KR20140073090A - Manufacturing method of polysulfone membrane has efficient microorganism resolving power and polysulfone membrane produced thereof - Google Patents

Abstract

The present invention relates to a manufacturing method of a polysulfone-based membrane having an excellent microorganism removal performance, and a polysulfone-based membrane manufactured thereby, which has advantage of providing an excellent microorganism removal performance. Furthermore, the polysulfone-based membrane of the present invention maintains the microorganism removal performance for a long time by a continuous removal performance even after time passes and is able to remove ultra-fine microorganisms at a high flux.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polysulfone-based separator and a polysulfone-based separator,

The present invention relates to a method for producing a polysulfone-based membrane having excellent microbial removal ability and a polysulfone-based membrane produced thereby, and more particularly, to a method for producing a polysulfone-based membrane having improved ability to remove microorganisms, The present invention relates to a method for producing a polysulfone-based membrane having excellent ability to remove microorganisms and a polysulfone-based membrane prepared thereby.

Generally, there are numerous ionic substances and chemicals, including natural organic matter (NOM), in water, and they are not removed in the process of water treatment but act as a cause of generating new pollutants. In addition, the presence of pathogenic microorganisms, which have not been removed by chlorine disinfection, has recently been controversial. Pathogenic microorganisms, such as viruses, crytosphoridium, and Giardia, are released into the environment through human and animal feces and are present in surface water and groundwater as well as in sewage. Viruses are 0.02-0.09 ㎛ in size, bacteria are 0.4-14 ㎛ in width and 0.2-1.2 ㎛ in width. Protozoa such as cryptosporidium and xylydia are relatively large compared to viruses and bacteria. Because viruses are very small in size, they are hardly treated by general filtration. They form stable cysts and survive for several months in water.

At present, in order to remove trace contaminants in water, advanced coagulation treatment, activated carbon adsorption and membrane filtration are proposed in the water treatment process. Recently, a large-scale study on the water treatment process using membranes is underway. Particularly, membrane filtration has been recently studied and commercialized in advanced water treatment process. However, it is still not widely used due to economical cost and technical problems. Existing filters including membranes classified as reverse osmosis membrane (RO), nanofiltration membrane (NF), ultrafiltration membrane (UF), and microfiltration membrane (MF), use conventional pore size to measure contaminants in water It is a system to remove.

The main mechanism for removing contaminants from the membrane is to remove bacteria, viruses and organic contaminants floating in the water by applying a sieve effect, ie removal by particle size. In addition to the removal by the particle size, electrostatic adsorption according to the surface charge of the separation membrane filters the microorganisms in the water. This method has been studied for its high permeability and high particle removal performance compared to a low operating pressure.

The microfibre filter widely used for conventional water treatment has a disadvantage in that the efficiency is low because the filtration area is small and there is no electrostatic force. The membrane filter has a disadvantage in that the filtration efficiency is high but the pressure loss is large. Accordingly, studies have been made to increase the filtration efficiency of the fiber filter and decrease the pressure loss by applying an electrostatic force to the nano-size pore-sized fiber filter to compensate for the disadvantages of the microfiber filter and the membrane filter.

For example, there has been a technique relating to a separation membrane prepared by preparing charged alumina nanofibers and adding the charged alumina nanofibers to glass fibers, and a technique of adding an amine compound in the production of a separation membrane.

However, since this technique uses glass fiber, there is a problem of harmfulness such as carcinogen, and there is a concern that it is not suitable for use in a water treatment process, and a product group can not be diversified due to a compound added during production using glass fiber.

In addition, there is a method of manufacturing a charged filter material by electrospinning a polymer solution by a corona discharge by a charge applying method using a corona or a plasma at the time of processing, but the chargeability of the produced filter material rapidly decreases .

In addition, the prior art has a problem that the performance of the separation membrane capable of removing nanoparticles of a nanoparticle size while having a high flow rate is lowered and the sustainability is also inferior in the ability to remove microorganisms.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a polysulfone separator having improved particle removal performance due to electrostatic adsorption while remarkably improving the ability to remove microorganisms.

Another object of the present invention is to provide a method for producing a polysulfone-based membrane capable of removing microorganisms capable of continuously removing microorganisms even after passage of a seal, and a polysulfone-based membrane produced thereby.

In order to solve the above-mentioned problems, the present invention relates to (1) a nanoparticle metal compound; And a solvent; (2) immersing the polysulfone-based separator in the sol-coating solution; And (3) drying the polysulfone separator after the immersion. And a method for producing the polysulfone-based membrane.

According to a preferred embodiment of the present invention, the nanoparticle metal compound of step (1) may be an aluminum salt, preferably aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), aluminum isoprope oxide May be any one or more selected from the group consisting of -CH (CH ₃ ) ₂ ) ₃ , alumina formacetate ('AFA') and aluminum nitroformacetate ('ANFA' The metal compound may be an aluminum isoprope oxide (Al (O-CH (CH ₃ ) ₂ ) ₃ , and the nanoparticle metal compound in the step (1) % ≪ / RTI > by weight.

According to a preferred embodiment of the present invention, the sol-coating solution of step (1) may further include a binder material, and may further include a silane coupling agent. The method may further include UV irradiation or heat treatment after the step (3).

Another aspect of the present invention relates to a polysulfone separator; And a coating layer containing a nano-metal formed on the polysulfone-based separation membrane. Preferably, the coating layer may further include a binder material. Most preferably, the binder material is a silane coupling agent and an organic silicon And a compound selected from the group consisting of compounds.

According to a preferred embodiment of the present invention, the nano metal may be aluminum, and the thickness of the nano metal-containing coating layer may be 40 to 500 nm.

The polysulfone-based membrane having excellent microbial removal capability of the present invention has remarkably improved ability to remove microorganisms, and has a particle removal performance due to continuous electrostatic adsorption over time, so that the polysulfone-based membrane having excellent ability to remove microorganisms, And a polysulfone separator prepared by the method.

Hereinafter, the present invention will be described in more detail.

As described above, conventionally, there is a problem of harmfulness such as carcinogen due to the use of glass fiber, and there is a concern that it is suitable for use in a water treatment process, and a problem that a product group can not be diversified due to a compound added during production using glass fiber there was.

In addition, there is a method of manufacturing a charged filter material by electrospinning a polymer solution by a corona discharge by a charging method using a corona or a plasma at the time of processing, but the chargeability of the prepared filter material rapidly decreases over time There was a problem.

According to one aspect of the present invention, there is provided a method of preparing a nanoparticle metal compound, comprising: (1) preparing a nanoparticle metal compound, a sol coating solution containing a solvent; (2) immersing the polysulfone-based separator in the sol-coating solution; And (3) drying the polysulfone separator after the immersion. The present invention provides a method for producing a polysulfone-based membrane having excellent microbial removal ability.

First, the step of preparing the sol-coating solution containing the nanoparticle metal compound and the solvent as the step (1) will be described.

In the step (1) of the present invention, as a step of preparing a sol-coating solution, a sol-coating solution necessary for effectively removing microorganisms by applying a charge to the polysulfone-based membrane is prepared.

In the present invention, the sol coating solution means a colloid solution in which the synthesized nanometal is dispersed.

According to a preferred embodiment of the present invention, the nanoparticle metal compound may be an aluminum salt, and preferably the aluminum salt is preferably aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), aluminum isoprope oxide (O-CH (CH ₃ ) ₂ ) ₃ ), alumina formacetate ('AFA') and aluminum nitroformacetate ('ANFA'), and more preferably, The metal compound may be an aluminum isoprope oxide (Al (O-CH (CH ₃ ) ₂ ) ₃ ) The size of the nanoparticle metal compound may be 10-300 nm.

The solvent used in the preparation of the sol coating solution is not particularly limited and may be used in ethanol, acetone, chloroform, water and ethyl acetate, and most preferably a water solvent.

According to a preferred embodiment of the present invention, the nanoparticle metal compound of the step (1) may include 1 to 15% by weight based on 100% by weight of the sol coating solution, If the amount is less than 10 wt%, the microbial removal effect may be insufficient. If the amount is more than 15 wt%, there may be a problem that the specific surface area is reduced due to agglomeration of the synthesized nanomaterial.

 The organic acid may be added as a catalyst for synthesizing the nanometal by hydrolysis of the aluminum salt in the preparation of the sol coating solution. The organic acid may be used without particular limitation, and preferably used in nitric acid, sulfuric acid, hydrochloric acid, And most preferably nitric acid can be used.

Meanwhile, the sol-coating solution of step (1) may further contain a binder material. In the present invention, when the sol-coating solution is coated on the polysulfone-based separation membrane, the effect of sustaining the ability to remove microorganisms can be maintained. Further, the binder is preferably a silane coupling agent (See Table 1).

Examples of the silane coupling agent include tetraalkoxysilane, alkyltrialkoxysilane, vinyltrialkoxysilane, aminoalkyltrialkoxysilane, and acryloxyalkyldimethoxysilane. Specific examples thereof include tetramethoxysilane, tetraethoxysilane , Methyltrimethoxysilane, vinyltriethoxysilane, aminopropyltriethoxysilane, and methacryloxypropyltrimethoxysilane. The silane coupling agent may be used in combination with the sol-coating solution The silane coupling agent may further comprise 1 to 5% by weight based on 100% by weight of the composition.

The sol-coating solution may further include an initiator that absorbs ultraviolet rays and heat energy to generate radicals or cations to initiate polymerization. Preferably, the initiator is an amine-based initiator, Oxides and the like, and examples of the photoinitiator include benzophenone, azobisisobutyronitrile, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin iso Butyl ether, acetophenone, dimethyl anino acetophenone, benzoin isopropyl ether, and the like, and may be any one selected from the above initiators. The initiator may be used in an amount of 0.01 to 1 wt% based on 100 wt% %. ≪ / RTI >

Next, the step of immersing the polysulfone-based separator in the sol-coating solution of step (2) will be described.

In the present invention, the polysulfone-based separator may be a polysulfone-based separator prepared by a conventional method, and the method of producing the polysulfone-based separator may be preferably performed by the following method.

8 to 20% by weight of a polysulfone-based polymer, 10 to 30% by weight of a hydrophilic pore-controlling agent, and a remaining amount of a solvent to form a film; A second step of forming pores in the surface layer of the film by air injection maintained at a temperature of 20 to 60 DEG C and a humidity of 30 to 85% And a third step of immersing the support in the coagulation bath after the above-mentioned step, thereby peeling the film from the support.

The solvent used in the polymer solution of the first step of the present invention is preferably at least one selected from the group consisting of N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide and dimethylacetamide.

The hydrophilic pore-controlling agent used in the polymer solution may be at least one additive selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and silica.

More preferably, the additives include glycols including ethylene glycol and glycerol; Alcohols including ethanol and methanol; And a ketone containing acetone. The hydrophilic additive is further mixed with the hydrophilic additive.

Since the polysulfone-based polymer as the main component of the polysulfone-based separator of the present invention has very stable characteristics due to the electrostatic attraction by the resonance electrons between the aromatic groups around the -SO ₂ group, the stability, chemical resistance, It can have various pore sizes and has excellent mechanical strength. Here, the preferred polysulfone-based polymer used may include singly or in a mixed form thereof selected from the group consisting of polysulfone, polyethersulfone and polyallyl ether sulfone polymer.

In the step (2) of the present invention, the immersion may be performed at a reaction temperature of 10 to 100 ° C for 30 minutes to 10 hours, and the sol-coating solution may be coated on the polyphosphoric acid separator.

If the reaction temperature is less than 10 ° C, the coating of the metal compound is not performed well. If the reaction temperature exceeds 100 ° C, the productivity is poor due to additional experimental equipment to be refluxed due to evaporation by aqueous solution boiling.

Next, the step (3) of drying the polysulfone-based membrane after the immersion is described.

After immersing the polysulfone-based membrane into the sol-coating solution, the reaction solution may be post-treated and dried by a conventional method. The drying temperature of the polysulfone-based membrane coated with the sol coating solution is preferably from room temperature to 80 ° C, more preferably from room temperature to gradually dry.

Further, according to a preferred embodiment of the present invention, when the sol-coating solution further contains a binder and an initiator, it may further include UV irradiation or heat treatment after the step (3).

Specifically, a binder and an initiator may be added to increase the adhesion between the coated nanoparticle metal oxide and the polysulfone-based separator, followed by curing by UV irradiation or heat treatment.

According to another aspect of the present invention, there is provided a polysulfone separator; And a coating layer containing a nano-metal formed on the polysulfone-based separation membrane.

The polysulfone-based separator of the present invention may be a polysulfone-based separator prepared by a conventional method as described above, and the method of manufacturing the polysulfone-based separator may be any method that can be manufactured by those skilled in the art. The thickness of the polysulfone-based membrane may be generally 50 to 200 μm, and the type of the membrane may include both a symmetric membrane and an asymmetric membrane, as well as a flat membrane or a hollow fiber membrane.

The nano metal may be aluminum, and the thickness of the nano metal-containing coating layer may be 40 to 500 nm. If the thickness of the coating layer is less than 40 nm, there is a problem that the microorganism removing effect is insufficient by the coating, and if it is more than 500 nm, there is a problem that the coating layer is separated due to the bonding force problem.

In addition, the coating layer containing nano-metal formed on the polysulfone-based separation membrane may further include a binder material, and most preferably, the binder material is selected from the group consisting of a silane coupling agent and an organic silicon compound Or more.

The polysulfone-based separator of the present invention may contain a polymer binder or Since the material remaining after the addition of the silane coupling agent is further contained, there is no significant difference in the initial microbial removal ability when the polymeric binder or the silane coupling agent is not contained, but the polymeric binder or the silane coupling agent is included in the late microbial removal rate It can be confirmed that the late microbial removal rate of the polyphosphoric acid type membrane retains the initial removal performance (see Table 1).

That is, by further including a binder, the ability to remove microorganisms can be maintained regardless of the duration, and the binder is derived from any one or more selected from the group consisting of a silane coupling agent and an organosilicon compound, Exhibit superior sustainability as a result of the use of silane coupling agents.

Accordingly, the polysulfone-based membrane of the present invention can remarkably improve the ability to remove microorganisms, and can provide a polysulfone-based membrane having excellent ability to remove microorganisms having a long-lasting ability to remove microorganisms and a polysulfone- can do.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

[ Example ]

Example  One

(1) Preparation of polysulfone-based membrane

14% by weight of polysulfone polymer was dissolved in 66% by weight of dimethylacetamide, 5% by weight of polyethylene glycol (molecular weight 200) and 15% by weight of polyvinylpyrrolidone were added and stirred for 12 hours or more to prepare a polymer solution. The polymer solution was uniformly coated on a stainless steel support at 10 占 폚 at a rate of 1.5 m / min so as to have a thickness of 110 占 퐉. Thereafter, the coated polymer solution was treated by exposure to air with a temperature range of 32 ° C and a humidity range of 85% to control the pores in the upper layer, and a mixed solution coagulation bath in which the composition ratio of isopropyl alcohol / water was kept constant And solidified. Thereafter, the membrane was peeled off from the support, the residual solvent component contained in the membrane was extracted in a water bath, and the membrane was dried with air at 80 ° C to prepare a membrane.

The prepared polysulfone separator had an average pore diameter of 1.1 탆, a maximum pore diameter of 1.3 탆, and a thickness of 110 탆, and the permeability was 78 ml / cm 2 * bar * min.

(2) Preparation of sol coating solution and coating on polysulfone type separator

20 g of aluminum isoprope oxide was added to 380 ml of distilled water and dispersed using a mechanical stirrer. At this time, the temperature was maintained at 95 캜 and stirred for 1 hour. Thereafter, 1 g of nitric acid was further added, followed by stirring for 3 hours to prepare an alumina sol coating solution. The prepared polysulfone membrane was immersed in the coating solution for 30 minutes to be coated, and then dried at 40 ° C to prepare an alumina-coated polysulfone membrane.

The prepared polysulfone membrane had an average pore diameter of 1.1 탆, a maximum pore diameter of 1.3 탆, and a thickness of 110 탆, and the permeability was 80 ml / cm 2 * bar * min.

Example  2

A sol coating solution was prepared in the same manner as in Example 1 except that 40 g of aluminum isoprofil oxide, 360 ml of distilled water and 2 g of nitric acid were used, and a polysulfone separation membrane was coated thereon.

The prepared polysulfone membrane had an average pore diameter of 1.0 탆, a maximum pore diameter of 1.3 탆, and a thickness of 115 탆, and the permeability was 77 ml / cm 2 * bar * min.

Example  3

Except that 2 g of methacryloxypropyltrimethoxysilane and 0.05 g of benzophenone were further added and the mixture was stirred for 2 hours to prepare a coating solution. In the same manner as in Example 1, a polysulfone-based separator was prepared Lt; / RTI >

The prepared polysulfone-based membrane was dried and UV-cured by UV irradiation (using H-lamp, UV energy: 2.37 J / cm 2).

The prepared polysulfone membrane had an average pore size of 0.96 mu m, a maximum pore size of 1.1 mu m, and a thickness of 112 mu m, and the permeability was 70 mL / cm2 * bar * min.

Example 4

A coating solution was prepared in the same manner as in Example 3 except that 40 g of aluminum isoprope oxide, 360 ml of distilled water and 2 g of nitric acid were used. The coating solution was coated, dried, and UV cured.

The prepared polysulfone membrane had an average pore size of 0.89 탆, a maximum pore size of 1.0 탆, and a thickness of 120 탆, and the permeability was 65 ml / cm 2 * bar * min.

Example 5

A coating solution was prepared in the same manner as in Example 3, except that polyvinylpyrrolidone was used instead of methacryloxypropyltrimethoxysilane. The polysulfone separator was coated, dried and UV-cured.

The prepared polysulfone membrane had an average pore size of 0.89 탆, a maximum pore size of 1.0 탆, and a thickness of 120 탆, and the permeability was 65 ml / cm 2 * bar * min.

Example 6

A coating solution was prepared in the same manner as in Example 3, except that a titaninium tetraisopropoxide oxide was used in place of the aluminum isoprofen oxide, and the polysulfone separator was coated, dried and UV-cured.

The prepared polysulfone membrane had an average pore size of 0.89 탆, a maximum pore size of 1.0 탆, and a thickness of 120 탆, and the permeability was 65 ml / cm 2 * bar * min.

Comparative Example  One

A polysulfone-based membrane was prepared in the same manner as in Example 1 except that it was not immersed in a sol coating solution.

Experimental Example  One

The porosity and average pore size of the membrane prepared in Examples 1 to 4 and Comparative Example 1 were measured using a membrane porosimeter (PMI, model: CFP-1200-AE) Evaluation unit (manufactured by Woongjin Chemical Co., Ltd.) - The unit area and the water permeability per minute were measured at a constant pressure (1 bar) through a sample holder having a diameter of 90 mm.

(MS2 phage) solution diluted to 8x10 ⁵ / ml in PFU / ml (PFU: plaque forming units) at a constant pressure of 1 bar through a sample holder having a diameter of 90 mm The microbial removal performance was evaluated by permeation.

At this time, the initial microbial removal rate is the result of analyzing the initial removal rate of the manufactured membrane, and the late microbial removal rate is the result of the measurement after 24 hours of water permeation.

division Al concentration
(%) bookbinder
(%) Average pore size
(탆) Amount of water Weight change
(wt%) Initial microbial removal rate
(%) Late microbial removal rate
(%) Example 1 5 0 1.1 80 13.8 95.2 62.0 Example 2 10 0 1.0 77 22.1 99.9 75.2 Example 3 5 0.5 0.96 70 14.9 99.9 99.9 Example 4 10 1.0 0.89 65 22.9 99.9 99.9 Example 5 5 0.5 0.89 65 17.2 99.9 85.2 Example 6 5 0.5 0.89 65 15.2 99.9 80.1 Comparative Example 1 0 0 1.1 78 0 0.8 0.7

As can be seen from Table 1, the microbial removal rate of the polysulfone-based membrane of Comparative Example 1 was found to be almost 0.8%. It was confirmed that the size of the microorganism to be removed (30 to 40 nm) was smaller than the average pore diameter of the polysulfone type membrane of 1.1 탆, so that it was not removed by size exclusion. On the other hand, in Examples 1 to 6, it was confirmed that 95% or more of the removal of the initial microorganisms was removed in the case of the polysulfone separator coated with alumina sol. This is a result of confirming the removal effect by adsorption of microorganisms by alumina. Also, as the content of the alumina precursor material in the alumina sol coating solution increases, the adsorption amount increases and the removal rate increases.

In Examples 1 to 6, it was confirmed that the initial removal performance was maintained at the late microbial removal rate according to the use of the silane coupling agent.

Claims (13)

(1) nanoparticle metal compounds; And a solvent;
(2) immersing the polysulfone-based separator in the sol-coating solution; And
(3) drying the polysulfone separator after the immersion; Wherein the polysulfone separation membrane has a high removal efficiency for microbes.
The method according to claim 1,
Wherein the nanoparticle metal compound in step (1) is an aluminum salt.
3. The method of claim 2,
The nanoparticle metal compound of step (1) may be at least one selected from the group consisting of aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), aluminum isoprope oxide (Al (O-CH (CH ₃ ) ₂ ) ₃ , alumina formate ) And aluminum nitroformacetate (" ANFA ").≪ / RTI >
The method of claim 3,
Wherein the nanoparticle metal compound in step (1) is an aluminum isoprope oxide (Al (O-CH (CH ₃ ) ₂ ) ₃ ).
The method according to claim 1,
Wherein the metal compound of step (1) comprises 1 to 15% by weight based on 100% by weight of the sol-coating solution.
The method according to claim 1,
Wherein the sol-coating solution of step (1) further comprises a binder material.
The method according to claim 6,
Wherein the binder is a silane coupling agent.
The method according to claim 6,
The method for producing a polysulfone-based membrane according to claim 1, further comprising the step of UV irradiation or heat treatment after the step (3).
Polysulfone type separator; And
Formed on the polysulfone-based separation membrane And a coating layer containing a nano metal. The polysulfone-based separator has excellent microbial removal ability.
10. The method of claim 9,
Wherein the coating layer further comprises a binder material.
11. The method of claim 10,
Wherein the binder material is selected from the group consisting of a silane coupling agent and an organosilicon compound
Characterized in that the microorganism is one or more selected from the group consisting of
Polysulfone type separator.
10. The method of claim 9,
Wherein the nano-metal is aluminum.
10. The method of claim 9,
Wherein the nano-metal-containing coating layer has a thickness of 40 to 500 nm.