KR102254567B1 - Graphene oxide filler and separating membrane including the same - Google Patents

Abstract

The present invention relates to a polymer composite material separator used in a water treatment process, and in particular, to a polymer composite material separator in which mechanical properties, hydrophilicity, and contamination resistance are improved by adding a modified graphene oxide filler to the polymer separator, and a method of manufacturing the same. About.
In addition, the present invention relates to a graphene oxide filler including an amphoteric material and a method for preparing the same, and provides a graphene oxide filler capable of strong interaction with water and a simple method for modifying graphene oxide in a single process.

Description

Graphene oxide filler and separator containing the same {GRAPHENE OXIDE FILLER AND SEPARATING MEMBRANE INCLUDING THE SAME}

The present invention relates to a separator made of a polymer composite material and a graphene oxide filler added for modification thereof, and particularly to a separator and a graphene oxide filler applicable to an ultrafiltration process in a water treatment process. .

The water treatment process is a water industry that is typically divided into water purification, wastewater treatment and reuse, and seawater desalination. In the conventional water treatment process, methods such as absorption and adsorption have been used to separate contaminants, but these methods occupy a lot of space and have low energy efficiency, and recently, a water treatment process using a polymer membrane that can compensate for this has been in the spotlight.

In the water treatment process using a separation membrane, the membrane fouling phenomenon of the separation membrane is the biggest limitation. Membrane fouling is a phenomenon in which hydrophobic contaminants are deposited on the surface of the separator, which permanently lowers the separation performance such as water permeability and shortens the life of the separator by physicochemical cleaning. In particular, since ultrafiltration membranes separate materials having a higher molecular weight than reverse osmosis, membrane contamination is more severe.

Accordingly, a method of improving the hydrophilicity of the separator has emerged in order to improve the contamination resistance of the separator. Korean Patent Publication No. 2015-0137408 discloses a separation membrane containing metal nanoparticles bound to a hydrophilic compound, and Korean Patent No. 1607752 is a polysulfone separation membrane with hydrophilic hydroxylethyl methacrylate by electron beam irradiation. It discloses a separation membrane in which the hydrophilicity is improved. However, these methods have disadvantages of low dispersibility or unsuitable for mass production.

Further, since a large amount of filler is required to obtain the desired physical properties, agglomeration of the filler easily occurs in the polymer, which negatively affects the mechanical properties of the polymer. Therefore, there is a need to develop a polymer composite material separator that has improved hydrophilicity and contamination resistance as well as mechanical properties.

Korean Patent Publication No. 2015-0137408 (published on December 9, 2015) Korean Patent Registration No. 1607752 (published on December 21, 2015)

The graphene oxide filler of the present invention was devised to solve the above problems, and an object thereof is to provide a graphene oxide filler modified with a surface modifier, which is an amphoteric material, and a method of manufacturing the same.

In addition, another object of the present invention is to provide a polymer composite material separator including the modified graphene oxide filler and a method of manufacturing the same.

The present invention can also aim to achieve these objects and other objects that can be easily derived by a person skilled in the art from the general description of the present specification in addition to the above-described clear objects.

Graphene oxide filler of the present invention in order to achieve the object as described above,

Surface modifiers which are zwitterionic substances; And

It characterized in that it comprises; graphene oxide combined with the surface modifier.

In addition, the surface modifier may be an amino acid.

In addition, the surface modifier may include a thiol group.

In addition, the surface modifier may be cysteine.

And, the weight ratio of the graphene oxide and the surface modifier constituting the graphene oxide bonded to the surface modifier is graphene oxide: surface modifier = 100: 10 to 35, 100: 15 to 30, or 100: 20 to 25 days. have.

In addition, the surface modifier may be bonded to the surface or edge of the graphene oxide.

In addition, the surface modifier may be bonded to graphene oxide with a thioether group.

On the other hand, the method for producing a graphene oxide filler of the present invention,

(A) mixing graphene oxide and a surface modifier that is a zwitterionic material; And

And (B) bonding the surface modifier to the surface or edge of the graphene oxide.

In addition, the surface modifier may be an amino acid.

In addition, the surface modifier may include a thiol group.

In addition, the surface modifier may be cysteine.

And, the step (B) may be a reaction temperature of 55 to 85 ℃, 60 to 80 ℃, or 65 to 75 ℃.

And, the step (B) may be performed in a nitrogen environment.

In addition, the bonding of step (B) may be achieved by a thiol-ene reaction.

On the other hand, the polymer composite material separator of the present invention,

100 parts by weight of a base polymer; And

The graphene oxide filler 0.01 to 5 parts by weight, 0.05 to 4 parts by weight, or 0.08 to 3 parts by weight; may include.

In addition, the base polymer may be selected from the group consisting of a fluorine-based polymer, an olefin-based polymer, a sulfone-based polymer, and a mixture thereof.

In addition, the sulfone-based polymer may be polysulfone or polyethersulfone.

In addition, the polymer composite material separation membrane may be manufactured by a non-solvent induced phase separation process.

In addition, the thickness of the separator may be 30 to 500 µm, 50 to 400 µm, or 70 to 300 µm.

In addition, the polymer composite material separation membrane may be for water treatment, or for ultrafiltration water treatment.

In addition, the hydrophilic index [㎛ ^-1 ] of the polymer composite material separator may be 0.1 to 0.2, 0.12 to 0.18, or 0.14 to 0.16.

The graphene oxide filler according to the present invention has excellent hydrophilicity because it can ionic bond with water including zwitterionic material. In addition, the filler is a nano filler and has excellent dispersibility in the base polymer, so that even a small amount of addition can improve the physical properties of the polymer composite material.

In addition, the method of manufacturing the graphene oxide filler according to the present invention is simple and efficient since the graphene oxide can be modified through a single process.

On the other hand, the polymer composite material separator according to the present invention includes the graphene oxide filler and has excellent hydrophilicity and thus has excellent fouling resistance, so that the membrane has a long life and excellent separation performance. In addition, the stability against external pressure is excellent due to the graphene oxide filler having excellent mechanical properties.

1 schematically shows a method of manufacturing a graphene oxide filler according to an embodiment of the present invention.
Figure 2 schematically shows a method of manufacturing a polymer composite material separator according to an embodiment of the present invention.
3 is a microscope image of a surface (top) and a cross section (bottom) of a polymer composite material separator (right) and a polyether sulfone (left) according to an embodiment of the present invention.
4 is a result of measuring the contact angle of the polymer composite material separator according to an embodiment of the present invention.
5 is a result of measuring the water permeability of the polymer composite material separator according to an embodiment of the present invention.
6 is a result of calculating the normalized flux of the polymer composite material separator according to an embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail.

However, the following is only for describing in detail by exemplifying specific embodiments, and since the present invention may be variously changed and may have various forms, the present invention is not limited to the specific exemplary embodiments illustrated. It is to be understood that the present invention includes all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

In addition, in the following description, there are many specific details such as specific components, etc., which are provided to help a more general understanding of the present invention, and the present invention can be practiced without these specific details. It is self-evident to those who have the knowledge of Further, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In addition, terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

In this application, expressions in the singular include plural expressions unless the context clearly indicates otherwise.

In the present application, terms such as'include','include', or'have' are intended to refer to the presence of features, elements (or constituents), etc. described in the specification, but one or more other features or It does not mean that the component or the like does not exist or cannot be added.

In this application, the hydrophilic index [㎛ ^-1 ] is defined as follows:

Hydrophilic index [㎛ ^-1 ]

= 100

× (Weight of surface modifier / weight of modified graphene oxide filler)

/ Thickness of polymer composite material separator [㎛].

Filtration includes microfiltration, ultrafiltration, and reverse osmosis, depending on the size of the particles to be separated. Microfiltration is a method of separating particles of about 0.1 to 10 µm, ultrafiltration is a method of separating particles of about 1 to 100 nm, and reverse osmosis is a method used for separating molecules or ions of 1 nm or less.

In the water treatment process, a process using a separation membrane is mainly used. In the production of ultrapure water, the reverse osmosis process and the ultra-fine filtration process can be mixed, or the process can be simplified through ultra-fine filtration in a heavy water system that uses wastewater with a low degree of contamination as toilet water.

The separation target for ultrafiltration is mainly high molecular substances such as proteins, enzymes, and polysaccharides. Through the ultrafiltration, the solvent passes through the membrane and the filtered solute is deposited on the membrane, and the solute or contaminant that cannot be permeated forms a layer on the membrane surface, thereby reducing the amount of solvent permeation through the membrane. This is called fouling and is a phenomenon that occurs in most processes using a separation membrane.

The present invention relates to a polymer separator having increased hydrophilicity in order to improve fouling resistance of the separator, wherein the polymer separator is made of a polymer composite material to which the graphene oxide filler of the present invention is added.

The graphene oxide filler of the present invention is characterized in that it comprises a surface modifier that is a zwitterionic material and graphene oxide combined with the surface modifier.

In many cases, a hydrophilic group capable of hydrogen bonding with water was introduced into the membrane as a method to increase the hydrophilicity of the conventional membrane. However, the surface modifier, which is the zwitterionic material of the present invention, is a compound having both an electrically positive charge and a negative charge, and is a material capable of ionic bonding with water. The graphene oxide modified with the surface modifier can have a strong interaction with water through ionic bonds, which are stronger bonds than hydrogen bonds, and a separation membrane including the same may have a significantly increased hydrophilicity than a conventional separation membrane for water treatment.

Therefore, it is preferable that the portion of the surface modifier that binds to graphene oxide is a portion that does not have a charge enough to perform ionic bonding with water or a portion of a functional group having a relatively weak charge. The amphoteric ionic species of the surface modifier may be an amino acid, in which case the carboxyl group (-COO ^-) loss of a proton it is an amino group (-NH ₃ ^+), and protons can be obtained the combination of water and ions.

And, the weight ratio of the graphene oxide and the surface modifier constituting the graphene oxide bonded to the surface modifier is graphene oxide: surface modifier = 100: 10 to 35, 100: 15 to 30, or 100: 20 to 25 days. have. When the weight ratio is within the above range, it is possible to bind a sufficient amount of the surface modifier to the graphene oxide in an economical process.

In the graphene oxide filler, graphene oxide and the surface modifier may be crosslinked through sulfur. The surface modifier may be a zwitterionic material having a functional group including sulfur, and a bond may be formed between sulfur of the surface modifier and a functional group present on the surface or edge of the graphene oxide. The zwitterionic material having a sulfur-containing functional group may be a thiol-containing cysteine.

Functional groups present on the surface or edge of the graphene oxide may include a carboxyl group, a hydroxy group, an epoxy group, a ketone group, an alkenyl group, and the like, and these functional groups may be combined with a surface modifier, but in order to maximize hydrophilicity, the surface modifier is It is preferable to bond with a functional group such as an alkenyl group other than a hydrophilic group.

That is, the graphene oxide filler may be one that forms a bond with sulfur of the surface modifier and carbon present on the surface or edge of the graphene oxide. Specifically, graphene oxide and the surface modifier may be crosslinked through a thioether bond (C-S-C). As an example, the structural formula of the modified graphene oxide filler forming a thioether bond may be as shown in Formula 1 below.

[Formula 1]

On the other hand, the method for producing a graphene oxide filler of the present invention,

(A) mixing graphene oxide and a surface modifier that is a zwitterionic material; And

And (B) bonding the surface modifier to the surface or edge of the graphene oxide.

First, graphene oxide is mixed with a surface modifier, which is a zwitterionic material, and the surface modifier, which is a zwitterionic material, may be an amino acid. In addition, the surface modifier may be a zwitterionic material including a thiol group, and as an example, may be cysteine, an amino acid containing a thiol group. In addition, the graphene oxide may be prepared from graphite through the Hummers' method.

Next, as a step of bonding the surface modifier to the surface or edge of the graphene oxide, a reaction to form a bond between the two materials is induced.

In particular, when the surface modifier is a thiol group or cysteine containing a thiol group, the step (B) is a step of inducing a thiol-ene reaction, wherein the thiol group and the graphene oxide surface or edge It may be a step of forming a bond between the existing carbon-carbon double bonds. This is a radical reaction step, and the reaction may proceed in the presence of an initiator such as AIBN.

The reaction temperature in step (B) may be 55 to 85 °C, 60 to 80 °C, or 65 to 75 °C. When the reaction temperature is less than the above range, it is difficult to sufficiently proceed the reaction. On the other hand, when the reaction temperature exceeds the above range, a problem of thermal decomposition of the reactant may occur or efficiency may decrease.

The thiol-ene reaction can be represented as in Scheme 1 below.

[Scheme 1]

The method for preparing the graphene oxide filler of the present invention can use the thiol-ene reaction, and thus has the advantage of being able to simply modify the graphene oxide in a single process. The graphene oxide filler having a bond formed through the thiol-ene reaction is characterized in that it includes a thioether bond (C-S-C) on the surface or edge of the graphene oxide. 1 is a schematic diagram schematically showing a method of preparing a graphene oxide filler (Cysteine-GO; CysGO) modified by introducing cysteine as an embodiment of the present invention.

On the other hand, the polymer composite material separator of the present invention comprises 100 parts by weight of a base polymer; And 0.01 to 5 parts by weight, 0.05 to 4 parts by weight, or 0.08 to 3 parts by weight of the graphene oxide filler. If the content of the filler is less than the above range, the performance of the filler is not implemented. On the contrary, when the content of the filler exceeds the above range, cracks and defects occur in the separator as the filler aggregates in the polymer, and as a result, the performance of the separator is deteriorated.

Since the separator of the present invention includes a graphene oxide filler, which is a nanomaterial, excellent physical properties can be expected even with a small amount of filler as described above. This is because the nanomaterial has a relatively large contact area with the polymer matrix. Accordingly, it is possible to prevent agglomeration due to the addition of a high content of filler, and the mechanical properties of the separator are improved, so that stability against external pressure is excellent, and deformation or decrease in membrane permeability can be minimized.

The base polymer may be selected from the group consisting of a fluorine-based polymer, an olefin-based polymer, a sulfone-based polymer, and a mixture thereof. Specifically, the base polymer is polysulfone, polysulfone, cellulose acetate, polyamide, polyvinylidene fluoride, polyacrylonitrile. It may be, but is not limited thereto, and may be various polymer materials used for the separation membrane.

On the other hand, the manufacturing method of the polymer composite material separation membrane of the present invention is as follows. After dissolving and dispersing the polymer matrix material and the graphene oxide filler in the same type of solvent, respectively, a polymer mixture solution obtained by mixing each solution is obtained. After that, a non-woven fabric made of polyester, etc., is applied on a plate such as a glass plate, and then the polymer mixture is applied to a certain thickness on the plate, and the polymer mixture is immediately immersed in a non-solvent to prepare a polymer separator, which is dried to obtain a final product. have.

The manufacturing method of the polymer composite material separation membrane is a non-solvent induced phase separation method (NIPS), and the phase separation process is economical because the manufacturing cost is low and the manufacturing process is simple. In addition, the solvent may be NMP (N-Methyl-2-pyrrolidone), DMAc (Dimethylacetamide), or DMF (Dimethylformamide), and the non-solvent may be distilled water, but is not limited thereto. Non-selling can be adopted.

Figure 2 is an embodiment of the manufacturing method of the polymer composite material separator, schematically showing the overall process of manufacturing a polyethersulfone separator (CysGO/PESf) to which the modified graphene oxide filler (CysGO) is added by introducing the cysteine. It is shown as.

A separator manufactured by a non-solvent-induced phase separation process generally has a relatively low tensile strength, so when the film shrinks under a certain pressure, a phenomenon in which the membrane permeability decreases may occur. However, the polymer composite material separator of the present invention can minimize the membrane shrinkage phenomenon of the membrane by adding a modified filler based on graphene oxide having excellent mechanical properties, thereby reducing the reduction rate of water permeability due to membrane shrinkage. I can.

In addition, the polymer composite material separator may have a thickness of 30 to 500 µm, 50 to 400 µm, or 70 to 300 µm. If the thickness of the separator is less than the above range, the mechanical strength is weak and deformation easily occurs during the water treatment process, whereas if the thickness of the separator exceeds the above range, the path through which water passes is lengthened, resulting in a decrease in the performance of the separator as the water permeability decreases. .

In addition, the hydrophilic index [㎛ ^-1 ] of the polymer composite material separator may be 0.1 to 0.2, 0.12 to 0.18, or 0.14 to 0.16. In the present invention, the hydrophilic index [㎛ ^-1 ] is defined as follows:

Hydrophilic index [㎛ ^-1 ]

= 100

× (Weight of surface modifier / weight of modified graphene oxide filler)

/ Thickness of polymer composite material separator [㎛].

In the present invention, when the hydrophilicity index is within the above range, it is possible to express a sufficient degree of hydrophilicity at an appropriate level of the thickness of the separator.

Figure 3 is a surface (top) and cross-section (bottom) microscopic images of a pure polyethersulfone (Neat PESf) separator and a polymer composite separator (0.5 CysGO/PESf) added with a graphene oxide filler according to the present invention at 100,000 magnification to be. From FIG. 3, it can be seen that even though the filler (CysGO) of the present invention is mixed, not only the typical pore structure of the polymer membrane is maintained, but also the size and number of pores increase according to the mixing of the hydrophilic filler.

The polymer composite material separation membrane of the present invention has excellent hydrophilicity and, when used as a separation membrane for an ultrafiltration process that mainly separates proteins, has excellent separation performance and contamination resistance, can extend the life of the separation membrane, and increase the efficiency of the water treatment process. I can. In addition, the separation membrane according to the present invention may be used as a support layer for physical support of a reverse osmosis membrane used for seawater desalination as well as an ultrafiltration membrane for water treatment, and furthermore, it may be applied in all fields of a separation process using a separation membrane.

Hereinafter, an embodiment of the present invention will be described.

Example

practice Yes 1: Preparation of graphene oxide filler CysGO

Graphene oxide (GO) was prepared from graphite through the Hummers' method. Thereafter, cysteine was mixed with graphene oxide in a solvent DMF, and a _{thiol-ene reaction was induced in the presence of initiators AIBN and N 2,} and the reaction temperature was set to 70°C. Through the above reaction, graphene oxide was modified, and a graphene oxide filler (CysGO) into which cysteine was introduced was obtained. The weight ratio of graphene oxide and cysteine constituting the graphene oxide filler into which the cysteine was introduced was tested by thermogravimetric analysis, and as a result, graphene oxide: cysteine = 100: 23 was found.

Example 2: Preparation of 0.1 CysGO/PESf polymer composite material separator

After dissolving and dispersing 0.02 g of CysGO and 20 g of polyethersulfone (PESf) obtained in Example 1 in a solvent DMAc (dimethylacetamide), each solution was mixed to form 100 g of a polymer solution. Thereafter, the polymer solution was applied to a thickness of 200 µm on a glass plate wrapped with a polyester nonwoven fabric, and immediately immersed in distilled water to prepare a 0.1 CysGO/PESf polymer composite material separator.

Example 3: Preparation of 0.5 CysGO/PESf polymer composite material separator

It was prepared in the same manner as in Example 2, but the CysGO was 0.1 g to prepare a 0.5 CysGO/PESf polymer composite separator.

Example 4: Preparation of 1.0 CysGO/PESf polymer composite material separator

It was prepared in the same manner as in Example 2, but the CysGO was 0.2 g to prepare a 1.0 CysGO/PESf polymer composite separator.

Example 5: Preparation of 2.0 CysGO/PESf polymer composite material separator

It was prepared in the same manner as in Example 2, but the CysGO was 0.4 g to prepare a 2.0 CysGO/PESf polymer composite material separator.

As a control example, polyethersulfone (Neat PESf) without adding a filler and the compositions of Examples 2 to 5 are shown in Table 1 below.

Sample name PESf CysGO DMAc Contrast Neat PESf 20 0 80 Example 2 0.1 CysGO/PESf 20 0.02 79.98 Example 3 0.5 CysGO/PESf 20 0.1 79.9 Example 4 1.0 CysGO/PESf 20 0.2 79.8 Example 5 2.0 CysGO/PESf 20 0.4 79.6

Test Example 1: Evaluation of hydrophilicity of a polymer composite material separator

In order to evaluate the hydrophilicity of the control examples and examples 2 to 5, the contact angle was measured. Water droplets were dropped on the surface of the separator according to the Comparative Examples and Examples 2 to 5 to measure the angle formed by the separator surface and the water droplets, and the results are shown in Tables 2 and 3 below.

Contact angle (°) Contrast 73.2 ± 2.1 Example 2 66.5 ± 1.1 Example 3 53.2 ± 1.6 Example 4 51.7 ± 2.4 Example 5 50.5 ± 1.9

Compared to the control example, the contact angle of the separator to which the filler of the present invention was added was smaller, and it was confirmed that the hydrophilicity of the separator was improved through this. As the content of the filler increased, the hydrophilicity increased, but the rate of increase decreased.

Test Example 2: Evaluation of water permeability of a polymer composite material separator

The water permeability was evaluated using a total filter device for the control examples and examples 2 to 5 above. Proteins, which are the main separation targets of the membrane for the ultrafiltration process, were selected as contaminants, and an aqueous bovine serum albumin solution (BSA solution) and distilled water were used as influent. The results of measuring the water permeability for Control Examples and Examples 2 to 5 are shown in Table 3 and FIG. 4 below.

Transmittance (LMH) Distilled water BSA solution Contrast 51.7 22.0 Example 2 65.1 34.3 Example 3 82.6 56.8 Example 4 90.9 65.8 Example 5 102.4 61.0

In distilled water, the transmittance of all examples was increased compared to the control example, and Example 5 showed the highest transmittance. This is a phenomenon that occurs as the hydrophilic filler is mixed.

The bovine serum albumin aqueous solution also increased the permeability of all examples compared to the control example, and Example 5 showed the highest permeability. This is a phenomenon that occurs as the hydrophilic filler is mixed. In addition, as compared to the permeability in distilled water, the permeability of the separator to which the filler was added showed a small decrease in the permeability, indicating that the improvement in hydrophilicity by the filler increased the fouling resistance of the separator.

Test Example 3: Evaluation of separation performance and antifouling properties of a polymer composite material separator

In order to evaluate the separation performance and antifouling properties for the Comparative Examples and Examples 2 to 5, distilled water and an aqueous protein solution were alternately used as influent water in a total filtration device, and permeability was measured. In particular, normalized flux was calculated and shown in FIG. 6 to confirm the decrease in transmittance and recovery of the transmittance.

6, it was confirmed that the composite material separator mixed with the filler exhibited excellent recovery of water permeability even after the application of the aqueous protein solution. This is a phenomenon that appears due to the improvement of fouling resistance as the hydrophilicity of the separator is improved.

In addition, the reduction in water permeability due to the membrane compression at the beginning of the measurement according to the pressing conditions was also found to be less in the composite material separation membrane. This is due to the addition of a graphene oxide-based filler having excellent mechanical properties, and by using a nanomaterial as a filler, it can be seen that the physical properties of the composite material were improved with a very small amount of filler.

In the above, preferred embodiments of the present invention have been described, but the present invention is not limited to the specific embodiments described above, and those of ordinary skill in the art can implement various modifications without departing from the gist of the present invention. Of course it is possible. Therefore, the scope of the present invention should not be construed as limited to the above embodiments, and should be determined by the claims and equivalents to the claims to be described later.

Cys-GO: Cysteine modified graphene oxide
PESf: polysulfone

Claims (7)

delete delete delete delete As a method of manufacturing a polymer composite material separator,
(A) 100 parts by weight of graphene oxide and 20 to 25 parts by weight of cysteine were mixed in a solvent DMF, and a thiol-ene reaction was induced at 65 to 75° C. in the presence of _{initiators AIBN and N 2} Obtaining a graphene oxide modified with cysteine,
(B) 100 parts by weight of a base polymer selected from the group consisting of fluorine-based polymers, olefin-based polymers, sulfone-based polymers, and mixtures thereof, and 0.08 to 3 parts by weight of graphene oxide modified with the cysteine, respectively NMP (N-Methyl-2- pyrrolidone), DMAc (Dimethylacetamide), or after dissolving and dispersing in DMF (Dimethylformamide), obtaining a polymer mixture in which each solution is mixed, and
(C) After spreading a nonwoven fabric on a glass plate, applying the polymer mixture thereon, immediately immersing it in water, and drying it to prepare a polymer separator.
Including,
Hydrophilic index [㎛ ^-1 ]
= 100
× (Weight of surface modifier / weight of modified graphene oxide filler)
/ Thickness of polymer composite material separator [㎛]
The hydrophilic index of the polymer composite material separation membrane defined as [㎛ ^-1 ] is 0.14 to 0.16,
Method for producing a polymer composite material separator.
delete delete

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