Preparation method of two-dimensional polymer nanosheet adsorbent controllably constructed through micelle assembly and application of two-dimensional polymer nanosheet adsorbent

Abstract

The invention belongs to the technical field of preparation of molecular identification adsorption separation functional materials, and discloses a preparation method and application of a two-dimensional polymer nanosheet adsorbent controllably constructed by micelle assembly. According to the invention, a micelle assembly strategy and an ice template method are introduced to construct the two-dimensional polymer nanosheet adsorbent so as to specifically separate adenosine monophosphate AMP in nucleoside compounds. Tetravinyl phenylboronic acid (4-VPBA) and tetraethyl orthosilicate (TEOS) are used as monomers, sodium dodecyl sulfate (SDS) is used as a micelle to provide a confinement space to wrap the monomers for micelle assembly, and the two-dimensional polymer nanosheet 2DPS-BA with specific adenosine monophosphate separation capacity is successfully synthesized through an ice template method. Different silane coupling agents are used for replacing tetravinyl phenylboronic acid to serve as monomers, the two-dimensional polymer nanosheet is successfully prepared, the applicability of the work is proved, and the method has potential application value in the field of identification and separation.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of molecular recognition adsorption and separation functional materials, and specifically relates to a preparation method of a micelle assembly controllably constructed two-dimensional polymer nanosheet adsorbent and its adsorption and separation application. Background Art

[0002] Two-dimensional nanomaterials are single- or multilayer structures with nanometer-scale thickness and large surface areas within a plane. Due to their ultrathin two-dimensional structure, high aspect ratio, and excellent mechanical properties, they are widely used in electronics, energy, catalysis, biology, and adsorption. Currently, common two-dimensional nanomaterials include two-dimensional polymer nanosheets, graphene, black phosphorus, MXene, boron nitride, and carbon nitride. Two-dimensional polymer nanosheets, with their rich surface groups and easy modification, are ideal materials for preparing two-dimensional adsorbents and have shown great potential in the adsorption field. Traditional methods for preparing two-dimensional polymer nanosheets include exfoliation, chemical vapor deposition, template-based polymerization, interfacial polymerization, and solvothermal methods. However, these methods suffer from difficulties in scalable production and limited applicability. Existing thermally initiated polymerization methods typically require temperatures exceeding 60°C, making it difficult to effectively control the reaction process at these elevated temperatures, hindering the precise control of the structure of two-dimensional polymer nanosheets. Furthermore, traditional polymerization processes often use large amounts of organic solvents, which pollute the environment and increase costs. Therefore, developing a precise, controllable, and green strategy is of great significance for the preparation of two-dimensional polymer nanosheet adsorbents.

[0003] Micellar assembly is the process by which amphiphilic micelle molecules self-assemble in a solvent to form supramolecular structures, leveraging non-covalent forces such as hydrophobic interactions, electrostatic interactions, and hydrogen bonds. Micellar assembly can be used to prepare materials with a variety of complex morphologies, such as spherical, cylindrical, sheet-like, and star-shaped materials. Furthermore, by fine-tuning the micelle assembly environment, micelle type, and concentration, the morphology and properties of the materials can be precisely controlled. Nanosheets provide a platform for this. However, the synthesis of two-dimensional polymer nanosheets using micellar assembly alone is still limited by low yields. The ice-templating method is a scalable method for preparing two-dimensional polymer nanosheets. It uses solidified ice as a hard template, entropy-driven self-assembly of dispersed nanomaterials at ice crystal boundaries. This method offers advantages such as being green, low-carbon, environmentally friendly, and widely applicable. The mechanical properties and stability of materials prepared using ice-templating have been a research focus, and these materials typically require pre-compounding or post-treatment to enhance their mechanical properties. In order to improve the stability of the material, this work considers using silane coupling agents as monomers. The polymerization of silane coupling agents can be carried out preferentially before micelle assembly. Then, through micelle assembly, the micelle entropy is driven to the ice crystal boundary for self-assembly in combination with the ice template method, thereby realizing interface-directed assembly to prepare two-dimensional polymer nanosheet materials. However, the nanosheet adsorbents prepared using only silane coupling agents lack the specific adsorption capacity for the target object.

[0004] Selectivity is an important parameter for evaluating the performance of adsorbents. The selectivity of two-dimensional polymer nanosheet adsorbents usually depends on the specific chemical interactions generated by surface functional groups. For different targets, the selection of recognition sites generated by different functional groups has an important influence on the recognition and separation performance of the adsorbent. For example, adenosine monophosphate (AMP), a typical representative of nucleosides, has adenine, cis-dihydroxyl, amino, and phosphate functional groups. Among them, the cis-dihydroxyl can undergo boron affinity covalent interaction with the boric acid functional group, adenine can undergo base complementary pairing with the pyrimidine functional group, and the phosphate functional group can coordinate with metal ions. Therefore, modification of the functional groups can significantly improve the selective recognition effect of two-dimensional polymer nanosheet adsorbents.

[0005] Therefore, the present invention utilizes micellar silane coupling agents and polymerizable monomers, utilizes the confined space inside the micelles to cause polymerization, and combines the ice template method to drive the micelle assembly behavior to assemble micellar nanoparticles into two-dimensional polymer nanosheet adsorbents. By studying factors such as the type of micelles, the type and amount of monomers, and the polymerization time, the morphology of the two-dimensional polymer nanosheets is precisely controlled, and a selective two-dimensional polymer nanosheet adsorbent can be controllably constructed and used for the selective adsorption and separation of AMP. Summary of the Invention

[0006] In response to the shortcomings of existing technologies, this work provides a method for controllably constructing two-dimensional polymer nanosheet adsorbents through micelle assembly and ice template strategy to solve the problems of controllable preparation and selectivity of existing two-dimensional polymer nanosheets, and is used for the selective separation of adenosine monophosphate (AMP).

[0007] The present invention uses tetravinylphenylboronic acid (4VPBA) and tetraethyl orthosilicate (TEOS) as functional monomers and sodium dodecylsulfonate (SDS) as a micelle template to prepare two-dimensional polymer nanosheets via an ice-templated method. The specific steps are as follows: 4VPBA and TEOS are dissolved in an SDS micelle solution, ultrasonically dispersed, and then ammonia (NH3·H2O) is added to adjust the solution pH to an alkaline range. Ammonium persulfate (APS) is then added to initiate polymerization. After standing for a period of time, the mixture is rapidly frozen with liquid nitrogen. After polymerization at low temperatures for a certain period of time, it is freeze-dried to obtain a two-dimensional polymer nanosheet adsorbent with micelles. After removing the micelles, a two-dimensional polymer nanosheet adsorbent with boronic acid functional groups (2DPS-BA) is obtained. At the same time, this work also used other silane coupling agents 3-aminopropyltriethoxysilane (APTES), 3-chloropropyltrimethoxysilane (CPTES), 3-glycidoxypropyltriethoxysilane (GPTES) and 3-mercaptopropyltrimethoxysilane (MPTES) to replace the 4-VPBA monomer and successfully prepared two-dimensional polymer nanosheet adsorbents with different functional groups, demonstrating the wide applicability of this method and enriching the functions of two-dimensional polymer nanosheets.

[0008] A method for preparing a two-dimensional polymer nanosheet adsorbent by controllable micelle assembly comprises the following steps:

[0009] (1) Preparation of 2DPS-BA:

[0010] First, an SDS solution is prepared. SDS will form a micelle structure in the solution. Then, the monomer 4VPBA, the crosslinker TEOS, and the initiator APS are added to the SDS solution in proportion. Ammonia water is added by ultrasonication to adjust the pH value to 8-9. The mixture is allowed to stand at room temperature for a period of time to ensure that the monomer, TEOS, and APS fully enter the micelles before polymerization occurs. After the standing period, the mixture is rapidly frozen using liquid nitrogen and polymerized at low temperature. After the polymerization is completed, the mixture is freeze-dried to obtain a two-dimensional polymer nanosheet. The polymer nanosheet prepared by the above process is dissolved in deionized water, ultrasonicated, and centrifuged and filtered several times until the filtrate no longer produces foam during the ultrasonication process. The mixture is then freeze-dried again to obtain a two-dimensional polymer nanosheet 2DPS-BA.

[0011] (2) Preparation of two-dimensional polymer nanosheets with different functional groups:

[0012] First, an SDS solution is prepared. SDS will form a micelle structure in the solution. Then, the monomer APTES and the crosslinker TEOS are added to the SDS solution in proportion. Ammonia water is added by ultrasonication to adjust the pH value to 8-9. The mixture is allowed to stand at room temperature for a period of time to ensure that APTES and TEOS fully enter the micelles and then polymerize. After the standing period, liquid nitrogen is used for rapid freezing, low-temperature polymerization is carried out, and freeze-drying is performed after the polymerization is completed to obtain two-dimensional polymer nanosheets. The polymer nanosheets prepared by the above process are dissolved in deionized water, ultrasonicated, and centrifuged and filtered. This process is repeated several times until the filtrate no longer produces foam during the ultrasonication process. The filtrate is then freeze-dried again to obtain two-dimensional polymer nanosheets 2DPS-NH.

[0013] (3) The APTES in step (2) was replaced with CPTES, GPTES, and MPTES in sequence, and the above operation was repeated to obtain polymer nanosheets 2DPS-Cl with chlorine groups, polymer nanosheets 2DPS-EP with epoxy bonds, and polymer nanosheets 2DPS-SH with thiol groups.

[0014] In step (1), the dosage ratio of the 4VPBA, TEOS, APS and SDS solution is 1.3 mg: 1.0.-1.5 μL: 2.0-2.5 mg: 0.8-1.0 mL, wherein the concentration of the SDS solution is 200-300 mM.

[0015] In step (1), the temperature of the low-temperature polymerization is -20°C, and the time of the low-temperature polymerization is 72-120 hours.

[0016] In step (2), the usage ratio of the APTES or CPTES or GPTES or MPTES, TEOS and SDS solution is 1.0 μL:1.0-2.0 μL:0.8-1.0 mL, wherein the concentration of the SDS solution is 200-300 mM.

[0017] In step (2), the temperature of the low-temperature polymerization is -20°C, and the time of the low-temperature polymerization is 48-96 hours.

[0018] In steps (1) and (2), the freeze-drying temperature is -60°C.

[0019] In steps (1) and (2), when deionized water is used to dissolve the prepared polymer nanosheets, the temperature of the deionized water is 20-40°C.

[0020] In step (1) and step (2), the centrifugal speed is 10000 rpm, the stirring time is 3-10 min, and the number of times is 3-5 times.

[0021] The two-dimensional polymer nanosheets or the two-dimensional polymer nanosheets with functional groups prepared by the present invention are used for selectively separating adenosine monophosphate (AMP).

[0022] Compared with existing detection technologies, the present invention has the following beneficial effects:

[0023] This work introduces a micellar assembly strategy and ice-templating method to construct two-dimensional polymer nanosheet adsorbents. Using tetravinylphenylboronic acid (4VPBA) as a monomer, tetraethyl orthosilicate (TEOS) as a crosslinker, and sodium dodecylsulfonate (SDS) as a micelle-encapsulated monomer for assembly, two-dimensional polymer nanosheets were successfully synthesized via the ice-templating method. Simultaneously, the monomers were replaced with APTES, CPTES, GPTES, and MPTES, all resulting in successful two-dimensional polymer nanosheet preparation. This provides a new approach for the synthesis of two-dimensional polymer nanosheet materials. By simply adjusting the ratio of monomer to silane coupling agent and the reaction conditions, the morphology, size, and rigidity of the two-dimensional polymer nanosheets can be finely tuned, showing potential applications in adsorption separations. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The scanning electron microscope images of 2DPS-BA, 2DPS-NH, 2DPS-Cl, 2DPS-EP, and 2DPS-SH prepared in Example 1 are obtained by adjusting the amount of TEOS.

[0025] Figure 2 This is a scanning electron micrograph of the polymerization time regulation of 2DPS-BA, 2DPS-NH, 2DPS-Cl, 2DPS-EP, and 2DPS-SH in Example 1.

[0026] Figure 3 These are scanning electron micrographs of different regulated micelles SDS (a), F127 (b), and P123 (c) of 2DPS-Cl prepared in Example 1.

[0027] Figure 4 This is a transmission electron micrograph of the SDS solution prepared in Example 1.

[0028] Figure 5 This is a surface tension test diagram of the SDS solution prepared in Example 1.

[0029] Figure 6 The contact angles of 2DPS-NH (a), 2DPS-BA (b), 2DPS-Cl (c), 2DPS-EP (d), 2DPS-SH (e), and PTEOS (f) prepared in Example 1.

[0030] Figure 7The infrared spectra of 2DPS-NH (a), 2DPS-BA (b), 2DPS-Cl (c), 2DPS-EP (d), and 2DPS-SH (e) prepared in Example 1 are shown.

[0031] Figure 8 Dynamic light scattering diagrams of 2DPS-NH (a), 2DPS-BA (b), 2DPS-Cl (c), 2DPS-EP (d), 2DPS-SH (e), and PTEOS (f) prepared in Example 1.

[0032] Figure 9 The adsorption kinetics and model fitting curve of 2DPS-BA prepared in Example 1.

[0033] Figure 10 The adsorption equilibrium of 2DPS-BA and its model fitting curve in Example 1.

[0034] Figure 11 The adsorption selectivity of 2DPS-BA in Example 1 and its model fitting curve.

[0035] Figure 12 is the regeneration adsorption capacity of 2DPS-BA in Example 1. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to specific embodiments and drawings.

[0037] In the specific implementation of the present invention, the recognition performance evaluation is performed according to the following method:

[0038] 2 mL of a certain concentration of AMP solution was added to a centrifuge tube, along with a certain amount of 2DPS-BA adsorbent. The tube was then placed in a 25°C constant temperature and humidity chamber for several hours. The AMP content after adsorption was measured using a UV-visible spectrophotometer, and the adsorption capacity was calculated based on the results. 2 mL of an AMP solution with an initial concentration of 300 μmol / L was added to a centrifuge tube, along with a certain amount of 2DPS-BA adsorbent. The adsorption capacity was calculated based on the results and used to study the kinetic properties of the 2DPS-BA adsorbent. Several nucleoside compounds with similar structures and properties, such as adenosine (A), 2-deoxyadenosine (dA), and adenosine monophosphate (AMP), were selected as target molecules to study the selective recognition properties of the adsorbent.

[0039] The present invention will be further described below with reference to specific implementation examples.

[0040] Example 1:

[0041] (1) Preparation of 2DPS-BA:

[0042] First, weigh 7.2g of SDS and prepare a 250mM SDS solution. SDS will form a micelle structure in the solution. Then take 9.0mL of SDS solution, add 12.6mg of 4VPBA, 10.0μLTEOS and 23.3mgAPS to the SDS solution, add 0.5μL of ammonia water by ultrasonication to adjust the pH value to 8-9, and let the mixture stand at room temperature for 12h to ensure that the monomer, TEOS and APS fully enter the micelles before polymerization occurs; after the polymerization is completed, use liquid nitrogen to quickly freeze for 10min, and polymerize at -20℃ for 120h. After the polymerization is completed, freeze and dry to obtain two-dimensional polymer nanosheets. Use 30℃ deionized water to dissolve the polymer nanosheets prepared by the above process, ultrasonicate, centrifuge and filter several times until the filtrate no longer produces foam during the ultrasonication process. Freeze and dry again to obtain two-dimensional polymer nanosheets 2DPS-BA;

[0043] (2) Preparation of 2DPS-NH, 2DPS-Cl, 2DPS-EP, and 2DPS-SH:

[0044] First, weigh 7.2g of SDS and prepare a 250mM SDS solution. SDS will form a micelle structure in the solution. Then take 9.0mL of SDS solution, add 10.0μL APTES and 15.0μL TEOS to the SDS solution, add ammonia water by ultrasonication to adjust the pH value to 8-9, and let the mixture stand at room temperature for 12h to ensure that APTES and TEOS fully enter the interior of the micelles before polymerization occurs; after the polymerization is completed, use liquid nitrogen to quickly freeze for 10min, and polymerize at -20℃ for 72h. Use 30℃ deionized water to dissolve the polymer nanosheets prepared by the above process, ultrasonicate, centrifuge and filter, and repeat several times until the filtrate no longer produces foam during the ultrasonication process. Freeze-dry again to obtain two-dimensional polymer nanosheets 2DPS-NH;

[0045] Replace the SDS micelles with F127 and P123 and repeat the above steps;

[0046] Only TEOS was added to the SDS solution and the above steps were repeated to obtain PTEOS;

[0047] (3) The APTES:TEOS=10.0μL:15.0μL in step (2) was changed to CPTES:TEOS=10.0μL:15.0μL, GPTES:TEOS=10.0μL:15.0μL, and MPTES:TEOS=10.0μL:10.0μL, respectively, and the above operation was repeated to obtain two-dimensional polymer nanosheets 2DPS-Cl with chlorine groups, two-dimensional polymer nanosheets 2DPS-EP with epoxy bonds, and two-dimensional polymer nanosheets 2DPS-SH with thiol groups.

[0048] Figure 1 Scanning electron micrographs of 2DPS-BA (a1, a2), 2DPS-NH (b1-b4), 2DPS-Cl (c1-c4), 2DPS-EP (d1-d4), and 2DPS-SH (e1-e4) prepared in Example 1, as determined by adjusting the TEOS dosage. The images show that 2DPS-NH, 2DPS-BA, 2DPS-Cl, 2DPS-EP, and 2DPS-SH all clearly form two-dimensional polymers, demonstrating the universality of this method and the ability to generate two-dimensional polymer nanosheets using a variety of materials.

[0049] Figure 2 The SEM images of the polymerization time-controlled polymerization of 2DPS-BA (a1-a3), 2DPS-NH (b1-b3), 2DPS-Cl (c1-c3), 2DPS-EP (d1-d3), and 2DPS-SH (e1-e3) in Example 1 are shown. The images show that the polymerization time has a significant impact on the morphology of the final product.

[0050] Figure 3 The following are scanning electron micrographs of two-dimensional polymer nanosheets prepared using different micelles: SDS (a), F127 (b), and P123 (c) in Example 1. It can be seen that two-dimensional polymer nanosheets were successfully prepared using SDS as the micelle, while those using F127 and P123 as micelles were not. It is speculated that micelle size may affect the polymerization process. The size of SDS micelles, a nonionic surfactant, is much smaller than that of the block copolymers F127 and P123. Therefore, the smaller size of SDS provides more confined space, thereby ensuring precise assembly of the polymer.

[0051] Figure 4 : is a transmission electron micrograph of the SDS micelles prepared in Example 1. It can be seen that the average size of the SDS micelles is between 1-10 nm.

[0052] Figure 5Surface tension diagram of SDS micelles used in Example 1. It can be seen that with the increase of SDS concentration, the surface tension of SDS gradually decreases. When the SDS concentration reaches 300 mM, the solution is saturated.

[0053] Figure 6 The contact angles of 2DPS-NH (a), 2DPS-BA (b), 2DPS-Cl (c), 2DPS-EP (d), 2DPS-SH (e), and PTEOS (f) prepared in Example 1 are shown in the figure. The contact angle of the polymer silicon wafer (PTEOS) prepared from pure TEOS is 27.4°, which shows its hydrophilicity. The contact angle of the 2DPS-NH wafer with amino groups is 25.6°, which is lower than that of PTEOS. This is because the hydrophilic amino groups are located on its surface, which enhances its hydrophilicity. The contact angles of the 2DPS-BA wafer with boron groups, the 2DPS-Cl wafer with chlorine groups, the 2DPS-EP wafer with epoxy bonds, and the 2DPS-SH wafer with thiol groups are 34.6°, 39.6°, 38.9°, and 57°, respectively, which are higher than those of PTEOS. Their groups all have a certain degree of hydrophobicity, which proves that their groups are all located on the surface of the wafer, affecting the original hydrophilicity of PTEOS.

[0054] Figure 7 The infrared spectra of 2DPS-NH (a), 2DPS-BA (b), 2DPS-Cl (c), 2DPS-EP (d), 2DPS-SH (e), and PTEOS (f) prepared in Example 1 are shown in the figure. -1 、1369cm -1 、752cm -1 、2551cm -1 1220~1280cm -1 Several characteristic absorption peaks were generated, indicating that the two-dimensional polymer nanosheet adsorbents were successfully prepared.

[0055] Figure 8 Dynamic light scattering plots of 2DPS-NH (a), 2DPS-BA (b), 2DPS-Cl (c), 2DPS-EP (d), 2DPS-SH (e), and PTEOS (f) prepared in Example 1. The results show that the micelle sizes in all solutions ranged from 1 to 10 nm, consistent with the size observed in transmission electron microscopy. Furthermore, a large number of two-dimensional polymer nanosheets ranging in size from 100 to 1000 nm were present in the 2DPS-NH, 2DPS-Cl, 2DPS-SH, and PTEOS solutions.

[0056] Example 2:

[0057] (1) Preparation of 2DPS-BA:

[0058] First, weigh 5.8g of SDS and prepare a 200mM SDS solution. SDS will form a micelle structure in the solution. Then take 8.0mL of SDS solution, add 12.6mg of 4-VPBA, 12.5μL of TEOS and 20.3mg of APS to the SDS solution, add 0.5μL of ammonia water by ultrasonication to adjust the pH value to 8-9, and let the mixture stand at room temperature for 10h to ensure that the monomer, TEOS and APS fully enter the micelles before polymerization occurs; after the polymerization is completed, use liquid nitrogen to quickly freeze for 10min and polymerize at -20℃ for 72h. Use deionized water at 20℃ to dissolve the polymer nanosheets prepared by the above process, ultrasonicate, centrifuge and filter several times until the filtrate no longer produces foam during the ultrasonication process. Freeze-dry again to obtain two-dimensional polymer nanosheets 2DPS-BA;

[0059] (2) Preparation of 2DPS-NH, 2DPS-Cl, 2DPS-EP, and 2DPS-SH:

[0060] First, weigh 5.8g of SDS and prepare a 200mM SDS solution. SDS will form a micelle structure in the solution. Then take 8.0mL of SDS solution, add 10.0μL APTES and 10.0μL TEOS to the SDS solution, add 0.5μL ammonia water by ultrasonication to adjust the pH value, and let the mixture stand at room temperature for 10h to ensure that APTES and TEOS fully enter the interior of the micelles and then polymerize; after standing, use liquid nitrogen to quickly freeze for 10min, and polymerize at -20℃ for 48h. Use deionized water at 20℃ to dissolve the polymer nanosheets prepared by the above process, ultrasonicate for a period of time, centrifuge and filter, repeat several times until the filtrate no longer produces foam during the ultrasonic process. Freeze-dry again to obtain two-dimensional polymer nanosheets 2DPS-NH;

[0061] (3) The APTES:TEOS=10.0μL:10.0μL in step (2) was changed to CPTES:TEOS=10.0μL:10.0μL, GPTES:TEOS=10.0μL:10.0μL, and MPTES:TEOS=10.0μL:5.0μL, respectively, and the above operation was repeated to obtain two-dimensional polymer nanosheets 2DPS-Cl with chlorine groups, two-dimensional polymer nanosheets 2DPS-EP with epoxy bonds, and two-dimensional polymer nanosheets 2DPS-SH with thiol groups.

[0062] Example 3:

[0063] (1) Preparation of DPS-BA:

[0064] First, weigh 8.6g of SDS and prepare a 300mM SDS solution. SDS will form a micelle structure in the solution. Then take 10.0mL of SDS solution, add 12.6mg of 4-VPBA, 15μLTEOS and 24.3mgAPS to the SDS solution, add 0.5μL of ammonia water by ultrasonication to adjust the pH value to 8-9, and let the mixture stand at room temperature for 11h to ensure that the monomer, TEOS and APS fully enter the micelles before polymerization occurs; after the polymerization reaction is completed, use liquid nitrogen to quickly freeze for 10min, and polymerize at -20℃ for 96h. Use 40℃ deionized water to dissolve the polymer nanosheets prepared by the above process, ultrasonicate, centrifuge and filter several times until the filtrate no longer produces foam during the ultrasonication process. Freeze-dry again to obtain two-dimensional polymer nanosheets 2DPS-BA;

[0065] (2) Preparation of 2DPS-NH, 2DPS-Cl, 2DPS-EP, and 2DPS-SH:

[0066] First, weigh 8.6g of SDS and prepare a 300mM SDS solution. SDS will form a micellar structure in the solution. Then take 10.0mL of SDS solution, add 10.0μL APTES and 20.0μL TEOS to the SDS solution, add 0.5μL ammonia water to adjust the pH value by ultrasonication, and let the mixture stand at room temperature for 11h to ensure that APTES and TEOS fully enter the interior of the micelles before polymerization occurs; after the polymerization is completed, use liquid nitrogen to quickly freeze for 10min, and polymerize at -20℃ for 96h. Use 40℃ deionized water to dissolve the polymer nanosheets prepared by the above process, ultrasonicate, centrifuge and filter several times until the filtrate no longer produces foam during the ultrasonication process. Freeze-dry again to obtain two-dimensional polymer nanosheets 2DPS-NH;

[0067] (3) The APTES:TEOS=10.0μL:20.0μL in step (2) was changed to CPTES:TEOS=10.0μL:20.0μL, GPTES:TEOS=10.0μL:20.0μL, and MPTES:TEOS=10.0μL:15.0μL, respectively, and the above operation was repeated to obtain two-dimensional polymer nanosheets 2DPS-Cl with chlorine groups, two-dimensional polymer nanosheets 2DPS-EP with epoxy bonds, and two-dimensional polymer nanosheets 2DPS-SH with thiol groups.

[0068] Test Example 1:

[0069] 2 mL of adenosine monophosphate (AMP) solution with an initial concentration of 300 μmol / L was added to a centrifuge tube, and 2 mg of the 2DPS-BA adsorbent in Example 1 was added. The adsorbent and solution were separated by centrifugation. The AMP concentration in the filtrate was calculated and measured by ultraviolet spectrophotometry at a wavelength of 259 nm, and the results were obtained. Figure 9 The time to reach adsorption equilibrium was calculated. The results showed that the adsorption capacity of 2DPS-BA increased rapidly during the first 240 minutes, indicating that the adsorbate readily entered the adsorbent. After this rapid adsorption, the adsorption rate began to decline due to a decrease in AMP concentration and the number of binding sites.

[0070] Test Example 2:

[0071] 2 mL of AMP solution with initial concentrations of 30, 60, 100, 150, 300, 500, 700, and 1000 μmol / L was added to a centrifuge tube, and 2 mg of the 2DPS-BA adsorbent in Example 1 was added to each of them. The test solution was placed in a water bath at 15°C, 25°C, and 35°C for 24 h, and then the adsorbent and solution were separated by centrifugation. The concentration of unadsorbed AMP molecules was measured at a wavelength of 259 nm using a UV-visible spectrophotometer, and the results were obtained. Figure 10 The adsorption capacity was calculated. The results showed that at 15°C, the maximum adsorption capacity of 2DPS-BA for AMP was 25.71 μmol / g when adsorption equilibrium was reached; at 25°C, the maximum adsorption capacity of 2DPS-BA for AMP was 30.29 μmol / g when adsorption equilibrium was reached; and at 35°C, the maximum adsorption capacity of 2DPS-BA for AMP was 41.46 μmol / g when adsorption equilibrium was reached.

[0072] Test Example 3:

[0073] Adenosine (A), 2-deoxyadenosine (dA) and adenosine monophosphate (AMP) were selected as selective adsorbents, and solutions of the above three compounds were prepared at a concentration of 300 μmol / L. 2 mL of each solution was added to a centrifuge tube, and 2 mg of the 2DPS-BA adsorbent prepared in Example 1 was added to each solution. The test solution was placed in a constant temperature and humidity chamber at 25°C for 24 hours, and then the adsorbent and the solution were separated by centrifugal filtration. The concentrations of unadsorbed A molecules and dA molecules were measured using a UV-visible spectrophotometer at a wavelength of 259 nm, and the results were obtained. Figure 11The results showed that the adsorption of 2DPS-BA for the three compounds followed the order of AMP>dA>A. Therefore, it can be inferred that 2DPS-BA mainly relies on boron affinity as the main adsorption effect, and therefore has good adsorption specificity for AMP.

[0074] Test Example 4:

[0075] 2.0 mg of adsorbent was added to a centrifuge tube, and then 2.0 mL of AMP solution with an initial concentration of 300 μmol / L was added. After static adsorption for 24 h under water bath shaking conditions, the adsorbent and solution were separated by centrifugation. The unadsorbed AMP molecules were detected by UV-vis at a wavelength of 259 nm, and Q was calculated. e The 2DPS-BA collected after adsorption of AMP was regenerated by soaking it in 10.0 mL of hydrochloric acid solution with pH = 3.3 to obtain the regenerated 2DPS-BA adsorbent. Repeat the above steps five times. The whole process was carried out in two parallel experiments, and the results were obtained. Figure 12 The results showed that after five regeneration cycles, the adsorption capacity of AMP on 2DPS-BA was 82.61% of that in the first cycle. The slight loss may be due to the destruction of some sites on the surface of the nanosheets after five regeneration cycles or the failure of some AMP to be completely eluted.

[0076] Note: The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Therefore, although this specification has described the present invention in detail with reference to the above embodiments, it should be understood by those skilled in the art that the present invention may still be modified or replaced by equivalents. All technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for preparing a two-dimensional polymer nanosheet adsorbent by controllable micelle assembly, characterized in that: The steps include: (1) Preparation of 2DPS-BA: First, an SDS solution is prepared. SDS will form a micelle structure in the solution. Then, the monomer 4VPBA, the crosslinker TEOS, and the initiator APS are added to the SDS solution in proportion. Ammonia water is added by ultrasonication to adjust the pH value to 8-9. The mixture is allowed to stand at room temperature for a period of time to ensure that the monomer, TEOS, and APS fully enter the micelles before polymerization occurs. After the standing period, the mixture is rapidly frozen using liquid nitrogen and polymerized at low temperature. After the polymerization is completed, the mixture is freeze-dried to obtain a two-dimensional polymer nanosheet. The polymer nanosheet prepared by the above process is dissolved in deionized water, ultrasonicated, and centrifuged and filtered several times until the filtrate no longer produces foam during the ultrasonication process. The mixture is then freeze-dried again to obtain a two-dimensional polymer nanosheet 2DPS-BA. (2) Preparation of two-dimensional polymer nanosheets with different functional groups: First, an SDS solution is prepared. SDS will form a micelle structure in the solution. Then, the monomer APTES and the crosslinker TEOS are added to the SDS solution in proportion. Ammonia water is added by ultrasonication to adjust the pH value to 8-9. The mixture is allowed to stand at room temperature for a period of time to ensure that APTES and TEOS fully enter the micelles and then polymerize. After the standing period, liquid nitrogen is used for rapid freezing, low-temperature polymerization is carried out, and freeze-drying is performed after the polymerization is completed to obtain two-dimensional polymer nanosheets. The polymer nanosheets prepared by the above process are dissolved in deionized water, ultrasonicated, and centrifuged and filtered. This process is repeated several times until the filtrate no longer produces foam during the ultrasonication process. The filtrate is then freeze-dried again to obtain two-dimensional polymer nanosheets 2DPS-NH. (3) The APTES in step (2) was replaced with CPTES, GPTES, and MPTES in sequence, and the above operation was repeated to obtain polymer nanosheets 2DPS-Cl with chlorine groups, polymer nanosheets 2DPS-EP with epoxy bonds, and polymer nanosheets 2DPS-SH with thiol groups.

2. The preparation method according to claim 1, characterized in that In step (1), the usage ratio of 4-VPBA, TEOS, APS and SDS is 1.3 mg: 1.0.-1.5μL: 2.0-2.5mg: 0.8-1.0mL, where the concentration of SDS solution is 200-300mM.

3. The preparation method according to claim 1, characterized in that In step (1), the temperature of the low-temperature polymerization is -20°C, and the time of the low-temperature polymerization is 72-120 hours.

4. The preparation method according to claim 1, characterized in that In step (2), the usage ratio of the APTES or CPTES or GPTES or MPTES, TEOS and SDS solution is 1.0 μL:1.0-2.0 μL:0.8-1.0 mL, wherein the concentration of the SDS solution is 200-300 mM.

5. The preparation method according to claim 1, characterized in that In step (2), the temperature of the low-temperature polymerization is -20°C, and the time of the low-temperature polymerization is 48-96 hours.

6. The preparation method according to claim 1, characterized in that In steps (1) and (2), the freeze-drying temperature is -60°C.

7. The preparation method according to claim 1, characterized in that In steps (1) and (2), when deionized water is used to dissolve the prepared polymer nanosheets, the temperature of the deionized water is 20-40°C.

8. The preparation method according to claim 1, characterized in that In steps (1) and (2), the centrifugal speed is 10000 rpm, the stirring time is 3-10 min, and the number of times is 3-5 times.

9. Use of the two-dimensional polymer nanosheet adsorbent 2DPS-BA, 2DPS-NH, 2DPS-Cl, 2DPS-EP or 2DPS-SH prepared by the preparation method according to any one of claims 1 to 8 for selective separation of adenosine monophosphate (AMP).

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