SEMIPERMEABLE MEMBRANE AND PREPARATION METHOD THEREOF

Abstract

Disclosed is a semipermeable membrane and its preparation method. The semipermeable membrane obtained has a Turing structure. The Turing structure is an ordered pattern composed of microstructures. The existence of the structure enables the semipermeable membrane of this invention to have both high water permeation flux and excellent salt retention performance, which breaks the flux limit value of the semipermeable membrane while ensuring high selective permeability of the membrane. It also has good anti-pollution properties. The preparation method of the invention can be easily integrated into the existing semipermeable membrane production line without further cost input which has far-reaching practical significance and commercial value.

Claims

1-20. (canceled)

21. A method for preparing a semipermeable membrane, comprising the following steps: preparing the semipermeable membrane by an interfacial polymerization of a solution A and a solution B in the presence of a porous substrate; wherein the solution A comprises a compound a and a polar solvent, and the compound a contains amino groups and/or imino groups; the solution B comprises a compound b and a non-polar solvent, and the compound b contains acid halide groups and/or isocyanate groups; a diffusion coefficient D.sub.A of the compound a in the solution A and a diffusion coefficient D.sub.B of the compound b in the solution B satisfy the following condition: D.sub.B/D.sub.A10.

22. The method according to claim 1, further comprises the following steps: S1. coating a surface of the porous substrate with the solution A to form a liquid film on the surface of the porous substrate; S2. bringing the liquid film in step S1 into contact with the solution B, and forming a separation layer by the interfacial polymerization to obtain the semipermeable membrane.

23. The method according to claim 2, wherein in the step S1, a liquid membrane residence time is 10600 s; and/or, in the step S2, a reaction time of the interfacial polymerization is 10600 s.

24. The method according to claim 1, wherein the diffusion coefficient D.sub.A of the compound a in the solution A and the diffusion coefficient D.sub.B of the compound b in the solution B satisfy the following conditions: 10D.sub.B/D.sub.A10.sup.5.

25. The method according to claim 1, wherein the compound a has a molecular formula:
R(NHx)n, wherein 1x2, 2n3, and R comprises one or more from the group consisting of aromatic ring, alicyclic ring, aromatic heterocyclic ring, heterocyclic ring, and carbon chain; wherein the concentration the compound a in the solution A is 0.15.0 (w/v) %.

26. The method according to claim 1, wherein the compound b is a polyisocyanate and/or a third compound containing at least two acid halide groups.

27. The method according to claim 6, wherein the polyisocyanate comprises one or more from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, 1,4-phenylene diisocyanate, isophorone diisocyanate, methylene-bis(4-cyclohexyl isocyanate), naphthalene diisocyanate, 1,4-cyclohexane diisocyanate, xylyl diisocyanate, bis(isocyanatomethyl)-cyclohexane, lysine diisocyanate, dimethyl diphenylmethane diisocyanate, methyl cyclohexyl diisocyanate, polymethylene phenyl isocyanate, and their oligomers thereof; the third compound containing at least two acid halide groups has a molecular formula:
R(COX)n, wherein, 2n4, and X comprises one from the group consisting of halogens, and R comprises at least one or more from the group consisting of aromatic ring, alicyclic ring, heteroaromatic ring, heterocyclic ring, and carbon chain; wherein the compound b comprises at least one or more from the group consisting of 1,3,5-benzenetricarboxylic acid chloride, 1,4-phthaloyl dichloride, 1,3-phthaloyl dichloride, 2,6-pyridine dicarboxylic acid chloride, 2,5-thiophenedicarbonyl dichloride, 2,5-furandicarbonyl dichloride, 4,4-biphenyldicarbonyl chloride, glutaryl chloride, adipoyl chloride, heptanedioyl dichloride, suberoyl chloride, azelaoyl chloride, sebacoyl chloride, cyclohexyl-1,4-dicarbonyl chloride, and 1,3-adamantanedicarbonyl dichloride.

28. The method according to claim 1, wherein the polar solvent comprises at least one or more from the group consisting of water, dimethylformamide, dimethylacetamide, alcohols, ketones, and esters.

29. The method according to claim 1, wherein the non-polar solvent comprises at least one or more from the group consisting of C.sub.6-C.sub.14 isoparaffin mixture cycloalkanes, and aromatic hydrocarbons.

30. The method according to claim 1, the solution A further comprises a first material which reduces the diffusion coefficient D.sub.A of the compound a in the solution A; wherein the first material comprises at least one or more from the group consisting of macromolecules and nanoparticles.

31. The method according to claim 10, wherein at least one of that macromolecule is capable of forming an intermolecular hydrogen bond and/or an intramolecular hydrogen bond to reduce the diffusion coefficient D.sub.A of the compound a in solution A.

32. The method according to claim 10, wherein the concentration of the macromolecules in the solution A is 0.010.05 (w/v) %.

33. The method according to claim 10, wherein the nanoparticles are organic or inorganic substances, and the nanoparticles comprise at least one or more from the group consisting of surface hydroxylated nanotubes, graphene, carbon nitride; surface carboxylated nanotubes, graphene, carbon nitride, surface aminated nanotubes, graphene, and carbon nitride.

34. The method according to claim 1, the solution A further comprises at least one first additive from the group consisting of catalyst, surfactant, zwitterionic compound, acid, and base.

35. The method according to claim 1, the solution B further comprises at least one second additive from the group consisting of cosolvent, complexing agent, and phase transfer agent.

36. A semipermeable membrane, comprising a porous substrate, and a separation layer; wherein the separation layer has an ordered pattern of microstructure; and the microstructure comprises at least one from speckled structure, vesicle-like structure, tubular structure, spotted structure, and ring structure; and the microstructure is a three-dimensional hollow structure.

37. The semipermeable membrane according to claim 16, wherein the semipermeable membrane has a three-dimensional nano-scale turing structure generated in situ, and the three-dimensional nano-scale turing structure is a stationary pattern structure in which the concentration of chemical substances changes periodically according to space and the three-dimensional nano-scale turning structure is formed by system instability due to diffusion.

38. The semipermeable membrane according to claim 16, wherein the semipermeable membrane comprises a porous substrate and a nanoseparation layer, the three-dimensional nano-scale turing structure being located on the nanoseparation layer; wherein the porous substrate has a surface pore diameter ranged from 2 nm to 1,000 nm, and a cutting molecular weight ranged from 2,000 to 200,000 Daltons.

39. The semipermeable membrane according to claim 16, wherein the semipermeable membrane is a polyamide semipermeable membrane obtained by an interfacial polymerization of a compound a and a third compound containing at least two acid halide groups; or the semipermeable membrane is a polyurea semipermeable membrane obtained by the interfacial polymerization of a polyisocyanate and a polyamine.

40. A membrane module, comprising a semipermeable membrane prepared by the method of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0106] FIG. 1 is a comparison of the desalination performance of the membrane material prepared by the present invention with the reported membrane material properties and the theoretical properties of the membrane material. The abscissa of FIG. 1 represents the water permeation Pw (Water Permeability), and the ordinate represents water. The ratio of the permeation amount Pw to the salt permeation amount Ps (Water-salt selectivity, Pw/Ps).

[0107] FIG. 2-1, FIG. 2-2, and FIG. 2-3 are schematic diagrams of common Turing structures.

[0108] FIG. 3 is a schematic diagram of how an activator and an inhibitor react with each other under specific conditions to produce a spatiotemporal fixed structure.

[0109] FIG. 4 is a schematic illustration of the principle of local activation and lateral inhibition resulting in the creation of a Turing structure.

[0110] FIG. 5 is a schematic diagram of the principle of interfacial polymerization for typical membrane synthesis.

[0111] FIG. 6 is a scanning electron microscopy (SEM) image of an insoluble polyamide (PA) membrane (A pore type, B dense type).

[0112] FIG. 7 is a scanning electron microscopy (SEM) image of an insoluble polyamide (PA) membrane (including a substrate layer) (A pore type, B dense type).

[0113] FIG. 8 is a transmission electron micrograph of a polyamide semipermeable membrane of a nanopopular structure according to Example 14 of the present invention.

[0114] FIG. 9 is a transmission electron micrograph of a polyamide semipermeable membrane of a nanobubble structure according to Example 11 of the present invention.

[0115] FIG. 10 is a transmission electron micrograph of a polyamide semipermeable membrane of a nanotubular structure according to Example 12 of the present invention.

[0116] FIG. 11 is a transmission electron micrograph of a polyamide semipermeable membrane of a nanoring structure according to Example 17 of the present invention.

[0117] FIG. 12 is a transmission electron micrograph of a polyamide semipermeable membrane using various Turing structures in accordance with Example 27 of the present invention.

[0118] FIG. 13 is a schematic diagram of the preparation of a polyamide semipermeable membrane using piperazine (PZ) and trimesoyl chloride (TMC) as starting materials.

[0119] FIG. 14 is a graph showing the diffusion coefficient of the present invention (A: a function of water diffusion coefficient and droplet volume fraction (water plus surfactant) in a water-AOT-decane microemulsion, where D0 is in the absence of AOT and decane. Diffusion coefficient of water in the case of alkane B: Nuclear magnetic resonance sequencing of water, AOT and decane).

[0120] FIG. 15 is an AFM topographical view of a Turing PA membrane, wherein the bright yellow and orange regions correspond to the solid state nano-scale Turing structure formed.

[0121] FIG. 16 is an SEM image of a uniform Turing structure (A: low resolution, large field of view; B: high resolution, small field of view).

[0122] FIG. 17 is a scanning electron microscope (SEM) data measurement diagram of the Turing structure size of the membrane surface.

[0123] FIG. 18 is a projected projection view (TEM) of the membrane (top: cross-sectional TEM image; lower; internal features and three-dimensional morphology of the two structures.

[0124] FIG. 19 is a transmission electron microscope (TEM) data measurement diagram of the Turing structure size of the membrane surface.

[0125] FIG. 20 is a schematic illustration of the water permeation site of the Turing structure membrane calibrated by gold nanoparticle (GNP) dynamic filtration experiments.

[0126] FIG. 21 is a schematic diagram of (A) gold nanoparticle static adsorption experiment and (B) TEM image of the sample after the static test (white arrow marks the position of gold nanoparticles).

[0127] FIG. 22 (A) Schematic diagram of a dynamic filtration experiment using gold nanoparticles and (B) TEM image of the sample after the dynamic filtration test.

[0128] FIG. 23 is a schematic diagram showing the relationship between the nanoparticle deposition pattern and the spatial distribution of the Turing structure (the upper right corners of C and D give the gold nanoparticle coverage percentage; E and F are the high-resolution TEM images of the corresponding regions).

[0129] FIG. 24 is a schematic illustration of the surface and cross-sectional morphology of a Turing structure polyamide semipermeable membrane obtained by the present invention, the polyamide semipermeable membrane 10 comprising a polyamide nano-separation layer 11 and a porous substrate 12, a nano-separation layer 11 has a composition of one or more complex structures 25 of nanotubes 21, nanobubbles 22, nanopoplas 23, and nanorings 24.

[0130] FIG. 25 is an SEM image of the interfacial polymerization process and membrane surface of the TS-I membrane.

[0131] FIG. 26 is an SEM image of the interfacial polymerization process and membrane surface of the TS-II membrane.

[0132] FIG. 27 is an ATR-FTIR spectrum of TS-I and TS-II membrane.

[0133] FIG. 28 and FIG. 29 are respectively TS-I membrane and the TS-II membrane of XPS spectra.

[0134] FIG. 30 is a graph showing the elemental composition and contact angle test results of the TS-I membrane, the TS-II membrane, and the conventional polyamide membrane.

[0135] FIG. 31 is an infrared spectrum analysis of a conventional polyamide membrane.

[0136] FIG. 32 is an X-ray spectroscopy (XPS) analysis of a conventional polyamide membrane.

[0137] FIG. 33 is a diffusion coefficient test result. FIG. (A) shows the diffusion coefficient of small molecules in polyvinyl alcohol (PVA) solution as a function of the volume fraction of macromolecules, where D/D0 is the diffusion coefficient of water in the absence of PVA. FIG. (B) is a 2D nuclear magnetic ordering spectrum (DOSY NMR) of water and piperazine (PZ) in a macromolecular solution.

[0138] FIG. 34 is an AFM image of a conventional polyamide membrane (without Turing structure).

[0139] FIG. 35 is an SEM image of a polyamide membrane prepared by adding different PZ contents, [TMC]=8 mM, [PVA]=34 mM. (A) 12 mM, (B) 23 mM, (C) 35 mM, (D) 46 mM.

[0140] FIG. 36 is an SEM image of a polyamide membrane prepared by adding different TMC contents, [PZ]=23 mM, [PVA]=34 mM. (A) 4 mM, (B) 8 mM, (C) 11 mM, (D) 15 mM.

[0141] FIG. 37 is an SEM image of a polyamide membrane prepared by adding different PVA contents, [TMC]=8 mM, [PZ]=23 mM. (A) 0 mM, (B) 12 mM, (C) 23 mM, (D) 34 mM.

[0142] FIG. 38 is a surface zeta potential analysis.

DETAILED DESCRIPTION OF THE INVENTION

[0143] The invention is further illustrated in detail by the following examples and comparative examples, but the invention is not limited to the embodiments described below. First, an evaluation method of the structure and properties of the semipermeable membrane will be described.

[0144] Semipermeable Membrane Structure

[0145] Transmission electron microscopy (TEM) can be used to observe whether the nano-separation layer of the polyamide semipermeable membrane forms a Turing structure. It can also be characterized using a variety of techniques such as scanning electron microscopy (SEM) or atomic force microscopy (AFM).

[0146] Semipermeable Membrane Performance

[0147] The evaluation indicators are water permeation flux and salt rejection. It was measured at a temperature of 25 C. and a salt concentration of 2000 ppm. All tests were performed 30 minutes after the device was run to ensure a stable test process. The semipermeable membrane of the RO type was tested at a pressure of 15.5 bar (225 psi) using an aqueous NaCl solution; for a semipermeable membrane of the NF type, the test pressure was 4.8 bar (70 psi) and tested with an aqueous solution of MgSO4. The conductivity of the permeate and the feed solution were separately measured by a conductivity meter, and the rejection was calculated using the obtained results and a standard curve.

[0148] Water Permeate Flux

[0149] Defined as the volume of a solution that passes through a semipermeable membrane per unit area per unit time. The unit of water permeation flux used in the present invention is (m3 m2.Math.d-1), that is, (solution volume/semipermeable membrane areatest time).

[0150] Salt Retention Rate

[0151] Defined as the percentage of the dissolved mass of the solution after passing through the semipermeable membrane as a percentage of the total amount of the solute in the solution. It is calculated by the formula (1salt concentration in permeate/salt concentration in the feed liquid)100%.

[0152] Anti-Pollution Performance

[0153] First, the water permeation flux and the salt rejection of the semipermeable membrane were measured, and then 100 ppm casein was added to the test solution for the antifouling performance test. The water permeation flux and the salt rejection of the semipermeable membrane were measured again after 6 hours of operation. In the description of the examples, the test results of the semipermeable membrane anti-contamination performance are given as a percentage of the normalized flux decrease. It is calculated by the formula (1water permeation flux at the end/initial water permeation flux)100%.

[0154] Diffusion Coefficient Detection

[0155] Firstly, the diffusion coefficient of micro-nano droplets in the oil phase is determined. The surfactant is used to disperse water into the homogeneous emulsion in the oil phase, and then two-dimensional nuclear magnetic resonance sorting of water and oil is determined by diffusion-order nuclear magnetic resonance spectrometer. The spectrum (2D DOSY NMR) was used to calculate its diffusion coefficient. Macromer, monomer diffusion coefficient measurement: Oita sub-monomer aqueous arranged different concentrations, measuring the two-dimensional NMR spectroscopy sort, and to determine the diffusion coefficient. In particular, the relative error of the diffusion coefficient is 50%.

Example I

[0156] Preparation of TS-I Membrane:

[0157] The TS-I membranes prepared by the interfacial polymerization reaction of a polysulfone porous substrate membrane with the solution A into contact for 5 after removal minutes. After staying in the atmosphere for about 60 s, it was contacted with the B solution for 60 s and then treated at 80C for 10 min to obtain a TS-I membrane. In particular, solution A contains: 2.0 (w/v) % of 1,3-phenylenediamine, 2.0 (w/v) of sodium phosphate, 0.5 (w/v) of 3-aminobenzoic acid, 0.2 (W/V) % of PVA and 0.1 (W/V) % of sodium dodecylbenzenesulfonate, in particular, when the diffusion coefficient DA=1.995310-6 cm2.Math.s-1; solution B contains: 0.1 (w/v) % of 1,3,5-benzenetricarboxylic acid chloride, 0.5 (w/v) % acetone, in particular, the diffusion coefficient DB=7.079510-5 cm2.Math.s-1 at this time; DB/DA=35.48 (see FIG. 14).

Example II

[0158] Preparation of TS-II Membrane:

[0159] The TS-II membranes prepared by the interfacial polymerization reaction of the porous substrate with a solution of the polyimide membrane A contact duration 10 after removal minutes. After staying in the atmosphere for about 60 s, it was contacted with the B solution for 180 s and then treated at 120 C. for 10 min to obtain a TS-II membrane. In particular, solution A contains: 2.0 (w/v) % of 1,3-phenylenediamine, 1.0 (w/v) % of sodium phosphate, and 1.0 (w/v) of L-leucine benzyl ester. P-toluenesulfonic acid, 0.3 (w/v) % polyvinylpyrrolidone and 0.05 (w/v) % cetyltrimethylammonium chloride, in particular, the diffusion coefficient DA=3.858110-7 cm2.Math.s-1; solution B Contains: 0.1 (w/v) % of 1,3-phthaloyl chloride, 0.5 (w/v) % of acetone, 0.2 (w/v) of dimethyl sulfoxide, in particular, the diffusion coefficient at this time DB=3.433410-5 cm2.Math.s-1; DB/DA=88.99 (see FIG. 14).

Comparative Example I

[0160] PA-I membranes prepared by the interfacial polymerization reaction of a polysulfone porous substrate membrane with the solution A into contact for 5 after removal minutes. After staying in the atmosphere for about 60 s, it was contacted with the B solution for 60 s and then treated at 80 C. for 10 min to obtain a PA-I membrane. In particular, solution A contains: 2.0 (w/v) % of 1,3-phenylenediamine, 2.0 (w/v) % of sodium phosphate, in particular, at this time, the diffusion coefficient DA=110-5 cm2/s-1; Solution B contains: 0.1 (w/v) % of 1,3,5-benzenetricarboxylic acid chloride, in particular, the diffusion coefficient DB=110-5 cm2.Math.s-1; DB/DA=1 (see FIG. 38).

Comparative Example II

[0161] PA-II membranes prepared by the interfacial polymerization reaction of the porous substrate with a solution of the polyimide membrane A contact duration 10 after removal minutes. After staying in the atmosphere for about 60 s, it was contacted with the solution B for 180 s and then treated at 120 C. for 10 min to obtain a PA-II membrane. In particular, solution A comprises: 2.0 (w/v) % of 1,3-phenylenediamine, 1.0 (w/v) % of sodium phosphate, in particular, at this time, the diffusion coefficient DA=110-5 cm2.Math.s-1; solution B contains: 0.1 (w/v) % of 1,3-phthaloyl chloride, in particular, the diffusion coefficient DB=110-5 cm2.Math.s-1; DB/DA=1.

[0162] Atomic force microscopy (AFM) measurements showed that the surface of the membrane with a nano-scale spotted structure (TS-I) and the membrane with a striped Turing structure (TS-II) was relatively rough and uneven. Measuring the root mean square roughness (averagerootmeansquareroughnesses), respectively 22 and 32 nm, which is the traditional semiaromatic polyamide membrane having a substantially comparable and uniform smooth surface (FIG. 15 below). The speckle and fringe structures have nearly the same height, while the surface area increase of TS-II is approximately twice that of TS-I, indicating that the continuous fringe structure has a larger surface area relative to the discrete speckle structure. In order to further study the nano-scale Turing structure, the membrane was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM image shows that the two structures are evenly distributed throughout the membrane (FIG. 16A), which is consistent with the AFM measurements. A closer look at the membrane surface (FIG. 16B) reveals that the nano-scale Turing structure usually consists of a close-packed hexagonal array or interconnected labyrinth networks with diameters ranging from 60 to 80 nm (see FIG. 17). TEM analysis not only presents external features on the surface of the membrane but also provides morphological information about the internal features of the structure. Photomicrographs of the projected area (above FIG. 18) and the cross-sectional TEM (bottom of FIG. 18) show that there are two types of voids in the Turing structure ranging from 30 to 40 nm in diameter (FIG. 19). The Turing PA membrane has a thickness of about 20 nm or less and is twice as thin as a conventional semi-aromatic PA membrane. Under three-dimensional conditions, the Turing structure is a bubble or tubular and resembles a Turing pattern in a BZ microemulsion system (Atomic force microscopy, AFM) measurements show that the surfaces of membranes with the nano-scale spotted (TS-I) and striped (TS-II) Turing structures are relatively rough and heterogeneous. The measured average root mean square roughnesses were 22 and 32 nm, The spotted and striped structures have virtually the same height, the surface area increase of TS-II is approximately two times greater than that of TS-I, suggesting that the continuous striped structures have a larger surface area relative to the discrete spotted structures in the scan area. To further investigate the nano-scale Turing structures, The membranes were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The SEM images show that both structures are uniformly distributed throughout the membranes, which is consistent with the corresponding AFM (Atomic Force Microscope)m A closer look at the membrane surfaces reveals that the nano-scale Turing structures generally consist of close-packed hexagonal arrays or interconnected labyrinthine networks, with diameters ranging from 60 to 80 nm. The TEM analyses not only present the external features on the surfaces of the membranes but also provide morphology information on the internal characteristics of the structures. Projected area and cross-sectional TEM micrographs show that there are two types of voids in the Turing structures, with diameters ranging from 30 to 40 nm. The thickness of the Turing-type PA membranes is about 20 nm or less, two times thinner than that of traditional semi-aromatic PA membranes. In three dimensions, the Turing structures are bubble or tube shaped, like Turing patterns in the BZ microemulsion system).

[0163] The inventors evaluated the separation performance of two membranes with nano-scale speckle (TS-I) and streak (TS-II) Turing structures by salt water desalination test and explored the structure-property relationship of these membranes for water purification. The water and salt transmission data show that both membranes exhibit excellent separation performance, exceeding the upper limit of water and salt separation of conventional nanofiltration membranes (FIG. 1). The amount of water permeability and selectivity are high water and salt, with the conventional polymer membrane trade-off behavior. In contrast, a seesaw-like effect, trade-off behavior refers to an amount of high water permeability always leads to lower The selectivity of water and salt, that is, increasing the selectivity of water and salt is often at the expense of water permeation. Under the same test conditions, the tubular structural membrane TS-II exhibited higher water flux and close salt rejection than the bubble structured membrane TS-I. The water flux of the TS-II membrane is as high as 125 L, which is about twice the water flux of the TS-I membrane. This result is consistent with the surface area trend of the membrane, indicating that the Turing structure has a large influence on the water flux. Based on these results, the inventors believe that there must be some specific sites in the Turing structure with relatively high water permeability, and these high permeability sites can impart enhanced water transport properties to the membrane.

[0164] To verify this phenomenon, the inventors used gold nanoparticles (GNPs) as probes in conjunction with a microscope to visually examine the spatial distribution of water permeation sites in the Turing structure membrane (FIG. 20). GNPs are negatively charged under neutral conditions and both membranes exhibit substantially the same surface charge behavior as GNPs. Therefore, in order for deposition to occur (FIG. 22), the repulsive force originating from the nanoparticle-membrane electrostatic interaction must be overcome. TEM micrographs show that the deposition of GNP is unevenly distributed on the surface of the membrane. The surface area of the nanoparticles of the TS-I and TS-II membranes were 6.0% (FIG. 23C) and 12.8% (FIG. 23D), respectively. GNP is deposited in specific regions of the membrane surface and forms clusters such that other regions of the surface are uncovered or have relatively few sparsely distributed GNPs. Most GNPs are deposited around bubbles (FIG. 23E) or tube structures (FIG. 23F), which provides visual evidence substrateing the presence of relatively high water permeability sites in the nano-scale Turing structure.

[0165] The inventors have discovered that a membrane having a nanoturing structure can be obtained by interfacial polymerization when appropriate initial conditions are produced. Microscopic characterization of the Turing structured polyamide membrane revealed that the spatial distribution of the relatively high water permeability sites is consistent with the nano-scale Turing structure. These unusual nanostructures are produced by diffusion-driven instability and have excellent transport properties in terms of water permeability and water-salt selectivity. It demonstrates that Turing structures can be produced by interfacial polymerization when appropriate initial conditions are created. Microscopic characterization of the Turing-structured membranes reveals that the spatial distribution of relatively higher water permeability sites agrees well with the corresponding Turing structures at the nano-scale. These unusual nanostructures, which are generated by diffusion-driven instability, enable outstanding transport properties in both water permeability and water-salt selectivity.

[0166] FIG. 25 is an SEM diagram of the interfacial polymerization process (FIG. 25A) and the membrane surface of the TS-I membrane. The SEM image shows that the TS-I membrane has a cross section of the bubble structure (FIG. 25B), which is consistent with the TEM micrograph (FIG. 18) and has a uniform structure (FIG. 25C). The bubble shape is about 70 nm in diameter (FIG. 25D).

[0167] FIG. 26 is an SEM diagram of the interfacial polymerization process of the TS-II membrane (FIG. 26A) and the membrane surface. The SEM image shows that the TS-II membrane has a tubular structure cross section (FIG. 26B), which is consistent with the TEM micrograph (FIG. 18, FIG. 19), the structure is evenly distributed (FIG. 26C), and the tubular Turing structure is about 70 nm in diameter (FIG. 26D)

[0168] FIG. 27 is an ATR-FTIR spectrum of TS-I and TS-II. The spectra of TS-I and TS-II (FIG. 27A) The broad peak at 3400 cm-1 is the stretching vibration peak of OH and NH and the peak at 1630 cm-1 is related to the amide group.

[0169] FIG. 28, FIG. 29 are XPS spectrums of TS-I and TS-II membranes. The results show that the surface of the membrane contains carbon, nitrogen, and oxygen. The chemical environment of the carbon atoms is obtained by deconvolution of the high-resolution spectrum. Spectrum has two peaks: one is at 284.6 eV (aliphatic/aromatic CH or CC bonds), the other is at 277.6 eV (amide OCN and a carboxyl group OCO group).

Example III Preparation of Polyurea Semipermeable Membrane with Turing Structure

[0170] Polysulfone porous substrate with a solution A into contact for 5 after removal minutes. After staying in the atmosphere for about 60 s, it was contacted with the solution B for 60 s and then treated at 120 C. for 10 min to obtain a polyurea membrane. In particular, solution A contains: 2.0 (w/v) % of 1,3-phenylenediamine, 2.0 (w/v) % of sodium phosphate, 0.3 (w/v) % of PVA, and 0.1 (w/v) % sodium dodecylbenzenesulfonate, in particular, when the diffusion coefficient DA=1.062510-7 cm2.Math.s-1; solution B contains: 0.1 (W/V) % naphthalene diisocyanate, 0.5 (w/v) % acetone, in particular, the diffusion coefficient DB=6.137810-6 cm2.Math.s-1; DB/DA=57.77.

TABLE-US-00001 Anti- Semi- Water Salt pollution permeable permeation rejec- performance membrane flux (m 3/m tion(NaCl, (% flux DB/DA structure 2 .Math. d) %) reduction) Exam- 57.77 Nanobubble 1.06 99.0 21.4 ple

[0171] In the present invention, Examples 1 to 10 (E1-E10) and Comparative Examples 1 to 5 (R1-R5) in Table I are positive/reverse osmosis membranes; Examples 11 to 27 and Comparative Examples 6 to 8 are nanofiltration membranes. Sodium chloride in the following examples is understood to be an equimolar ratio product of hydrochloric acid and sodium hydroxide.

[0172] On a porous substrate, the solution A and solution B interfacial polymerization reaction to obtain the semipermeable membrane; the semipermeable membrane from a solution A and the solution B in the presence of the porous substrate by a reaction of interfacial polymerization prepared; solution The raw material of A is shown in Table I, and the raw material of solution B is shown in Table II. The parameters of each system are shown in Table III, and the mass concentration (w/v) % of the corresponding substance is shown in parentheses:

TABLE-US-00002 TABLE I Diffusion coefficient DA (105 Example Compound a Polar solvent Macromolecule Nanoparticle cm 2/s) E1 1,2-phenylenediamme(0.1) water Agarose 0.021 E2 1,3-phenylenediamme(0.2) 30% ethanol Carboxymethyl 0.10 starch E3 2,4-diaminotolueue(0.5) 20% DMF Carboxymethyl 0.0873 cellulose E4 1,4-xylylenediamine(1.0) 10% isopropanol Polyacrylic 0.0794 acid E5 1,3,5-triaminobenzene(1.0) water Polyacrylamide 0.0689 E6 Ethylenediamine(2.0) 5% acetone Polyethylene 0.0122 glycol E7 1,4-butanediamine(2.5) water Polyethyleneimine 0.0063 E8 Tris (2-aminoethyl)amine 50% ethanol Carbon 0.0027 (3.0) nitride E9 1,3-diaminocyclohexane(4.0) water Surface 0.0002 hydroxylated graphene E10 Piperazine (5.0) water Surface 0.0001 aminated carbon nanotube R1 1,2-phenylenediamine(0.1) water 1.150 R2 1,3-phenylenediamine(0.2) water 1.022 R3 2,4-diaminotolueue(0.5) water 1.072 R4 1,4-xylylenediamine(1.0) Butyl acetate 1.078 R5 1,3,5-triaminobenzene(2.0) water 1.222

TABLE-US-00003 TABLE II Diffusion coefficientDB Non-polar (105 cm Example Compound b solvent Additive 2/s) E1 1,3,5-benzenetricarboxylic IsoPaG Ethylene glycol 1.04 acid chloride (0.05) dimethyl ether(0.02) E2 Toluene diisocyanate (0.10) IsoPaG Ethylene glycol(0.05) 1.00 E3 2,5-di Cyclohexane Acetone (0.1) 1.14 (chloroformyl)thiophene (0.20) E4 Adipyl chloride (0.50) IsoPaG Glycerin (0.05) 1.24 E5 P-phenylene Toluene Ethyl acetate (0.1) 1.10 diisocyanate(0.50) E6 1,3-phthaloyl chloride(0.80) Octane Diglycidyl ether(0.02) 1.22 E7 1,4-cyclohexane Hexane 1,4-dioxane (0.03) 1.48 diisocyanate (1.00) E8 Dimethyldiphenylmethane IsoPaG Tributyl 1.42 diisocyanate (1.20) phosphate(0.05) E9 Polymethylene phenyl IsoPaG + Dimethyl 1.28 isocyanate (1.50) n-hexane sulfoxide(0.02) (50%) E10 1,3-adamantanedioyl IsoPaG N- 1.00 chloride (2.00) methylpyrrolidone(0.2) R1 1,3,5-benzenetricarboxylic IsoPaG Ethylene glycol 1.04 acid chloride (0.05) dimethyl ether(0.05) R2 Toluene diisocyanate (0.10) O-xylene Ethylene glycol(0.02) 1.00 R3 2,5-di IsoPaG Acetone (0.05) 1.14 (chloroformyl)thiophene (0.20) R4 Adipyl chloride (0.50) IsoPaG Glycerin (0.15) 1.24 R5 P-phenylene IsoPaG Ethyl acetate(0.02) 1.10 diisocyanate(0.50)

TABLE-US-00004 TABLE III Anti-pollution Flux performance Exam- Surface (m3/m Intercep- (flux ple DB/DA structure 2 .Math. d) tion rate decreased) E1 50 Tubular 1.48 99.30% 19.20% Turing Structure E2 10.0 Patchy Turing 1.10 99.10% 19.60% Structure E3 13.1 Ring-shaped 1.06 99.41% 18.32% Turing structure E4 15.6 Tubular 1.12 99.15% 18.56% Turing Structure E5 16.0 Tubular 1.45 98.92% 19.21% Turing Structure E6 10 0 Mixed Turing 1.23 99.01% 17.89% structure E7 234.9 Bubble 1.00 98.82% 18.74% structure E8 525.9 Bubble 1.21 98.79% 16.82% structure E9 6400 Bubble 1.36 98.52% 17.13% structure E10 10 0 00 Bubble 1.29 98.12% 17.05% structure R1 0.9 Peak-valley 0.84 99.50% 29.50% structure R2 1.0 Peak-valley 0.77 99.10% 30.20% structure R3 1.1 Peak-valley 0.76 99.45% 30.31% structure R4 1.2 Peak-valley 0.46 97.20% 35.62% structure R5 0.9 No continuous membrane

Example 11

[0173] Will contain 2.0 (w/v) % of 1,3-phenylenediamine, 1.0 (w/v) % sodium phosphate, 0.5 (w/v) % of 3-aminobenzoic acid, 0.2 (w/v) % A polar solution of polyvinylpyrrolidone (average weight average molecular weight of 160,000) and 0.1 (w/v) of sodium dodecylbenzenesulfonate was coated on a polyethersulfone porous substrate and the excess solution was removed after immersion for about 120 seconds. After staying in the atmosphere for about 60 s, a non-polar organic solution containing 0.1 (w/v) % 1,3,5-benzenetricarboxylic acid chloride and 0.5 (w/v) % acetone was contacted with the coating solution. After treatment at 120 C. for 3 min, a polyamide semipermeable membrane having a nanobubble Turing structure was obtained on a polyethersulfone porous substrate.

Comparative Example 6

[0174] A polyamide semipermeable membrane was obtained in the same manner as in Example 11 except that the macromolecular auxiliary was not added to the polar solvent.

TABLE-US-00005 TABLE 1 Anti- Semi- Water pollution permeable permeation Salt performance membrane flux (m 3/m rejection (% flux DB/DA structure 2 .Math. d) (NaCl, %) reduction) Exam- 50 Nano- 1.18 99.3 19.2 ple 11 bubble Compar- 1 Peak- 0.84 99.5 29.5 ative valley Example 6 structure

Example 12

[0175] The polar solution consisted of 3.0 (w/v) % of 1,3-phenylenediamine, 1.0 (w/v) % of sodium chloride, 0.5 (w/v) % of isopropanol, 0.2 (w/v) % polyvinyl alcohol (average weight average molecular weight of 100,000) and 0.1 (W/V) % of cetyl trimethyl ammonium bromide, a non-polar organic solution containing 0.2 (W/V) % of 1,3,5-benzenetricarboxylic acid chloride. The interfacial polymerization process was the same as in Example 11, and a polyamide semipermeable membrane having a nanotubular Turing structure was obtained on a polysulfone porous substrate.

Example 13

[0176] The interfacial polymerization process was the same as in Example 12, in which 1.0 (w/v) % of 2-aminobenzoic acid was added to the polar solvent, and 0.5 (w/v) % of polyvinyl alcohol was used after beat treatment (average weight average Molecular weight 100,000), 0.2 (w/v) % of glutaraldehyde 0.02 (w/v) % hydrochloric acid solution was coated on the polyamide layer, and finally a polyamide having a nanotubular Turing structure was obtained on the polysulfone porous substrate.

Comparative Example 7

[0177] A polyamide semipermeable membrane was obtained in the same manner as in Example 12 except that the macromolecular auxiliary was not added to the polar solvent.

TABLE-US-00006 TABLE 2 Anti- Semi- Water pollution permeable permeation Salt performance membrane flux (m 3/m rejection (% flux DB/DA structure 2, d) (NaCl, %) reduction) Exam- 100 Nano- 1.24 99.5 19.6 ple 12 tubular Exam- 200 Nano- 1.32 99.6 16.7 ple 13 tubular Compar- 1 Peak- 0.91 99.4 30.2 ative valley Example 7 structure

Example 14

[0178] The polar solution composition is 2.0 (w/v) % of 1,3-phenylenediamine, 1.0 (w/v) % of sodium hydroxide, 0.5 (w/v) of 3-aminobenzenesulfonic acid, 0.2 (w/v) % polyethyleneimine (average weight average molecular weight 70,000) and 0.1 (w/v) % sodium diisooctyl sulfosuccinate, non-polar solution containing 0.1 (w/v) % of 1,3,5-benzenetricarboxylic acid chloride and 0.5 (w/v) % ethyl acetate. The interfacial polymerization process was the same as in Example 11, and a polyamide semipermeable membrane having a nanopatular Turing structure was obtained on a polyamide-imide porous substrate.

Example 15

[0179] The interfacial polymerization process was the same as in Example 14, except that 0.1 (w/v) % polyethyleneimine (average weight average molecular weight 70,000) and 0.1 (w/v) % polyvinylpyrrolidone were added to the polar solution (average A weight average molecular weight of 160,000 is used as a macromolecular additive to obtain a polyamide semipermeable membrane having a nanopatular Turing structure on a polyethersulfone porous substrate.

Example 16

[0180] The interfacial polymerization process was the same as in Example 14. 0.2 (w/v) % polyvinyl alcohol (average weight average molecular weight 100,000) was added as a macromolecular additive to the polar solution, and 0.5 (w/v) % (3-carboxypropyl) trimethylammonium chloride was used as an auxiliary to finally obtain a polyamide semipermeable membrane having a nanopatular Turing structure on a polyethersulfone substrate.

TABLE-US-00007 TABLE 3 Anti- Semi- Water pollution permeable permeation Salt performance membrane flux (m3/ rejection (% flux DB/DA structure m2d) (NaCl, %) reduction) Exam- 600 Nano plaque 1.08 99.4 20.6 ple 14 Exam- 647 Nano plaque 1.10 99.1 18.7 ple 15 Exam- 663 Nano plaque 1.01 99.2 19.5 ple 16

Example 17

[0181] The polar solution consisted of 3.0 (w/v) % of 1,3-phenylenediamine, 1.0 (w/v) % of sodium carbonate, 0.5 (w/v) of dimethyl sulfoxide, and 0.2 (w/v) % polyethylene glycol (average weight average molecular weight of 100,000) and 0.1 (W/V) % of polyethylene glycol octylphenyl ether, non-polar solution contains (W/V) 0.2% of 1,3,5-Benzene tricarboxylic acid chloride. The interfacial polymerization process was the same as in Example 11, and a polyamide semipermeable membrane having a nanocyclic Turing structure was obtained on a polysulfone porous substrate.

Example 18

[0182] The composition of the solution was the same as in Example 17, except that the polyfunctional amine solution was removed after being immersed for about 60 s, and was allowed to contact with a non-polar organic solvent containing a polyfunctional acid halide after standing at room temperature for 60 s. After completion of the reaction, the mixture was treated at 100 C. for 5 min to obtain a polyamide semipermeable membrane having a nano ring-shaped Turing structure on a polyvinylidene fluoride porous substrate.

TABLE-US-00008 TABLE 4 Anti- Semi- Water pollution permeable permeation Salt performance membrane flux (m3/ rejection (% flux DB/DA structure m2d) (NaCl, %) reduction) Exam- 127 Nanoring 1.03 99.3 18.5 ple 17 Exam- 203 Nanoring 1.15 99.0 19.1 ple 18

Example 19

[0183] The process of interfacial polymerization was the same as in Example 18 except that 1.0 (w/v) % of sodium phosphate was added as an acid absorbent, 0.2 (w/v) % of polyvinylpyrrolidone (average weight average molecular weight). 160,000) as a macromolecular additive.

Example 20

[0184] The process of interfacial polymerization was the same as in Example 19, and the post-treatment process was the same as in Example 13, and a polyamide semipermeable membrane having various Turing structures was obtained on a polysulfone porous substrate.

TABLE-US-00009 TABLE 5 Anti- Semi- Water pollution permeable permeation Salt performance membrane flux (m3/ rejection (% flux DB/DA structure m2d) (NaCl, %) reduction) Exam- 468 Multiple 1.01 99.0 20.3 ple 19 structures Exam- 500 Multiple 1.08 99.3 16.1 ple 20 structures

Example 21

[0185] It will contain 0.3 (w/v) % piperazine, 1.0 (w/v) % sodium phosphate, 0.2 (w/v) % polyvinylpyrrolidone (average weight average molecular weight 160,000) and 0.1 (w/v) % A polar solution of sodium dodecylbenzene sulfonate was applied to the polysulfone porous substrate and the excess solution was removed after about 2 min of immersion. A non-polar solution containing 0.2 (w/v) % 1,3,5-benzenetricarboxylic acid chloride and 0.5 (w/v) % acetone was then contacted with the coating solution. After completion of the reaction, the mixture was treated at 90 C. for 6 min to obtain a polyamide semipermeable membrane having a nanobubble Turing structure on a polysulfone porous substrate.

TABLE-US-00010 TABLE 6 Anti- Semi- Water Salt pollution permeable permeation rejection performance membrane flux (m3/ (MgSO4 (% flux DB/DA structure m2d) %) reduction) Exam- 8000 Nano- 1.36 98.6 15.4 ple 21 bubble

[0186] The polar solution consisted of 0.2 (w/v) % piperazine, 1.0 (w/v) % sodium chloride, 0.5 (w/v) % isopropanol, 0.2 (w/v) % polyethylene. The alcohol (average weight average molecular weight 100,000) and 0.1 (w/v) % of cetyltrimethylammonium bromide were removed after being immersed on the polysulfone porous substrate for about 60 s. After staying for 60 s at room temperature, it was contacted with a non-polar solution containing 0.2 (w/v) % of 1,3,5-benzenetricarboxylic acid chloride. After the reaction was completed, it was treated at 80 C. for 12 min to obtain a polyamide semipermeable membrane having a nanobubble and a nanotubular Turing structure.

Comparative Example 3

[0187] A polyamide semipermeable membrane was obtained in the same manner as in Example 22 except that the macromolecular auxiliary was not added.

TABLE-US-00011 TABLE 7 Anti- Semi- Water Salt pollution permeable permeation rejection performance membrane flux (m3/ (MgSO4 (% flux DB/DA structure m2d) %) reduction) Exam- 511 Two 2.20 99.2 12.8 ple 22 structures Compar- 1 Smooth 0.55 98.0 19.1 ative and flat Example 8

Example 23

[0188] The polar solution was 0.2 (w/v) % piperazine, 1.0 (w/v) % sodium hydroxide, 0.2 (w/v) % polyethyleneimine (average weight average molecular weight 70,000) and 0.1 (w/v) % sodium diisooctyl sulfosuccinate, a non-polar solution of 0.3 (w/v) % 1,3,5-benzenetricarboxylic acid chloride and 0.5 (w/v) % ethyl acetate. The interfacial polymerization process was the same as in Example 21, and a polyamide semipermeable membrane having a nanopatular Turing structure was obtained on a polyethersulfone porous substrate.

Example 24

[0189] The solution composition and the interfacial polymerization process were the same as in Example 23, except that the interfacial polymerization reaction was carried out on a polyvinylidene fluoride porous substrate to obtain a polyamide semipermeable membrane having a nanopatular Turing structure.

TABLE-US-00012 TABLE 8 Anti- Semi- Water Salt pollution permeable permeation rejection performance membrane flux (m3/ (MgSO4, (% flux DB/DA structure m2d) %) reduction) Exam- 311 Nano 1.23 98.2 15.8 ple 23 plaque Exam- 296 Nano 1.35 98.0 14.6 ple 24 plaque

Example 25

[0190] The polar solution consists of 0.3 (w/v) % piperazine, 1.0 (w/v) % sodium carbonate, 0.5 (w/v) % dimethyl sulfoxide, 0.2 (w/v) % polyethylene. Alcohol (average weight average molecular weight 100,000) and 0.1 (w/v) % of polyethylene glycol octylphenyl ether, and the non-polar solution was 0.3 (w/v) % of 1,3,5-benzenetricarboxylic acid chloride. The interfacial polymerization process was the same as in Example 22, and a polyamide semipermeable membrane having a nanocyclic Turing structure was obtained on a polyamide-imide porous substrate.

Example 26

[0191] The solution composition and interfacial polymerization process were the same as in Example 25, except that after heat treatment, glutaraldehyde containing 0.5 (w/v) % polyvinyl alcohol (average weight average molecular weight 100,000), 0.2 (w/v) %, 0.1 (w/v) % diglycidyl ether and 0.01 (w/v) % sulfuric acid solution were coated on the polyamide layer, and a polyamide half having a nano ring-shaped Turing structure was obtained on the polyethersulfone porous substrate.

TABLE-US-00013 TABLE 9 Anti- Semi- Water Salt pollution permeable permeation rejection performance membrane flux (m3/ (MgSO4 (% flux DB/DA structure m2d) %) reduction) Exam- 628 Nanoring 1.32 98.5 15.1 ple 25 Exam- 663 Nanoring 1.48 98.8 13.2 ple 26

Example 27

[0192] The solution composition and interfacial polymerization process were the same as in Example 25, except that 0.5 (w/v) % acetone was used instead of dimethyl sulfoxide, and 0.2 (w/v) % polyvinylpyrrolidone (average weight average molecular weight 160,000) was used. Instead of polyethylene glycol. A polyamide semipermeable membrane having a plurality of Turing structures was obtained on a polysulfone porous substrate.

TABLE-US-00014 TABLE 10 Anti- Semi- Water Salt pollution permeable permeation rejection performance membrane flux (m3/ (MgSO4, (% flux DB/DA structure m2d) %) reduction) Exam- 507 Multiple 1.21 98.1 18.4 ple 27 structures

[0193] As shown in Tables 1 to 10, under the same test conditions, the Turing structure polyamide semipermeable membrane produced by the technique disclosed in the present invention has higher water permeation than the semipermeable membrane manufactured by the conventional technique. Flux and retention of salt. When there is a proteinaceous contaminant in the raw material liquid, the Turing-type polyamide semipermeable membrane has less water permeation flux attenuation, and its anti-pollution performance is superior to that of the polyamide semipermeable membrane manufactured by the conventional method.

[0194] As shown in the above examples and comparative examples, the polyamide semipermeable membrane produced by the technique disclosed in the present invention has a Turing structure and can simultaneously have high water permeation flux, high salt rejection and anti-pollution performance.

[0195] FIG. 8-FIG. 12, respectively Example 14, 11, 12, 17 and 27 of the semipermeable membrane corresponding TEM in FIG. As can be seen from FIG. 9, the polyamide semipermeable membrane has a nanobubble structure. As can be seen from FIG. 10, the polyamide semipermeable membrane has a nanotubular structure. As can be seen from FIG. 8, the polyamide semipermeable membrane has a nanopopular structure. As can be seen from FIG. 11, the polyamide semipermeable membrane has a nanoring structure. As can be seen from FIG. 12, the polyamide semipermeable membrane has a plurality of Turing structures.

[0196] In the various embodiments given herein, the features described as preferred or in some embodiments or preferably are not to be construed as being required, essential or critical to the invention.