Pentafluorobenzyl functionalized covalent organic framework material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of material preparation, and particularly relates to a pentafluorobenzyl functionalized covalent organic framework material as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly, preparing a covalent organic framework material with carbon-carbon double bonds; and then preparing the pentafluorobenzyl functional covalent organic framework material from the ionic liquid containing the pentafluorobenzyl functional group and the covalent organic framework material containing the carbon-carbon double bond by using tetrahydrofuran as a solvent and azodiisobutyronitrile as a thermal initiator through a covalent bonding method. Compared with a covalent organic framework material with carbon-carbon double bonds, the surface hydrophobicity of the pentafluorobenzyl functionalized covalent organic framework material is remarkably improved, and rich pentafluorobenzyl functional groups contained in the pentafluorobenzyl functionalized covalent organic framework material can provide hydrogen bond acting force for an analyte; the enrichment capacity of the pentafluorobenzyl functionalized covalent organic framework material on bisphenol environmental pollutants is greatly improved, and the enrichment performance is 1.5-1.8 times that of a covalent organic framework material with carbon-carbon double bonds.

Description

Technical Field

[0001] The invention relates to the technical field of material preparation, and in particular to a pentafluorobenzyl functionalized covalent organic framework material and a preparation method and application thereof. Background Art

[0002] Bisphenol compounds have the characteristics of high toxicity, persistence, bioaccumulation, and long-range migration. For humans at the top of the food chain, these toxicities are magnified more than 70,000 times than the original. The development of accurate and sensitive detection and monitoring as well as efficient removal methods for bisphenol compounds can avoid risks before they cause harm, which is of great research significance for further protecting human health. In the technology for this purpose, the adsorption performance of the adsorbent material is one of the key factors that determine whether the established method has practical application value. In order to achieve high adsorption capacity and fast kinetics, the use of complexing functional groups to combat bisphenol pollution has begun to play a role. Based on the covalent grafting of functional groups to the surfaces of porous materials such as silica gel, clay, and MOFs, many sample pretreatment materials and adsorbents have been developed. However, current adsorbents face the problem that the small and irregular pore structure of stable polymers limits the contact binding sites of pollutants and the water sensitivity of MOFs with regular pore structures limits their large-scale application. Considering these weaknesses associated with existing adsorbents, it is necessary to develop new materials that show greater potential in remediation technologies.

[0003] As a type of porous material, covalent organic frameworks (COFs) effectively circumvent the disordered pore structure of traditional inorganic porous materials and the lack of stability of classic MOFs materials, and have unique mesopore size, low density, good stability and other characteristics. COFs with the right combination of characteristics have the potential to become excellent adsorbents for environmental remediation. By controlling the bonding environment of COFs, special active sites can be introduced, and increasing the affinity for harmful organic pollutants may also help alleviate the environmental problems caused by them. Studies have shown that the introduction of electron-withdrawing fluorine substituents into aromatic molecules helps to polarize their π conjugated system and enhance π-π stacking through electrostatic interactions. The pentafluorobenzyl functional group, in which the fluorine element replaces five hydrogens on the benzene ring, has a polarized conjugated system and can form a strong π-π stacking with the benzene ring structure with two hydroxyl substitutions in the structure of bisphenol compounds. However, due to the fact that not all functional groups are compatible or stable with the synthesis conditions of COFs, functionalized COFs materials with high fluorination and unaffected crystal form are still relatively limited. Summary of the invention

[0004] The purpose of the present invention is to provide a pentafluorobenzyl functionalized covalent organic framework material and a preparation method and application thereof, so as to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is to provide a method for preparing a pentafluorobenzyl functionalized covalent organic framework material, the steps comprising:

[0007] A first reaction system including reactants, a first solvent and a first thermal initiator is established, and the pentafluorobenzyl functionalized covalent organic framework material is prepared by a covalent bonding method; wherein the reactants include a covalent organic framework material containing a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group, and the first thermal initiator is azobisisobutyronitrile (AIBN).

[0008] Furthermore, the concentration of the covalent organic framework material containing carbon-carbon double bonds in the first reaction system is 3 to 15 mM.

[0009] Furthermore, the concentration of the ionic liquid containing pentafluorobenzyl functional groups in the first reaction system is 1-5 mM.

[0010] Furthermore, the concentration of the thermal initiator in the first reaction system is 0.5-2.4 mM.

[0011] Furthermore, the ionic liquid containing a pentafluorobenzyl functional group is 1-pentafluorobenzyl-vinylimidazolium bromide (IL-5F) or 1-pentafluorobenzyl-vinylimidazolium chloride (IL-5F(Cl)).

[0012] Furthermore, the first solvent is tetrahydrofuran.

[0013] Furthermore, the preparation steps of the covalent organic framework material containing carbon-carbon double bonds include:

[0014] Establishing a second reaction system including a ligand, a second solvent, and a second thermal initiator, and preparing a covalent organic framework material having a carbon-carbon double bond by a covalent bonding method;

[0015] The ligand includes a compound containing an aldehyde functional group and a compound containing an amino functional group, the second solvent is acetonitrile (ACN), and the second thermal initiator is acetic acid.

[0016] Furthermore, the concentration of the compound containing an aldehyde functional group in the second reaction system is 6 to 30 mM.

[0017] Furthermore, the concentration of the compound containing an amino functional group in the second reaction system is 4 to 20 mM.

[0018] Furthermore, the compound containing an aldehyde functional group is 2,5-divinylterephthalaldehyde (DVA) or 2,5-bis(allyloxy)terephthalaldehyde (BTD); the compound containing an amino functional group is 1,3,5-tris(4-aminophenyl)benzene (TPB) or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TTT).

[0019] Furthermore, the volume ratio of the acetic acid to acetonitrile is 1:4-8.

[0020] The second technical solution of the present invention is to provide a pentafluorobenzyl functionalized covalent organic framework material prepared by the above preparation method.

[0021] The pentafluorobenzyl functionalized covalent organic framework material prepared by the invention is self-assembled by an IL-5F ligand containing a pentafluorobenzyl functional group, a ligand containing an aldehyde group (DVA or BTD) and a ligand containing an amino group (TPB or TTT), wherein the IL-5F ligand contains a carbon-carbon double bond and a pentafluorobenzyl functional group, the ligand containing an aldehyde group contains two aldehyde functional groups, and the ligand containing an amino group contains three amino groups. The pentafluorobenzyl functionalized covalent organic framework material has a pentafluorobenzyl functional group, and can provide additional hydrogen bonding force to a target object compared with a covalent organic framework material containing a carbon-carbon double bond, and furthermore, as a solid phase extraction coating material, the enrichment multiple of bisphenol compounds is 1.5 to 1.8 times that of the covalent organic framework material containing a carbon-carbon double bond.

[0022] The third technical solution of the present invention is to provide an application of the above-mentioned pentafluorobenzyl functionalized covalent organic framework material in enriching bisphenol compounds.

[0023] Furthermore, the bisphenol compound is preferably bisphenol.

[0024] The fourth technical solution of the present invention is to provide an application of the above-mentioned pentafluorobenzyl functionalized covalent organic framework material in the adsorption and removal of bisphenol.

[0025] The fifth technical solution of the present invention is to provide an application of the above-mentioned pentafluorobenzyl functionalized covalent organic framework material in the trace detection of bisphenol.

[0026] The pentafluorobenzyl functional group introduced by the present invention contains 5 electron-withdrawing fluorine substituents, which are helpful to polarize the π conjugated system of the aromatic molecule and enhance the π-π stacking effect between the target analyte through electrostatic interaction. The fluorine substituent contained therein can also act as a hydrogen bond donor to interact with bisphenol compounds (BPs) containing hydroxyl functional groups. Compared with the original unfunctionalized covalent organic framework material containing carbon-carbon double bonds, the pentafluorobenzyl functional group in the pentafluorobenzyl functionalized covalent organic framework material can act as a hydrogen bond donor to provide additional hydrogen bonding force for separating and enriching harmful BPs, which is beneficial to increase the sensitivity of the detection method. Due to this unique property, the functionalized COF introduced with the pentafluorobenzyl group can enrich bisphenols and realize trace detection of bisphenols.

[0027] Technical solution 6 of the present invention: Provide a method for improving the detection sensitivity of a covalent organic framework material containing a carbon-carbon double bond to bisphenol, the steps comprising:

[0028] A first reaction system including reactants, a first solvent and a first thermal initiator is established, and the pentafluorobenzyl functionalized covalent organic framework material is prepared by a covalent bonding method; wherein the reactants include a covalent organic framework material containing a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group, and the first thermal initiator is azobisisobutyronitrile.

[0029] Technical solution seven of the present invention: Provide a method for improving the efficiency of enriching bisphenol compounds in a covalent organic framework material containing carbon-carbon double bonds, the steps comprising:

[0030] A first reaction system including reactants, a first solvent and a first thermal initiator is established, and the pentafluorobenzyl functionalized covalent organic framework material is prepared by a covalent bonding method; wherein the reactants include a covalent organic framework material containing a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group, and the first thermal initiator is azobisisobutyronitrile.

[0031] Technical solution eight of the present invention: Provide a method for detecting trace amounts of BPs, comprising the following steps:

[0032] The pentafluorobenzyl functionalized covalent organic framework material was used as a solid phase extraction material to separate and enrich BPs in a complex matrix, and the BPs content was detected in conjunction with HPLC-DAD.

[0033] The pentafluorobenzyl functionalized covalent organic framework material prepared by the present invention is used as a solid phase extraction material to separate and enrich BPs in a complex matrix, and is combined with HPLC-DAD to track and detect its content to evaluate environmental safety.

[0034] The present invention discloses the following technical effects:

[0035] The pentafluorobenzyl functionalized covalent organic framework material of the present invention is first prepared from aldehyde ligands containing carbon-carbon double bonds and amino ligands to obtain a covalent organic framework material containing carbon-carbon double bonds with good crystal form and good stability, and then the covalent organic framework material containing carbon-carbon double bonds and an ionic liquid containing a pentafluorobenzyl functional group are bonded through an addition reaction. The prepared pentafluorobenzyl functionalized covalent organic framework material can enrich the environmental pollutant BPs with a high capacity, exhibits excellent reproducibility and reusability, and has a simple preparation process, low cost, and good application prospects.

[0036] The preparation process of the method of the present invention is simple and easy to operate, and does not require an anaerobic high-temperature environment and complex instruments. The prepared new pentafluorobenzyl functionalized covalent organic framework material has a high loading amount of electron-withdrawing fluorine substituents, good crystal form, high hydrophobicity, and a large specific surface area. It can enrich BPs with high capacity and has good reproducibility and repeatable practical performance, which provides the possibility for the commercial production of the material.

[0037] The pentafluorobenzyl functionalized covalent organic framework material of the present invention has good dispersibility in water and good stability (thermal stability and acid-base stability), can be reused many times, and can greatly reduce the use cost.

[0038] The present invention fully utilizes the advantages of the interaction between functional groups and analytes. The functionalized pentafluorobenzyl functional groups in the material can provide hydrogen bonding sites for the target. Covalent bonds and strategies are used under mild conditions to prepare functionalized materials with high hydrophobicity, which greatly expands the types of organic framework materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 The SEM images, transmission electron microscopy images and element mapping images of SCOF-V / IL-5F in Example 1 and the SEM image of SCOF-V in Comparative Example 1, wherein (a) to (c) are SEM images of SCOF-V / IL-5F, (d) is an SEM image of SCOF-V, (e) to (f) are transmission electron microscopy images of SCOF-V / IL-5F, and (g) to (j) are element mapping images of SCOF-V / IL-5F;

[0041] Figure 2FT-IR spectra of SCOF-V, IL-5F, and SCOF-V / IL-5F;

[0042] Figure 3 XRD patterns of SCOF-V and SCOF-V / IL-5F;

[0043] Figure 4 N of SCOF-V and SCOF-V / IL-5F 2 Adsorption temperature curve;

[0044] Figure 5 TG curves of SCOF-V and SCOF-V / IL-5F;

[0045] Figure 6 is the water contact angle of SCOF-V and SCOF-V / IL-5F, where (a) is SCOF-V, and (b) is SCOF-V / IL-5F;

[0046] Figure 7 The XRD patterns of SCOF-V / IL-5F measured after being immersed in different solvents for 24 hours;

[0047] Figure 8 This is the SEM image of the SCOF-V / IL-5F material after six cycles of use;

[0048] Fig. 9 It is a comparison chart of the enrichment performance of SCOF-V / IL-5F and SCOF-V for BPs environmental pollutants;

[0049] Fig.10 This is the chromatogram of SCOF-V / IL-5F measuring the BPs content in actual environmental water samples. DETAILED DESCRIPTION

[0050] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0051] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0052] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0053] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0054] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0055] In some specific embodiments, the present invention provides a method for preparing a pentafluorobenzyl functionalized covalent organic framework material, comprising the following steps:

[0056] S1. Dissolving a compound containing an aldehyde functional group and a compound containing an amino functional group in acetonitrile, ultrasonically treating, then adding acetic acid to obtain a mixed solution, and then standing at room temperature for reaction. After the reaction is completed, washing the obtained product, centrifuging, and drying to obtain a covalent organic framework material having a carbon-carbon double bond;

[0057] S2. Disperse a covalent organic framework material having a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group in tetrahydrofuran, perform ultrasonic treatment, then add AIBN to obtain a mixed system, and then stir in a water bath. After the reaction is completed, wash, centrifuge, and dry the obtained product to obtain a pentafluorobenzyl functionalized covalent organic framework material.

[0058] The invention discloses a novel pentafluorobenzyl functionalized covalent organic framework material (and its preparation method and application) as a separation and enrichment material. The functionalized material is prepared in two steps. First, a covalent organic framework material containing a carbon-carbon double bond is prepared by self-assembly of a ligand containing an aldehyde group and a ligand containing an amino group during standing at room temperature; acetic acid is used as a catalyst in the preparation process to promote the reaction and improve the crystal strength. Then, the covalent organic framework material containing a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group are stirred in a water bath and thermally polymerized to obtain a novel pentafluorobenzyl functionalized covalent organic framework material. The pentafluorobenzyl functionalized covalent organic framework material is prepared under mild conditions, and the process is simple and easy to Reproducibility. Compared with unfunctionalized organic framework materials (COF), the hydrophobicity of pentafluorobenzyl-functionalized organic framework materials is significantly increased, and they have unique pentafluorobenzyl functional groups. Compared with unfunctionalized COF materials, the separation and enrichment ability of pentafluorobenzyl-functionalized organic framework materials for BPs is greatly increased, and the enrichment performance is 1.5-1.8 times that of unfunctionalized organic framework materials (COF). The preparation process of the present invention is simple, and the obtained pentafluorobenzyl-functionalized organic framework material has superb separation and enrichment ability for bisphenol pollutants, and has good stability and is easy to regenerate, and can be repeatedly used, and has good application prospects in the fields of detecting bisphenol pollutants in complex environmental matrices.

[0059] In some specific embodiments, the compound containing an aldehyde functional group is 2,5-divinylterephthalaldehyde (DVA) or 2,5-bis(allyloxy)terephthalaldehyde (BTD).

[0060] In some specific embodiments, the compound containing an amino functional group is 1,3,5-tris(4-aminophenyl)benzene (TPB) or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TTT).

[0061] In some specific embodiments, the ionic liquid containing a pentafluorobenzyl functional group is 1-pentafluorobenzyl-vinylimidazolium bromide (IL-5F) or 1-pentafluorobenzyl-vinylimidazolium chloride (IL-5F(Cl)).

[0062] In some specific embodiments, the concentration of the compound containing an amino functional group in the mixed solution is 4-20 mM.

[0063] In some specific embodiments, the concentration of the compound containing an aldehyde functional group in the mixed solution is 6-30 mM.

[0064] In some specific embodiments, the volume ratio of acetic acid to acetonitrile is (1:8) to (1:4).

[0065] In some specific embodiments, the concentration of the covalent organic framework material having a carbon-carbon double bond in the mixed system is 3 to 15 mM.

[0066] In some specific embodiments, the concentration of the ionic liquid containing pentafluorobenzyl functional groups in the mixed system is 1-5 mM.

[0067] In some specific embodiments, the concentration of AIBN in the mixed system is 0.5-2.4 mM.

[0068] In some specific embodiments, the ultrasonic treatment time in step S2 is 5 to 20 minutes, the water bath temperature is 50 to 80° C., the stirring time is 12 to 24 hours, and the drying is vacuum drying at 60° C. for 24 hours.

[0069] The present invention synthesizes a novel pentafluorobenzyl functionalized covalent organic framework material under mild water bath conditions, and is applied to environmental bisphenol compounds as a separation and enrichment material, and is used in conjunction with a high performance liquid chromatography-diode array detector (HPLC-DAD) to detect trace BPs in a complex matrix environment for tracking detection to evaluate environmental safety. As an adsorption and enrichment material, the pentafluorobenzyl functionalized covalent organic framework material inherits the excellent properties of COFs materials and adds functional groups, has high hydrophobicity, high surface area-volume ratio, good dispersibility, good structural stability, thermal stability, easy preparation and other advantages, and at the same time, the introduction of pentafluorobenzyl functional groups and enhanced hydrophobicity increase the affinity of the material to the target, which is conducive to improving the enrichment and adsorption performance. The preparation process is simple, easy to operate, does not require an anaerobic high temperature environment and complex instruments, and the prepared material has a high F content and crystallinity.

[0070] The raw materials and reagents used in the specific implementation scheme of the present invention are all commercially available products, among which TPB, BTD, TTT and DVA are provided by Jilin Yanshen Technology Co., Ltd.; IL-5F and IL-5F(Cl) are provided by Shanghai Chengjie Chemical Co., Ltd.; CAN is provided by Tiandi Co., Ltd. of the United States.

[0071] Example 1

[0072] The preparation steps of pentafluorobenzyl functionalized covalent organic framework materials are as follows:

[0073] S1, TPB (0.04 mmol) and DVA (0.06 mmol) were dissolved in 5 mL of acetonitrile solution, ultrasonically treated for 1 min, 1.0 mL of acetic acid solution (12 M) was added to the above solution, and then allowed to stand at room temperature for 24 h. After the reaction was completed, the reaction product was washed alternately with acetonitrile and ethanol for 3 times, centrifuged at a speed of 10000 rpm for 2 min, and the solid product was vacuum dried at 60 ° C for 24 h to obtain SCOF-V;

[0074] S2. Dissolve SCOF-V (0.15 mmol) and IL-5F (0.451 mmol) in 58 mL of tetrahydrofuran solution, ultrasonically treat for 10 min, add AIBN (0.0719 mmol) to the above solution, ultrasonically treat for 5 min, and then stir at 60 ° C for 20 h. After the reaction is completed, wash the reaction product with ethanol 6 times, centrifuge at 10000 rpm for 2 min, and vacuum dry the solid product at 60 ° C for 24 h to obtain a pentafluorobenzyl functionalized covalent organic framework material, recorded as SCOF-V / IL-5F.

[0075] Example 2

[0076] The preparation steps of pentafluorobenzyl functionalized covalent organic framework materials are as follows:

[0077] S1. Dissolve TTT (0.04 mmol) and BTD (0.06 mmol) in 5 mL of acetonitrile solution, perform ultrasonic treatment for 1 min, add 1.0 mL of acetic acid solution (12 M) to the above solution, and then stand at room temperature for 24 h. After the reaction is completed, wash the reaction product with acetonitrile and ethanol alternately for 3 times, centrifuge at 10000 rpm for 2 min, and dry the solid product in vacuum at 60 ° C for 24 h to obtain SCOF-T;

[0078] S2. Dissolve SCOF-T (0.15 mmol) and IL-5F (Cl) (0.451 mmol) in 58 mL of tetrahydrofuran solution, ultrasonically treat for 10 min, add AIBN (0.0719 mmol) to the above solution, ultrasonically treat for 5 min, and then stir at 60 ° C for 20 h. After the reaction is completed, wash the reaction product with ethanol 6 times, centrifuge at 10000 rpm for 2 min, and vacuum dry the solid product at 60 ° C for 24 h to obtain a pentafluorobenzyl functionalized covalent organic framework material, recorded as SCOF-T / IL-5F (Cl).

[0079] Example 3

[0080] The preparation steps of pentafluorobenzyl functionalized covalent organic framework materials are as follows:

[0081] S1, TPB (0.04 mmol) and BTD (0.06 mmol) were dissolved in 5 mL of acetonitrile solution, ultrasonically treated for 1 min, 1.0 mL of acetic acid solution (12 M) was added to the above solution, and then allowed to stand at room temperature for 24 h. After the reaction was completed, the reaction product was washed alternately with acetonitrile and ethanol for 3 times, centrifuged at a speed of 10000 rpm for 2 min, and the solid product was vacuum dried at 60 ° C for 24 h to obtain SCOF-B;

[0082] S2. Dissolve SCOF-B (0.15 mmol) and IL-5F (0.451 mmol) in 58 mL of tetrahydrofuran solution, ultrasonically treat for 10 min, add AIBN (0.0719 mmol) to the above solution, ultrasonically treat for 5 min, and then stir at 60 ° C for 20 h. After the reaction is completed, wash the reaction product with ethanol 6 times, centrifuge at 10000 rpm for 2 min, and vacuum dry the solid product at 60 ° C for 24 h to obtain a pentafluorobenzyl functionalized covalent organic framework material, recorded as SCOF-B / IL-5F.

[0083] Example 4

[0084] The preparation steps of pentafluorobenzyl functionalized covalent organic framework materials are as follows:

[0085] S1. Dissolve TTT (0.04 mmol) and DVA (0.06 mmol) in 5 mL of acetonitrile solution, perform ultrasonic treatment for 1 min, add 1.0 mL of acetic acid solution (12 M) to the above solution, and then stand at room temperature for 24 h. After the reaction is completed, wash the reaction product with acetonitrile and ethanol alternately for 3 times, centrifuge at 10000 rpm for 2 min, and dry the solid product in vacuum at 60 ° C for 24 h to obtain SCOF-TT;

[0086] S2. Dissolve SCOF-TT (0.15 mmol) and IL-5F (0.451 mmol) in 58 mL of tetrahydrofuran solution, ultrasonically treat for 10 min, add AIBN (0.0719 mmol) to the above solution, ultrasonically treat for 5 min, and then stir at 60 ° C for 20 h. After the reaction is completed, wash the reaction product with ethanol 6 times, centrifuge at 10000 rpm for 2 min, and vacuum dry the solid product at 60 ° C for 24 h to obtain a pentafluorobenzyl functionalized covalent organic framework material, recorded as SCOF-TT / IL-5F.

[0087] Comparative Example 1

[0088] The preparation steps of SCOF-V are:

[0089] TPB (0.04 mmol) and DVA (0.06 mmol) were dissolved in 5 mL of acetonitrile solution, ultrasonically treated for 1 min, 1.0 mL of acetic acid solution (12 M) was added to the above solution, and then allowed to stand at room temperature for 24 h. After the reaction was completed, the reaction product was washed alternately with acetonitrile and ethanol for 3 times, centrifuged at 10000 rpm for 2 min, and the solid product was vacuum dried at 60 ° C for 24 h to obtain SCOF-V.

[0090] Comparative Example 2

[0091] The preparation steps of SCOF-T are:

[0092] TTT (0.04 mmol) and BTD (0.06 mmol) were dissolved in 5 mL of acetonitrile solution, ultrasonically treated for 1 min, 1.0 mL of acetic acid solution (12 M) was added to the above solution, and then allowed to stand at room temperature for 24 h. After the reaction was completed, the reaction product was washed alternately with acetonitrile and ethanol for 3 times, centrifuged at 10000 rpm for 2 min, and the solid product was vacuum dried at 60 ° C for 24 h to obtain SCOF-T.

[0093] Test example

[0094] Figure 1 The SEM images, transmission electron microscope images and element mapping images of SCOF-V / IL-5F in Example 1 and the SEM image of SCOF-V in Comparative Example 1 are, among which, (a) to (c) are SEM images of SCOF-V / IL-5F, (d) is the SEM image of SCOF-V, (e) to (f) are transmission electron microscope images of SCOF-V / IL-5F, and (g) to (j) are element mapping images of SCOF-V / IL-5F.

[0095] Figure 2 FT-IR spectra of SCOF-V, IL-5F, and SCOF-V / IL-5F; Figure 3 XRD patterns of SCOF-V and SCOF-V / IL-5F; Figure 4 N of SCOF-V and SCOF-V / IL-5F 2 Adsorption temperature curve; Figure 5 TG curves of SCOF-V and SCOF-V / IL-5F; Figure 6 is the water contact angle of SCOF-V and SCOF-V / IL-5F, where (a) is SCOF-V and (b) is SCOF-V / IL-5F. Figures 2 to 6 It can be seen that after functionalization of the SCOF-V material, it maintains a high degree of crystallinity ( Figure 3 ), the loading amount of IL-5F contained in SCOF-V / IL-5F was 4.2%, indicating that the prepared material had a high F element loading amount ( Figure 5 ), compared with SCOF-V material, the functionalized SCOF-V / IL-5F has an enhanced water contact angle, indicating that it has higher hydrophobic properties ( Figure 6 ).

[0096] The enrichment performance of SCOF-V / IL-5F prepared in Example 1 and SCOF-V prepared in Comparative Example 1 for BPs was compared to verify the effect of the functionalized functional group (pentafluorobenzyl group) on improving the adsorption performance of the material and the adsorption capacity of the product obtained by the present invention for BPs, and the method is as follows:

[0097] The SCOF-V / IL-5F prepared in Example 1 and the SCOF-V prepared in Comparative Example 1 were dispersed as adsorbents in a mixture containing a mixed standard solution (bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB), bisphenol AF (BPAF)) (30 mL, 200 ng mL -1 ) in a centrifuge tube, and the centrifuge tube was placed in an ultrasonic machine with a power of 60 W and a temperature of room temperature for extraction. After the extraction was balanced, the SCOF-V / IL-5F complex and the SCOF-V complex were collected under centrifugation into centrifuge tubes containing acetonitrile, and after ultrasonic treatment, the eluate was collected and 2 Finally, the residue was reconstituted in 100 μL acetonitrile, filtered through a 0.22 μm nylon membrane and subjected to HPLC-DAD analysis.

[0098] Figure 7 The XRD patterns of SCOF-V / IL-5F were measured after being immersed in different solvents for 24 hours. Figure 7 It can be seen that the peak position and peak shape of the XRD diffraction pattern of SCOF-V / IL-5F measured after immersion in different solutions for 24 h did not change, indicating that the material has high stability.

[0099] Figure 8 This is the SEM image of the SCOF-V / IL-5F material after six cycles of use. Figure 8 It can be seen that after 6 consecutive adsorption-desorption cycles, the morphology of the material did not change, which once again proved the stability of the material.

[0100] Fig. 9 The comparison of the enrichment performance of SCOF-V / IL-5F and SCOF-V for BPs environmental pollutants is shown in Figure 2. Fig. 9 It can be seen that the adsorption amounts of SCOF-V / IL-5F for BPAF, BPA, BPB and BPF are 1.5, 1.7, 1.5 and 1.8 times that of SCOF-V, respectively. It can be seen that compared with SCOF-V, SCOF-V / IL-5F exhibits better separation and enrichment performance for BPs environmental pollutants, indicating that functional groups have great potential in increasing the adsorption performance of materials.

[0101] SCOF-V / IL-5F was used as an adsorbent in combination with HPLC-DAD to detect the content of BPs in environmental water samples and verify the anti-interference ability of SCOF-V / IL-5F. The method is as follows:

[0102] Water samples were collected from Tieta Lake and filtered through a 0.22 μm nylon membrane to remove possible suspended particles. After filtration, the water samples were stored in pre-cleaned glass bottles at 4 °C for analysis by HPLC-DAD during the extraction process. The analysis results are shown in Fig.10 The specific conditions of the detection were as follows: BPs were separated using a ZORBAX SB-C18 column (4.6 mm × 150 mm, id, 5 μm), and BPs were analyzed and detected using an Agilent 1260 HPLC-DAD (Agilent Technologies, Santa Clara, CA); a mixture of acetonitrile (A) and water (B) was used as the mobile phase (0-4 min, 50-70% A; 4-8 min, 70-50% A), with a flow rate of 0.5 mL min -1 , the column temperature was maintained at 25°C. The detection wavelength of the detector was 229 nm, and the injection volume was 5.0 μL.

[0103] Fig.10 This is the chromatogram of SCOF-V / IL-5F for the determination of BPs content in actual environmental water samples. Fig.10 It can be seen that BPF (2.46 ng mL -1 )Target( Fig.10 The black line in the middle shows that the SCOF-V / IL-5F prepared by the present invention has good analytical performance for trace targets. Then, the water samples were spiked (targets (bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB), bisphenol AF (BPAF)) were added to the water samples before treatment to prepare 10, 70, and 400 ng mL -1 The sample solution is processed, enriched and detected (as shown by the red line in the figure), where chromatographic peak 1 is bisphenol F (BPF), chromatographic peak 2 is bisphenol A (BPA), chromatographic peak 3 is bisphenol B (BPB), and chromatographic peak 4 is bisphenol AF (BPAF); this indicates that the established method exhibits high recovery (82.3% to 97.9%) and good reproducibility (RSD, 1.5 to 10.6%) for BPs in environmental water samples. It can be seen from the experimental results that this method has great potential in detecting trace amounts of BPs in complex actual samples. At the same time, Fig.10 The symmetrical chromatographic peaks in the results indicate that the established method is not affected by complex environmental water matrices, and has strong anti-interference ability and good selectivity for complex environmental water sample matrices.

[0104] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a pentafluorobenzyl functionalized covalent organic framework material, characterized in that the steps include: A first reaction system including reactants, a first solvent and a first thermal initiator is established, and the pentafluorobenzyl functionalized covalent organic framework material is prepared by a covalent bonding method; wherein the reactants include a covalent organic framework material containing a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group, and the first thermal initiator is azobisisobutyronitrile.

2. The preparation method according to claim 1, characterized in that The concentration of the covalent organic framework material containing carbon-carbon double bonds in the first reaction system is 3 to 15 mM; the concentration of the ionic liquid containing pentafluorobenzyl functional groups in the first reaction system is 1 to 5 mM; the concentration of the first thermal initiator in the first reaction system is 0.5 to 2.4 mM; the ionic liquid containing pentafluorobenzyl functional groups is 1-pentafluorobenzyl-vinyl imidazolium bromide or 1-pentafluorobenzyl-vinyl imidazolium chloride; and the first solvent is tetrahydrofuran.

3. The preparation method according to claim 1, characterized in that: The steps of preparing the covalent organic framework material containing carbon-carbon double bonds include: Establishing a second reaction system including a ligand, a second solvent, and a second thermal initiator, and preparing a covalent organic framework material having a carbon-carbon double bond by a covalent bonding method; The ligand includes a compound containing an aldehyde functional group and a compound containing an amino functional group, the second solvent is acetonitrile, and the second thermal initiator is acetic acid; The concentration of the compound containing aldehyde functional groups in the second reaction system is 6 to 30 mM; the concentration of the compound containing amino functional groups in the second reaction system is 4 to 20 mM; the compound containing aldehyde functional groups is 2,5-divinylterephthalaldehyde or 2,5-bis(allyloxy)terephthalaldehyde; the compound containing amino functional groups is 1,3,5-tris(4-aminophenyl)benzene or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine; the volume ratio of acetic acid to acetonitrile is 1:4 to 8.

4. A pentafluorobenzyl functionalized covalent organic framework material prepared by the preparation method according to any one of claims 1 to 3.

5. Use of the pentafluorobenzyl functionalized covalent organic framework material as claimed in claim 4 in enriching bisphenol compounds.

6. Use of the pentafluorobenzyl functionalized covalent organic framework material as claimed in claim 4 in the adsorption and removal of bisphenol.

7. Use of the pentafluorobenzyl functionalized covalent organic framework material as claimed in claim 4 in trace detection of bisphenol.

8. A method for improving the detection sensitivity of a covalent organic framework material containing carbon-carbon double bonds to bisphenol, characterized in that the steps include: A first reaction system including reactants, a first solvent and a first thermal initiator is established, and the pentafluorobenzyl functionalized covalent organic framework material is prepared by a covalent bonding method; wherein the reactants include a covalent organic framework material containing a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group, and the first thermal initiator is azobisisobutyronitrile.

9. A method for improving the efficiency of enriching bisphenol compounds in a covalent organic framework material containing carbon-carbon double bonds, comprising: A first reaction system including reactants, a first solvent and a first thermal initiator is established, and the pentafluorobenzyl functionalized covalent organic framework material is prepared by a covalent bonding method; wherein the reactants include a covalent organic framework material containing a carbon-carbon double bond and an ionic liquid containing a pentafluorobenzyl functional group, and the first thermal initiator is azobisisobutyronitrile.

10. A method for detecting trace amounts of BPs, characterized in that the steps include: The pentafluorobenzyl functionalized covalent organic framework material according to claim 4 is used as a solid phase extraction material to separate and enrich BPs in a complex matrix, and the BPs content is detected in conjunction with HPLC-DAD.

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