KR101448551B1 - Anti-biofouling water treatment membrane and method of preparing the same - Google Patents

Abstract

A thiol group-containing polymer separating membrane, and metal nanoparticles covalently bonded to the thiol group, and a method for producing the same.

Description

[0001] The present invention relates to an anti-biofouling water treatment membrane and a method of preparing the same,

The present invention relates to a separation membrane improved in biofouling and a method for producing the same. More particularly, the present invention relates to a separation membrane improved in biofouling caused by adhesion and proliferation of microorganisms on the surface of a separation membrane with excellent water permeability and a preparation method thereof.

The water treatment method using a membrane has recently been applied to a variety of water treatment fields with a small installation space, excellent processing capacity, and low operating cost compared with the existing technologies. Specifically, microfiltration (MF) / ultrafiltration (UF) membranes are applied to sewage treatment plants and reverse osmosis (RO) membranes are used for seawater desalination. In addition, water treatment using membranes is used in many industrial fields such as household, medical, and industrial fields.

Most of the materials to be removed by water treatment are microorganisms in water. When the raw water containing microorganisms is treated with a separation membrane, they cause adsorption and proliferation on the separation membrane surface, thereby causing biofouling, which is a phenomenon of blocking the pores of the separation membrane, thereby deteriorating the performance of the separation membrane and greatly shortening the life span. Various methods such as membrane surface hydrophilic modification or surface membrane hydrophilic polymer coating, membrane material and antibacterial functional nanoparticle blending have been attempted to suppress biofouling of the membrane. The introduction of hydrophilicity into the membrane, the first method, is a method of inhibiting the surface adsorption of microorganisms with surface hydrophobic properties. ( Chem. Rev. 2010 , 110 , 2448-2471) However, the above method has an effect of suppressing biofouling in short-time use, but has a problem in that it is ineffective in long-term use. The second method of introducing the antibacterial functional nanoparticles inhibits the biofouling by originally blocking the microorganism from breeding. Recent studies have used silver nanoparticles known to be able to maintain excellent antimicrobial properties for a long time in most pathogenic microorganisms in order to impart antimicrobial functionality to the membranes. ( Water Res. 2009 , 43 , 715-723) In this study, silver nanoparticles were dispersed together in a polymer solution of a separation membrane and then prepared as a separation membrane to prepare silver nanoparticles in a separation membrane. The separation membrane with silver nanoparticles effectively inhibited the growth of pathogenic microorganisms. However, the silver nanoparticles have been introduced without any specific binding to the separation membrane and have been shown to be detached continuously during the water treatment process.

Therefore, in order to have a superior biofouling inhibiting function, it is necessary to develop a technology capable of maintaining excellent antimicrobial activity for a long time during the use of the separator.

The present invention provides a separation membrane capable of suppressing biofouling in which microorganisms adhere to the surface of a separation membrane while having excellent water permeability and a method for producing the same.

In order to solve the problems of the present invention,

According to an aspect of the present invention,

A thiol group-containing polymer separating membrane, and metal nanoparticles covalently bonded to the thiol group.

And the thiol group-containing polymer separator may have a thiol group-containing compound located on at least one of both sides of the polymer substrate and the polymer substrate.

The polymer substrate may be formed of at least one polymer selected from the group consisting of polysulfone, polyethersulfone, polyvinylidene fluoride, and polyacrylonitrile.

The thiol group-containing compound may be used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the polymer base material.

The thiol group-containing compound may be a molecule or a polymer containing at least one thiol group in the molecule.

The thiol group-containing compound can be obtained by modifying the hydroxyl group of a molecule or a polymer having at least one hydroxyl group in the molecule.

The molecule or polymer having at least one hydroxyl group in the molecule may be at least one compound selected from the group consisting of polyethylene block polyethylene glycol copolymer, polyethylene glycol, polyvinyl alcohol random ethylene copolymer, and polyvinyl alcohol.

The metal nanoparticles may be nanoparticles of at least one metal selected from the group consisting of silver, copper, gold, palladium, and platinum.

The content of the metal nanoparticles may be 0.01 to 5 on the basis of 100 parts by weight of the thiol group-containing polymer separator.

Wherein the inner biofouling water treatment separator has a surface layer having micropores having a pore size of 0.001 to 1 mu m and a surface layer having a finger-like or sponge-like pore structure having a thickness of 10 to 500 mu m An inner support layer.

According to another aspect of the present invention,

Preparing a polymer dope solution by dissolving a thiol group-containing compound and a polymer for a substrate in a solvent;

Coating the prepared polymeric dope solution on a substrate, and impregnating the coated substrate with a non-solvent to form a thiol group-containing polymer separator; And

Impregnating the metal nanoparticle colloid solution prepared by stirring a dispersion containing a metal precursor, a nanoparticle stabilizer and a dispersion medium, and then adding a reducing agent to the stirred dispersion, impregnating the metal nanoparticle with the thiol group- And introducing the covalent bond to the polymer separator by covalent bonding with the thiol group.

According to an embodiment of the present invention, the polymer separator may be modified with a thiol group to form a covalent bond with the antibacterial metal nanoparticles, thereby forming an inner biofouling functional separation membrane in which the metal nanoparticles are uniformly chemically bonded to the separation membrane surface . Accordingly, the bio-fouling function is well developed due to the metal nanoparticles well dispersed on the surface of the separation membrane, and the bio-fouling function is well maintained because the water is easily desorbed and discharged to the outside for a long time.

1 is a general schematic diagram according to an embodiment of the present invention.
2 is a HR-TEM image of metal nanoparticles according to an embodiment of the present invention.
3 is a synthetic reaction scheme for preparing a polymer having a thiol group according to an embodiment of the present invention.
FIG. 4 is a graph showing FT-IR of a polymer having a thiol group according to an embodiment of the present invention.
5 is a graph of ¹ H NMR measurement of a polymer having a thiol group according to an embodiment of the present invention.
FIG. 6 is a graph showing the relationship between the amount of a polysulfone modified with a polysulfone (a), (b) a polysulfone modified with a thiol group, (c) a pure polyvinylidene fluoride used in the production of an internal biofouling water treatment separator according to an embodiment of the present invention, (d) a cross-sectional FE-SEM picture of polyvinylidene fluoride modified with a thiol group.
(B) a polysulfone modified with a thiol group and introduced with silver nanoparticles, (c) a polysulfone modified with a poly (meth) acrylate, Vinylidene fluoride, (d) a polyvinylidene fluoride modified with a thiol group and having silver nanoparticles incorporated therein.
FIG. 8 is a graph showing the results of a comparison between a polysulfone modified with (a) a thiol group and a silver nanoparticle-introduced polysiloxane used for manufacturing an inner biofouling water treatment separation membrane according to an embodiment of the present invention, and (b) And the surface of each separation membrane of polyvinylidene fluoride was measured by EDXS.
FIG. 9 is a graph showing the extent of removal of silver nanoparticles, which are internal biofouling metal nanoparticles introduced into a water treatment separation membrane, from a separation membrane during a water permeation process in the water treatment separation membrane according to Comparative Examples 1 and 2. FIG.
10 is a graph showing the XPS measurement of the membrane surface before and after permeation of the membrane in the water treatment membranes according to Comparative Examples 1 and 2. FIG. ((a): Comparative Example 1, (b): Example 2)
FIG. 11 shows the results of (a) the pure polyvinylidene fluoride separation membrane (b) of Comparative Example 2, and (b) the polyvinylidene fluoride separation membrane according to Comparative Example 2 after the separation membrane was impregnated into the saturated coliform suspension (~10 ⁹ CFU / ) FE-SEM photographs of each surface of a polyvinylidene fluoride separation membrane into which silver nanoparticles are introduced via the chemical bond of Example 2.
12 is a graph showing a change in water permeability after inoculation of E. coli into the polyvinylidene fluoride separation membrane of Comparative Example 2 and the silver nanoparticle-introduced polyvinylidene fluoride separation membrane through chemical bonding of Example 2;

Hereinafter, the present invention will be described in detail. The terms and words used herein should not be construed as limiting the invention to any ordinary or preliminary meaning and the inventor may properly define the concept of the term to best describe its invention And should be construed in accordance with the principles and meanings and concepts consistent with the technical idea of the present invention.

The inner biofouling water treatment separator according to one aspect of the present invention comprises a thiol group-containing polymer separator and metal nanoparticles covalently bonded to the thiol group.

The thiol group-containing polymer separation membrane may be a single polymer type in which a thiol group is introduced into a polymer capable of being formed as a separation membrane, or may be a mixture form in which a thiol group-containing compound is added to a polymer capable of forming a membrane as a separation membrane.

In the latter case, the thiol group-containing polymer separation membrane may comprise a polymer base material and a thiol group-containing compound located on at least one of both surfaces and the inside of the polymer base material.

The polymer to be applied to the polymer substrate may be any polymer capable of forming a film, and specifically a polymer capable of forming a film through NPS (Nonsolvent Induced Phase Separation). Examples of the polymer include polysulfone, But is not limited to, at least one selected from the group consisting of polyethersulfone, polyvinylidene fluoride, and polyacrylonitrile. The weight-average molecular weight of the polymer is 50,000 or more, more preferably 50,000 to 1,000,000, and most preferably 50,000 to 600,000.

The thiol group-containing compound may be a molecule or a polymer containing at least one thiol group in the molecule, which may be obtained by using commercially available materials, or by modifying a hydroxyl group of a hydroxyl group-containing molecule or polymer with a thiol group .

For example, by reacting a polymer having a hydroxyl group with a mercaptoacetic acid solution, the hydroxyl group of the polymer can be modified to a thiol group.

As such a molecule or polymer having at least one hydroxyl group in the molecule, there is at least one compound selected from the group consisting of polyethylene block polyethylene glycol copolymer, polyethylene glycol, polyvinyl alcohol random ethylene copolymer, and polyvinyl alcohol. But is not limited thereto.

At this time, the content of the thiol group-containing compound may be, for example, 1 to 20 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of the polymer base material.

The content of the total thiol group can be controlled by adjusting the content of the thiol group-containing compound, and finally, the total thiol group content can be controlled in the inner biofouling water treatment separator. The total thiol group content is covalently bonded to the thiol group, And plays an important role in controlling the content of antimicrobial metal nanoparticles exhibiting biofouling properties.

At this time, the total thiol group content of the polymer membrane may be 0.01 to 0.5, preferably 0.05 to 0.15 based on the total weight of the polymer membrane. When the total thiol group content of the polymer membrane satisfies this range, it provides appropriate conditions for binding with the introduced metal nanoparticles. On the other hand, when the amount of the thiol group introduced is too small beyond the above range, the number of functional groups capable of binding to the metal nanoparticles becomes absolutely insufficient. On the other hand, when the thiol group is introduced too much, And in addition, a disulfide bond in the thiol period may occur, which may destroy the functional group capable of binding to the metal.

The metal nanoparticles can be used without restriction as long as they are covalently bonded to the thiol group and can impart antimicrobial and anti-Pauli properties to the polymer separation membrane. Specifically, the metal nanoparticles have an electronegativity of 1.9 to 2.54 and an ion radius Nano particles such as silver, copper, gold, palladium, platinum and the like with an oxidation index of +1 or +2 can be used.

The average diameter of the metal nanoparticles may be, for example, 1 to 300 nm, preferably 1 to 50 nm. When the average diameter of the metal nanoparticles satisfies the above range, the surface energy of the particles becomes higher than that of the conventional bulk state, so that new surface characteristics of the metal are exhibited on the nanoparticles. In particular, The particles exhibit antimicrobial activity. Particularly, it is well known that the metal element of silver is slightly antimicrobial even in the bulk state, but when it becomes nanoparticle, the effect is greatly increased and it has a strong antibacterial effect on various kinds of microorganisms. Therefore, metal nanoparticles satisfying the above conditions have high antibacterial properties and can be used as biofouling materials.

The content of the metal nanoparticles covalently bonded to the thiol group of the polymer separator may be 0.01 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the thiol group-containing polymer separator. When the content of the metal nanoparticles satisfies the above range, excellent biofouling properties can be provided to the separator for a long time. On the other hand, when the amount is too small, the biofouling property is expected to decrease drastically. If the amount of the biofouling agent is too large, the separation of the nanoparticles may occur during the use of the separation membrane.

The water treatment separation membrane according to one embodiment of the present invention is prepared by a non-solvent-derived phase separation method (NIPS), and the skin layer has small pores to perform a separation function of a substance dissolved in water, Like or sponge-like pore structure, and can have an asymmetric structure as a whole.

Specifically, the surface layer may have micropores having a pore size of 0.001 to 1 μm, and the internal support layer may have a finger-like or sponge-like pore structure having a thickness of 10 to 500 μm. Lt; / RTI >

According to another aspect of the present invention, there is provided a method of manufacturing an internal biofouling water treatment separation membrane,

Preparing a polymer dope solution by dissolving a thiol group-containing compound and a polymer for a substrate in a solvent; Coating the prepared polymeric dope solution on a substrate, and impregnating the coated substrate with a non-solvent to form a polymer separator; And impregnating the polymer nanoparticle with the colloidal solution of metal nanoparticles prepared by stirring a dispersion comprising a metal precursor, a nanoparticle stabilizer, and water, and then adding a reducing agent to the stirred dispersion, And covalently bonding the polymer to the polymer separator.

 Hereinafter, a method for manufacturing the inner biofouling water treatment separation membrane will be described in detail.

First, a polymer for substrate and a thiol group-containing compound capable of forming a separation membrane to contain the thiol (-SH) on both surfaces and inside of the polymer separator are dissolved in a solvent together to prepare a polymer dope solution do.

Thereafter, the polymeric dope solution is coated on a substrate, and then the coated substrate is impregnated with a non-solvent to form a polymer membrane by non-solvent-induced phase separation.

That is, when a thiol group-containing compound, such as a thiol group-modified molecule or a polymer, is added to an organic solution in which a polymer capable of forming a film is dissolved, a thiol group is introduced on the surface of the polymer separation membrane or inside the separation membrane during the non- A polymer membrane modified with a thiol group can be obtained.

The thiol group-containing compound used for introducing the thiol group into the polymer separator may be a molecule or polymer having a thiol group originally, or a molecule or polymer having a number average molecular weight of 100 to 100,000 and having a hydroxyl group (-OH) With a thiol group.

As described above, the molecule or the polymer having at least one hydroxyl group in the molecule may be at least one selected from the group consisting of polyethylene block polyethylene glycol copolymer, polyethylene glycol, polyvinyl alcohol random ethylene copolymer, and polyvinyl alcohol But are not limited thereto.

In addition, a dispersion containing a metal precursor, a nanoparticle stabilizer, and a dispersion medium is stirred, and then a reducing agent is added to the stirred dispersion to prepare a solution of a metal nano-particle colloid.

The kind of the dispersion medium constituting the metal nano-particle colloid solution is not particularly limited, and for example, ethanol, water and the like can be used. The metal precursor refers to a precursor of the antibacterial metal nanoparticles which is finally introduced into the water treatment separator. Materials of the metal nanoparticles such as nitrate, chloride and the like may be used.

The metal nanoparticle colloid solution may further contain known nanoparticle stabilizers and the like in order to ensure stable dispersion of the metal nanoparticles. Examples thereof include triosodium citrate, citric acid pluronic copolymer, and the like , But is not limited thereto.

Thereafter, the method of treating the colloidal solution of the metal nanoparticles with the polymer membrane formed by the non-solvent-derived phase separation method may be any conventional method, and examples thereof include a coating method and a dipping method.

Finally, the result of treating the polymer membrane with the metal nanoparticle colloidal solution is obtained and stored. A washing step may be added before or after this step if necessary, and the resultant product can be stored in water or dried.

The metal nanoparticles exhibiting antibacterial activity are chemically bonded to the polymer membrane by forming a covalent bond with the thiol group of the polymer membrane. As a result, the dispersibility of the metal nanoparticles in the polymer separator is improved, and the metal nanoparticles do not desorb even after prolonged use, thereby exhibiting excellent in-vivo fouling functionalities.

In addition, due to the dispersion of the metal nanoparticles, the surface area that can be in contact with microorganisms and the like is formed to be very wide, thereby exhibiting high internal biofouling performance.

FIG. 1 schematically shows steps of manufacturing an internal biofouling water treatment membrane according to an embodiment of the present invention.

That is, first, a polymer dope solution obtained by dissolving a thiol group-containing polymer-containing compound and a polymer for a base material, into which a thiol group-containing linker has been introduced, is coated on a substrate and then solidified using non-solvent-derived phase separation (NIPS) A polymer separator introduced on the surface of the glass is formed, and then the polymer separator is impregnated with a silver nanoparticle colloid solution using silver nanoparticles as metal nanoparticles to produce an inner biofouling water treatment separator into which silver nanoparticles are introduced.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the following examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the following embodiments. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

Example 1

Preparation of metal nanoparticle colloids

(1) Production of silver nanoparticle colloid

An aqueous solution containing AgNO ₃ as a silver precursor and trisodium citarate as a nanoparticle stabilizer were added to the glass bottle at the same concentration and stirred for 5 minutes or more at room temperature. Then, NaBH ₄ , a reducing agent, was added to the stirred silver precursor / nanoparticle stabilizer solution A small amount of silver nanoparticle colloid was prepared. At this time, the average particle diameter of the silver nanoparticles was about 10 nm.

As shown in FIG. 2, the silver nanoparticles were confirmed to have spherical morphology through HR-TEM.

Preparation of polymer membrane modified with thiol group

(1) Preparation of a polymer additive having a thiol group

Polyethylene block polyethylene glycol copolymer (PE- b- PEG) (Sigma Aldrich, number average molecular weight 2,250, polyethylene content 20 wt%, polyethylene glycol content 80 wt%) was added to a toluene solvent at 80 to 110 캜 It dissolved at the temperature. In the next step, a solution prepared by mixing mercaptoacetic acid and concentrated sulfuric acid was added slowly and maintained for 2 hours to obtain a thiolated polyethylene thiol group, in which the hydroxyl group at the terminal of the polyethylene block polyethylene glycol copolymer was converted into a thiol group by the esterification reaction Block polyethylene glycol copolymer was prepared. Infrared spectroscopy (IR spectroscopy) and 1 98% or more of the hydrogen nuclear magnetic resonance spectroscopy ⁽¹ H NMR spectroscopy) the polyethylene block of polyethylene of a terminal hydroxyl group of the glycol copolymer from the product was confirmed to be a thiol group substituted with (4, 5 ). The reaction of converting the hydroxyl group of the polyethylene block polyethylene glycol copolymer to the thiol group is shown in FIG. 3 to 5, m represents the number of ethylene repeating units, n represents the number of ethylene glycol repeating units, m is 4 to 20, n is 6 to 50, and n is larger than m.

(2) Thin-film modified polymer membrane

To modify the surface and interior of the polymer separator with a thiol group, the thiolated polyethylene block polyethylene glycol copolymer prepared by the above-described method was mixed with a polysulfone polymer (BASF, Ultrason S6010, weight average molecular weight of 78,000) and N-methylpyrrolidone (NMP) solvent to prepare a polymer dope solution. The amount of the thiolated polyethylene block polyethylene glycol copolymer added was 5 to 15 wt% of the polysulfone polymer and the amount of the polysulfone polymer dissolved in the NMP solvent was 15 wt%. The polymeric dope solution was dropped on top of the glass plate, and then made uniform to a certain thickness using a casting knife. Then, the polymer electrolyte membrane was impregnated with a glass plate to prepare a polymer membrane. The thiolated polyethylene block polyethylene glycol copolymer added as an additive remains in the polysulfone polymer. The polyethylene block portion of the thiolated polyethylene block polyethylene glycol copolymer is highly compatible with the polysulfone polymer. At this time, the thickness of the polymer separator is 100 to 200 탆 as shown in FIG. 6, and shows a cross-sectional profile of the finger shape.

Introducing bio-fouling metal nanoparticles into a polymer membrane

In order to introduce silver nanoparticles having biofouling properties into the polymer membrane, a silver nanoparticle colloid solution adjusted to pH 12 was impregnated with a polymer membrane modified with a thiol group, and then stirred at room temperature for 12 hours or longer to form silver nanoparticles Polymer membrane, washed and stored in distilled water.

The polymer separator used herein is a thiol-modified polysulfone or polyvinylidene fluoride prepared by the above-described method, and the method of introducing the silver nanoparticles into the two separators is the same.

Example 2

Except that polyvinylidene fluoride (PVDF) (Solvay chemicals, Solef 1015, weight average molecular weight: 570,000) was used instead of polysulfone polymer and dimethyl acetamide (DMAc) was used instead of N-methylpyrrolidone , An inner biofouling water treatment separation membrane was prepared in the same manner as in Example 1. [

Comparative Example 1

Except that a polymeric dope solution of pure polyvinylidene fluoride (PVDF) not containing a polymer additive having a thiol group was used.

Comparative Example 2

A separation membrane was prepared in the same manner as in Example 1, except that a pure polyvinylidene fluoride (PVDF) polymer dope solution was used and silver nanoparticles were not introduced.

Surface morphology analysis

Referring to FIG. 7, the morphology of the separation membrane into which the silver nanoparticles were introduced using the FE-SEM was analyzed. As a result, the shape of the particles on the surface of the separation membrane was not observed before the introduction of the silver nanoparticles, It was confirmed that the particles are present on the surface of the separator when introduced into the fluoride polymer membrane. As shown in FIG. 8, it was confirmed that a specific peak corresponding to silver was observed through EDXS analysis.

Evaluation of the content of metal nanoparticles introduced

The separation membrane prepared in Example 2 and Comparative Example 1 was measured by the ICP-AES method. As a result, it was found that 0.534 mg of Ag was introduced into the membrane area of 13.4 cm ² in Example 2, 0.115 mg of Ag was introduced into Comparative Example 1 Respectively. From these results, it can be seen that there is a considerable difference in the content of silver nanoparticles originally introduced when a polymer substrate into which a thiol group is introduced is used.

Evaluation of metal nanoparticle desorption

FIGS. 9 and 10 show experimental results in which pure water is continuously permeated in order to determine whether or not silver nanoparticles introduced into the separation membrane are desorbed. According to the results of this experiment, it is seen that when silver nanoparticles are introduced into the separation membrane of pure polyvinylidene fluoride (Comparative Example 1), silver nanoparticles do not have any special interaction with the separation membrane and are easily separated from the separation membrane surface. Specifically, when 500 mL of pure water was permeated, about 43% (43.6%) of silver removal was observed. When 2 L of pure water was permeated, it was confirmed that more than 50% (52.3%) of the introduced silver was desorbed from the separation membrane . However, it was confirmed that the separation membrane in which the silver nanoparticles were introduced into the covalent bond by the thiol group (Example 2) did not cause the leakage of the silver nanoparticles. (See Fig. 9)

As a result of analyzing the content of silver atoms present on the surface of the membrane after 2 L of pure permeation, the content of silver element was significantly reduced from 1.87 wt% to 0.87 wt% in the membranes incorporating silver nanoparticles without binding 10 (a)), it was confirmed that the content of the silver element was well maintained in the separation membrane into which silver nanoparticles were covalently bonded (see FIG. 10 (b)).

Bio-fouling test

Escherichia coli was selected as a test strain in order to evaluate the biofouling property of the inner biofoultry water treatment membranes of Examples 1 and 2 prepared above.

In the first experiment, Escherichia coli cells were immersed in an aqueous solution of Escherichia coli (~ 10 ⁹ CFU / mL) grown to saturation and then exchanged at 37 ° C for 4 hours.

11, it was observed that Escherichia coli was attached to the surface of the pure polyvinylidene fluoride separation membrane in which the internal biofouling-type silver nanoparticles were not introduced according to Comparative Example 2 (FIG. 11 (a)), , And on the surface of the polyvinylidene fluoride separation membrane to which silver nanoparticles are bound according to Example 2, the original shape of E. coli was destroyed and died (see FIG. 11 (b)). Through this, it was confirmed that the silver nanoparticles introduced to give the biofouling inhibited the growth of microorganisms.

In the second experiment, Escherichia coli was inoculated on the surface of the membrane, and then the nutrient (LB broth: 1 g / L) easily permeable to E. coli was permeabilized for 20 hours.

In FIG. 12, the pure polyvinylidene fluoride separation membrane according to Comparative Example 2 sharply decreases the water permeability after inoculation of E. coli, reaching the lowest water permeability of about 1% of the pure water permeability after 12 hours, It was confirmed that the polyvinylidene fluoride separation membrane having the silver nanoparticles incorporated therein maintained a water permeability of 20 to 21% of the pure water permeability. The decreasing water permeability is thought to be caused by the microorganisms attached to the surface of the membrane and by the concentration of nutrients on the surface of the membrane.

From the above two evaluations, it was confirmed that the silver nanoparticles introduced into the membrane by chemical bonding are effective in suppressing biofouling even in the actual water treatment environment in order to impart the biofouling property.

Claims (11)

A thiol group-containing polymer separator, and a metal nanoparticle covalently bonded to the thiol group, wherein the thiol group-containing polymer separator contains a thiol group-containing compound located on at least one of both sides of the polymer base and the polymer base, Wherein the biofouling water separating membrane comprises: delete The method according to claim 1,
Wherein the polymer substrate is formed of at least one polymer selected from the group consisting of polysulfone, polyethersulfone, polyvinylidene fluoride, and polyacrylonitrile. The method according to claim 1,
Wherein the thiol group-containing compound is 1 to 20 parts by weight based on 100 parts by weight of the polymer base material. The method according to claim 1,
Wherein the thiol group-containing compound is a molecule or a polymer containing at least one thiol group in the molecule. 5. The method of claim 4,
Wherein the thiol group-containing compound is obtained by modifying a hydroxyl group of a molecule or a polymer having at least one hydroxyl group in the molecule. The method according to claim 6,
Wherein the molecule or polymer having at least one hydroxyl group in the molecule is at least one compound selected from the group consisting of polyethylene block polyethylene glycol copolymer, polyethylene glycol, polyvinyl alcohol random ethylene copolymer, and polyvinyl alcohol. Biofouling water treatment membrane. The method according to claim 1,
Wherein the metal nanoparticles are nanoparticles of at least one metal selected from the group consisting of silver, copper, gold, palladium, and platinum. The method according to claim 1,
Wherein the content of the metal nanoparticles is 0.01 to 5 parts by weight based on 100 parts by weight of the thiol group-containing polymer separating membrane. The method according to claim 1,
Wherein the inner biofouling water treatment separator has a surface layer having micropores having a pore size of 0.001 to 1 mu m and a surface layer having a finger-like or sponge-like pore structure having a thickness of 10 to 500 mu m An inner support layer formed on the inner surface of the inner biofouling layer. Preparing a polymer dope solution by dissolving a thiol group-containing compound and a polymer for a substrate in a solvent;
Coating the prepared polymeric dope solution on a substrate, and impregnating the coated substrate with a non-solvent to form a thiol group-containing polymer separator; And
Impregnating the metal nanoparticle colloid solution prepared by stirring a dispersion containing a metal precursor, a nanoparticle stabilizer and a dispersion medium, and then adding a reducing agent to the stirred dispersion, impregnating the metal nanoparticle with the thiol group- And introducing the covalent bond to the polymer separator by covalent bonding with the thiol group.

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