KR102075192B1 - Composition for interfacial polymerizing polyamide, method for preparing water treatment separation membrane using the same, and water treatment separation membrane and water treatment module - Google Patents

Abstract

The present application is an amine compound; And a polyamide interfacial polymerization composition comprising a single molecule having a nanoporous structure, a method for producing a water treatment membrane using the same, and a water treatment membrane.

Description

COMPOSITION FOR INTERFACIAL POLYMERIZING POLYAMIDE, METHOD FOR PREPARING WATER TREATMENT SEPARATION MEMBRANE USING THE SAME, AND WATER TREATMENT SEPARATION MEMBRANE AND WATER TREATMENT MODULE}

The present specification relates to a composition for polyamide interfacial polymerization and a method for producing a water treatment membrane using the same. In addition, the present disclosure relates to a water treatment separator prepared using the polyamide interfacial polymerization composition and a water treatment module including the water treatment separator.

Osmotic phenomenon is the movement of a solvent through a membrane from a solution of low solute concentration to a high solution between two solutions separated by a semi-permeable membrane. Is called osmotic pressure. By applying an external pressure higher than the osmotic pressure, the solvent moves to a solution having a lower concentration of solute. This phenomenon is called reverse osmosis. Using the reverse osmosis principle, a pressure gradient can be used as a driving force to separate various salts and organic materials through the semipermeable membrane. The water treatment membrane using the reverse osmosis phenomenon is used to separate the material of the molecular level, remove the salt from the brine or sea water to supply household water for construction, industrial use.

Representative examples of such water treatment separation membranes include polyamide-based water treatment separation membranes, and polyamide-based water treatment separation membranes are manufactured by a method of forming a polyamide active layer on a microporous layer support. A sulfonic layer is formed to form a microporous support, and the microporous support is immersed in an m-phenylene diamine (mPD) aqueous solution to form an mPD layer, which is then trimesoyl chloride (TriMesoyl Chloride, TMC) It is manufactured by the method of forming a polyamide layer by immersing in an organic solvent and making an mPD layer contact with TMC and interfacially polymerizing.

In order to increase the permeate flow rate of the water treatment membrane, a method of controlling the internal porosity of the polymer membrane by adjusting the amount of crosslinking of the polymer chain has been attempted. For example, the amount of crosslinking of the polymer chain can be adjusted by inhibiting interfacial polymerization of the polyamide using an additive. However, when increasing the permeate flow rate through the control of the amount of crosslinking, there is a problem in that the salt removal rate is lowered relatively, and thus there is a limitation in increasing the permeate flow rate.

Separation and Purification Technology 120 (2013) 328-340 Journal of Applied Polymer Science, 2013, DOI: 10.1002 / APP.38667

The present application is to provide a water treatment separation membrane having improved flux by adding a single molecule having a nanoporous structure when forming a polyamide layer of the water treatment separation membrane.

One embodiment of the present specification is an amine compound; And it provides a composition for polyamide interfacial polymerization comprising a single molecule having a nanoporous structure.

According to yet an embodiment of the present disclosure, the single molecule having the nanoporous structure is a cyclodextrin molecule.

Another embodiment of the present specification comprises the steps of preparing a porous support; And forming a polyamide active layer on the porous support using the polyamide interfacial polymerization composition described above.

According to one embodiment, the composition for polyamide interfacial polymerization comprises an amine compound and a single molecule having a nanoporous structure, and the polyamide active layer by interfacial polymerization by contacting the polyamide interfacial polymerization composition with an acyl halide compound To form.

Another embodiment of the present specification is a porous support; And a polyamide active layer provided on the porous support, and a structure derived from a single molecule having a nanoporous structure is introduced into the polyamide main chain of the polyamide active layer.

According to the embodiments described herein, by introducing a single molecule having a nanoporous structure at the time of interfacial polymerization of the polyamide layer, molecular nano-pores are introduced into the polyamide membrane during the synthesis of polyamide without controlling the amount of crosslinking. can do. By controlling the nanopores of the molecules to be added, it is possible to control the size of the nanochannels of the final water treatment membrane. By introducing nanopores larger than water molecules and smaller than ions, it is possible to secure a water molecule permeation path, thereby significantly increasing the permeate flow rate of the water treatment membrane.

1 illustrates a cyclodextrin molecular structure with nanopores.
FIG. 2 is a schematic diagram showing that voids in a cyclodextrin molecule serve as a water molecule transport channel. FIG.

In this specification, when a member is located "on" another member, this includes not only when one member is in contact with another member but also when another member exists between the two members.

In the present specification, when a part "includes" a certain component, this means that the component may further include other components, except for the case where there is no description to the contrary.

One embodiment of the present specification is an amine compound; And it provides a composition for polyamide interfacial polymerization comprising a single molecule having a nanoporous structure.

A single molecule having a nanoporous structure means that a pore having a diameter of 0.1 to 10 nm is present through which a single molecule penetrates the molecule.

Monomolecules having the nanoporous structure include cyclodextrin molecules. Cyclodextrin molecules include alpha-cyclodextrin, beta-cyclodextrin, gamma-cyclodextrin, and one or two or more thereof may be used. 1 illustrates a cyclodextrin molecular structure with nanopores. It is preferred that these cyclodextrin molecules have a structure in which at least one hydroxy functional group is replaced with one or more amine substituents in order to participate in interfacial polymerization. For example, the cyclodextrin molecular structure having an amine functional group may include a structure represented by the following Chemical Formula 1 or 2.

 [Formula 1]

[Formula 2]

In Chemical Formulas 1 and 2,

Parentheses [] indicate glucose units contained within cyclodextrins,

m is an integer of 1 or 2,

n is an integer of 6 or more as the number of units of glucose of cyclodextrin,

A is an alkylene group having 1 or more carbon atoms,

Dashed line means the connection between glucose units.

For example, A is an alkylene group having 1 to 10 carbon atoms.

In Formula 1, when the glucose unit containing an amine group is 2 or more (m is 2 or more), these may be directly bonded, but not limited thereto, and do not include an amine group between glucose units containing an amine group. Units may be combined.

In the molecular structure of the cyclodextrin, it is possible to control the size of the nano-pores according to the number of glucose units (n), it is possible to select the molecule according to the type of removal ions. For example, in the structures of Chemical Formulas 1 and 2, when n is 6, α-cyclodextrin, when n = 7, β-cyclodextrin, and when n = 8, γ-cyclodextrin.

According to one embodiment, the single molecule having the nanoporous structure in the composition for polyamide interfacial polymerization may be included in an amount of 0.01 to 20% by weight, preferably 0.01 to 5% by weight, based on 100% by weight of the total composition. The amine compound is not limited as long as it can be used for polymerization of polyamide, but specific examples include m-phenylenediamine (mPD), p-phenylenediamine (PPD), and 1,3,6-benzenetriamine (TAB ), 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 3-chloro-1,4-phenylene diamine or mixtures thereof may be preferably used. The content of the amine compound may be 0.1 wt% or more and 20 wt% or less with respect to 100 wt% of the composition.

The acyl halide compound is not limited as long as it can be used for the polymerization of the polyamide, but is an aromatic compound having 2 to 3 carboxylic acid halides as a specific example, and may include trimezoyl chloride, isophthaloyl chloride and terephthaloyl. One or a mixture of two or more selected from the group of compounds consisting of chlorides may be preferably used. The amount of the acyl halide compound may be 0.05 wt% or more and 10 wt% or less with respect to 100 wt% of the composition.

For example, when the composition for polyamide interfacial polymerization contains an amine compound, the composition may be water, acetone, dimethyl sulfoxide (DMSO), 1-methyl-2-pyrrolidinone (NMP), or hexamethylphospho as a solvent. Amide (hexamethylphosphoramide, HMPA) may be further included.

For example, when the composition for polyamide interfacial polymerization includes an acyl halide compound, the composition may further include an organic solvent. The organic solvent may be an aliphatic hydrocarbon solvent, for example, a hydrophobic liquid which is not mixed with freons and water such as hexane having 5 to 12 carbon atoms, cyclohexane, heptane, and alkanes, for example, alkanes having 5 to 12 carbon atoms. And mixtures thereof IsoPar (Exxon), ISOL-C (SK Chem), ISOL-G (Exxon) and the like can be used, but is not limited thereto.

Another embodiment of the present disclosure relates to a method of manufacturing a water treatment membrane, comprising: preparing a porous support; And forming a polyamide active layer on the porous support using the polyamide interfacial polymerization composition described above.

According to one embodiment, the composition for polyamide interfacial polymerization comprises an amine compound and a single molecule having a nanoporous structure, and the polyamide active layer by interfacial polymerization by contacting the polyamide interfacial polymerization composition with an acyl halide compound To form. For example, after forming a composition layer comprising an amine compound and a single molecule having a nanoporous structure on the porous support, the acyl halide compound may be contacted on the composition layer to thereby interfacially polymerize the polyamide. The polyamide active layer can be formed. The acyl halide compound may be contacted on the composition layer in a state contained in an organic solvent.

In the above production method, upon contact between the amine compound and the acyl halide compound, the amine compound and the acyl halide compound react to form a polyamide by interfacial polymerization, and are adsorbed onto the microporous support to form a thin film. The contact may be made to the active layer through a method such as dipping, spraying or coating. Interfacial polymerization conditions may be used those known in the art.

The method for forming a composition layer including an amine compound layer or an amine compound and a single molecule having a nanoporous structure on the porous support is not particularly limited. For example, a method of spraying, applying, dipping, dropping, or the like can be used.

The preparation method may additionally perform a step of removing the aqueous solution containing the excess amine compound as needed before contacting the amine compound and the acyl halide compound. When there are too many aqueous solutions containing the amine compound formed on the porous support, the composition in the aqueous solution may be nonuniform, and when the composition in the aqueous solution is nonuniform, a nonuniform active layer may be formed by subsequent interfacial polymerization. Therefore, it is preferable to remove excess aqueous solution after forming an amine aqueous solution layer on the said porous support body. The removal of the excess aqueous solution is not particularly limited, but may be performed using, for example, a sponge, air knife, nitrogen gas blowing, natural drying, a compression roll, or the like.

According to one embodiment of the present specification, as the porous support, a coating layer of a polymer material may be used on a nonwoven fabric. Examples of the polymer material include polysulfone, polyethersulfone, polycarbonate, polyethylene oxide, polyimide, polyetherimide, polyether ether ketone, polypropylene, polymethylpentene, polymethyl chloride and polyvinylidene fluorine. Ride or the like may be used, but is not necessarily limited thereto. Specifically, polysulfone may be used as the polymer material.

According to one embodiment of the present specification, the thickness of the porous support may be 60 μm to 100 μm, but is not limited thereto and may be adjusted as necessary. In addition, the pore size of the porous support is preferably 1 nm to 500 nm, but is not limited thereto.

Another embodiment of the present specification is a porous support; And a polyamide active layer provided on the porous support, and a structure derived from a single molecule having a nanoporous structure is introduced into the polyamide main chain of the polyamide active layer. Here, the structure derived from a single molecule having a nanoporous structure means a structure in which at least two radicals are formed in a polyamide polymerization process in which a single molecule having a nanoporous structure is bonded to the main chain of the polyamide.

According to yet an embodiment of the present disclosure, the polyamide backbone provides a water treatment separation membrane comprising a unit of the formula (3):

[Formula 3]

In Chemical Formula 3, X is a structure derived from a single molecule having a nanoporous structure. The moiety substituted with the amine functional group of the cyclodextrin molecule is reacted with the acyl halide to bind to the polyamide backbone as shown in Formula 3.

According to one example, when a conventional polyamide film is formed using phenylenediamine and trimezoyl chloride, a polyamide structure is formed as shown in the following formula.

However, according to an example of the present invention, a single molecule having a nanoporous structure such as cyclodextrin is introduced into the polyamide main chain as shown in the following structure.

The pores included in the portion indicated by the dotted line may serve as a water molecule transport channel in the polyamide layer as shown in FIG. 2.

The content of a single molecule having a nanoporous structure in the water treatment membrane may be 0.01 wt% to 10 wt%. The content of Chemical Formula 3 in the water treatment membrane may be from 0.01% by weight to 10% by weight.

The water treatment separation membrane may further include an additional layer as necessary, for example, the water treatment separation membrane may further include an antifouling layer provided on the polyamide active layer.

One embodiment of the present invention provides a water treatment module including at least one or more of the aforementioned water treatment separation membrane.

The specific kind of the water treatment module is not particularly limited, and examples thereof include a plate & frame module, a tubular module, a hollow & fiber module or a spiral wound module. In addition, as long as the water treatment module includes the water treatment separation membrane according to the exemplary embodiment of the present specification described above, other configurations and manufacturing methods are not particularly limited, and general means known in the art may be employed without limitation. have.

Meanwhile, the water treatment module according to one embodiment of the present specification has excellent salt removal rate and permeate flow rate, and has excellent chemical stability, and thus may be usefully used for water treatment devices such as household / industrial water purification devices, sewage treatment devices, seawater treatment devices, and the like. have.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the embodiments according to the present disclosure may be modified in various other forms, and the scope of the present specification is not to be interpreted as being limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

Example 1

A polyamide water treatment membrane was prepared using an aqueous solution comprising 3.0 wt% amine compound and 1.0 wt% amine-cyclodextrin and 0.3 wt% acyl halide organic solution on the porous polysulfone support.

Example 2

A polyamide water treatment membrane was prepared using an aqueous solution comprising 3.0 wt% amine compound and 1.5 wt% amine-cyclodextrin and 0.3 wt% acyl halide organic solution on the porous polysulfone support.

[Comparative Example]

On the porous polysulfone support, a polyamide water treatment membrane was prepared by using a 3 wt% amine aqueous solution and a 0.3 wt% acyl halide organic solution.

In order to measure the salt removal rate and the permeate flow rate of the water treatment membranes prepared according to the Examples and Comparative Examples, a water treatment module including a flat plate permeation cell, a high pressure pump, a reservoir and a cooling device was used. The flat permeation cell has a cross-flow structure and an effective permeation area of 29.6 cm ^2. It was.

After mounting the prepared water treatment membrane in the permeation cell, preliminary operation was performed for about 1 hour using tertiary distilled water to stabilize the evaluation equipment. Thereafter, 2000 ppm aqueous sodium chloride solution was used as raw water, and the evaluation was performed at 225 psi operating pressure.

The flux was calculated by measuring the amount of desalted water permeated at 25 ° C for 5 minutes, and the salt removal rate was calculated by analyzing the salt concentrations of raw and produced water using a conductivity meter. .

The performance of the water treatment membranes prepared according to the Examples and Comparative Examples are shown in Table 1 below.

m-phenylenediamine (wt%) Cyclodextrin
(wt%) Salt Removal Rate (%) Permeate Flow Rate (GFD) Comparative Example 1 3.0 - 99.21 16 Example 1 3.0 1.0 99.17 21 Example 2 3.0 1.5 99.15 27

According to Table 1, permeation flux was greatly improved by addition of cyclodextrin.

Claims (13)

Amine compounds; And a gamma-cyclodextrin molecule. delete delete The composition of claim 1, wherein the gamma-cyclodextrin molecule has a structure in which at least one hydroxy functional group is replaced with one or more amine substituents. The composition according to claim 1, wherein the gamma-cyclodextrin molecule comprises a structure of the following Chemical Formula 1 or 2:
[Formula 1]

[Formula 2]

In Chemical Formulas 1 and 2,
Parentheses [] indicate glucose units contained within the cyclodextrin,
m is an integer of 1 or 2 or more,
n is the number of units of glucose of cyclodextrin is 8,
A is an alkylene group having 1 or more carbon atoms,
Dashed line means the connection between glucose units. The composition according to claim 1, wherein the content of the gamma-cyclodextrin molecule is 0.01 to 10% by weight. The composition for polyamide interfacial polymerization according to claim 1, further comprising a solvent. Preparing a porous support; And forming a polyamide active layer on the porous support using the polyamide interfacial polymerization composition according to any one of claims 1 and 4 to 7. The composition according to claim 8, wherein the composition for polyamide interfacial polymerization comprises an amine compound and the gamma-cyclodextrin molecule, and the polyamide active layer is subjected to interfacial polymerization by contacting the polyamide interfacial polymerization composition with an acyl halide compound. Method for producing a water treatment membrane to form. Porous support; And a polyamide active layer provided on the porous support, wherein a structure derived from a gamma-cyclodextrin molecule is introduced into the polyamide main chain of the polyamide active layer. The water treatment separation membrane of claim 10, wherein the polyamide main chain comprises a unit represented by Formula 3 below:
[Formula 3]

In Formula 3, X is a structure derived from a gamma-cyclodextrin molecule. The water treatment separation membrane of claim 10, further comprising an antifouling layer provided on the polyamide active layer. A water treatment module comprising the water treatment separator of any one of claims 10-12.

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