KR20160080377A - Hollow fiber type Forward Osmosis filtration membrane and the manufacturing method thereby - Google Patents

Abstract

The present invention relates to a hollow fiber type forward osmosis membrane and a manufacturing method thereof. More specifically, the present invention relates to a hollow forward osmosis membrane, comprising: a polyamide layer on an inner periphery of a support layer in the hollow fiber type forward osmosis membrane; an inner skin layer having a support layer in a fine finger like structure; an inner support layer having a multi-layered finger like structure; and an outer skin layer having a sponge like structure, thereby lowering the possibility of leakage occurring in the membrane and having an excellent salt removal performance and flow rates, and to a manufacturing method thereof.

Description

Technical Field [0001] The present invention relates to a hollow fiber type forward osmosis membrane and a manufacturing method thereof,

[0001] The present invention relates to a hollow fiber type positive osmosis membrane and a method of manufacturing the same, and more particularly, to a hollow fiber type positive osmosis membrane and a method of manufacturing the hollow fiber type microfiltration membrane, The present invention provides a separation membrane comprising an inner support layer having a finger-like structure and an outer skin layer having a finger-like structure, thereby lowering the possibility of leakage in the separation membrane, And a hollow fiber type positive osmosis membrane having excellent flow rate and a manufacturing method thereof.

The cleansing membrane is separated by moving osmotic pressure generated by the concentration difference between the two solutions to the high concentration solution through the membrane using the osmotic pressure as a driving force.

Therefore, the osmosis membrane should allow water to flow from the raw water to the inducing solution through the membrane, while maintaining a constant concentration of the inducing solute while maintaining a high osmotic pressure. For this purpose, it is most important that the osmosis membrane has high water permeability in the osmotic direction and that the solute of the inducing solution is not diffused in the reverse osmosis direction. In addition, the manufacture of the osmosis membrane having less membrane contamination should be preceded. Hereinafter, the characteristics of the osmosis membrane should be summarized as follows.

First, in order to minimize the internal concentration polarization and increase the stain resistance, the porosity of the support layer in the quasi-osmosis membrane should be high and the pore bending degree should be low.

Second, in order to increase the flow rate of permeated water, the thickness of the osmosis membrane should be minimized.

Third, a hydrophilic material is used to minimize permeation resistance to water.

Fourth, in order to maintain the induction solution at a high concentration, the solute should not diffuse into the low concentration solution in the high concentration solution.

Conventionally, there has been proposed a method for producing a positive osmotic membrane using cellulose triacetate, which is a hydrophilic material. Specifically, a solution having a concentration of 25 to 75 탆 in thickness and having the same material as that of the support layer is used. (FO) mode using an induction solution, and a high flow rate of the osmosis membrane at a flow rate of 11 gfd. However, it has been reported that the membrane prepared above has a disadvantage in that the induction solution of high concentration diffuses the solute in the direction of the low concentration of raw water. In the raw water condition containing a high concentration of salt such as seawater, Which is difficult to apply in practice.

Conventionally, a polysulfone solution is cast on a nonwoven fabric to prepare a membrane having an ultrafiltration membrane level, and a polyamide reverse osmosis membrane is prepared by interfacial polymerization of a polyfunctional amine and a polyfunctional acid halide on the membrane surface, The membrane was removed and applied to the FO system. As a result of evaluating the physical properties of the membrane in a forward osmosis (FO) mode, a forward osmosis membrane having a salt removal rate of 0.5 gfd and a salt removal rate of 99% or more was proposed. However, since the osmosis membrane has a salt removal rate sufficient to separate high-concentration raw water such as seawater, it has a problem that it is difficult to use the membrane in practice because the flow rate is low.

The separation membrane made of the conventional polysulfone polymer is excellent in mechanical strength, thermal and chemical stability and can be used as a material of the membrane. However, due to the characteristics of the hydrophobic membrane, it is easy to adsorb pollution sources, There was a problem that this was shortened. Accordingly, there has been developed a polyamide laminate film which comprises a hydrophilic polymer in addition to a hydrophilic polymer to form a polyamide layer on a support layer in order to improve the basic physical properties of the film by imparting hydrophilicity.

However, in the conventional hollow fiber type positive osmosis membrane having the above-described structure, when a module is manufactured by including a plurality of hollow fiber type membrane separation membranes, contact between the membrane and the membrane is continued and the membrane is positioned on the surface of the hollow- There is a problem that the polyamide layer is damaged or severely peeled off from the support layer, thereby significantly deteriorating the quality of the hollow fiber membrane module.

In addition, since the adhesion between the hollow-fiber type separators during the manufacture and operation of the module is remarkably increased, the contact between the membranes and thus the damage and / or the detachment of the polyamide layer are accelerated so that the durability is significantly lowered, there was. Furthermore, in order to minimize the above-mentioned problems occurring in the manufacturing process of the separator, the time and effort put into the process have a problem of significantly lowering the workability.

Korean Published Patent Application No. 10-2012-0071495 (Publication date: May 20, 2014) Korean Patent Publication No. 10-2012-0134039 (published on July 17, 2014)

SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the above problems, and it is an object of the present invention to provide a hollow osmosis membrane having a polyamide layer formed on an inner circumferential surface of a supporting layer and having an inner skin layer having a finger- (Finger-like structure) and an outer skin layer having a finger-like structure, thereby lowering the possibility of leakage in the separation membrane and realizing excellent salt removal performance and flow rate There is a purpose.

(1) preparing a spinning solution containing a solvent and a polysulfone-based polymer; (2) simultaneously spinning the spinning solution and the internal coagulating agent through a spinning nozzle equipped with a humidifying chamber, and then immersing the spinning solution in an external coagulating solution to prepare a hollow support; (3) introducing an amine aqueous solution into the hollow support; (4) injecting air into the hollow support into which the amine aqueous solution is injected to remove excess amine aqueous solution; And (5) injecting an interfacial polymerization-forming agent into the hollow support, and drying the hollow support to form a polyamide layer on the inner peripheral surface of the hollow support, wherein in the step (2) Wherein the object passes through a humidifying chamber having a humidity of 80 to 95% and a temperature of 40 to 70 캜 before being immersed in an external coagulating solution.

According to a preferred embodiment of the present invention, in the step (1), the solvent is selected from the group consisting of N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylsulfoxide (DMSO) and dimethylacetamide ). ≪ / RTI >

According to a preferred embodiment of the present invention, in the step (1), the polysulfone-based polymer may include a polysulfone and a sulfonated polysulfone.

According to a preferred embodiment of the present invention, in the step (1), the polysulfone-based polymer may include polysulfone and sulfonated polysulfone in a weight ratio of 8 to 10: 1.

According to a preferred embodiment of the present invention, the solvent and the polysulfone-based polymer in the step (1) may be contained in a weight ratio of 70 to 85:15 to 30.

According to a preferred embodiment of the present invention, in the step (2), the internal coagulant may be mixed with the organic polar solvent and water at a volume ratio of 5: 5 to 9: 1.

According to a preferred embodiment of the present invention, the organic polar solvent may be at least one selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, glycerol and glycerin have.

According to a preferred embodiment of the present invention, in the step (2), the spinning nozzle provided with the humidifying chamber is a multi-tubular spinning nozzle, and the spinning stock solution is discharged to the outer tube of the multi- It can be discharged to the inner tube of the spinning nozzle.

According to a preferred embodiment of the present invention, the temperature of the external coagulating solution in the step (2) may be 30 ° C to 90 ° C.

According to a preferred embodiment of the present invention, the external coagulating solution of step (2) is selected from the group consisting of N-methylpyrrolidone, N, N-dimethylacetamide, dimethylsulfoxide, dimethylformamide, glycerol, And may include one or more solvents selected.

According to a preferred embodiment of the present invention, the distance (air gap) from the spinning nozzle to the external coagulating liquid in the step (2) may be 1 cm to 15 cm.

According to a preferred embodiment of the present invention, in step (3), the amine aqueous solution may be introduced into the hollow support at a rate of 100 to 300 ml / min.

According to a preferred embodiment of the present invention, in the step (5), the interfacial polymerization forming agent may include a polyfunctional acid halide compound and an aliphatic hydrocarbon solvent.

According to a preferred embodiment of the present invention, the interfacial polymerization forming agent may be introduced into the hollow support at a rate of 100 to 300 ml / min in the step (5).

According to a preferred embodiment of the present invention, the polyamide layer in the step (5) may be formed through interfacial polymerization.

Another aspect of the invention is a method of forming a hollow; A polyamide layer formed along the periphery of the hollow; And a support layer formed along the outer periphery of the polyamide layer, wherein the support layer comprises an inner skin layer having a fine finger structure, an inner support layer having a finger-like structure, Sponge like structure, wherein the cross-sectional thickness of the inner support layer is 75 to 99% of the total cross-sectional thickness of the support layer.

According to a preferred embodiment of the present invention, the diameter of the hollow is 600 탆 to 900 탆, the thickness of the support layer is 50 탆 to 300 탆, and the thickness of the polyamide layer is 0.01 탆 to 1 탆 have.

According to a preferred embodiment of the present invention, the fine finger structure of the inner skin layer may have an average transverse length of 0.1 μm to 2 μm and an average transverse length of 1 μm to 10 μm.

According to a preferred embodiment of the present invention, the finger structure of the inner layer among the multiple finger structures included in the inner support layer has an average transverse length of 10 mu m to 30 mu m, an average length of 20 mu m to 60 mu m, Of the multi-layer finger structures included in the inner support layer, the finger structures of the outer layers may have an average transverse length of 10 mu m to 30 mu m and an average length of 30 mu m to 60 mu m.

According to a preferred embodiment of the present invention, the fine finger structure of the outer support layer may have a width of 0.1 μm to 2 μm and an average length of 1 μm to 10 μm.

According to a preferred embodiment of the present invention, the hollow tubular positive osmosis membrane may have an average flow rate of 8 gfd or more and an average specific salt flux (SRSF) of 1 g / L or less.

Another aspect of the present invention provides a positive osmosis membrane module including the hollow fiber type positive osmosis membrane.

[0001] The present invention relates to a hollow fiber type positive osmosis membrane and a method of manufacturing the same, and more particularly, to a hollow fiber type osmosis membrane having a polyamide layer formed on the inner surface of a supporting layer of a hollow fiber type osmosis membrane, , An inner support layer having a finger-like structure, and an outer skin layer having a finger-like structure, thereby reducing the possibility of leakage in the separation membrane, The flow rate can be improved.

In addition, the polyamide layer is formed on the inner surface layer of the hollow fiber, so that the leakage of the polyamide layer can be reduced. Even if a plurality of the separation membranes are included in the module, There is no possibility of damage, and the damage of the polyamide layer is prevented by friction between the hollow fiber type positive osmosis membrane and the like, so that the durability of the module can be remarkably improved and the cycle of the module can be increased accordingly.

1 is a cross-sectional view of a spinning nozzle having a humidification chamber for manufacturing a hollow fiber type positive osmosis membrane according to the present invention.
2 is a cross-sectional view of a hollow fiber type positive osmosis membrane according to a preferred embodiment of the present invention.
3 is a scanning electron microscope (SEM) image of an inner cross section of a hollow fiber type osmosis membrane according to a preferred embodiment of the present invention.
4 is a scanning electron microscope (SEM) image of an outer surface of a support of a hollow fiber type osmosis membrane according to a preferred embodiment of the present invention.
5 is a scanning electron microscope (SEM) image of an inner surface of a support of a hollow fiber type osmosis membrane according to a preferred embodiment of the present invention.

As described above, in the conventional hollow-type positive osmosis membrane, a membrane made of a polyamide layer on the surface of a polysulfone-based polymer may have a crack in the coating layer, resulting in a decrease in durability, In order to minimize the above-mentioned problems, there is a problem that workability is lowered due to time and effort put into the process.

Accordingly, the present invention provides a method for producing a polymer electrolyte membrane, comprising: (1) preparing a spinning solution containing a solvent and a polysulfone-based polymer; (2) simultaneously spinning the spinning solution and the internal coagulating agent through a spinning nozzle equipped with a humidifying chamber, and then immersing the spinning solution in an external coagulating solution to prepare a hollow support; (3) introducing an amine aqueous solution into the hollow support; (4) injecting air into the hollow support into which the amine aqueous solution is injected to remove excess amine aqueous solution; And (5) injecting an interfacial polymerization-forming agent into the hollow support, and drying the hollow support to form a polyamide layer on the inner peripheral surface of the hollow support, wherein in the step (2) The object is passed through a humidification chamber having a humidity of 80 to 95% and a temperature of 40 to 70 캜 before being immersed in an external coagulating solution, thereby solving the above-mentioned problem.

This makes it possible to reduce the possibility of a leak on the surface of the hollow tubular positive osmosis membrane and achieve excellent salt removal performance and flow rate. Hereinafter, the present invention will be described in more detail by step.

In the method of manufacturing a hollow fiber type positive osmosis membrane according to the present invention, the step (1) is a step of preparing a spinning stock solution, which is a raw material used for producing a hollow support, wherein the spinning spinning solution is a solvent and a polysulfone Polymer. At this time, the solvent is preferably at least one selected from the group consisting of N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylsulfoxide (DMSO), and dimethylacetamide , More preferably N-methyl-2-pyrrolidone (NMP). In addition, the polysulfone-based polymer may include polysulfone and sulfonated polysulfone, preferably polysulfone and sulfonated polysulfone in a weight ratio of 8 to 10: 1, and more preferably, Is preferably contained in a weight ratio of 9 to 10: 1.

In this case, the solvent and the polysulfone-based polymer are preferably contained in a weight ratio of 70 to 85: 15 to 30 to prepare a spinning solution. More preferably, the solvent and the polysulfone-based polymer are 80 to 85:15 to 20 It should be included in weight ratio.

In the method of manufacturing a hollow fiber type positive osmosis membrane according to the present invention, in step (2), the spinning liquid and the internal coagulating agent are simultaneously radiated through a spinning nozzle equipped with a humidifying chamber, Thereby producing a support.

The organic coagulant may be an aqueous solution of an organic polar solvent and water. The organic polar solvent may be selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, glycerol and glycerin May be used. The inner coagulant is preferably prepared by mixing an organic polar solvent and water at a volume ratio of 5: 5 to 9: 1, and if the polar solvent is less than 5, there is a problem that eccentricity occurs in the hollow of the membrane produced during spinning If it exceeds 9, solidification of the film occurs slowly, and a support is difficult to form.

In the step (2), the spinning nozzle having the humidifying chamber is a multi-tubular spinning nozzle, and the spinning stock solution may be discharged to the outer tube of the multi-tubular spinning nozzle and the inner coagulant may be discharged to the inner tube of the multi-tubular spinning nozzle .

The radiation emitted through the spinneret passes through a humidification chamber at a humidity of 80-95% and a temperature of 40-70 ° C, preferably at a humidity of 90-95% and a temperature of 50-60 ° C before being immersed in the external coagulating liquid If the humidity and the temperature are out of the above ranges, there is a problem that the hollow support is difficult to be formed from the radiation.

In addition, the radiation emitted from the spinning nozzle is exposed to air before being immersed in the external coagulating solution. At this time, depending on the distance from the spinning nozzle to the external coagulating liquid, that is, the length of the air gap, Can be optimized. Accordingly, the air gap can be 15 cm or less, preferably 1 cm to 15 cm, and more preferably 5 to 10 cm. If the gap between the surface of the external coagulating solution and the spinning nozzle is shortened, the reaction first occurs due to the gases generated from the coagulating water surface before coagulation, resulting in deterioration of the physical properties and the immersion in the external coagulating solution, The surface is formed to be solid and dense to deteriorate the physical properties, particularly the flow rate, so that the interval between the coagulating liquid surface and the spinneret becomes too short. If the air gap length exceeds 15 cm, the surface of the hollow support is humidified by exposure to air for a long time, and the pores existing in the outer support layer are formed in a bulky manner, which is not suitable because the strength of the separation membrane is lowered.

The temperature of the coagulation bath containing the external coagulating liquid is preferably 30 to 90 ° C. If the temperature is less than 30 ° C., the size of the pore size on the external surface of the hollow fiber is remarkably reduced to obtain the desired water permeability If the temperature exceeds 90 ° C, water in the coagulation bath may evaporate and there may be a problem in reproducibility of the membrane.

In the method of manufacturing a hollow fiber type positive osmosis membrane according to the present invention, the step (3) includes the step of injecting an amine aqueous solution into the hollow support, wherein the aqueous amine solution is processed in a subsequent step, A polyamide layer can be formed inside.

The amine aqueous solution is preferably poured into the hollow support at a rate of 100 to 300 ml / min for 0.5 to 2 minutes, more preferably at a rate of 150 to 250 ml / min for 1 to 2 minutes, It can be put into the inside. When the amine aqueous solution is injected into the hollow support at a rate of less than 100 ml / min, the coating solution does not smoothly permeate into the membrane, thereby deteriorating the salt removal performance. When the amine solution exceeds 300 ml / min When the coating solution is injected into the support, excessive coating solution may penetrate and the coating layer may be thickened to deteriorate the flow rate performance.

At this time, the amine aqueous solution includes a polyfunctional amine, and the polyfunctional amine may include at least one of methaphenyldiamine, paraphenyldiamine, orthophenyldiamine, piperazine, alkylated piperidine, and the like.

Specifically, the polyfunctional amine may be a polyamine having two or three amine functional groups per monomer, and may include a primary amine or a secondary amine. As the polyamines, aromatic primary diamine is used as the metaphenylenediamine, paraphenylenediamine, orthophenyldiamine and the substituent. As another example, aliphatic primary diamine and cycloaliphatic primary diamine such as cyclohexenediamine , Cycloaliphatic secondary amines such as piperazine, and aromatic secondary amines. More preferably, the polyfunctional amine is selected from the group consisting of metaphenylenediamine, and the concentration thereof is preferably in the form of an aqueous solution containing 0.5 to 10 wt% of metaphenylenediamine, more preferably 1 to 4 wt% % Aqueous solution.

At this time, the polyfunctional amine may further include a compound containing a hydrophilic group in order to improve the basic properties of the membrane, and it may be contacted with an interfacial polymerization forming agent containing a multifunctional acid halazine compound to form a poly An amide layer can be formed. The compound containing the hydrophilic group may be present in an amount of 0.001 to 8% by weight, more preferably 0.01 to 4% by weight, in the aqueous solution.

The hydrophilic compound which can be added to the aqueous solution containing the polyfunctional amine is a hydrophilic compound having at least one hydrophilic functional group selected from the group consisting of a hydroxyl group, a sulfonated group, a carbonyl group, a trialkoxysilane group, an anion group and a tertiary amino group It may be a hydrophilic compound, more preferably a hydrophilic amino compound.

More specifically, preferred examples of the hydrophilic compound having a hydroxy group include 1,3-diamino-2-propanol, ethanolamine, diethanolamine, 3-amino-1-propanol, -Amino-1-butanol. ≪ / RTI >

The hydrophilic compound having a carbonyl group is selected from the group consisting of aminoacetaldehyde dimethylacetal,? -Aminobutylolactone, 3-aminobenzamide, 4-aminobenzamide and N- (3-aminopropyl) And may be any one or more selected.

Further, the hydrophilic compound containing a trialkoxysilane group may be any one or more selected from the group consisting of (3-aminopropyl) triethoxysilane and (3-aminopropyl) trimethoxysilane.

Examples of the hydrophilic compound having an anionic group include glycine, taurine, 3-amino-1-propenesulfonic acid, 4-amino-1-butenesulfonic acid, 2-aminoethylhydrogensulfate, 3-aminobenzenesulfonic acid, Amino-3-hydroxybenzoic acid, 3-amino-4-hydroxybenzenesulfonic acid, 4-aminobenzenesulfonic acid, 3-aminopropylphosphonic acid, Aminobutane oxidase, 4-aminobutane oxidase, 4-amino-2-hydroxybutyric acid, 4-aminobutyric acid, and glutamic acid. have.

Examples of the hydrophilic compound having one or more tertiary amino groups include 3- (diethylamino) propylamine, 4- (2-aminoethyl) morpholine, 1- - diamino-N-methyldipropylamine and 1- (3-aminopropyl) imidazole.

In the method of manufacturing a hollow fiber type positive osmosis membrane according to the present invention, the step (4) comprises injecting air into the hollow support into which the amine aqueous solution is injected to remove excess amine aqueous solution, , The polyamine layer may be formed on the hollow outer circumferential surface by interfacial polymerization in the subsequent step.

In the method of manufacturing a hollow fiber type positive osmosis membrane according to the present invention, in the step (5), an interfacial polymerization forming agent is injected into the hollow support and dried to form a polyamide layer on the inner peripheral surface of the hollow support as,

The interfacial polymerization forming agent is an interfacial polymerization forming agent containing a polyfunctional acid halide compound, and a polyamide layer may be formed on the inner peripheral surface of the hollow support through interfacial bonding with the amine aqueous solution introduced in the step (3).

The material that reacts with the polyfunctional amine used in forming the polyamide layer of the present invention may be a polyfunctional acid halide, that is, a polyfunctional acyl halide. Preferably, it may be used alone or in a mixed form of trimesoyl chloride, isophthaloyl chloride, 5-methoxy-1,3-isophthaloyl chloride, terephthaloyl chloride and the like. At this time, it is most preferable to use the mixed form in terms of the salt removal rate. The polyfunctional acyl halide may be dissolved in an aliphatic hydrocarbon solvent in an amount of 0.01 to 2% by weight, wherein the aliphatic hydrocarbon solvent is an alkane having 5 to 12 carbon atoms and a structural isomer of a saturated or unsaturated hydrocarbon having 8 carbon atoms Or a cyclic hydrocarbon having 5 to 7 carbon atoms is preferably used. The polyfunctional acyl halide-containing solution preferably dissolves 0.01 to 2% by weight, more preferably 0.05 to 0.3% by weight, of the polyfunctional acyl halide in the aliphatic hydrocarbon solvent.

In a preferred embodiment of the present invention, the interfacial polymerization forming agent may be introduced into the hollow support at a rate of 100 to 300 ml / min in the step (5). The interfacial polymerization initiator is preferably introduced into the hollow support at a rate of 100 to 300 ml / min for 0.5 to 2 minutes, more preferably at a rate of 150 to 250 ml / min for 1 to 2 minutes, Can be introduced into the inside of the support. When the interfacial polymerization forming agent is introduced into the hollow support at a rate of less than 100 ml / min, the coating solution does not smoothly permeate into the membrane, thereby deteriorating the salt removal performance. The excess amount of coating solution penetrates into the inside of the support to form a thick coating layer, thereby deteriorating the flow rate performance.

As described above, the hollow fiber type positive osmosis membrane according to the present invention, which can be manufactured by the above-described manufacturing method, A polyamide layer formed along the periphery of the hollow; And a support layer formed along an outer periphery of the polyamide layer, wherein the support layer comprises an inner skin layer having a finger-like structure, an inner support layer having a finger-like structure, And an outer skin layer having a finger-like structure, wherein the inner supporting layer has a sectional thickness of 75 to 99% of the total sectional thickness of the supporting layer. Hereinafter, the present invention will be described in more detail with respect to each of the constituent elements.

In the hollow fiber type positive osmosis membrane according to the present invention, the diameter of the hollow is 600 탆 to 900 탆, the thickness of the support layer is 50 탆 to 300 탆, and the thickness of the polyamide layer is 0.01 탆 to 1 탆 Lt; / RTI >

If the cross-sectional thickness of the support layer is less than 50 占 퐉, the thickness of the hollow support layer may be too small to ensure mechanical strength. If the cross-sectional thickness of the support layer is less than 50 占 퐉, When the diameter exceeds 300 탆, the mechanical strength can be ensured. However, as the cross-sectional thickness of the hollow fiber becomes thicker and the flow rate decreases or the diameter of the hollow fiber itself becomes larger, The number of the specific osmosis membranes decreases, and accordingly, the effective area of the filtration decreases, which may cause a problem that the efficiency of the module decreases.

The thickness of the polyamide layer formed along the hollow outer periphery is preferably 0.01 탆 to 1 탆. If the thickness of the polyamide layer is less than 0.01 탆, the ability to remove the salt may deteriorate and it may fail to serve as a selective layer. If the thickness exceeds 1 탆, the thickness of the selective layer becomes excessively thick, This can be.

In the hollow fiber type positive osmosis membrane according to the present invention, the supporting layer may include an inner skin layer having a fine finger structure, an inner supporting layer having a finger-like structure, The thickness of the inner supporting layer is preferably 75 to 99%, more preferably 80 to 95% of the total thickness of the supporting layer. The finger structure of the inner supporting layer includes the pores of the elongated finger shape to improve the flow rate of the positive osmosis membrane according to the present invention. When the cross-sectional thickness of the inner support layer is less than 75% of the total cross-sectional thickness of the support layer, the flow rate and the SRSF decrease. When the cross-sectional thickness exceeds 99%, the mechanical strength is lowered.

At this time, the fine finger structure of the inner skin layer preferably has an average transverse length of 0.1 탆 to 2 탆 and an average transverse length of 1 탆 to 10 탆, more preferably an average transverse length of 0.5 탆 to 1.5 탆 , And an average longitudinal length of 3 탆 to 8 탆. When the size of the fine finger structure of the inner skin layer is out of the above range, the flow rate of the support and the FO film and the SRSF performance are drastically deteriorated.

In addition, the finger structure of the inner layer among the multi-layer finger structures included in the inner supporting layer preferably has an average transverse length of 10 mu m to 30 mu m and an average transverse length of 20 mu m to 60 mu m, The length is 15 탆 to 25 탆, and the average length is 30 탆 to 50 탆. The finger structure of the outer layer among the multiple finger structures included in the inner support layer preferably has an average transverse length of 10 mu m to 30 mu m and an average transverse length of 30 mu m to 60 mu m, To 25 mu m, and an average vertical length of 40 mu m to 60 mu m. When the size of the finger structure of the inner support layer is out of the above range, the flow rate and SRSF performance of the support and the osmosis membrane deteriorate rapidly.

In addition, the fine finger structure of the outer supporting layer preferably has an average transverse length of 0.1 탆 to 2 탆 and an average transverse length of 1 탆 to 10 탆, more preferably an average transverse length of 0.5 탆 to 1.5 탆, It is preferable that the average vertical length is 3 탆 to 8 탆. When the size of the fine finger structure of the outer support layer is out of the above range, the flow rate and SRSF performance of the support and the FO film are drastically deteriorated.

The hollow fiber type positive osmosis membrane according to the present invention preferably has an average flow rate of 8 gfd or more and an average SRSF of 1 g / L or less, more preferably an average flow rate of 8 to 20 gfd, an average SRSF of 0.01 to 1 g / L.

Meanwhile, the present invention provides a positive osmosis membrane module including the hollow fiber type positive osmosis membrane according to the present invention. The separator module may include a plurality of hollow tubular positive osmosis membranes. In the hollow tubular positive osmosis membrane according to the present invention, the polyamide layer as the selective layer is formed on the inner surface layer of the hollow fiber, leakage of the polyamide layer can be reduced and even if a plurality of the separation membranes are included in the module, there is no possibility that the polyamide layer is damaged by close contact between the hollow fibers, Can be prevented, and the durability of the module can be remarkably improved, so that the use period of the module can be increased.

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

[ Example ]

Example  One. Positive osmosis Hollow fiber  Preparation of Membrane 1

(1) 18% by weight of polysulfone (PSf, Polysulfone) and 2% by weight of sulfonated polysulfone (SPSf) were mixed in 80% by weight of methyl pyrrolidone and uniformly mixed at 40 占 폚 to prepare a spinning solution.

(2) Using the gear pump, the prepared spinning solution was flowed to the outer tube of the nozzle shown in Fig. 1, and the inner coagulant maintained at 25 캜 was poured into the inner tube of the nozzle to induce the hollow formation. At this time, the internal coagulant contained 60% by weight of methylpyrrolidone (organic polar solvent) and 40% by weight of water. The solutions discharged from the spinning nozzle passed through a humidification chamber having a height of 45 mm provided in the spinning nozzle, and the humidification chamber formed an atmosphere having a humidity of 90% and a temperature of 60 ° C. The distance from the spinning nozzle to the surface of the external coagulating solution was 50 mm, and the distance from the humidifying chamber to the external coagulating solution was 5 mm. The external coagulating liquid contained 100 wt% of water at 60 ° C, and the radiation emitted from the spinning nozzle was continuously immersed in a coagulation bath containing external coagulating liquid to prepare a hollow fiber support.

(3) The prepared hollow support was inserted into a module having a diameter of 10 mm and a length of 100 mm, and both ends were potted with an epoxy adhesive to prepare a module. An aqueous solution containing 2% by weight of metaphenylenediamine (MPD) and 98% by weight of water was flowed into the hollow fiber of the prepared module for 1 minute.

(4) Thereafter, air was injected into the hollow fiber to remove excess amine aqueous solution remaining on the inner surface.

(5), 0.1% by weight of trimesoyl chloride (TMC) was mixed with 99.9% by weight of n-heptane, and the interfacial polymerization forming agent was flowed into the hollow support at a rate of 200 ml / min for 1 minute And then dried in air for one minute to form a polyamide layer by interfacial polymerization. The membrane thus obtained was immersed in a sodium carbonate aqueous solution of 0.2 wt% at room temperature for 2 hours, and then washed with distilled water to prepare a hollow needle-like osmosis membrane.

Example  2. Positive osmosis Hollow fiber  Preparation of Membrane 2

The same procedure as in Example 1 was carried out except that the humecting chamber in the step (2) was provided with an atmosphere of 95% humidity and a temperature of 60 ° C to prepare a hollow fiber type osmosis membrane in the same manner as in Example 1 .

Example  3. Positive osmosis Hollow fiber  Preparation of Membrane 3

A hollow fiber type osmosis membrane was prepared in the same manner as in Example 1, except that in the step (2), the humidifying chamber was provided with an atmosphere having a humidity of 80% and a temperature of 60 ° C .

Comparative Example  One. Positive osmosis Hollow fiber  Preparation of Membrane 1

A hollow fiber type osmosis membrane was prepared in the same manner as in Example 1, except that in the step (2), the humidifying chamber was provided with an atmosphere having a humidity of 75% and a temperature of 60 ° C .

Comparative Example  2. Positive osmosis Hollow fiber  Preparation of Membrane 2

A hollow fiber type osmosis membrane was prepared in the same manner as in Example 1, except that in the step (2), the humidifying chamber was provided with an atmosphere having a humidity of 98% and a temperature of 60 ° C .

Comparative Example  3. Positive osmosis Hollow fiber  Preparation of Membrane 3

A hollow fiber type osmosis membrane was prepared in the same manner as in Example 1, except that a double tube spinning nozzle having no humidifying chamber was used in the step (2).

Comparative Example  4. Positive osmosis Hollow fiber  Preparation of Membrane 4

The procedure of Example 1 was followed except that the polyamide layer was formed on the outside of the hollow support after the step (3), thereby producing a hollow needle type osmosis membrane.

Experimental Example  One.

The performance of the hollow fiber type positive osmosis membrane prepared through the above Examples and Comparative Examples was evaluated and shown in Table 1 below.

1. Membrane flow measurement

Both ends of the coagulated epoxy adhesive were cut to secure a flow path of the hollow fiber membrane so that water could flow through the inner diameter of the hollow fiber membrane prepared above. Then, raw water was caused to flow through the hollow fiber inner diameter, Afterwards, the flow of water from the raw water to the induction solution was induced, and the amount of water per hour was measured by measuring the weight of the induction solution over time. At this time, the induction solution was flowed at a constant flow rate (200 ml / min) using ultrapure water (osmotic pressure of about 100 atm) as raw water using 2M NaCl.

) 측정2. Specific reverse salt flux (SRSF)

) Measure

(2M NaCl) was used as the inductive solution, and the electric conductivity change of the salts introduced into the raw water side (ultrapure water) in the induction solution was measured using ultrapure water (osmotic pressure: about 100 atm) The conductivity of the solution between electrodes with a distance of 1 cm from a certain membrane area was measured using a conductivity meter to evaluate the degree of despreading in units of the change in conductivity per minute (μS / cm).

The result of converting the conductivity value of the membrane area (10 cm ² ) to the conductance value per minute (μS / cm) / min obtained above was substituted into the following equations (1) and (2) Respectively.

[Formula 1]

? / 2.14 = C _NaCl

At this time ,? Is the conductivity value per minute (μS / cm) / min, and 2.14 is the correlation coefficient between the electric conductivity and the concentration. After substituting into the formula 1 to confirm the concentration, it was substituted into the following formula 2.

[Formula 2]

In this case, t is time, C is NaCl concentration, A is membrane area, and V is raw water volume.

Total support thickness
(탆) Inner skin layer thickness
(탆) Inner support layer thickness (탆) Outer skin layer thickness (占 퐉) Thickness of inner support layer / thickness (%) of whole support Within the humidification chamber
Humidity
(%) Within the humidification chamber
Temperature
(° C) Average
flux
(gfd) Average
SRSF
(g / L) Example 1 110 8 96 6 87 90 60 10.6 0.84 Example 2 118 8 102 8 86 95 60 10.8 1.06 Example 3 103 6 88 5 83 80 60 9.1 0.55 Comparative Example 1 112 14 96 11 79 75 60 5.1 0.39 Comparative Example 2 122 5 109 8 89 99.5 60 14.1 11.9 Comparative Example 3 - - - - - - - Eccentricity - Comparative Example 4 110 8 96 6 87 90 60 11.3 2.14

As shown in Table 1, it was confirmed that the average osmotic flow rate of the positive osmosis hollow fiber membrane prepared in Examples 1 to 3 was not less than 9 gfd and the average SRSF was not more than about 1 g / L. However, in the case of the positive osmosis hollow fiber membrane produced in Comparative Examples 1 to 4, Comparative Example 1 produced in an atmosphere having a humidity of less than 80% had a problem that it was difficult to use it as a separator because the flow rate was remarkably low. Comparative Example 2, which is manufactured in Comparative Example 2, has a problem that the average SRSF is so high that it can not function as a separator. In Comparative Example 3 produced without a humidifying chamber, eccentricity occurs. Further, in Comparative Example 4 in which the polyamide layer was formed on the outside of the hollow fiber membrane, it was confirmed that the average SRSF of 1 g / L or more was lowered as a separation membrane, and the polyamide layer could be peeled There is a problem.

Therefore, in the case of the positive osmosis membrane manufactured according to the present invention, when the membrane is manufactured through a humidifying chamber having a humidity of 80 to 95% and a temperature of 40 to 70 ° C, it has an excellent flow rate of 8 gfd or more and an average SRSF of 1 g / . ≪ / RTI >

Experimental Example  2. Preparation according to the invention Positive osmosis  Separator SEM  Measure

The cross section, inner surface and outer surface of the support of the purified osmosis membrane prepared according to the present invention were observed using a scanning electron microscope (SNE-3000, SEC), and the results are shown in Figs.

As shown in FIG. 3, the supporting layer may include an inner skin layer having a finger-like structure, an inner supporting layer having a finger-like structure, and an outer supporting layer having a finger- Skin layer. The fine finger structure of the inner skin layer has a width of about 1 占 퐉 and a length of about 8 占 퐉. Among the multiple finger structures included in the inner support layer, The structure has a length of about 20 mu m and a length of about 40 mu m, and the finger structure of the outer layer has a width of about 20 mu m and a length of about 55 mu m. It was found that the fine finger structure of the outer skin layer had a width of about 1 mu m and a length of about 6 mu m. It was also confirmed that the cross-sectional thickness of the inner supporting layer was about 75 to 99% of the total cross-sectional thickness of the supporting layer.

4 to 5, it was confirmed that the outer surface of the hollow fiber had porosity and the polyamide layer was formed on the inner surface.

10: Internal tube
20: outer tube
30: nozzle housing
40: Humidification chamber
50: External coagulation tank
60: air gap
70: Distance between the coagulation bath and the humidification chamber
100: Internal tube
200: outer tube
300: nozzle housing
400: Humidification chamber

Claims (22)

(1) preparing a spinning solution containing a solvent and a polysulfone-based polymer;
(2) simultaneously spinning the spinning solution and the internal coagulating agent through a spinning nozzle equipped with a humidifying chamber, and then immersing the spinning solution in an external coagulating solution to prepare a hollow support;
(3) introducing an amine aqueous solution into the hollow support;
(4) injecting air into the hollow support into which the amine aqueous solution is injected to remove excess amine aqueous solution; And
(5) introducing an interfacial polymerization-forming agent into the hollow support, and then drying to form a polyamide layer on the inner peripheral surface of the hollow support,
Wherein the radiation emitted through the nozzle in the step (2) passes through a humidifying chamber having a humidity of 80 to 95% and a temperature of 40 to 70 ° C before being immersed in the external coagulating liquid .
The method according to claim 1,
In the step (1), the solvent is at least one selected from the group consisting of N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylsulfoxide (DMSO), and dimethylacetamide Wherein the hollow fiber type positive osmosis membrane is formed by a method comprising the steps of:
The method according to claim 1,
Wherein the polysulfone-based polymer comprises polysulfone and sulfonated polysulfone in the step (1).
The method according to claim 1,
Wherein the polysulfone-based polymer comprises polysulfone and sulfonated polysulfone in a weight ratio of 8 to 10: 1 in the step (1).
The method according to claim 1,
Wherein the solvent and the polysulfone-based polymer are contained in a weight ratio of 70 to 85: 15 to 30 in the step (1).
The method according to claim 1,
Wherein the inner coagulant is mixed with an organic polar solvent and water at a volume ratio of 5: 5 to 9: 1 in the step (2).
The method according to claim 6,
Wherein the organic polar solvent is at least one selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, glycerol and glycerin. Way.
The method according to claim 1,
In the step (2), the spinning nozzle provided with the humidifying chamber is a multi-tubular spinning nozzle,
Wherein the spinning liquid is discharged to an outer tube of a multi-tubular spinning nozzle, and an inner coagulant is discharged to an inner tube of a multi-tubular spinning nozzle.
The method according to claim 1,
Wherein the temperature of the external coagulating solution in step (2) is 30 ° C to 90 ° C.
The method according to claim 1,
The external coagulating solution in the step (2) includes one or more solvents selected from the group consisting of N-methylpyrrolidone, N, N-dimethylacetamide, dimethylsulfoxide, dimethylformamide, glycerol and glycol Wherein the hollow-fiber type positive osmosis membrane is produced by a method comprising the steps of:
The method according to claim 1,
Wherein the distance (air gap) from the spinning nozzle to the external coagulating solution in step (2) is 1 cm to 15 cm.
The method according to claim 1,
Wherein the amine aqueous solution is introduced into the hollow support at a rate of 100 to 300 ml / min in step (3).
The method according to claim 1,
Wherein the interfacial polymerization forming agent comprises a polyfunctional acid halide compound and an aliphatic hydrocarbon solvent in the step (5).
The method according to claim 1,
Wherein the interfacial polymerization forming agent is introduced into the hollow support at a rate of 100 to 300 ml / min in the step (5).
The method according to claim 1,
Wherein the polyamide layer is formed through interfacial polymerization in the step (5).
Hollow;
A polyamide layer formed along the periphery of the hollow; And
And a support layer formed along the periphery of the polyamide layer,
The supporting layer includes an inner skin layer having a finger-like structure, an inner supporting layer having a finger-like structure, and an outer skin layer having a finger-like structure,
Wherein the cross-sectional thickness of the inner support layer is 75 to 99% of the total cross-sectional thickness of the support layer.
17. The method of claim 16,
Wherein the diameter of the hollow is 600 to 900 占 퐉, the thickness of the support layer is 50 to 300 占 퐉, and the thickness of the polyamide layer is 0.01 to 1 占 퐉.
17. The method of claim 16,
Wherein the fine finger structure of the inner skin layer has an average transverse length of 0.1 mu m to 2 mu m and an average transverse length of 1 mu m to 10 mu m.
17. The method of claim 16,
The finger structure of the inner layer among the multiple finger structures included in the inner support layer has an average transverse length of 10 mu m to 30 mu m and an average transverse length of 20 mu m to 60 mu m,
Wherein the finger structure of the outer layer of the multi-layer finger structure included in the inner support layer has an average transverse length of 10 mu m to 30 mu m and an average length of 30 mu m to 60 mu m.
17. The method of claim 16,
Wherein the fine finger structure of the outer support layer has a transverse length of 0.1 탆 to 2 탆 and an average longitudinal length of 1 탆 to 10 탆.
17. The method of claim 16,
Wherein the hollow tubular positive osmosis membrane has an average flow rate of 8 gfd or more and an average specific salt flux (SRSF) of 1 g / L or less.
22. A module for a normal osmosis membrane module comprising a hollow fiber type positive osmosis membrane according to any one of claims 16 to 21.

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