Polymer modified cyclodextrin MOFs material, preparation method thereof and capillary electrophoresis chiral separation method

Abstract

The application discloses a kind of polymer modified cyclodextrin MOFs material and its preparation method and capillary electrophoresis chiral separation method.The method first disperses polymer (for example styrene monomer) and cyclodextrin MOFs in organic solvent, adds initiator by the method of ultraviolet light irradiation initiation, and the preparation obtains polystyrene modified cyclodextrin MOFs material.The polystyrene modified cyclodextrin MOFs material prepared in the application is uniformly dispersed, and particle size is 200-400nm.Further, it is dispersed in chloroform solution, is coated into capillary by being inhaled, and using capillary electrophoresis can realize the chiral separation of amino acid enantiomer.The preparation method of the application is simple and easy to operate, low in cost, and raw material is cheap and easy to obtain, has potential application in the field of drug molecules and amino acid biological drug separation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chiral separation, and relates to a polymer-modified cyclodextrin MOFs material, a preparation method thereof and a capillary electrophoresis chiral separation method, in particular to a polymer-modified cyclodextrin MOFs, a preparation method thereof and application of the polymer-modified cyclodextrin MOFs in a capillary electrophoresis chiral separation method, and especially to preparation of a polymer-modified cyclodextrin MOFs material and application of the polymer-modified cyclodextrin MOFs material as a coating in capillary electrophoresis separation of amino acid enantiomers. BACKGROUND

[0002] The cyclodextrin MOFs are novel porous materials, which not only have excellent adsorption performance and catalytic activity, but also have excellent chiral separation performance, chemical stability and pore size distribution. Based on the above excellent characteristics, the cyclodextrin MOFs have wide application prospects in many fields (for example, gas adsorption, catalysts, drug separation, water treatment and biosensors, etc.).

[0003] In these applications, the cyclodextrin MOFs have special advantages in chiral separation. Chiral separation refers to the process of separating different chiral structures of a substance. For chiral separation, the most commonly used method is based on stereoselective adsorption, that is, using the stereoselective adsorption of chiral molecules on the surface of chiral materials. The cyclodextrin MOFs can effectively adsorb and separate substances with different chiral structures due to their unique structure and surface properties, and therefore have great application potential in chiral separation.

[0004] However, so far, a new cyclodextrin MOFs material with multi-level chiral recognition ability has not been developed, and the cyclodextrin MOFs have the disadvantages of being easily decomposed by water and not being easy to be modified on the inner wall of a capillary or a chromatographic separation medium when applied as a chiral separation material in chromatographic separation, thereby greatly limiting its application in separation and analysis in the chromatographic field. This may be due to: (1) the synthesis cycle of the cyclodextrin MOFs reported at present is relatively long, and it takes tens of days to obtain the product, and the reproducibility of the material preparation is poor; (2) the method for modifying the cyclodextrin MOFs on the surface of the chromatographic packing is not mature, which limits its wide application. Therefore, it is of great significance to modify the cyclodextrin MOFs material at present.

[0005] Polymer materials have multifunctional reactive groups, and some special polymers have good film-forming properties, while the flexible structure of the polymer itself can greatly improve the plasticity and ductility of the rigid structure of cyclodextrin MOFs, making it have the characteristics of reprocessing. Therefore, the preparation strategy of constructing rigid-flexible combined materials, and synthesizing polymer-protected cyclodextrin MOFs is a potential research direction. In the future, through further research and development of cyclodextrin MOFs, more progress can be expected in the field of chiral separation, and contribute to the development of drug manufacturing, food processing and fine chemical industry. SUMMARY

[0006] In order to improve the above technical problems, the present application provides a novel polystyrene modified cyclodextrin MOFs chiral separation material and its preparation method and capillary electrophoresis chiral separation method, the polystyrene modified cyclodextrin MOFs material of the present application has good film-forming property and excellent chiral separation ability.

[0007] In order to achieve the above-mentioned application purposes, the present application adopts the following technical solutions:

[0008] A cyclodextrin MOFs composite material comprises cyclodextrin MOFs and a polymer modified on the cyclodextrin MOFs. Preferably, in the composite material, the polymer penetrates the cyclodextrin MOFs.

[0009] According to an embodiment of the present application, the particle size of the composite material is 200-400 nm, for example, 230 nm, 280 nm, 350 nm, 390 nm, or 400 nm.

[0010] According to an embodiment of the present application, the cyclodextrin MOFs are MOFs prepared from γ-cyclodextrin; preferably, the cyclodextrin MOFs are MOFs prepared from γ-cyclodextrin and potassium ions or other metal ions.

[0011] According to an embodiment of the present application, the polymer is selected from one or more than two kinds of mixture of polystyrene, polymaleic anhydride, and poly(N-isopropyl acrylamide).

[0012] According to an embodiment of the present application, the composite material is obtained by polymerization reaction of polymer monomers and cyclodextrin MOFs under the action of an initiator and under light irradiation to obtain a polymer-modified cyclodextrin MOFs material.

[0013] According to an embodiment of the present application, the polymer monomer can be one or more than two kinds of mixture of styrene, maleic anhydride, and N-isopropyl acrylamide.

[0014] According to an embodiment of the present application, the mass ratio of the polymer monomer to the cyclodextrin MOFs is 1:0.05-1:0.1, exemplarily 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1.

[0015] According to an embodiment of the present application, the initiator is, for example, azobisisobutyronitrile. Preferably, the amount of the initiator is 1%-3% of the amount of the polymer monomer, exemplarily 1%, 1.5%, 2%, 2.5%, 3%.

[0016] The present application also provides a preparation method of the composite material, which comprises initiating a polymerization reaction of the polymer monomer and the cyclodextrin MOFs under the action of an initiator and under irradiation to obtain the polymer-modified cyclodextrin MOFs material.

[0017] According to an embodiment of the present application, the polymer monomer, the cyclodextrin MOFs and the initiator have the selections and definitions as described above.

[0018] According to an embodiment of the present application, the cyclodextrin MOFs are added into the reaction system in the form of a solution. For example, the cyclodextrin MOFs are dispersed in an organic solvent to obtain a cyclodextrin MOFs solution, which is then mixed with the polymer monomer and the initiator to obtain a reaction liquid. For example, the organic solvent is 1,4-dioxane, tetrahydrofuran or the like.

[0019] In an embodiment of the present application, the concentration of the cyclodextrin MOFs solution is 1-10 mg / mL, exemplarily 1 mg / mL, 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 10 mg / mL.

[0020] According to an embodiment of the present application, the polymer monomer is preferably added into the cyclodextrin MOFs solution in the form of dropwise addition. For example, the polymer monomer is added dropwise into the cyclodextrin MOFs solution under stirring.

[0021] According to an embodiment of the present application, the preparation method further comprises removing oxygen from the reaction liquid. For example, the oxygen in the reaction liquid is removed by a method of freeze circulation. Exemplarily, the method of removing oxygen is to freeze the reaction liquid by using liquid nitrogen, to vacuumize, to fill nitrogen and to repeat the circulation for three times.

[0022] According to an embodiment of the present application, the preparation method further comprises ultrasonic treatment of the reaction liquid after oxygen removal. Preferably, the time of the ultrasonic treatment is 20-40 minutes, exemplarily 20 minutes, 30 minutes, 40 minutes.

[0023] According to an embodiment of the present application, the irradiation is performed using ultraviolet light. For example, the irradiation is performed using ultraviolet light with a wavelength of 254 nm. Preferably, the irradiation is performed for 6-24 hours. For example, the irradiation is performed for 6 hours, 8 hours, 10 hours, 12 hours, or 24 hours.

[0024] According to an embodiment of the present application, the preparation method further comprises centrifuging, washing, and drying the polymer-modified cyclodextrin MOFs material after the reaction is completed. Preferably, the drying is performed at room temperature or at a temperature of 30-50°C.

[0025] According to an embodiment of the present application, the preparation method of the composite material comprises the following steps:

[0026] (1) dispersing the cyclodextrin MOFs material in an organic solvent to obtain a cyclodextrin MOFs solution;

[0027] (2) adding a polymer monomer solution and an initiator to the cyclodextrin MOFs solution obtained in step (1);

[0028] (3) removing oxygen in the reaction solution by a freeze-thaw cycle;

[0029] (4) ultrasonicating and irradiating the polymer reaction with ultraviolet light;

[0030] (5) centrifuging, washing, and drying the target product after the reaction is completed.

[0031] During the reaction: after ultrasonic dispersion, the polymer monomer is first dispersed in the pore size of the cyclodextrin MOFs, and after the addition of the initiator, the polymer monomer in the pore size and the polymer monomer in the solution are co-polymerized to obtain the polymer-modified nanomaterials penetrating the cyclodextrin MOFs.

[0032] The present application also provides the use of the cyclodextrin MOFs composite material in capillary electrophoresis separation. Preferably, the use in capillary electrophoresis chiral separation. For example, the cyclodextrin MOFs composite material is used as a coating to modify the inner wall of a capillary for separating chiral substances.

[0033] According to an embodiment of the present application, the chiral substance is an amino acid chiral enantiomer or a drug molecule. For example, one or a mixture of two of the chiral enantiomers of methionine, serine, histidine, phenylalanine, and derivatives thereof.

[0034] The present application also provides a capillary electrophoresis chiral separation method using the cyclodextrin MOFs composite material. The method comprises using the cyclodextrin MOFs composite material as a coating to modify the inner wall of a capillary, and separating chiral substances.

[0035] According to an embodiment of the present application, the method for modifying the inner wall of a capillary tube with a cyclodextrin MOFs composite as a coating is: injecting a cyclodextrin MOFs composite solution into the capillary tube. For example, the injection flow rate of the cyclodextrin MOFs composite solution is 0.1-0.5 mL / h, and exemplary values are 0.1 mL / h, 0.3 mL / h, and 0.5 mL / h.

[0036] According to an embodiment of the present application, the concentration of the cyclodextrin MOFs composite solution is 0.5 mg / mL-2.0 mg / mL, for example 0.5 mg / mL, 1.0 mg / mL, 1.5 mg / mL, or 2.0 mg / mL.

[0037] Advantages of the present application:

[0038] Cyclodextrin MOFs are a new type of organic composite material, and have excellent adsorption performance and a large specific surface area. Therefore, in recent years, cyclodextrin MOFs have been successfully applied in the fields of redox reactions, methanol dehydrogenation reactions, and adsorption of pollutants. However, in the field of chiral separation, research on cyclodextrin MOFs is still relatively limited. The main reasons for this are as follows: (1) the synthesis and preparation method of cyclodextrin MOFs is lengthy, and generally requires a synthesis time of 7-8 days; (2) cyclodextrin MOFs materials have poor stability, and can decompose in water and cannot tolerate acids and bases; (3) cyclodextrin MOFs materials have good chiral separation ability, but do not have a binding group that can be covalently bonded to a chromatographic separation medium. Among polymer materials, polystyrene has good film-forming properties and controllable polymerization properties. In view of this:

[0039] (1) The present application combines a polymer (for example, polystyrene) with cyclodextrin MOFs to prepare a polymer@cyclodextrin MOFs hybrid material, which not only has the excellent chiral separation ability of cyclodextrin MOFs, but also can take advantage of the film-forming properties of polystyrene to prepare a chiral separation medium that can be modified to the inner wall of a capillary tube, thereby achieving capillary electrophoresis separation of chiral molecules. The present application improves the film-forming ability and bonding properties of cyclodextrin MOFs to chromatographic separation media by modifying cyclodextrin MOFs with polystyrene, and explores new strategies for synthesis and preparation of the material, and studies its application in separation of chiral drugs.

[0040] (2) the styrene monomer enters the inside of the cyclodextrin MOF channel after ultrasonic, and the initiator is added to initiate polymerization under light to obtain a polymer modified cyclodextrin MOF material. The good film-forming property of polystyrene can be used to uniformly coat the inner wall of the capillary. The styrene modified cyclodextrin MOF has good chiral separation capacity, and after being coated on the inner wall of the capillary, it can be used as a coating column for capillary electrophoresis separation, and the chiral separation of amino acid enantiomers can be realized. The method overcomes the problems that the unmodified cyclodextrin MOF cannot be uniformly coated on the inner wall of the capillary because the cyclodextrin MOF does not have film-forming property, and the cyclodextrin MOF cannot maintain the chiral separation capacity because it is decomposed in the buffer solution. The polystyrene modified cyclodextrin MOF obtained by the method can protect the material from being decomposed during chiral separation in capillary electrophoresis separation, and also provides a polymer that can be uniformly coated on the inner wall of the capillary.

[0041] (3) The polystyrene modified cyclodextrin MOF samples are prepared by different modification methods, and the chiral separation performance of the materials is studied through experiments, and the chiral separation mechanism is analyzed. Meanwhile, the materials are applied to actual chiral separation, and the performance is evaluated, so as to contribute to the development of new chiral separation materials and methods.

[0042] (4) The polystyrene modified cyclodextrin MOF prepared by the polystyrene@cyclodextrin MOF composite material preparation method provided by the application is prepared by ultraviolet light induced polymerization, which can prevent the uneven particle size distribution caused by the violent initiation of styrene polymerization, and has low preparation cost and simple operation, which embodies the significance of green chemistry.

[0043] (5) Compared with the liquid chromatography filler coating for realizing chiral separation of substances, the coating tube separation technology based on capillary electrophoresis constructed by the application has the advantages of small amount of composite material, only microliter coating solution is needed to coat the inner wall of the capillary, so the cost of the chiral separation composite material can be greatly reduced; at the same time, the chiral separation technology based on capillary electrophoresis has the advantages of small sample amount (the sample solution is in nanoliter), which provides an irreplaceable separation tool for the separation of trace or trace chiral substances.

[0044] (6) The polystyrene@cyclodextrin MOF composite material preparation method constructed by the application has universality, and can be applied to the preparation of various chiral MOF bonded polymers and capillary electrophoresis coating chiral separation. Polystyrene can be replaced by other types of polymers, which can take into account the film-forming property on the one hand, and can be mixed into a multifunctional polymer block on the other hand, so as to improve the performance advantages of the polymer@MOF composite material. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1Schematic diagram of chiral separation using the chiral stationary phase of polystyrene modified cyclodextrin MOFs prepared in Example 1;

[0046] Figure 2 Particle size distribution diagram of polystyrene modified cyclodextrin MOFs (polystyrene@MOFs) prepared in Example 1;

[0047] Figure 3 XRD patterns of polystyrene modified cyclodextrin MOFs prepared in Example 1 before and after modification;

[0048] Figure 4 FT-IR spectrum of polystyrene modified cyclodextrin MOFs prepared in Example 1;

[0049] Figure 5 SEM spectrum of polystyrene modified cyclodextrin MOFs prepared in Example 1;

[0050] Figure 6 Capillary electrophoresis amino acid chiral separation diagram of polystyrene modified cyclodextrin MOFs prepared in Example 1.

[0051] Figure 7 Capillary electrophoresis amino acid chiral separation diagram of polystyrene modified cyclodextrin MOFs prepared in Examples 2-5.

[0052] Figure 8 Capillary electrophoresis amino acid chiral separation diagram of polystyrene modified cyclodextrin MOFs prepared in Example 6. DETAILED DESCRIPTION

[0053] The technical solutions of the present application will be further described in detail below in combination with specific examples. It should be understood that the following examples are only illustratively and explain the present application, and should not be interpreted as limiting the scope of protection of the present application. Any technology realized based on the above description of the present application is covered within the scope of protection intended by the present application.

[0054] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0055] Example 1

[0056] The preparation method of polystyrene modified cyclodextrin MOFs comprises the following steps:

[0057] (1) 50 mg of cyclodextrin MOFs (purchased from Xi'an Ruishi Biological Technology Co., Ltd.) was dispersed in 10 mL of 1,4-dioxane;

[0058] (2) Add styrene monomer (1.0 g) and initiator azobisisobutyronitrile (10 mg) and ultrasonic dispersion for 30 minutes;

[0059] (3) The oxygen in the reaction solution was removed by a freezing cycle method (first, the reaction solution was frozen into a solid by using liquid nitrogen, then a vacuum pump was used to extract the vacuum for 3 minutes, then the vacuum system was closed and nitrogen was introduced, and the solution was slowly warmed and melted. This operation was repeated three times);

[0060] (4) After ultrasonic treatment for 30 minutes, the polymer reaction was initiated by ultraviolet light and continuously irradiated for 12 hours;

[0061] (5) After the reaction was completed, centrifugation (at a speed of 10,000 r / min), 1,4-dioxane washing, and drying at 50°C for 10h, polystyrene modified cyclodextrin MOFs (polystyrene@MOFs, PS-CDMOF) were obtained.

[0062] Figure 2 The particle size distribution graph of the polystyrene@MOFs prepared in this example, from the results, it can be seen that the polystyrene@MOFs prepared in this example was not decomposed after ultrasonic dispersion in water (concentration of 1.0 mg / mL), the particle size was about 200 nm, and the particle size was uniformly dispersed, thereby proving that the polystyrene was successfully modified to the cyclodextrin MOFs, thereby inhibiting the decomposition of the cyclodextrin MOFs in water.

[0063] Figure 3 The XRD patterns of the polystyrene modified cyclodextrin MOFs prepared in this example before (the product of step (1) CDMOF) and after modification (PS-CDMOF), from the results in the figure, it can be seen that the crystal structure of the cyclodextrin MOFs was not destroyed before and after the modification by polystyrene, and the polystyrene was successfully modified to the cyclodextrin MOFs.

[0064] Figure 4 The FT-IR spectrum of the polystyrene modified cyclodextrin MOFs prepared in Example 1; from the figure, it can be seen that the peak value at 1596 cm -1 is the characteristic peak of the C=C of styrene, and the characteristic peak at 2919 cm -1 corresponds to the C-H stretching vibration of the methylene on PS. Thus, it is proved that the polystyrene modified cyclodextrin MOFs composite material is successfully prepared.

[0065] Figure 5 The SEM spectrum of the polystyrene modified cyclodextrin MOFs prepared in Example 1; from the figure, it can be seen that after the polystyrene is modified, the MOFs still maintains its solid structure and is not destroyed in the modification process.

[0066] Example 2

[0067] The preparation method of the polystyrene modified cyclodextrin MOFs comprises the following steps:

[0068] (1) dispersing the cyclodextrin MOFs (60 mg) in 10 mL of 1,4-dioxane;

[0069] (2) adding styrene monomer (1.0 g) and initiator azobisisobutyronitrile (15 mg) and ultrasonically dispersing for 30 minutes;

[0070] (3) removing oxygen in the reaction solution by means of a freeze cycle (first freezing the reaction solution into a solid using liquid nitrogen, then vacuum pumping for 3 minutes, then closing the vacuum system and introducing nitrogen to slowly warm and melt the solution. This operation is repeated three times);

[0071] (4) after ultrasonic dispersion for 30 minutes, initiating the polymerization reaction by ultraviolet light and continuously irradiating for 24 hours;

[0072] (5) after the reaction is completed, centrifuging (at a speed of 10,000 r / min), washing with 1,4-dioxane, and drying at 50°C for 10 h to obtain the polystyrene-modified cyclodextrin MOFs.

[0073] Example 3

[0074] A method for preparing polystyrene-modified cyclodextrin MOFs comprises the following steps:

[0075] (1) dispersing the cyclodextrin MOFs (70 mg) in 10 mL of 1,4-dioxane;

[0076] (2) adding styrene monomer (1.0 g) and initiator azobisisobutyronitrile (20 mg) and ultrasonically dispersing for 30 minutes;

[0077] (3) removing oxygen in the reaction solution by means of a freeze cycle (first freezing the reaction solution into a solid using liquid nitrogen, then vacuum pumping for 3 minutes, then closing the vacuum system and introducing nitrogen to slowly warm and melt the solution. This operation is repeated three times);

[0078] (4) after ultrasonic dispersion for 30 minutes, initiating the polymerization reaction by ultraviolet light and continuously irradiating for 36 hours;

[0079] (5) after the reaction is completed, centrifuging (at a speed of 10,000 r / min), washing with 1,4-dioxane, and drying at 50°C for 10 h to obtain the polystyrene-modified cyclodextrin MOFs.

[0080] Example 4

[0081] A method for preparing polystyrene-modified cyclodextrin MOFs comprises the following steps:

[0082] (1) dispersing the cyclodextrin MOFs (80 mg) in 10 mL of 1,4-dioxane;

[0083] (2) adding styrene monomer (1.0 g) and initiator azobisisobutyronitrile (25 mg) and ultrasonic dispersion for 30 minutes;

[0084] (3) removing oxygen in the reaction solution by using a freeze-thaw cycle method (firstly, using liquid nitrogen to freeze the reaction solution into a solid, then using a vacuum pump to extract vacuum for 3 minutes, then closing the vacuum system to introduce nitrogen, and slowly heating and melting the solution. This operation is repeated three times);

[0085] (4) after ultrasonic dispersion for 30 minutes, initiating the polymerization reaction by ultraviolet light and continuously irradiating for 6 hours;

[0086] (5) after the reaction is completed, centrifuging, washing, and drying at 50°C for 10 hours to obtain the polystyrene modified cyclodextrin MOFs.

[0087] Example 5

[0088] The preparation method of the polystyrene modified cyclodextrin MOFs comprises the following steps:

[0089] (1) dispersing cyclodextrin MOFs (100 mg) in 10 mL of 1,4-dioxane;

[0090] (2) adding styrene monomer (1.0 g) and initiator azobisisobutyronitrile (15 mg) and ultrasonic dispersion for 30 minutes;

[0091] (3) removing oxygen in the reaction solution by using a freeze-thaw cycle method (firstly, using liquid nitrogen to freeze the reaction solution into a solid, then using a vacuum pump to extract vacuum for 3 minutes, then closing the vacuum system to introduce nitrogen, and slowly heating and melting the solution. This operation is repeated three times);

[0092] (4) after ultrasonic dispersion for 30 minutes, initiating the polymerization reaction by ultraviolet light and continuously irradiating for 12 hours;

[0093] (5) after the reaction is completed, centrifuging (at a speed of 10,000 r / min), 1,4-dioxane washing, and drying at 50°C for 10 hours to obtain the polystyrene modified cyclodextrin MOFs.

[0094] Example 6

[0095] Using the polystyrene modified cyclodextrin MOFs prepared in Example 1 as a coating material, a capillary chiral coating and an amino acid chiral separation method are constructed:

[0096] Before coating the capillary, the capillary needs to be activated first. Washing with methanol for 10-15 minutes, then washing with deionized water for 2-5 minutes, then washing with 0.1M NaOH for 15-30 minutes, and finally washing with deionized water for 2-5 minutes, and then washing with chloroform for 2-5 minutes.

[0097] A 1.0 mg / mL solution of polystyrene-modified cyclodextrin MOFs was prepared in chloroform, and was slowly injected into a capillary tube with a length of 20 cm and an inner diameter of 75 μm at a flow rate of 0.3 mL / h from a syringe until continuous droplets were dropped at the other end. After the polystyrene-modified cyclodextrin MOFs were injected into the capillary tube, the capillary tube was blown dry with nitrogen, and a thin film was formed on the wall of the blown-dry capillary tube (attention should be paid during the coating process, as too fast injection may result in uneven coating, and too slow injection may affect the coating effect). Finally, a capillary chiral column coated with polystyrene-modified cyclodextrin MOFs was obtained.

[0098] In order to determine the chiral separation performance of the polystyrene-modified cyclodextrin MOFs, 25 mM sodium tetraborate and 5 mg / L SDS were used as the buffer, Dns-DL-Met (a derivative obtained by derivatizing methionine with dansyl chloride) was used as the separation object, the high-difference (15 cm) injection method was used, the injection amount was 10 s, and the chiral separation capacity of the polystyrene-modified cyclodextrin MOFs was tested. The chiral separation capacity of the coated capillary tube with an effective length of 20 cm and an inner diameter of 75 μm was tested under the condition of a separation voltage of 10 kV, and the chiral separation result is shown in FIG. 2. Figure 6 The results show that the polystyrene-modified cyclodextrin MOFs can be successfully coated on the inner wall of the capillary tube, and the chiral separation of the chiral amino acid is achieved, and the polystyrene-modified cyclodextrin MOFs have good chiral separation capacity.

[0099] Example 7

[0100] Capillary electrophoresis separation condition screening and sample preparation: Chiral amino acid Dns-DL-Met was used as the sample, and the chiral separation capacity of the capillary chiral column coated with the polystyrene-modified cyclodextrin MOFs prepared in Examples 2-5 as the coating material was investigated. The experimental method was as follows:

[0101] The polystyrene-modified cyclodextrin MOF samples prepared in Examples 2-5 were respectively dissolved in chloroform solvent to prepare a 1.0 mg / mL suspension, and were slowly injected into a capillary tube with a length of 20 cm and an inner diameter of 75 μm at a flow rate of 0.3 mL / h from a syringe. After the polystyrene-modified cyclodextrin MOFs were injected into the capillary tube, the capillary tube was blown dry with nitrogen, and a thin film was formed on the wall of the blown-dry capillary tube, and finally a capillary chiral column coated with polystyrene-modified cyclodextrin MOFs was obtained.

[0102] The chiral separation ability of the polystyrene modified cyclodextrin MOFs prepared in Examples 2-5 (CDMOFs are 60.0 mg, 70.0 mg, 80.0 mg, 100.0 mg, respectively) was tested by using 25 mM sodium tetraborate and 5 mg / L SDS as buffer, using Dns-DL-Met (a derivative obtained by using dansyl chloride to derivatize methionine) as separation object, using high difference (15 cm) injection method, and using 10 s injection amount. The chiral separation ability of a coated capillary with an effective length of 20 cm and an inner diameter of 75 μm was tested under the condition of a separation voltage of 10 kV, and the chiral separation result is shown in Figure 7 The results show that the polystyrene modified cyclodextrin MOFs can be successfully coated on the inner wall of the capillary, and the chiral separation of the chiral amino acid is realized, and changing the mass ratio of the polymer monomer and the cyclodextrin MOFs will affect the chiral separation ability of the prepared polystyrene modified cyclodextrin MOFs.

[0103] Example 8

[0104] Stability test experiment of polystyrene modified cyclodextrin MOFs coated capillary electrophoresis: the polystyrene modified cyclodextrin MOFs prepared in Example 1 were modified on the inner wall of the capillary by using the physical coating method constructed in Example 6, and the chiral separation of the chiral amino acid Dns-DL-Met was carried out by using the separation method in Example 7 (the separation voltage was 10 kV, and the capillary column length was 20 cm, and the inner diameter was 75 μm), and the result is shown in Figure 8 From the figure, it can be seen that the chiral separation ability of the polystyrene modified cyclodextrin MOFs coated capillary column does not obviously decrease after being continuously tested for ten times. Thus, it is shown that the reusability and stability of the polystyrene modified cyclodextrin MOFs coated capillary column chiral stationary phase prepared in the present application are good.

[0105] The above describes the embodiments of the present application. However, the present application is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cyclodextrin MOFs composite material, characterized in that, The complex material comprises a cyclodextrin MOF and a polymer modified on the cyclodextrin MOF, wherein the polymer is threaded through the cyclodextrin MOF, and the polymer is selected from polystyrene.

2. The cyclodextrin MOFs composite material of claim 1, wherein, The particle size of the complex material is 200-400 nm. The cyclodextrin MOF is an MOF prepared from γ-cyclodextrin.

3. The cyclodextrin MOFs composite material of claim 2, wherein, The cyclodextrin MOF is an MOF prepared from γ-cyclodextrin and potassium ions or other metal ions.

4. The cyclodextrin MOFs composite material according to any one of claims 1-3, wherein, The complex material is prepared by polymerization of a polymer monomer and the cyclodextrin MOF under the action of an initiator and under irradiation to obtain a polymer-modified cyclodextrin MOF material.

5. The cyclodextrin MOF composite of claim 4, wherein The polymer monomer is styrene. The mass ratio of the polymer monomer to the cyclodextrin MOF is 1:0.05-1:0.

1.

6. The cyclodextrin MOFs composite material of claim 4, wherein, The initiator is azobisisobutyronitrile. The amount of the initiator is 1%-3% of the amount of the polymer monomer.

7. A method of preparing the cyclodextrin MOF composite material according to any one of claims 1 to 6, characterized in that, The preparation method comprises the following steps: polymerization of a polymer monomer and the cyclodextrin MOF under the action of an initiator and under irradiation to obtain a polymer-modified cyclodextrin MOF material.

8. The production method according to claim 7, wherein The cyclodextrin MOF is added to the reaction system in the form of a solution, the cyclodextrin MOF is dispersed in an organic solvent to obtain a cyclodextrin MOF solution, and then the cyclodextrin MOF solution is mixed with the polymer monomer and the initiator to obtain a reaction liquid; the organic solvent is 1,4-dioxane or tetrahydrofuran.

9. The production method according to claim 8, wherein The concentration of the cyclodextrin MOF solution is 1-10 mg / mL. The polymer monomer is added to the cyclodextrin MOF solution in the form of drops.

10. The production method according to claim 7, wherein The irradiation is performed by using ultraviolet light, and the irradiation time is 6-24 hours.

11. The production method according to any one of claims 7 to 10, wherein The preparation method of the complex material comprises the following steps: (1) dispersing the cyclodextrin MOF material in an organic solvent to obtain a cyclodextrin MOF solution; (2) adding a polymer monomer solution and an initiator to the cyclodextrin MOF solution of step (1); (3) removing oxygen in the reaction liquid by using a freeze-thaw cycle method; (4) ultrasonic irradiation initiates the polymerization reaction; (5) after the reaction is completed, centrifugation, washing and drying are performed to obtain the target product.

12. Application of the cyclodextrin MOF complex material of any one of claims 1-6 and / or the cyclodextrin MOF complex material prepared by the preparation method of any one of claims 7-11 in capillary electrophoresis separation.

13. Use according to claim 12, wherein The cyclodextrin MOF complex material is applied in capillary electrophoresis chiral separation.

14. Use according to claim 13, wherein the compound is ###0002### The cyclodextrin MOF complex material is used as a coating to modify the inner wall of a capillary for separating chiral substances.

15. The use according to claim 14, wherein the compound is ###0002### The chiral substance is an amino acid chiral enantiomer or a drug molecule.

16. The use according to claim 15, characterized in that The chiral substance is one of methionine, serine, histidine and phenylalanine, or a mixture of two thereof.

17. A capillary electrophoresis chiral separation method of the cyclodextrin MOFs composite material of any one of claims 1-6 and / or the cyclodextrin MOFs composite material prepared by the preparation method of any one of claims 7-11, characterized in that, The cyclodextrin MOF complex material is used as a coating to modify the inner wall of a capillary for separating chiral substances.

18. The method of claim 17, wherein, The method for using the cyclodextrin MOF complex material as a coating to modify the inner wall of a capillary comprises: injecting a cyclodextrin MOF complex material solution into the capillary.

19. The method of claim 18, wherein, The concentration of the cyclodextrin MOFs composite solution is 0.5 mg / mL-2.0 mg / mL. The concentration of the cyclodextrin MOFs composite solution is 0.5 mg / mL-2.0 mg / mL.

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