionizable or charged groups (i.e., anionic and cationic) can be used to prepare membranes as long as they are soluble and coatable. This differs from blend membranes in which certain paired functional groups have very limited solubility and will solidify when mixed in solution, limiting the options available. Without wishing to be bound by theory, the selectivity of these membranes is believed to arise from a very thin layer at the interface of the two coated layers, where the anionic and cationic copolymers interact to form a tighter "mesh" than either copolymer would have alone. The selectivity / effective pore size of these membranes can be controlled by the hydrophobic monomer / charged monomer ratio of each copolymer. Additionally, the degree of interlayer mixing, influenced by factors such as solvent selection, temperature, casting speed, external air flow, and post-treatment, can affect the effective pore size, as well as the chemical nature of the charged group pairs. These membranes exhibit improved anti-fouling properties, e.g., the fully mixed (i.e., nearly homogeneous throughout) or nearly fully mixed and nearly neutrally charged layers are particularly anti-fouling, mimicking previously reported polyampholyte electrolyte membranes.

[0023] Furthermore, it is anticipated that bilayers can be designed to be crosslinkable, including at the interface (e.g., via reactions between anionic and cationic copolymers), providing further stability and tunability. These reactions include, for example, reactions between epoxides and primary amines or alcohols; alkyl halides and tertiary amines; azides and alkynes. This requires either the presence of a third monomer unit in the polymer; and / or the presence of reactive groups on the charged and / or hydrophobic monomer units.

[0024] In certain embodiments, the membranes disclosed herein, such as blend membranes, include the following features: Blend membranes have smaller effective pore sizes than the support and usually the individual copolymers, as quantified by measuring the rejection of neutral solutes. However, their effective pore sizes are typically larger than membranes prepared using the bilayer approach with the same copolymers. They exhibit a highly tunable effective pore size, which can be controlled by varying the molar ratio of anionic and cationic groups. This parameter can also control / modify the permeance and salt rejection (or salt rejection). -High fouling resistance compared to other membranes on the market, especially membranes with neutral or near-neutral charge.

[0025] In certain embodiments, the membranes disclosed herein (e.g., bilayer and blend membranes) include the following features: · Facile and scalable synthesis of copolymers. Easy and scalable fabrication of membranes with a wide and controlled range of selectivity that can be tailored for the desired performance (e.g., water treatment for desalination, water softening, size-based separation of organic molecules, selective removal of pollutants). -Fouling resistance against a variety of fouling substances. -Chlorine resistant. Chemical resistance.

[0026] In certain embodiments, methods for producing material systems and membranes with improved capabilities are described. Past multilayer membranes incorporating charged groups have focused exclusively on water-soluble polyelectrolyte multilayers deposited by adsorption from water; the present invention describes rod coating of water-insoluble copolymers from organic solutions. Membrane performance is highly tunable and adaptable.

[0027] The membranes disclosed herein behave differently than polyelectrolyte multilayers: the formation of a tightly interwoven / composite layer at the interface of two separately deposited layers has not been reported in any other system.

[0028] The disclosed invention can be used in many filtration processes where size-selective and charge-selective separations are required, including water and wastewater treatment, and nutrient separation and recovery.

[0029] In one aspect, the present disclosure provides a composite membrane comprising a porous support and a selective layer comprising a first copolymer and a second copolymer, The first copolymer comprises a first plurality of hydrophobic repeat units and a plurality of cationic repeat units; the second copolymer comprises a second plurality of hydrophobic repeat units and a plurality of anionic repeat units; The first copolymer and the second copolymer provide a composite membrane that is essentially insoluble in water (eg, under operating conditions).

[0030] In certain preferred embodiments, the first copolymer and the second copolymer are insoluble in water (eg, under operating conditions).

[0031] In some embodiments, the composite membrane is a thin film composite membrane.

[0032] In one embodiment, the composite membrane has a thickness of about 20 μm to about 1,000 μm, In one embodiment, the composite membrane has a thickness of about 50 μm to about 200 μm.

[0033] In some embodiments, the selective layer has a thickness of about 30 nm to about 5 μm. In some embodiments, the selective layer has a thickness of about 30 nm to about 1,000 nm. In some embodiments, the selective layer has a thickness of about 10 nm, about 25 nm, about 50 nm, about 75 nm, about 100 nm, about 125 nm, about 150 nm, about 175 nm, about 200 nm, about 225 nm, about 250 nm, about 275 nm, about 300 nm, about 325 nm, about 350 nm, about 375 nm, about 400 nm, about 425 nm, about 450 nm, about 475 nm, about 500 nm, about 525 nm, about 550 nm, about 575 nm, or about 600 nm. In certain embodiments, the selective layer has a thickness of about 400 nm, about 425 nm, about 450 nm, about 475 nm, about 500 nm, about 525 nm, about 550 nm, about 575 nm, or about 600 nm.

[0034] In certain embodiments, the cationic repeat units are partially positively charged in water (e.g., in water at neutral pH or under operating conditions). In certain embodiments, the cationic repeat units are positively charged in water (e.g., in water at neutral pH or under operating conditions).

[0035] In certain embodiments, the anionic repeat units are partially negatively charged in water (e.g., in water at neutral pH or under operating conditions). In certain embodiments, the anionic repeat units are negatively charged in water (e.g., in water at neutral pH or under operating conditions).

[0036] In certain embodiments, the selective layer consists essentially of the first copolymer and the second copolymer.

[0037] In certain embodiments, the first copolymer comprises about 5-80% by weight of the cationic repeat units. In certain embodiments, the first copolymer comprises about 15-75% by weight of the cationic repeat units. In certain embodiments, the first copolymer comprises about 30-60% by weight of the cationic repeat units. In certain embodiments, the first copolymer comprises about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, or about 80% by weight of the cationic repeat units. In certain embodiments, the first copolymer comprises about 5-80 mol% of the cationic repeat units. In certain embodiments, the first copolymer comprises about 15-75 mol% of the cationic repeat units.

[0038] In certain embodiments, the first copolymer comprises about 5-80 mol% (mol %) of the cationic repeat units. In certain embodiments, the first copolymer comprises about 15-75 mol% of the cationic repeat units. In certain embodiments, the first copolymer comprises about 30-60 mol% of the cationic repeat units. In certain embodiments, the first copolymer comprises about 10 mol%, about 20 mol%, about 30 mol%, about 40 mol%, about 50 mol%, about 60 mol%, about 70 mol%, or about 80 mol% of the cationic repeat units. In certain embodiments, the first copolymer comprises about 5-80 mol% of the cationic repeat units. In certain embodiments, the first copolymer comprises about 15-75 mol% of the cationic repeat units.

[0039] In certain embodiments, the first copolymer comprises about 5-80% by weight of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 15-75% by weight of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 30-60% by weight of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 10% by weight, about 20% by weight, about 30% by weight, about 40% by weight, about 50% by weight, about 60% by weight, about 70% by weight, or about 80% by weight of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 5-80% by weight of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 15-75% by weight of the first plurality of hydrophobic repeating units.

[0040] In certain embodiments, the first copolymer comprises about 5-80 mol% of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 15-75 mol% of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 30-60 mol% of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 10 mol%, about 20 mol%, about 30 mol%, about 40 mol%, about 50 mol%, about 60 mol%, about 70 mol%, or about 80 mol% of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 5-80 mol% of the first plurality of hydrophobic repeating units. In certain embodiments, the first copolymer comprises about 15-75 mol% of the first plurality of hydrophobic repeating units.

[0041] In certain embodiments, the second copolymer comprises about 5-80% by weight of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 15-75% by weight of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 30-60% by weight of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 10% by weight, about 20% by weight, about 30% by weight, about 40% by weight, about 50% by weight, about 60% by weight, about 70% by weight, or about 80% by weight of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 5-80 mol% of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 15-75 mol% of the plurality of anionic repeat units.

[0042] In certain embodiments, the second copolymer comprises about 5-80 mol% of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 15-75 mol% of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 30-60 mol% of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 10 mol%, about 20 mol%, about 30 mol%, about 40 mol%, about 50 mol%, about 60 mol%, about 70 mol%, or about 80 mol% of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 5-80 mol% of the plurality of anionic repeat units. In certain embodiments, the second copolymer comprises about 15-75 mol% of the plurality of anionic repeat units.

[0043] In certain embodiments, the second copolymer comprises about 5-80% by weight of the second plurality of hydrophobic repeating units. In certain embodiments, the second copolymer comprises about 15-75% by weight of the second plurality of hydrophobic repeating units. In certain embodiments, the second copolymer comprises about 30-60% by weight of the second plurality of hydrophobic repeating units. In certain embodiments, the second copolymer comprises about 10% by weight, about 20% by weight, about 30% by weight, about 40% by weight, about 50% by weight, about 60% by weight, about 70% by weight, or about 80% by weight of the second plurality of hydrophobic repeating units. In certain embodiments, the second copolymer comprises about 5-80% by weight of the second plurality of hydrophobic repeating units. In certain embodiments, the second copolymer comprises about 15-75% by weight of the second plurality of hydrophobic repeating units.

[0044] In certain embodiments, the second copolymer comprises about 5-80 mol% of the second plurality of hydrophobic repeat units. In certain embodiments, the second copolymer comprises about 15-75 mol% of the second plurality of hydrophobic repeat units. In certain embodiments, the second copolymer comprises about 30-60 mol% of the second plurality of hydrophobic repeat units. In certain embodiments, the second copolymer comprises about 10 mol%, about 20 mol%, about 30 mol%, about 40 mol%, about 50 mol%, about 60 mol%, about 70 mol%, or about 80 mol% of the second plurality of hydrophobic repeat units. In certain embodiments, the second copolymer comprises about 5-80 mol% of the second plurality of hydrophobic repeat units. In certain embodiments, the second copolymer comprises about 15-75 mol% of the second plurality of hydrophobic repeat units.

[0045] In certain embodiments, the first copolymer has an average molar mass of at least 50,000 g / mol. In certain embodiments, the first copolymer has an average molar mass of at least 100,000 g / mol. In certain embodiments, the first copolymer has an average molar mass of 20,000 g / mol to about 500,000 g / mol. In certain embodiments, the first copolymer has an average molar mass of 30,000 g / mol to about 500,000 g / mol. In certain embodiments, the first copolymer has an average molar mass of 50,000 g / mol to about 500,000 g / mol. In certain embodiments, the first copolymer has an average molar mass of 100,000 g / mol to about 500,000 g / mol.

[0046] In certain embodiments, the second copolymer has an average molar mass of at least 50,000 g / mol. In certain embodiments, the second copolymer has an average molar mass of at least 100,000 g / mol. In certain embodiments, the second copolymer has an average molar mass of 20,000 g / mol to about 500,000 g / mol. In certain embodiments, the second copolymer has an average molar mass of 30,000 g / mol to about 500,000 g / mol. In certain embodiments, the second copolymer has an average molar mass of 50,000 g / mol to about 500,000 g / mol. In certain embodiments, the second copolymer has an average molar mass of 100,000 g / mol to about 500,000 g / mol.

[0047] In certain embodiments, the first copolymer and the second copolymer are layered sequentially on the porous support (e.g., the first copolymer and the second copolymer are applied sequentially to the porous support layer). In certain embodiments, the first copolymer is the first layer (e.g., the outermost layer) and the second copolymer is the second layer (e.g., the first copolymer layer is on the second copolymer layer, and the second copolymer layer is in contact with the porous support). In other embodiments, the second copolymer is the first layer (e.g., the outermost layer) and the first copolymer is the second layer (e.g., the second copolymer layer is on the first copolymer layer, and the first copolymer layer is in contact with the porous support). In other embodiments, the first copolymer and the second copolymer are intermingled on the porous support (e.g., the first copolymer and the second copolymer form a homogenous layer on the porous support).

[0048] In certain embodiments, the first plurality of hydrophobic repeat units comprises repeat units derived from acrylates (e.g., alkyl acrylates, fluorinated acrylates or methacrylates), acrylamides (e.g., fluorinated acrylamides), styrene, or hydrophobic amino acids. In certain embodiments, the first plurality of hydrophobic repeat units comprises repeat units derived from methacrylates. In certain embodiments, the first plurality of hydrophobic repeat units comprises repeat units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA), pentafluoropropyl methacrylate, heptafluorobutyl, pentafluorophenyl methacrylate, styrene, methyl methacrylate, acrylonitrile, 2-chloroethyl methacrylate, 2-bromoethyl methacrylate, and allyl methacrylate. In certain preferred embodiments, the first plurality of hydrophobic repeat units comprises repeat units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA).

[0049] In certain embodiments, the second plurality of hydrophobic repeat units comprises repeat units derived from acrylates (e.g., alkyl acrylates, fluorinated acrylates or methacrylates), acrylamides (e.g., fluorinated acrylamides), styrene, or hydrophobic amino acids. In certain embodiments, the second plurality of hydrophobic repeat units comprises repeat units derived from methacrylates. In certain embodiments, the second plurality of hydrophobic repeat units comprises repeat units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA), pentafluoropropyl methacrylate, heptafluorobutyl, pentafluorophenyl methacrylate, styrene, methyl methacrylate, acrylonitrile, 2-chloroethyl methacrylate, 2-bromoethyl methacrylate, and allyl methacrylate. In certain preferred embodiments, the second plurality of hydrophobic repeat units comprises repeat units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA).

[0050] In certain embodiments, the plurality of cationic repeat units comprises repeat units derived from amine, pyridinium, imidazolium, phosphonium, or pyrrolidinium substituted acrylate, acrylamide, styrene, or vinyl monomers. In certain embodiments, the plurality of cationic repeat units comprises repeat units derived from [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MAETA), [3(methacryloylamino)propyl]trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, (3-acrylamidopropyl)trimethylammonium chloride; 4-vinylbenzyl(triphenyl)phosphonium chloride, (vinylbenzyl)trimethylammonium chloride methacrylate, 3-vinylaniline, 4-vinylaniline, 2-isopropenylaniline, N-(3-aminopropyl)methacrylamide hydrochloride, N-vinylimidazolium, 1-allyl-3-vinylimidazolium, l-allyl-2methyl-5-vinyl-pyridinium, l-allyl-5-vinyl-pyridinium, or 1-methyl-1-(1-vinylcyclohexyl)pyrrolidinium iodide. In certain preferred embodiments, the plurality of cationic repeat units comprises repeat units derived from 2-(methacryloyloxy)ethyl]trimethylammonium chloride.

[0051] In certain embodiments, the plurality of anionic repeat units comprises repeat units derived from acrylate, acrylamide, styrene, or vinyl monomers substituted with carboxylic acid, sulfonate, or phosphate, hi certain embodiments, the plurality of anionic repeat units comprises repeat units derived from methacrylate.In certain embodiments, the plurality of anionic repeat units are selected from the group consisting of methacrylic acid (MAA), 2-sulfoethyl methacrylate (SEMA), L-tryptophan-methacrylamide, D-tryptophan-methacrylamide, L or D-tryptophan-acrylamide, L or D-alanine-methacrylamide, L or D-alanine-acrylamide, L or D-valine-methacrylamide, L or D-valine-acrylamide, L or D-isoleucine-meth ... Leucine-acrylamide, L or D-allo-isoleucine-methacrylamide, L or D-allo-isoleucine-acrylamide, L or D-methionine-methacrylamide, L or D-methionine-acrylamide, L or D-phenylalanine-methacrylamide, L or D-phenylalanine-acrylamide, L or D-tyrosine-methacrylamide, L or D-tyrosine-acrylamide, L or D-histidine-methacrylamide, L or D-histidine-acrylamide Amides, L or D-glutamic acid-methacrylamide, L or D-glutamic acid-acrylamide, L or D-aspartic acid-acrylamide, L or D-aspartic acid-methacrylamide, acrylic acid, 2-carboxyethyl acrylate, mono-2-(methacryloyloxy)ethyl succinate, mono-2-(methacryloyloxy)ethyl maleate, sodium 4-vinylbenzenesulfonate, 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, In certain embodiments, the plurality of anionic repeat units comprises repeat units derived from 2-sulfoethyl methacrylate.In other embodiments, the plurality of anionic repeat units comprises repeat units derived from methacrylic acid.

[0052] In certain embodiments, the first copolymer is a block copolymer. In certain embodiments, the first copolymer is a statistical (e.g., substantially random) copolymer. In certain preferred embodiments, the first copolymer is a random copolymer. In certain embodiments, the second copolymer is a graft copolymer or a comb-shaped copolymer.

[0053] In certain embodiments, the second copolymer is a block copolymer. In certain embodiments, the first copolymer is a statistical (e.g., substantially random) copolymer. In certain preferred embodiments, the second copolymer is a random copolymer. In certain preferred embodiments, the second copolymer is a graft copolymer or a comb copolymer.

[0054] In certain embodiments, the effective pore size of the composite membrane is smaller than the effective pore size of a membrane prepared by coating only the first copolymer or only the second copolymer onto the same porous support, in certain embodiments, the effective pore size is quantified by measuring the rejection of neutral (e.g., uncharged) solutes.

[0055] In certain embodiments, the first copolymer is crosslinked.

[0056] In certain embodiments, the second copolymer is crosslinked.

[0057] In another aspect, the disclosure provides a method for separating a solute from a solution, comprising contacting the solution with a composite membrane. In certain embodiments, the solution is passed (e.g., filtered) through the composite membrane. In certain embodiments, the solute is a salt (e.g., sodium chloride). In certain embodiments, the solution is seawater.

[0058] In another aspect, the present disclosure provides a method of making a composite membrane as disclosed herein, comprising applying a first copolymer as disclosed herein and a second copolymer as disclosed herein to a porous support, thereby producing a composite membrane as disclosed herein.

[0059] In some embodiments, the first copolymer and the second copolymer are applied sequentially to the porous support layer, thereby forming a bilayer membrane. In certain embodiments, the first copolymer is applied first and the second copolymer is applied second. In certain embodiments, the first copolymer is applied second and the second copolymer is applied first. In other embodiments, the first copolymer and the second copolymer are applied to the porous support layer as a blend (e.g., the first copolymer and the second copolymer are mixed before application), thereby forming a blend membrane.

[0060] In certain embodiments, the first copolymer is dissolved in a protic solvent (e.g., methanol) before coating. In certain embodiments, the second copolymer is dissolved in a protic solvent (e.g., methanol) before coating. In certain embodiments, the first copolymer and the second copolymer are each dissolved in a protic solvent (e.g., methanol) before coating.

[0061] definition Unless otherwise defined herein, scientific and technical terms used in this application have the meanings that are commonly understood by those of ordinary skill in the art.

[0062] The methods and techniques of the present disclosure are generally carried out according to conventional methods that are well known in the art and described in various general and more specific references cited and discussed throughout this specification, unless otherwise indicated.

[0063] Chemical terms used herein, unless otherwise defined herein, are used according to conventional usage in the art as exemplified by "The McGraw-Hill Dictionary of Chemical Terms", Parker S., Ed., McGraw-Hill, San Francisco, CA (1985).

[0064] All of these and any other publications, patents and published patent applications mentioned in this application are specifically incorporated herein by reference. In case of conflict, the present specification, including specific definitions, will control.

[0065] As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes both cases where the event or circumstance occurs and cases where the event or circumstance does not occur. For example, "optionally substituted alkyl" refers both to cases where the alkyl is substituted and to cases where the alkyl is not substituted.

[0066] It is understood that the substituents and substitution patterns of the compounds of the present invention can be selected by one skilled in the art to result in chemically stable compounds that can be readily synthesized from readily available starting materials by techniques known in the art as well as the methods described below. When a substituent is itself substituted with multiple groups, it is understood that these multiple groups can be on the same carbon or on different carbons as long as a stable structure is obtained.

[0067] As used herein, the term "optionally substituted" refers to the replacement of one to six hydrogen radicals in a given structure with the radical of a specified substituent, including, but not limited to, hydroxyl, hydroxyalkyl, alkoxy, halogen, alkyl, nitro, silyl, acyl, acyloxy, aryl, cycloalkyl, heterocyclyl, amino, aminoalkyl, cyano, haloalkyl, haloalkoxy, -OCO-CH2-O-alkyl, -OP(O)(O-alkyl)2, or CH2-OP(O)(O-alkyl). Preferably, "optionally substituted" refers to the replacement of one to four hydrogen radicals in a given structure with the above substituents. More preferably, one to three hydrogen radicals are replaced by the above substituents. It is understood that the substituents may be further substituted.

[0068] As used herein, the term "alkyl" refers to any alkyl group having a C1-C 10 Straight chain alkyl group or C1-C 10 It refers to saturated aliphatic groups including but not limited to branched alkyl groups. Preferably, the "alkyl" group refers to a C1-C6 straight chain alkyl group or a C1-C6 branched chain alkyl group. Most preferably, the "alkyl" group refers to a C1-C4 straight chain alkyl group or a C1-C4 branched chain alkyl group. Examples of "alkyl" include, but are not limited to, methyl, ethyl, 1-propyl, 2-propyl, n-butyl, sec-butyl, tert-butyl, 1-pentyl, 2-pentyl, 3-pentyl, neo-pentyl, 1-hexyl, 2-hexyl, 3-hexyl, 1-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, 1-octyl, 2-octyl, 3-octyl, or 4-octyl. The "alkyl" group may be substituted.

[0069] The term "acyl" is art-recognized and refers to a group represented by the general formula hydrocarbylC(O)-, preferably alkylC(O)-.

[0070] The term "acylamino" is art-recognized and refers to an amino group substituted with an acyl group and may be represented, for example, by the formula hydrocarbylC(O)NH-.

[0071] The term "acyloxy" is art-recognized and refers to a group represented by the general formula hydrocarbylC(O)O-, preferably alkylC(O)O-.

[0072] The term "alkoxy" refers to an alkyl group having an oxygen attached thereto. Representative alkoxy groups include methoxy, ethoxy, propoxy, tert-butoxy, and the like.

[0073] The term "alkoxyalkyl" refers to an alkyl group substituted with an alkoxy group and can be represented by the general formula alkyl-O-alkyl.

[0074] The term "alkyl" refers to saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl-substituted cycloalkyl groups, and cycloalkyl-substituted alkyl groups. In preferred embodiments, a straight-chain or branched-chain alkyl group has 30 or fewer carbon atoms in its backbone (e.g., C for straight chain). 1-30 , C for branched chains 3-30 ), more preferably having 20 or fewer carbon atoms.

[0075] Furthermore, the term "alkyl," as used throughout the specification, examples, and claims, is intended to include both unsubstituted and substituted alkyl groups, the latter of which refers to alkyl moieties having substituents replacing a hydrogen on one or more carbons of the hydrocarbon backbone, and includes haloalkyl groups such as trifluoromethyl and 2,2,2-trifluoroethyl.

[0076] "C x-y " or "C x ~C yThe term " when used with chemical moieties such as acyl, acyloxy, alkyl, alkenyl, alkynyl, or alkoxy, is meant to include groups containing x to y carbons in the chain. CO alkyl indicates a hydrogen if the group is in a terminal position, or a bond if it is internal. For example, C 1-6 Alkyl groups contain 1 to 6 carbon atoms in the chain.

[0077] The term "alkylamino," as used herein, refers to an amino group substituted with at least one alkyl group.

[0078] The term "alkylthio," as used herein, refers to a thiol group substituted with an alkyl group and can be represented by the general formula alkylS-.

[0079] The term "amide," as used herein, refers to the following group: [ka] [In the formula, R 9 and R 10 each independently represents hydrogen or a hydrocarbyl group, or R 9 and R 10 together with the N atom to which they are attached complete a heterocycle having 4 to 8 atoms in the ring structure.

[0080] The terms "amine" and "amino" are art-recognized and refer to both unsubstituted and substituted amines, and salts thereof, e.g., [ka] [In the formula, R 9 , R 10 , and R 10 ' each independently represent a hydrogen or a hydrocarbyl group, or R 9 and R 10 together with the N atom to which they are attached complete a heterocycle having 4-8 atoms in the ring structure. It refers to a part that can be expressed by

[0081] The term "aminoalkyl," as used herein, refers to an alkyl group substituted with an amino group.

[0082] The term "aralkyl," as used herein, refers to an alkyl group substituted with an aryl group.

[0083] The term "aryl" as used herein includes substituted or unsubstituted monocyclic aromatic groups in which each atom of the ring is carbon. Preferably, the ring is 5-7 membered, more preferably 6 membered. The term "aryl" also includes polycyclic ring systems having two or more cyclic rings, where two or more carbons are common to two adjacent rings, and at least one of the rings is aromatic, for example, the other cyclic rings can be cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl and / or heterocyclyl. Aryl groups include benzene, naphthalene, phenanthrene, phenol, aniline, and the like.

[0084] The term "carbamate" is art-recognized and refers to the following group: [ka] [In the formula, R 9 and R 10 each independently represents hydrogen or a hydrocarbyl group.

[0085] The term "carbocyclylalkyl," as used herein, refers to an alkyl group substituted with a carbocycle group.

[0086] The term "carbocycle" includes 5-7 membered monocyclic rings and 8-12 membered bicyclic rings. Each ring of a bicyclic carbocycle may be selected from saturated, unsaturated, and aromatic rings. Carbocycles include bicyclic molecules in which one, two, or more than two atoms are shared between the two rings. The term "fused carbocycle" refers to a bicyclic carbocycle in which each of the rings shares two adjacent atoms with the other ring. Each ring of a fused carbocycle may be selected from saturated, unsaturated, and aromatic rings. In an exemplary embodiment, an aromatic ring, such as phenyl, may be fused to a saturated or unsaturated ring, such as cyclohexane, cyclopentane, or cyclohexene. Any combination of saturated, unsaturated, and aromatic bicyclic rings is included in the definition of carbocycle, as valences permit. Exemplary "carbocycles" include cyclopentane, cyclohexane, bicyclo[2.2.1]heptane, 1,5-cyclooctadiene, 1,2,3,4-tetrahydronaphthalene, bicyclo[4.2.0]oct-3-ene, naphthalene, and adamantane. Exemplary fused carbocycles include decalin, naphthalene, 1,2,3,4-tetrahydronaphthalene, bicyclo[4.2.0]octane, 4,5,6,7-tetrahydro-1H-indene, and bicyclo[4.1.0]hept-3-ene. A "carbocycle" can be substituted at any one or more positions that can have a hydrogen atom.

[0087] The term "carbocyclylalkyl," as used herein, refers to an alkyl group substituted with a carbocycle group.

[0088] The term "carbonate" is art-recognized and refers to the group -OCO2-.

[0089] The term "carboxy," as used herein, refers to a group represented by the formula -CO2H.

[0090] The term "cycloalkyl" includes substituted or unsubstituted non-aromatic monocyclic structures, preferably 4-8 membered rings, more preferably 4-6 membered rings. The term "cycloalkyl" also includes polycyclic ring systems having two or more cyclic rings, where two or more carbons are common to two adjacent rings, and at least one of the rings is cycloalkyl and may include substituents (e.g., R 100 ) is attached to the cycloalkyl ring, for example, the other cyclic ring can be cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, and / or heterocyclyl. Heteroaryl groups include, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrazine, pyridazine, pyrimidine, denzodioxane, tetrahydroquinoline, and the like.

[0091] The term "ester" as used herein refers to the group -C(O)OR 9 Here, R 9 represents a hydrocarbyl group.

[0092] The term "ether" as used herein refers to a hydrocarbyl group bonded to another hydrocarbyl group via an oxygen. Thus, the ether substituent of a hydrocarbyl group can be hydrocarbyl-O-. Ethers can be symmetrical or asymmetrical. Examples of ethers include, but are not limited to, heterocycle-O-heterocycle and aryl-O-heterocycle. Ethers include "alkoxyalkyl" groups, which can be represented by the general formula alkyl-O-alkyl.

[0093] The terms "halo" and "halogen" as used herein mean halogen and include chloro, fluoro, bromo and iodo.

[0094] The terms "hetaralkyl" and "heteroaralkyl," as used herein, refer to an alkyl group substituted with a heteroaryl group.

[0095] The terms "heteroaryl" and "hetaryl" include substituted or unsubstituted aromatic monocyclic structures, preferably 5-7 membered rings, more preferably 5-6 membered rings, in which the ring structure contains at least one heteroatom, preferably 1-4 heteroatoms, more preferably 1 or 2 heteroatoms. The terms "heteroaryl" and "hetaryl" also include polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjacent rings, in which at least one of the rings is heteroaromatic, for example, the other cyclic rings may be cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, and / or heterocyclyl. Heteroaryl groups include, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrazine, pyridazine, and pyrimidine.

[0096] The term "heteroatom" as used herein means an atom of any element other than carbon or hydrogen. Preferred heteroatoms are nitrogen, oxygen and sulfur.

[0097] The term "heterocyclylalkyl," as used herein, refers to an alkyl group substituted with a heterocycle group.

[0098] The terms "heterocyclyl", "heterocycle" and "heterocyclic" refer to a substituted or unsubstituted non-aromatic ring structure, preferably a 3- to 10-membered ring, more preferably a 3- to 7-membered ring, in which the ring structure contains at least one heteroatom, preferably 1 to 4 heteroatoms, more preferably 1 or 2 heteroatoms. The terms "heterocyclyl" and "heterocyclic" also include polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjacent rings, in which at least one of the rings is heterocyclic, e.g., the other cyclic rings may be cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, and / or heterocyclyl. Heterocyclyl groups include, for example, piperidine, piperazine, pyrrolidine, morpholine, lactones, lactams, and the like.

[0099] The term "hydrocarbyl" as used herein refers to a group bonded through a carbon atom that does not have =O or =S substituents, typically has at least one carbon-hydrogen bond and a predominantly carbon backbone, but may optionally contain heteroatoms. Thus, groups such as methyl, ethoxyethyl, 2-pyridyl, and even trifluoromethyl are considered hydrocarbyl for purposes of this application, while substituents such as acetyl (having =O substituents on the linking carbon) and ethoxy (linked through oxygen rather than carbon) are not hydrocarbyl. Hydrocarbyl groups include, but are not limited to, aryl, heteroaryl, carbocyclic, heterocyclic, alkyl, alkenyl, alkynyl, and combinations thereof.

[0100] The term "hydroxyalkyl," as used herein, refers to an alkyl group substituted with a hydroxy group.

[0101] The term "lower", when used in conjunction with chemical moieties such as, for example, acyl, acyloxy, alkyl, alkenyl, alkynyl, or alkoxy, is meant to include groups in which there are 10 or fewer atoms, preferably 6 or fewer atoms, in the substituent. "Lower alkyl", for example, refers to alkyl groups containing 10 or fewer carbon atoms, preferably 6 or fewer carbon atoms. In certain embodiments, the acyl, acyloxy, alkyl, alkenyl, alkynyl, or alkoxy substituents defined herein are lower acyl, lower acyloxy, lower alkyl, lower alkenyl, lower alkynyl, or lower alkoxy, respectively, whether they appear alone or in combination with other substituents in descriptions such as hydroxyalkyl and aralkyl (where, for example, atoms in aryl groups are not counted when counting carbon atoms in an alkyl substituent).

[0102] The terms "polycyclyl", "polycycle" and "polycyclic" refer to two or more rings (e.g., cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl and / or heterocyclyl) in which two or more atoms are common to two adjacent rings, e.g., the rings are "fused rings". Each of the rings of a polycycle can be substituted or unsubstituted. In certain embodiments, each ring of a polycycle contains 3 to 10, preferably 5 to 7, atoms in the ring.

[0103] The term "sulfate" is art-recognized and refers to the group -OSO3H or a pharma- ceutically acceptable salt thereof.

[0104] The term "sulfonamide" is art-recognized and has the general formula [ka] [In the formula, R 9 and R 10 each independently represents hydrogen or hydrocarbyl. It refers to a group represented by:

[0105] The term "sulfoxide" is art-recognized and refers to the group --S(O)--.

[0106] The term "sulfonate" is art-recognized and refers to the group SO3H or a pharma- ceutically acceptable salt thereof.

[0107] The term "sulfone" is art-recognized and refers to the group -S(O)2-.

[0108] The term "substituted" refers to a moiety having a substituent replacing a hydrogen on one or more carbons of the backbone. It will be understood that "substituted" or "substituted with" includes the implicit proviso that such substitution is in accordance with the permissible valences of the substituted atom and substituent, and that the substitution results in a stable compound that does not spontaneously undergo transformation, for example, by rearrangement, cyclization, elimination, and the like. As used herein, the term "substituted" is intended to include all permissible substituents of organic compounds. In a broad aspect, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. The permissible substituents may be one or more and may be the same or different for appropriate organic compounds. For purposes of this invention, heteroatoms, such as nitrogen, may have hydrogen substituents and / or any permissible substituent of organic compounds described herein that satisfies the valence of the heteroatom. The substituents may include any of the substituents described herein, for example, halogen, hydroxyl, carbonyl (e.g., carboxyl, alkoxycarbonyl, formyl, or acyl), thiocarbonyl (e.g., thioester, thioacetate, or thioformate), alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino, amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, aralkyl, or aromatic or heteroaromatic moieties. Those skilled in the art will understand that the moieties substituted on the hydrocarbon chain can themselves be substituted, if appropriate.

[0109] The term "thioalkyl," as used herein, refers to an alkyl group substituted with a thiol group.

[0110] The term "thioester" as used herein refers to the group -C(O)SR 9 Or -SC(O)R 9 Here, R 9 represents hydrocarbyl.

[0111] The term "thioether," as used herein, corresponds to an ether where the oxygen has been replaced by a sulfur.

[0112] The term "urea" is art-recognized and has the general formula [ka] [In the formula, R 9 and R 10 each independently represents hydrogen or hydrocarbyl. It can be expressed as:

[0113] Many of the compounds useful in the methods and compositions of the present disclosure have at least one stereocenter in their structure.This stereocenter may be in R or S configuration, and the R and S notations are used according to the rules described in Pure Appl. Chem. (1976), 45, 11-30.The present disclosure contemplates all stereoisomeric forms, including enantiomeric and diastereomeric forms (including all possible mixtures of stereoisomers) of compounds, salts, prodrugs or mixtures thereof.See, for example, WO 01 / 062726.

[0114] Furthermore, certain compounds containing alkenyl groups can exist as Z (zusammen (together)) or E (entgegen (reverse)) isomers. In each case, the present disclosure includes both mixtures and the separate individual isomers.

[0115] As used herein, the term "operating conditions" refers to the conditions under which a filtration membrane is typically used or operated. For example, in certain embodiments, a filtration membrane may be designed to treat produced water (e.g., water generated as a by-product during oil and natural gas extraction), grey water (e.g., water already used in households, commercial, and industrial applications), high temperature water streams (e.g., frac water), saline streams, mine drainage, or water from industrial washes. In certain embodiments, the term "operating conditions" may refer to conditions associated with the treatment of acidic water, optionally containing suspended solids (e.g., inorganic salts). In other embodiments, the operating conditions may refer to conditions associated with the treatment of basic water, optionally containing suspended solids (e.g., inorganic salts). EXAMPLES

[0116] Having generally described the invention, the same can be more readily understood by reference to the following examples, which are provided merely for the purpose of illustrating certain aspects and embodiments of the invention and are not intended to be limiting of the invention.

[0117] Example 1 Synthesis and membrane preparation of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers Synthesis of A+(P(TFEMA-r-MAETA)). MAETA (4.00 g, 19.3 mmol) and TFEMA (4.00 g, 23.8 mmol) were dissolved in DMSO (32 mL) in that order. AIBN (0.008 g) was added to the flask. The flask was sealed and nitrogen was bubbled through the reaction mixture for 30 min to purge dissolved oxygen. The flask was then placed in an oil bath set at 60° C. and stirred at 300 rpm for 17 h. The flask was removed from the oil bath and unsealed, and 0.8 g of MEHQ was added to quench the reaction. The reaction mixture was then purified by precipitating in acetone and stirring two new portions of 1:3 volume ratio of ethanol to hexane for at least 3 h. Finally, the copolymer was dried in a vacuum oven at 60° C. for 72 h. The composition of the copolymer was determined using the ratio of protons from the two different monomer units, 1 The composition was calculated from the H-NMR spectrum (Figure 1). The calculated composition was: 41 mol% MAETA and 59 mol% TFEMA. The final conversion of this reaction was 45%.

[0118] Synthesis of S-(P(TFEMA-r-SEMA)). SEMA (4.00 g, 20.6 mmol) and TFEMA (4.00 g, 23.8 mmol) were dissolved in DMSO (32 mL) in that order. AIBN (0.008 g) was added to the flask. The flask was sealed and nitrogen was bubbled through the reaction mixture for 30 min to purge dissolved oxygen. The flask was then placed in an oil bath set at 60° C. and stirred at 300 rpm for 17 h. The flask was removed from the oil bath and unsealed, and 0.8 g of MEHQ was added to quench the reaction. The reaction mixture was then purified by precipitating with 1:3 volumetric ratio of ethanol to hexane and stirring two new portions of 2:3 volumetric ratio of ethanol to hexane for at least 3 h. Finally, the copolymer was dried in a vacuum oven at 60° C. for 72 h. The composition of the copolymer was determined using the ratio of protons from the two different monomer units, 1The composition was calculated from the H-NMR spectrum (Figure 2). The calculated composition was: 37 mol% SEMA and 63 mol% TFEMA. The final conversion of this reaction was 55%.

[0119] After both syntheses, both copolymers A+ and S- were used to prepare thin film composite membranes. Each copolymer (0.5 g) was dissolved separately in methanol (9.5 g) at about 25° C. Both copolymer solutions were passed through a 0.45 micrometer syringe filter (Whatman) and degassed in a vacuum oven for at least 1 h. Membranes were prepared by coating a thin layer of each copolymer solution onto a commercial ultrafiltration (UF) membrane using a film applicator rod, with a 10-minute solvent evaporation period between coatings. If S- was coated first, the membrane was designated SA, and if A+ was coated first, the membrane was designated AS. PS35 (PSf) ultrafiltration membranes purchased from Solecta (Oceanside, CA) were used as base membranes. After coating, the membranes were immersed in a water bath.

[0120] Additionally, coatings containing lower concentrations of top layer solution were tested. As stated above, SA and AS represent both solutions at 5 wt%. SA1 and AS1 represent 5 wt% of the first casting solution and 1 wt% of the second casting solution. SA0.2 and AS0.2 represent 5 wt% of the first casting solution and 0.2 wt% of the second casting solution. As controls, films S- and A+ with only one layer were also made.

[0121] The thickness and morphology of the membrane were determined by examining freeze-fractured cross-sections of the membrane using a scanning electron microscope. The coating layer can be observed to be approximately 0.6 micrometers thick (Figure 3).

[0122] Example 2 Water permeance and water uptake of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, the pure water flux through the membrane described in Example 1 was measured using a cell volume of 10 mL and a cell size of 4.1 cm 2 The measurements were performed using an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1000 nm. The cell was stirred at 500 rpm and the test was performed at 40 psi. After a stabilization period of at least 1 hour, permeate samples were collected and weighed over a 120 minute period. The resulting values ​​were divided by the filtration area and the duration of the experiment to obtain the permeance. The permeance values ​​were normalized by pressure to obtain the pure water permeance (Tables 1, 2, and 3). These membranes have permeance comparable to commercially available membranes for nanofiltration and ultrafiltration.

[0123] [Table 1]

[0124] [Table 2]

[0125] [Table 3]

[0126] Water uptake measurements (Table 4) were performed by utilizing polymer films approximately 40 micrometers thick. Films were prepared by mixing equal amounts (by weight) of S- and A+ copolymer solutions (both 5 wt%) on a Teflon dish, and the mixture was left overnight to dry on a nutating mixer. The films were equilibrated overnight at room temperature in deionized water, and excess water was removed by placing the films on a Kimwipe for 5 seconds, after which the samples were weighed. Dry weights were obtained by drying the same samples overnight in a vacuum oven set at 60°C.

[0127] [Table 4]

[0128] Example 3 Neutral solute rejection of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, membranes prepared as described in Example 1 were used in experiments aimed at identifying their effective pore size or size cutoff. Dye molecules and sugars were used to investigate this property. Retention experiments were performed with a cell volume of 10 mL and a 4.1 cm 2 The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1000 nm. The cell was stirred at 500 rpm and the test was carried out at 40 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After passing pure water through the membrane for at least 1 h, the cell was emptied and a 0.1 mM solution of a probe dye (vitamin B12 (B12), or riboflavin (Rib)); or a 4000 ppm aqueous solution of sugar molecules (sucrose or glucose) or glycerol was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient amount was collected for analysis by a COD kit (K-7365, CHEMetrics) or a UV-vis spectrometer (Genesys10, ThermoScientific) to calculate the solute rejection (%) (Figures 4 and 5). The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate was completely clear before switching to a new solute.

[0129] Example 4 Salt Rejection of Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly(2-sulfoethyl methacrylate) (S-) Used as Amphiphilic Polyelectrolyte Complex (APEC) Multilayers In this example, membranes prepared as described in Example 1 were used in experiments to determine their salt retention properties. Different salts at different concentrations were used to investigate this property, and their concentrations were easily measured by a standard conductivity probe. The retention experiments were performed with a cell volume of 10 mL and a 4.1 cm 2The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​100 μm. The cell was stirred at 500 rpm and the test was carried out at 40 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After passing pure water through the membrane for at least 1 h, the cell was emptied and an aqueous solution of the probe salt was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient amount was collected for analysis by conductivity probe and to calculate salt rejection (%) (Figures 6-14). The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate volume reached 1 mL before switching to a new salt solution.

[0130] Example 5 Antifouling properties of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, two membranes, S- and SA, prepared as described in Example 1, were used in the experiments to determine their anti-fouling properties. The experiments were carried out with a cell volume of 10 mL and a 4.1 cm 2 The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1000 nm. The cell was stirred at 500 rpm. The feed solution consisted of a 1500 ppm oil-in-water emulsion (9:1 ratio of soybean oil:DC193 surfactant (obtained from Dow-Corning)) prepared by mixing the oil, water, and surfactant in a blender at high rpm for 3 minutes.

[0131] Example 6 Synthesis and membrane preparation of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(methacrylic acid) (M-) used as amphiphilic polyelectrolyte complex (APEC) multilayers A+ was synthesized using the same protocol as in Example 1 and used the same copolymer (Figure 1).

[0132] Synthesis of M-(P(TFEMA-r-MAA)). MAA (10.00 g) and TFEMA (10.00 g) were dissolved in DMSO (100 mL) in that order. AIBN (0.02 g) was added to the flask. The flask was sealed and nitrogen was bubbled through the reaction mixture for 30 min to purge dissolved oxygen. It was then placed in an oil bath set at 55° C. and the flask was stirred at 300 rpm for 4 h. The flask was removed from the oil bath and unsealed, and 2 g of MEHQ in 10 mL of DMSO was added to quench the reaction. The reaction mixture was then purified by precipitating with 1:3 volumetric ratio of ethanol to hexane and stirring for at least 8 h with two new portions of 1:3 volumetric ratio of ethanol to hexane. Finally, the copolymer was dried in a vacuum oven at 50° C. for 120 h. The composition of the copolymer was determined using the ratio of protons from the two different monomer units, 1 The composition was calculated from the H-NMR spectrum (Figure 16). The calculated composition was: 59 mol% MAA and 41 mol% TFEMA. The final conversion of this reaction was 35%.

[0133] After both syntheses, both copolymers A+ and M- were used to prepare thin film composite membranes. Each copolymer (0.5 g) was dissolved separately in methanol (9.5 g) at about 25° C. Both copolymer solutions were passed through a 0.45 micrometer syringe filter (Whatman) and degassed in a vacuum oven for at least 1 h. Membranes were prepared by coating a thin layer of each copolymer solution onto a commercial ultrafiltration (UF) membrane using a film applicator rod, with a 10 min solvent evaporation period between coatings. If M- was coated first, the membrane was designated MA, and if A+ was coated first, the membrane was designated AM. PS35 (PSf) ultrafiltration membrane purchased from Solecta (Oceanside, CA) was used as the base membrane. After coating, the membrane was immersed in a water bath.

[0134] The thickness and morphology of the membrane was determined by examining the freeze-fractured cross-sections of the membrane using a scanning electron microscope. The coating layer can be observed to be approximately 0.4 micrometers thick (Figure 17).

[0135] Example 7 Water permeance of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(methacrylic acid) (M-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, the pure water permeation flux through the membrane AM described in Example 6 was measured using a cell volume of 10 mL and a cell volume of 4.1 cm 2 The measurements were performed using an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1.5 L / m. The cell was stirred at 500 rpm and the test was performed at 40 psi. After a stabilization period of at least 1 hour, permeate samples were collected and weighed over a 120-minute period. The resulting values ​​were divided by the filtration area and the duration of the experiment to obtain the permeate flux. The permeate flux values ​​were pressure normalized to 1.5 L / m. 2 A pure water permeance of .h.bar was obtained.

[0136] Example 8 Neutral solute rejection of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(methacrylic acid) (M-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, membranes prepared as described in Example 6 were used in experiments aimed at identifying their effective pore size or size cutoff. Vitamin B12 was used to investigate this property. Retention experiments were performed with a cell volume of 10 mL and 4.1 cm 2 The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​100 μm. The cell was stirred at 500 rpm and tested at 40 psi. To minimize concentration polarization effects, the cell was stirred at 500 rpm. After passing pure water through the membrane for at least 1 h, the cell was emptied and an aqueous solution of 0.1 mM of the probe dye (vitamin B12 (B12)) was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient volume was collected for analysis by UV-vis spectrometer (Genesys10, ThermoScientific), and the solute rejection was calculated to be 95.3%.

[0137] Example 9 Synthesis and membrane preparation of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(methacrylic acid) (M-) used as amphiphilic polyelectrolyte complex (APEC) blends A+ and M- were synthesized using the same protocol as in Examples 1 and 6, and the same copolymers were used (Figures 1 and 16, respectively).

[0138] After both syntheses, both copolymers A+ and M- were used to prepare thin film composite membranes. Each copolymer (0.5 g) was dissolved separately in methanol (9.5 g) at about 25° C. Both solutions were combined to make solutions with different molar ratios of ionizable / charged monomer units, and all solutions were passed through a 0.45 micrometer syringe filter (Whatman) and degassed in a vacuum oven for at least 1 hour. Membranes were prepared by coating a thin layer of the combined solution onto a commercial ultrafiltration (UF) membrane using a film applicator rod. A PS35 (PSf) ultrafiltration membrane purchased from Solecta (Oceanside, CA) was used as the base membrane. After coating, the membrane was immersed in a water bath.

[0139] The thickness and morphology of the membrane was determined by examining freeze-fracture cross-sections of the membrane using a scanning electron microscope. The coating layer can be observed to be approximately 3 micrometers thick (Figure 18).

[0140] Example 10 Water permeance of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(methacrylic acid) (M-) used as amphiphilic polyelectrolyte complex (APEC) blends In this example, the pure water flux through the membrane described in Example 9 was measured using a cell volume of 10 mL and a cell size of 4.1 cm 2 The measurements were performed using an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1000 nm. The cell was stirred at 500 rpm and the test was performed at 40 psi. After a stabilization period of at least 1 hour, permeate samples were collected and weighed over a 120 minute period. The resulting values ​​were divided by the filtration area and the duration of the experiment to obtain the permeance. The permeance values ​​were normalized by pressure to obtain the pure water permeance (Figure 19). These membranes have permeance comparable to commercial membranes for nanofiltration and ultrafiltration.

[0141] Example 11 Neutral solute rejection of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(methacrylic acid) (M-) used as amphiphilic polyelectrolyte complex (APEC) blends In this example, membranes prepared as described in Example 9 were used in experiments aimed at identifying their effective pore size or size cutoff. Vitamin B12 was used to investigate this property. Retention experiments were performed with a cell volume of 10 mL and a 4.1 cm 2 The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​100 μm. The cell was stirred at 500 rpm and the test was performed at 40 psi. To minimize concentration polarization effects, the cell was stirred at 500 rpm. After passing pure water through the membrane for at least 1 h, the cell was emptied and an aqueous solution of 0.1 mM of the probe dye (vitamin B12 (B12)) was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient volume was collected for analysis by UV-vis spectrometer (Genesys10, ThermoScientific) and to calculate the solute rejection (Figure 20).

[0142] Example 12 Salt Rejection of Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly(methacrylic acid) (M-) Used as Amphiphilic Polyelectrolyte Complex (APEC) Blends In this example, membranes prepared as described in Example 9 were used in experiments to determine their salt retention properties. Different salts at different concentrations were used to investigate this property, and their concentrations were easily measured by a standard conductivity probe. The retention experiments were performed with a cell volume of 10 mL and a 4.1 cm 2 The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1000 nm. The cell was stirred at 500 rpm and the test was carried out at 40 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After passing pure water through the membrane for at least 1 h, the cell was emptied and an aqueous solution of the probe salt was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient amount was collected for analysis by conductivity probe and to calculate salt rejection (%) (Figures 21-23). ​​The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate volume reached 1 mL before switching to a new salt solution.

[0143] Example 13 Synthesis and membrane preparation of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A2+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A2+) is synthesized using a higher content of TFEMA. The anionic copolymer is the same S-copolymer as described in Example 1.

[0144] Synthesis of A2+(P(TFEMA-r-MAETA)). MAETA (3.50 g) and TFEMA (6.50 g) were dissolved in DMSO (40 mL) in that order. AIBN (0.01 g) was added to the flask. The flask was sealed and nitrogen was bubbled through the reaction mixture for 30 min to purge dissolved oxygen. The flask was then placed in an oil bath set at 60° C. and stirred at 300 rpm for 17 h. The flask was removed from the oil bath and unsealed, and 1.0 g of MEHQ was added to quench the reaction. The reaction mixture was then purified by precipitating in acetone and stirring two fresh portions of acetone for at least 3 h, followed by two fresh portions of DI water for at least 3 h. Finally, the copolymer was dried in a vacuum oven at 60° C. for 72 h. The composition of the copolymer was determined using the ratio of protons from the two different monomer units, 1 Calculated from the H-NMR spectrum (Figure 24). The calculated composition was: 34 wt% MAETA and 66 wt% TFEMA. The final conversion of this reaction was 35%.

[0145] Synthesis of S-(P(TFEMA-r-SEMA)). SEMA (4.00 g, 20.6 mmol) and TFEMA (4.00 g, 23.8 mmol) were dissolved in DMSO (32 mL) in that order. AIBN (0.008 g) was added to the flask. The flask was sealed and nitrogen was bubbled through the reaction mixture for 30 min to purge dissolved oxygen. The flask was then placed in an oil bath set at 60° C. and stirred at 300 rpm for 17 h. The flask was removed from the oil bath and unsealed, and 0.8 g of MEHQ was added to quench the reaction. The reaction mixture was then purified by precipitating with 1:3 volumetric ratio of ethanol to hexane and stirring two new portions of 2:3 volumetric ratio of ethanol to hexane for at least 3 h. Finally, the copolymer was dried in a vacuum oven at 60° C. for 72 h. The composition of the copolymer was determined using the ratio of protons from the two different monomer units, 1 The composition was calculated from the H-NMR spectrum (Figure 25). The calculated composition was: 37 mol% SEMA and 63 mol% TFEMA. The final conversion of this reaction was 55%.

[0146] After both syntheses, thin film composite membranes were prepared with both copolymers A2+ and S-. Each copolymer (0.5 g) was dissolved separately in methanol (9.5 g) at about 25° C. Both copolymer solutions were passed through a 0.45 micrometer syringe filter (Whatman) and degassed in a vacuum oven for at least 1 h. Membranes were prepared by coating a thin layer of each copolymer solution onto a commercial ultrafiltration (UF) membrane using a film applicator rod, with a 10-minute solvent evaporation period between coatings. If S- was coated first, the membrane was designated SA2, and if A2+ was coated first, the membrane was designated A2S. PS35 (PSf) ultrafiltration membrane purchased from Solecta (Oceanside, CA) was used as the base membrane. After coating, the membrane was immersed in a water bath.

[0147] The thickness and morphology of the membrane was determined by examining the freeze-fractured cross-sections of the membrane using a scanning electron microscope. The coating layer can be observed to be approximately 0.5 micrometers thick (Figure 26).

[0148] Example 14 Water permeance of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A2+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, the pure water flux through the membrane described in Example 13 was measured using a cell volume of 10 mL and a cell size of 4.1 cm 2 The measurements were performed using an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​8.5 ± 0.9 L / m. The cell was stirred at 500 rpm and the test was performed at 40 psi. After a stabilization period of at least 1 hour, permeate samples were collected and weighed over a 120-minute period. The resulting value was divided by the filtration area and the duration of the experiment to obtain the permeance. The permeance value was normalized by pressure to obtain the pure water permeance. The permeance of the A2S was 8.5 ± 0.9 L / m. 2 On the other hand, the permeance of A2+ (coated with A2+ only) was 59±11 L / m 2 These membranes have permeances comparable to commercial membranes for nanofiltration and ultrafiltration.

[0149] Example 15 Neutral solute rejection of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A2+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, membranes prepared as described in Example 13 were used in experiments aimed at identifying their effective pore size or size cutoff. Dye molecules and sugars were used to investigate this property. Retention experiments were performed with a cell volume of 10 mL and a 4.1 cm 2The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​100 μm. The cell was stirred at 500 rpm and the test was performed at 40 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After passing pure water through the membrane for at least 1 h, the cell was emptied and a 0.1 mM solution of a probe dye (vitamin B12 (B12), or riboflavin (Rib)); or a 4000 ppm aqueous solution of sugar molecules (sucrose or glucose) or glycerol was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient amount was collected for analysis by a COD kit (K-7365, CHEMetrics) or a UV-vis spectrometer (Genesys10, ThermoScientific) to calculate the solute rejection (%) (Figures 27-28). The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate was completely clear before switching to a new solute.

[0150] Example 16 Salt Rejection of Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride (A2+) and Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly(2-sulfoethyl methacrylate) (S-) Used as Amphiphilic Polyelectrolyte Complex (APEC) Multilayers In this example, membranes prepared as described in Example 13 were used in experiments to determine their salt retention properties. Different salts at different concentrations were used to investigate this property, and their concentrations were easily measured by a standard conductivity probe. The retention experiments were performed with a cell volume of 10 mL and a 4.1 cm 2 The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1000 nm. The cell was stirred at 500 rpm and the test was carried out at 40 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After passing pure water through the membrane for at least 1 h, the cell was emptied and an aqueous solution of the probe salt was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient amount was collected for analysis by conductivity probe and to calculate salt rejection (%) (Figures 29-31). The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate volume reached 1 mL before switching to a new salt solution.

[0151] Example 17 Synthesis and membrane preparation of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S2-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S2-) is synthesized using a higher content of TFEMA. The cationic copolymer is the same A+ copolymer as described in Example 1.

[0152] Synthesis of A+(P(TFEMA-r-MAETA)). MAETA (4.00 g, 19.3 mmol) and TFEMA (4.00 g, 23.8 mmol) were dissolved in DMSO (32 mL) in that order. AIBN (0.008 g) was added to the flask. The flask was sealed and nitrogen was bubbled through the reaction mixture for 30 min to purge dissolved oxygen. The flask was then placed in an oil bath set at 60° C. and stirred at 300 rpm for 17 h. The flask was removed from the oil bath and unsealed, and 0.8 g of MEHQ was added to quench the reaction. The reaction mixture was then purified by precipitating in acetone and stirring two new portions of 1:3 volume ratio of ethanol to hexane for at least 3 h. Finally, the copolymer was dried in a vacuum oven at 60° C. for 72 h. The composition of the copolymer was determined using the ratio of protons from the two different monomer units, 1 The composition was calculated from the H-NMR spectrum (Figure 32). The calculated composition was: 41 mol% MAETA and 59 mol% TFEMA. The final conversion of this reaction was 45%.

[0153] Synthesis of S2-(P(TFEMA-r-SEMA)). SEMA (1.75 g) and TFEMA (3.25 g) were dissolved in DMSO (20 mL) in that order. AIBN (0.005 g) was added to the flask. The flask was sealed and nitrogen was bubbled through the reaction mixture for 30 min to purge dissolved oxygen. The flask was then placed in an oil bath set at 60° C. and stirred at 300 rpm for 17 h. The flask was removed from the oil bath and unsealed, and 0.5 g of MEHQ was added to quench the reaction. The reaction mixture was then purified by precipitating in DI water and stirring two new portions of DI water for at least 3 h. The copolymer was dried in a vacuum oven at 60° C. for 48 h. The copolymer was then purified by stirring two new portions of hexane for at least 3 h. Finally, the copolymer was dried in a vacuum oven at 60° C. for 72 h. The composition of the copolymer was determined using the ratio of protons from the two different monomer units: 1 The composition was calculated from the H-NMR spectrum (Figure 33). The calculated composition was: 30 mol% SEMA and 70 mol% TFEMA. The final conversion of this reaction was 21%.

[0154] After both syntheses, thin film composite membranes were prepared using both copolymers A+ and S2-. Each copolymer (0.5 g) was dissolved separately in methanol (9.5 g) at about 25 °C. Both copolymer solutions were degassed in a vacuum oven for at least 1 h. Membranes were prepared by coating a thin layer of each copolymer solution onto a commercial ultrafiltration (UF) membrane using a film applicator rod, with a 10 min solvent evaporation period between coatings. If S2- was coated first, the membrane was named S2A, and if A+ was coated first, the membrane was named AS2. PS35 (PSf) ultrafiltration membrane purchased from Solecta (Oceanside, CA) was used as the base membrane. After coating, the membrane was immersed in a water bath.

[0155] The thickness and morphology of the membrane was determined by examining the freeze-fractured cross-sections of the membrane using a scanning electron microscope. The coating layer can be observed to be approximately 0.4 micrometers thick (Figure 34).

[0156] Example 18 Water permeance of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S2-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, the pure water flux through the membrane described in Example 17 was measured using a 10 mL cell volume and 4.1 cm 2 The measurements were performed using an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​4.7 ± 0.8 L / m. The cell was stirred at 500 rpm and the test was performed at 40 psi. After a stabilization period of at least 1 hour, permeate samples were collected and weighed over a 120-minute period. The resulting value was divided by the filtration area and the duration of the experiment to obtain the permeance. The permeance values ​​were normalized by pressure to obtain the pure water permeance. The permeance of AS2 was 4.7 ± 0.8 L / m. 2 The permeance of S2- (only S2- is coated) was 98±17 L / m 2 These membranes have permeances comparable to commercial membranes for nanofiltration and ultrafiltration.

[0157] Example 19 Neutral solute rejection of poly(2,2,2-trifluoroethyl methacrylate)-random-poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and poly(2,2,2-trifluoroethyl methacrylate)-random-poly(2-sulfoethyl methacrylate) (S-) used as amphiphilic polyelectrolyte complex (APEC) multilayers In this example, membranes prepared as described in Example 17 were used in experiments aimed at identifying their effective pore size or size cutoff. Dye molecules were used to characterize this. Retention experiments were performed with a cell volume of 10 mL and 4.1 cm 2The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​100 μm. The cell was stirred at 500 rpm and the test was carried out at 40 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After passing pure water through the membrane for at least 1 h, the cell was emptied and a 0.1 mM aqueous solution of the probe dye (vitamin B12 (B12), or riboflavin (Rib)) was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient amount was collected for analysis by UV-vis spectrometer (Genesys10, ThermoScientific) and to calculate the solute rejection (%) (Figure 35). The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate was completely clear before switching to a new solute.

[0158] Example 20 Salt Rejection of Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (A+) and Poly(2,2,2-trifluoroethyl methacrylate)-Random-Poly(2-sulfoethyl methacrylate) (S2-) Used as Amphiphilic Polyelectrolyte Complex (APEC) Multilayers In this example, membranes prepared as described in Example 17 were used in experiments to determine their salt retention properties. Different salts at different concentrations were used to investigate this property, and their concentrations were easily measured by a standard conductivity probe. The retention experiments were performed with a cell volume of 10 mL and 4.1 cm 2 The experiments were carried out in an Amicon 8010 stirred dead-end filtration cell (Millipore) with an effective filtration area of ​​1000 nm. The cell was stirred at 500 rpm and the test was carried out at 40 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After passing pure water through the membrane for at least 1 h, the cell was emptied and an aqueous solution of the probe salt was placed in the cell. After discarding the first 1 mL to avoid contamination with pure water, a sufficient amount was collected for analysis by conductivity probe and to calculate the salt rejection (%) (Figures 36-38). The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate volume reached 1 mL before switching to a new salt solution.

[0159] INCORPORATION BY REFERENCE All publications and patents mentioned herein are incorporated herein by reference in their entirety as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. In case of conflict, the present application, including any definitions herein, will control.

[0160] Equivalent Although specific embodiments of the present invention have been discussed, the above specification is illustrative and not restrictive. Many variations of the present invention will become apparent to those skilled in the art upon review of this specification and the following claims. The full scope of the present invention should be determined by reference to the claims and their full scope of equivalents, as well as the specification and such variations.

Claims

1. A composite film comprising a porous support and a selective layer containing a first copolymer and a second copolymer, The first copolymer comprises a first plurality of hydrophobic repeating units and a plurality of cationic repeating units; The second copolymer comprises a second plurality of hydrophobic repeating units and a plurality of anionic repeating units; A composite membrane in which the first copolymer and the second copolymer are essentially insoluble in water.

2. The composite membrane according to claim 1, wherein the first copolymer and the second copolymer are insoluble in water under operating conditions.

3. The composite film according to claim 1, which is a thin film composite film.

4. The composite film has a thickness of about 20 μm to about 1,000 μm, and / or The composite film according to claim 1, wherein the selected layer has a thickness of about 30 nm to about 5 μm.

5. The plurality of cationic repeating units are at least partially positively charged in water, and / or The composite film according to claim 1, wherein the plurality of anionic repeating units are at least partially negatively charged in water.

6. The composite film according to claim 1, wherein the selected layer essentially consists of the first copolymer and the second copolymer.

7. The first copolymer comprises about 5 to 80% by weight of the plurality of cationic repeating units, or The composite film according to claim 1, wherein the first copolymer comprises about 5 to 80 mol% of the plurality of cationic repeating units.

8. The second copolymer comprises about 5 to 80% by weight of the plurality of anionic repeating units, or The composite film according to claim 1, wherein the second copolymer comprises about 5 to 80 mol% of the plurality of anionic repeating units.

9. The first copolymer has an average molar mass of at least 30,000 g / mol, and / or The composite film according to claim 1, wherein the second copolymer has an average molar mass of at least 30,000 g / mol.

10. The composite film according to claim 1, wherein the first copolymer and the second copolymer are sequentially laminated on a porous support.

11. The first copolymer is a first layer, the second copolymer is a second layer, the first copolymer layer is on the second copolymer layer, and the second copolymer layer is in contact with a porous support, or The composite film according to claim 10, wherein the second copolymer is a first layer, the first copolymer is a second layer, the second copolymer layer is on the first copolymer layer, and the first copolymer layer is in contact with a porous support.

12. The composite film according to claim 1, wherein the first copolymer and the second copolymer are mixed together on a porous support to form a homogeneous layer on the porous support.

13. The composite film according to claim 1, wherein the first plurality of hydrophobic repeating units include repeating units derived from acrylate, acrylamide, styrene, or hydrophobic amino acids.

14. The composite film according to claim 1, wherein the first plurality of hydrophobic repeating units include repeating units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA), pentafluoropropyl methacrylate, heptafluorobutyl, pentafluorophenyl methacrylate, styrene, methyl methacrylate, acrylonitrile, 2-chloroethyl methacrylate, 2-bromoethyl methacrylate, and allyl methacrylate.

15. The composite film according to claim 1, wherein the first plurality of hydrophobic repeating units include repeating units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA).

16. The composite film according to claim 1, wherein the second plurality of hydrophobic repeating units include repeating units derived from acrylate, acrylamide, styrene, or hydrophobic amino acids.

17. The composite film according to claim 1, wherein the second plurality of hydrophobic repeating units include repeating units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA), pentafluoropropyl methacrylate, heptafluorobutyl, pentafluorophenyl methacrylate, styrene, methyl methacrylate, acrylonitrile, 2-chloroethyl methacrylate, 2-bromoethyl methacrylate, and allyl methacrylate.

18. The composite film according to claim 1, wherein the second plurality of hydrophobic repeating units include repeating units derived from 2,2,2-trifluoroethyl methacrylate (TFEMA).

19. The composite film according to claim 1, wherein the plurality of cationic repeating units include repeating units derived from acrylates, acrylamides, styrenes, and vinyl monomers, which are substituted with amines, pyridinium, imidazolium, phosphonium, or pyrrolidinium.

20. The composite film according to claim 1, wherein the plurality of cationic repeating units include repeating units derived from [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MAETA), [3(methacryloylamino)propyl]trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, (3-acrylamidopropyl)trimethylammonium chloride, 4-vinylbenzyl(triphenyl)phosphonium chloride, (vinylbenzyl)trimethylammonium chloride methacrylate, 3-vinylaniline, 4-vinylaniline, 2-isopropenylaniline, N-(3-aminopropyl)methacrylamide hydrochloride, N-vinylimidazolium, 1-allyl-3-vinylimidazolium, l-allyl-2methyl-5-vinylpyridinium, l-allyl-5-vinylpyridinium, or 1-methyl-1-(1-vinylcyclohexyl)pyrrolidinium iodide.

21. The composite film according to claim 1, wherein the plurality of cationic repeating units include repeating units derived from 2-(methacryloyloxy)ethyl]trimethylammonium chloride.

22. The composite film according to claim 1, wherein the plurality of anionic repeating units include repeating units derived from acrylates, acrylamides, styrenes, or vinyl monomers substituted with carboxylic acids, sulfonates, or phosphates.

23. The aforementioned plurality of anionic repeating units are methacrylic acid (MAA), 2-sulfoethyl methacrylate (SEMA), L-tryptophan-methacrylamide, D-tryptophan-methacrylamide, L or D-tryptophan-acrylamide, L or D-alanine-methacrylamide, L or D-alanine-acrylamide, L or D-valine-methacrylamide, L or D-valine-acrylamide, L or D-isoleucine-methacrylamide, L or D-isoleucine-acrylamide Amides, L or D-allo-isoleucine-methacrylamide, L or D-allo-isoleucine-acrylamide, L or D-methionine-methacrylamide, L or D-methionine-acrylamide, L or D-phenylalanine-methacrylamide, L or D-phenylalanine-acrylamide, L or D-tyrosine-methacrylamide, L or D-tyrosine-acrylamide, L or D-histazine-methacrylamide, L or D-histazine-acrylamide, L or D- Glutamic acid-methacrylamide, L or D-glutamic acid-acrylamide, L or D-aspartic acid-acrylamide, L or D-aspartic acid-methacrylamide, acrylic acid, 2-carboxyethyl acrylate, mono-2-(methacryloyloxy)ethyl succinate, mono-2-(methacryloyloxy)ethyl maleate, sodium 4-vinylbenzenesulfonate, 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid The composite film according to claim 1, comprising repeating units derived from sodium phosphate, 2-acrylamido-2-methyl-1-propanesulfonic acid, potassium 3-sulfopropyl acrylate, potassium 3-sulfopropyl methacrylate, vinylbenzoic acid, 4-vinylbenzoic acid, 2-vinylbenzoic acid, 4-(2-propenyl)benzoic acid, sodium 2-methyl-2-propene-1-sulfonate, sodium vinylsulfonate, vinylphosphonic acid, or (4-ethenylphenyl)methylphosphonic acid.

24. The composite film according to claim 1, wherein the plurality of anionic repeating units include repeating units derived from 2-sulfoethyl methacrylate or methacrylic acid.

25. The composite film according to claim 1, wherein the first copolymer and / or the second copolymer is a statistical copolymer.

26. The first copolymer and / or the second copolymer is a random copolymer, or The first copolymer and / or the second copolymer is a block copolymer, or The composite film according to claim 1, wherein the first copolymer and / or the second copolymer is a graft copolymer or a comb copolymer.

27. The composite membrane according to claim 1, wherein the effective pore diameter of the composite membrane is smaller than the effective pore diameter of a membrane prepared by coating the first copolymer alone or the second copolymer alone on the same porous support.

28. The composite film according to claim 1, wherein the first copolymer and / or the second copolymer are crosslinked.

29. A method for separating a solute from a solution, comprising contacting the solution with a composite membrane according to any one of claims 1 to 28.

30. The method according to claim 29, wherein the solute is a salt.

31. A method for producing a composite film according to any one of claims 1 to 28, comprising coating a porous support with the first copolymer and coating a second copolymer, thereby producing a composite film.

32. The first copolymer and the second copolymer are sequentially coated onto a porous support layer, thereby forming a two-layer film, or The method according to claim 31, wherein the first copolymer and the second copolymer are coated onto a porous support layer as a blend to form a blend film.

33. The method according to claim 31, wherein the first copolymer and / or the second copolymer are dissolved in a protic solvent before application.

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