KR20140003086A - Hollow fiber nano filtration membrane and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a hollow fiber nanofiltration membrane and a manufacturing method thereof. The manufacturing method of a hollow fiber type nano-membrane according to the present invention improves physical properties such as water permeability and divalent ion removal rate as a hydrophilic hollow support is bonded to a polyamide layer at an excellent bonding force by forming a hydrophilic hollow support having an asymmetric structure with sponge type pores at the inside of the hollow fiber and finger-shaped pores at the outside of the hollow fiber, making an aqueous amine solution react on the hollow fiber support modified to have hydrophilicity, and interfacial-polymerizing an organic solution containing acyl halide to form a polyamide layer; and has an excellent strength due to a composite membrane structure. Therefore, the hollow fiber nanofiltration membrane according to the present invention is expected to have an energy saving effect as the packing density and the membrane area are larger than the conventional spiral nanofiltration membrane module, which produces more flux in a low pressure. [Reference numerals] (AA) Example 1; (BB) Example 2; (CC) Comparative example 1

Description

Hollow fiber type nanomembrane and its manufacturing method {HOLLOW FIBER NANO FILTRATION MEMBRANE AND MANUFACTURING METHOD THEREOF}

The present invention relates to a hollow fiber nano-membrane membrane and a method for manufacturing the same, and more particularly, to form a hydrophilic hollow fiber support having an asymmetric pore structure, and reacted with an aqueous amine solution on the hydrophilic modified hollow fiber support acyl By interfacially polymerizing the halide-containing organic solution to form a polyamide layer, the hydrophilic hollow fiber support and the polyamide layer have excellent interlayer bonding force, thereby improving water permeability and divalent ion removal rate, and increasing membrane strength due to the composite membrane structure. Relates to an excellent hollow fiber-type nano separator and a method for manufacturing the same.

In general, the nano-filtration membrane (Nano Filtration Membrane) can be obtained a lot of flow rate under a lower pressure than the conventional composite membrane, it is applied to a variety of applications, such as industrial water, drinking water, food manufacturing process. Such a nano-membrane can perform an effective process operation by replacing the advanced oxidation treatment and activated carbon process.

Conventional water treatment membranes include reverse osmosis membranes, ultrafiltration membranes, microfiltration membranes, and the like, and recently, interest in nano-separation membranes that achieve superior performance compared to energy consumption has increased.

Nano-membrane is derived from the concept of nanofiltration (NANO FILTRATION), the main separation target of the nano-membrane is a divalent ion having a solute size of nanometer (nm) or several kinds of monosaccharides and low molecular weight organic materials.

The nano separation membrane is a membrane whose filtration range is present at the boundary between the reverse osmosis membrane and the ultrafiltration membrane, and may be particularly applied in the field of removing minerals from water with low pollution, separating antibiotics, preparing ultrapure water, and washing heavy metals. .

Of course, reverse osmosis membranes can also separate these materials, but for nanometer-specific solutes, the selective separation ability is lower than that of the nano-membrane, and above all, the energy consumption is much higher than that of the nano-membrane process. There is this.

Thus, there is a great deal of interest and research on nano-membrane membranes capable of separating a greater amount of material at a relatively lower operating pressure.

Most nano separators are generally manufactured as flat membranes and mounted in spiral wound modules for ease of manufacture.

In the case of spiral wound modules, the area of the flat membrane that can be mounted in a certain space is very limited, usually about 300 to 1,000 m 2 / m 3.

However, the hollow fiber membrane module has a mounting density of about 3,600 to 36,000 m 2 / m 3 depending on the diameter of the hollow fiber membrane, so that the hollow fiber membrane can be mounted in a module of the same size in an area 10 times larger than the flat membrane.

In spite of these advantages, the hollow fiber membrane is not used as a nano separation membrane because the shear stress due to the flow of the feed liquid on the membrane surface is very large compared to the flat membrane.

Therefore, in order to apply the hollow fiber membrane as a nano separation membrane, a strong bonding force between layers is required in the composite membrane structure composed of the support and the coating layer.

In addition, unlike the flat membrane, since the hollow fiber membrane cannot use a separate support due to its structural features, it cannot implement mechanical strength that can withstand high pressure.

In order to improve this problem, a representative example of the production of hollow fiber membranes using a material having excellent mechanical properties and having an asymmetric structure is a cellulose acetate membrane. However, the cellulose acetate membrane has a low permeation rate, a low salt excretion rate, a high manufacturing cost, and thus cannot be widely used.

In addition, when a membrane is manufactured in a composite membrane structure in which a thin film is laminated on a hollow fiber support to apply an asymmetric membrane, a poor hydrophobic hollow fiber support and the aqueous solution are treated when the hollow fiber support is treated with an aqueous solution containing a reactant. Due to the binding force, treatment with a solution of the organic phase containing other reactants causes defects in the active layer formed by surface polymerization.

As part of the membrane design to meet the requirements of the nano-separation membrane, a method for producing a polyamide composite membrane has been proposed.

Among them, US Patent No. 4,259,183 to J. E. Cadotte discloses a method for producing a composite membrane in which piperazine and trimezoyl chloride / isophthaloyl chloride (TMC / IPC) are reacted.

Starting from the above invention, a number of researches and patent reports aimed at improving the properties of polyamide membranes have been steadily progressing.

As an example, US Pat. No. 4,765,897, US Pat. No. 4,812,270, US Pat. No. 4,824,574 are post-treated with an inorganic strong acid and a rejection enhancer, and US Pat. No. 6,280,853 uses an epoxide material. A post-treatment coating method of a membrane is disclosed.

In addition, US Pat. No. 4,769,148 and US Pat. No. 4,859,384 propose a technique of inducing a flow rate increase by adding a cationic wetting agent to the piperazine layer during membrane preparation.

In US Pat. No. 4,619,767 and US Pat. No. 4,737,325 by Hydranautics of the United States, polyvinyl vinyl is not an interfacial reaction between metaphenylenediamine (MPD) and trimesoyl chloride (TMC) in preparing membranes. The nanoseparation membrane has been reported to produce a composite membrane through an interfacial reaction between an alcohol / amino compound (PVA / amino compound) and trimezoyl chloride (TMC).

In addition, U.S. Patent No. 4,950,404 to Allied-Signal of the United States proposes a membrane having improved water permeability by increasing the flexibility of the support layer by including a polar non-aqueous solvent in the aqueous solution.

In addition, US Pat. No. 6,113,794 discloses a method for preparing a nanoseparation membrane coated with a hydrophilic polymer by using polyacrylonitrile (PAN) as a support and a technology related to a flat membrane-type nanocomposite membrane.

In Japanese Patent No. 2001-212562 by Toyobo Corporation and US Patent No. 2008-0197071 by Kolon Corporation in Korea, piperazine and trimesoyl chloride were added after spinning by adding polyethylene glycol (PEG) to a polysulfone hollow fiber support. Is reacted to disclose a composite membrane in which a polyamide layer is complexed.

However, although the composite membrane designed or manufactured by the aforementioned patent is advantageous in terms of efficiency or energy in the process, the strength, divalent ion removal rate and permeability of the membrane are not good, and thus, there is a difficulty in practical application.

Therefore, the present inventors have made efforts to improve the problems of the conventional hollow fiber-type nano-separation membrane, and as a result, on the hydrophilic hollow fiber support having an asymmetric pore structure, a hollow fiber-type nano-separation membrane composited with a polyamide layer was prepared and its strength, bivalent This invention was completed by confirming the ion removal rate and water permeability improvement.

It is an object of the present invention to provide a hollow fiber nano separator.

Another object of the present invention is to form a polyamide layer on a hydrophilic hollow fiber support, but to provide a method for preparing a hollow fiber-type nanoseparation membrane which improves the bonding force between the support and the polyamide layer.

The present invention provides a hollow fiber type nanoseparation membrane in which a polyamide layer is formed on a hydrophilic hollow fiber support having an asymmetric pore structure.

In the hollow fiber nano-membrane membrane of the present invention, the hydrophilic hollow fiber support has an asymmetric pore structure consisting of sponge-like pores and the hollow fiber outer surface of the finger-shaped pores, the asymmetric pore structure is compared to the hollow fiber cross-section, sponge-like It consists of 5 to 35% of the pores and 65 to 95% of the pores of the finger form.

In addition, the hydrophilic hollow fiber support is 0.1 to 5% by weight of the hydrophilic additive in the hydrophobic polymer, the hydrophobic polymer is selected from the group consisting of polysulfone, polyethersulfone and polyallylethersulfone, or a mixture thereof. In addition, the hydrophilization additive may be selected from the group consisting of sulfonated polysulfone, sulfonated polyethersulfone, and sulfonated polyallylethersulfone, or a mixture thereof.

Hollow fiber type nanoseparation membrane of the present invention meets the physical properties of the bivalent ion removal rate of 80% or more.

The present invention provides a method for manufacturing a hollow fiber-type nano-membrane membrane, 1) the dope solution containing 0.1 to 5% by weight of the hydrophilic additive in the hydrophobic polymer and the internal coagulant for forming the core through the spinning nozzle to expose the air to the coagulation tank Dipping to form a hydrophilic hollow fiber support,

2) the hydrophilic hollow fiber support is immersed in an aqueous amine solution and dried;

3) It provides a method for producing a hollow fiber-type nano separation membrane is carried out by forming a polyamide layer by immersing the support in an acyl halide-containing organic solution.

In the manufacturing method of the hollow fiber-type nano separator of the present invention, the dope solution of step 1) is composed of 5 to 25% by weight of hydrophobic polymer, 0.1 to 5% by weight of hydrophilic additive and a residual amount of polar solvent, wherein the hydrophobic polymer is Polysulfone, polyethersulfone and polyallylethersulfone alone or in a mixture thereof.

In addition, the hydrophilization additive of step 1) uses a sulfonated polysulfone, sulfonated polyethersulfone and sulfonated polyallylethersulfone alone or in combination thereof.

In the method for preparing a hollow fiber nanomembrane of the present invention, the internal coagulant used in step 1) is composed of a mixing ratio of solvent A: non-solvent B 4: 6 to 9: 1.

Wherein solvent A is an organic polar solvent alone or in combination thereof selected from the group consisting of N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide, dimethylformamide, glycerol and glycerin, non-solvent B is water or Ethylene glycol is used.

When discharging the coagulation solution in step 1) is maintained at a temperature of 10 to 50 ℃, it is preferable that the air gap is 10 to 100mm in length during air exposure.

In addition, in the method for producing a hollow fiber-type nano separator of the present invention, the aqueous amine solution in step 2) is 0.1 to 2% by weight of metaphenylenediamine is contained in the polar solvent; Or 0.01 to 2% by weight of tertiary polyamine salt in 0.1 to 2% by weight of metaphenylenediamine; the one contained in the polar solvent is used.

The present invention can provide a hollow fiber-type nano separation membrane having a composite membrane structure in which a polyamide layer is formed on a hydrophilic hollow fiber support.

Through the manufacturing method of the hollow fiber-type nano separator of the present invention, the hollow fiber inner surface is sponge-like pores and hollow fiber outer surface By forming a hydrophilic hollow fiber support having an asymmetric pore structure consisting of finger-shaped pores, and forming a polyamide layer on the hydrophilic modified hollow fiber support with excellent binding force, it has excellent water permeability and divalent ion removal rate, Excellent film strength as a composite film is achieved.

1 is an enlarged photograph of the outermost surface of the hollow fiber-type nano separator prepared according to Example 1, Example 2 and Comparative Example 1 of the present invention 10,000 times,
FIG. 2 is a photograph of an inner surface of the hollow fiber-type nanomembrane prepared according to Example 1, Example 2, and Comparative Example 1 of the present invention at a magnification of 1,000 times; FIG.
FIG. 3 is a photograph of an enlarged cross-sectional view of a hollow fiber nano separator prepared in Example 1, Example 2, and Comparative Example 1 of 50 times.

In order to achieve the above object, the present invention provides a hollow fiber-type nano separation membrane of a composite membrane structure in which a polyamide layer is formed on a hydrophilic hollow fiber support.

1 is a photograph of an enlarged outermost surface of a hollow fiber-type nano separator prepared according to Examples 1, 2 and Comparative Example 1 of the present invention 10,000 times, Figure 2 is Example 1, Example of the present invention The inner surface of the hollow fiber-type nano separator prepared according to Example 2 and Comparative Example 1 is a photograph observed by magnifying 1,000 times, Figure 3 is a hollow fiber type prepared according to Examples 1, 2 and Comparative Example 1 of the present invention It is a photograph observed by enlarging the cross section of the nano separator 50 times.

As a result, the hollow fiber-type nanoseparation membrane of the present invention is a structure in which a polyamide layer is formed on a hydrophilic hollow fiber support having an asymmetric pore structure. In the hydrophilic hollow fiber support, the hollow fiber inner surface is sponge-like pores, It can be seen that the outer surface is an asymmetric pore structure consisting of finger-shaped pores. According to this structure it is possible to implement excellent water permeability.

The asymmetric pore structure of the present invention is preferably composed of 5 to 35% of the pores in the form of sponges, 65 to 95% of the fingers in the form of sponges compared to the hollow fiber cross section. At this time, if the pore area of the finger shape is less than 65%, the permeation flow rate is significantly lowered, and if it exceeds 95%, the pressure resistance is significantly lowered and cannot withstand high pressure.

Therefore, the hollow fiber inner surface made of sponge-like pores can withstand water pressure, and the hollow fiber outer surface made of finger-shaped pores can improve the smooth inflow of water and the water permeability of the membrane.

In addition, the hydrophilic hollow fiber support of the present invention contains 0.1 to 5% by weight of the hydrophilic additive in the hydrophobic polymer, and thus has excellent bonding strength with the polyamide layer formed on the support, thereby resulting in a bivalent ion removal rate of 80% or more. Is improved.

Therefore, according to the structural characteristics of the composite membrane having excellent interlayer bonding strength, the hollow fiber-type nano separator has excellent membrane strength.

Thus, the present invention 1) by discharging the dope solution containing 0.1 to 5% by weight of the hydrophilic additive in the hydrophobic polymer and the internal coagulant for forming the core through the spinning nozzle to expose the air, and then immersed in the coagulation bath to form a hydrophilic hollow fiber support Forming,

2) the hydrophilic hollow fiber support is immersed in an aqueous amine solution and dried;

3) It provides a method for producing a hollow fiber-type nano separation membrane is carried out by forming a polyamide layer by immersing the support in an acyl halide-containing organic solution.

Hereinafter, each manufacturing step will be described in detail.

1: forming a hydrophilic hollow fiber support

Step 1) in the preparation method of the present invention is a step of forming a hydrophilic hollow fiber support, the dope solution as the raw material composition of the support is 5 to 25% by weight of hydrophobic polymer, 0.1 to 5% by weight of hydrophilization additive and the remaining amount of polar solvent Is done.

At this time, the hydrophobic polymer may be any polymer having an aromatic monomer unit as a component, preferably a polysulfone polymer.

Polysulfone-based polymers have very stable characteristics due to electrostatic attraction by resonance electrons between aromatic groups around the -SO ₂ group, so they can have stability over a wide temperature range, chemical resistance, various pore sizes, and mechanical strength great. At this time, the polysulfone polymer has a molecular weight of 50,000 or more, preferably 50,000 to 1,000,000, more preferably 50,000 to 300,000.

As an example of the polysulfone-based polymer, polysulfone, polyethersulfone and polyallylethersulfone may be used alone or a copolymer or a modification of these polymers or a mixture thereof.

Accordingly, the polysulfone-based polymer is preferably contained in 5 to 25% by weight in the dope solution, if less than 5% by weight, the viscosity of the polymer solution is weakened, the strength and physical properties of the prepared porous membrane tends to decrease. On the other hand, if it exceeds 25% by weight, the viscosity becomes stronger, which makes the film formation difficult, which is not preferable because the thickness of the produced film increases and the average pore size decreases.

As another composition used in the dope solution of the present invention, the hydrophilization additive is to use a sulfonated polysulfone polymer represented by the following formula (1).

Formula 1

In the embodiment of the present invention, a polysulfone polymer, containing sulfonated polysulfone is described as a preferable example, by employing the same material of the polymer, to improve the binding force between the hollow fiber support and the polyamide coating layer and improve the water permeability Can be improved.

Accordingly, preferred hydrophilic additives are those used alone or in combination thereof selected from the group consisting of sulfonated polysulfones, sulfonated polyethersulfones and sulfonated polyallylethersulfones. At this time, it is preferable that the hydrophilization additive contains 0.1 to 5% by weight in the dope solution. If the content is less than 0.1% by weight, the hydrophilic effect of the support is insufficient, and if the content exceeds 5% by weight, the strength and physical properties of the membrane This decreases.

The polar solvent used in the dope solution of the present invention is not particularly limited as long as it can dissolve the polymer and additives uniformly and completely at room temperature to 150 ° C. or lower without forming a precipitate, but preferably N-methyl-2-pyrrolidone , Dimethylformamide, dimethylsulfide and dimethylacetamide alone or mixtures thereof may be used.

In the manufacturing method of the hollow fiber-type nano separator of the present invention, the internal coagulant (core solution) used in step 1) is composed of a solvent A: non-solvent B mixing ratio of 4: 6 to 9: 1.

The solvent A is an organic polar solvent alone or in a mixed form thereof selected from the group consisting of N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide, dimethylformamide, glycerol and glycerin, and the non-solvent B is water or ethylene Use glycol. More preferably, a mixed solution of N-methylpyrrolidone: water is used.

When the organic polar solvent (solvent A) ratio is less than 4, many pore forms of beads are formed or pores having an undesirable structure in terms of internal membrane contamination are formed. If it exceeds 9, phase transition of the dope solution is not smoothly performed.

The core solution is the inner surface of the hollow fiber membrane, ie inside the hollow fiber, until the solidification of the outer surface of the hollow fiber membrane by the external coagulant in the air gap, which is the section between the spinning nozzle and the external coagulant in the coagulation tank. By coagulation, the structure of the cross-section of the hollow fiber membrane is formed to form an asymmetrical structure in which the pore size increases from the outer surface to the inner surface. As the dope solution of the spinning nozzle is discharged, pores are formed by the internal coagulant contacting therein, thereby obtaining hollow fibers.

Therefore, it is preferable that the internal coagulant of the present invention is maintained at 10 to 50 ° C. at the time of discharging. If the internal coagulant is less than 10 ° C., hollow formation is impossible. This occurs, resulting in a failure of the hollow fiber separator.

The dope solution and the internal coagulant are respectively solidified by dipping the solution discharged through the spinning nozzle into the external coagulant to form a hollow fiber-type nano-membrane support. At this time, the external coagulant is water.

In the manufacturing method of the hollow fiber nano-membrane membrane of the present invention, by controlling the distance (air gap) to the surface of the external coagulating solution of the coagulation bath in the solution discharged from the spinning nozzle in step 1), to control the micropore size and physical properties of the membrane Can be.

Preferred air gap lengths are from 10 to 100 mm. At this time, if the distance from the discharged solution to the surface of the external coagulating solution of the coagulation bath is less than 10 mm, the distance is too close to cause coagulation at the nozzle portion, which causes defects in the hollow fiber. Occurs or eccentricity occurs.

Step 1) of the present invention may further include a washing process to remove the remaining solvent and the organic matter contained in the solvent inside and outside the membrane of the hydrophilic hollow fiber support. Water is preferably used as the washing liquid, and the washing time is not particularly limited, but at least one day or more and five days or less is preferable.

2: immersion in aqueous amine solution

In the production method of the present invention, step 2) is a step of immersing the hydrophilic hollow fiber support in an amine aqueous solution and then removing the excess aqueous solution and drying.

The polyamide layer used in the present invention is generally formed by interfacial polymerization using a material that reacts with a polyamine and a polyamine, wherein the polyamine is a material having 2 to 3 amine functional groups per monomer. Secondary amines.

As examples of the polyamines, aromatic primary diamines are used as metaphenylenediamines, paraphenylenediamines and substituents. In another example, cycloaliphatic primary diamines such as aliphatic primary diamines and cyclohexene diamines, such as piperazine Cycloaliphatic secondary amines, aromatic secondary amines and the like are used.

Thus, the aqueous amine solution of step 2) is 0.1 to 2% by weight of metaphenylenediamine is contained in the polar solvent; Or 0.01 to 2% by weight of tertiary polyamine salt in 0.1 to 2% by weight of metaphenylenediamine; the one contained in the polar solvent is used.

The pH of the aqueous amine solution is preferably adjusted in the range of 7 to 10, wherein the pH can be adjusted by putting a basic substance, but includes an amine salt which can act as an acid acceptor in one or more amine groups in the amine solution. In that case, it is not necessary to add a basic substance.

In the present invention, the amine salt included in the aqueous amine solution is a reactant of a strong acid with a tertiary polyamine, wherein the polyamine has n tertiary amine groups, and reacts with a strong acid at a molar ratio of 1: 1 or more and 1: n or less. .

The above tertiary polyamine salt plays a role of pore formation of the polyamide membrane, thereby improving the flow rate and promoting the interfacial reaction by acting as an acid acceptor of the acid generated during the interfacial reaction.

Examples of the strong acid are aromatic sulfonic acid, aliphatic sulfonic acid, cyclo aliphatic sulfonic acid, trifluoroacetic acid, nitric acid, hydrochloric acid, sulfonic acid and mixtures thereof, and are used. Tertiary polyamines include 1,4-diazabicyclo [2,2,2,] octane (DABCO), 1,8-diazabicyclo [5,4,0] undec-7-ene (DBU), 1, 5-diazabicyclo [4,3,0] non-5-ene (DBN), 1,4-dimethylpiperazine, 4- [2- (dimethylamino) ethyl] morpholine, N, N, N ' , N ',-tetramethylethylenediamine, N, N, N', N ',-tetramethyl-1,3-butanediamine, N, N', N ', -tetramethyl-1,4-butanediamine ( TMBD), N, N, N ', N',-tetramethyl-1,3-propanediamine, N, N, N ', N',-tetramethyl-1,6-hexanediamine (TMHD), 1, 1,3,3, -tetramethylguanidine (TMGU), N, N, N ', N',-pentamethyldiethylenetriamine and mixtures thereof. In addition to the tertiary polyamine salt, one or two or more polar solvents may be added to the polyfunctional amine aqueous solution, and as the polar solvent, an ethylene glycol derivative, a propylene glycol derivative, a 1,3-propanediol derivative, and a sulfoxide may be prepared. Side derivatives, sulfone derivatives, nitrile derivatives, ketone derivatives, urea derivatives, and mixtures thereof, and the like, which also serve to increase the flow rate of the resulting membrane.

Examples of the ethylene glycol derivatives include 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, di (ethylene glycol) -t-butylmethyl ether, di (ethylene glycol) hexyl ether , (2-methoxy ethyl) ether, (2-ethoxyethyl) ether, and the like, and examples of 1,3-propane diol include 1,3-heptane diol, 2-ethyl-1,1-hexanediol, 1 , 3-hexanediol, 1,3, -pentanediol and the like.

As the sulfoxide derivative used in the present invention, dimethyl sulfoxide, tetramethylene sulfoxide, butyl sulfoxide, methylphenyl sulfoxide and the like are useful, and sulfone derivatives such as dimethyl sulfone, tetramethylene sulfone and butyl sulfone are useful.

In the present invention, the nitrile derivative is preferably selected from the group consisting of acetonitrile and propionitrile, and urea derivatives include 1,3-dimethyl-2-imidazolidinnan, and ketone derivatives include acetone and 2- Butanone, 2-hexanone, 3-hexanone, 3-pentanone, cyclohexanone, cyclopentanone and the like.

The total content of such polar solvent alone or in an aqueous solution of two or more mixed solvents is in the range of 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight.

After immersing the hydrophilic hollow fiber support prepared in step 1 on the aqueous solution of amine of step 2), it is preferable to immerse for more than 1 minute and 12 hours or less, and if less than 1 minute, If not sufficiently bonded, the interfacial polymerization occurs nonuniformly, and if it exceeds 12 hours, the amine aqueous solution is not preferable because the reaction proceeds in the air and the physical properties are significantly reduced.

3: immersing in an acyl halide containing organic solution to form a polyamide layer

In the manufacturing method of the present invention, step 3) is a step of forming a polyamide coating layer by immersing in an organic solution containing acyl halide after removing the excess amine aqueous solution on the support surface.

The aromatic polyfunctional acyl halides contained in the organic solution used in the present invention are used alone or in combination thereof. Preferably, the polyfunctional acyl halides are trimesoyl chloride, isophthaloyl chloride, and 1,3,5-cyclo Hexanetricarbonyl chloride, 1,2,3,4-cyclohexanetetracarbonyl chloride can be used. At this time, preferable content is 0.005 to 5 weight%, More preferably, it is 0.01 to 0.5 weight%.

At this time, the aliphatic hydrocarbon solvent should be capable of dissolving 0.1-1% of the polyfunctional acyl halide, should not participate in the interfacial polymerization reaction, have no chemical bond with the acyl halide, and should not be used to damage the support.

Thus, the preferred aliphatic hydrocarbon solvent may be a mixture of structural isomers of n-alkanes having 5 to 12 carbon atoms and saturated or unsaturated hydrocarbons having 8 carbon atoms, or cyclic hydrocarbons having 5 to 7 carbon atoms.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to these examples.

≪ Example 1 >

20% by weight of polysulfone (PSf) was mixed with 79% by weight of dimethyl formamide (DMF) and dissolved under 40 ° C, and then 1% by weight of sulfonated polysulfone (SPSf) was uniformly added. Mixing prepared a dope solution.

The prepared dope solution was flowed into the nozzle maintained at 20 ° C. using a gear pump, and the internal coagulant maintained at room temperature was flowed into the nozzle to induce hollow formation. The solutions discharged from the spinning nozzle were continuously immersed in a coagulation bath made of water at room temperature to prepare a hollow fiber support. At this time, the distance (air gap) from the spinning nozzle to the surface of the external coagulant was 30 mm.

The prepared hollow support was immersed in an aqueous amine solution mixed with 2% by weight of metaphenylene diamine (MPD) and 98% by weight of water for 1 hour, and then taken out to remove excess amine aqueous solution on the surface. Thereafter, 0.1% by weight of trimesoyl chloride (TMC) was immersed in an organic solution mixed and prepared in 99.9% by weight of n-heptane, followed by drying in air for 1 minute to form a polyamide layer by interfacial polymerization.

The membrane obtained above was immersed in 0.2% by weight aqueous sodium carbonate base solution at room temperature for 2 hours, and then washed with distilled water to prepare a hollow fiber nano-membrane.

<Example 2>

The hollow fiber support prepared in Example 1 was prepared with 1.5% by weight of metaphenylenediamine (MPD), 0.8% by weight of N, N, N ', N'-tetramethyl-1,6-hexadiamine (TMHD), Example 1 and 1 except that it was immersed in 1% by weight of toluenesulfonic acid (TSA), an aqueous amine solution containing 0.2% by weight of 2-ethyl-1,3-hexanediol (EHD) as a polar solvent for 1 hour. In the same manner to prepare a hollow fiber-type nano separator.

&Lt; Comparative Example 1 &

Except 21% by weight of polysulfone (PSf) was mixed with 79% by weight of dimethyl formamide (DMF) to prepare a hollow fiber support using a dope solution dissolved under 40 ° C. In the same manner as in Example 1, a hollow fiber nano separator was prepared.

Experimental Example 1 Measurement of Permeation Flow Rate

For the hollow fiber-type nano separators prepared in Examples 1 and 2 and Comparative Example 1, the permeation flux was measured through a hollow fiber evaluator (Woongjin Chemical Co., Ltd.) and the results are shown in Table 1 below. At this time, the performance of the nano-membrane was measured at 25 ℃, 10bar using a magnesium sulfate (MgSO ₄ ) aqueous solution of a concentration of 2,000ppm.

Experimental Example 2 Measurement of Divalent Ion Removal Rate

For the hollow fiber-type nano separators prepared in Examples 1 and 2 and Comparative Example 1, the divalent ion removal rate was measured through a hollow fiber evaluator (Woongjin Chemical Co., Ltd.), and the results are shown in Table 1 below. At this time, the performance of the nano-membrane was measured at 25 ℃, 10bar using a magnesium sulfate (MgSO ₄ ) aqueous solution of a concentration of 2,000ppm.

As shown in Table 1, in the case of the hollow fiber-type nano separation membrane prepared in Example 1 and Example 2, the divalent ion removal rate is significantly improved compared to the nano separation membrane made of a conventional polysulfone-based hollow fiber of Comparative Example 1.

That is, the conventional polysulfone-based hollow fiber type nanoseparation membrane of Comparative Example 1 has high permeation flux while low physical property of divalent ion removal. On the other hand, in the hollow fiber type nanoseparation membranes of Examples 1 and 2 of the present invention, the polyamide layer is formed on the hydrophilic hollow fiber support to improve the interlayer bonding force, thereby significantly reducing the permeation flux and significantly reducing the divalent ion removal rate. The result of improvement was confirmed.

These results can be confirmed that in the hollow fiber-type nano separation membrane of Examples 1 and 2 of the present invention, the bonding force between the support and the polyamide layer was excellent.

In addition, in the process of manufacturing a polyamide layer in Example 2, by adding a tertiary polyamine salt compound and a polar solvent to the amine aqueous solution, it is possible to improve the divalent ion removal rate and permeation flow rate than the hollow fiber type nano separator prepared in Example 1 there was.

Experimental Example 3 Surface Observation of Membrane

The hollow fiber-type nano separators prepared in Examples 1 and 2 and Comparative Example 1 were observed by enlarging the surface of the membrane using SEM (Scanning Electron Microscope: Model of Nanoeye).

FIG. 1 is a photograph of an enlarged outermost surface of a hollow fiber-type nano separator prepared according to Example 1, Example 2, and Comparative Example 1 of 10,000 times, confirming the coating surface of the polyamide layer. Thus, the surfaces of Examples 1 and 2 were observed to be dense and uniform, while the surface of the polyamide layer of Comparative Example 1 was relatively uneven.

FIG. 2 is a photograph of a magnification of 1,000 times the inner surface of the hollow fiber-type nanomembrane prepared according to Examples 1, 2 and Comparative Example 1 of the present invention, and more specifically, as the inner surface of the hollow fiber support, Examples 1 and 2 composed of hollow fiber supports had pores uniformly arranged on the surface, whereas Comparative Example 1 confirmed a dense surface on which no pores were observed.

FIG. 3 is a photograph of an enlarged cross-sectional view of a hollow fiber-type nano separator prepared according to Examples 1, 2, and Comparative Example 1 of the present invention by 50 times, and the cross sections of Examples 1 and 2 are hollow fiber supports. In terms of structure, the inner surface of the hollow fiber was a dense sponge-like pore structure, while the outer surface of the hollow fiber was observed as an asymmetric structure as a finger-shaped pore structure, and a polyamide layer was formed on the outermost side of the membrane.

On the other hand, in the cross section of Comparative Example 1, eccentricity was formed, and it was observed that the bond between polyamide layers formed on the support was poor. These results support the low divalent ion removal rate of Comparative Example 1.

As described above, the present invention provides a hollow fiber-type nanoseparation membrane having a composite membrane structure in which a polyamide layer is formed on a hydrophilic hollow fiber support.

In the present invention, the hollow fiber inner surface is sponge-shaped pores and hollow fiber outer surface From the manufacturing method of forming a hydrophilic hollow fiber support having an asymmetric pore structure composed of finger-shaped pores, and forming a polyamide layer with excellent binding force on the hydrophilic modified hollow fiber support, water permeability and divalent ion removal rate It provided an excellent hollow fiber nano separator.

In addition, the manufacturing method of the present invention is a means for improving the divalent ion removal rate, by further adding a tertiary polyamine salt compound to the aqueous amine solution to optimize the manufacturing method to maintain the proper properties for the nano-membrane process and permeation flux Can be improved.

The hollow fiber-type nano separator manufactured from the manufacturing method of the present invention has a larger packing density than the conventional spiral wound nano separator module and has a large membrane area, thereby producing a large flow rate under low pressure, thereby reducing energy consumption. It can be used in a wide range of fields such as seawater desalination pretreatment, food manufacturing process, and concentration process, and can be expected to increase process utility and reduce treatment cost.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (15)

On a hydrophilic hollow fiber support having an asymmetric pore structure,
Hollow fiber type nano separator formed with a polyamide layer. According to claim 1, wherein the hydrophilic hollow fiber support is characterized in that the hollow fiber nano-membrane membrane, characterized in that the inner surface of the hollow fiber has an asymmetric pore structure consisting of sponge-like pores and the hollow-fiber outer surface of the finger-shaped pores. The hollow fiber nano-membrane of claim 2, wherein the asymmetric pore structure is made of 5 to 35% of sponge-like pores and 65 to 95% of finger pores. According to claim 1, wherein the hydrophilic hollow fiber support is characterized in that the hollow fiber-type nano-separation membrane, characterized in that the hydrophobic polymer contains 0.1 to 5% by weight of a hydrophilic additive. The hollow fiber-type nanoseparation membrane of claim 4, wherein the hydrophobic polymer is selected from the group consisting of polysulfones, polyethersulfones, and polyallylethersulfones, or a mixture thereof. The hollow fiber type according to claim 4, wherein the hydrophilic additive is selected from the group consisting of sulfonated polysulfone, sulfonated polyethersulfone, and sulfonated polyallylethersulfone, or a mixture thereof. Nano separator. The method of claim 1, wherein the hollow fiber nano-membrane divalent ion removal rate of the hollow fiber-type nano separation membrane, characterized in that to meet more than 80%. 1) The dope solution containing 0.1 to 5% by weight of the hydrophilic additive in the hydrophobic polymer and the internal coagulant for core formation are discharged through a spinning nozzle, followed by air exposure, and then immersed in a coagulation bath to form a hydrophilic hollow fiber support.
2) the hydrophilic hollow fiber support is immersed in an aqueous amine solution and dried;
3) A method of manufacturing a hollow fiber-type nanoseparation membrane, which is performed by forming a polyamide layer by immersing the support in an acyl halide-containing organic solution. The method of claim 8, wherein the dope solution of step 1) comprises 5 to 25 wt% of a hydrophobic polymer, 0.1 to 5 wt% of a hydrophilic additive, and a residual polar solvent. The method of claim 8, wherein the hydrophobic polymer is selected from the group consisting of polysulfone, polyethersulfone and polyallylethersulfone or a mixture thereof, and the hydrophilized polymer is sulfonated polysulfone, sulfonated polyether Method for producing the hollow fiber-type nano-separation membrane, characterized in that the sole or mixed form selected from the group consisting of sulfone and sulfonated polyallyl ether sulfone. The method of claim 8, wherein the internal coagulant of step 1) is made of a mixing ratio of solvent A: non-solvent B 4: 6 to 9: 1. 12. The organic polar solvent according to claim 11, wherein the solvent A is selected from the group consisting of N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide, dimethylformamide, glycerol and glycerin, or an organic polar solvent thereof. Method for producing the hollow fiber-type nano separation membrane. The method of claim 8, wherein the temperature of the coagulating liquid in step 1) is maintained at 10 to 50 ° C. 10. The method of claim 8, wherein the air gap of the air exposure of step 1) has a length of 10 to 100mm, characterized in that the hollow fiber-type nano separator manufacturing method. The method of claim 8, wherein the aqueous amine solution of step 2) is 0.1 to 2% by weight of metaphenylenediamine is contained in the polar solvent; Or 0.1 to 2 wt% of a tertiary polyamine salt in 0.1 to 2 wt% of metaphenylene diamine;

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