KR20200061946A - A preparation method of a polar membrane comprising multiple polymer layers and a polar membrane prepared thereby - Google Patents

Abstract

The present invention relates to a method for manufacturing a polar membrane having nanopores by immersing a porous polymer support in a solution containing a first polymer and a solution containing a second polymer and immersing the same in a non-solvent to solidify the first polymer and/or the second polymer. The present invention also relates to a polar membrane manufactured thereby, and a use of the manufactured polar membrane. It is possible to significantly increase the particle removal rate.

Description

A preparation method of a polar membrane comprising multiple polymer layers and a polar membrane prepared thereby}

The present invention is to immerse the porous polymer support in a solution containing a first polymer and a solution containing a second polymer, and then immersing it in a non-solvent to solidify the first polymer and/or the second polymer, thereby forming a polar membrane having nanopores. It relates to a manufacturing method, a polar membrane produced thereby, and the use of the prepared polar membrane.

In the semiconductor process, it is increasingly important to remove small amounts of impurities contained in a photoresist solution that forms a pattern due to a reduction in line width. The impurities may be present as hard particles, which are metal particles, and gel particles or soft particles, which are agglomerates of polymers and metals. While membranes capable of removing hard particles are commercialized and used in the field, there are not many commercialized membranes that can be used for removing soft particles and performance is insufficient.

On the other hand, currently available commercially available membranes for soft particle removal are nylon-based membranes, which are mainly used for the purification of photoresist solutions, but it is known that removal of soft particles is not yet complete. This is because, in the membrane manufacturing process, even though the pores on the surface are nano-scale, there are limitations in that impurities in the photoresist solution cannot be sufficiently removed due to large internal pores.

Under this background, the present inventors have made great efforts to produce a membrane with high removal efficiency of soft particles, and as a result, when the membrane is prepared by forming a polymer layer by using the first polymer-containing solution and the second polymer-containing solution in double It has been discovered that the removal efficiency of soft particles can be greatly increased by efficiently filling or coating voids, and the present invention has been completed.

An object of the present invention is a first step of immersing a porous polymer support in a solution containing a first polymer having a polar functional group; A second step of immersing the porous polymer support in a solution containing a second polymer having a polar functional group; And a third step of solidifying the first polymer, the second polymer, or both by immersing the immersed porous polymer support in a non-solvent to provide a method for producing a polar membrane having nanopores Is to do.

Another object of the present invention is to provide a polar membrane produced thereby.

Another object of the present invention is to provide a fluid treatment device comprising the polar membrane.

Another object of the present invention is to provide a fluid treatment method, comprising passing a fluid through the polar membrane.

The detailed contents for carrying out the present invention are as follows. Meanwhile, each description and embodiment disclosed herein may be applied to each other description and embodiment. That is, all combinations of the various elements disclosed herein are within the scope of the present invention. In addition, it cannot be said that the scope of the present invention is limited by the specific descriptions described below.

In addition, one of ordinary skill in the art can recognize or identify a number of equivalents to certain aspects of the invention described in this application using only routine experimentation. In addition, such equivalents are intended to be included in the present invention.

As one aspect for achieving the above object, the present invention is a first step of immersing a porous polymer support in a solution containing a first polymer having a polar functional group; A second step of immersing the porous polymer support in a solution containing a second polymer having a polar functional group; And a third step of solidifying the first polymer, the second polymer, or both by immersing the immersed porous polymer support in a non-solvent to provide a method for producing a polar membrane having nanopores do.

Specifically, the porous polymer support of the present invention may be polar or non-polar, hydrophilic or hydrophobic, and specifically, non-polar or hydrophobic. More specifically, the porous polymer support is polyethylene, polypropylene, polyester, polycarbonate, polyurethane, polyamide, polysulfone (PSf), polyether sulfone (PES), poly(methyl methacrylate), polyvinylidene Fluoride (PVDF), polytetrafluoroetherene, or combinations thereof.

The porous polymer support includes pores (or voids) on the cross-section, surface, or both of the supports. The average size of pores of the support may be 0.01 μm or more, 0.02 μm or more, 0.02 μm or more, or 0.04 μm or more, and specifically 0.01 μm to 10 μm, 0.02 μm to 10 μm, 0.04 μm to 10 μm, and 0.04 μm to 5 Μm, 0.04 μm to 1 μm, or 0.04 μm to 0.5 μm, but is not limited thereto. On the other hand, if the average pore size of the porous polymer support is less than 0.04 μm, it may be difficult for the first polymer solution or the second polymer solution to be filled in the cross section of the support, and if it exceeds 10 μm, the first polymer solution or the second polymer solution is It may be lost from the cross section to the surface, so the efficiency of removing impurities may not be high.

Conventionally, a polyolefin-based membrane such as polyethylene and polypropylene has excellent chemical durability, but has a disadvantage in that the purification purity is not high when removing impurities including soft particles. For example, the soft particles are not easily removed by removing particles by using the pores of the membrane, so they must be removed in a way that the membrane and particles are adsorbed by the membrane in the process of contacting each other. Because it is non-polar or hydrophobic, it is difficult to remove by adsorption. On the other hand, the membrane of the present invention has excellent chemical durability and at the same time has a polarity on the surface, so that impurities including soft particles and the like can be easily removed.

In the present invention, the solution containing the first polymer and the solution containing the second polymer may mean a solution containing the first polymer or the second polymer, respectively. The solvent of both solutions is not particularly limited, but may be dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, formic acid, or a combination thereof. The solvent may be dimethylacetamide or formic acid. The solution containing the first polymer and the solution containing the second polymer are 1 to 35 wt%, 1.5 to 30 wt%, 2 to 25 wt% 2.5 to 20 wt%, or 3 to 1 wt% of the first or second polymer. 15% by weight.

Here, both the first polymer and the second polymer are polymers containing polar functional groups, and may have the same or different polar functional groups. By using a polymer having different polar functional groups, it is possible to efficiently reduce the pore size of the prepared membrane, as well as significantly improve the ability to adsorb soft particles. The present inventors have membranes prepared using a second polymer having a polar functional group different from the first polymer (Preparation Examples 1 to 5) are membranes made using the same second polymer as the first polymer (Preparation Examples 8 and 9). It was confirmed that it shows a significantly reduced pore size and a significantly increased soft particle removal rate compared to (Examples 1 and 2). Without being bound by a particular theory, it is understood that these results improve the soft particle removal rate by reducing the pore size of the first polymer and blending the second polymer with the first polymer.

The first polymer and the second polymer are specifically functional groups selected from the group consisting of -OH, -NHCO-, -CO-, -SO ₂ -, -SO-, -CONHCO-, -COO-, and -NHCOO- It may be to have different from each other. More specifically, the first polymer and the second polymer are cellulose acetate, sulfonated polymer, nylon, polysulfone, polyethersulfone, fluorine-based polymer, Teflon, ethylene vinyl alcohol copolymer (poly(vinyl alcohol-co-ethylene); EVAL) ), polyimide, polybenzimidazole, and aromatic polyamide. The aromatic polyamide may be meta-aramid, p-aramid, or a combination thereof, but is not limited thereto. The fluorine-based polymer may be polyvinylidene fluoride, but is not limited thereto. Specifically, the first polymer and the second polymer of the present invention may be a polymer having a polar functional group selected from the functional group consisting of -OH- and -NHCO-, but may also be an ethylene vinyl alcohol copolymer or nylon. Does not work.

The ethylene vinyl alcohol copolymer may be represented by the following formula, and may be a copolymer composed of vinyl alcohol having polarity and ethylene having non-polarity. The ethylene vinyl alcohol copolymer may have an ethylene mole% of 20% to 50%, but is not particularly limited thereto. However, in the case where the ethylene mol% (n) is 20 mol% or more and 50 mol% or less based on the total mol% (m + n), the ethylene vinyl alcohol copolymer exhibits appropriate polarity and interacts with a hydrophobic support to form a phase on the support. While being stably fixed to, the support can be sufficiently hydrophilized.

[Formula of ethylene vinyl alcohol copolymer]

The nylon of the present invention may be nylon 6, nylon 66, nylon 46, nylon 612, or a combination thereof, specifically nylon 46, but is not limited thereto. Nylon 46 may be represented by the following formula.

[Formula of Nylon 46]

When the first polymer and the second polymer are polymers having a polar functional group selected from the functional group consisting of, for example, -OH- and -NHCO-, hydrogen bonds are formed between the functional groups of the first polymer and the second polymer to form macroscopic pores. Since fine pores are formed, the removal rate of soft particles of the membrane can be greatly improved.

In addition, the manufacturing method of the present invention is not limited to immersing the porous polymer support in the first polymer-containing solution and the second polymer-containing solution, and after immersing in the second polymer-containing solution, a third polymer-containing solution such as a third polymer-containing solution It may further include a step of immersing in. At this time, the third polymer and the like are as described above for the first polymer and the second polymer.

In the present invention, a non-solvent is a solvent that does not dissolve or swell the polymer to the melting point of the polymer or the boiling point of the liquid, and may be water, alcohol, glycol, or a combination thereof, and the glycol is ethylene glycol. Can be. In addition, the non-solvent is mixed with at least one selected from the group consisting of dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide with at least one selected from the group consisting of water, alcohol, and glycol. It can be a non-sale. Specifically, the non-solvent may include water. The non-solvent of the present invention can induce solidification of the first polymer or the second polymer contained in the first polymer-containing solution or the second polymer-containing solution by a phase inversion process.

Here, the phase conversion method is a process of inducing solidification of the polymer by exchanging solvents and non-solvents to produce a membrane. First, after forming a film on a support using a polymer solution, immersing the film-formed support in a non-solvent causes the composition of the polymer solution to change due to the mutual diffusion of the solvent and the solvent and the non-solvent. As the solidification phenomenon occurs, a polymer film having a high porosity is formed according to the substitution rate of the solvent and the non-solvent. In the present invention, the first polymer or the second polymer can be solidified by a phase conversion method, and thus the solidified first polymer or second polymer has a high porosity. On the other hand, the soft particles can be removed by adsorption by the membrane, and the polymer layer formed by the phase conversion method has a high porosity, but also has a lot of opportunities to contact particles such as soft particles due to the mutual bonding force with the polymer. Therefore, the particle removal rate can be extremely improved.

The solidified first polymer or the second polymer may fill the inside of the pores present on the surface or the cross-section of the support, or may be provided as a discontinuous layer on the pore surface. For example, the first polymer or the second polymer may be provided inside the pores of the support to reduce the volume of the pores. In addition, the first polymer or the second polymer may be solidified to partially or completely coat the surface of the pores of the support. Therefore, the solidified first polymer or the second polymer can stably reduce the size of pores present on the surface and/or cross section of the support, and has a high porosity as it is formed in the phase conversion method, such as soft particles. Since the opportunity to contact the particles can be increased, it is possible to improve the efficiency of removing impurities in the membrane.

In the manufacturing method of the present invention, a first step of immersing the porous polymer support in a solution containing a first polymer having a polar functional group, and a immersing the porous polymer support in a solution containing a second polymer having a polar functional group The second step may be performed continuously so as not to include the step of solidifying the first polymer by immersing the support in a non-solvent between the two steps. In the case of the membranes prepared through the step of solidifying the first polymer by immersing the support in a non-solvent before immersing the support in the second polymer-containing solution (Preparation Examples 6 and 7), the membrane prepared without the above steps (production In addition to having a smaller pore size than Examples 1 to 5), it was confirmed that the soft particle removal rate was higher (Examples 1 and 2).

Without being bound by a particular theory, the membrane prepared by solidifying the polymer by immersing the support in a non-solvent between the first and second stages as described above is the first polymer and the first polymer as the solidification of the first polymer 2 It shows a significantly reduced bonding strength between polymers due to interaction with polymers (eg, hydrogen bonds). On the contrary, the membrane prepared in a solution state without immersing the support in a non-solvent between the first and second stages has a significantly increased binding force between the first polymer and the second polymer, and the polymer and polymer chains are increased by the increased binding force. It has micropores in addition to the large pores, and by these micropores, it is possible to make contact with particles such as soft particles with high probability. Since the micropores are not large pores that greatly contribute to the adsorption capacity of nanoparticles such as soft particle nanoparticles, membranes manufactured without a solidification step between the first and second steps have a high particle removal rate due to high particle adsorption capacity. Can represent

In another aspect, the present invention provides a polar membrane having nano pores produced by the above-described manufacturing method. The polar membrane of the present invention has a porous polymer support, a first polymer layer impregnated inside the pores present on the surface and/or the cross section of the support, or a solidified first polymer layer coating the surface of the pores, on the first polymer layer It may have a structure comprising a solidified second polymer layer or a solidified second polymer layer impregnated in the interior of the pores of the support that is not covered by the first polymer layer or coating the surface thereof.

In the membrane of the present invention, the first polymer layer and the second polymer layer may be a polymer-containing solution immersed in a non-solvent and solidified by a phase conversion method, and the pore size of the membrane is effectively formed by forming a polymer layer in duplicate. At the same time, while having a high porosity by the phase conversion method, the chance of contact with impurity particles such as soft particles is significantly increased due to the mutual bonding force with the polymer, and thus has an improved soft particle adsorption ability, thereby reducing the removal rate of the soft particles of the membrane. Can be significantly increased.

According to one non-limiting example of the present application, the membrane on which the first polymer layer and the second polymer layer are formed is 3% to 50% of the pore size of the porous polymer support before the first polymer layer and the second polymer layer are formed. It was confirmed that the pore size was reduced. In particular, the membrane prepared without immersion in a non-solvent between the step of immersing the support in the first polymer-containing solution and the step of immersing in the second polymer-containing solution was reduced to 40% or less of the pore size of the support, and further, It was confirmed that the pore size of the membrane prepared using different types of first and second polymers was reduced to 15% or less.

In addition, the polar membrane having nano-pores of the present invention has a pore size of 0.1 nm to 100 nm, 0.1 nm to 80 nm, 0.1 nm to 60 nm, 0.1 nm to 40 nm, 0.1 nm to 20 nm, or 0.5 nm to 20 nm, specifically 1 nm to 20 nm, 1 nm to 15 nm, 1 nm to 14 nm, 1 nm to 13 nm, 1 nm to 12 nm, 1 nm to 11 nm, or 1 nm to 10 nm, It is not limited to this.

The polar membrane having the nano-pores of the present invention has a pore size of 1% to 50%, 1% to 45%, 1% to 40%, 1% to 30%, 1% to 1% to 50% compared to the pore size of the porous polymer support used. 25%, 1% to 20%, 1% to 15%, or 3% to 15%, but is not limited thereto.

The polar membrane having nano-pores of the present invention adsorbs particles such as soft particles to improve impurity removal rate as the polarity is imparted by a polymer having a polar functional group, and small pore size as it includes a double-formed polymer layer. With improved particle adsorption capacity, it has an excellent effect of significantly increasing the soft particle removal rate.

Polar membranes having nanopores of the present invention may have a soft particle removal rate of 83% to 99.99%, 85% to 99.99%, 87% to 99.99%, 89% to 99.99%, or 90% to 99.99%, but are not limited thereto. Does not work.

According to one non-limiting example of the present application, it was confirmed that the membrane formed with the first polymer layer and the second polymer layer has a soft particle removal rate of 83% or more. In particular, the membrane prepared without immersion in a non-solvent between the step of immersing the support in the first polymer-containing solution and the step of immersing in the second polymer-containing solution has a soft particle removal rate of 85% or more, and additionally, It was confirmed that the membrane prepared using the first polymer and the second polymer had a soft particle removal rate of 90% or more. It is understood that, as described above, a strong interaction such as hydrogen bonding occurs between the first polymer layer and the second polymer layer formed on the membrane to form fine pores, thereby increasing the particle adsorption capacity of the membrane and improving particle removal rate.

In another aspect, the present invention provides a fluid processing apparatus including a polar membrane having the nanopores described above. The fluid treatment device may be a wastewater treatment device or an ultrapure water purification device of a semiconductor process, a general water treatment device, a wastewater treatment device, a solvent recovery device, a device for recovering useful substances contained in a solvent, and a pretreatment of a seawater desalination process It may be a device, but is not limited thereto.

In addition, the present invention provides a fluid treatment method comprising passing a fluid through a polar membrane having the nano-pores described above. Here, the fluid may be ultrapure water, wastewater, or seawater, and may be a solvent other than water, but is not limited thereto.

The manufacturing method of the present invention is to fill the inside of the porous polymer support surface and the pores existing therein with a polymer having polarity or to coat the surface of the pores to form a polymer layer in double, soaked in a non-solvent in a polymer solution. It is possible to provide a membrane capable of greatly increasing the particle removal rate by reducing the size of pores and improving the polarity.

Hereinafter, the configuration and effects of the present invention will be described in more detail through the production examples, but these production examples are only illustrative examples of the present invention and the scope of the present invention is not limited to these production examples.

Preparation Example 1: Preparation of EVOH and nylon membrane

To prepare a membrane having a polymer layer double formed on a polyethylene support having an average pore size of 0.04 µm, 5% by weight of ethylene acetyl vinyl alcohol copolymer (poly(ethylene-co-vinyl alcohol); EVOH, ethylene 32 mol%) A polymer solution dissolved in 95% by weight of amide was prepared, and a polyethylene support was immersed in the solution. After immersion for 1 minute, the excess solution was uniformly applied with a roller. Thereafter, the support was immersed in a polymer solution in which 5% by weight of nylon 46 was dissolved in 95% by weight of formic acid (formic acid) for 1 minute, and the solution buried in excess with a roller was uniformly applied. After the support immersed in the two polymer solutions was immersed in water at 20° C. to solidify the polymer, the solvent was removed to prepare a membrane. As a result of evaluating the prepared physical properties, it was confirmed that the prepared membrane had an average pore size of 0.005 μm.

Preparation Example 2: Preparation of EVOH and nylon membrane

A membrane was prepared in the same manner as in Preparation Example 1, except that a polyethylene support having an average pore size of 0.1 μm was used, and the average pore size of the prepared membrane was found to be 0.007 μm.

Preparation Example 3: Preparation of EVOH and nylon membrane

A membrane was prepared in the same manner as in Preparation Example 1, except that a polyethylene support having an average pore size of 5 μm was used, and the average pore size of the prepared membrane was found to be 0.015 μm.

Preparation Example 4: EVOH and nylon membrane production

A membrane was prepared in the same manner as in Preparation Example 1, except that 10% by weight of EVOH was used, and the average pore size of the prepared membrane was found to be 0.003 μm.

Preparation Example 5: EVOH and nylon membrane production

A membrane was prepared in the same manner as in Preparation Example 1, except that 10% by weight of nylon was used, and the average pore size of the prepared membrane was found to be 0.001 μm.

Preparation Example 6: Preparation of EVOH and nylon membrane

To prepare a membrane having two polymer layers formed on a polyethylene support having an average pore size of 0.04 μm, a polymer solution in which 5 wt% of EVOH (32 mol% ethylene) was dissolved in 95 wt% of dimethylacetamide was prepared, and this solution The polyethylene support was immersed. After immersing for 1 minute, the excess solution was uniformly applied with a roller, the support was immersed in water at 20° C. to solidify the polymer solution, and then the solvent was removed to prepare a primary membrane. After drying the prepared primary membrane, the primary membrane was immersed for 1 minute in a polymer solution in which 5% by weight of nylon 46 was dissolved in 95% by weight of formic acid, and the excess solution was uniformly applied with a roller.

Thereafter, the primary membrane was immersed in water at 20°C to solidify the polymer, and then the solvent was removed to prepare a secondary membrane. As a result of evaluating the physical properties of the prepared secondary membrane, it was confirmed that the average pore size of the prepared secondary membrane was 0.015 μm.

Preparation Example 7: Preparation of EVOH and nylon membrane

To prepare a membrane formed with two polymer layers on a polyethylene support having an average pore size of 0.04 μm, the support was immersed in a polymer solution in which 5% by weight of nylon 46 was dissolved in 95% by weight of formic acid. After immersion for 1 minute, the excess solution was uniformly applied with a roller. Thereafter, the support was immersed in water at 20°C to solidify the polymer, and then the solvent was removed to prepare a primary membrane.

After drying the prepared primary membrane, 5% by weight of EVOH (32 mol% of ethylene) was immersed in a polymer solution dissolved in 95% by weight of dimethylacetamide for 1 minute, and the solution buried in excess with a roller was uniformly applied. Thereafter, the support was immersed in water at 20°C to solidify the polymer, and then the solvent was removed to prepare a secondary membrane. As a result of evaluating the physical properties of the prepared secondary membrane, it was confirmed that the average pore size of the prepared secondary membrane was 0.02 μm.

Preparation Example 8: Preparation of EVOH membrane

A polymer solution in which 5% by weight of EVOH was dissolved in 95% by weight of dimethylacetamide was prepared on a polyethylene support having an average pore size of 0.04 μm, and the support was immersed in this solution. Once again, 5% by weight of the EVOH polymer solution was immersed for 1 minute, and then the excess solution was uniformly applied with a roller. Thereafter, the support was immersed in water at 20°C to solidify the polymer, and then the solvent was removed to prepare a membrane. As a result of evaluating the physical properties of the prepared membrane, it was confirmed that the average pore size of the prepared membrane was 0.01 μm.

Preparation Example 9: Preparation of nylon membrane

On a polyethylene support having an average pore size of 0.04 μm, the support was immersed in a polymer solution in which 5% by weight of nylon 46 was dissolved in 95% by weight of formic acid. Once again, after immersing the nylon 46 5% by weight polymer solution for 1 minute, the excess solution was uniformly applied with a roller. Thereafter, the support was immersed in water at 20°C to solidify the polymer, and then the solvent was removed to prepare a membrane. As a result of evaluating the physical properties of the prepared membrane, it was confirmed that the average pore size of the prepared membrane was 0.015 μm.

Preparation Example 10: EVOH and nylon membrane production

A polymer solution in which 5% by weight of EVOH was dissolved in 95% by weight of dimethylacetamide was prepared on a polyethylene support having an average pore size of 0.04 μm, and the support was immersed in this solution. After immersion for 1 minute, the excess solution was uniformly applied with a roller. Thereafter, the support was immersed in water at 20°C to solidify the polymer, and then the solvent was removed to prepare a membrane. As a result of evaluating the physical properties of the prepared membrane, it was confirmed that the average pore size of the prepared membrane was 0.03 μm.

Production Example 11: Preparation of nylon membrane

On a polyethylene support having an average pore size of 0.04 μm, the support was immersed in a polymer solution in which 5% by weight of nylon 46 was dissolved in 95% by weight of formic acid. After immersion for 1 minute, the support was immersed in this solution. After immersion for 1 minute, the excess solution was uniformly applied with a roller. Thereafter, the support was immersed in water at 20°C to solidify the polymer, and then the solvent was removed to prepare a membrane. As a result of evaluating the physical properties of the prepared membrane, it was confirmed that the average pore size of the prepared membrane was 0.02 μm.

Experimental Example 1: Measurement of the pore size of the membrane

The average pore size of the membrane prepared in the Preparation Example was measured using a Permporometer (Table 1).

Manufacturing example number Support
Average pore size Membrane
Average pore size One 40 nm 5 nm 2 100 nm 7 nm 3 500 nm 15 nm 4 40 nm 3 nm 5 40 nm 1 nm 6 40 nm 15 nm 7 40 nm 20 nm 8 40 nm 10 nm 9 40 nm 15 nm 10 40 nm 30 nm 11 40 nm 20 nm

Through Table 1, a porous polymer support is used as a porous polymer support having a macropore having an average pore size of 0.04 µm or more, and a membrane in which EVOH or nylon polymer is impregnated on the surface and the cross section alone (Preparation Example 10 and Preparation Example 11) Compared to that, it was confirmed that the pore size of the membranes (Preparation Examples 1 to 9) prepared by forming the polymer layer in multiple layers was significantly reduced. In addition, it can be seen that Preparation Examples 2 and 3 in which the average size of the support was 100 nm and 500 nm, respectively, also had a significantly reduced pore size by the solidified first polymer and/or second polymer.

Among membranes prepared by multi-coating, membranes formed using two types of polymers having different polar functional groups (Preparations 1, 4, and 5) are compared with membranes formed using the same polymer (Preparations 8 and 9). When it was confirmed that it has a significantly reduced pore size.

Moreover, when immersed in a solution containing the first polymer and then immersed in a non-solvent to form a membrane primarily and then immersed in a solution containing the second polymer (Preparations 6 and 7), the solution containing the first polymer And it was confirmed that the membranes (Preparations 1, 4, and 5) formed by immersing in a second polymer-containing solution continuously and then immersing in a non-solvent have a significantly reduced pore size.

Experimental Example 2: Evaluation of membrane removal rate of soft particles

The soft particle removal rate of the membrane prepared in Preparation Example was evaluated using palladium nanoparticles (average particle size, 3.5 nm) as soft particles (Table 2). The inductively coupled plasma (ICP) was used to measure the concentration of palladium in the stock solution before permeating the membrane and the permeate after permeating the membrane, and the soft particle removal rate of the membrane was calculated using the following equation.

Removal rate (%) = ((Palladium concentration of stock solution-Palladium concentration of permeate)/(Palladium concentration of stock)) * 100

Manufacturing example number Removal rate One 98.5% 2 97.8% 3 91% 4 99.3% 5 99.8% 6 89% 7 85% 8 91% 9 88% 10 71% 11 82%

Through this, it was confirmed that the membranes produced by forming the polymer layer in multiple layers (Production Examples 1 to 9) had significantly higher soft particle removal rates than the membranes prepared by forming the polymer layer singly (Production Examples 10 and 11).

In addition, among the membranes formed by forming a plurality of polymer layers, membranes formed using two kinds of polymers having different polar functional groups (manufacturing examples 1 to 5) are membranes formed using the same polymer (manufacturing examples 8 and 9). It showed a better soft particle removal rate.

Moreover, when compared with membranes formed by immersing in a solution containing a second polymer after the formation of the primary membrane (Preparation Example 6 and Preparation Example 7), the solution is immersed in a non-solvent between the steps of immersing in the first polymer-containing solution and the second polymer-containing solution. It was confirmed that the membranes formed by continuously immersing the two solutions without immersion (Preparations 1 to 5) showed excellent soft particle removal rates.

From the above description, those skilled in the art to which the present invention pertains will appreciate that the present invention may be implemented in other specific forms without changing its technical spirit or essential characteristics. In this regard, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention should be construed as including all changes or modifications derived from the meaning and scope of the following claims rather than the detailed description and equivalent concepts thereof.

Claims (12)

A first step of immersing the porous polymer support in a solution containing a first polymer having a polar functional group;
A second step of immersing the porous polymer support in a solution containing a second polymer having a polar functional group; And
A third method of solidifying the first polymer, the second polymer, or both by immersing the immersed porous polymer support in a non-solvent, thereby producing a polar membrane having nanopores.
The method of claim 1, wherein the porous polymer support has an average pore size of 0.04 μm to 10.0 μm.
The method of claim 1, wherein the second polymer comprises a polar functional group different from the polar functional group of the first polymer.
The functional group of claim 3, wherein the first polymer and the second polymer are -OH, -NHCO-, -CO-, -SO ₂ -, -SO-, -CONHCO-, -COO-, and -NHCOO-. Wherein each has a different functional group selected from the group.
The method of claim 1, wherein the solution containing the first polymer and the solution containing the second polymer are cellulose acetate, nylon, ethylene vinyl alcohol copolymer (poly(vinyl alcohol-co-ethylene); EVAL), aromatic polyamide , Polysulfone, polyethersulfone, polyvinylidenefluoride, polyimide, and polybenzimidazole.
The method of claim 1, wherein the method does not include immersing the support in a non-solvent between the first and second steps.
The method according to claim 1, wherein the solvent of the polymer solution is dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, formic acid, or a combination thereof.
The method of claim 1, wherein the non-solvent is one or more selected from the group consisting of water, alcohol, and glycol; Or a mixture of one or more selected from the group consisting of water, alcohol, and glycol and one or more selected from the group consisting of dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. , Way.
A polar membrane having nanopores, produced by the method of claim 1.
10. The membrane of claim 9, having a pore size of 0.001 to 0.02 μm.
A fluid handling device comprising the membrane of claim 9.
A method of treating fluid, comprising passing a fluid through the membrane of claim 9.