阅读说明：本技术 一种聚酰亚胺P84/MIL-101（Cr）混合基质膜的制备方法 (Preparation method of polyimide P84/MIL-101(Cr) mixed matrix film ) 是由 盖方圆 梁超安 赵晓刚 刘振国 王严 张铁欣 于 2021-09-13 设计创作，主要内容包括：本发明涉及一种基于MIL-101(Cr)混合基质膜的制备方法。本发明属于水处理膜分离领域,具体涉及聚酰亚胺P84和MIL-101(Cr)的混合基质膜,其制备方法包括制备MIL-101(Cr)：将九水硝酸铬与对苯二甲酸溶于去离子水中,水热条件下得到MIL-101(Cr)材料。将聚酰亚胺P84和不同比例的MIL-101(Cr)溶于N,N-二甲基甲酰胺中,超声,搅拌,相转化固化成膜。本方法制备出的P84/MIL-101(Cr)膜,在室温下具有优异的甲基橙和亚甲基蓝混合染料去除能力,具有制备方法简单、成本低廉,易于实现工业化生产的特点。(The invention relates to a preparation method of a mixed matrix film based on MIL-101 (Cr). The invention belongs to the field of water treatment membrane separation, and particularly relates to a mixed matrix membrane of polyimide P84 and MIL-101(Cr), wherein the preparation method comprises the following steps: dissolving chromium nitrate nonahydrate and terephthalic acid in deionized water, and obtaining the MIL-101(Cr) material under the hydrothermal condition. Dissolving polyimide P84 and MIL-101(Cr) with different proportions in N, N-dimethylformamide, performing ultrasonic treatment, stirring, and performing phase inversion curing to form a film. The P84/MIL-101(Cr) film prepared by the method has excellent removal capability of methyl orange and methylene blue mixed dye at room temperature, and has the characteristics of simple preparation method, low cost and easy realization of industrial production.)

1. A preparation method of a P84/MIL-101(Cr) mixed matrix film is characterized by comprising the following specific steps:

(1) 4.000 g of chromium nitrate nonahydrate, 1.660 g of terephthalic acid and 48 ml of water are stirred at room temperature for 30 minutes, and hydrothermal reaction is carried out at 220 ℃ for 8 hours to prepare MIL-101 (Cr);

(2) putting MIL-101(Cr) with the solid content of 0-20% into a three-neck flask, adding a certain amount of solvent N, N-dimethylformamide, carrying out ultrasonic treatment for 60 minutes, adding 6 grams of polymer P84 granules, stirring for 10 hours at room temperature, standing overnight, and defoaming to prepare 18% P84/MIL-101 casting solution;

(3) and pouring the casting solution on a clean glass plate, scraping the film by using a 200-micron scraper, immediately transferring the film into deionized water, and performing phase inversion to obtain a P84/MIL-101 mixed matrix film.

2. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: 4.000 g of chromium nitrate nonahydrate, 1.660 g of terephthalic acid and 48 ml of water were stirred at room temperature for 30 minutes, and subjected to hydrothermal reaction at 220 ℃ for 8 hours to prepare MIL-101 (Cr).

3. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: the concentration of the polymer solution was 18%.

4. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: the solvent is N, N-dimethylformamide.

5. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: a certain amount of N, N-dimethylformamide as a solvent was weighed, and a certain amount of MIL-101(Cr) was added successively.

6. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: solutions of MIL-101(Cr) in N, N-dimethylformamide require sonication.

7. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: mechanical stirring was required for 10 hours after addition of polymer P84.

8. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: the obtained 18% P84/MIL-101(Cr) casting solution needs to be kept still for defoaming treatment.

9. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: the 18% P84/MIL-101(Cr) casting solution required phase inversion in the coagulation bath deionized water.

10. The method of claim 1 for preparing a P84/MIL-101(Cr) mixed matrix film, wherein: the P84/MIL-101(Cr) mixed matrix film is used for removing the mixed dye of methyl orange and methylene blue.

Technical Field

The invention relates to the field of water treatment membrane separation, and relates to a preparation method of a polyimide P84/MIL-101(Cr) mixed matrix membrane.

Technical Field

The pollution of water sources by toxic compounds such as dyes, heavy metal ions and the like is one of the serious environmental problems facing the world today, and dyes are widely used in the paper, rubber, textile and textile industries all over the world, are stable to heat, oxidants and light, and their presence in waste water disturbs the biodegradation stability of aquatic organisms, and therefore, it is crucial to remove the dyes from industrial waste water before they are released into the environment. Wherein, the membrane separation technology has the characteristics of low energy consumption, small pollution, energy conservation, environmental protection and the like and is widely applied to sewage treatment.

High molecular polymer membranes have limited applications due to permeability and selectivity tradeoffs, and for this reason mixed matrix membranes have the dual advantage of dispersing filler and polymer with the hope of overcoming the above limitations. The MOFs (metal organic frameworks) is a process of self-assembly of metal ions and organic ligands, and has the advantages of developed porosity, adjustable pore size, high specific surface area, easy functionalization and the like.

MIL-101(Cr) is used as a dispersion filler, and compared with an inorganic nano filler, the nano filler has organic functional groups and has higher compatibility with polymers because of the natural existence of the inorganic nano filler. MIL-101(Cr) is a hydrophilic MOFs material with high specific surface area, mesopores and self-assembled by metal chromium and terephthalic acid, and based on the MOFs material, the invention provides a mixed matrix membrane which takes polyimide P84 as a polymer continuous phase and MIL-101 as a disperse phase and is used for removing mixed dyes of methyl orange and methylene blue.

Disclosure of Invention

The invention aims to solve the problem that dye solution with small molecular weight is difficult to process due to the defects of time consumption and cost for removing dye by pure MIL-101(Cr), and the like, and the method provides that the MIL-101(Cr) is doped with polyimide P84 to prepare a mixed matrix film for removing methyl orange and methylene blue mixed dye.

The invention comprises the following steps:

1. 4.000 g of chromium nitrate nonahydrate, 1.660 g of terephthalic acid and 48 ml of water are stirred at room temperature for 30 minutes, and hydrothermal reaction is carried out at 220 ℃ for 8 hours to prepare MIL-101 (Cr);

2. putting MIL-101(Cr) with the solid content of 0-20% into a three-neck flask, adding a certain amount of solvent N, N-dimethylformamide, carrying out ultrasonic treatment for 60 minutes to obtain a suspension of MIL-101(Cr), adding 6 g of polymer P84 granules into the suspension of MIL-101(Cr), stirring for 10 hours at room temperature, standing overnight for defoaming, and preparing 18% P84/MIL-101 casting solution;

3. pouring the casting solution on a clean glass plate, scraping the film by using a 200-micron scraper, immediately transferring the film into deionized water (room temperature), and performing phase conversion to obtain a P84/MIL-101 mixed matrix film;

as a preferable scheme, the preparation method of the P84/MIL-101(Cr) mixed matrix film is characterized in that the solid content of the MIL-101(Cr) in the preferable step (2) is 0-20%;

as a preferable scheme, the preparation method of the P84/MIL-101(Cr) mixed matrix film is characterized in that the preferable step (2) is that the MIL-101(Cr) is subjected to ultrasonic treatment in N, N-dimethylformamide as a solvent for 60 minutes;

as a preferred scheme, the preparation method of the P84/MIL-101(Cr) mixed matrix film is characterized in that the preferred step (2) is to add 6 g of particles of the polymer P84 and stir the mixture for 10 hours at room temperature;

as a preferable scheme, the preparation method of the P84/MIL-101(Cr) mixed matrix film is characterized in that the P84/MIL-101(Cr) mixed matrix film is used for removing the mixed dye of methyl orange and methylene blue.

Compared with the prior art, the invention has the following characteristics:

1. the preparation method is simple, consumes less time and consumes less resources;

P84/MIL-101(Cr) mixed matrix film, wherein MIL-101(Cr) is uniformly dispersed in polyimide P84;

3. the metal framework mixed matrix membrane of the polyimide P84 has excellent application prospect for removing dye;

4. the P84/MIL-101(Cr) mixed matrix film has excellent removal capability of mixed dyes of methyl orange and methylene blue.

Description of the drawings:

FIG. 1 is a scanning electron micrograph of MIL-101(Cr) prepared in example 1;

FIG. 2 is a scanning electron micrograph of the surface of the P84/MIL-101(Cr) -20% mixed matrix film prepared in example 1;

FIG. 3 is an X-ray diffraction pattern of a P84/MIL-101(Cr) -20% mixed matrix film prepared in example 1;

FIG. 4 is an EDS power spectrum element distribution plot of the P84/MIL-101(Cr) -20% mixed matrix film prepared in example 1;

FIG. 5 is a graph of the dye removal UV for the P84/MIL-101(Cr) -20% mixed matrix film prepared in example 1.

The specific implementation method comprises the following steps:

while the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Example 1 comprises the following steps:

1. 4.000 g of chromium nitrate nonahydrate, 1.660 g of terephthalic acid and 48 ml of water are stirred at room temperature for 30 minutes, and hydrothermal reaction is carried out at 220 ℃ for 8 hours to prepare MIL-101 (Cr);

2. putting MIL-101(Cr) with the solid content of 20% into a three-neck flask, adding a certain amount of solvent N, N-dimethylformamide, carrying out ultrasonic treatment for 60 minutes to obtain a suspension of MIL-101(Cr), adding 6 grams of polymer P84 granules into the suspension of MIL-101(Cr), mechanically stirring for 10 hours at room temperature, standing overnight for deaeration, and preparing 18% P84/MIL-101-20% casting solution;

3. pouring the casting solution on a clean glass plate, scraping the film by using a 200 micron scraper, immediately transferring the film into deionized water (room temperature), and carrying out phase inversion to obtain a P84/MIL-101-20% mixed matrix film.

The SEM of the material prepared in example 1 is shown in FIG. 1, and FIG. 1 is the SEM of MIL-101 (Cr). FIG. 2 is a surface scanning electron microscope image of the P84/MIL-101-20% mixed matrix film. Comparing fig. 1 and 2, it can be seen that MIL-101(Cr) was successfully incorporated into polyimide P84 and that the octahedral structure of MIL-101(Cr) was exhibited simultaneously with the P84/MIL-101-20% mixed matrix film;

the X-ray diffraction pattern of the membrane material prepared in example 1 is shown in FIG. 3, the X-ray diffraction pattern of synthesized MIL-101(Cr) is matched with a standard vertebral spectrogram, the synthesis success of MIL-101(Cr) is proved, meanwhile, the diffraction peaks of the X-ray diffraction pattern of the P84/MIL-101-20% mixed matrix membrane and the X-ray diffraction pattern of the MIL-101(Cr) at 8.2, 9.0 and 16.3 are consistent with the diffraction peaks of (228), (135) and (5913) surfaces, and the MIL-101(Cr) is proved to be successfully compounded with the polyimide P84;

the EDS energy spectrum element distribution diagram of the membrane material prepared in the example 1 is shown in a figure 4, the MIL-101(Cr) and polyimide P84 composite membrane material mainly comprises carbon, oxygen, chromium and nitrogen, and the nitrogen element is derived from polyimide P84 due to the fact that the synthesized MIL-101(Cr) does not contain the nitrogen element, and the P84/MIL-101(Cr) composite is successful by combining the characteristics;

the ultraviolet removal pattern of the mixed dye of the material prepared in example 1 is shown in fig. 5, and the removal rate of the mixed dye of methylene blue and methyl orange of the P84/MIL-101-20% mixed matrix film calculated from fig. 5 reaches 97.48% and 84.49%.