amphoterically charged copolymer membrane

Abstract

A linear / random / statistical copolymer comprising the following three types of monomer units is disclosed: a hydrophobic monomer unit, an amphoteric monomer unit, and a charged or ionized monomer unit. Additionally, a thin film composite in which a selective layer is composed of the copolymer disclosed herein and a method of using the same are disclosed.

Description

Technology Field

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 846,014 filed on May 10, 2019, the contents of which are incorporated herein by reference in their entirety.

[0003] Government support

[0004] The present invention was made with government support pursuant to grants No. 1508049 and 1553661 granted by the National Science Foundation. The U.S. government retains specific rights to the present invention. Background Technology

[0005] Nanofiltration (NF) membranes are defined by an effective pore size of approximately 1 nm. They are typically used to remove divalent salts from water and wastewater streams in applications such as water softening. Almost all commercially available NF membranes today feature a cross-linked polyamide selective layer manufactured by interfacial polymerization. The chemical properties of this selective layer have been utilized for decades, and as a result, these commercial membranes are highly optimized and provide significantly high water permeability along with the desired divalent salt rejection rate.

[0006] However, polyamide selective layers also have significant limitations inherent in their chemical structure, such as a lack of antifouling and chlorine resistance. Recently, zwitterionics have been extensively studied in the membrane field due to their hydrophilicity and antifouling properties. Zwitterionic amphiphilic copolymers (ZACs) have been documented to self-assemble to form microstructures. Furthermore, when ZACs are used as selective membrane layers, antifouling membranes with an effective pore size of approximately 1–2 nm can be obtained. These membranes have also been shown to exhibit high chlorine resistance.

[0007] However, an important characteristic of these membranes was that they exhibited a relatively low salt removal rate due to the overall neutral chemical properties of the membrane selector layer. Therefore, although ZAC provides an effective pore size close to that of NF membranes as well as expected antifouling and antichlorine properties, its removal rate profile is not sufficient to replace commercially available NF membranes in most applications. Consequently, there is a need to develop high-performance membranes that do not have the aforementioned disadvantages.

[0008] A copolymer comprising a plurality of each of the following three types of monomer units is provided herein: a hydrophobic monomer unit, an amphoteric monomer unit, and a charged or ionized monomer unit. Preferably, the copolymer is linear, statistical, or random, or all of these. A thin film composite membrane is also provided in which a selective layer is composed of these copolymers. These membranes may be used for various aqueous separations, including but not limited to water treatment, water softening, wastewater treatment, and the separation and purification of organic molecules in aqueous solutions. Due to the chemical properties of these copolymers, the membranes exhibit increased resistance to chemical degradation by chlorine and strong resistance to contamination.

[0009] In one embodiment, a copolymer comprising a plurality of amphoteric monomer units, a plurality of charged / ionized monomer units, and a plurality of hydrophobic monomer units is provided herein.

[0010] In another embodiment, a thin film composite comprising a porous support and a polymer material thin film is provided in the present invention, wherein the pore size of the porous support is larger than the effective pore size of the polymer material thin film.

[0011] In another embodiment, a size-based selection or exclusion method is provided herein, comprising the step of contacting a solution containing a plurality of uncharged organic molecules of different sizes with a thin film composite disclosed herein.

[0012] In another embodiment, a charge-based selection or exclusion method is provided herein, comprising the step of contacting a solution containing a plurality of salts with a thin film composite disclosed herein. Brief explanation of the drawing

[0013] Fig. 1 Charged Zwitterionic Amphiphilic Copolymer (CZAC), P(TFEMA- r -SBMA- r This is a schematic diagram illustrating the polymer structure / chemistry of -MAA and the self-assembly when coated on a support to form a membrane selective layer characterized by hydrophilic domains of about 1 to 2 nm that function as a network of effective nanochannels lined with carboxylate groups. Fig. 2 PTFEMA-SBMA-MAA-B1, representing copolymerization 1 Plot the H NMR spectrum. Fig. 3 PTFEMA-SBMA-MAA-B2, representing copolymerization 1 Plot the H NMR spectrum. Fig. 4a This shows an SEM image of an uncoated Trisep UE50 film. Fig. 4b This shows an SEM image of a PTFEMA-SBMA-MAA-B1 TFC membrane. Fig. 4c This shows an SEM image of a PTFEMA-SBMA-MAA-B2 TFC membrane. Fig. 5a This is a bar graph showing the removal rates of neutral (Rib, RH, and VB12) and anionic (Na2SO4, MO, AB45) solutes by PTFEMA-SBMA membrane, PTFEMA-SBMA-MAA-B1 membrane, and PTFEMA-SBMA-MAA-B2 membrane. Fig. 5b This is a graph showing the removal rate of sugars and dyes by the membrane prepared as described in Example 2B. Fig. 6aThis is a bar graph showing the removal rates of various salts at concentrations of 1 mM and 5 mM by PTFEMA-SBMA membrane, PTFEMA-SBMA-MAA-B1 membrane, and PTFEMA-SBMA-MAA-B2 membrane. Fig. 6b Na2SO4(C at pH varying due to PTFEMA-SBMA-MAA-B1) 공급 This is a graph showing the removal rate of =5 mM. Fig. 6c This is a bar graph showing the removal rates of PTFEMA-SBMA-MAA-B2 of various salts at concentrations of 1 mM and 5 mM. The removal rates are DSPM(C 공급 In the case where = 1 mM: D 공극 = 1.95 nm, δ 유효 =20 μm, and X=21.4 mM. C 공급 For = 5 mM: D 공극 = 1.95 nm, δ 유효 Fit to =20 μm, and X=60.4 mM). Fig. 7a This is a graph showing the removal rate of various neutral dyes. Fig. 7b This is a graph showing the removal rates of various anionic dyes and Na2SO4. Fig. 8a This is a graph showing the oil emulsion resistance of a PTFEMA-SBMA-MAA-B2 membrane (stabilized by Span80 neutral surfactant). Fig. 8b This is a graph showing the emulsion-resistant fouling properties of a PTFEMA-SBMA-MAA-B2 membrane (stabilized by DC 193 neutral surfactant). Fig. 8c This is a graph showing the antifouling properties of the CZAC membrane against a mixture of BSA and CaCl2 (1.0 g / L BSA, 10 mM CaCl2, pH=6.3, and Jo 5.4 LMH). A commercially available NF membrane was used as a reference. Fig. 8dThis is a graph showing the antifouling properties of the CZAC membrane against a mixture of humic acid and alginate (1 g / L each, pH 4.5, Jo = 7.0 LMH). A commercially available NF membrane was used as the reference point. Fig. 9 This is a graph showing the permeance of PTSBMA-SBMA-MAA before and after Clorox treatment. Fig. 10 is an IR spectrum showing the effect of chlorine treatment on the PTFEMA-SBMA-MAA-B2 bonding chemistry. FTIR spectra obtained before and after 16 hours of immersion in a 2,000 ppm sodium hypochlorite solution at pH 4.5. Fig. 11 This is a graph showing the convertible flux behavior observed after PTFEMA-SBMA-MAA-B1 is rearranged upon exposure to PBS solution. Fig. 12a is NaOH (aq) This is a bar graph showing the rearrangement of the PTFEMA-SBMA-MAA-B1 membrane by (pH=11). Fig. 12b is NaOH (aq) This is a bar graph showing the permeability of the PTFEMA-SBMA membrane during filtration at (pH=11). Fig. 13 NaOH (aq) This is a bar graph showing the removal rates of Vitamin B12 and Na2SO4 before and after rearrangement through treatment. Fig. 14 is a bar graph showing membrane permeability according to filtration ID (in Table 5). Fig. 15 This is a bar graph showing the permeability of a PTFEMA-SBMA-MAA membrane rearranged in response to a calcium-containing basic solution. Fig. 16 This is a graph showing the correlation between the composition of the reaction mixture and the composition of the terpolymer produced, which appears close to the random monomer sequence. Specific details for implementing the invention

[0014] A membrane is disclosed that combines NF-type selectivity, antifouling, and chlorine resistance by influencing the self-assembly properties of ZAC and modifying this group of polymers to improve the salt removal rate. Specifically, a membrane is disclosed that is prepared by an extended manufacturing technique using a charged zwitterionic amphiphilic copolymer (CZAC) and a CZAC select layer. The CZAC is a random or statistical terpolymer of the following three types of monomers: a hydrophobic monomer, an amphoteric monomer, and an acidic / ionized monomer. Preferably, the copolymer is linear, random, and statistical. The random / statistical structure of the copolymer and the attractive forces between the zwitterionic monomers impart to this terpolymer the ability to self-assemble to form a bicontinuous network composed of hydrophilic (amphiphotic / charged) and hydrophobic nanodomains of 1 to 2 nm. Water and other solutes pass through hydrophilic domains that function as an effective network of charged-walled nanochannels. This allows the terpolymer to be used as a membrane selector layer. The hydrophilic nanochannels are net-charged due to the ionization of contained functional groups (e.g., deprotonation of acidic repeating units, protonation of amine groups, dissociation of sulfonate groups), which increases the removal rate of charged solutes and salt ions. Due to the presence of amphoteric ionic groups, these membranes exhibit high antifouling properties. Using novel polymer chemistry enables high chlorine resistance without change in performance when exposed to chlorine at 32,000 ppm.

[0015] A group of polymer materials comprising at least three repeating units is disclosed:

[0016] 1. A bicontinent network of hydrophilic / water-permeable nano-domains that functions as a permeation pathway to water and aqueous solutions containing solutes smaller than the domain size, which is preferably typically less than 5 nm, preferably 0.6 to 3 nm, and more preferably 0.6 to 2 nm.

[0017] 2. Charged or ionized repeating units, which impart charge-based selectivity and ion retention properties through a Donnan exclusion mechanism.

[0018] 3. Relatively hydrophobic repeating units, which limit the swelling of the polymer in water and impart stability to the polymer in an aqueous environment. It is preferable that these hydrophobic repeating units be derived from monomers that are insoluble in water and have a glass transition temperature higher than the operating temperature (e.g., higher than room temperature).

[0019] A polymer, referred to as a charged amphoteric copolymer (CZAC), can be synthesized from vinyl monomers (e.g., acrylates, methacrylates, acrylamides, styrene derivatives, acrylonitriles) using a well-known polymerization method (e.g., free radical polymerization). The polymer contains three types of repeating units in an approximately random / statistical order (as opposed to large blocks of individual monomers) and has a molecular weight of 20,000 g / mol to 1,000,000 g / mol (preferably 40,000 g / mol or 100,000 g / mol to 1,000,000 g / mol). Preferably, the copolymer is linear.

[0020] In a specific composition suitable for the application / embodiment described below for the membrane selective layer, the CZAC comprises about 30 to 80 wt% of a hydrophobic monomer, 1 to 40 wt% of a charged monomer, and 1 to 40 wt% of an amphoteric monomer. A wider range of compositions may be useful for other applications.

[0021] Exemplary monomers for forming each type of repeating unit are listed below.

[0022] Amphoteric ions: sulfobetaine methacrylate (SBMA)*; methacryloxy phosphoryl choline (MPC); carboxybetaine methacrylate (CBMA); sulfobetaine-2-vinylpyridine; sulfobetaine-4-vinylpyridine; sulfobetaine-vinylimidazole; and some other monomers comprising a sulfobetaine, carboxybetaine, or phosphorylcholine moiety.

[0023] Charge / Ionization: Methacryl acid (MAA)*; acrylic acid; styrene sulfonic acid; carboxylic acid, sulfonate, phosphate, or other methacrylate, acrylate, acrylamide, or styrene derivative containing an ionizing / charged group.

[0024] Relative hydrophobicity: 2,2-trifluoroethyl methacrylate (TFEMA)*; other fluorinated acrylates, methacrylates, and acrylamides (e.g., pentafluoropropyl methacrylate, heptafluorobutyl methacrylate, pentafluorophenyl methacrylate); styrene; methyl methacrylate; acrylonitrile; other monomers meeting the above criteria.

[0025] The usefulness of polymer materials has been discussed below, particularly in the context of their use as selective membrane layers. However, polymer materials may be potentially useful in other applications (e.g., additives and compounds in membrane manufacturing).

[0026] CZAC can be coated onto a porous support by methods understood in the membrane industry (e.g., blade coating, non-solvent induced phase separation (NIPS), spray coating). This forms a thin film composite (TFC) membrane comprising at least two layers: a porous support having large pores that provides mechanical integrity; and a thin layer of CZAC that can serve as a "selective layer" of the membrane (thickness preferably less than 10 μm, more preferably less than 3 μm or less than 1 μm). In the present embodiment, the CZAC layer typically contains a continuous dense layer of CZAC (i.e., not ordinary "through-pores" that provide a path for water permeation, except for occasional defects that may appear during processing even if undesirable); in other words, water must permeate through the CZAC, which is the primary transport mechanism, rather than through the pores / holes.

[0027] The generated membranes exhibit size-based separation of neutral organic molecules, showing a higher removal rate for charged solutes than for neutral solutes. This characteristic is useful in some applications where size-based separation is insufficient. For example, when complete or partial removal of contaminants is desired, the combination of size-based and charge-based removal provided by these membranes can improve the quality of the effluent. Alternatively, these membranes can separate two different organic solutes (e.g., amino acids, drug compounds) from each other based on the presence of charged groups.

[0028] This membrane can be modified and adjusted to approach a slightly larger pore size to increase salt removal rates for reverse osmosis (RO) / desalination processes and engineered osmosis (EO) or to have a charge-selective tight ultrafiltration (UF) membrane.

[0029] Commercial NF and RO / EO membranes almost always feature a cross-linked polyamide selective layer. These membranes suffer from two major problems: first, they are prone to fouling and require several pretreatment processes that affect the cost and energy efficiency of the entire desalination process. Second, the membranes are highly sensitive to chlorine, which reacts with the selective layer. Chlorination is typically used to kill microorganisms in the water entering desalination plants to prevent microbial biofouling. Due to the chlorine sensitivity of commercial NF and RO membranes, water is dechlorinated before being fed into the NF or RO unit and then treated with chlorine again before being sent to the customer.

[0030] This membrane avoids both of these problems: amphoteric groups are known and proven to be highly resistant to contamination. The membrane has been shown to be highly resistant to contamination by organic streams. Furthermore, the constituent polymer is not inherently susceptible to attack by chlorine. The membrane has been shown to be stable against commercially available chlorine bleach.

[0031] Membranes can undergo pore rearrangement when exposed to high pH buffers. When exposed to high pH buffers, membranes with a small CZAC selective layer experience a slight increase in pore size, leading to a sudden, irreversible, and stable increase in permeability.

[0032] - CZAC from hydrophobic monomer TFEMA, amphoteric monomer SBMA, and ionizing monomer MAA can be synthesized by free radical polymerization in various monomer ratios.

[0033] This copolymer self-assembles to form a network of hydrophilic nanodomains that function as water permeation pathways.

[0034] - The membrane can be coated onto a commercially available large-pore membrane, which is a porous support, to produce a thin-film composite (TFC) membrane.

[0035] - The membrane exhibits permeability (defined as flux / applied pressure difference) similar to commercially available RO and NF membranes. This can be further improved by reducing the coating thickness and changing the polymer composition.

[0036] - The membrane exhibits size-based selectivity between uncharged organic molecules, including vitamin B12 and β-cyclodextrin, with a removal rate of approximately 92%. The removal model indicates an estimated effective pore size of approximately 2 nm. This pore size can be adjusted to lower and higher values ​​through polymer chemistry and other methods (1–5 nm appears to be the available range).

[0037] - The membrane exhibits a much higher removal rate of charged solutes than of uncharged solutes of similar size.

[0038] - The membrane exhibits a significant salt removal rate, including a NaSO4 removal rate of about 95% compared to some NF membranes.

[0039] - The polymer is stable when exposed to chlorine bleach (e.g., at pH 4).

[0040] - The membrane is highly resistant to contamination by oil slag.

[0041] - Upon exposure to a buffer solution with a relatively high pH, ​​the membrane exhibits a one-time increase in permeability accompanied by a slight decrease in removal rate. The new permeability and pore size are stable, and the changes are irreversible. Furthermore, the membrane obtains a switchable permeability in various ionic solutions that can be controlled by the cations present in the solution.

[0042] In one embodiment, a copolymer comprising a plurality of amphoteric monomer units, a plurality of charged / ionized monomer units, and a plurality of hydrophobic monomer units is provided herein.

[0043] In some embodiments, the molecular weight of the copolymer is 20,000 g / mol to 1,000,000 g / mol. In some embodiments, the molecular weight of the copolymer is 40,000 g / mol to 1,000,000 g / mol. In some embodiments, the molecular weight of the copolymer is 100,000 g / mol to 1,000,000 g / mol.

[0044] In some embodiments, the amphoteric monomer unit constitutes 1 to 40 wt% of the copolymer. In some embodiments, the charged / ionized monomer unit constitutes 1 to 40 wt% of the copolymer. In some embodiments, the hydrophobic monomer unit constitutes 30 to 80 wt% of the copolymer.

[0045] In some embodiments, each of the amphoteric monomer units is formed from a monomer comprising a sulfobetaine, carboxybetaine, or phosphorylcholine moiety. In some embodiments, each of the amphoteric monomer units is formed from a monomer selected from the group consisting of sulfobetaine methacrylate (SBMA), methacryloxy phosphoryl choline (MPC), carboxybetaine methacrylate (CBMA), sulfobetaine-2-vinylpyridine, sulfobetaine-4-vinylpyridine, and sulfobetaine-vinylimidazole. In some embodiments, each of the amphoteric monomer units is formed from sulfobetaine methacrylate (SBMA).

[0046] In some embodiments, each of the charged / ionized monomer units is formed from a monomer selected from the group consisting of methacrylates, acrylates, acrylamides, or styrene derivatives, comprising a carboxylic acid, sulfonate, phosphate, or amine moiety. In some embodiments, each of the charged / ionized monomer unit is methacrylic acid (MAA), acrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, styrene sulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, 2-acrylamido-2-methyl-1-propanesulfonic acid, 2-(dimethylamino)ethyl methacrylate, 2-(diethylamino)ethyl methacrylate, 2-aminoethyl methacrylate, [2-(methacryloyloxy)ethyl]trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, 2-(diethylamino)ethyl acrylate, 2-(dimethylamino)ethyl acrylate, 3-(dimethylamino)propyl acrylate, N-acryloyl-L-valine, It is formed from a monomer selected from the group consisting of (3-acrylamidopropyl)trimethylammonium chloride, N-[3-(dimethylamino)propyl]methacrylamide, 2-isopropenianiline, 4-[N-(methylaminoethyl)aminomethyl]styrene and (vinylbenzyl)trimethylammonium chloride. In some embodiments, each of the charged / ionized monomer units is formed from methacrylic acid (MAA).

[0047] In some embodiments, each hydrophobic monomer unit is formed from a monomer selected from the group consisting of styrene, methyl methacrylate, acrylonitrile, fluoroalkyl acrylate, fluoroaryl acrylate, fluoroalkyl methacrylate, fluoroaryl methacrylate, fluoroalkyl acrylamide, and fluoroaryl acrylamide. In some embodiments, each hydrophobic monomer unit is formed from a monomer selected from the group consisting of fluoroalkyl acrylate, fluoroaryl acrylate, fluoroalkyl methacrylate, fluoroaryl methacrylate, fluoroalkyl acrylamide, and fluoroaryl acrylamide. In some embodiments, each hydrophobic monomer unit is formed from a monomer selected from the group consisting of 2,2-trifluoroethyl methacrylate (TFEMA), pentafluoropropyl methacrylate, heptafluorobutyl methacrylate, and pentafluorophenyl methacrylate. In some embodiments, each of the hydrophobic monomer units is formed from 2,2-trifluoroethyl methacrylate (TFEMA).

[0048] In some embodiments, the hydrophobic monomer unit is characterized in that the formed homopolymer has a glass transition temperature higher than room temperature.

[0049] In some embodiments, the copolymer is a random copolymer.

[0050] In some embodiments, the copolymer is a statistical copolymer.

[0051] In some embodiments, the copolymer is a linear copolymer.

[0052] In some embodiments, the copolymer is poly((sulfobetaine methacrylate)-random-(methacrylic acid)-random-(2,2-trifluoroethyl methacrylate)).

[0053] In another aspect, a polymer material comprising a plurality of copolymers is provided herein. In some embodiments, the polymer material is in the form of a thin film.

[0054] In another embodiment, a thin film composite membrane is provided herein, comprising a porous support and a thin film of a polymer material, wherein the pore size of the porous support is larger than the pore size of the thin film of the polymer material.

[0055] In some embodiments, the thin film of the polymer material has a thickness of 1 nm to 10 μm. In some embodiments, the thin film of the polymer material has a thickness of 1 nm to 3 μm. In some embodiments, the thin film of the polymer material has a thickness of 1 nm to 1 μm.

[0056] In some embodiments, the thin film of the polymer material has an effective pore size of 0.1 to 5 nm. In some embodiments, the thin film of the polymer material has an effective pore size of 0.6 to 3 nm. In some embodiments, the thin film of the polymer material has an effective pore size of 0.6 to 2 nm.

[0057] In some embodiments, the thin film composite exhibits resistance to contamination by emulsion agents.

[0058] In some embodiments, the thin film composite is stable when exposed to chlorine bleach (e.g., at pH 4).

[0059] In some embodiments, the thin film composite undergoes an irreversible change in pore size all at once when exposed to a high pH buffer.

[0060] In some embodiments, the thin film composite exhibits size-based selectivity among uncharged organic molecules.

[0061] In some embodiments, the thin film composite removes charged solutes and salts.

[0062] In another embodiment, a size-based selection or exclusion method is provided herein, comprising the step of contacting a solution containing a plurality of uncharged organic molecules of different sizes with a thin film composite disclosed herein.

[0063] In another embodiment, a charge-based selection or exclusion method is provided herein, comprising the step of contacting a solution containing a plurality of salts with a thin film composite disclosed herein.

[0064] Examples

[0065] To enable a more complete understanding of the invention described herein, the following embodiments are described. The embodiments described in this application are provided to illustrate the compounds, compositions, materials, devices, and methods provided herein and should not be interpreted as limiting the scope thereof.

[0066] Example 1. Synthesis of poly(trifluoroethyl methacrylate)-random-poly(sulfobetaine methacrylate)-random-poly(methacrylic acid) (PTFEMA-SBMA-MAA)

[0067] Example 1A: Synthesis of PTFEMA-SBMA-MAA-B1

[0068] In this example, a random / statistical terpolymer of the monomers trifluoroethyl methacrylate (TFEMA), sulfobetaine methacrylate (SBMA), and methacrylic acid (MAA) (the terpolymer composed of these three components is collectively referred to as PTFEMA-SBMA-MAA) was synthesized as follows. First, TFEMA and MAA were purified using a basic alumina column. Then, DMSO (80 mL), purified TFEMA (5.49 g), SBMA (2.61 g), purified MAA (1.11 g), LiCl (0.090 g), and AIBN (11 mg) were added to a 250 mL wide-bottom reaction flask and sealed with a rubber diaphragm. The mixture was then stirred at room temperature for 2 days to dissolve the zwitterionic monomers. Afterward, the flask was sealed with a rubber diaphragm, purged with N2 for 40 minutes, and then placed in a 70 °C oil bath while stirring. After 20 hours, the reaction was terminated by exposure to air and the addition of MEHQ (0.5 g). Then, for precipitation, the viscous polymer solution was poured into an 800 mL mixture of ethanol and hexane (1:1 volume ratio). The polymer was then cut into small pieces and washed with stirring in an 800 mL mixture of ethanol and hexane (1:1 volume ratio) for over 12 hours. This washing cycle was repeated twice. Afterward, the polymer was left to dry under a fume hood for about one week and finally dried in a vacuum oven at 50 °C for over 24 hours. The yield was determined by the weight of the dried polymer and calculated to be 38%. This polymer will be designated as PTFEMA-SBMA-MAA-B1. The composition of the purified polymer is determined through the integration of the following three sets of peaks. 1 H-NMR spectrum Fig. 2 Calculated from: (1) c'', (2) e', (3) c, c'. The composition was calculated as 61.9 wt% TFEMA, 31.7 wt% SBMA, and 6.4 wt% MAA.

[0069] Example 1B: Synthesis of PTFEMA-SBMA-MAA-B2

[0070] In this example, random / statistical terpolymers of TFEMA, SBMA, and MAA were synthesized as follows. First, SBMA (2.80 g) and DMSO (87 mL) were added to a 250 mL wide-bottom reaction flask. The temperature was raised to 70 °C to dissolve the zwitterionic monomers, and then returned to room temperature. During this cooling period, both TFEMA and MAA were purified using a basic alumina column (VWR). Subsequently, purified TFEMA (4.49 mL), purified MAA (1.86 mL), LiCl (0.10 g), and AIBN (9.8 mg) were added to the reaction flask. The flask was then sealed with a rubber diaphragm, purged with N2 for 30 minutes, and then placed in a 70 °C oil bath while stirring. After 20 hours, the reaction was terminated by exposing it to air and adding MEHQ (0.7 g) dissolved in approximately 5 mL of DMSO. Then, for precipitation, the viscous polymer solution was poured into a 900 mL mixture of ethanol and hexane (1:1 volume ratio). The polymer was then cut into small pieces and washed with stirring in a 900 mL mixture of ethanol and hexane (1:1 volume ratio) for over 12 hours. This washing cycle was repeated three times. Afterward, the polymer was left to dry under a fume hood for about one week, and finally dried in a vacuum oven at 50 °C for four days. The yield was determined by the weight of the dried polymer and calculated to be 60%. This polymer will be designated as PTFEMA-SBMA-MAA-B2. The composition of the purified polymer is determined through the integration of the following three sets of peaks. 1 H-NMR spectrum Fig. 3 Calculated from: (1) c'', (2) e', (3) c, c'. The composition was calculated as 52.2 wt% TFEMA, 34.9 wt% SBMA, and 12.9 wt% MAA.

[0071] Example 2 Polymer structure

[0072] Fig. 16 From the data, it can be inferred that the terpolymer has a nearly random monomer sequence. The terpolymer composition was similar to the initial reaction conditions, and the yield was approximately 70%. This contrasts with the block structure generally associated with self-assembling copolymers. Since there are strict kinetic requirements (all six reactivity ratios being 1) for a terpolymer to be truly random, it is possible for the terpolymer to be somewhat graded / divided or in a block state. However, within the field, the term “random” is not strictly applied. Therefore, to best convey the polymer structure to a wide audience, the terpolymer will be referred to as random.

[0073] Example 3 Formation of a thin film composite (TFC) membrane with a PTFEMA-SBMA-MAA terpolymer selective layer

[0074] Example 3A. Formation of a TFC film from PTFEMA-SBMA-MAA-B1

[0075] In this example, the TFC membrane was prepared using the polymer described in Example 1A. First, the copolymer was dissolved in trifluoroethanol (TFE) at a concentration of 0.11 g copolymer / mL TFE. Then, the solution was filtered using a 1 μm glass syringe filter, degassed by heating to 50 °C for 1 hour, and then cooled back to room temperature. Next, the copolymer solution was coated onto a PES ultrafiltration membrane (Trisep UE50) using a Gardco wire winder (wire size 2½, with a 6 μm wet film deposited). After coating, the coated membrane was quickly immersed in a non-solvent bath of isopropyl alcohol (IPA) for 20 minutes, followed by immersion in deionized water. Through this process, a TFC membrane was produced in which the selective layer described in Example 1A is a PTFEMA-SBMA-MAA-B1 terpolymer.

[0076] Example 3B. Formation of a TFC film from PTFEMA-SBMA-MAA-B2

[0077] In this example, the membrane was prepared using the polymer described in Example 1B. First, the copolymer was dissolved in trifluoroethanol (TFE) at a concentration of 0.11 g copolymer / mL TFE. Then, the solution was filtered using a 1.2 μm glass syringe filter, heated to 50 °C for 1 hour to degas, and then cooled to room temperature. Next, the copolymer solution was coated onto a PES ultrafiltration membrane (Trisep UE50) using a Gardco universal blade applicator with a 20 μm gate setting. After coating, the membrane of the polymer solution was allowed to evaporate for 15 seconds. The coated membrane was then immersed in a non-solvent bath of isopropyl alcohol (IPA) for 20 minutes, followed by immersion in deionized water. Through this procedure, a thin film composite (TFC) membrane was produced in which the selective layer described in Example 1B was a PTFEMA-SBMA-MAA-B2 terpolymer.

[0078] Cross-sections of the TFC membranes described in Examples 2A and 2B were observed using a scanning electron microscope (SEM), which allowed for the analysis of the thickness of the selective layer and the morphology of the membrane. To prepare the samples, membrane sections were freeze-fractured and sputter-coated with gold and palladium. SEM images of the membrane cross-sections were obtained using a Phenom G2 pure tabletop SEM at a setting of 5 kV. Fig. 4a , 4b , and 4c SEM images of an uncoated Trisep UE50 film (support film), the TFC film of Example 2A, and the TFC film of Example 2B are shown. The selective layer is observed to be dense, and for each of the two examples, the thickness is observed to be 0.5 to 1 μm.

[0079] Example 4 . Water permeability of PTFEMA-SBMA-MAA TFC membrane

[0080] In this example, the pure water permeability of the membranes described in Examples 2A and 2B was measured and compared with a membrane prepared with PTFEMA-SBMA. To perform the experiment, 10 mL Amicon 8010 stirred cells were used in a dead-end configuration. The membrane sample area was 4.1 cm². 2 The stirring speed was 500 RPM, and the pressure was 30 psi for the PTFEMA-SBMA-MAA-B1 membrane and 50 psi for the PTFEMA-SBMA-MAA-B2 membrane. To measure membrane permeability, an Ohaus Scout Pro balance connected to a computer was used. Synchronized measurement of permeation over time enabled the measurement of membrane flow rates, which in turn allowed for the calculation of membrane permeability. The permeabilities of the PTFEMA-SBMA-MAA-B1 and PTFEMA-SBMA-MAA-B2 membranes were 1.7 L / m², respectively. 2 .h. bar (abbreviated as LMH / bar) and 2.5 LMH / bar ( Table 1 ).

[0081] [Table 1] Water permeability and composition of PTFEMA-SBMA-MAA-B1 and PTFEMA-SBMA-MAA-B2 membranes described in Examples 3A and 3B

[0082]

[0083] Example 5 Neutral solute removal rate by PTFEM-SBMA-MAA TFC membrane

[0084] In this example, various neutral solutes were filtered using the membrane described in Example 3B. The purpose of these experiments was (1) to demonstrate the ability of the membrane described in Example 3B to filter small neutral molecules from a solution and (2) to establish the effective pore size of the membrane described in Example 3B.

[0085] Filtration experiments were performed using 10 mL Amicon 8010 stud cells in a total filtration manner. The membrane sample area was 4.1 cm². 2 The stirring speed was 500 RPM, and the pressure was 50 psi in all experiments. The first 1.5 mL of permeate was discarded, and the next 0.7 mL was collected for permeate concentration measurement. Permeate concentration was measured using Chemical Oxygen Demand (COD) for sugars and UV-vis spectroscopy for dyes.

[0086] Fig. 5b shows the removal rates of neutral sugar and neutral dye molecules. Size selectivity was observed for the tested neutral solutes, and the removal rates of vitamin B12 (1.48 nm hydrated diameter) and β-cyclodextrin (1.54 nm hydrated diameter) are approximately 92% ( Table 2 The effective pore size was calculated to be 1.95 nm by inputting the removal rate data for sugar molecules into the Extended Nernst Planck Equation with steric hindrance boundary conditions.

[0087] [Table 2] Solute types, hydrated diameters, and removal rates of various neutral solutes filtered by the PTFEMA-SBMA-MAA-B2 TFC membrane

[0088]

[0089] Example 6 Salt removal rate by PTFEMA-SBMA-MAA TFC membrane

[0090] In this example, various ionic solutes were filtered using the membrane described in Example 3B. The purpose of these experiments was to (1) demonstrate the ability of the membrane prepared as described in Example 3B to filter salts from a solution and (2) demonstrate the ability of the membrane prepared as described in Example 3B to selectively filter ionic species while allowing neutral solutes of the same size to pass through.

[0091] Filtration experiments were performed using 10 mL Amicon 8010 stud cells in a total filtration manner. The membrane sample area was 4.1 cm². 2 The stirring speed was 500 RPM, and the pressure was 50 psi in all experiments. The first 1.5 mL of permeate was discarded, and the next 0.7 mL was collected for permeate concentration measurement. Permeate concentration was measured using a conductivity meter. The data Table 3 It was shown in.

[0092] Fig. 6a This shows that the PTFEMA-SBMA-MAA-B1 and PTFEMA-SBMA-MAA-B2 membranes have a greater charge solute removal rate than the PTFEMA-SBMA membrane. Since the neutral solute removal rates are equivalent across all three membranes, this result is evidence that MAA confers anion selectivity to the CZAC membrane. The highest removal rate was for Na2SO4, ranging from 93% to 95%. The removal rate for CaSO4 ranged from 40% to 70%, and the removal rate for NaCl ranged from 30% to 60%.

[0093] To test the hypothesis that deprotonated MAA imparts charge selectivity to the membrane, Na2SO4 was filtered at various pH values ​​( Fig. 6b If deprotonated MAA is the source of anion selectivity, the selectivity should disappear under acidic conditions. As expected, we confirmed that R(Na2SO4) decreases as pH decreases, which can be explained by an equilibrium shift from deprotonated MAA to quantized MAA. The loss of selectivity began in earnest only below pH 5.0, suggesting that the effective pKa of MAA is less than approximately 4.0 in our system (pKa was adjusted to 3.72 using the Donnan Steric Pore Model coupled with the Henderson-Hasselbach equation; see references).

[0094] An effective pKa of less than 4.0 is much lower than the pKa of 4.78 reported for MAA monomers. This means that MAA is about 10 times more reactive when incorporated into CZAC nanostructures than when in free solution. This was contrary to expectations, as confinement is generally known to reduce the reactivity of MAA.

[0095] Fig. 6c shows the removal rate of charged solutes. First, Fig. 6c The PTFEMA-SBMA-MAA-B2 membrane demonstrates the following two notable performance features: (1) a removal rate of 96% for both 1 mM (142 ppm) Na2SO4 and 1 mM (110 ppm) Li2SO4 solutions; (2) a removal rate of 93% for both 5 mM (710 ppm) Na2SO4 and 5 mM (550 ppm) Li2SO4 solutions ( Table 3 The removal rates of CaSO4 and MgSO4 ranged from 40 to 70%, while those of NaCl and LiCl ranged from 30 to 60%. As the feed concentration increased, the solute removal rate decreased, which is consistent with Donan exclusion. The removal rates of various salt types were understood by inputting the removal rate data into the Donan stereopore model (a transport model describing how a combination of hindered transport, stereoexclusion, and Donan equilibrium determines the solute removal rate by a charged membrane). The ability of a membrane to filter ionic species while allowing neutral solutes of the same size to pass through is defined as... Fig. 5 and Fig. 6c This can be determined by comparing. Small ionic species (the hydrated diameter of the sulfate is 0.46 nm, and the hydrodynamic diameter of all ions used in the study is less than 0.7 nm) are removed by the membrane, whereas neutral solutes with a hydrated diameter of less than 1.0 to 1.5 nm are removed minimally. [Table 3] Concentrations and removal rates of various salts by the PTFEMA-SBMA-MAA-B2 membrane described in Example 3B

[0096]

[0097] Example 7 . PTFEMA- r - Dye and Na produced by PTFEMA-SBMA-MAA TFC membranes compared with SBMA TFC membranes 2 SO 4 removal rate of

[0098] In this example, the removal rate of dye and Na2SO4 by the TFC membrane prepared in Example 3A was determined, and PTFEMA- r It was compared with the SBMA TFC membrane (referred to as PTFEMA-SBMA). The synthesis of PTFEMA-SBMA and the fabrication of the PTFEMA-SBMA TFC membrane can be found elsewhere. Here, it is noted that the main difference between the PTFEMA-SBMA membrane and the PTFEMA-SBMA-MAA membrane is that the removal rate of charged solutes is lower in the PTFEMA-SBMA membrane because it lacks MAA. The purpose of these experiments was to (1) demonstrate the ability of the PTFEMA-SBMA-MAA-B1 membrane to filter dyes from solution and its features that may be useful for applications such as dye removal in the textile industry, and (2) further demonstrate the charge selectivity observed in the PTFEMA-SBMA-MAA TFC membrane, which can be used as a suitable control.

[0099] Filtration experiments were performed using 10 mL Amicon 8010 stud cells in a total filtration manner. The membrane sample area was 4.1 cm². 2 The stirring speed was 500 RPM, and the pressure was 27 psi in all experiments. The first 1.8 mL of permeate was discarded, and the next 0.7 mL was collected to measure permeate concentration. Permeate concentration was measured using UV-vis spectroscopy for the dye and conductivity for Na2SO4. The diameter of the dye molecule is V, the volume of the sphere in which the dye molecule is located. molar It was obtained by assuming that, and here V molaris the molar volume of the dye molecule, and the molar volume of the dye was obtained using ChemSW's Molecular Modeling Pro software.

[0100] Fig. 7a and Fig. 7b It shows the removal rates of various dyes and Na2SO4. Table 4 Figures represent the solute removal rates, abbreviations, calculated diameters, and charges by the PTFEMA-SBMA-MAA-B1 membrane and the PTFEMA-SBMA membrane. The removal rates of neutral dyes are similar in the PTFEMA-SBMA-MAA-B1 membrane and the PTFEMA-SBMA membrane, indicating similar effective pore sizes. In contrast, the removal rate of anionic solutes by the PTFEMA-SBMA-MAA-B1 membrane is greater than that of the PTFEMA-SBMA membrane. This provides evidence that membranes prepared from CZAC achieve a greater exclusion rate of charged solutes than membranes prepared from copolymers of only amphoteric and hydrophobic monomers. Furthermore, the exclusion rate of the charged solutes can be explained by the presence of MAA in the PTFEMA-SBMA-MAA-B1 copolymer. MAA, a weak acid, acquires a negative charge upon deprotonation in an aqueous solution. When MAA is incorporated into the zwitterionic domain of a self-assembled PTFEMA-SBMA-MAA-B1 selective layer, it can impart a negative charge to the nanochannels of the membrane. This increases the removal rate of ionic species through a well-proven phenomenon known as gan-an exclusion.

[0101] [Table 4] The TFC membrane and PTFEMA- described in Example 2A r - Solute removal rate by SBMA TFC membrane, abbreviation, calculated diameter, and charge

[0102]

[0103] Example 8 . Antifouling properties of PTFEMA-SBMA-MAA TFC membranes

[0104] Zodiac ions are one of the most powerful antifouling materials currently known. This is because surface adsorption events of fouling contaminants are limited by the strong hydration shell surrounding the zodiac ions (according to simulations, ΔG 수화 (is approximately -500 kJ / mol). Previous studies have shown that membranes composed of random zwitterionic copolymers exhibit excellent antifouling properties, demonstrating that zwitterionics can still act as antifouling agents even within the limitations of membrane nanostructures. To test whether this rule extends to CZAC membranes, total filtration was performed using different model contaminants. A commercially available NF membrane was used as a reference. The membrane was contaminated for 24 hours, and the initial permeate of the CZAC membrane was matched to the reference.

[0105] In this example, the antifouling properties of the PTFEMA-SBMA-MAA-B2 membrane described in Example 3B were measured using an oil-in-water emulsion. The purpose of this was to demonstrate that the membrane possesses antifouling properties, which are an essential feature for any membrane against contaminated feedstocks.

[0106] Filtration experiments were performed using 10 mL Amicon 8010 stud cells in a total filtration manner. The membrane sample area was 4.1 cm². 2The stirring speed was 500 RPM, and the pressure was 50 psi in all experiments. To measure membrane permeability over time, we used an Ohaus Scout Pro balance connected to a computer. Synchronized measurement of permeation over time enabled the measurement of membrane flow rate, which in turn allowed for the calculation of membrane permeability. Normalized permeability (permeability divided by the average DIW permeability before immersing the membrane in contaminants) was calculated. An emulsion was prepared by mixing the surfactant, oil, and water together at <maximum> for 5 minutes. The mass ratio of surfactant to oil was 1:9, and the oil concentration in the stabilized emulsion was 1500 mg / L. Span 80 surfactant was used for one experiment, and DC 193 surfactant was used for the other. Fig. 8a and Fig. 8b This shows the two fouling experiments performed above. Both indicate that the PTFEMA-SBMA-MAA-B2 membrane is fouling resistant.

[0107] Fig. 8c This demonstrates the antifouling properties of PTFEMA-SBMA-MAA-B1 against BSA / CaCl2 (1000 ppm and 10 mM, respectively), with NP30 (Microdyne; PES) used as a control. BSA is a common model protein contaminant, and calcium salts were added to enhance its adsorption. PTFEMA-SBMA-MAA-B1 was observed to be significantly less contaminated than NP30 throughout the 24-hour contamination experiment. After simply rinsing the membrane, the permeability of PTFEMA-SBMA-MAA-B1 was fully recovered, demonstrating that the adsorption event is reversible. In contrast, NP30 was irreversibly contaminated.

[0108] Fig. 8dThis shows the antifouling properties of PTFEMA-SBMA-MAA-B2 against acid / alginate (1000 ppm each), with UA60 (Trisep; PA) used as a control. To increase adsorption, the pH was reduced to 4.5 using HCl. PTFEMA-SBMA-MAA-B2 was less contaminated than UA60 throughout the 24-hour contamination experiment. Immediately after a brief rinse, PTFEMA-SBMA-MAA-B1 recovered 93% of its initial permeability, and after 5 hours, the permeability returned to 96% of the initial value. UA60 experienced a greater initial drop (82% recovery immediately after rinsing) and finally reached 93% recovery after 13 hours.

[0110] Example 9 Chlorine resistance of PTFEMA-SBMA-MAA-B1 TFC membrane

[0111] In this embodiment, a PTFEMA-SBMA-MAA-B1 membrane was exposed to a solution containing a chlorinated solution prepared by diluting commercially available Clorox bleach and adjusting its pH to an acidic value to match commercial cleaning procedures. The purpose of this is to demonstrate that the PTFEMA-SBMA-MAA-B1 membrane is chlorine resistant, which would allow the membrane to be cleaned with sodium hypochlorite, a common disinfectant. Polyamide membranes, which are the cornerstone of the NF market, are unstable when exposed to chlorine, which is a significant weakness of this technology.

[0112] To perform the experiment, 10 mL Amicon 8010 stud cells were used for total filtration. The membrane sample area was 4.1 cm². 2The stirring speed was 500 RPM, and the pressure was 50 psi. To measure membrane permeability, an Ohaus Scout Pro balance connected to a computer was used. Synchronized measurement of permeation over time enabled the measurement of membrane flow rate, which in turn allowed for the calculation of membrane permeability. The membrane's deionized water permeability was measured as described above. A chlorinated solution was prepared by diluting commercially available Clorox laundry bleach with deionized water and adjusting its pH to 4 to ensure that the majority of the hypochlorite was hypochlorous acid. The final HClO concentration was estimated to be approximately 15,000 mg / L. The membrane sample was exposed to this solution for 1 to 2 hours. Then, the permeability was measured again.

[0113] Fig. 9 This indicates that the permeability of the membrane does not change when treated with a chlorinated solution, which indicates that the membrane is stable when exposed to chlorine. Fig. 10 This indicates the effect of chlorine treatment on the PTFEMA-SBMA-MAA-B2 binding chemistry. FTIR spectra obtained before and after 16 hours of immersion in a 2,000 ppm sodium hypochlorite solution at pH 4.5 show that the structure remained intact before and after exposure.

[0114] [Table 5] Effect of chlorine treatment on CZAC-2 (PTFEMA-SBMA-MAA-B2) permeability and selectivity. Membrane performance data obtained before and after 16 hours of immersion in 2,000 ppm NaClO solution (pH 4.5).

[0115]

[0116] Example 10 PTFEMA-r-SBMA-r-MAA base rearrangement observed in TFC membranes

[0117] In this example, the irreversible reaction of the PTFEMA-SBMA-MAA-B1 membrane to bases (referred to as base rearrangement) was investigated. The purpose was to demonstrate the unique reaction behavior of the membrane derived from this novel material. Filtration experiments were performed using 10 mL Amicon 8010 stud cells in a total filtration manner. The membrane sample area was 4.1 cm². 2 The stirring speed was 500 RPM, and the pressure was in the range of 30 to 50 psi in all experiments.

[0118] Fig. 11 This shows the base rearrangement of the PTFEMA-SBMA-MAA-B1 membrane in an alkaline buffered system (PBS, pH=7.4). Upon initial exposure to a 10 mM solution of PBS, permeability increased from an initial value of approximately 1.8 LMH / bar to approximately 2.8 LMH / bar. When the membrane was contacted with distilled water (DIW), permeability increased to approximately 5.1 LMH / bar in DIW. After base rearrangement, permeability can switch reversibly and rapidly between 5.1 LMH / bar in DIW and 2.8 LMH / bar in PBS. There is evidence that TFC membranes with a selective layer composed only of hydrophobic monomers and zwitterionic monomers do not exhibit this reaction in PBS. 4

[0119] Fig. 11 In the case of the rearrangement shown in, HPO4 2- It was suspected that the deprotonation of acidic MAA protons by the strongest base among PBS was the driving force. To test this hypothesis, we performed the following experiment. First, we measured the vitamin B12 removal rate, Na2SO4 removal rate, and permeability of the original PTFEMA-SBMA-MAA-B1 membrane. Then, while measuring permeability, we [injected] NaOH through the membrane (aq)(pH 11, 0.1 mM) was filtered. Then, the membrane was switched back to DIW to see if the same irreversible reaction occurred. Afterward, we measured the vitamin B12 removal rate and Na2SO4 removal rate again. Fig. 12a and Fig. 12b It shows the results of this experiment, and NaOH (aq) This indicates that it can actually cause the base rearrangements observed with PBS. In addition, it is noted that no rearrangements were observed with the PTFEMA SBMA membrane. Fig. 13 The removal rate of Vitamin I2 and Na2SO4 is NaOH (aq) It is shown that both decreased after exposure to, but it is noted that the removal rate of vitamin B12 decreased more than that of Na2SO4.

[0120] During the filtration experiments for Examples 2A and 2B, the membrane permeability was continuously measured using a simple mass balance. The results for the filtration experiments capturing 17 different uncharged / charged / dye solutes are Fig. 14 It was shown in (for the list of filter IDs). Table 6 (Reference). The membrane permeability was not affected during and after filtration of these solutes. This further demonstrates that interactions with bases were the underlying cause of rearrangement in the PTFEMA-SBMA-MAA membrane.

[0121] [Table 6] List of filter IDs

[0122]

[0123] We also investigated how the base-rearranged PTFEMA-SBMA-MAA-B1 membrane reacts with basic solutions containing cations other than sodium and potassium (NaOH (aq)(It contains sodium as a cation, and PBS contains sodium and potassium as cations). Since calcium is known to bind to carboxylates, it was assumed that binding interactions could affect membrane permeability. For this experiment, we measured the permeability of a base-rearranged PTFEMA-SBMA-MAA-B1 membrane while supplying a basic (pH=10) solution of CaSO4. Fig. 15 This shows the results, which indicate a long recovery time for DIW permeability. This suggests that the interaction between cations and deprotonated MAA reduces the permeability of the rearranged PTFEMA-SBMA-MAA membrane.

[0124] Cited references

[0125] 1. Asatekin Alexiou, A.; Bengani, P. Zwitterion Containing Membranes. U.S. Application No. 61901624, 2013.

[0126] 2.Bengani, P.; Kou, Y.; Asatekin, A., Zwitterionic copolymer self-assembly for fouling resistant, high flux membranes with size-based small molecule selectivity. Journal of Membrane Science 2015 , 493, 755-765.

[0127] 3. Bengani-Lutz, P.; Asatekin Alexiou, A. Fabrication of filtration membranes. Patent application No. 62 / 416,340 filed in 2016, November 2, 2016.

[0128] 4. Bengani-Lutz, P.; Converse, E.; Cebe, P.; Asatekin, A., Self-Assembling Zwitterionic Copolymers as Membrane Selective Layers with Excellent Fouling Resistance: Effect of Zwitterion Chemistry. ACS Applied Materials & Interfaces 2017 , 9 (24), 20859-20872.

[0129] 5. Bengani-Lutz, P.; Zaf, R. D.; Culfaz-Emecen, P. Z.; Asatekin, A., Extremely fouling resistant zwitterionic copolymer membranes with ~ 1nm pore size for treating municipal, oily and textile wastewater streams. Journal of Membrane Science 2017 , 543 (Supplement C), 184-194.

[0130] 6. Sadeghi, I.; Asatekin, A., Spontaneous Self-Assembly and Micellization of Random Copolymers in Organic Solvents. Macromolecular Chemistry and Physics 2017 , 218 (20), 1700226.

[0131] 7. Sadeghi, I.; Asatekin, A., Membranes with Functionalized Nanopores for Aromaticity-Based Separation of Small Molecules. ACS Applied Materials & Interfaces 2019 , 11 (13), 12854-12862.

[0132] 8. Asatekin Alexiou, A.; Sadeghi, I. Two-layer nanofiltration membranes. 2015년, 2015년 3월 10일, 특허 출원 62 / 131,001호.

[0133] 9. Ji, Y. L.; An, Q. F.; Zhao, Q.; Sun, W. D.; Lee, K. R.; Chen, H. L.; Gao, C. J., Novel composite nanofiltration membranes containing zwitterions with high permeate flux and improved anti-fouling performance. Journal of Membrane Science 2012 , 390, 243-253.

[0134] 10. Petersen, R. J., Composite Reverse Osmosis and Nanofiltration Membranes. Journal of Membrane Science 1993 , 83 (1), 81-150.

[0135] 11. Bengani-Lutz, P. Zwitterionic Copolymer Self-assembly for Fouling Resistant, High Flux Membranes with Small Molecule Selectivity. Ph.D. Thesis, Tufts University, 2017.

Claims

Claim 1 A thin film composite membrane comprising a porous support and a thin film of a polymer material, wherein the pore size of the porous support is larger than the pore size of the thin film of the polymer material; wherein the polymer material comprises a copolymer comprising a plurality of amphoteric monomer units, a plurality of charged / ionized monomer units, and a plurality of hydrophobic monomer units; wherein each of the hydrophobic monomer units is formed from a monomer selected from the group consisting of styrene, methyl methacrylate, acrylonitrile, fluoroalkyl acrylate, fluoroaryl acrylate, fluoroalkyl methacrylate, fluoroaryl methacrylate, fluoroalkyl acrylamide, and fluoroaryl acrylamide; and wherein the copolymer is a linear, statistical, or random copolymer. Claim 2 A thin film composite according to claim 1, wherein the molecular weight of the copolymer is 20,000 g / mol to 1,000,000 g / mol, 40,000 g / mol to 1,000,000 g / mol, or 100,000 g / mol to 1,000,000 g / mol. Claim 3 A thin film composite according to claim 1, wherein the amphoteric monomer unit constitutes 1 to 40 wt% of the copolymer and / or; the charged / ionized monomer unit constitutes 1 to 40 wt% of the copolymer and / or; and the hydrophobic monomer unit constitutes 30 to 80 wt% of the copolymer. Claim 4 A thin film composite according to claim 1, wherein each of the amphoteric monomer units is formed of a monomer comprising a sulfobetaine, carboxybetaine, or phosphorylcholine moiety; each of the amphoteric monomer units is formed of a monomer selected from the group consisting of sulfobetaine methacrylate (SBMA), methacryloxy phosphorylcholine (MPC), carboxybetaine methacrylate (CBMA), sulfobetaine-2-vinylpyridine, sulfobetaine-4-vinylpyridine, and sulfobetaine-vinylimidazole; and each of the amphoteric monomer units is formed of sulfobetaine methacrylate (SBMA). Claim 5 In claim 1, each of the charged / ionized monomer units is formed of a monomer selected from the group consisting of methacrylates, acrylates, acrylamides, or styrene derivatives comprising a carboxylic acid, sulfonate, phosphate, or amine moiety; Each of the above charged / ionized monomer units is methacrylic acid (MAA), acrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, styrene sulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, 2-acrylamido-2-methyl-1-propanesulfonic acid, 2-(dimethylamino)ethyl methacrylate, 2-(diethylamino)ethyl methacrylate, 2-aminoethyl methacrylate, [2-(methacryloyloxy)ethyl]trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, 2-(diethylamino)ethyl acrylate, 2-(dimethylamino)ethyl acrylate, 3-(dimethylamino)propyl acrylate, N-acryloyl-L-valine, A thin film composite formed from a monomer selected from the group consisting of (3-acrylamidopropyl)trimethylammonium chloride, N-[3-(dimethylamino)propyl]methacrylamide, 2-isopropenianiline, 4-[N-(methylaminoethyl)aminomethyl]styrene, and (vinylbenzyl)trimethylammonium chloride; wherein each of the charged / ionized monomer units is formed of methacrylic acid (MAA). Claim 6 A thin film composite according to claim 1, wherein each of the hydrophobic monomer units is formed of a monomer selected from the group consisting of 2,2-trifluoroethyl methacrylate (TFEMA), pentafluoropropyl methacrylate, heptafluorobutyl methacrylate, and pentafluorophenyl methacrylate; and each of the hydrophobic monomer units is formed of 2,2-trifluoroethyl methacrylate (TFEMA). Claim 7 A thin film composite according to claim 1, wherein the hydrophobic monomer unit is characterized in that the formed homopolymer has a glass transition temperature higher than room temperature. Claim 8 A thin film composite according to claim 1, wherein the copolymer is poly((sulfobetaine methacrylate)-random-(methacrylic acid)-random-(2,2-trifluoroethyl methacrylate)). Claim 9 In claim 1, the thin film of the polymer material has a thickness of 1 nm to 10 μm, 1 nm to 3 μm, or 1 nm to 1 μm, forming a thin film composite film. Claim 10 In claim 1, the thin film of the polymer material is a thin film composite film having an effective pore size of 0.1 nm to 5 nm, 0.6 nm to 3 nm, or 0.6 nm to 2 nm. Claim 11 In claim 1, the thin film composite film is a thin film composite film that exhibits resistance to contamination by oil emulsion. Claim 12 In claim 1, the thin film composite is a thin film composite that is stable when exposed to a chlorine bleach (e.g., at pH 4). Claim 13 In claim 1, the thin film composite film undergoes an irreversible change in pore size at once when exposed to a buffer solution with a pH of 7.4 or higher. Claim 14 In claim 1, the thin film composite film is a thin film composite film that exhibits size-based selectivity between uncharged organic molecules. Claim 15 In claim 1, the thin film composite film is a thin film composite film that removes charged solutes and salts. Claim 16 A size-based selection or exclusion method comprising the step of contacting a solution containing multiple uncharged organic molecules of different sizes with a thin film composite of claim 1. Claim 17 A charge-based selection or exclusion method comprising the step of contacting a solution containing a plurality of salts with the thin film composite of claim 1. Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete Claim 24 delete Claim 25 delete Claim 26 delete Claim 27 delete Claim 28 delete Claim 29 delete Claim 30 delete Claim 31 delete Claim 32 delete Claim 33 delete Claim 34 delete Claim 35 delete

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