Preparation method and application of a solid supported deep eutectic solvent material

Abstract

This invention discloses a method for preparing and applying a solid-supported eutectic solvent material. The specific preparation process involves: firstly, chemically bonding a hydrogen bond acceptor derivative, N,N-dimethylethanolamine, onto the surface of a chloromethyl polystyrene resin support to generate a hydrogen bond acceptor structure in situ; then, thoroughly mixing this structure with a corresponding hydrogen bond donor, urea, to finally obtain the chloromethyl polystyrene resin-supported eutectic solvent material. The solid-supported eutectic solvent material provided by this invention combines the advantages of eutectic solvents and solid supports, overcoming the drawbacks of eutectic solvents such as easy loss during use, large dosage, and poor physical stability. It features a simple synthesis method, fast adsorption rate, and large adsorption capacity, and can be used for the efficient adsorption and removal of indomethacin sodium from water.

Description

Technical Field

[0001] This invention belongs to the field of preparation of novel adsorbent materials and adsorption and removal technology of sodium indomethacin in water, specifically relating to a method for preparing and applying a solid-supported eutectic solvent material. Background Technology

[0002] Indomethacin sodium is a water-soluble antipyretic, analgesic, and nonsteroidal anti-inflammatory drug (NSAID) developed based on indomethacin. It is commonly used to treat various ailments, including fever, headache, and arthritis. This drug is not completely absorbed and metabolized by the human body, and because conventional municipal wastewater treatment plants have limited effectiveness in removing this type of pollutant, indomethacin sodium is frequently detected in drinking water and surface water. It not only has harmful effects on aquatic life but also poses risks to humans, including gastrointestinal ulcers, heart failure, cardiovascular and renal adverse reactions. Therefore, how to efficiently remove indomethacin sodium from water bodies has become a major concern for environmental protection and public health.

[0003] Currently, the main methods for removing indomethacin sodium both domestically and internationally include advanced oxidation, membrane filtration, and adsorption. Among these, adsorption is one of the most effective and simplest methods for removing indomethacin. Therefore, designing and preparing more efficient and economical sustainable adsorbents has become an inevitable trend in solving the key constraints on indomethacin sodium removal.

[0004] In recent years, deep eutectic solvents (DESs) have attracted widespread attention as a new type of sustainable green solvent discovered after ionic liquids. They are eutectic mixtures formed by two or more compounds that act as hydrogen bond acceptors and hydrogen bond donors, respectively, through mutual hydrogen bonding. They generally exist as stable liquids at room temperature. Besides possessing excellent properties similar to ionic liquids, such as low vapor pressure, good solubility, strong extraction ability, and good thermal and chemical stability, DESs have simpler preparation processes, lower costs than ionic liquids, and are biodegradable, generally less toxic, and more environmentally friendly. These unique physicochemical properties of DESs also make them exhibit excellent performance in the separation of indomethacin sodium. However, when used directly as reaction media or solvents, they are consumed in large quantities, easily lost, and difficult to separate and recover, thus hindering the large-scale application of DESs. By immobilizing eutectic solvents onto solid supports, we obtain immobilized eutectic solvent materials or solid materials with eutectic solvent structures on their surfaces. This not only preserves the characteristics of eutectic solvents, significantly reduces the amount of eutectic solvent used, and prevents its loss, but also combines the advantages of the support to accelerate mass transfer and simplify the separation process, thereby solving the problems of eutectic solvents in applications.

[0005] This invention employs a chemical bonding method to graft hydrogen bond acceptor derivatives onto the surface of chloromethyl polystyrene resin to generate hydrogen bond acceptor structures in situ. Then, based on the structure and properties of the immobilized hydrogen bond acceptors, corresponding hydrogen bond donors are screened to design and synthesize a novel material for surface-immobilized eutectic solvents. This material is then used for the efficient adsorption and removal of indomethacin sodium in water, providing new ideas and scientific basis for the design, preparation, and efficient separation of indomethacin sodium from immobilized eutectic solvent materials.

[0006] To date, there is only one report in the literature on the adsorption and removal of indomethacin sodium, and the adsorption material used is a metal-organic framework that is not related to eutectic solvents. There are no reports on the use of immobilized eutectic solvent materials for the removal of indomethacin sodium, and no patent literature related to the adsorption and separation of indomethacin sodium and immobilized eutectic solvents has been found.

[0007] The invention disclosed in CN114425304A is a molecular sieve-supported eutectic solvent material, its preparation, and its application. The preparation process uses a surface-functionalized molecular sieve as a carrier, immobilizing a eutectic solvent on its surface to prepare a molecular sieve-supported eutectic solvent material, which is then used as an adsorbent for the separation of aromatics. The eutectic solvent immobilized in this technical solution differs from that of the present invention and needs to be synthesized separately before being mixed with the carrier for physical impregnation, rather than chemically bonding hydrogen bond acceptors to the carrier surface during the immobilization process to generate the immobilized eutectic solvent in situ. The synthesis process, mechanism, and the structure and application of the final product all differ from those of the present invention.

[0008] Similar patent literature includes invention publication number CN106268810A, which discloses a surface-composite modified particulate aggregate carrier material, its preparation method, and its application. The preparation process includes: preparation of Fe3O4 (Fe3O4 oxide), preparation of Fe3O4 particles coated with SiO2, preparation of a eutectic solvent, and mixing the eutectic solvent with the SiO2-coated Fe3O4 particles using ultrasonication. The final product is a surface-composite modified particulate aggregate carrier material used in the biomedical and catalyst fields. The synthesis of this material requires multiple steps, making the process relatively complex. Furthermore, the immobilization method, principle, and the structure and application of the final product differ from those of this invention.

[0009] The invention disclosed in CN107233871B is a chloromethyl polystyrene resin-supported 1-aminoethyl-3-methylimidazolium bromide solid-phase extractant, its preparation method, and its application. This solid-phase extractant is prepared by chemically grafting 1-aminoethyl-3-methylimidazolium bromide ionic liquid onto the surface of chloromethyl polystyrene resin and can be used to separate, enrich, and remove p-nitrophenol from samples. The material in this patent document is a supported ionic liquid material, which does not fall under the category of eutectic solvents. Furthermore, this patent technology only discusses the material's effect on the separation and enrichment of p-nitrophenol and does not mention its application in removing indomethacin sodium.

[0010] As can be seen from the above, existing immobilized eutectic solvent materials involve first synthesizing the eutectic solvent during the immobilization process, then mixing it with the support and fixing it onto the support through physical methods such as coating or impregnation. The hydrogen bond donors or acceptors are not connected to the support through a more stable chemical bond. While immobilized eutectic solvents prepared by physical methods overcome some of the drawbacks of eutectic solvents, such as large consumption, easy loss, and difficulty in separation and recovery during use, they still suffer from poor stability. Summary of the Invention

[0011] The technical problem solved by this invention is to provide a method for preparing and applying a supported eutectic solvent material. This supported eutectic solvent material combines the advantages of eutectic solvents and solid supports, overcoming the defects of eutectic solvents such as easy loss during use, large consumption, and poor physical stability. The supported eutectic solvent material prepared by this method exhibits good adsorption effect in the separation and removal of indomethacin sodium, with a maximum adsorption capacity of up to 1552.6 mg / g. Furthermore, it features a fast adsorption rate, simple operation, and mild usage conditions.

[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for preparing a supported eutectic solvent material, characterized in that the specific process is as follows: a hydrogen bond acceptor structure is generated in situ on the support surface by utilizing the condensation reaction between the active groups on the surface of a chloromethyl polystyrene resin support and the hydrogen bond acceptor derivative N,N-dimethylethanolamine; then, this structure is mixed with the corresponding hydrogen bond donor urea, allowing the hydrogen bond acceptor and hydrogen bond donor to fully interact until the hydrogen bond donor is completely integrated with the hydrogen bond acceptor supported on the support, ultimately obtaining a chloromethyl polystyrene resin supported eutectic solvent material, the structural formula of which is:

[0013]

[0014] The preparation method of the solid-supported eutectic solvent material of the present invention is characterized by the following steps: chloromethyl styrene resin is added to N-methylpyrrolidone for swelling for 6-20 hours, then N,N-dimethylethanolamine is added, and the mixture is reacted at 70-99°C for 4-24 hours. After the reaction is completed, the mixture is cooled to room temperature, and the solid product is thoroughly washed with deionized water. The washed solid product is then vacuum dried at 40-60°C for 12-24 hours to obtain solid-supported choline chloride. The solid-supported choline chloride is then mixed evenly with urea to finally obtain the chloromethyl polystyrene resin solid-supported eutectic solvent material.

[0015] Further specified, the molar ratio of the chloromethyl polystyrene resin to N,N-dimethylethanolamine is 1:1 to 1:10, and the molar ratio of the supported choline chloride to urea is 3:1 to 1:3.

[0016] The method for preparing the supported eutectic solvent material of the present invention is characterized by the following reaction equation during the preparation process:

[0017]

[0018] The application of the supported eutectic solvent material in the adsorption and separation of indomethacin sodium according to the present invention is characterized by the following process: 10 mg of the supported eutectic solvent material is added to 10 mL of indomethacin sodium solution with pH = 5.5-6.5 (0.2-1000 mg / L), and then the solution is kept at a constant temperature of 10-45℃ and shaken for 30-120 min to reach adsorption equilibrium. After the reaction is completed, the removal rate of indomethacin sodium in the solution reaches more than 97%.

[0019] Further, 10 mg of the immobilized eutectic solvent material was added to 10 mL of 0.2-200 mg / L indomethacin sodium solution with pH=6, and then the solution was kept at 30-40℃ and shaken for 30-40 min to reach adsorption equilibrium. After the reaction, the removal rate of indomethacin sodium in the solution reached more than 99%.

[0020] The principle behind the efficient removal of sodium indomethacin using the supported eutectic solvent material of this invention is as follows: sodium indomethacin hydrolyzes in water to form large anions. It exists in the form of [a specific substance], which readily attracts the cations on the hydrogen bond acceptor. Meanwhile, the functional groups such as amino and carbonyl groups on the hydrogen bond donor enhance its binding with sodium indomethacin through hydrogen bonding, thereby achieving the effect of efficiently removing sodium indomethacin.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects: The solid-supported eutectic solvent material prepared by the present invention has the advantages of simple synthesis method, effective prevention of loss of eutectic solvent during application, easy separation and recovery, significant reduction of eutectic solvent usage, and thus greatly reduced cost. Moreover, it has a large adsorption capacity and fast reaction rate, and can quickly and efficiently adsorb, separate and remove sodium indomethacin from water. Attached Figure Description

[0022] Figure 1 The curve shows the effect of reaction time on the adsorption of sodium indomethacin by the supported eutectic solvent material.

[0023] Figure 2 This is the adsorption isotherm of sodium indomethacin for a solid-supported eutectic solvent material.

[0024] Figure 3 The removal rate of sodium indomethacin at different initial concentrations is represented by a solid-supported eutectic solvent material. Detailed Implementation

[0025] The following examples further illustrate the above-described content of the present invention, but it should not be construed as limiting the scope of the subject matter of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention.

[0026] Example 1

[0027] 0.5 g of chloromethyl polystyrene resin was weighed and added to 10 mL of N-methylpyrrolidone for swelling for 6 h. Then, 1.66 g of N,N-dimethylethanolamine was added (molar ratio of chloromethyl polystyrene resin to N,N-dimethylethanolamine 1:10). The mixture was sealed and placed in a 90 °C water bath for 8 h. After the reaction was completed, it was cooled to room temperature, and the solid product was thoroughly washed with deionized water and dried under vacuum at 60 °C for 12 h to obtain solid hydrogen bond acceptor chloromethyl polystyrene resin immobilized with choline chloride. The obtained immobilized hydrogen bond acceptor was then milled and mixed with 0.22 g of hydrogen bond donor urea (molar ratio of immobilized hydrogen bond acceptor choline chloride to hydrogen bond donor urea 1:2) until the two were integrated, and finally, the product was obtained as an immobilized eutectic solvent material.

[0028] 10 mg of the above-prepared immobilized eutectic solvent material was added to 10 mL of indomethacin sodium solution (pH approximately 6) at concentrations of 10 mg / L, 20 mg / L, and 50 mg / L (10 samples per concentration). The solution was incubated at 25°C with shaking for a specified time. Samples were taken at reaction times of 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 40 min, 60 min, 90 min, and 120 min to determine their concentration. The relationship between adsorption capacity and time is shown below. Figure 1As shown in the figure, the adsorption rate gradually levels off with time, reaching adsorption equilibrium within 30 minutes.

[0029] 10 mg of the above-prepared immobilized eutectic solvent material was added to 10 mL of indomethacin sodium solution of different concentrations (0.2-2000 mg / L) (solution pH around 6), and the solution was kept at 25 °C with shaking for 2 h. The adsorption isotherms and removal rates in the concentration range of 0.2-1000 mg / L were as follows: Figure 2 and Figure 3 As shown in the figure, the adsorption capacity of the supported eutectic solvent material for indomethacin sodium increases with the increase of the sodium solution concentration. When the initial concentration is 2000 mg / L, the adsorption capacity of the supported eutectic solvent material for indomethacin sodium can reach 1552.6 mg / g, and the removal rate of the supported eutectic solvent material for indomethacin sodium remains above 97% within the concentration range of 0.2-1000 mg / L.

[0030] Example 2

[0031] 2g of chloromethyl polystyrene resin was weighed and added to 35mL of N-methylpyrrolidone for swelling for 12h. Then, 2g of N,N-dimethylethanolamine was added (the molar ratio of chloromethyl polystyrene resin to N,N-dimethylethanolamine was 1:3). The mixture was sealed and placed in a 95℃ water bath for 16h. After the reaction was completed, it was cooled to room temperature, and the solid product was thoroughly washed with deionized water and dried under vacuum at 45℃ for 24h to obtain solid hydrogen bond acceptor chloromethyl polystyrene resin immobilized with choline chloride. Then, the obtained immobilized hydrogen bond acceptor and 0.45g of urea were placed in a 50℃ water bath and stirred and mixed (the molar ratio of immobilized hydrogen bond acceptor choline chloride to hydrogen bond donor urea was 1:1) until the two were integrated, and finally, the product was obtained as an immobilized eutectic solvent material.

[0032] 10 mg of the above-prepared immobilized eutectic solvent material was added to 10 mL of 0.2-200 mg / L indomethacin sodium solution (pH around 6), and reacted at 40 °C for 1 h. The removal rate of indomethacin sodium was above 99%.

[0033] Example 3

[0034] 1 g of chloromethyl polystyrene resin was weighed and added to 20 mL of N-methylpyrrolidone for swelling for 8 h. Then, 2 g of N,N-dimethylethanolamine was added (the molar ratio of chloromethyl polystyrene resin to N,N-dimethylethanolamine was 1:5). The mixture was sealed and placed in an 85°C water bath for 12 h. After the reaction was completed, it was cooled to room temperature, and the solid product was thoroughly washed with deionized water and dried under vacuum at 50°C for 16 h to obtain solid hydrogen bond acceptor chloromethyl polystyrene resin immobilized with choline chloride. Then, the obtained immobilized hydrogen bond acceptor and 0.11 g of urea were placed in a 45°C water bath for ultrasonic mixing (the molar ratio of immobilized hydrogen bond acceptor choline chloride to hydrogen bond donor urea was 2:1) until the two were integrated, and finally, the product was obtained as an immobilized eutectic solvent material.

[0035] 10 mg of the above-prepared immobilized eutectic solvent material was added to 10 mL of 0.2-200 mg / L sodium indomethacin solution (pH around 6), and reacted at 30 °C for 1 h. The removal rate of sodium indomethacin was above 99%.

[0036] 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 embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the scope of the principles of the present invention, and all such changes and modifications fall within the protection scope of the present invention.

Claims

1. A method for the adsorptive separation of indometacin sodium based on immobilized deep eutectic solvent material, characterized by The specific process is: 10 mg of the solid supported deep eutectic solvent material is added to 10 mL of a 0.2-200 mg / L pH=6 indometacin sodium solution, and then constant temperature oscillation is carried out at 30-40 DEG C for 30-40 min to reach adsorption equilibrium, and the removal rate of indometacin sodium in the solution after the reaction is completed is more than 99%. The specific preparation process of the solid supported deep eutectic solvent material is: the condensation reaction between the active groups on the surface of the chloromethyl polystyrene resin carrier and the hydrogen bond acceptor derivative N,N-dimethylethanolamine is utilized to generate the hydrogen bond acceptor structure in situ on the surface of the carrier, and then the hydrogen bond acceptor and the corresponding hydrogen bond donor urea are mixed to make the hydrogen bond acceptor and the hydrogen bond donor fully interact until the hydrogen bond donor is completely combined with the hydrogen bond acceptor supported by the carrier, the molar ratio of the chloromethyl polystyrene resin and N,N-dimethylethanolamine is 1:1-1:10, and the molar ratio of the supported choline chloride and urea is 3:1-1:3, and finally the chloromethyl polystyrene resin supported deep eutectic solvent material is prepared, and the structural formula is:

2. The method for adsorptive separation of indometacin sodium based on immobilized deep eutectic solvent material according to claim 1, characterized in that The specific preparation steps of the solid supported deep eutectic solvent material are: the chloromethyl polystyrene resin is added to the N-methyl pyrrolidone for swelling for 6-20 h, then N,N-dimethylethanolamine is added, and then reaction is carried out at 70-99 DEG C for 4-24 h, the solid product is washed with deionized water after the reaction is completed and the temperature is cooled to room temperature, and the washed solid product is vacuum dried at 40-60 DEG C for 12-24 h to obtain the supported choline chloride, then the supported choline chloride and urea are uniformly mixed, and finally the chloromethyl polystyrene resin supported deep eutectic solvent material is prepared.

3. The method for adsorptive separation of indometacin sodium based on immobilized deep eutectic solvent material according to claim 1, characterized by The reaction equation in the preparation process of the solid supported deep eutectic solvent material is:

4. The method for adsorptive separation of indometacin sodium based on immobilized deep eutectic solvent material according to claim 1, characterized in that The specific process is: 10 mg of the solid supported deep eutectic solvent material is added to 10 mL of a 0.2-200 mg / L pH=6 indometacin sodium solution, and then constant temperature oscillation is carried out at 30-40 DEG C for 30-40 min to reach adsorption equilibrium, and the removal rate of indometacin sodium in the solution after the reaction is completed is more than 99%.

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