Preparation method and application of hierarchical pore metal organic framework surface molecularly imprinted polymer
By preparing the surface molecular imprinted polymer of multi-stage porous metal organic framework, the problem of removing sertraline hydrochloride in the prior art is solved, efficient adsorption and separation enrichment are achieved, and the reusability and environmental protection performance of the material are significantly improved.
Patent Information
- Application Number
- CN202411324083.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-01-03
AI Technical Summary
The prior art is difficult to effectively remove sertraline hydrochloride residues in the environment, which poses a potential threat to ecosystems and human health, and the microporous structure of traditional metal-organic framework materials limits adsorption rate and capacity.
The preparation method of the surface molecular imprinted polymer of multi-stage porous metal organic framework is used to prepolymerize the functional monomer and template molecule sertraline hydrochloride and the carrier multi-stage porous metal organic framework in deionized water, and add crosslinking agent and initiation. After the agent is heat polymerized, a multi-stage porous metal organic framework surface molecular imprinted polymer with high adsorption capacity was prepared. This material is used to selectively adsorption and separation enriched sertraline hydrochloride, and to achieve regeneration and recycling of the material by methanol elution.
It has achieved efficient selective adsorption and separation enrichment of sertraline hydrochloride, with a recovery rate of more than 90%, and maintained adsorption performance in multiple reuses, which significantly reduced the residue of sertraline hydrochloride in the natural environment and improved the Reusability and environmental protection of materials.
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Figure CN119241768A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of preparation of functional high molecular polymers and adsorption and removal of sertraline hydrochloride, and specifically relates to a preparation method and application of a molecularly imprinted polymer on the surface of a multi-level porous metal organic framework. Background Art
[0002] Sertraline hydrochloride is a commonly used selective serotonin reuptake inhibitor (SSRI), mainly used to treat mental illnesses such as depression and anxiety. However, due to the widespread use of sertraline hydrochloride, its residue in the environment poses a potential threat to the ecosystem and human health. Existing wastewater treatment technologies are difficult to completely remove this drug residue, causing it to enter water bodies and soil, which may cause abnormal behavioral and physiological effects on aquatic organisms and spread through the ecological chain, posing hidden risks to human health. Therefore, it is necessary to develop methods to efficiently remove sertraline hydrochloride from the environment and reduce its residue in the natural environment to maintain the health of the ecosystem and the safety of the public.
[0003] Molecularly imprinted polymers (MIPs) are highly cross-linked complexes formed by template molecules and functional monomers. After the template molecules are removed, the spatial structure, size and specific recognition sites of functional groups in the MIPs are highly matched with the template molecules. This "memory" function enables MIPs to selectively adsorb and recognize target template molecules in the presence of other compounds. Compared with traditional molecularly imprinted polymers, the recognition sites of surface molecularly imprinted polymers are located on the surface of the material and can directly contact the target molecules, thus having a faster adsorption rate and a shorter equilibrium adsorption time. In addition, the target molecules are more easily eluted after adsorption, thereby achieving material regeneration. This regeneration performance gives surface molecularly imprinted polymers a longer service life and higher reusability.
[0004] Metal organic frameworks (MOFs) have significant advantages such as controlled release, regeneration performance, and excellent chemical and thermal stability due to their unique porous structure, high specific surface area, tunability, and diversity. These characteristics make MOFs an ideal carrier for constructing efficient, selective, and controllable surface molecular imprinting polymers. However, the pore size of traditional MOFs is usually less than 2nm, which belongs to a microporous structure. This limits the improvement of reaction rate and adsorption capacity during the adsorption process to a certain extent, thereby reducing its potential in a wide range of applications. Summary of the invention
[0005] The technical problem solved by the present invention is to provide a method for preparing a molecularly imprinted polymer on the surface of a multi-level porous metal organic framework. The molecularly imprinted polymer on the surface of a multi-level porous metal organic framework prepared by the method has a strong ability to selectively adsorb the target compound sertraline hydrochloride in an aqueous solution and a high adsorption amount, and can be used for the separation and enrichment of sertraline hydrochloride in actual environmental samples.
[0006] The present invention adopts the following technical scheme to solve the above technical problems. A method for preparing a molecularly imprinted polymer on the surface of a multi-level porous metal organic framework is characterized in that the specific steps are: dispersing a functional monomer methacrylic acid and a template molecule sertraline hydrochloride into deionized water containing a carrier multi-level porous metal organic framework, prepolymerizing at 20-40°C for 2-8h, adding a crosslinking agent ethylene glycol dimethacrylate and an initiator azobisisobutyronitrile, and after ultrasonic and nitrogen protection, thermally polymerizing at 50-70°C for 20-30h, eluting and drying to obtain a molecularly imprinted polymer on the surface of the multi-level porous metal organic framework, wherein the specific preparation process of the carrier multi-level porous metal organic framework is: mixing a soft template and zinc nitrate hexahydrate and adding them to a dimethylimidazole solution, and then reacting at 20-40°C for 2-6h to obtain a multi-level porous metal organic framework, wherein the soft template is one or more of dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide or octadecyltrimethylammonium bromide.
[0007] It is further defined that the molar ratio of the template molecule, the functional monomer and the cross-linking agent is 0.3-1.5:2-4:10-20.
[0008] It is further defined that the molar ratio of the soft template to zinc nitrate hexahydrate is 0.1-1.5:1.
[0009] It is further defined that the elution process uses the Soxhlet extraction method, and the specific process is to use a mixture of methanol and acetic acid in a volume ratio of 9:1 for Soxhlet extraction for 48 hours.
[0010] The multi-level porous metal organic framework surface molecular imprinted polymer of the present invention is used for the selective separation and enrichment of sertraline hydrochloride in actual environmental samples. The specific process is: placing the multi-level porous metal organic framework surface molecular imprinted polymer in the actual environmental sample containing sertraline hydrochloride to achieve selective adsorption of sertraline hydrochloride, and then using methanol as an elution solvent to achieve separation and enrichment of sertraline hydrochloride and regeneration and recycling of the multi-level porous metal organic framework surface molecular imprinted polymer.
[0011] It is further defined that the molecular imprinting polymer on the surface of the multi-level porous metal organic framework is filled in a polypropylene solid phase extraction column equipped with a sieve plate to achieve the pretreatment of sertraline hydrochloride in actual environmental water samples. The results of the spiked experiment show that the recovery rate of sertraline hydrochloride reaches more than 90%, indicating that the molecular imprinting polymer on the surface of the multi-level porous metal organic framework can be used for the separation and enrichment of sertraline hydrochloride; after repeated use for more than 10 times, the adsorption performance of the solid phase extraction column has no obvious decrease, indicating that the molecular imprinting polymer on the surface of the multi-level porous metal organic framework can be regenerated and recycled.
[0012] The multi-level porous metal organic framework surface molecular imprinting polymer of the present invention is used for selectively removing sertraline hydrochloride in actual environmental samples. The multi-level porous metal organic framework surface molecular imprinting polymer can selectively adsorb sertraline hydrochloride in an aqueous solution containing sertraline hydrochloride, rotigotine, carbamazepine, citalopram, venlafaxine, fluoxetine, dioctyl phthalate and aspartame.
[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The present invention provides a multi-level porous organic framework metal material prepared by using a variety of surfactants as a carrier for preparing a sertraline hydrochloride surface imprinted polymer. The prepared multi-level porous metal organic framework surface imprinted polymer has the properties of uniform particle size distribution, large adsorption capacity, strong affinity in water, etc.
[0014] 2. The preparation process of the present invention uses deionized water as the reaction solvent, which reduces the secondary pollution of the organic solvent to the environment on the one hand, and improves the adsorption capacity of the imprinted polymer on the other hand. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a synthetic route map of the multi-level porous metal organic framework in the present invention.
[0016] Figure 2 It is a synthetic route map of the imprinted polymer in the present invention.
[0017] Figure 3 This is a diagram of the adsorption kinetics of the imprinted polymer and the non-imprinted polymer in Example 1 of the present invention.
[0018] Figure 4 It is the adsorption isotherm diagram of the imprinted polymer and the non-imprinted polymer in Example 1 of the present invention.
[0019] Figure 5 This is a graph showing the competitive adsorption capacity of the imprinted polymer and the non-imprinted polymer on different substrates in a mixed solution in Example 1 of the present invention.
[0020] Figure 6The invention discloses an effect of different types of eluents on the elution effect of sertraline hydrochloride when the imprinted polymer in Example 1 of the present invention is used as a solid phase extraction column filler, wherein 1-acetonitrile, 2-acetonitrile / water mixture (volume ratio 60 / 40), 3-methanol / water mixture (volume ratio 80 / 20), 4-methanol / water / acetic acid mixture (volume ratio 80 / 19 / 1), 5-methanol / water / acetic acid mixture (volume ratio 80 / 18 / 2), 6-methanol. DETAILED DESCRIPTION
[0021] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention. Example 1
[0022] Preparation of a hierarchical porous metal-organic framework: Hexadecyltrimethylammonium bromide and zinc nitrate hexahydrate were mixed in a molar ratio of 1:1 and added to dimethylimidazole, followed by reaction at 25° C. for 3 h to obtain a hierarchical porous metal-organic framework.
[0023] Preparation of imprinted polymer: 34 μL (0.4 mmol) of methacrylic acid (functional monomer), 0.08 g of the above-prepared hierarchical porous metal organic framework (support) and 0.03 g of sertraline hydrochloride (template molecule) were prepolymerized at 30 °C for 4 h using 30 mL of deionized water as solvent, and then 226 μL (1.2 mmol) of crosslinker ethylene glycol dimethacrylate (EDMA) and 50 mg of initiator 2,2-azobisisobutyronitrile (AIBN) were added. After ultrasonic and nitrogen protection, the product was thermally initiated and polymerized at 60 °C for 24 h. The product was then extracted with a methanol / acetic acid mixture with a volume ratio of 9:1 for 48 h and then vacuum dried to obtain the imprinted polymer, named MIP@HP-ZIIF-8. The non-molecular imprinted polymer (NIPs) was prepared in the same manner as above except that the template molecule was not added, and was named NIP@HP-ZIF-8. Example 2
[0024] Preparation of a hierarchical porous metal-organic framework: dodecyltrimethylammonium bromide and zinc nitrate hexahydrate were mixed in a molar ratio of 1:1 and added to dimethylimidazole, followed by reaction at 25° C. for 3 h to obtain a hierarchical porous metal-organic framework.
[0025] Preparation of imprinted polymer: 34 μL (0.4 mmol) of methacrylic acid (functional monomer), 0.08 g of the above-prepared hierarchical porous metal organic framework (support) and 0.03 g of sertraline hydrochloride (template molecule) were prepolymerized at 30 °C for 4 h using 30 mL of deionized water as solvent, and then 226 μL (1.2 mmol) of crosslinker ethylene glycol dimethacrylate (EDMA) and 50 mg of initiator 2,2-azobisisobutyronitrile (AIBN) were added. After ultrasonic and nitrogen protection, the product was thermally initiated and polymerized at 60 °C for 24 h. The product was then extracted with a methanol / acetic acid mixture with a volume ratio of 9:1 for 48 h and then vacuum dried to obtain the imprinted polymer, named MIP@HP-ZIIF-8. The non-molecular imprinted polymer (NIPs) was prepared in the same manner as above except that the template molecule was not added, and was named NIP@HP-ZIF-8. Example 3
[0026] Preparation of a hierarchical porous metal organic framework: Tetradecyltrimethylammonium bromide and zinc nitrate hexahydrate were mixed in a molar ratio of 1:1 and added to dimethylimidazole, followed by reaction at 25° C. for 3 h to obtain a hierarchical porous metal organic framework.
[0027] Preparation of imprinted polymer: 34 μL (0.4 mmol) of methacrylic acid (functional monomer), 0.08 g of the above-prepared hierarchical porous metal organic framework (support) and 0.03 g of sertraline hydrochloride (template molecule) were prepolymerized at 30 °C for 4 h using 30 mL of deionized water as solvent, and then 226 μL (1.2 mmol) of crosslinker ethylene glycol dimethacrylate (EDMA) and 50 mg of initiator 2,2-azobisisobutyronitrile (AIBN) were added. After ultrasonic and nitrogen protection, the product was thermally initiated and polymerized at 60 °C for 24 h. The product was then extracted with a methanol / acetic acid mixture with a volume ratio of 9:1 for 48 h and then vacuum dried to obtain the imprinted polymer, named MIP@HP-ZIIF-8. The non-molecular imprinted polymer (NIPs) was prepared in the same manner as above except that the template molecule was not added, and was named NIP@HP-ZIF-8. Example 4
[0028] Preparation of a hierarchical porous metal-organic framework: Octadecyltrimethylammonium bromide and zinc nitrate hexahydrate were mixed in a molar ratio of 1:1 and added to dimethylimidazole, followed by reaction at 25° C. for 3 h to obtain a hierarchical porous metal-organic framework.
[0029] Preparation of imprinted polymer: 34 μL (0.4 mmol) of methacrylic acid (functional monomer), 0.08 g of the above-prepared hierarchical porous metal organic framework (support) and 0.03 g of sertraline hydrochloride (template molecule) were prepolymerized at 30 °C for 4 h using 30 mL of deionized water as solvent, and then 226 μL (1.2 mmol) of crosslinker ethylene glycol dimethacrylate (EDMA) and 50 mg of initiator 2,2-azobisisobutyronitrile (AIBN) were added. After ultrasonic and nitrogen protection, the product was thermally initiated and polymerized at 60 °C for 24 h. The product was then extracted with a methanol / acetic acid mixture with a volume ratio of 9:1 for 48 h and then vacuum dried to obtain the imprinted polymer, named MIP@HP-ZIIF-8. The non-molecular imprinted polymer (NIPs) was prepared in the same manner as above except that the template molecule was not added, and was named NIP@HP-ZIF-8. Example 5
[0030] Preparation of a hierarchical porous metal organic framework: Hexadecyltrimethylammonium bromide and zinc nitrate hexahydrate were mixed in a molar ratio of 0.1:1, added to dimethylimidazole, and reacted at 25° C. for 3 h to obtain a hierarchical porous metal organic framework.
[0031] Preparation of imprinted polymer: 34 μL (0.4 mmol) of methacrylic acid (functional monomer), 0.08 g of the above-prepared hierarchical porous metal organic framework (support) and 0.03 g of sertraline hydrochloride (template molecule) were prepolymerized at 30 °C for 4 h using 30 mL of deionized water as solvent, and then 226 μL (1.2 mmol) of crosslinker ethylene glycol dimethacrylate (EDMA) and 50 mg of initiator 2,2-azobisisobutyronitrile (AIBN) were added. After ultrasonic and nitrogen protection, the product was thermally initiated and polymerized at 60 °C for 24 h. The product was then extracted with a methanol / acetic acid mixture with a volume ratio of 9:1 for 48 h and then vacuum dried to obtain the imprinted polymer, named MIP@HP-ZIIF-8. The non-molecular imprinted polymer (NIPs) was prepared in the same manner as above except that the template molecule was not added, and was named NIP@HP-ZIF-8. Example 6
[0032] Preparation of a hierarchical porous metal organic framework: Hexadecyltrimethylammonium bromide and zinc nitrate hexahydrate were mixed in a molar ratio of 0.25:1, added to dimethylimidazole, and reacted at 25° C. for 3 h to obtain a hierarchical porous metal organic framework.
[0033] Preparation of imprinted polymer: 34 μL (0.4 mmol) of methacrylic acid (functional monomer), 0.08 g of the above-prepared hierarchical porous metal organic framework (support) and 0.03 g of sertraline hydrochloride (template molecule) were prepolymerized at 30 °C for 4 h using 30 mL of deionized water as solvent, and then 226 μL (1.2 mmol) of crosslinker ethylene glycol dimethacrylate (EDMA) and 50 mg of initiator 2,2-azobisisobutyronitrile (AIBN) were added. After ultrasonic and nitrogen protection, the product was thermally initiated and polymerized at 60 °C for 24 h. The product was then extracted with a methanol / acetic acid mixture with a volume ratio of 9:1 for 48 h and then vacuum dried to obtain the imprinted polymer, named MIP@HP-ZIIF-8. The non-molecular imprinted polymer (NIPs) was prepared in the same manner as above except that the template molecule was not added, and was named NIP@HP-ZIF-8. Example 7
[0034] 10 mg of MIP@HP-ZIF-8 and NIP@HP-ZIF-8 prepared in Example 1 were mixed with 10 mL of 50 mg L -1 The mixture was mixed with sertraline hydrochloride aqueous solution, and after oscillation at room temperature for a certain period of time (0-180 min), the supernatant was taken and the absorbance value at 274 nm was measured by UV spectrophotometer. The results were as follows: Figure 3 shown. Example 8
[0035] At different temperatures (25°C, 35°C, 45°C), 10 mg of MIP@HP-ZIF-8 and NIP@HP-ZIF-8 prepared in Example 1 were mixed with 10 mL of sertraline hydrochloride aqueous solution (0-400 mg L -1 ), after 3 h of oscillation adsorption at room temperature, the supernatant was taken and the absorbance value at 274 nm was measured by UV spectrophotometer. The results were as follows Figure 4 shown. Example 9
[0036] 5 mg of MIP@HP-ZIF-8 and NIP@HP-ZIF-8 prepared in Example 1 were added into 10 mL of 50 mg L -1 The aqueous solution of sertraline hydrochloride, rotigotine, carbamazepine, citalopram, venlafaxine, fluoxetine, dioctyl phthalate and aspartame was adsorbed at room temperature for 3 hours, and the supernatant was taken to detect the absorbance value at 274nm with an ultraviolet spectrophotometer. The results are as follows Figure 5 The polymer MIP@HP-ZIF-8 has good competitive selective recognition performance for sertraline hydrochloride, which shows that the polymer MIP@HP-ZIF-8 still has a very good adsorption effect on sertraline hydrochloride under complex conditions close to the actual situation, which is of great significance for its application in the removal of sertraline hydrochloride in actual water samples. Example 10
[0037] 30 mg of MIP@HP-ZIIF-8 prepared in Example 1 was loaded into a 3 mL polypropylene column to prepare a solid phase extraction microcolumn. -1 The sertraline hydrochloride aqueous solution was passed through a solid phase extraction column and eluted with 2 mL of acetonitrile. After elution, the content of sertraline hydrochloride in the eluate was detected by HPLC. This method was also used to optimize the type of elution solvent. The results are as follows Figure 6 shown.
[0038] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.
Claims
1. A method for preparing a molecularly imprinted polymer on the surface of a multi-level porous metal organic framework, characterized in that The specific steps are as follows: functional monomer methacrylic acid and template molecule sertraline hydrochloride are dispersed in deionized water containing a carrier multi-level porous metal organic framework, prepolymerized at 20-40°C for 2-8h, then crosslinking agent ethylene glycol dimethacrylate and initiator azobisisobutyronitrile are added, after ultrasonic and nitrogen protection, thermally polymerized at 50-70°C for 20-30h, eluted and dried to obtain a molecular imprinting polymer on the surface of the multi-level porous metal organic framework, wherein the specific preparation process of the carrier multi-level porous metal organic framework is: a soft template and zinc nitrate hexahydrate are mixed and added to a dimethylimidazole solution, and then reacted at 20-40°C for 2-6h to obtain a multi-level porous metal organic framework, wherein the soft template is one or more of dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide or octadecyltrimethylammonium bromide.
2. The method for preparing a molecularly imprinted polymer on the surface of a multi-level porous metal organic framework according to claim 1, characterized in that: The molar ratio of the template molecule, the functional monomer and the cross-linking agent is 0.3-1.5:2-4:10-20.
3. The method for preparing a molecularly imprinted polymer on the surface of a multi-level porous metal organic framework according to claim 1, characterized in that: The molar ratio of the soft template to zinc nitrate hexahydrate is 0.1-1.5:
1.
4. The method for preparing a molecularly imprinted polymer on the surface of a multi-level porous metal organic framework according to claim 1, characterized in that: The elution process uses the Soxhlet extraction method, and the specific process is to use a mixed solution of methanol and acetic acid in a volume ratio of 9:1 for Soxhlet extraction for 48 hours.
5. The multi-level porous metal organic framework surface molecular imprinted polymer prepared by the method according to any one of claims 1 to 4 is used for the selective separation and enrichment of sertraline hydrochloride in actual environmental samples.
6. The use according to claim 5, characterized in that The specific process is: placing the molecular imprinting polymer on the surface of the hierarchical porous metal-organic framework in an actual environmental sample containing sertraline hydrochloride to achieve selective adsorption of sertraline hydrochloride, and then using methanol as an elution solvent to achieve the separation and enrichment of sertraline hydrochloride and the regeneration and recycling of the molecular imprinting polymer on the surface of the hierarchical porous metal-organic framework.
7. The use according to claim 5, characterized in that: The molecular imprinting polymer on the surface of the multi-level porous metal-organic framework was filled in a polypropylene solid phase extraction column equipped with a sieve plate to achieve the pretreatment of sertraline hydrochloride in actual environmental water samples. The results of the spiked experiment showed that the recovery rate of sertraline hydrochloride reached more than 90%, indicating that the molecular imprinting polymer on the surface of the multi-level porous metal-organic framework can be used for the separation and enrichment of sertraline hydrochloride; after repeated use for more than 10 times, the adsorption performance of the solid phase extraction column did not decrease significantly, indicating that the molecular imprinting polymer on the surface of the multi-level porous metal-organic framework can be regenerated and recycled.
8. The multi-level porous metal organic framework surface molecular imprinted polymer prepared according to the method described in any one of claims 1 to 4 is used to selectively remove sertraline hydrochloride from actual environmental samples, and the multi-level porous metal organic framework surface molecular imprinted polymer can selectively adsorb sertraline hydrochloride in an aqueous solution containing sertraline hydrochloride, rotigotine, carbamazepine, citalopram, venlafaxine, fluoxetine, dioctyl phthalate and aspartame.