A kind of amidoxime material and its preparation method and application

Abstract

The application discloses a kind of amidoxime materials and its preparation method and application, belong to heavy metal adsorption material field.Amidoxime material in the application is prepared by Schiff base reaction, addition reaction and metal loading, catalyst and regulator need to be added in the process of Schiff base reaction to form specific morphology in preparation process, and monomer in the process of addition reaction also needs to have cyano and mercapto simultaneously, to provide fixed basis for subsequent metal loading process and respond to heavy metal to be adsorbed.Amidoxime group in the amidoxime material in the application has strong multidentate coordination ability, can adsorb heavy metal ions, and reducing agent used in the process of metal loading can reduce heavy metal ions, so that the amidoxime material has adsorption and reduction performance simultaneously.

Description

Technical Field

[0001] This invention relates to the field of heavy metal adsorption materials, specifically to a amine oxime material, its preparation method, and its application. Background Technology

[0002] Covalent organic frameworks (COFs) are a class of crystalline porous materials formed by the self-assembly of lightweight elements through high-strength covalent bonds. Their core characteristics lie in their highly ordered periodic pore structure and precisely controllable topological network, aided by pre-designable monomer precursors during synthesis. They have already demonstrated disruptive application potential in fields such as gas storage, molecular separation, catalyst supports, and radionuclide capture. In the field of nuclear waste treatment, traditional adsorbents such as activated carbon and zeolites are insufficient to meet the demands of high-level radioactive waste treatment due to their limited specific surface area, low adsorption capacity, and poor radiation resistance. Covalent organic framework materials, with their highly ordered crystalline porous structure and functionalizable framework, have become disruptive materials for the efficient separation of radionuclides.

[0003] CN116253848A discloses a covalent organic framework, its synthesis method, and its application in the field of uranium adsorption. This invention is based on the 2,3-dihydroxy functional group, which has a strong adsorption effect on uranyl ions. Using 2,3-dihydroxyterephthalaldehyde as a two-linked building block, it reacts with three-linked or six-linked building blocks with heteroatoms (N, B, P) to obtain two kinds of porous organic frameworks.

[0004] CN118702884A discloses a method for preparing a heteroporous metal covalent organic framework and its application, belonging to the field of environmental protection technology. This invention first obtains a copper metal single crystal by co-culturing 2,2'-bipyridine-5,5'-diamine with CuCl2•2H2O. Then, the copper metal single crystal, [1,1':3',1''-terphenyl]-3,3'',5,5''-tetraaldehyde, and p-diaminobiphenyl are reacted via a Schiff base reaction to prepare a heteroporous metal covalent organic framework.

[0005] Existing covalent organic framework materials have shown preliminary effects on uranium adsorption. However, the synthesis process of the adsorbent materials in the existing methods is still relatively complex and costly. Furthermore, the adsorption efficiency is low, the adsorption capacity is limited, and the stability, long-term adsorption rate and selectivity of the adsorbent materials are weak. They are also affected by acid and alkaline environments, which are all problems that need to be solved. Summary of the Invention

[0006] To address the above problems, this invention provides a metallo-oxime material, its preparation method, and its application. The material with metallo-oxime groups as described in this invention is prepared by using raw materials with specific structures under specific conditions and proportions. The metallo-oxime material has a stable flower-like structure, and the covalent organic framework structure also improves its long-term stability and chemical resistance as a catalyst or adsorbent.

[0007] This invention provides a methylamine oxime material, wherein the methylamine oxime material comprises 6n atoms 6n and 12n Where n is a positive integer greater than or equal to 1, and M is Fe 2+ Co 2+ Ni 2+ Cu 2+ Zn 2+ Sn 2+ Pt 2+ Pb 2+ Ra 2+ Ag + and Au 3+ One or more of them;

[0008] The raw materials for preparing the amylopyridine material include amino monomers with three amino groups (-NH2) and aldehyde monomers with two aldehyde groups (-CHO), as well as cyano monomers with cyano groups (-C≡N) and metal ion monomers, as well as carbonate monomers and amylopyridine materials.

[0009] Further, the amino monomer and the aldehyde monomer undergo a Schiff base reaction, the cyano monomer undergoes an addition reaction with the product of the reaction between the amino monomer and the aldehyde monomer, the metal ion monomer loads the product of the reaction between the amino monomer and the aldehyde monomer after the addition of the cyano monomer, and then the cyano group in the cyano monomer is converted into a metallo-oxime group by the carbonate monomer and the oxime material to obtain the metallo-oxime material.

[0010] Furthermore, the methine oxime material has a flower-like structure, and the specific surface area (BET value) of the methine oxime material is 540-610 m². 2 / g, pore volume is 0.70-0.76cm³ 3 / g, with an average pore size of 3.30-3.60nm; after soaking under acidic conditions, soaking under alkaline conditions, and placing at a high temperature of 200℃, the specific surface area, pore volume, and pore size remain unchanged.

[0011] Furthermore, the Schiff base reaction process also includes a catalyst and a regulator.

[0012] Furthermore, the catalyst is acetic acid.

[0013] Furthermore, the regulator is aniline.

[0014] Furthermore, the addition reaction process also includes an initiator.

[0015] Furthermore, the initiator is azobisisobutyronitrile.

[0016] Furthermore, the loading process also includes a reducing agent.

[0017] Furthermore, the reducing agent is sodium borohydride.

[0018] Furthermore, the amino monomer is 1,3,5-tris(4-aminophenyl)benzene.

[0019] Furthermore, the aldehyde monomer is 2,5-divinyl-1,4-phenylenedialdehyde.

[0020] Furthermore, the cyano monomer is disodium dimercaptomalenitrogen.

[0021] Furthermore, the metal ion monomer includes one or more of the following metals: iron, cobalt, nickel, copper, zinc, tin, platinum, palladium, radium, silver, and gold.

[0022] Furthermore, the carbonate monomer is sodium carbonate.

[0023] Furthermore, the oximeting material is hydroxylamine hydrochloride.

[0024] The present invention also provides a method for preparing the aforementioned amine oxime material, comprising the following steps:

[0025] Step 1: The amino monomer and aldehyde monomer are heated and dispersed under the action of a catalyst and a regulator to react. After the reaction is completed, the obtained solid is centrifuged, washed and dried to obtain the Schiff base reaction precursor.

[0026] Step 2: The Schiff base reaction precursor and cyano monomer are heated and dispersed under the action of an initiator to react. After the reaction is completed, the obtained solid is centrifuged, washed and dried to obtain a cyano addition covalent organic framework support.

[0027] Step 3: After the cyano addition covalent organic framework carrier and the metal ion monomer undergo a light-protected reaction, a reducing agent is added to continue the reduction reaction under light-protected conditions. After the reaction is completed, the obtained solid is centrifuged, washed, and dried to obtain the metal-supported covalent organic framework material.

[0028] Step 4: Add the metal-supported covalent organic framework material to the carbonate monomer and the amine oxime material and stir to convert the cyano group. After the reaction is complete, centrifuge the obtained solid, wash and dry it to obtain the amine oxime material.

[0029] Further, in step 1, the molar ratio of the amino monomer and the aldehyde monomer is (3:2)-(2:3).

[0030] Further, the volume ratio of the catalyst and the regulator in step 1 is (12:1)-(13:1).

[0031] Further, the solvent used for heating and dispersing in step 1 is acetonitrile, and the volume ratio of acetonitrile to the catalyst is (15:1)-(17:1).

[0032] Furthermore, the mass-to-volume ratio of the amino monomer to the solvent is (14-15 mg): 5 mL.

[0033] Furthermore, the heating and dispersion temperature in step 1 is 30-40℃.

[0034] Furthermore, the heating and dispersion method in step 1 involves first stirring the amino monomer and the aldehyde monomer in a solvent, and then adding the catalyst and the regulator to react ultrasonically.

[0035] Furthermore, the stirring speed is 300-400 rpm, the stirring time is 10-20 min, the ultrasonic time is 5-10 min, and the reaction time is 72-75 h.

[0036] Furthermore, in step 1, the centrifugation speed is 8000-10000 rpm, and the centrifugation time is 5-10 min.

[0037] Furthermore, the solvents used for washing in step 1 are tetrahydrofuran and ethanol, and the washing method is to wash 3-5 times respectively.

[0038] Furthermore, in step 1, the drying temperature is 60-80℃, the drying vacuum degree is -0.1 to 0.08MPa, and the drying time is 12-24h.

[0039] Further, the amino monomer in step 1 is 1,3,5-tris(4-aminophenyl)benzene.

[0040] Further, the aldehyde monomer in step 1 is 2,5-divinyl-1,4-phenylenedialdehyde.

[0041] Furthermore, the catalyst in step 1 is one or both of acetic acid or scandium trifluoromethanesulfonate.

[0042] Furthermore, the regulator in step 1 is aniline.

[0043] Further, in step 2, the mass ratio of the Schiff base reaction precursor, the cyano monomer, and the initiator is (0.1-0.12):(0.13-0.15):(0.012-0.015).

[0044] Further, the solvent used for heating and dispersing in step 2 is N,N-dimethylformamide, and the volume-to-mass ratio of N,N-dimethylformamide to the Schiff base reaction precursor is (10-12 mL): (0.1-0.12 g).

[0045] Furthermore, the heating and dispersion temperature in step 2 is 80-100℃.

[0046] Furthermore, the stirring speed during heating and dispersion in step 2 is 300-400 rpm.

[0047] Furthermore, the reaction time in step 2 is 2-2.5 days, and the reaction condition is a nitrogen atmosphere.

[0048] Furthermore, in step 2, the centrifugation speed is 8000-10000 rpm, and the centrifugation time is 5-10 min.

[0049] Furthermore, the solvents used for washing in step 2 are acetone and ethanol, and the washing method is to wash 3-5 times respectively.

[0050] Furthermore, in step 2, the drying temperature is 60-80℃, the drying vacuum degree is -0.1 to 0.08MPa, and the drying time is 12-24h.

[0051] Furthermore, the cyano monomer in step 2 is disodium dimercaptomalenitrogen.

[0052] Furthermore, the initiator in step 2 is azobisisobutyronitrile.

[0053] Further, in step 3, the mass-to-volume ratio of the cyano addition covalent organic framework carrier, the metal ion monomer, and the reducing agent is (0.1-0.12g):(3-4mL):(15-17mL).

[0054] Furthermore, the solvent used in the light-protected reaction process in step 3 is tetrahydrofuran, and the volume-to-mass ratio of tetrahydrofuran to the cyano addition covalent organic framework support is (51-53 mL): (0.1-0.12 g).

[0055] Furthermore, the reaction in step 3 involves oscillation during the light-avoidance process, with an oscillation frequency of 55-60 times / min and an oscillation time of 2-3 hours.

[0056] Furthermore, in step 3, the reduction reaction is carried out by oscillation, the oscillation frequency is 55-60 times / min, and the oscillation time is 2-4 hours.

[0057] Furthermore, in step 3, the centrifugation speed is 8000-10000 rpm, and the centrifugation time is 5-10 min.

[0058] Furthermore, in step 3, the solvents used for washing are acetone and ethanol, and the washing method involves washing 3-5 times respectively.

[0059] Furthermore, in step 3, the drying temperature is 60-80℃, the drying vacuum degree is -0.1 to 0.08MPa, and the drying time is 12-24h.

[0060] Furthermore, the metal in the metal ion monomer in step 3 is one or more of iron, cobalt, nickel, copper, zinc, tin, platinum, palladium, radium, silver, and gold.

[0061] Furthermore, in step 3, the reducing agent is sodium borohydride with a concentration of 13-14 mg / L, and the solvent is tetrahydrofuran.

[0062] Further, in step 4, the mass ratio of the metal-supported covalent organic framework material, the carbonate monomer, and the amine oxime material is (0.1-0.2):(0.1-0.3):(0.1-0.3).

[0063] Furthermore, the solvent used in the conversion process in step 4 is deionized water and ethanol in a mass ratio of 1:2.

[0064] Furthermore, the mass ratio of the solvent to the metal-supported covalent organic framework material is 30:(0.1-0.2).

[0065] Furthermore, the stirring speed in step 4 is 300-500 rpm, and the conversion time is 7-10 h.

[0066] Furthermore, in step 4, the centrifugation speed is 8000-10000 rpm, and the centrifugation time is 5-10 min.

[0067] Furthermore, in step 4, the washing solvent is acetone and deionized water, and the washing method is to wash 3-5 times respectively.

[0068] Furthermore, in step 4, the drying temperature is 60-80℃, the drying vacuum degree is -0.1 to 0.08MPa, and the drying time is 12-24h.

[0069] Furthermore, the carbonate monomer in step 4 is sodium carbonate.

[0070] Furthermore, the oximeting material in step 4 is hydroxylamine hydrochloride.

[0071] Furthermore, the cyano addition covalent organic framework support in step 2, the metal-loaded covalent organic framework material in step 3, and the amine oxime material in step 4 all exhibit (100) and (200) crystal planes corresponding to the covalent organic framework (COF) at 2.79° and 5.58° in X-ray diffraction tests;

[0072] The metal-loaded covalent organic framework material in step 3 and the amylopyroxime material in step 4 have a (111) crystal plane of metallic gold at 38.23°, but the peak is not obvious due to the low loading of gold.

[0073] Furthermore, in the infrared spectroscopy tests of the cyano-addition covalent organic framework support in step 2, the metal-supported covalent organic framework material in step 3, and the amine oxime material in step 4, the cyano-addition covalent organic framework support and the metal-supported covalent organic framework material show a value of 2250 ± 0.01 cm⁻¹. -1 A stretching vibration peak of -CN appears at [location missing], while the peak of the thiol group (-SH) is not obvious due to being blocked. In the aforementioned amylopyridine oxime material, the cyano group is converted to [value missing] at 1620±0.01 cm⁻¹. -1 The stretching vibration peaks of -C=N and -OH at the position prove that the cyano group has been converted into a amine oxime group.

[0074] The present invention also provides a heavy metal uranium adsorbent, wherein the heavy metal uranium adsorbent is the amylopectin material.

[0075] Furthermore, the adsorption-reduction rate of the heavy metal uranium adsorbent during the adsorption-reduction process of uranium-containing wastewater is ≥97%, the adsorption-reduction rate within 10 minutes is ≥90%, the adsorption-reduction rate after 5 reuses is ≥95%, and the adsorption-reduction rate after the sixth reuse is ≥87%.

[0076] The beneficial effects of this invention are:

[0077] In addition to the Schiff base reaction between amino and aldehyde monomers, the metallo-oxime material of this invention also uses a specific aniline as a modifier to prepare a specific material with a flower-like structure. This is a technical effect that has not been achieved in existing solutions. The flower-like structure can significantly increase the specific surface area of ​​the material. On this basis, it is further added to a cyano monomer. The cyano monomer contains cyano and mercapto groups. The mercapto group can fix the metal ions in the next process. After conversion, the cyano group becomes a metallo-oxime group, which has high responsiveness to uranium, low adsorption limit, and good selectivity. The loaded metal also improves the reduction rate of uranium.

[0078] In the process of loading metals in this invention, different metals can be loaded as needed, and all of them can improve the active sites of the material in the same way, because the loading process does not change the morphology of the material. At the same time, the amylopectin material in this invention has a high adsorption rate and fast response when used as an adsorbent for uranium. Attached Figure Description

[0079] Figure 1 This is a scanning electron microscope image of the Schiff base reaction precursor described in Example 1.

[0080] Figure 2 This is a transmission electron microscope (TEM) image of the amine oxime material described in Example 1.

[0081] Figure 3 This is a magnified transmission electron microscope image of the amine oxime material described in Example 1.

[0082] Figure 4 This is the X-ray diffraction pattern of the material in Example 1.

[0083] Figure 5 The infrared spectrum of the material in Example 1 is shown below.

[0084] Figure 6 This is a reduction rate test graph of the amine oxime material described in Example 1;

[0085] Figure 7 This is a diagram showing the specific surface area of ​​materials at different stages in Example 1.

[0086] Figure 8 This is a scanning electron microscope image of the material described in Comparative Example 1;

[0087] Figure 9 This is a magnified scanning electron microscope image of the material described in Comparative Example 1. Detailed Implementation

[0088] The invention will be described in detail below with reference to the embodiments:

[0089] This invention provides a metallo-oxime material, its preparation method, and its application. The material with metallo-oxime groups is prepared by using raw materials with specific structures under specific conditions and proportions. The metallo-oxime material has a stable flower-like structure, and the covalent organic framework structure also improves its long-term stability and chemical resistance as a catalyst or adsorbent.

[0090] Example 1

[0091] This embodiment provides a methylamine oxime material, wherein the methylamine oxime material comprises 6n atoms. 6n and 12n , where n is a positive integer greater than or equal to 1;

[0092] Specifically, the structure of the amine oxime material described in this embodiment is as follows: ;

[0093] The raw materials for preparing the amylopyroxime material include an amino monomer with three amino groups (-NH2) and an aldehyde monomer with two aldehyde groups (-CHO), as well as a cyano monomer with a cyano group (-C≡N) and a metal ion monomer, as well as a carbonate monomer and an amylopyroxime material.

[0094] In this process, the amino monomer and the aldehyde monomer undergo a Schiff base reaction, the cyano monomer undergoes an addition reaction with the product of the reaction between the amino monomer and the aldehyde monomer, the metal ion monomer loads the product of the reaction between the amino monomer and the aldehyde monomer after the addition of the cyano monomer, and then the cyano group in the cyano monomer is converted into a methylamine oxime group by the carbonate monomer and the amine oxime material to obtain the methylamine oxime material;

[0095] The metallo-amino oxime material has a flower-like structure, and its specific surface area (BET value) is 571 m². 2 / g, pore volume is 0.73cm³ 3 / g, with an average pore size of 3.35nm; after soaking under acidic conditions, soaking under alkaline conditions, and placing at a high temperature of 200℃, the specific surface area, pore volume, and pore size remained unchanged.

[0096] This embodiment also provides a method for preparing the aforementioned amine oxime material, comprising the following steps:

[0097] Step 1: 14.16 mg (0.04 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 11.12 mg (0.06 mmol) of 2,5-divinyl-1,4-phenylenedialdehyde were dispersed in 5 mL of acetonitrile by stirring at 300 rpm for 20 min. 0.3 mL of acetic acid and 0.024 mL of aniline were added, and the mixture was sonicated for 5 min. The temperature was then raised to 30 °C and reacted for 72 h. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with tetrahydrofuran and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the Schiff base reaction precursor.

[0098] Step 2: 0.12 g of the Schiff base reaction precursor, 0.14 g of disodium dimercaptomalenitrogenate and 0.015 g of azobisisobutyronitrile were dispersed in 10 mL of N,N-dimethylformamide at 300 rpm. The mixture was then placed under a nitrogen atmosphere and heated to 80 °C for 2 days. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with acetone and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the cyano addition covalent organic framework support.

[0099] Step 3: Disperse 0.1g of the cyano addition covalent organic framework support and 3.75mL of 0.1wt% tetrachloroauric acid solution in 52.5mL of tetrahydrofuran and mechanically shake at 60 times / min for 3h in the dark. Then add 15mL of 13.3mg / L sodium borohydride solution (solvent is tetrahydrofuran) and continue to mechanically shake at 60 times / min for 3h in the dark for reduction reaction. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and ethanol respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the metal-supported covalent organic framework material.

[0100] Step 4: Add 0.1g of the metal-supported covalent organic framework material to 0.2g of sodium carbonate and 0.2g of hydroxylamine hydrochloride, dissolve in 10g of deionized water and 20g of ethanol at 300rpm, and stir for 7h to convert the cyano group. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and deionized water respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the metamine oxime material.

[0101] In this embodiment, the dehydration condensation of 1,3,5-tris(4-aminophenyl)benzene and 2,5-divinyl-1,4-phenylenedialdehyde yields a Schiff base reaction precursor. This precursor undergoes addition with disodium dimercaptomalenitrogenate, resulting in a cyano-addition covalent organic framework carrier containing both cyano and mercapto groups. During metal loading, the mercapto groups immobilize the metal, and under the action of a reducing agent, the metal ions are reduced to zero-valent or low-valent metals, thereby accelerating electron transfer. Finally, sodium carbonate and hydroxylamine hydrochloride are used to convert the cyano groups in the metal-loaded covalent organic framework material into a meramine oxime group. The meramine oxime group has a high response to uranium ions and can anchor and adsorb uranyl ions during adsorption. Subsequently, the reducing agent in the meramine oxime material reduces the uranyl ions, and the metallic gold accelerates electron transfer, achieving a rapid, efficient, and high-reduction-rate adsorption-reduction process. The reduced uranyl ions become uranium dioxide precipitate, which is then removed.

[0102] In this embodiment, the amylopyrime material reaches its maximum catalytic reduction capacity after 6 hours of continuous passage through uranium-containing wastewater at a flux of 3000 LMH. The adsorption rate of uranium is ≥98%, and the reduction rate is also ≥98%. After long-term use, the precipitated uranium dioxide will clog the device. The precipitated uranium dioxide can be eluted with nitric acid, so that the amylopyrime material can continue to be used. The adsorption-reduction rate can still be maintained at ≥95% after 5 uses, and the adsorption-reduction rate drops to 87.3% after the 6th use.

[0103] During the adsorption-reduction process of uranium in uranium-containing wastewater by the aforementioned amylopyroxime material, the lower limit of uranium content is 3 ppb.

[0104] like Figure 1 The image shows a scanning electron microscope (SEM) image of the Schiff base reaction precursor described in Example 1. As can be seen from the image, the amino monomer and aldehyde monomer in this example form a flower-like structure under the action of a catalyst and a regulator.

[0105] like Figure 2 and 3 The images show transmission electron microscopy (TEM) images and magnified TEM images of the amine oxime material described in Example 1. As can be seen from the images, the flower-like structure in this example has uniformly dispersed metal particles of the same size.

[0106] like Figure 4 The X-ray diffraction pattern of the material in Example 1 shows that the cyano-addition covalent organic framework support, the metal-loaded covalent organic framework material, and the amylopectin material all have (100) and (200) crystal planes corresponding to the covalent organic framework (COF) at 2.79° and 5.58°. The metal-loaded covalent organic framework material and the amylopectin material have a (111) crystal plane of metallic gold at 38.23°, but it is not obvious in the figure due to the small amount of gold loading.

[0107] like Figure 5 The image shows the infrared spectrum of the material used in Example 1. The cyano-addition covalent organic framework support and the metal-supported covalent organic framework material are shown at 2250 ± 0.01 cm⁻¹. -1 A stretching vibration peak of -CN appears at [location missing], while the peak of the mercapto group (-SH) is not obvious due to being blocked. In the amine oxime material, the cyano group is converted to [value missing] at 1620±0.01 cm⁻¹. -1 The stretching vibration peaks of -C=N and -OH at the position indicate that the cyano group has been converted into a metamine oxime group, and the peaks at 500-1500±0.01cm -1 The characteristic peak corresponding to the COF framework is located at this point.

[0108] like Figure 6 The figure shows the reduction rate test of the amylopyroxime material described in Example 1. As can be seen from the figure, in the simulated static catalytic reduction experiment, the material can achieve a uranium reduction rate of more than 90% within 10 minutes, with high adsorption-reduction efficiency. After 30 minutes, the reduction rate can reach more than 98%, which significantly improves the adsorption-reduction rate of uranium by the material.

[0109] like Figure 7 This is a specific surface area diagram of the materials at different stages in Example 1. As shown in the diagram, the specific surface area of ​​the Schiff base precursor is 2051 m². 2 / g, after cyano addition and metal loading, the specific surface area decreased to 764m². 2 / g, the specific surface area after the cyano group is converted into a amine oxime group is 571m². 2 / g, the specific surface area gradually decreases, but the number of active groups increases.

[0110] Example 2

[0111] This embodiment provides a methylamine oxime material, wherein the specific surface area (BET value) of the methylamine oxime material is 546 m². 2 / g, pore volume is 0.70cm³ 3 / g, with an average pore size of 3.51nm; after soaking under acidic conditions, soaking under alkaline conditions, and placing at a high temperature of 200℃, the specific surface area, pore volume, and pore size remained unchanged.

[0112] This embodiment also provides a method for preparing the aforementioned amine oxime material, comprising the following steps:

[0113] Step 1: 14.16 mg (0.04 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 11.12 mg (0.06 mmol) of 2,5-divinyl-1,4-phenylenedialdehyde were dispersed in 5 mL of acetonitrile by stirring at 400 rpm for 10 min. 0.3 mL of acetic acid and 0.024 mL of aniline were added, and the mixture was sonicated for 10 min. The temperature was then raised to 40 °C and reacted for 75 h. After the reaction was completed, the mixture was centrifuged at 10,000 rpm for 5 min, washed three times with tetrahydrofuran and ethanol respectively, and dried at 80 °C and 0.08 MPa for 24 h to obtain the Schiff base reaction precursor.

[0114] Step 2: 0.12 g of the Schiff base reaction precursor, 0.14 g of disodium dimercaptomalenitrogenate and 0.015 g of azobisisobutyronitrile were dispersed in 10 mL of N,N-dimethylformamide at 400 rpm. The mixture was then placed under a nitrogen atmosphere and heated to 100 °C for 2.5 days. After the reaction was completed, the mixture was centrifuged at 10,000 rpm for 5 min, washed three times with acetone and ethanol respectively, and dried at 80 °C and 0.08 MPa for 24 h to obtain the cyano addition covalent organic framework support.

[0115] Step 3: Disperse 0.12g of the cyano addition covalent organic framework support and 3.75mL of 0.1wt% tetrachloroauric acid solution in 52.5mL of tetrahydrofuran and mechanically shake at 55 times / min for 2h in the dark. Then add 15mL of 13.3mg / L sodium borohydride solution (solvent is tetrahydrofuran) and continue to mechanically shake at 55 times / min for 2h in the dark for reduction reaction. After the reaction is completed, centrifuge at 10000rpm for 5min, wash 5 times with acetone and ethanol respectively, and dry at 80℃ and 0.08MPa for 24h to obtain the metal-supported covalent organic framework material.

[0116] Step 4: Add 0.1g of the metal-supported covalent organic framework material to 0.2g of sodium carbonate and 0.2g of hydroxylamine hydrochloride, dissolve in 10g of deionized water and 20g of ethanol at 500rpm, and stir for 10h to convert the cyano group. After the reaction is completed, centrifuge at 10000rpm for 5min, wash three times with acetone and deionized water respectively, and dry at 80℃ and 0.08MPa for 24h to obtain the metamine oxime material.

[0117] Example 3

[0118] This embodiment provides a metallo-oxime material with a specific surface area (BET value) of 600 m². 2 / g, pore volume is 0.76cm³ 3 / g, with an average pore size of 3.34nm; after soaking under acidic conditions, soaking under alkaline conditions, and placing at a high temperature of 200℃, the specific surface area, pore volume, and pore size remained unchanged.

[0119] This embodiment also provides a method for preparing the aforementioned amine oxime material, comprising the following steps:

[0120] Step 1: 14.16 mg (0.04 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 11.12 mg (0.06 mmol) of 2,5-divinyl-1,4-phenylenedialdehyde were dispersed in 5 mL of acetonitrile by stirring at 300 rpm for 10 min. 0.3 mL of acetic acid and 0.024 mL of aniline were added, and the mixture was sonicated for 5 min. The temperature was then raised to 30 °C and reacted for 72 h. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with tetrahydrofuran and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the Schiff base reaction precursor.

[0121] Step 2: 0.12 g of the Schiff base reaction precursor, 0.14 g of disodium dimercaptomalenitrogenate and 0.015 g of azobisisobutyronitrile were dispersed in 10 mL of N,N-dimethylformamide at 300 rpm. The mixture was then placed under a nitrogen atmosphere and heated to 80 °C for 2 days. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with acetone and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the cyano addition covalent organic framework support.

[0122] Step 3: Disperse 0.1g of the cyano addition covalent organic framework support and 3.75mL of 0.1wt% tetrachloroauric acid solution in 52.5mL of tetrahydrofuran and mechanically shake at 60 times / min for 3h in the dark. Then add 15mL of 13.3mg / L sodium borohydride solution (solvent is tetrahydrofuran) and continue to mechanically shake at 60 times / min for 3h in the dark for reduction reaction. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and ethanol respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the metal-supported covalent organic framework material.

[0123] Step 4: Add 0.1g of the metal-supported covalent organic framework material to 0.2g of sodium carbonate and 0.2g of hydroxylamine hydrochloride, dissolve in 10g of deionized water and 20g of ethanol at 300rpm, and stir for 7h to convert the cyano group. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and deionized water respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the metamine oxime material.

[0124] Comparative Example 1

[0125] This comparative example provides a material with a specific surface area (BET value) of 12 m². 2 / g, pore volume is 0.38cm³ 3 / g, with an average pore size of 3.08nm.

[0126] This comparison also provides a method for preparing the material, comprising the following steps:

[0127] Step 1: 14.16 mg (0.04 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 11.12 mg (0.06 mmol) of 2,5-divinyl-1,4-phenylenedialdehyde were dispersed in 5 mL of acetonitrile by stirring at 300 rpm for 10 min. 0.3 mL of acetic acid was added, and the mixture was sonicated for 5 min. The temperature was then raised to 30 °C and reacted for 72 h. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with tetrahydrofuran and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the Schiff base reaction precursor.

[0128] Step 2: 0.12 g of the Schiff base reaction precursor, 0.14 g of disodium dimercaptomalenitrogenate and 0.015 g of azobisisobutyronitrile were dispersed in 10 mL of N,N-dimethylformamide at 300 rpm. The mixture was then placed under a nitrogen atmosphere and heated to 80 °C for 2 days. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with acetone and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the cyano addition covalent organic framework support.

[0129] Step 3: Disperse 0.1g of the cyano addition covalent organic framework support and 3.75mL of 0.1wt% tetrachloroauric acid solution in 52.5mL of tetrahydrofuran and mechanically shake at 60 times / min for 3h in the dark. Then add 15mL of 13.3mg / L sodium borohydride solution (solvent is tetrahydrofuran) and continue to mechanically shake at 60 times / min for 3h in the dark for reduction reaction. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and ethanol respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the metal-supported covalent organic framework material.

[0130] Step 4: Add 0.1g of the metal-supported covalent organic framework material to 0.2g of sodium carbonate and 0.2g of hydroxylamine hydrochloride, dissolve in 10g of deionized water and 20g of ethanol at 300rpm, and stir for 7h to convert the cyano group. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and deionized water respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the material.

[0131] like Figure 8 and 9 The images show scanning electron microscope (SEM) images and magnified SEM images of the material described in Comparative Example 1. The material in the images has a spherical structure, but not a flower-like morphology.

[0132] Comparative Example 2

[0133] This comparative example provides a material with a specific surface area (BET value) of 250 m². 2 / g, pore volume is 0.49cm³ 3 / g, with an average pore size of 3.62nm.

[0134] This comparison also provides a method for preparing the material, comprising the following steps:

[0135] Step 1: 14.16 mg (0.04 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 11.12 mg (0.06 mmol) of 2,5-divinyl-1,4-phenylenedialdehyde were dispersed in 5 mL of acetonitrile by stirring at 300 rpm for 10 min. 0.3 mL of acetic acid and 0.024 mL of aniline were added, and the mixture was sonicated for 5 min. The reaction was then carried out at 20 °C for 72 h. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times each with tetrahydrofuran and ethanol, and dried at 60 °C and -0.1 MPa for 12 h to obtain the Schiff base reaction precursor, which had a specific surface area of ​​1738 m². 2 / g;

[0136] Step 2: 0.12 g of the Schiff base reaction precursor, 0.14 g of disodium dimercaptomalenitrogenate and 0.015 g of azobisisobutyronitrile were dispersed in 10 mL of N,N-dimethylformamide at 300 rpm. The mixture was then placed under a nitrogen atmosphere and heated to 80 °C for 2 days. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with acetone and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the cyano addition covalent organic framework support.

[0137] Step 3: Disperse 0.1g of the cyano addition covalent organic framework support and 3.75mL of 0.1wt% tetrachloroauric acid solution in 52.5mL of tetrahydrofuran and mechanically shake at 60 times / min for 3h in the dark. Then add 15mL of 13.3mg / L sodium borohydride solution (solvent is tetrahydrofuran) and continue to mechanically shake at 60 times / min for 3h in the dark for reduction reaction. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and ethanol respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the metal-supported covalent organic framework material.

[0138] Step 4: Add 0.1g of the metal-supported covalent organic framework material to 0.2g of sodium carbonate and 0.2g of hydroxylamine hydrochloride, dissolve in 10g of deionized water and 20g of ethanol at 300rpm, and stir for 7h to convert the cyano group. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and deionized water respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the material.

[0139] Comparative Example 3

[0140] This comparative example provides a material with a specific surface area (BET value) of 16 m². 2 / g, pore volume is 0.32cm³ 3 / g, with an average pore size of 3.38nm.

[0141] This comparison also provides a method for preparing the material, comprising the following steps:

[0142] Step 1: 14.16 mg (0.04 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 11.12 mg of trialdehyde phloroglucinol were dispersed in 5 mL of acetonitrile by stirring at 300 rpm for 10 min. 0.3 mL of acetic acid and 0.024 mL of aniline were added, and the mixture was sonicated for 5 min. The temperature was then raised to 30 °C and reacted for 72 h. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with tetrahydrofuran and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the Schiff base reaction precursor.

[0143] Step 2: 0.12 g of the Schiff base reaction precursor, 0.14 g of disodium dimercaptomalenitrogenate and 0.015 g of azobisisobutyronitrile were dispersed in 10 mL of N,N-dimethylformamide at 300 rpm. The mixture was then placed under a nitrogen atmosphere and heated to 80 °C for 2 days. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with acetone and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the cyano addition covalent organic framework support.

[0144] Step 3: Disperse 0.1g of the cyano addition covalent organic framework support and 3.75mL of 0.1wt% tetrachloroauric acid solution in 52.5mL of tetrahydrofuran and mechanically shake at 60 times / min for 3h in the dark. Then add 15mL of 13.3mg / L sodium borohydride solution (solvent is tetrahydrofuran) and continue to mechanically shake at 60 times / min for 3h in the dark for reduction reaction. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and ethanol respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the metal-supported covalent organic framework material.

[0145] Step 4: Add 0.1g of the metal-supported covalent organic framework material to 0.2g of sodium carbonate and 0.2g of hydroxylamine hydrochloride, dissolve in 10g of deionized water and 20g of ethanol at 300rpm, and stir for 7h to convert the cyano group. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and deionized water respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the material.

[0146] Comparative Example 4

[0147] This comparative example provides a material with a specific surface area (BET value) of 553 m². 2 / g, pore volume is 0.75cm³ 3 / g, with an average pore size of 3.23nm.

[0148] This comparison also provides a method for preparing the material, comprising the following steps:

[0149] Step 1: 14.16 mg (0.04 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 11.12 mg (0.06 mmol) of 2,5-divinyl-1,4-phenylenedialdehyde were dispersed in 5 mL of acetonitrile by stirring at 300 rpm for 10 min. 0.3 mL of acetic acid and 0.024 mL of aniline were added, and the mixture was sonicated for 5 min. The temperature was then raised to 30 °C and reacted for 72 h. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with tetrahydrofuran and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the Schiff base reaction precursor.

[0150] Step 2: 0.12 g of the Schiff base reaction precursor, 0.14 g of disodium dimercaptomalenitrogenate and 0.015 g of azobisisobutyronitrile were dispersed in 10 mL of N,N-dimethylformamide at 300 rpm. The mixture was then placed under a nitrogen atmosphere and heated to 80 °C for 2 days. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, washed three times with acetone and ethanol respectively, and dried at 60 °C and -0.1 MPa for 12 h to obtain the cyano addition covalent organic framework support.

[0151] Step 3: Disperse 0.1g of the cyano addition covalent organic framework carrier and 3.75mL of 0.1wt% tetrachloroauric acid solution in 52.5mL of tetrahydrofuran and mechanically shake at 60 times / min for 3h in the dark. Then add 15mL of 13.3mg / L sodium borohydride solution (solvent is tetrahydrofuran) and continue mechanically shaking at 60 times / min for 3h in the dark for reduction reaction. After the reaction is completed, centrifuge at 8000rpm for 10min, wash three times with acetone and ethanol respectively, and dry at 60℃ and -0.1MPa for 12h to obtain the material.

[0152] Table 1 shows the properties of the materials used in this embodiment and the comparative example.

[0153]

[0154] As shown in Table 1, the amylopectin materials in this embodiment have high specific surface area and high pore volume. In Comparative Example 1, no aniline was added, and in Comparative Example 3, the aldehyde monomer was not a specific raw material in this invention. Both of these factors resulted in the materials in the comparative examples being unable to generate a high specific surface area structure with a flower-like morphology. In Comparative Example 2, the Schiff base reaction process was at a low temperature, and the dehydration condensation process of the amino and aldehyde groups was too slow, resulting in a small specific surface area of ​​the obtained material. In Comparative Example 4, the material did not undergo the conversion from cyano to amylopectin groups. Although the specific surface area remained unchanged, its response to heavy metals was relatively reduced. Under the same conditions, the adsorption-reduction rate of uranium was only 92%.

[0155] The specific conditions for soaking under acidic conditions in this invention are soaking in aqua regia for 24 hours, soaking under alkaline conditions are soaking in NaOH with pH=11 for 24 hours, and placing at a high temperature of 200°C for 48 hours.

[0156] As can be seen from the above, the amylopyroxime material described in this invention has a wide range of applications, low cost, and a very high market prospect.

[0157] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A methylamine oxime material, characterized in that, The amine oxime material is prepared by the following method: Step 1: The amino monomer and aldehyde monomer are heated and dispersed under the action of a catalyst and a regulator to react. After the reaction is completed, the obtained solid is centrifuged, washed and dried to obtain the Schiff base reaction precursor. Step 2: The Schiff base reaction precursor and cyano monomer are heated and dispersed under the action of an initiator to react. After the reaction is completed, the obtained solid is centrifuged, washed and dried to obtain a cyano addition covalent organic framework support. Step 3: After the cyano addition covalent organic framework carrier and the metal ion monomer undergo a light-protected reaction, a reducing agent is added to continue the reduction reaction under light-protected conditions. After the reaction is completed, the obtained solid is centrifuged, washed, and dried to obtain the metal-supported covalent organic framework material. Step 4: Add the metal-supported covalent organic framework material to the carbonate monomer and the amine oxime material and stir to convert the cyano group. After the reaction is complete, centrifuge the obtained solid, wash and dry it to obtain the amine oxime material. The volume ratio of the catalyst and the regulator in step 1 is (12:1) - (13:1). The solvent used for heating and dispersing in step 1 is acetonitrile, and the volume ratio of acetonitrile to the catalyst is (15:1)-(17:1). The mass-to-volume ratio of the amino monomer to the solvent is (14-15 mg): 5 mL; The heating and dispersion temperature in step 1 is 30-40℃; The amino monomer in step 1 is 1,3,5-tris(4-aminophenyl)benzene; The aldehyde monomer in step 1 is 2,5-divinyl-1,4-phenylenedialdehyde; The regulator in step 1 is aniline; In step 2, the mass ratio of the Schiff base reaction precursor, the cyano monomer, and the initiator is (0.1-0.12):(0.13-0.15):(0.012-0.015). The cyano monomer in step 2 is disodium dimercaptomalenitrogenate; In step 3, the mass-to-volume ratio of the cyano addition covalent organic framework carrier, the metal ion monomer, and the reducing agent is (0.1-0.12 g): (3-4 mL): (15-17 mL). The metal in the metal ion monomer in step 3 is gold; The carbonate monomer mentioned in step 4 is sodium carbonate.

2. The geminal oxime material according to claim 1, characterized in that, The described methanogen material has a flower-like structure and a specific surface area of ​​540-610 m². 2 / g, pore volume is 0.70-0.76cm³ 3 / g, with an average pore size of 3.30-3.60nm; after soaking under acidic conditions, soaking under alkaline conditions, and placing at a high temperature of 200℃, the specific surface area, pore volume, and pore size remain unchanged.

3. A method for preparing the amine oxime material according to any one of claims 1-2, characterized in that, Includes the following steps: Step 1: The amino monomer and aldehyde monomer are heated and dispersed under the action of a catalyst and a regulator to react. After the reaction is completed, the obtained solid is centrifuged, washed and dried to obtain the Schiff base reaction precursor. Step 2: The Schiff base reaction precursor and cyano monomer are heated and dispersed under the action of an initiator to react. After the reaction is completed, the obtained solid is centrifuged, washed and dried to obtain a cyano addition covalent organic framework support. Step 3: After the cyano addition covalent organic framework carrier and the metal ion monomer undergo a light-protected reaction, a reducing agent is added to continue the reduction reaction under light-protected conditions. After the reaction is completed, the obtained solid is centrifuged, washed, and dried to obtain the metal-supported covalent organic framework material. Step 4: Add the metal-supported covalent organic framework material to the carbonate monomer and the amine oxime material and stir to convert the cyano group. After the reaction is complete, centrifuge the obtained solid, wash and dry it to obtain the amine oxime material.

4. The preparation method according to claim 3, characterized in that, In the X-ray diffraction test, the cyano-addition covalent organic framework support in step 2, the metal-loaded covalent organic framework material in step 3, and the amylopyroxime material in step 4 all showed (100) and (200) crystal planes corresponding to the covalent organic framework at 2.79° and 5.58°. The metal-loaded covalent organic framework material in step 3 and the amylopyroxime material in step 4 have a (111) crystal plane of metallic gold at 38.23°, but the peak is not obvious due to the low loading of gold.

5. The preparation method according to claim 3, characterized in that, In the infrared spectroscopy tests of the cyano-addition covalent organic framework support in step 2, the metal-supported covalent organic framework material in step 3, and the amine oxime material in step 4, the cyano-addition covalent organic framework support and the metal-supported covalent organic framework material showed values ​​around 2250 ± 0.01 cm⁻¹. -1 A -CN stretching vibration peak appears at [location missing], while the peak for the thiol group is not obvious due to being blocked. In the described amylopyridine oxime material, the cyano group is converted to [value missing] at 1620±0.01 cm⁻¹. -1 The stretching vibration peaks of -C=N and -OH at the position prove that the cyano group has been converted into a amine oxime group.

6. A heavy metal adsorbent, characterized in that, The heavy metal adsorbent is the amylopyroxime material according to any one of claims 1-2.

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