KR101823050B1 - Porous support for water treatment membrane, thin-film composite membrane containing the same and preparation method thereof - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a porous support for a water treatment separation membrane, an ultra-thin composite membrane including the same, and a method for producing the same, which comprises forming a porous support using a sulfonated poly (arylene ether sulfone) copolymer having a crosslinked structure, The present invention relates to a technique for manufacturing a composite membrane including an active layer and applying it to a water treatment separation membrane.
The sulfonated poly (arylene ether sulfone) copolymer support having a thin and high porosity structure produced according to the present invention and the ultra-thin composite membrane comprising the same have excellent thermal and chemical stability and mechanical properties, However, since the internal concentration polarization can be minimized, a high water permeability and a high power density can be obtained. Therefore, the present invention can be applied to a water treatment membrane including a pressure delay osmosis process or a positive osmosis process.

Description

TECHNICAL FIELD [0001] The present invention relates to a porous support for a water treatment separation membrane, an ultra-thin composite membrane including the same, and a method for manufacturing the same.

The present invention relates to a porous support for a water treatment separator, an ultra-thin composite membrane comprising the same, and a method of manufacturing the same. More particularly, the present invention relates to a porous support for a water treatment separator, which comprises a porous support formed of a sulfonated poly (arylene ether sulfone) The present invention relates to a technique for preparing a composite membrane including an active layer of a thin film on a support and applying the membrane to a water treatment membrane.

Recently, it has been pointed out that the desalination process using a reverse osmosis membrane as a water treatment separator has a high energy consumption industrially. Therefore, it is required to develop a water treatment membrane for power or water production based on a new driving force. Particularly, salinity power generation using osmotic pressure for power production has attracted attention, and studies on pressure retarded osmosis process have been actively carried out. The pressure-delayed osmosis process is a process in which the osmotic pressure difference of two solutions having a difference in salinity is used as a driving force to apply a pressure lower than the osmotic pressure to the opposite direction of the osmotic phenomenon through the separation membrane to delay water flow in the osmotic direction, It is a way to produce electricity. On the other hand, since the osmosis process, which can replace the reverse osmosis process for the purpose of producing water, uses the osmotic phenomenon as the driving force in the same way as the pressure delay osmosis process, the separation membrane for the osmosis process The research on the study is also going on steadily.

As the separation membrane for the pressure delay osmosis process, a flat membrane or a hollow fiber membrane is a mainstream. Generally, a porous support of polysulfone (PS) or polyethylene terephthalate (PET) based on 100 to 200 탆 thickness and a polyamide PA) -based thin-film active layer (Patent Document 1).

However, in the conventional pressure-delayed osmosis membrane, when the water is permeated through the membrane, the concentration of the salt in the inlet solution is increased by increasing the salinity concentration at the interface between the active layer and the support, As a result, the density difference, which is the driving force of water permeation, is reduced. As a result, the water permeability is lowered and the power density is lowered. Ultimately, the thickness of the support is as large as 100 to 200 탆, The same phenomenon frequently occurs in the membrane for the positive osmosis process. In addition, the separator used in the pressure-delayed osmosis process or the osmosis process should be able to withstand high operating pressures, so that its mechanical properties, including thermal and chemical stability, should be excellent.

On the other hand, a sulfonated polyether ether ketone copolymer in which polyether ether ketone (PEEK) is sulfonated as a polyarylene ether-based copolymer material having excellent thermal and chemical stability and mechanical properties is widely used as a material for a separator And a method of manufacturing the same in the form of an electrospray membrane or a flat membrane. However, most of them are applied to a polymer electrolyte membrane of a fuel cell, and application of a water treatment membrane including a pressure delayed osmosis process or a positive osmosis process is known (Patent Document 2, Non-Patent Document 1).

Therefore, the inventors of the present invention have conducted extensive studies to expand the application field of a polyarylene ether copolymer film having excellent thermal and chemical stability and mechanical properties. As a result, they have found that sulfonated polyarylsulfonated polyarylene ether sulfone copolymers When a porous support in the form of an electrodeposition film having a crosslinking structure is formed from a phenylene sulfone copolymer and a thin active layer is formed on the porous support to prepare an ultra-thin composite membrane, a wide range The present invention has been completed based on the fact that it can be applied as a separator of a water treatment process.

Patent Document 1 Korean Patent Publication No. 10-1391654 Patent Document 2: Korean Patent Publication No. 10-1292214

Non-Patent Document 1 M. Luisa Di Vona et al., J. Phys. Chem. B 113, 7505-7512 (2009)

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a polymer electrolyte membrane which is excellent in thermal and chemical stability and mechanical properties and can withstand high operating pressure, Thin porous membrane for a water treatment separation membrane having a high porosity, which can obtain a high power density according to the present invention, and a method for manufacturing the same.

In order to accomplish the above object, the present invention provides a porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure for a water treatment separator having a repeating unit represented by the following formula (1).

≪ Formula 1 >

(Wherein Q is a single bond or O, S, C (= O), C (= O) NH, Si (CH ₃ ) ₂ , (CH ₂ ) _{p CF 2) q (1≤q≤10),} C (CH 3) 2, C (CF 3) 2, or _{C (CH 3) (CF 3} ) , n is 0, as a repeating unit, the molar ratio of structural unit I < n < 1)

The porous sulfonated polyarylene ether sulfone copolymer support having the crosslinked structure is characterized by being an electrospun film.

The electrodisplacive film has a thickness of 20 to 50 탆 and a porosity of 60 to 80%.

And the water treatment separation membrane is a separation membrane for a pressure delayed osmosis process.

Wherein the water treatment separation membrane is a separation membrane for a positive osmosis process.

The present invention also relates to a porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure having a repeating unit represented by the above formula (1); And an active layer of a thin film formed on the porous support.

Wherein the active layer of the thin film is an aromatic polyamide having a crosslinked structure having a repeating unit represented by the following formula (2).

(2)

The active layer of the thin film has a thickness of 50 to 300 nm.

In addition, the present invention relates to a process for the production of a photopolymerizable composition, comprising the steps of: I) mixing 4,4'-dichlorodiphenylsulfone or 4,4'-difluorodiphenylsulfone, 4,4'-biphenol compound and sulfonated 4,4'- Sulfone or sulfonated 4,4'-difluorodiphenylsulfone to synthesize a sulfonated polyarylene ether sulfone copolymer;

II) forming a polymer solution by dissolving the synthesized sulfonated polyarylene ether sulfone copolymer in an organic solvent by a conventional electrospinning method; And

III) thermally cross-linking the membrane obtained in the step II), wherein the porous sulfonated polyarylene ether sulfone copolymer support has a repeating unit represented by the general formula (1). do.

The 4,4'-biphenol compound is characterized by being represented by the following formula (II).

&Lt;

(In the above formula (II), Q is the same as defined in the above formula (1)

The thermal crosslinking in the step (III) is performed by heat-treating in a steam atmosphere of dimethylsulfoxide at 180 to 250 ° C for 1 to 12 hours.

In addition, the present invention relates to a method for producing an aromatic polyamide thin film having a crosslinked structure having a repeating unit represented by the above formula (2) on a porous sulfonated polyarylene ether sulfone copolymer support having a repeating unit represented by the above formula (1) The present invention also provides a method for producing an ultra-thin composite membrane for water treatment.

The active layer of the aromatic polyamide thin film having the crosslinked structure is characterized in that it is formed by the interfacial polymerization reaction of meta-phenylenediamine and trimethoyl chloride.

Treating the ultra-thin composite membrane with an aqueous sodium hypochlorite solution.

The sulfonated poly (arylene ether sulfone) copolymer support having a thin and high porosity structure produced according to the present invention and the ultra-thin composite membrane comprising the same have excellent thermal and chemical stability and mechanical properties, However, since the internal concentration polarization can be minimized, a high water permeability and a high power density can be obtained. Therefore, the present invention can be applied to a water treatment membrane including a pressure delay osmosis process or a positive osmosis process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a photograph of a manufacturing process of a sulfonated polyarylene ether sulfone copolymer electric furnace desiccant having a crosslinked structure according to Example 1, an apparatus, and an electrodeposited film manufactured. FIG.
FIG. 2 is a photograph showing the solubility of dimethylacetamide in a crosslinked porous sulfonated polyarylene ether sulfone copolymer electrospray film prepared from Example 1. FIG. 2 (a) (C) after 24 hours].
3 is a graph showing the gel fraction (%) of an electrospray membrane prepared by preparing a porous sulfonated polyarylene ether sulfone copolymer electrospun membrane having a crosslinking structure according to Example 1, graph.
4 is a scanning electron microscope (SEM) image of a conventional polysulfone-based asymmetric composite membrane (a) and an ultra-thin composite membrane (b) prepared according to Example 2 of the present invention.
5 is a graph showing the water permeation amount and power density of an ultra-thin composite membrane according to Example 2 of the present invention.

The present invention provides a crosslinked porous sulfonated polyarylene ether sulfone copolymer support having a repeating unit represented by the following formula (1) for a water treatment separation membrane.

&Lt; Formula 1 >

(Wherein Q is a single bond or O, S, C (= O), C (= O) NH, Si (CH ₃ ) ₂ , (CH ₂ ) _{p CF 2) q (1≤q≤10),} C (CH 3) 2, C (CF 3) 2, or _{C (CH 3) (CF 3} ) , n is 0, as a repeating unit, the molar ratio of structural unit I < n < 1)

The sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure having the repeating unit represented by the above formula (1) is obtained by heat-treating a sulfonated polyarylene ether sulfone copolymer film having a repeating unit represented by the following formula (I) .

(I)

Wherein Q and n are the same as defined in the above formula (1), and the degree of sulfonation is controlled in the range of 10 to 90%

In the present invention, by using a polymer having a sulfonate group as a material for a support for a water treatment separation membrane, the hydrophilic property of the support can be increased, thereby decreasing the internal concentration polarization and increasing the anti-fouling effect. In addition, by crosslinking the polymer skeleton having a sulfonic acid group, improvement in mechanical properties and chemical stability can be achieved, and the present invention can be applied to the water treatment field.

The porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure is preferably an electrospun film in the form of a flat membrane. Generally, electrospinning can deposit hundreds of nano-sized fibers in a bottom-up manner by electrospinning to form a porous support with a thin thickness and interconnected pore structure with high porosity. Therefore, in the present invention, when the porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure is a flat membrane type electrodeposition membrane, it is preferable to use a membrane having a thickness of 20 to 50 μm and a porosity of 60 to 80% .

Since the polysulfone-based or polyethylene terephthalate-based porous support of the ultra-thin composite membrane used as a conventional water treatment membrane is thick with a thickness of 100 to 200 탆, it can be used for a pressure delayed osmosis process for energy production or a cleansing process When used as a separator, internal concentration polarization is generated inside a thick porous support, and the concentration difference, which is the driving force of water permeability, is reduced. As a result, water permeability is lowered and power density is lowered accordingly.

Therefore, according to the present invention, the thickness of the porous support obtained from the flat membrane-type electrospray membrane is as thin as 20 to 50 탆, and the porosity is as high as 60 to 80%, thereby minimizing internal concentration polarization, And thus it can be applied to the pressure delay osmosis process or the positive osmosis process.

If the thickness of the porous support is less than 20 탆, the thickness of the support may be too thin, resulting in deterioration of mechanical properties. If the thickness of the porous support exceeds 50 탆, concentration polarization may occur in the support. If the porosity of the porous support is less than 60%, the water permeability may be lowered. If the porosity exceeds 80%, the film formation is not smooth.

The present invention also relates to a porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure having a repeating unit represented by the above formula (1); And an active layer of a thin film formed on the porous support.

At this time, the active layer of the thin film formed on the porous support may be a crosslinked aromatic polyamide having a repeating unit represented by the following formula (2).

(2)

The active layer of the thin film preferably has a thickness of 50 to 300 nm. When the thickness of the active layer is less than 50 nm, it is difficult to withstand a high operating pressure when applied to a pressure delay osmosis process. When the thickness exceeds 300 nm, There is a problem in resistance.

The present invention also provides a crosslinked porous sulfonated polyarylene ether sulfone copolymer support having a repeating unit represented by the above formula (1), including the following steps.

That is, in the present invention, as the I) monomer, 4,4'-dichlorodiphenylsulfone or 4,4'-difluorodiphenylsulfone, 4,4'-biphenol compound and sulfonated 4,4'-dichlorodiphenyl Sulfone or sulfonated 4,4'-difluorodiphenylsulfone to synthesize a sulfonated polyarylene ether sulfone copolymer;

II) forming a polymer solution by dissolving the synthesized sulfonated polyarylene ether sulfone copolymer in an organic solvent by a conventional electrospinning method; And

And III) thermally crosslinking the membrane obtained in the step II), wherein the porous sulfonated polyarylene ether sulfone copolymer support has a crosslinked structure for a water treatment separator.

In step I), 4,4'-dichlorodiphenyl sulfone (DCDPS) or 4,4'-difluorodiphenyl sulfone (DFDPS), 4,4'-biphenol compound, and sulfonated 4,4'-dichlorodiphenylsulfone (SDCDPS) or sulfonated 4,4'-difluorodiphenylsulfone (SDFDPS) is reacted with a polymeric solvent such as N-methylpyrrolidone (NMP) in the presence of potassium carbonate C for 16 hours to synthesize a sulfonated polyarylene ether sulfone copolymer. The sulfonated polyarylene ether sulfone copolymer can be synthesized according to an example of the following reaction formula 1, and its specific synthesis method and analysis result are disclosed in a number of publications And thus the description thereof is omitted in the present invention (F Wang et al., J. Membr. Sci., 197 (2002), p. 231, F Wang et al., Macromol. Symp., 175 (2001), p. 387].

<Reaction Scheme 1>

The 4,4-biphenol compound represented by the following formula (II) can be used as a monomer for synthesizing the sulfonated polyarylene ether sulfone copolymer in the step (I), and the bisphenol A is more preferably used do.

&Lt;

(In the above formula (II), Q is the same as defined in the above formula (1)

Next, a polymer solution in which the sulfonated polyarylene ether sulfone copolymer synthesized in the step I) is dissolved in an organic solvent such as N-methyl pyrrolidone (NMP) is formed by electrospinning, An electrospun film in the form of a flat film is obtained.

Subsequently, the above-mentioned electrospun film is thermally crosslinked to prepare a porous sulfonated polyarylene ether sulfone copolymer support having a cross-linked structure for water treatment separator having the repeating unit represented by the above formula (1).

At this time, the thermal crosslinking is performed by heat treatment in a dimethyl sulfoxide (DMSO) steam atmosphere at 180 to 250 ° C for 1 to 12 hours.

In addition, the present invention relates to a method for producing an aromatic polyamide thin film having a crosslinked structure having a repeating unit represented by the above formula (2) on a porous sulfonated polyarylene ether sulfone copolymer support having a repeating unit represented by the above formula (1) The present invention also provides a method for producing an ultra-thin composite membrane for water treatment.

At this time, it is preferable that the active layer of the aromatic polyamide thin film having the crosslinked structure is formed by the interfacial polymerization reaction of meta-phenylenediamine (MPD) and trimethoyl chloride (TMC) according to the following Reaction Scheme 2.

<Reaction Scheme 2>

The method may further include post-treating the ultra-thin composite membrane with an aqueous solution of sodium hypochlorite (NaOCl), and the method may further include a step of partially crosslinking the porous support by the post- The decomposition of the polyamide occurs in the polyamide thin film having the structure shown in the following reaction formula (3).

<Reaction Scheme 3>

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

[Synthesis Example] Synthesis of sulfonated polyarylene ether sulfone copolymer

To a 250 mL round bottomed flask was added 4.0 mmol of disodium 3,3'-disulfonated 4,4-dichlorodiphenylsulfone (SDCDPS), 10.0 mmol of 4,4'-dichlorodiphenylsulfone (DCDPS), 14.0 mmol of bisphenol A and 30.0 mmol of potassium carbonate was added to a mixture of 10 mL of dimethylacetamide and 5 mL of toluene and the mixture was refluxed at 160 ° C. for 4 hours with a Dean-Stark apparatus. After dehydration, the reaction was heated to 190 ° C. and reacted for 16 hours, . The polymer solution was precipitated in isopropyl alcohol to precipitate a polymer. The precipitated polymer was washed with water several times and vacuum dried, and then treated with a dilute sulfuric acid solution to synthesize a sulfonated polyarylene ether sulfone copolymer. ¹ H- NMR and FT-IR. As a result, it was found that the result was in agreement with the data described in the known literature.

[Example 1] Preparation of a porous sulfonated polyarylene ether sulfone copolymer support (electrospray membrane) having a crosslinked structure

The sulfonated polyarylene ether sulfone copolymer obtained from the above Synthesis Example was dissolved in dimethylacetamide (DMAc) to prepare a 10 wt% solution. 6 ml of a polymer solution was filled in a 10 ml syringe equipped with a 23 G needle and then mounted on a syringe pump of an electrospinning device (ES-robot, NanoNC, Korea) and irradiated according to ordinary electrospinning conditions to obtain an electrospun film . The resulting electrospun film was heat-treated at 180 캜 for 5 hours in a dimethyl sulfoxide (DMSO) steam atmosphere to prepare a porous sulfonated polyarylene ether sulfone copolymer electrospun film having a crosslinked structure. It is possible to confirm that the electrospray film without any defects is stably manufactured.

[Example 2] Preparation of an ultra-thin composite membrane comprising a porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure

The porous sulfonated polyarylene ether sulfone copolymer electrospun film of crosslinked structure prepared in Example 1 was immersed in an aqueous solution of meta-phenylenediamine (MPD) of 3.5% by weight, and the excess solution was removed. 0.15 wt% of a trimesoyl chloride hexane solution was poured to perform interfacial polymerization, and then hexane was washed and allowed to stand in the air and cured in an oven at 90 ° C to crosslink the crosslinked porous sulfonated polyarylene ether sulfone copolymer support Thin film (150 nm) active layer was fabricated.

Table 1 shows mechanical properties, average pore size, and porosity of the crosslinked porous sulfonated polyarylene ether sulfone copolymer support (electrorec- tric membrane) prepared from Example 1 according to various thicknesses.

Thickness (㎛) Mechanical properties Average pore size (占 퐉) Porosity (%) Tensile Strength (Mpa) Elongation (%) 24 16.31 15.26 0.26 68.55 28 21.21 48.24 0.28 70.4 32 12.80 37.10 0.39 76.9 37 11.06 24.28 0.43 76.85

From Table 1, it can be seen that the crosslinked porous sulfonated polyarylene ether sulfone copolymer support prepared according to the present invention is much thinner than the thickness (100 to 200 탆) of the porous support used as a separator for water treatment in the prior art, And the porosity is also very high, so that the resulting water permeability can be greatly improved.

Fig. 2 shows the stability of the porous sulfonated polyarylene ether sulfone copolymer electrodeposition coating of the crosslinked structure prepared in Example 1 against dimethylacetamide. As a result, even after 24 hours, the organic solvent dimethylacetate Amide, and it was confirmed that it was not dissolved in other organic solvents other than dimethylacetamide. Thus, the crosslinked porous sulfonated polyarylene ether sulfone copolymer electrodeposition film prepared according to the present invention had a It was also found that the organic solvent was very stable.

FIG. 3 is a graph showing the gel fraction (%) of an electrospinning film prepared by varying the crosslinking time of a porous sulfonated polyarylene ether sulfone copolymer according to Example 1, using Soxhlet method [Reference: Polymer testing 22 (2003), p. (W / W ₀ ) X 100, W: weight of dry insoluble portion, W ₀ : initial weight of sample], thermal crosslinking When the reaction time exceeds 5 hours, the gel fraction exceeds 90%. When the reaction time reaches 10 hours, the gel fraction reaches 98% or more, and the crosslinking reaction is stably performed. Thus, it is confirmed that the gel fraction is insoluble in ordinary organic solvents there was.

4 shows a scanning electron microscope (SEM) image of a conventional polysulfone-based asymmetric composite membrane (a) and an ultra-thin composite membrane (b) produced according to Example 2 of the present invention. According to Example 2 of the present invention, an ultra-thin composite membrane having a polyamide thin film layer formed thereon can be observed. The thickness of the formed polyamide thin film layer is about 100 nm, which is about two times thinner than a conventional thin film layer of a polysulfone asymmetric composite membrane . Further, it was confirmed that the total thickness of the membrane was about three times thinner than that of the conventional polysulfone-based asymmetric composite membrane, and it was found that it contributes to lowering the mass transfer resistance and the internal concentration polarization.

FIG. 5 is a graph showing the water flux and power density of the ultra-thin composite membrane according to Example 2 of the present invention (HTI, a commercial polysulfone-based composite membrane manufactured by Hydration Technology Innovations) DS40 (degree of sulfonation 40%), DS40 _{500 ppm (2m)} (40% sulfonation degree, treated with NaOCl 500 ppm for 2 minutes) manufactured by the present invention. Fig. 5 The conventional HTI has a low power density of 5 W / m ² , whereas the ultra-thin composite membranes DS20 and DS40 manufactured by the present invention have a power density of about 2 times or more as about 11 W / m ² . In addition, DS40 _{500 ppm (2 m)} had a power density of 17 W / m ² , which was about 3 times higher than that of the conventional HTI. This is because the water permeability was greatly improved due to the etching effect of the ultra thin layer through NaOCl treatment Is interpreted.

As described above, the sulfonated poly (arylene ether sulfone) copolymer support having a thin and high porosity structure produced according to the present invention and the ultra-thin composite membrane comprising the same have excellent thermal and chemical stability and mechanical properties, In addition, it can be used as a water treatment separator including a pressure delay osmosis process or a positive osmosis process because it can minimize the internal concentration polarization and thereby obtain a high water permeability and a high power density.

Claims (14)

A porous sulfonated polyarylene ether sulfone copolymer support having a crosslinking structure for a water treatment separator having a repeating unit represented by the following formula (1).
&Lt; Formula 1 >

(Wherein Q is a single bond or O, S, C (= O), C (= O) NH, Si (CH ₃ ) ₂ , (CH ₂ ) _{p CF 2) q (1≤q≤10),} C (CH 3) 2, C (CF 3) 2, or _{C (CH 3) (CF 3} ) , n is 0, as a repeating unit, the molar ratio of structural unit I < n < 1) The porous sulfonated polyarylene ether sulfone copolymer support of claim 1, wherein the support is an electrospun film. The porous sulfonated polyarylene ether sulfone copolymer support according to claim 2, wherein the thickness of the electrodisplacive membrane is 20 to 50 μm and the porosity is 60 to 80%. The porous sulfonated polyarylene ether sulfone copolymer support according to any one of claims 1 to 3, wherein the water treatment separation membrane is a separation membrane for a pressure delayed osmosis process. The porous sulfonated polyarylene ether sulfone copolymer support according to any one of claims 1 to 3, wherein the water treatment separation membrane is a separation membrane for a positive osmosis process. A porous sulfonated polyarylene ether sulfone copolymer support having a crosslinking structure having a repeating unit represented by the general formula (1) of claim 1; And an active layer of a thin film formed on the porous support. The ultra-thin composite membrane for water treatment according to claim 6, wherein the active layer of the thin film is a cross-linked aromatic polyamide having a repeating unit represented by the following formula (2).
(2)

The ultra-thin composite membrane for water treatment according to claim 7, wherein the active layer of the thin film has a thickness of 50 to 300 nm. I) As the monomer, 4,4'-dichlorodiphenyl sulfone or 4,4'-difluorodiphenyl sulfone, 4,4'-biphenol compound and sulfonated 4,4'-dichlorodiphenyl sulfone or sulfonated 4 , 4'-difluorodiphenyl sulfone to synthesize a sulfonated polyarylene ether sulfone copolymer;
II) forming a polymer solution by dissolving the synthesized sulfonated polyarylene ether sulfone copolymer in an organic solvent by a conventional electrospinning method; And
III) heat-crosslinking the membrane obtained in the step II) in a steam atmosphere of dimethylsulfoxide at a temperature of 180 to 250 ° C for 1 to 12 hours to form a water-repellent layer having a repeating unit represented by the general formula (1) A process for preparing a porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure for a membrane. The process for producing a porous sulfonated polyarylene ether sulfone copolymer support according to claim 9, wherein the 4,4'-biphenol compound is represented by the following formula (II).
&Lt;

(Q in the formula (II) is the same as defined in the formula (1) delete A cross-linked aromatic polyamide thin film having a repeating unit represented by the general formula (2) of claim 7 on a porous sulfonated polyarylene ether sulfone copolymer support having a crosslinked structure having a repeating unit represented by the general formula (1) And forming an active layer of an ultra-thin composite membrane for water treatment,
Further comprising the step of post-treating the ultra-thin composite membrane with an aqueous sodium hypochlorite solution. 13. The method according to claim 12, wherein the active layer of the aromatic polyamide thin film having a crosslinked structure is formed by interfacial polymerization between meta-phenylenediamine and trimethoyl chloride. delete

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