CN111437734A - Superhydrophobic solvent-resistant composite nanofiltration membrane and preparation method thereof - Google Patents

Abstract

The invention discloses a super-hydrophobic solvent-resistant composite nanofiltration membrane and a preparation method thereof. The method for preparing the super-hydrophobic solvent-resistant composite nanofiltration membrane comprises the following steps: (1) providing a base film; (2) forming an aqueous coating on at least a portion of a surface of the base film using an aqueous solution comprising: piperazine, proton absorbent, surfactant and water; (3) forming an oil phase coating on at least part of the surface of the water phase coating far away from the base film by using the oil phase solution, and carrying out interfacial polymerization reaction on the oil phase coating and the water phase coating to form a composite layer; the oil phase solution comprises trimesoyl chloride, a hydrophobic end-capping reagent and n-hexane; (4) and (4) carrying out heat treatment on the product obtained in the step (3) to obtain the super-hydrophobic solvent-resistant composite nanofiltration membrane. The method has the advantages of simple process and mild conditions, and the prepared nanofiltration membrane has strong super-hydrophobicity and solvent resistance and has good application prospect in the field of organic solvent system separation.

Description

Superhydrophobic solvent-resistant composite nanofiltration membrane and preparation method thereof

technical field

The present invention relates to the technical field of membrane separation, in particular, the present invention relates to a method for preparing a super-hydrophobic solvent-resistant composite nanofiltration membrane and a super-hydrophobic solvent-resistant composite nanofiltration membrane prepared by the method.

Background technique

Nanofiltration membrane separation is a new membrane separation technology between ultrafiltration membrane separation and reverse osmosis membrane separation. It is widely used in hard water softening, removal of a small amount of organic matter in water, dye purification and desalination, separation and purification of organic matter of different molecular weights many industrial fields. Most of the current nanofiltration membranes are water-based, mainly for systems using water as a solvent, but in practical industrial applications, there are a large number of non-aqueous systems for material separation, which requires nanofiltration membranes with good solvent resistance.

Patent CN106902651A reports a composite membrane with gradient change in hydrophilicity and hydrophobicity and its preparation method. On the organic or inorganic base membrane, the silica sol and the titanium dioxide sol are repeatedly positioned and infiltrated along a specific direction, and the base is changed by adjusting the inorganic nanoparticles. The surface roughness of the membrane was obtained to obtain a composite membrane with gradient changes in hydrophilicity and hydrophobicity.

In patent CN102953105A, electrochemical deposition technology is used to deposit long-chain alkyl siloxane hydrolyzate on the solid surface to realize the super-hydrophobicity of the nanofiltration membrane.

Patent CN103993423A adopts electrospinning technology, mixes SiO2 nanoparticles modified by epoxy modified silicone oil with polystyrene solution and polyacrylonitrile solution to obtain two spinning solutions, and carries out double-nozzle electrospinning and drying to obtain super-hydrophobic fibers membrane.

At present, the general method for improving the hydrophobicity and solvent resistance of nanofiltration membranes is to add some hydrophobic inorganic nanoparticles. However, the existing methods for improving the hydrophobicity and solvent resistance of filter membranes still need to be improved.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, an object of the present invention is to propose a method for preparing a superhydrophobic solvent-resistant composite nanofiltration membrane and a superhydrophobic solvent-resistant composite nanofiltration membrane prepared by the method. The method has simple process and mild conditions, and the prepared nanofiltration membrane has strong superhydrophobicity and solvent resistance, and has a good application prospect in the field of organic solvent system separation.

In one aspect of the present invention, the present invention provides a method for preparing a superhydrophobic solvent-resistant composite nanofiltration membrane. According to an embodiment of the present invention, the method includes: (1) providing a base film; (2) using an aqueous phase solution to form an aqueous phase coating on at least part of the surface of the base film, the aqueous phase solution comprising: piperazine , a proton absorber, a surfactant and water; (3) using an oil phase solution to form an oil phase coating on at least part of the surface of the water phase coating away from the base film, and make the oil phase coating and all the The water-phase coating undergoes an interfacial polymerization reaction to form a composite layer; the oil-phase solution includes trimesoyl chloride, a hydrophobic end-capping agent and n-hexane; (4) heat-treating the product obtained in step (3) to obtain the ultra-high temperature Hydrophobic solvent-resistant composite nanofiltration membrane.

According to the method for preparing the super-hydrophobic solvent-resistant composite nanofiltration membrane according to the embodiment of the present invention, the water-phase coating and the oil-phase coating are formed on the surface of the base membrane in turn, and the interfacial polymerization reaction of the oil-phase coating and the water-phase coating occurs, Get a high-performance composite functional layer. In this method, by mixing a hydrophobic end-capping agent into the oil phase solution and changing the structure of the polymer in the composite functional layer through interfacial polymerization, the prepared superhydrophobic solvent-resistant composite nanofiltration membrane has more stable performance. And by controlling the amount of the hydrophobic end-capping agent, the hydrophobicity of the nanofiltration membrane can be adjusted within a certain range to meet its application needs in different occasions. At the same time, the method has simple process and mild conditions, and the prepared nanofiltration membrane has strong superhydrophobicity and solvent resistance, and has a good application prospect in the field of organic solvent system separation.

In addition, the method for preparing the super-hydrophobic solvent-resistant composite nanofiltration membrane according to the above-mentioned embodiment of the present invention may also have the following additional technical features:

In some embodiments of the present invention, the base membrane is a polysulfone ultrafiltration membrane.

In some embodiments of the present invention, the proton absorber is selected from at least one of sodium carbonate, sodium bicarbonate, sodium phosphate, sodium hydrogen phosphate, sodium hydroxide, potassium hydroxide, and triethylamine.

In some embodiments of the present invention, the surfactant is selected from at least one of sodium dodecyl sulfate, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate.

In some embodiments of the present invention, the aqueous phase solution includes 0.1-5 wt % piperazine, 0.1-1 wt % proton absorber, 0.05-0.3 wt % surfactant and the balance water. Preferably, the aqueous phase solution comprises 1-3 wt % of piperazine, 0.3-0.5 wt % of proton absorber, 0.1-0.15 wt % of surfactant and the balance of water.

In some embodiments of the present invention, the hydrophobic end-capping agent is selected from at least one of naphthoyl chloride, naphthalenesulfonyl chloride, anthracenecarbonyl chloride, and anthracenesulfonyl chloride.

In some embodiments of the present invention, in the oil phase solution, the content of the trimesic acid chloride is 0.05-0.5 wt %, and the dosage ratio of the hydrophobic end-capping agent to the trimesic acid chloride is (1 :9)～(4:1). Preferably, in the oil phase solution, the content of the trimesoyl chloride is 0.1-0.2 wt %, and the dosage ratio of the hydrophobic end-capping agent to the trimesoyl chloride is 1:1.

In some embodiments of the present invention, the first coating layer and the second coating layer are formed by dip coating.

In some embodiments of the present invention, the heat treatment is performed at 40˜80° C. for 30 s˜5 min.

In some embodiments of the present invention, the superhydrophobic solvent-resistant composite nanofiltration membrane product prepared by the above method is stored in deionized water.

In another aspect of the present invention, the present invention provides a superhydrophobic solvent-resistant composite nanofiltration membrane. According to the embodiment of the present invention, the super-hydrophobic solvent-resistant composite nanofiltration membrane is prepared by the method for preparing a super-hydrophobic solvent-resistant composite nanofiltration membrane in the above embodiment. Therefore, the nanofiltration membrane has strong superhydrophobicity and solvent resistance, has a good application prospect in the field of organic solvent system separation, and has the advantages of simple preparation method and mild conditions.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic flowchart of a method for preparing a superhydrophobic solvent-resistant composite nanofiltration membrane according to an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below. The embodiments described below are exemplary, only for explaining the present invention, and should not be construed as limiting the present invention. If no specific technique or condition is indicated in the examples, the technique or condition described in the literature in the field or the product specification is used. The reagents or instruments used without the manufacturer's indication are conventional products that can be obtained from the market.

In one aspect of the present invention, the present invention provides a method for preparing a superhydrophobic solvent-resistant composite nanofiltration membrane. According to an embodiment of the present invention, the method includes: (1) providing a base film; (2) forming an aqueous coating on at least part of the surface of the base film with an aqueous solution, the aqueous solution comprising: piperazine, a proton absorber , surfactant and water; (3) use the oil phase solution to form an oil phase coating on at least part of the surface of the water phase coating away from the base film, and cause the oil phase coating and the water phase coating to undergo interfacial polymerization to form a composite layer; the oil phase solution includes trimesoyl chloride, hydrophobic end-capping agent and n-hexane; (4) heat-treating the product obtained in step (3) to obtain a super-hydrophobic solvent-resistant composite nanofiltration membrane.

According to the method for preparing the super-hydrophobic solvent-resistant composite nanofiltration membrane according to the embodiment of the present invention, the water-phase coating and the oil-phase coating are formed on the surface of the base membrane in turn, and the interfacial polymerization reaction of the oil-phase coating and the water-phase coating occurs, Get a high-performance composite functional layer. In this method, by mixing a hydrophobic end-capping agent into the oil phase solution and changing the structure of the polymer in the composite functional layer through interfacial polymerization, the prepared superhydrophobic solvent-resistant composite nanofiltration membrane has more stable performance. And by controlling the amount of the hydrophobic end-capping agent, the hydrophobicity of the nanofiltration membrane can be adjusted within a certain range to meet its application needs in different occasions. At the same time, the method has simple process and mild conditions, and the prepared nanofiltration membrane has strong superhydrophobicity and solvent resistance, and has a good application prospect in the field of organic solvent system separation.

The method for preparing the superhydrophobic solvent-resistant composite nanofiltration membrane according to the embodiment of the present invention is further described in detail below. 1, according to an embodiment of the present invention, the method includes:

S100: Provide base film

The specific types of the above-mentioned base films are not particularly limited, and those skilled in the art can select common base films in the field according to actual needs. According to some embodiments of the present invention, the above-mentioned base membrane is a polysulfone ultrafiltration membrane. Therefore, the prepared superhydrophobic solvent-resistant composite nanofiltration membrane product has better performance.

S200: Forming an aqueous coating

In this step, an aqueous phase coating is formed on at least part of the surface of the base film using an aqueous phase solution, the aqueous phase solution comprising: piperazine (anhydrous piperazine), proton absorber, surfactant and water. According to some embodiments of the present invention, the oil phase coating may be formed by dip coating the base film with an oil phase solution.

The main function of the proton absorber is to absorb the acid (such as hydrochloric acid) generated in the interfacial polymerization reaction between the water phase coating and the oil phase coating, so as to promote the forward progress of the interfacial polymerization reaction. According to some embodiments of the present invention, the above proton absorbent may be selected from at least one of sodium carbonate, sodium bicarbonate, sodium phosphate, sodium hydrogen phosphate, sodium hydroxide, potassium hydroxide, and triethylamine. By using the above-mentioned proton absorbent, the forward progress of the interfacial polymerization reaction can be further facilitated.

The main function of the surfactant is to promote the diffusion of the water phase to the oil phase, thereby increasing the rate of interfacial polymerization. According to some embodiments of the present invention, the above-mentioned surfactant may be selected from at least one of sodium dodecyl sulfate, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate. By using the above-mentioned surfactant, the rate of the polymerization reaction can be further increased.

According to some embodiments of the present invention, the above-mentioned aqueous phase solution includes 0.1-5 wt % piperazine, 0.1-1 wt % proton absorber, 0.05-0.3 wt % surfactant and the balance of water. Specifically, the content of piperazine (piperazine anhydrous) can be 0.1wt%, 0.5wt%, 0.8wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 4wt%, 4.5wt% , 5wt%, etc.; the content of proton absorber can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.8wt%, 1wt%, etc.; the content of surfactant can be 0.05wt% , 0.08wt%, 0.1wt%, 0.12wt%, 0.15wt%, 0.2wt%, 0.25wt%, 0.3wt%, etc. Preferably, the above-mentioned aqueous phase solution includes 1-3 wt % of piperazine, 0.3-0.5 wt % of proton absorber, 0.1-0.15 wt % of surfactant and the balance of water. The inventor found in the research that if the amount of anhydrous piperazine is less than 0.1 wt%, the monomer concentration of the aqueous phase is too low, and it is difficult to form a complete functional layer; If the concentration of the water phase is too large, it is not easy to polymerize to form long-chain macromolecules, and the formed functional layer is relatively loose, and the retention rate will be lower. If the amount of proton absorbent is less than 0.1wt%, it is not easy to absorb protons, the normal progress of the polymerization reaction cannot be fully guaranteed, and it is difficult to form a dense functional layer; if the amount of proton absorbent is higher than 0.5wt%, the alkali If the property is too large, the formed polyamide functional layer is easily hydrolyzed. If the amount of surfactant is less than 0.05wt%, the effect of increasing the reaction speed will not be achieved; if the amount of surfactant is higher than 0.3wt%, it will easily emulsify the water phase monomer molecules and affect the polymerization reaction.

S300: Forms an oily coating and undergoes interfacial polymerization

In this step, the oil-phase coating is formed on at least part of the surface of the water-phase coating away from the base film by using the oil-phase solution, and the interfacial polymerization reaction of the oil-phase coating and the water-phase coating occurs to form a composite layer; the oil-phase solution includes trimesoyl chloride, hydrophobic capping agent and n-hexane. According to some embodiments of the present invention, the oil phase coating may be formed by dip coating the S200 resulting product with the oil phase solution.

According to some embodiments of the present invention, the hydrophobic end-capping agent may be selected from at least one of naphthoyl chloride, naphthalenesulfonyl chloride, anthracenecarbonyl chloride, and anthracenesulfonyl chloride. These hydrophobic end-capping agents have strong hydrophobicity with multiple benzene rings and contain monofunctional acid chlorides. Thus, the hydrophobicity and solvent resistance of the superhydrophobic solvent-resistant composite nanofiltration membrane can be further improved.

According to some embodiments of the present invention, in the above-mentioned oil phase solution, the content of trimesoyl chloride may be 0.05 to 0.5 wt %, and the dosage ratio of the hydrophobic end-capping agent to trimesic acid chloride may be (1:9) to ( 4:1). Yes, the content of trimesoyl chloride can be 0.05wt%, 0.08wt%, 0.1wt%, 0.15wt%, 0.2wt%, 0.25wt%, 0.3wt%, 0.5wt% and the like. The dosage ratio of the hydrophobic end-capping agent to trimesoyl chloride can be 1:9, 1:6, 1:2, 1:1, 2:1, 4:1 and the like. Preferably, in the above oil phase solution, the content of trimesoyl chloride is 0.1-0.2 wt %, and the dosage ratio of the hydrophobic end-capping agent to the trimesoyl chloride is 1:1. The inventors found in the research that if the amount of trimesoyl chloride is less than 0.05wt%, the reaction is insufficient and a complete functional layer cannot be formed; if it is higher than 0.5wt%, the resulting membrane is too dense and the flux decreases seriously. If the dosage ratio of hydrophobic end capping agent to trimesoyl chloride is too low, the effect of hydrophobic end capping will not be achieved; The layers are not dense and cannot even form functional layers.

S400: Heat Treatment

In this step, heat treatment is performed on the product obtained by S300 to obtain a super-hydrophobic solvent-resistant composite nanofiltration membrane.

According to some embodiments of the present invention, the heat treatment is performed at 40˜80° C. for 30 s˜5 min. Specifically, the heat treatment temperature can be 40°C, 50°C, 60°C, 70°C, 80°C, etc., and the heat treatment time can be 30s, 1min, 2min, 3min, 4min, 5min, etc. The inventor found in the research that if the heat treatment time is too short or the heat treatment temperature is too low, the heat treatment effect will be insignificant, the degree of polymerization reaction will be insufficient, and the product retention will be low; while the heat treatment time is too long or the heat treatment temperature is too high, the base film will be Shrinkage cavities, product throughput decreased.

In another aspect of the present invention, the present invention provides a superhydrophobic solvent-resistant composite nanofiltration membrane. According to the embodiment of the present invention, the super-hydrophobic solvent-resistant composite nanofiltration membrane is prepared by the method for preparing the super-hydrophobic solvent-resistant composite nanofiltration membrane in the above embodiment. Therefore, the nanofiltration membrane has strong superhydrophobicity and solvent resistance, has a good application prospect in the field of organic solvent system separation, and has the advantages of simple preparation method and mild conditions.

In addition, it should be noted that all the features and advantages described above for the method for preparing the superhydrophobic solvent-resistant composite nanofiltration membrane are also applicable to the superhydrophobic solvent-resistant composite nanofiltration membrane. I won't go into details here.

The present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

Example 1

2 wt % of anhydrous piperazine, 0.1 wt % of sodium hydroxide and 0.1 wt % of sodium dodecyl sulfonate are dissolved in water to prepare an aqueous solution. 0.1 wt % of trimesoyl chloride and 0.1 wt % of hydrophobic end capping agent 2-naphthalenesulfonyl chloride are dissolved in n-hexane to prepare an oil phase solution. Immerse the cleaned polysulfone ultrafiltration base membrane in the water phase solution for 40s, take it out, and dry the excess water on the surface with an air knife, then immerse it in the oil phase solution for 1min, take it out and place it in an oven at 60°C After drying for 2 min, the finished nanofiltration membrane was finally obtained, which was placed in deionized water for testing.

Example 2

3 wt % of anhydrous piperazine, 0.1 wt % of sodium carbonate and 0.1 wt % of sodium dodecyl sulfonate are dissolved in water to prepare an aqueous solution. 0.2wt% trimesoyl chloride and 0.05wt% hydrophobic end capping agent 2-naphthalenesulfonyl chloride are dissolved in n-hexane to prepare an oil phase solution. Immerse the cleaned polysulfone ultrafiltration base membrane in the aqueous phase solution for 40s, take it out, and dry the excess water on the surface with an air knife, then immerse it in the oil phase solution for 1min, take it out and place it in an oven at 80°C After drying for 1 min, the finished nanofiltration membrane was finally obtained, which was placed in deionized water for testing.

Example 3

2 wt % of anhydrous piperazine, 0.1 wt % of potassium hydroxide and 0.1 wt % of sodium dodecyl sulfonate are dissolved in water to prepare an aqueous solution. 0.15wt% trimesoyl chloride and 0.05wt% hydrophobic end capping agent 1-anthracenecarbonyl chloride are dissolved in n-hexane to prepare an oil phase solution. Immerse the cleaned polysulfone ultrafiltration base membrane in the water phase solution for 40s, take it out, and dry the excess water on the surface with an air knife, then immerse it in the oil phase solution for 1min, take it out and place it in an oven at 60°C After drying for 1 min, the finished nanofiltration membrane was finally obtained, which was placed in deionized water for testing.

Example 4

2 wt % of anhydrous piperazine, 0.1 wt % of sodium hydroxide and 0.1 wt % of sodium dodecyl sulfonate are dissolved in water to prepare an aqueous solution. 0.2wt% trimesoyl chloride and 0.1wt% hydrophobic end capping agent 1-naphthoyl chloride were dissolved in n-hexane to prepare an oil phase solution. Immerse the cleaned polysulfone ultrafiltration base membrane in the aqueous phase solution for 40s, take it out, and dry the excess water on the surface with an air knife, then immerse it in the oil phase solution for 1min, take it out and place it in an oven at 80°C After drying for 1 min, the finished nanofiltration membrane was finally obtained, which was placed in deionized water for testing.

Comparative ratio

2 wt % of anhydrous piperazine, 0.1 wt % of sodium hydroxide and 0.1 wt % of sodium dodecyl sulfonate are dissolved in water to prepare an aqueous solution. Dissolve 0.2wt% trimesoyl chloride in n-hexane to prepare an oil phase solution. Immerse the cleaned polysulfone ultrafiltration base membrane in the water phase solution for 40s, take it out, and dry the excess water on the surface with an air knife, then immerse it in the oil phase solution for 1min, take it out and place it in an oven at 60°C After drying for 2 min, the finished nanofiltration membrane was finally obtained, which was placed in deionized water for testing.

test case

The separation performance and solvent resistance performance of the nanofiltration membranes prepared in Examples 1 to 4 and Comparative Examples were compared. Test conditions: The rejection rate and corresponding solvent flux of the prepared nanofiltration membrane were measured with 100 mg·L ^-1 Rhodamine B (479 Da)-ethanol solution at 25°C and 1.0 MPa. The results are shown in Table 1.

Table 1 Comparative Example and Example Nanofiltration Membrane Separation Performance Comparison

Retention rate (%) Water Flux (LMH) Example 1 97.43 81.4 Example 2 98.57 75.2 Example 3 97.75 77.2 Example 4 98.29 71.9 Comparative ratio 75.22 123.4

The test results show that the nanofiltration membrane prepared in the comparative example is easy to swell in ethanol, resulting in a decrease in the rejection rate and an increase in the water flux. On the other hand, the nanofiltration membranes prepared in Examples 1 to 4 have relatively good and stable separation performance and water flux performance in ethanol through hydrophobic end capping, indicating that they have better solvent resistance performance.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (10)

1. A method for preparing a super-hydrophobic solvent-resistant composite nanofiltration membrane is characterized by comprising the following steps:

(1) providing a base film;

(2) forming an aqueous coating on at least a portion of a surface of the base film using an aqueous solution comprising: piperazine, proton absorbent, surfactant and water;

(3) forming an oil phase coating on at least part of the surface of the water phase coating far away from the base film by using an oil phase solution, and carrying out interfacial polymerization reaction on the oil phase coating and the water phase coating to form a composite layer; the oil phase solution comprises trimesoyl chloride, a hydrophobic end-capping agent and n-hexane;

(4) and (4) carrying out heat treatment on the product obtained in the step (3) to obtain the super-hydrophobic solvent-resistant composite nanofiltration membrane.

2. The method of claim 1, wherein the base membrane is a polysulfone ultrafiltration membrane.

3. The method according to claim 1, wherein the proton absorbent is selected from at least one of sodium carbonate, sodium bicarbonate, sodium phosphate, sodium hydrogen phosphate, sodium hydroxide, potassium hydroxide, and triethylamine.

4. The method of claim 1, wherein the surfactant is selected from at least one of sodium dodecyl sulfate, and sodium dodecyl benzene sulfonate.

5. The method according to claim 1, wherein the aqueous solution comprises 0.1 to 5 wt% of piperazine, 0.1 to 1 wt% of a proton absorbent, 0.05 to 0.3 wt% of a surfactant, and the balance of water.

6. The method of claim 1, wherein the hydrophobic capping agent is selected from at least one of naphthoyl chloride, anthracoyl chloride, anthracenesulfonyl chloride.

7. The method according to claim 1, wherein the content of the trimesoyl chloride in the oil phase solution is 0.05-0.5 wt%, and the usage ratio of the hydrophobic end-capping agent to the trimesoyl chloride is (1:9) - (4: 1).

8. The method of claim 1, wherein the first coating and the second coating are formed by dip coating.

9. The method according to claim 1, wherein the heat treatment is performed at 40 to 80 ℃ for 30s to 5 min.

10. A super-hydrophobic solvent-resistant composite nanofiltration membrane, which is prepared by the method for preparing the super-hydrophobic solvent-resistant composite nanofiltration membrane according to any one of claims 1 to 9.

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