Hydrophilic modified polymer membrane and manufacturing method thereof

Abstract

The present invention relates to a hydrophilically modified polymer separation membrane and a method for manufacturing the same. More specifically, the invention relates to a hydrophilically modified polymer separation membrane and a method for manufacturing the same, wherein double bond-contained PVDF (DPVDF) containing double bonds is dip-coated onto a porous polymer substrate and a polymer or monomer containing amine groups is reacted. The polymer separation membrane of the present invention is physically coated by dip-coating with DPVDF, and then the surface of the separation membrane is chemically modified to be hydrophilic using a polymer or monomer containing an amine group. That is, the polymer separation membrane of the present invention can further suppress the leaching of inorganic particles within the separation membrane by performing physical coating and chemical modification together.

Description

Technology Field

[0001] The present invention relates to a hydrophilically modified polymer separation membrane and a method for manufacturing the same. More specifically, the invention relates to a hydrophilically modified polymer separation membrane and a method for manufacturing the same, wherein double bond-contained PVDF (DPVDF) containing double bonds is dip-coated onto a porous polymer substrate and a polymer or monomer containing amine groups is reacted. Background Technology

[0003] Polymer membranes are utilized in various fields, including water treatment, protein purification processes for pharmaceutical development, virus filters, seawater desalination, industrial wastewater treatment facilities, and bacterial separation processes in the food industry. Currently, most polymer membranes used in separation processes are imported from abroad, leading to a situation where many industries are dependent on foreign companies.

[0004] Materials used for polymer separation membranes include polyvinylidene fluoride (PVDF); polysulfone (PSF); and polypropylene (PP). Since most of the materials primarily used for the above polymer separation membranes have hydrophobic properties, there is a problem in that hydrophobic contaminants such as bacteria, viruses, proteins, and emulsions are adsorbed onto the membrane surface, blocking pores and shortening the lifespan of the separation membrane. Therefore, it is desirable for the separation membrane to have hydrophilic properties; however, if a polymer separation membrane is manufactured using a hydrophilic material, problems may arise such as blocking pores during coating or hydrophilic polymers dissolving in water and leaching out.

[0005] To resolve these issues, it is desirable to modify separation membranes made of hydrophobic materials to be hydrophilic to minimize the adsorption of the aforementioned contaminants. Conventional methods for modifying separation membranes to be hydrophilic include using hydrophilic polymers or inorganic particles as additives; however, the method of adding hydrophilic polymers has limitations, such as changes in the pore structure and the potential for polymer materials to escape from the membrane. Additionally, the method of using inorganic particles as additives also has limitations, such as instability under acidic conditions and incomplete coating.

[0006] In order to overcome the problems and limitations of the conventional technology described above, there is a growing need for research on new methods to modify polymer separation membranes to be hydrophilic. Prior art literature

[0008] Republic of Korea Registered Patent Publication No. 10-1715229 The problem to be solved

[0009] The objective of the present invention is to provide a polymer separation membrane modified to be hydrophilic by dip-coating a hydrophobic porous polymer substrate with double bond-contained PVDF (DPVDF) and then reacting it with a polymer or monomer containing an amine group.

[0010] Another objective of the present invention is to provide a method for manufacturing a polymer separation membrane by dip-coating a hydrophobic porous polymer substrate with double bond-contained PVDF (DPVDF) and then reacting it with a polymer or monomer containing an amine group to modify it to be hydrophilic.

[0011] The technical problems that the invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems can be clearly understood by those skilled in the art from the description of the invention. means of solving the problem

[0013] The present invention provides a polymer separation membrane comprising a porous polymer substrate and a coating layer formed on at least one surface of the porous polymer substrate, wherein the coating layer induces a Michael addition reaction between a double bond-containing PVDF (Double bond-contained PVDF, DPVDF); a polymer containing at least one amine group or a monomer containing at least one amine group; and wherein, as the double bond of the DPVDF becomes saturated, a bond is formed between the DPVDF; and the polymer containing at least one amine group or the monomer containing at least one amine group.

[0014] In the present invention, the polymer separation membrane is characterized by being used for water treatment, virus filters, pretreatment devices for seawater desalination processes, or food purification devices.

[0015] In addition, the present invention provides a method for manufacturing a polymer separation membrane characterized by comprising: a step of dip-coating a porous polymer substrate with double bond-contained PVDF (DPVDF); and a step of hydrophilizing the dip-coated substrate by immersing it in a solution containing at least one amine group or a monomer containing at least one amine group.

[0016] In the present invention, the method for manufacturing the polymer separation membrane is characterized by further including drying and rinsing steps.

[0017] In the present invention, the porous polymer substrate is characterized by comprising one or more selected from the group consisting of polyvinylidene fluoride (PVDF); polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP); polysulfone (PSF); polypropylene (PP); polyethylene (PE); and cellulose acetate.

[0018] In the present invention, the polymer comprising at least one amine group is characterized as being one or more polymers selected from the group consisting of Jeffamine D-230; linear polyethyleneimine; branched polyethyleneimine (BPEI); polyacrylamide; and polyethylene glycol diamine.

[0019] In the present invention, the monomer comprising at least one amine group is characterized as being one or more monomers selected from the group consisting of Jeffamine EDR 148; Ethylene diamine (EDA); Triethylenetetramine (TETA); Hexamethylenediamine (HMDA); Diaminopropane (1,3-diaminopropane); and Diethylene triamine (DETA).

[0020] In the present invention, the step of dip-coating the porous polymer substrate with double bond-contained PVDF (DPVDF) is characterized by immersing the porous polymer substrate in a solution containing the DPVDF to dip-coate, wherein the solution containing the DPVDF is a solution in which the DPVDF is mixed at a concentration of 0.03 to 0.3 wt% in a solvent in which acetone and ethanol are mixed in a weight ratio of 0.8 to 3:1.

[0021] In the present invention, the solution comprising a polymer containing at least one amine group or a monomer containing at least one amine group is characterized as being a solution containing branched polyethyleneimine (BPEI) at a concentration of 0.6 to 0.9 M. Effects of the invention

[0023] The present invention can provide a polymer separation membrane modified to be hydrophilic by dip-coating a hydrophobic porous polymer substrate with double bond-contained PVDF (DPVDF) and then reacting it with a polymer or monomer containing an amine group.

[0024] In addition, the present invention can provide a method for manufacturing a polymer separation membrane by dip-coating a hydrophobic porous polymer substrate with double bond-contained PVDF (DPVDF) and then reacting it with a polymer or monomer containing an amine group to modify it to be hydrophilic.

[0025] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0027] Figure 1 is a schematic diagram showing a method for manufacturing a polymer separation membrane modified to be hydrophilic by introducing BPEI after DPVDF dip coating. Figure 2 is a figure showing polymers and monomers that can be used for hydrophilic modification of the polymer separation membrane of the present invention. Figure 3 is a schematic diagram showing a method for manufacturing a polymer separation membrane modified to be hydrophilic by introducing BPEI after DPVDF dip coating. Figure 4 shows the results of evaluating the stability of the separation membrane according to the mixing ratio of acetone and ethanol in the DPVDF dip-coating solution. Figure 5 shows the results of comparing the pore size and number of membranes according to the concentration of DPVDF during dip coating. Figure 6 shows the results of comparing the pore size of the membrane according to the concentration of DPVDF during dip coating. Figure 7 shows the results of comparing the FT-IR peaks, water contact angle, and water permeability of the membrane according to the concentration of DPVDF during dip coating. Figure 8 shows the results of comparing the FT-IR peaks and water contact angles of the membrane according to the BPEI concentration during hydrophilic modification. Figure 9 shows the results of comparing the pore structure of the membrane according to the BPEI concentration during hydrophilic modification. Figure 10 shows the results of comparing the water permeability of the membrane according to the BPEI concentration during hydrophilic modification. Figure 11 shows the results of analyzing the types of elements in the membrane after hydrophilic modification. Figure 12 shows the results of analyzing the BSA solution permeation rate and protein adsorption capacity of the hydrophilically modified membrane of the present invention. Figure 13 shows the results of analyzing FT-IR peaks and water contact angles according to Zepamin D-230 concentration during hydrophilic modification. Figure 14 shows the results of analyzing FT-IR peaks and water contact angles according to the type of monomer used during hydrophilic modification. Figure 15 shows the results of the virus removal effect of the hydrophilically modified separation membrane of the present invention. Specific details for implementing the invention

[0028] The terms used in this specification have been selected based on currently widely used general terms whenever possible, taking into account their functions in the present invention; however, these terms may vary depending on the intent of those skilled in the art, case law, the emergence of new technologies, etc. Additionally, in specific cases, terms have been arbitrarily selected by the applicant, and in such cases, their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this invention should be defined not merely by their names, but based on their meanings and the overall content of the invention.

[0029] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0030] Numerical ranges include the values ​​defined in the above ranges. All maximum numerical limits given throughout this specification include all lower numerical limits as clearly written. All minimum numerical limits given throughout this specification include all higher numerical limits as clearly written. All numerical limits given throughout this specification will include all better numerical ranges within a wider numerical range, as clearly written.

[0032] The present invention will be described in detail below.

[0034] polymer separation membrane

[0035] The present invention provides a polymer separation membrane characterized by comprising a porous polymer substrate and a coating layer formed on at least one surface of the porous polymer substrate, wherein the coating layer comprises PVDF (Double bond-contained PVDF, DPVDF) containing double bonds; and a polymer containing at least one amine group or a monomer containing at least one amine group.

[0036] In the present invention, the porous polymer substrate may include one or more selected from the group consisting of polyvinylidene fluoride (PVDF); polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP); polysulfone (PSF); polypropylene (PP); polyethylene (PE); and cellulose acetate; preferably, it may include polyvinylidene fluoride (PVDF) or polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), and more preferably, it may include polyvinylidene fluoride-hexafluoropropene (PVDF-HFP).

[0037] In the present invention, the polymer comprising at least one amine group may be one or more polymers selected from the group consisting of Jeffamine D-230; linear polyethyleneimine; branched polyethyleneimine (BPEI); polyacrylamide; and polyethylene glycol diamine; preferably, it may be one or more polymers selected from the group consisting of Jeffamine D-230; and branched polyethyleneimine (BPEI); and more preferably, it may be Jeffamine D-230; or branched polyethyleneimine (BPEI).

[0038] In the present invention, the monomer comprising at least one amine group may be one or more monomers selected from the group consisting of Jeffamine EDR 148; ethylene diamine (EDA); triethylenetetramine (TETA); hexamethylenediamine (HMDA); diaminopropane (1,3-diaminopropane); and diethylene triamine (DETA); preferably, it may be one or more monomers selected from the group consisting of ethylene diamine (EDA); triethylenetetramine (TETA); and diethylene triamine (DETA); and more preferably, it may be ethylene diamine (EDA); triethylenetetramine (TETA); or diethylene triamine (DETA).

[0039] According to one embodiment of the present invention, the polymer separation membrane can be used for water treatment, virus filters, pretreatment devices for seawater desalination processes, or food purification devices.

[0041] Method for manufacturing a polymer separation membrane

[0042] The present invention provides a method for manufacturing a polymer separation membrane, characterized by comprising: a step of dip-coating a porous polymer substrate with double bond-contained PVDF (DPVDF); and a step of hydrophilizing the dip-coated substrate by immersing it in a solution containing at least one amine group or a monomer containing at least one amine group.

[0043] The method for manufacturing the polymer separation membrane described above may further include drying and rinsing steps. The drying and rinsing steps may be characterized by drying at a temperature of 70 to 90°C for 5 to 15 minutes and then rinsing.

[0044] In the present invention, the porous polymer substrate may include one or more selected from the group consisting of polyvinylidene fluoride (PVDF); polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP); polysulfone (PSF); polypropylene (PP); polyethylene (PE); and cellulose acetate; preferably, it may include polyvinylidene fluoride (PVDF) or polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), and more preferably, it may include polyvinylidene fluoride-hexafluoropropene (PVDF-HFP).

[0045] In the method for manufacturing the above polymer separation membrane, the step of dip-coating a porous polymer substrate with double bond-contained PVDF (DPVDF) may be a step of immersing the porous polymer substrate in a solution containing the DPVDF to dip-coate it. The solution containing the DPVDF may be a solution in which DPVDF is mixed at a concentration of 0.03 to 0.3 wt% in a solvent in which acetone and ethanol are mixed in a weight ratio of 0.8 to 3:1, preferably a solution in which DPVDF is mixed at a concentration of 0.03 to 0.15 wt% in a solvent in which acetone and ethanol are mixed in a weight ratio of 0.8 to 3:1, and more preferably a solution in which DPVDF is mixed at a concentration of 0.03 to 0.07 wt% in a solvent in which acetone and ethanol are mixed in a weight ratio of 0.8 to 3:1.

[0046] In the step of dip-coating the porous polymer substrate with double bond-contained PVDF (DPVDF), the temperature and time for immersing the porous polymer substrate in a solution containing the DPVDF may be 15 to 25°C and 5 to 20 seconds.

[0047] The step of hydrophilizing the above dip-coated substrate by immersing it in a solution containing a polymer containing at least one amine group or a monomer containing at least one amine group may be a step of hydrophilizing the above dip-coated substrate by immersing it in a solution containing a polymer containing at least one amine group or a monomer containing at least one amine group to induce a Michael-addition reaction between the DPVDF and the polymer or monomer.

[0048] In the present invention, the polymer comprising at least one amine group may be one or more polymers selected from the group consisting of Jeffamine D-230; linear polyethyleneimine; branched polyethyleneimine (BPEI); polyacrylamide; and polyethylene glycol diamine; preferably, it may be one or more polymers selected from the group consisting of Jeffamine D-230; and branched polyethyleneimine (BPEI); and more preferably, it may be Jeffamine D-230; or branched polyethyleneimine (BPEI).

[0049] In the present invention, the monomer comprising at least one amine group may be one or more monomers selected from the group consisting of Jeffamine EDR 148; ethylene diamine (EDA); triethylenetetramine (TETA); hexamethylenediamine (HMDA); diaminopropane (1,3-diaminopropane); and diethylene triamine (DETA); preferably, it may be one or more monomers selected from the group consisting of ethylene diamine (EDA); triethylenetetramine (TETA); and diethylene triamine (DETA); and more preferably, it may be ethylene diamine (EDA); triethylenetetramine (TETA); or diethylene triamine (DETA).

[0050] Preferably, the solution containing a polymer containing at least one amine group or a monomer containing at least one amine group may be a solution in which 0.4 to 1.2 M of the branched polyethyleneimine (BPEI) is mixed in an ethanol solvent, and more preferably, the solution may be a solution in which 0.6 to 0.9 M of the branched polyethyleneimine (BPEI) is mixed in an ethanol solvent.

[0051] In addition, the present invention can provide a polymer separation membrane manufactured according to the method for manufacturing a polymer separation membrane described above.

[0052] The method for manufacturing a polymer separation membrane according to the present invention may relate to a method of physically coating a porous polymer substrate by dip-coating with DPVDF, and then chemically modifying the separation membrane to be hydrophilic using a polymer or monomer containing an amine group. That is, it relates to a method in which physical coating and chemical coating are performed together to further suppress the possibility of material leaching from the separation membrane.

[0053] If the membrane is chemically modified to be hydrophilic using a polymer or monomer containing an amine group without a dip-coating process with DPVDF, inorganic particles may escape from the membrane and contaminate the purified solution during membrane operation. However, according to the manufacturing method of the present invention, which involves dip-coating with DPVDF and then chemically modifying the membrane to be hydrophilic using a polymer or monomer containing an amine group, the bonding between the DPVDF and the polymer or monomer containing an amine group is excellent, so the possibility of inorganic particles escaping from the membrane and contaminating the purified solution can be reduced.

[0055] The embodiments of the present invention are described in detail below, but it is obvious that the present invention is not limited by the following embodiments.

[0057] Example 1. Preparation of a polymer separation membrane hydrophilically modified by branched polyethyleneimine (BPEI)

[0059] 1-1. DPVDF Dip Coating

[0060] A PVDF-HFP membrane was prepared based on the non-solvent induced phase separation (NIPS) method. Next, a dip-coating solution was prepared by mixing 0.05 wt% of double bond-contained PVDF (DPVDF) into a solvent of acetone and ethanol mixed in a 5:5 ratio. Dip-coating was performed by immersing the PVDF-HFP membrane in the dip-coating solution at room temperature for 10 seconds.

[0062] 1-2. Hydrophilic Modification

[0063] The separator membrane dip-coated in Example 1-1 above was modified to be hydrophilic by reacting it with branched polyethyleneimine (BPEI). First, a BPEI solution was prepared. The solution was prepared by dissolving BPEI at a concentration of 0.75 M in an ethanol solvent. The separator membrane dip-coated in Example 1-1 above was immersed in the BPEI solution for 20 seconds, and then dried at 80°C for 10 minutes. During the immersion and drying process, a Michael addition reaction between the DPVDF coated on the separator membrane and BPEI is induced. The method for manufacturing the separator membrane disclosed in Example 1 above is schematically illustrated in FIGS. 1 and FIGS. 3.

[0065] Experimental Example 1. Analysis of membrane stability according to DPVDF dip-coating solution ratio

[0066] In Example 1 above, a solvent prepared by mixing acetone and ethanol in a 5:5 ratio was used as the solvent for the solution during DPVDF dip coating. In Experimental Example 1 above, the stability of the membrane during dip coating was analyzed according to the ratio of acetone and ethanol. Solvents prepared by mixing acetone and ethanol in ratios of 9:1, 8:2, 7:3, 6:4, or 5:5 were prepared, respectively, and PVDF-HFP membranes were coated by immersing them in each of the solvents with different mixing ratios at room temperature for 10 seconds. The results of Experimental Example 1 above are illustrated in Figure 4.

[0067] As a result of Experimental Example 1, it was confirmed that the separation membrane dissolved and disappeared in solvents mixed with acetone and ethanol in a ratio of 9:1 or 8:2, but remained stable without dissolving in solvents mixed in a ratio of 7:3 or 5:5. In particular, the separation membrane was most stable in the solvent mixed with acetone and ethanol in a ratio of 5:5.

[0068] Accordingly, the PVDF-HFP membrane was immersed for 30 minutes in a solvent consisting of a 5:5 mixture of acetone and ethanol that did not contain DPVDF, and the pore structure was observed using an SEM microscope. The pore structure was observed at a magnification of 50,000X using a TESCAN MIRA3 model. Subsequently, the pore size was analyzed using a Porometer Porolux 1000; more specifically, the pore size was analyzed using the Gas-Liquid Porometry method, which analyzes the permeable flow rate while increasing the pressure from 0 to 300 psi. The observed results are shown in Figure 4, confirming that the pore structure and size remained unchanged.

[0070] Experimental Example 2. Analysis of Pore Structure of Separator According to DPVDF Concentration During Dip Coating

[0071] Experimental Example 2 was conducted to analyze the pore size and number of membranes according to the DPVDF concentration during dip coating. In Experimental Example 2, a membrane dip-coated with DPVDF was prepared in the same manner as in Example 1-1. However, the concentration of DPVDF was prepared differently at 0.05, 0.1, or 0.25 wt%, respectively, and all other preparation methods were carried out in the same manner as in Example 1-1.

[0072] The pore size and number of the membranes prepared above at different DPVDF concentrations were observed using an SEM microscope, and the observed microscopic results are shown in Figure 5. In Figure 5, the membrane not coated with DPVDF was named KP, and the membranes using DPVDF concentrations of 0.05, 0.1, and 0.25 wt% were named KPD5, KPD10, and KPD25, respectively. As a result, as the DPVDF concentration increased, the pore size and number of the membranes decreased.

[0073] In addition, the pore sizes of the above KP, KPD5, KPD10, and KPD25 were analyzed using a Porometer Porolux 1000 instrument, and the results of the analysis are shown as a graph in Figure 6. The pore size of the above KP was confirmed to be 54.51 nm, the pore size of the above KPD5 was 48.02 nm, the pore size of the above KPD10 was 44.32 nm, and the pore size of the above KPD25 was 31.81 nm.

[0075] Experimental Example 3. Analysis of Surface Characteristics and Water Permeability of Dip-Coated Separator with DPVDF

[0076] Separator membranes were prepared using DPVDF concentrations of 0.05, 0.1, and 0.25 wt%, respectively, in the same manner as in Experimental Example 2, and were named KPD5, KPD10, and KPD25, respectively, in the same manner as in Experimental Example 2. Likewise, a separator membrane not coated with DPVDF was prepared and named KP.

[0077] The double bond peaks between carbon atoms contained in DPVDF were confirmed using FT-IR for the above KP, KP5, KP10, and KP25. The FT-IR was performed using the Thermofisher iS10 model, and the FT-IR measurement method was performed using a dried film based on the ATR mode.

[0078] In addition, the water contact angles of the above KP, KP5, KP10, and KP25 were analyzed. The water contact angles were measured using the SEO Phoenix 300 model and were determined based on the interface angle between the membrane and the water droplet using 5 μl of water droplet according to the ASTM D5946 method using deionized water.

[0079] In addition, the water permeability of the above KP, KP5, KP10, and KP25 was also analyzed. The water permeability analysis was conducted using a filtration drive method utilizing a deadend cell. More specifically, when pressure is applied with nitrogen gas to a container holding the feed solution, the liquid inside the container flows through a tube into the deadend cell. At this time, the incoming liquid is filtered through a membrane located at the bottom of the deadend cell, and the weight of the filtered solution was recorded using an electronic balance. Based on the recorded weight, a result value called LMH was obtained, which represents the volume of the solution permeated per unit area.

[0080] The results of confirming the double bond peak between the carbon atoms are shown in Fig. 7A, the results of analyzing the water contact angle are shown in Fig. 7B, and the results of analyzing the water permeability are shown in Fig. 7C.

[0081] As a result of Experimental Example 3, as the DPVDF concentration during dip coating increased, the double bond peak between carbon atoms contained in DPVDF (~1720 cm⁻¹) -1 It was confirmed that the water contact angle increased (Fig. 7A). In addition, as the DPVDF concentration increased, the roughness of the membrane surface increased and the water contact angle also increased (Fig. 7B). Finally, as the DPVDF concentration increased, the water permeability decreased; the water permeability dropped sharply at a DPVDF concentration of 0.25 wt%, and the decrease in water permeability was smallest at a concentration of 0.05 wt%. Therefore, it is determined that a DPVDF concentration of 0.05 wt% is most suitable for dip coating polymer membranes.

[0083] Experimental Example 4. FT-IR and Water Contact Angle Analysis According to Branched Polyethyleneimine (BPEI) Concentration

[0084] Experimental Example 4 was conducted to analyze FT-IR peaks and water contact angles according to the concentration of branched polyethyleneimine (BPEI) introduced into a DPVDF dip-coated membrane. First, a PVDF-HFP membrane was coated with DPVDF in the same manner as in Example 1, and then modified to be hydrophilic by reacting with BPEI. However, in Experimental Example 4, the BPEI was dissolved in an ethanol solvent at concentrations of 0.5, 0.75, or 1 M for modification, respectively. In Experimental Example 4, the membrane prepared using 0.5 M of BPEI was named KPD-P5C, the membrane prepared using 0.75 M was named KPD-P7.5C, and the membrane prepared using 1 M was named KPD-P10C. In addition, a film that underwent only DPVDF dip coating without introducing BPEI was named KPD, and a film that underwent neither BPEI introduction nor DPVDF dip coating was named KP. The results of analyzing the FT-IR peaks of the above KP, KPD, KPD P5C, KPD P7.5C, and KPD P10C are shown in Fig. 8A, and the results of analyzing the water contact angle are shown in Fig. 8B.

[0085] The FT-IR and water contact angle analysis of Experimental Example 4 above were performed in the same manner as in Experimental Example 3 above. However, in Experimental Example 4 above, a washing process using ethanol at 30°C for 6 hours was additionally performed.

[0086] As a result of Experimental Example 4, as the BPEI concentration increased, the NH bending peaks at ~1650 and ~1580 cm⁻¹ -1 The peak increased (Fig. 8A). In addition, the water contact angle decreased as the BPEI concentration increased (Fig. 8B).

[0088] Experimental Example 5. Analysis of Optimal Branched Polyethyleneimine (BPEI) Concentration in Polymer Membrane Manufacturing

[0090] 5-1. Analysis of Pore Structure of Separator Membranes According to Branched Polyethyleneimine (BPEI) Concentration

[0091] Experimental Example 5-1 was conducted to analyze the pore structure of a membrane according to the concentration of branched polyethyleneimine (BPEI) introduced into a DPVDF dip-coated membrane. In the same manner as in Experimental Example 4, membranes KP, KPD P5C, KPD P7.5C, and KPD P10C were prepared by introducing BPEI at different concentrations.

[0092] The pore structures of the above KP, KPD P5C, KPD P7.5C, and KPD P10C were observed using an SEM microscope, and the observation method was carried out in the same manner as in Experimental Example 1. The results of the observation are shown in Fig. 9.

[0093] As a result of Experimental Example 5-1, it was confirmed that when the BPEI is introduced at a level of 0.5 or 0.75 M, the pore structure is maintained, but when the BPEI is introduced at a level of 1 M, the number and size of the pores decrease.

[0095] 5-2. Analysis of Water Permeability of Separator Membranes According to Branched Polyethyleneimine (BPEI) Concentration

[0096] Experimental Example 5-1 was conducted to analyze the water permeability of a membrane according to the concentration of branched polyethyleneimine (BPEI) introduced into a DPVDF dip-coated membrane. In the same manner as in Experimental Example 4, membranes KP, KPD P5C, KPD P7.5C, and KPD P10C were prepared by introducing BPEI at different concentrations.

[0097] The water permeability analysis of the above KP, KPD P5C, KPD P7.5C, and KPD P10C was carried out in the same manner as in Experimental Example 3, and the results of the water permeability analysis are shown in Fig. 10.

[0098] As a result of Experimental Example 5-2, the water permeability increased in the membrane (KPD P5C) with 0.5 M of BPEI introduced compared to the membrane (M) without BPEI introduced, and the water permeability was highest in the membrane (KPD P7.5C) with 0.75 M introduced. However, the water permeability was lower in the membrane (KPD P10C) with 1 M of BPEI introduced compared to the KPD P5C (Fig. 10). Therefore, it is determined that introducing 0.75 M of BPEI is most desirable for manufacturing the polymer separation membrane of the present invention.

[0100] Experimental Example 6. Elemental analysis of a hydrophilically modified membrane

[0101] A polymer separation membrane was prepared in the same manner as in Example 1 above. More specifically, in the same manner as in Example 1 above, a PVDF-HFP membrane was dip-coated with a dip-coating solution containing 0.05 wt% DPVDF in a solvent mixed with acetone and ethanol in a 5:5 ratio, and then the membrane was hydrophilically modified using a solution in which BPEI was dissolved to a concentration of 0.75 M in an ethanol solvent, and the membrane was elementally analyzed. In Experimental Example 6 above, the elements were analyzed using the EDS (Energy dispersive spectrometer) mapping method, and the results of Experimental Example 6 are shown in Fig. 11.

[0102] As a result of Experimental Example 6, it was confirmed that nitrogen (N) elements appeared evenly throughout the membrane after hydrophilic modification compared to the membrane before hydrophilic modification. In addition, the pore structure of the membrane cross-section remained unchanged even after hydrophilic modification (Fig. 11).

[0104] Experimental Example 7. Confirmation of BSA solution permeation rate and removal rate of hydrophilically modified membrane

[0105] Experimental Example 7 was conducted to verify the BSA solution permeation rate and removal rate of a polymer membrane prepared in the same manner as in Example 1. The method used to analyze the BSA solution permeation rate in Experimental Example 7 was the same as in Experimental Example 3. However, while deionized water was used as the permeation solution in Experimental Example 3, a solution prepared by dissolving BSA in PBS at a concentration of 1 g / L was used as the permeation solution in Experimental Example 7. All other experimental methods were carried out in the same manner as in Experimental Example 3. The experimental results of Experimental Example 7 are shown in Fig. 12.

[0106] As a result of Experimental Example 7, the permeation rate of the BSA solution of the DPVDF dip-coated and hydrophilically modified membrane increased (Fig. 12A), and it was confirmed that the protein adsorption performance was low (Fig. 12B).

[0108] Example 2. Preparation of a polymer separation membrane hydrophilically modified by Jeffamine D-230

[0109] Example 2 was carried out to prepare a polymer separation membrane modified to be hydrophilic by dip-coating with DPVDF and reacting with Jeffamine D-230. In Example 2, a separation membrane dip-coated with DPVDF was prepared in the same manner as in Example 1-1.

[0110] The separator membrane dip-coated in Example 1-1 above was modified to be hydrophilic by reacting it with Jeffamine D-230. First, a Jeffamine D-230 solution was prepared. The solution was prepared by dissolving Jeffamine D-230 in an ethanol solvent at a concentration of 0.80 M. The separator membrane dip-coated in Example 1-1 above was immersed in the Jeffamine D-230 solution for 20 seconds, and then dried at 80°C for 10 minutes. During the immersion and drying process, a Michael addition reaction is induced between the DPVDF coated on the separator membrane and Jeffamine D-230.

[0112] Experimental Example 8. Analysis of FT-IR peaks and water contact angles according to Jeffamine D-230 concentration

[0113] Experimental Example 8 was conducted to analyze FT-IR peaks and water contact angles according to the concentration of Jeffamine D-230. First, a membrane modified with Jeffamine D-230 was prepared by dip-coating with DPVDF in the same manner as in Example 2. However, the Jeffamine D-230 was dissolved in ethanol at concentrations of 0.20, 0.50, or 0.80 M and introduced into the membrane. The manufacturing method was carried out in the same manner as in Example 2. The membrane prepared using 0.20 M of Jeffamine D-230 was named DPVDF-J20, the membrane prepared using 0.50 M of Jeffamine D-230 was named DPVDF-J50, and the membrane prepared using 0.80 M of Jeffamine D-230 was named DPVDF-J80.

[0114] The FT-IR peaks of the above DPVDF-J20, DPVDF-J50, and DPVDF-J80 were analyzed in the same manner as in Experimental Example 3, and the results of analyzing the FT-IR peaks in Experimental Example 8 are shown in Fig. 13A, and the results of analyzing the water contact angle are shown in Fig. 13B.

[0115] As a result of Experimental Example 8, the introduction of Zepamin D-230 can be confirmed through FT-IR peaks, and more specifically, through the increase in NH stretching, NH bending, and CO stretching peaks, it can be seen that Zepamin D-230 was introduced (Fig. 13A). In addition, it was confirmed that the water contact angle decreased as the concentration of Zepamin D-230 increased, indicating that it was modified to be hydrophilic (Fig. 13B).

[0117] Example 3. Preparation of a polymer separation membrane hydrophilically modified by ethylene diamine (EDA).

[0118] Example 3 was carried out to prepare a polymer separation membrane modified to be hydrophilic by dip-coating with DPVDF and reacting with ethylene diamine (EDA). In Example 3, a separation membrane dip-coated with DPVDF was prepared in the same manner as in Example 1-1.

[0119] The separator membrane dip-coated in Example 1-1 above was modified to be hydrophilic by reacting it with ethylene diamine (EDA). First, an ethylene diamine solution was prepared. The solution was prepared by dissolving ethylene diamine at a concentration of 0.75 M in an ethanol solvent. The separator membrane dip-coated in Example 1-1 above was immersed in the ethylene diamine solution for 20 seconds, and then dried at 80°C for 10 minutes. During the immersion and drying process, a Michael addition reaction is induced between the DPVDF coated on the separator membrane and the ethylene diamine.

[0121] Example 4. Preparation of a polymer separation membrane hydrophilically modified by triethylenetetramine (TETA)

[0122] Example 4 was carried out to prepare a polymer separation membrane modified to be hydrophilic by dip-coating with DPVDF and reacting with triethylenetetramine (TETA). In Example 4, a separation membrane dip-coated with DPVDF was prepared in the same manner as in Example 1-1.

[0123] The separator membrane dip-coated in Example 1-1 above was modified to be hydrophilic by reacting it with triethylenetetramine (TETA). First, a triethylenetetramine solution was prepared. The solution was prepared by dissolving triethylenetetramine in an ethanol solvent to a concentration of 0.75 M. The separator membrane dip-coated in Example 1-1 above was immersed in the triethylenetetramine solution for 20 seconds, and then dried at 80°C for 10 minutes. During the immersion and drying process, a Michael addition reaction is induced between the DPVDF coated on the separator membrane and triethylenetetramine.

[0125] Example 5. Preparation of a polymer separation membrane hydrophilically modified by diethylene triamine (DETA).

[0126] Example 5 was carried out to prepare a polymer separation membrane modified to be hydrophilic by dip-coating with DPVDF and reacting with diethylene triamine (DETA). In Example 5, a separation membrane dip-coated with DPVDF was prepared in the same manner as in Example 1-1.

[0127] The separator membrane dip-coated in Example 1-1 above was modified to be hydrophilic by reacting it with diethylene triamine (DETA). First, a diethylene triamine solution was prepared. The solution was prepared by dissolving 0.75 M of diethylene triamine in an ethanol solvent. The separator membrane dip-coated in Example 1-1 above was immersed in the diethylene triamine solution for 20 seconds, and then dried at 80°C for 10 minutes. During the immersion and drying process, a Michael addition reaction is induced between the DPVDF coated on the separator membrane and the diethylene triamine.

[0129] Experimental Example 9. Analysis of FT-IR peaks and water contact angles according to the type of monomer used for hydrophilic modification

[0130] Experimental Example 9 was conducted to analyze FT-IR peaks and water contact angles according to the types of monomers used for hydrophilic modification. Ethylene diamine (EDA), triethylenetetramine (TETA), and diethylene triamine (DETA) were used as the monomer types. Separator membranes were prepared in the same manner as in Examples 3 to 5. The separator membrane prepared in Example 3 was named DPVDF-EDA, the separator membrane prepared in Example 4 was named DPVDF-TETA, and the separator membrane prepared in Example 5 was named DPVDF-DETA.

[0131] The FT-IR peaks and water contact angles of the above DPVDF-EDA, DPVDF-TETA, and DPVDF-DETA were analyzed, and the method of analyzing the FT-IR peaks and water contact angles was carried out in the same manner as in Experimental Example 3. The results of analyzing the FT-IR peaks in Experimental Example 9 are shown in Fig. 14A, and the results of analyzing the water contact angles are shown in Fig. 14B.

[0132] As a result of Experimental Example 9, the introduction of EDA, TETA, and DETA, respectively, can be confirmed through FT-IR peaks. Since the functional groups of EDA, TETA, and DETA react by utilizing the C=C bond of DPVDF, a tendency for the C=C double bond peaks to decrease in DPVDF-EDA, DPVDF-TETA, and DPVDF-DETA was observed compared to the control group DPVDF as the introduction of these functional groups progressed. Additionally, with the introduction of amine groups, NH2-bending (1640, 1580 cm⁻¹) -1 ) and NH2 stretching peak (3400-3300 cm⁻¹ -1It was observed that the water contact angle increased (Fig. 14A). In addition, it was confirmed that the water contact angles of the DPVDF-EDA, DPVDF-TETA, and DPVDF-DETA decreased compared to the DPVDF. More specifically, it was confirmed that the water contact angle of the DPVDF was 121.1°, the water contact angle of the DPVDF-EDA was 93.2°, the water contact angle of the DPVDF-DETA was 98.3°, and the water contact angle of the DPVDF-TETA was 96.4° (Fig. 14B).

[0134] Experimental Example 10. Virus removal effect of a hydrophilically modified polymer membrane

[0135] Experimental Example 10 was conducted to investigate the virus removal effect of a hydrophilically modified polymer membrane. A membrane was prepared by dip-coating with DPVDF in the same manner as in Example 1 and then modifying it to be hydrophilic. The removal effect of the bacteriophage PP7 virus was investigated using the membrane prepared in Example 1.

[0136] In Experimental Example 10 above, the virus used was the bacteriophage PP7 virus (ca. 28 nm), and PBS was used as the buffer. The experimental procedure of Experimental Example 10 above involved conducting a permeation experiment at a pressure of 1 bar, and the experiment was performed after thoroughly washing the membrane with a buffer solution prior to the permeation experiment. The permeation experiment was conducted using a 10 mM PBS solution containing the PP7 virus. The results of Experimental Example 10 above are shown in Table 1 and Figure 15 below.

[0137] As a result of Experimental Example 10, the Log reduction value (LRV) of the membrane prepared in Example 1 was 4.28 to 4.63, and the virus removal rate was confirmed to be 99.99%.

[0139]

[0141] From the foregoing description, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features. In this regard, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

Claim 1 A polymer separation membrane comprising a porous polymer substrate and a coating layer formed on at least one surface of the porous polymer substrate, wherein the coating layer induces a Michael addition reaction between PVDF (Double bond-contained PVDF, DPVDF) containing a double bond and a polymer containing at least one amine group or a monomer containing at least one amine group, and wherein, as the double bond of the DPVDF becomes saturated, a bond is formed between the DPVDF and the polymer containing at least one amine group or the monomer containing at least one amine group. Claim 2 A polymer separation membrane according to claim 1, wherein the porous polymer substrate comprises one or more selected from the group consisting of polyvinylidene fluoride (PVDF); polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP); polysulfone (PSF); polypropylene (PP); polyethylene (PE); and cellulose acetate. Claim 3 A polymer separation membrane according to claim 1, characterized in that the polymer comprising at least one amine group is one or more polymers selected from the group consisting of Jeffamine D-230; linear polyethyleneimine; branched polyethyleneimine (BPEI); polyacrylamide; and polyethylene glycol diamine. Claim 4 A polymer separation membrane according to claim 1, wherein the monomer comprising at least one amine group is one or more monomers selected from the group consisting of Jeffamine EDR 148; Ethylene diamine (EDA); Triethylenetetramine (TETA); Hexamethylenediamine (HMDA); Diaminopropane (1,3-diaminopropane); and Diethylene triamine (DETA). Claim 5 A polymer separation membrane according to claim 1, characterized in that the polymer separation membrane is used for water treatment, virus filters, pretreatment devices for seawater desalination processes, or food purification devices. Claim 6 A method for manufacturing a polymer separation membrane, characterized by comprising: a step of dip-coating a porous polymer substrate with double bond-contained PVDF (DPVDF); and a step of hydrophilizing the dip-coated substrate by immersing it in a solution containing at least one amine group or a monomer containing at least one amine group. Claim 7 A method for manufacturing a polymer separation membrane according to claim 6, characterized in that the method further includes drying and rinsing steps. Claim 8 A method for manufacturing a polymer separation membrane according to claim 6, wherein the porous polymer substrate comprises one or more selected from the group consisting of polyvinylidene fluoride (PVDF); polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP); polysulfone (PSF); polypropylene (PP); polyethylene (PE); and cellulose acetate. Claim 9 A method for manufacturing a polymer separation membrane according to claim 6, wherein the polymer comprising at least one amine group is one or more polymers selected from the group consisting of Jeffamine D-230; linear polyethyleneimine; branched polyethyleneimine (BPEI); polyacrylamide; and polyethylene glycol diamine. Claim 10 A method for manufacturing a polymer separation membrane according to claim 6, wherein the monomer comprising at least one amine group is one or more monomers selected from the group consisting of Jeffamine EDR 148; Ethylene diamine (EDA); Triethylenetetramine (TETA); Hexamethylenediamine (HMDA); Diaminopropane (1,3-diaminopropane); and Diethylene triamine (DETA). Claim 11 A method for manufacturing a polymer separation membrane according to claim 6, wherein the step of dip-coating the porous polymer substrate with double bond-contained PVDF (DPVDF) comprises immersing the porous polymer substrate in a solution containing the DPVDF to dip-coate, and wherein the solution containing the DPVDF is a solution in which the DPVDF is mixed at a concentration of 0.03 to 0.3 wt% in a solvent in which acetone and ethanol are mixed in a weight ratio of 0.8 to 3:

1. Claim 12 A method for manufacturing a polymer separation membrane according to claim 6, wherein the solution containing a polymer containing at least one amine group or a monomer containing at least one amine group is a solution containing branched polyethyleneimine (BPEI) at a concentration of 0.6 to 0.9 M.

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