Method for manufacturing water treatment separation membrane using eco-friendly material for simultaneously performing manufacturing and modification, and water treatment separation membrane manufactured thereby

Abstract

The present invention relates to a method for manufacturing a water treatment separation membrane, the method comprising: a solution preparation step for preparing a modification solution; and a maintenance step in which a film form prepared by casting a polymer resin-containing polymer solution is maintained in the modification solution for one hour to manufacture a water treatment separation membrane, wherein the modification solution contains a base solvent, a pyrogallol compound containing a pyrogallol functional group, and a naturally derived amine material.

Description

A method for manufacturing a water treatment separation membrane using eco-friendly materials, in which manufacturing and modification are performed simultaneously, and a water treatment separation membrane manufactured thereby

[0001] The present invention relates to a method for manufacturing a water treatment separation membrane using an eco-friendly material, in which manufacturing and modification are performed simultaneously, and to a water treatment separation membrane manufactured thereby. More specifically, the present invention relates to a method for manufacturing a water treatment separation membrane using a naturally derived material and having improved fouling resistance and permeability without a separate additional process, and to a water treatment separation membrane manufactured thereby.

[0002] Recently, environmental pollution, climate change, population growth, and industrial development have led to serious water pollution, leading to the emergence of diseases and drinking water shortages. To purify this polluted water, various technologies, including sedimentation, adsorption, disinfection, oxidation, and membrane filtration, are being developed. Among these, membrane filtration technology is attracting significant attention due to its advantages of high separation performance, ease of operation, and low energy requirements.

[0003] These membranes are divided into microfiltration (MF) membranes and ultrafiltration (UF) membranes depending on the size of the contaminants that can be removed and the level of separation, and are mainly manufactured from polymer materials such as poly(vinylidene fluoride) (PVDF), poly(ether sulfone) (PES), poly sulfone, polyethylene (PE), and polytetrafluoroethylene (PTFE) that have excellent mechanical strength and chemical durability.

[0004] However, these polymer materials are highly hydrophobic, resulting in low water permeability and limited applications. Furthermore, most organic contaminants readily adhere to the surface of these hydrophobic polymer materials through hydrophobic interactions, causing serious membrane fouling. These limitations lower membrane separation efficiency, increase maintenance costs, and shorten its lifespan. Therefore, extensive research is being conducted on water treatment membranes that exhibit high fouling resistance, superior separation performance, and applicability in a variety of environments.

[0005] (Prior patent) Republic of Korea Patent Publication No. 2011-0064520 (June 15, 2011)

[0006] The purpose of the present invention is to provide a method for manufacturing a water treatment separation membrane having improved fouling resistance and separation performance for organic substances using natural materials, and a water treatment separation membrane manufactured thereby.

[0007] In addition, another object of the present invention is to provide a method for manufacturing a water treatment separation membrane, which makes a hydrophobic polymer separation membrane hydrophilic through a simple process, enables mass production of the separation membrane, and improves process efficiency, and a water treatment separation membrane manufactured thereby.

[0008] According to one aspect of the present invention, embodiments of the present invention include a method for manufacturing a water treatment separation membrane, and a water treatment separation membrane manufactured thereby.

[0009] In one embodiment, the method for manufacturing the water treatment separation membrane includes a solution preparation step of preparing a modification solution; and a maintenance step of casting a polymer solution including a polymer resin and maintaining the prepared film form in the modification solution for a first time to manufacture the water treatment separation membrane; wherein the modification solution includes a base solvent, a pyrogallol compound including a pyrogallol functional group, and a naturally occurring amine substance.

[0010] In one embodiment, the modified solution may have a pH of 7.1 or higher, and the first time may be from 0.05 hours to 24 hours.

[0011] In one embodiment, in the solution preparation step, the modified solution further includes an oxidizing agent, and the pyrogallol compound may be 0.001 wt% to 25 wt%, the amine material may be 0.001 wt% to 25 wt%, and the oxidizing agent may be 0.001 wt% to 15 wt%.

[0012] In one embodiment, the natural amine substance includes at least one of taurine, lysine, arginine, serotonin, mescaline, thiamine, pyridoxamine, cysteine, alliin, α-poly-lysine, ε-poly-lysine, poly-arginine, poly-histidine, poly-asparagine, poly-glutamine, poly-tryptophan, albumin, casein, chitosan, collagen, and gelatin, and the pyrogallol compound includes at least one of pyrogallol, gallic acid, and propyl. Propyl gallate, syringic acid, catechin, catechol, methoxycatechol, benserazide, quercetin, tannic acid, phytic acid, ellagic acid, myricetin, fisetin, morin, kaempferol, rhamnetin, isorhamnetin, chrysin, luteolin, apigenin, baicalein, taxifolin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin At least one of epigallocatechin gallate and caffeic acid,The base solvent may include at least one of tris-acetate-EDTA buffer (TAE buffer), tris-boric acid-EDTA buffer (TBE buffer), phosphate buffer saline (PBS buffer), Tris-HCl buffer, and sodium hydroxide (NaOH) aqueous solution, and the oxidizing agent may include at least one of sodium periodate (NaIO4), lead tetraacetate (Pb(OAc)4), and potassium perruthenate (KRuO4).

[0013] In one embodiment, the maintaining step further includes dissolving the polymer resin in an organic solvent to prepare a polymer solution, and after casting the polymer solution, maintaining it in a reaction vessel containing a modification solution so that manufacturing and modification in a film form can be performed simultaneously by a non-solvent induced phase separation (NIPS) method.

[0014] In one embodiment, the polymer solution is prepared by dissolving a polymer resin in an organic solvent, and the polymer resin is selected from the group consisting of polyethersulfone, polyacrylonitrile, polyvinylpyrrolidone, polyethylene, polypropylene, polysulfone, polyacetylene, polyisobutylene, polyvinylchloride, polytetrafluoroethylene, polyphenylene sulfide, polystyrene, polydimethylsiloxane, polyvinylfluoride, polybenzimidazole, polyetherimide, polyvinylidene fluoride, and polyetheretherketone. Including at least one of the following, wherein the organic solvent may include at least one of dimethyl sulfoxide, dimethylformamide, methylpyrrolidone (1-methyl-2-pyrrolidone), and dimethylacetamide.

[0015] In one embodiment, in the polymer solution, the content of the polymer resin may be 2 wt% to 40 wt%.

[0016] In one embodiment, the polymer solution further comprises 0.1 wt% to 50 wt% of a pore-forming agent based on the total weight of the polymer solution, and the pore-forming agent may include at least one of polyvinyl pyrrolidone, polyethylene glycol, lithium chloride, calcium chloride, iron chloride, zinc chloride, sodium bicarbonate, polyethylene oxide, propionic acid, and acetic acid.

[0017] In one embodiment, in the maintenance step, the pyrogallol compound and the natural amine material can form at least one of the following chemical formulas 1 and 2 through at least one of a Michael addition reaction and a Schiff-base reaction.

[0018] (Chemical formula 1) , (chemical formula 2)

[0019] In one embodiment, at least one of the chemical formulas 1 and 2 may be provided on the inside or surface of the water treatment separation membrane.

[0020] In one embodiment, a water treatment separation membrane manufactured by the method described above may have an average pore diameter of 1 nm to 100 μm, a porosity of 1% to 90%, and a thickness of 1 μm to 1000 μm.

[0021] In one embodiment, the water treatment separation membrane is made of a polymer resin, wherein the polymer resin is at least one selected from the group consisting of polyethersulfone, polyacrylonitrile, polyvinylpyrrolidone, polyethylene, polypropylene, polysulfone, polyacetylene, polyisobutylene, polyvinylchloride, polytetrafluoroethylene, polyphenylene sulfide, polystyrene, polydimethylsiloxane, polyvinylfluoride, polybenzimidazole, polyetherimide, polyvinylidene fluoride, and polyetheretherketone. Including, the water treatment separation membrane may include at least one of the chemical formulas 1 and 2.

[0022] According to the present invention as described above, a method for manufacturing a water treatment separation membrane, which can efficiently manufacture a water treatment separation membrane using a natural material in an environmentally friendly and relatively simple manner, and a water treatment separation membrane manufactured thereby can be provided.

[0023] In addition, according to the present invention, a method for manufacturing a water treatment separation membrane with improved process efficiency by simultaneously modifying the water treatment separation membrane while manufacturing the water treatment separation membrane using a polymer resin can be provided, and a water treatment separation membrane manufactured thereby can be provided.

[0024] FIG. 1 is a drawing schematically showing a method for manufacturing a water treatment separation membrane according to one embodiment of the present invention.

[0025] Figure 2 is a photograph of the surface color of the separation membrane according to Comparative Example and Examples 1 to 4, and an SEM image confirming the surface and cross-sectional structure.

[0026] Figure 3 is a confocal scanning microscope image of the membrane according to Comparative Example and Examples 1 to 4 after exposure to a fluorescent protein solution.

[0027] Figure 4 shows the results of evaluating the fouling resistance (decrease in permeability over time) of organic matter (BSA) under the flow conditions of the membrane according to comparative examples and examples 1 to 4.

[0028] Specific details of other embodiments are included in the detailed description and drawings.

[0029] The advantages and features of the present invention, and the methods for achieving them, will become clear with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and unless otherwise specified in the following description, all numbers, values, and / or expressions expressing components, reaction conditions, and contents of components in the present invention are to be understood as being modified in all cases by the term "about" because such numbers are approximations that reflect various uncertainties of measurement that occur in obtaining such values, among other things. In addition, when a numerical range is disclosed herein, such range is continuous and includes every value from the minimum value to the maximum value inclusive, unless otherwise indicated. Furthermore, when such a range refers to an integer, every integer from the minimum value to the maximum value inclusive, unless otherwise indicated, is included.

[0030] Additionally, when a range is described for a variable in the present invention, it will be understood that the variable includes all values ​​within the described range including the described endpoints of the range. For example, the range "5 to 10" will be understood to include the values ​​5, 6, 7, 8, 9, and 10, as well as any subranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., and also any value between integers that fall within the described range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, and 6.5 to 9. For example, a range of "10% to 30%" would be understood to include values ​​such as 10%, 11%, 12%, 13%, etc., and all integers up to and including 30%, as well as any subranges such as 10% to 15%, 12% to 18%, 20% to 30%, and any value between reasonable integers within the stated range, such as 10.5%, 15.5%, 25.5%, etc.

[0031] FIG. 1 is a drawing schematically showing a method for manufacturing a water treatment separation membrane according to one embodiment of the present invention.

[0032] Referring to FIG. 1, a method for manufacturing a water treatment separation membrane according to one embodiment of the present invention can impart hydrophilic properties by modifying a water treatment separation membrane in situ or ex situ using a modification solution.

[0033] The method for manufacturing the above water treatment separation membrane may include a solution preparation step of preparing a modification solution; and a maintenance step of casting a polymer solution including a polymer resin and maintaining the prepared film form in the modification solution for a first time to manufacture the water treatment separation membrane. The modification solution may be composed of a base solvent, a pyrogallol compound including a pyrogallol functional group, and a naturally occurring amine substance.

[0034] Conventionally, conventionally used polymer membranes have high hydrophobicity, which limits their functionality and makes them susceptible to contamination during process operation. Therefore, there have been many attempts to make membranes hydrophilic, multifunctional, and secure durability against contamination.

[0035] Methods for hydrophilizing membranes can be broadly divided into an ex situ method, which modifies an already manufactured membrane, and an in situ method, which simultaneously manufactures and modifies the membrane.

[0036] Ex situ modification primarily involves coating or grafting hydrophilic or amphiphilic substances onto the surface of a porous membrane. While this ex situ method can hydrophilize membranes, it can also increase mass transfer resistance and reduce water permeability, depending on the membrane's pore size. Furthermore, it is difficult to effectively coat the interior of the membrane.

[0037] In situ modification is a method that simultaneously forms and modifies a membrane. Typically, hydrophilic or amphiphilic substances are mixed into a polymer casting solution, inducing phase separation and the partial insertion of the modifying substance into the membrane. While this method offers the advantages of simplicity and efficiency, the process of manufacturing a membrane through phase separation can alter the pore formation mechanism, potentially deforming the membrane structure and reducing its performance.

[0038] Furthermore, most of the modifying agents used to hydrophilize conventional membranes are synthetic chemicals, potentially posing a risk of harm to humans and the environment. Furthermore, membrane hydrophilization strategies utilizing various natural substances have limited potential to replace existing synthetic chemical modification strategies due to low modification efficiency or the prohibitive cost of these modifying agents.

[0039] The method for manufacturing a water treatment separation membrane according to an embodiment of the present invention can effectively modify a separation membrane while ensuring economic feasibility in an environmentally friendly manner by using a new natural material and in a simple manner.

[0040] The method for manufacturing a water treatment separation membrane according to the present embodiment may include a solution preparation step of preparing the above-described modification solution, and a maintenance step of adding a film form prepared by casting a polymer solution including a polymer resin to the above-described modification solution and maintaining the film form. The solution preparation step may be performed by preparing the modification solution and then adding the modification solution to a reaction vessel. The method for manufacturing the water treatment separation membrane may modify the membrane using the modification solution by an ex situ modification method or an in situ modification method. Specifically, the method for manufacturing the water treatment separation membrane according to the present embodiment may modify the membrane by an in situ modification method.

[0041] When applying the above ex situ modification method, the maintenance step can be performed by adding a pre-manufactured separation membrane through phase transfer to the modification solution and maintaining it at room temperature.

[0042] When applying the above in situ modification method, the maintaining step may further include dissolving the polymer resin in an organic solvent to prepare a polymer solution. After casting the polymer solution, the cast film form is maintained in a reaction vessel containing the modification solution, so that production and modification in the film form can be performed simultaneously by a non-solvent induced phase separation (NIPS) method. The polymer solution is manufactured in the form of a film through casting, and the cast film is manufactured in the form of a porous membrane using a non-solvent induced phase separation method in which the non-solvent induced phase separation method is used to support the non-solvent phase. When using the above in situ modification method, the polymer solution film form is maintained in a reaction vessel containing the modification solution, so that formation and modification of the membrane can be performed simultaneously. The modification material may be added to the polymer solution that is the material of the membrane, or may be added to the non-solvent, and preferably may be added to the non-solvent.

[0043] The non-solvent-induced phase separation method may include a phase separation process that occurs when the polymer solution is cast on a substrate such as glass and supported on a non-solvent. The non-solvent-induced phase separation method is a process in which the polymer solution comes into contact with a non-solvent, the organic solvent is extracted, and phase separation occurs, and utilizes the precipitation of the polymer by exchange of the organic solvent and the non-solvent within the polymer solution. A polymer resin is dissolved in the organic solvent to prepare a polymer solution, and the polymer solution is cast and precipitated in a reaction vessel equipped with a non-solvent, whereby the organic solvent within the polymer solution is extracted, the polymer is precipitated, and the organic solvent is removed to form pores within the film. The non-solvent is a solvent that cannot dissolve or swell the polymer resin, and may include water, alcohol, ether, hexane, and the like. When the in situ modification method is applied, the non-solvent may be used in the reaction vessel. In addition, the polymer solution film form can have pores formed by the non-solvent-induced phase separation method, and at the same time, the surface can be modified by the modification solution contained in the reaction vessel.

[0044] The above modified solution comprises a base solvent, a pyrogallol compound, and a naturally occurring amine substance, and the modified solution may have a pH of 7.1 or higher. The pH of the modified solution is within the aforementioned range, thereby effectively oxidizing the pyrogallol compound and enhancing its reactivity with the naturally occurring amine substance. Specifically, the pH of the modified solution may be 8 to 12, or 8 to 11, or 8 to 9.

[0045] The above pyrogallol compounds are natural substances, including pyrogallol, gallic acid, propyl gallate, syringic acid, catechin, catechol, methoxycatechol, benserazide, quercetin, tannic acid, phytic acid, ellagic acid, myricetin, fisetin, morin, kaempferol, rhamnetin, isorhamnetin, chrysin, luteolin, apigenin, baicalein, taxifolin, epicatechin, epigallocatechin, It may include at least one of epicatechin gallate, epigallocatechin gallate, and caffeic acid. Specifically, the pyrogallol compound may be pyrogallol.

[0046] The above-mentioned natural amine substance is an environmentally friendly substance derived from nature and may include an amine functional group capable of reacting with the pyrogallol compound. Specifically, the natural amine substance may include at least one of taurine, lysine, arginine, serotonin, mescaline, thiamine, pyridoxamine, cysteine, alliin, α-poly-lysine, ε-poly-lysine, poly-arginine, poly-histidine, poly-asparagine, poly-glutamine, poly-tryptophan, albumin, casein, chitosan, collagen, and gelatin. More specifically, the amine substance may be taurine.

[0047] The above base solvent can control the pH of the modified solution. The above base solvent can include at least one of tris-acetate-EDTA buffer (TAE buffer), tris-boric acid-EDTA buffer (TBE buffer), phosphate buffer saline (PBS buffer), Tris-HCl buffer, and sodium hydroxide (NaOH) aqueous solution.

[0048] The above-mentioned modified solution may further include an oxidizing agent capable of accelerating the reaction between the pyrogallol compound and the naturally occurring amine substance. The oxidizing agent may include at least one of sodium periodate (NaIO4), lead tetraacetate (Pb(OAc)4), and potassium perruthenate (KRuO4). Specifically, the oxidizing agent may be sodium periodate (NaIO4).

[0049] In the above maintenance step, the pyrogallol compound and the natural amine substance can form at least one of the following chemical formulas 1 and 2 through at least one of a Michael addition reaction and a Schiff-base reaction.

[0050] (Chemical formula 1) , (chemical formula 2)

[0051] The above chemical formula 1 or chemical formula 2 may be provided on the inside or surface of the water treatment separation membrane. Specifically, when the in situ modification method is used, during the process of manufacturing the water treatment separation membrane by the non-solvent-induced phase separation method, the compound of the chemical formula 1 or chemical formula 2 may be formed and provided on the inside or surface of the water treatment separation membrane at the same time. The chemical formula 1 or chemical formula 2 may be provided not only on the surface but also on the inside of the water treatment separation membrane, thereby effectively hydrophilizing the water treatment separation membrane while maintaining the pore size of the water treatment separation membrane with little change.

[0052] Below, the reaction mechanism of the pyrogallol compound and the naturally occurring amine substance in the maintenance step is described. The reaction mechanism is described using pyrogallol as the pyrogallol compound, taurine as the naturally occurring amine substance, and sodium periodate (NaIO4) as the oxidizing agent, but the modified material is not limited thereto.

[0053]

[0054] The above pyrogallol can form a hydrophilic complex with the above naturally occurring amine substance through a Michael addition reaction or a Schiff base reaction. Pyrogallol is amphiphilic, and the aromatic portion of the pyrogallol in the hydrophilic complex can attach to a hydrophobic water treatment membrane, and the sulfonic acid group of the amine substance can provide hydrophilicity to the water treatment membrane and strengthen the negative charge.

[0055] In the above maintenance step, the first time may be 0.05 hours to 24 hours. If the first time is less than 0.05 hours, the reaction between the pyrogallol compound and the natural amine material does not sufficiently occur, so the effect of the modifying material is insufficient, and since modifying is sufficiently completed within 24 hours, if the first time exceeds this, the process efficiency is reduced. Specifically, the first time may be 0.05 hours to 20 hours, or 0.1 hours to 20 hours, or 1 hour to 20 hours, or 1 hour to 15 hours, or 5 hours to 15 hours, or 10 hours to 15 hours.

[0056] In the above modified material, the pyrogallol compound may be 0.001 wt% to 25 wt%, and the amine material may be 0.001 wt% to 25 wt%.

[0057] If the pyrogallol compound is less than 0.001 wt%, it is difficult for the modifying material to be stably fixed to the hydrophobic water treatment membrane, and if it exceeds 25 wt%, the phase separation behavior may be changed or excessively introduced into the membrane, thereby reducing performance. Specifically, the pyrogallol compound may be 0.001 wt% to 20 wt%, or 0.001 wt% to 15 wt%, or 0.001 wt% to 10 wt%, or 0.001 wt% to 8 wt%, or 0.005 wt% to 8 wt%, or 0.005 wt% to 5 wt%, or 0.01 wt% to 5 wt%, or 0.01 wt% to 3 wt%.

[0058] If the amount of the naturally occurring amine substance is less than 0.001 wt%, the hydrophilic effect of the water treatment membrane is insufficient, and if it exceeds 25 wt%, it becomes a problem because it is difficult for the water treatment membrane to be uniformly hydrophilicized as a whole. Specifically, the amount of the naturally occurring amine substance may be 0.001 wt% to 20 wt%, or 0.001 wt% to 15 wt%, or 0.001 wt% to 10 wt%, or 0.001 wt% to 8 wt%, or 0.005 wt% to 8 wt%, or 0.005 wt% to 5 wt%, or 0.01 wt% to 5 wt%, or 0.01 wt% to 3 wt%.

[0059] Preferably, the molar ratio of the natural amine material to the pyrogallol compound may be 1:0.1 to 5, or 1:0.1 to 4, or 1:3.5, or 1:0.1 to 2, or 1:0.5 to 2, or 1:0.7 to 8. More preferably, the molar ratio of the natural amine material to the pyrogallol compound may be 1:1. By providing the pyrogallol compound and the natural amine material in the molar ratio described above, the hydrophilic complex produced by the reaction of the pyrogallol compound and the natural amine material can effectively modify the water treatment separation membrane, thereby preventing problems such as a decrease in the pore size of the water treatment separation membrane from occurring.

[0060] When the above-mentioned modified material further comprises the oxidizing agent, the oxidizing agent may be present in an amount of 0.001 wt% to 15 wt%. If the amount of the oxidizing agent is less than 0.001 wt%, the degree of reaction acceleration by the oxidizing agent is insufficient, and 15 wt% is sufficient. Therefore, if the amount exceeds this, production costs may increase and process efficiency may decrease. Specifically, the oxidizing agent may be present in an amount of 0.001 wt% to 12 wt%, or 0.001 wt% to 10 wt%, or 0.001 wt% to 8 wt%, or 0.001 wt% to 6 wt%, or 0.001 wt% to 4 wt%, or 0.005 wt% to 4 wt%, or 0.01 wt% to 4 wt%, or 0.01 wt% to 2 wt%, or 0.05 wt% to 1 wt%.

[0061] The above polymer solution contains at least one of a polymer resin, an organic solvent, and a pore-forming agent, and the pore structure of the manufactured separation membrane can be controlled by controlling the composition of the polymer solution.

[0062] The above polymer solution can be prepared by dissolving a polymer resin in an organic solvent.

[0063] The polymer solution can be degassed by adding the polymer resin to the organic solvent, dissolving it at a temperature of 25°C to 90°C for 8 to 20 hours, and then slowly cooling it to room temperature while maintaining it for 4 to 15 hours.

[0064] In the process of dissolving the polymer solution, if the temperature is lower than 25°C, the polymer resin will not be sufficiently dissolved, which can be problematic, and if it is higher than 90°C, problems such as evaporation of the organic solvent or occurrence of undesirable reactions will occur. Specifically, in the process of dissolving the polymer solution, the temperature may be 25°C to 80°C, or 25°C to 75°C, or 30°C to 75°C, or 40°C to 75°C, or 50°C to 75°C, or 55°C to 75°C. By maintaining the above-described temperature range in the process of dissolving the polymer solution, the polymer solution can be efficiently dissolved, and the pore structure of the water treatment membrane manufactured using the polymer solution can be uniformly formed throughout. In addition, by performing the degassing for the above-described time, air bubbles in the polymer solution can be efficiently removed.

[0065] The polymer resin may include at least one of polyethersulfone, polyacrylonitrile, polyvinylpyrrolidone, polyethylene, polypropylene, polysulfone, polyacetylene, polyisobutylene, polyvinylchloride, polytetrafluoroethylene, polyphenylene sulfide, polystyrene, polydimethylsiloxane, polyvinylfluoride, polybenzimidazole, polyetherimide, polyvinylidene fluoride, and polyetheretherketone.

[0066] The organic solvent may include at least one of dimethyl sulfoxide, dimethylformamide, 1-methyl-2-pyrrolidone, and dimethylacetamide.

[0067] In the polymer solution, the content of the polymer resin may be 2 wt% to 40 wt%. If the content of the polymer resin is less than 2 wt%, it is difficult to cast into a film having a predetermined thickness, and if it exceeds 40 wt%, the porosity inside the water treatment separation membrane decreases, which is problematic. Specifically, the content of the polymer resin may be 2 wt% to 30 wt%, or 2 wt% to 25 wt%, or 4 wt% to 30 wt%, or 4 wt% to 25 wt%, or 4 wt% to 20 wt%.

[0068] The polymer solution may further contain 0.1 wt% to 50 wt% of a pore-forming agent based on the total weight of the polymer solution. If the pore-forming agent is contained in an amount of less than 0.1 wt%, the effect of pore formation by the pore-forming agent is minimal, and if it is contained in an amount of more than 50 wt%, the structure of the manufactured water treatment membrane may be significantly damaged, thereby reducing the mechanical strength and performance. Specifically, the pore-forming agent may be contained in an amount of 1 wt% to 50 wt%, or 10 wt% to 50 wt%, or 10 wt% to 40 wt%, or 20 wt% to 40 wt%, or 30 wt% to 40 wt%.

[0069] The above pore forming agent may include at least one of polyvinyl pyrrolidone, polyethylene glycol, lithium chloride, calcium chloride, iron chloride, zinc chloride, sodium bicarbonate, polyethylene oxide, propionic acid, and acetic acid.

[0070] According to another aspect of the present invention, the present invention includes a water treatment separation membrane manufactured according to the manufacturing method described above. The water treatment separation membrane may have an average pore diameter of 1 nm to 100 μm, a porosity of 1% to 90%, and a thickness of 1 μm to 1000 μm.

[0071] The water treatment separation membrane is made of a polymer resin having a plurality of pores, and the polymer resin is any one of polyethersulfone, polyacrylonitrile, polyvinylpyrrolidone, polyethylene, polypropylene, polysulfone, polyacetylene, polyisobutylene, polyvinylchloride, polytetrafluoroethylene, polyphenylene sulfide, polystyrene, polydimethylsiloxane, polyvinylfluoride, polybenzimidazole, polyetherimide, polyvinylidene fluoride, and polyetheretherketone. It can contain one or more.

[0072] The water treatment separation membrane comprises at least one of the following chemical formulas 1 and 2, wherein chemical formula 1 or chemical formula 2 may be provided on the interior or surface of a polymer resin constituting the water treatment separation membrane. The chemical formula 1 or chemical formula 2 may be fixed to a hydrophobic water treatment separation membrane, thereby providing hydrophilic properties to the water treatment separation membrane.

[0073] (Chemical formula 1) , (chemical formula 2)

[0074] The water treatment separation membrane of the present invention is made of a conventional hydrophobic polymer resin, but has increased hydrophilicity and negative charge on the surface, thereby preventing the attachment of organic pollutants and the like, thereby enabling effective water treatment for a long period of time.

[0075]

[0076] Hereinafter, examples and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention and the scope of the present invention is not limited by the following examples.

[0077]

[0078] Examples 1 to 4

[0079]

[0080] 1. Materials

[0081]

[0082] Hydrophobic membrane before modification

[0083] The membrane to be modified in situ was a PES ultrafiltration membrane manufactured directly.

[0084] Modified solution

[0085] Pyrogallol, which has amphiphilic properties and interacts with hydrophobic membranes, and taurine, which has an amine functional group that can react with pyrogallol, were used as modifying agents. To accelerate the reaction between pyrogallol and taurine, the pH of the modifying solution was controlled to a slightly basic pH (pH=8.5) using a Tris buffer, and NaIO4 was added as an oxidizing agent.

[0086]

[0087] Hydrophilic modified membrane

[0088] To evaluate the effectiveness of in situ modified PES ultrafiltration membranes, in which membrane preparation and modification were simultaneously performed using a modified solution of a combination of pyrogallol and taurine, ex situ modified PES ultrafiltration membranes were manufactured using a modified solution of a combination of pyrogallol and taurine. In addition, to confirm the in situ modification effect of the combination of pyrogallol and taurine, in situ modified PES ultrafiltration membranes were manufactured using a modified solution containing only pyrogallol and in situ modified PES ultrafiltration membranes using a modified solution containing only taurine, respectively.

[0089]

[0090] 2. Membrane modification method

[0091]

[0092] A PES ultrafiltration membrane before modification was prepared using a non-solvent-induced phase separation method. 18 wt% PES and 4.5 wt% PVP were added to 77.5 wt% dimethylacetamide (DMAc) and sufficiently dissolved at 60°C for 12 hours. After complete dissolution, the solution was cooled to room temperature and degassed for 12 hours to remove air bubbles contained within, thereby preparing a polymer solution. The prepared polymer solution was cast onto a glass plate to a thickness of 160 μm. The cast film was sufficiently immersed in a non-solvent water bath together with the glass plate for 12 hours to induce phase separation, thereby preparing an unmodified PES ultrafiltration membrane. The prepared PES ultrafiltration membrane was stored in distilled water.

[0093] To prepare an ex situ modified PES ultrafiltration membrane (ex-situ_P+T), the unmodified PES ultrafiltration membrane prepared above was soaked in a modification solution (Tris-buffer (pH=8.5) containing pyrogallol (0.2 wt%), taurine (0.2 wt%), and oxidant (0.1 wt%)) for 12 hours, washed with distilled water, and stored.

[0094] To fabricate an in situ modified PES ultrafiltration membrane (in-situ_P+T), the polymer solution prepared by the above-described method was used. The polymer solution was cast on a glass plate with a thickness of 160 μm, and the cast polymer solution film was immersed in a modified solution (Tris-buffer (pH=8.5) containing pyrogallol (0.2 wt%), taurine (0.2 wt%), and an oxidizing agent (0.1 wt%)) for 12 h, thereby simultaneously fabricating and modifying the membrane. The fabricated membrane was washed with distilled water and stored.

[0095] In situ modified membranes (respectively in-situ_P and in-situ_T) were manufactured similarly to the method described above, but using a modified solution containing only pyrogallol and no taurine, or using a modified solution containing only taurine and no pyrogallol, respectively. Specifically, after casting under the same conditions using a polymer solution, the cast polymer solution film was immersed in a modified solution (pyrogallol alone or taurine alone and Tris-buffer containing an oxidizing agent) together with a glass plate for 12 hours, washed with distilled water, and stored.

[0096]

[0097] Comparative example

[0098]

[0099] A PES ultrafiltration membrane manufactured in the same manner as in the examples but not modified with a modification solution was used as a comparative example.

[0100]

[0101] Membrane evaluation methods and results

[0102]

[0103] Membrane evaluation method

[0104] Using cross-filtration equipment, distilled water was permeated for 12 hours under pressure conditions of 3 bar, and then stabilized. Then, the water permeability of the membrane and the fouling resistance against organic matter under flow conditions were measured. The water permeability is the amount of water permeated per unit area of ​​the membrane and per unit time (Lm -2 h -1 , LMH). The fouling resistance to organic matter under static conditions is 0.2 g L in a darkroom with PBS buffer solution controlled to pH 7. -1 After immersing the membrane in a fluorescent BSA solution for 3 hours, the membrane was washed with a PBS buffer solution, and images of the membrane surface and cross-section were observed using a confocal scanning microscope. The organic fouling resistance of the membrane under flow conditions was evaluated by measuring the change in permeability of the foulant (BSA) solution over time, with the initial water permeability of the membrane set to 550 LMH.

[0105]

[0106] Membrane evaluation results

[0107] In order to evaluate the membrane modified in situ using a modified solution of a combination of pyrogallol and taurine (in-situ_P+T), an unmodified PES ultrafiltration membrane, a PES ultrafiltration membrane modified ex situ using a modified solution of a combination of pyrogallol and taurine (ex-situ_P+T), a PES ultrafiltration membrane modified in situ using a modified solution containing only pyrogallol (in-situ_P), and a PES ultrafiltration membrane modified in situ using a modified solution containing only taurine (in-situ_T) were manufactured, and the surface charge, water contact angle, and water permeability of each were measured, which are shown in Table 1.

[0108] Separation membrane surface charge (mV) Water contact angle (°) Water permeability (Lm -2 h -1 )Example 1in-situ_P+T-37.555.8235Example 2ex-situ_P+T-22.170.1140Example 3in-situ_P-26.765.1165Example 4in-situ_T-19.674.1155Comparative examplePES membrane before modification-19.878.0150

[0109] Figure 2 is a photograph of the surface color of the PES ultrafiltration membrane according to Comparative Example and Examples 1 to 4, and an SEM image confirming the surface and cross-sectional structure.

[0110] Referring to FIG. 2, when the same pyrogallol and taurine combination of modified solutions was used in Examples 1 and 2, no significant difference was observed in the structure, but it was confirmed that the change in surface color in Example 1, which was modified in situ, was greater than that in Example 2, which was modified ex situ.

[0111] The surface pore size of Comparative Example 1, which did not undergo modification, was 22 nm, Example 1 (in-situ_P+T) was 21.5 nm, Example 2 (ex-situ_P+T) was 18 nm, Example 3 (in-situ_P) was 21.3 nm, and Example 4 (in-situ_T) was 21.8 nm. That is, the degree of change in pore size was smaller when in-situ modification was performed compared to ex-situ modification.

[0112] Example 1 (in-situ_P+T) showed that during the non-solvent-induced phase separation process, the amphiphilic pyrogallol-taurine complex was partially impregnated into the membrane during solidification from a solution state, so that the modifying material was effectively introduced to the surface and interior of the membrane, and the change in pore size was also small.

[0113] Referring to Table 1, Example 1 had the lowest negative surface charge and the best water contact angle and water permeability. This is believed to be because, in the case of Example 1, the hydrophilic and negatively charged pyrogallol-taurine complex was most effectively introduced to the surface and interior of the membrane through in situ modification. In addition, as previously discussed, it was confirmed that the membrane modified in situ, such as Example 1, showed the highest water permeability by effectively making the surface hydrophilic while maintaining almost no change in pore size.

[0114] Example 2, despite using the same modified solution of pyrogallol and taurine as Example 1, in the ex situ modification, the pyrogallol-taurine complex was additionally introduced to the already solidified membrane, so it was mostly provided in the form of a coating on the surface, resulting in a high rate of reduction in pore size, and while hydrophilicity did not increase significantly, it showed the effect of reducing water permeability.

[0115] In the case of Example 3 (in-situ_P), due to the amphiphilicity of pyrogallol, during the non-solvent-induced phase separation process, pyrogallol was partially impregnated into the membrane during the solidification process from the solution state into a membrane, which slightly strengthened the negative charge and improved the hydrophilicity, but the effect was minimal. In Example 4 (in-situ_T), it was confirmed that taurine was difficult to effectively modify the membrane because it was a hydrophilic substance, and thus, there was almost no change in the physical properties and performance of the membrane.

[0116] Figure 3 is a confocal scanning microscope image of a PES ultrafiltration membrane according to Comparative Example and Examples 1 to 4 after exposure to a fluorescent protein solution.

[0117] Referring to Fig. 3, the results of confirming the fouling resistance performance of the membrane against organic matter under static conditions showed fouling resistance effects in the order of Example 1 > Examples 2 and 3 > Example 4, and Comparative Example. In the case of Example 1, the membrane was effectively hydrophilized by the pyrogallol-taurine complex, and as a result, the adhesion of the fluorescent protein was the lowest, so it showed the darkest color in the confocal scanning microscope image.

[0118] Figure 4 shows the results of evaluating the fouling resistance of organic matter (BSA) under flow conditions of PES ultrafiltration membranes according to comparative examples and examples 1 to 4.

[0119] Referring to Fig. 4, the results of confirming the fouling resistance performance of the membrane against organic substances under flow conditions were in the order of Example 1 > Example 3 > Example 2 > Example 4, and Comparative Example. In the case of Example 1, it was confirmed that the membrane was effectively hydrophilically modified, resulting in the smallest decrease in relative permeability. In other words, it was confirmed that when the combination of pyrogallol and taurine and the in situ method were used together, the membrane was most effectively hydrophilized, and thus, the fouling resistance against organic pollutants was excellent.

[0120] The method for manufacturing a water treatment separation membrane according to an embodiment of the present invention and the resulting water treatment separation membrane can effectively modify a polymer separation membrane having hydrophobic properties by using pyrogallol and taurine, which are environmentally friendly materials of natural origin. Furthermore, by using the modification solution combining pyrogallol and taurine according to the present embodiment, the membrane can be manufactured in situ while simultaneously being modified, thereby enhancing the modification effect and simplifying the manufacturing method.

[0121] Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering its technical spirit or essential characteristics. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims

1. Solution preparation step for preparing a modified solution; and A maintenance step for manufacturing a water treatment separation membrane by casting a polymer solution containing a polymer resin and maintaining the prepared film shape in the modified solution for a first time; The above modified solution is a method for manufacturing a water treatment separation membrane comprising a base solvent, a pyrogallol compound containing a pyrogallol functional group, and a naturally derived amine substance.

2. In paragraph 1, The above modified solution has a pH of 7.1 or higher, A method for manufacturing a water treatment separation membrane, wherein the first time is from 0.05 hours to 24 hours.

3. In paragraph 1, In the above solution preparation step, The above modified solution further contains an oxidizing agent, The above pyrogallol compound is 0.001 wt% to 25 wt%, The above naturally occurring amine substance is 0.001 wt% to 25 wt%, A method for manufacturing a water treatment separation membrane, wherein the oxidizing agent is 0.001 wt% to 15 wt%.

4. In paragraph 3, The above-mentioned natural amine substance includes at least one of taurine, lysine, arginine, serotonin, mescaline, thiamine, pyridoxamine, cysteine, alliin, α-poly-lysine, ε-poly-lysine, poly-arginine, poly-histidine, poly-asparagine, poly-glutamine, poly-tryptophan, albumin, casein, chitosan, collagen, and gelatin. The above pyrogallol compounds are pyrogallol, gallic acid, propyl gallate, syringic acid, catechin, catechol, methoxycatechol, benserazide, quercetin, tannic acid, phytic acid, ellagic acid, myricetin, fisetin, morin, kaempferol, rhamnetin, isorhamnetin, chrysin, luteolin, apigenin, baicalein, taxifolin, epicatechin, epigallocatechin, epicatechin At least one of epicatechin gallate, epigallocatechin gallate, and caffeic acid, The above base solvent includes at least one of tris-acetate-EDTA buffer (TAE buffer), tris-boric acid-EDTA buffer (TBE buffer), phosphate buffer saline (PBS buffer), Tris-HCl buffer, and sodium hydroxide (NaOH) aqueous solution. A method for manufacturing a water treatment separation membrane, wherein the oxidizing agent comprises at least one of sodium periodate (NaIO4), lead tetraacetate (Pb(OAc)4), and potassium perruthenate (KRuO4).

5. In paragraph 1, The above maintenance step is, Further comprising dissolving the polymer resin in an organic solvent to prepare a polymer solution, A method for manufacturing a water treatment separation membrane, wherein after casting the above polymer solution, the cast film form is maintained in a reaction vessel containing a modification solution, and manufacturing and modifying into a film form are performed simultaneously by a non-solvent induced phase separation (NIPS) method.

6. In paragraph 5, The above polymer solution is prepared by dissolving a polymer resin in an organic solvent, The polymer resin includes at least one of polyethersulfone, polyacrylonitrile, polyvinylpyrrolidone, polyethylene, polypropylene, polysulfone, polyacetylene, polyisobutylene, polyvinylchloride, polytetrafluoroethylene, polyphenylene sulfide, polystyrene, polydimethylsiloxane, polyvinylfluoride, polybenzimidazole, polyetherimide, polyvinylidene fluoride, and polyetheretherketone. A method for manufacturing a water treatment separation membrane, wherein the organic solvent comprises at least one of dimethyl sulfoxide, dimethylformamide, 1-methyl-2-pyrrolidone, and dimethylacetamide.

7. In paragraph 6, A method for manufacturing a water treatment separation membrane, wherein the content of the polymer resin in the above polymer solution is 2 wt% to 40 wt%.

8. In paragraph 6, The above polymer solution further contains 0.1 wt% to 50 wt% of a pore-forming agent based on the total weight of the polymer solution, A method for manufacturing a water treatment separation membrane, wherein the pore forming agent comprises at least one of polyvinyl pyrrolidone, polyethylene glycol, lithium chloride, calcium chloride, iron chloride, zinc chloride, sodium bicarbonate, polyethylene oxide, propionic acid, and acetic acid.

9. In paragraph 1, In the above maintenance step, A method for manufacturing a water treatment separation membrane in which the above pyrogallol compound and the above naturally occurring amine substance form at least one of the following chemical formulas 1 and 2 through at least one of a Michael addition reaction and a Schiff-base reaction: (Chemical formula 1) , (chemical formula 2) .

10. In paragraph 9, A method for manufacturing a water treatment separation membrane, wherein at least one of the chemical formulas 1 and 2 is provided on the inside or surface of the water treatment separation membrane.

11. A water treatment separation membrane manufactured according to any one of clauses 1 to 10, The above water treatment separation membrane is a water treatment separation membrane having an average pore diameter of 1 nm to 100 μm, a porosity of 1% to 90%, and a thickness of 1 μm to 1000 μm.

12. In paragraph 11, The water treatment separation membrane is made of polymer resin, The polymer resin includes at least one of polyethersulfone, polyacrylonitrile, polyvinylpyrrolidone, polyethylene, polypropylene, polysulfone, polyacetylene, polyisobutylene, polyvinylchloride, polytetrafluoroethylene, polyphenylene sulfide, polystyrene, polydimethylsiloxane, polyvinylfluoride, polybenzimidazole, polyetherimide, polyvinylidene fluoride, and polyetheretherketone. The above water treatment separation membrane is a water treatment separation membrane comprising at least one of the following chemical formulas 1 and 2: (Chemical formula 1) , (chemical formula 2) .

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