Plant biomass cellulose-based boron adsorbent, and preparation method and application thereof

Abstract

The application discloses a plant biomass cellulose-based boron adsorbent, which comprises a substrate and a ligand grafted on the substrate, the substrate is cellulose grafted glycidyl methacrylate synthesized based on plant biomass cellulose, and the ligand is selected from any one of N-methyl-D-glucose, tris(hydroxymethyl) aminomethane, glycidyl-functionalized ethylenediamine and aldehyde glucose. A preparation method comprises the following steps: obtaining plant biomass cellulose based on plant biomass material; using plant biomass cellulose and glycidyl methacrylate monomers as raw materials, synthesizing cellulose grafted glycidyl methacrylate by adopting an ATRP method; and grafting polyol ligands onto the cellulose grafted glycidyl methacrylate by a hydrothermal reaction, to obtain the plant biomass cellulose-based boron adsorbent. The synthesis method of the boron adsorbent is green and simple, the cost is low, the adsorption capacity is large, and the method is favorable for large-scale application.

Description

Technical Field

[0001] This invention belongs to the field of adsorption materials technology, and particularly relates to a plant biomass cellulose-based boron adsorbent, its preparation method, and its application. Background Technology

[0002] Boron is an important trace element for plants and animals, and also a crucial chemical raw material. Its compounds are widely used in food science, biological science, aerospace, nuclear industry, agricultural science, medicine, materials science, and other industrial production fields. Boron is widely distributed in the ocean, sedimentary rocks, coal, shale, oilfield brine, and soil. High concentrations of boron are beneficial for industrial separation, but excessively high concentrations in aqueous solutions can pose environmental risks. When present in drinking water, it can be harmful to health. The World Health Organization recommends a maximum permissible boron concentration of 2.4 mg / L. Therefore, it is necessary to control the boron content in drinking water and irrigation water.

[0003] The development of boron resources mainly focuses on sedimentary metamorphic solid deposits. However, years of development in solid boron ore mining, characterized by the extraction of high-grade deposits and the abandonment of low-grade deposits, have resulted in boron grades approaching the economic minimum. Developing and utilizing boron resources in salt lake brines is therefore essential. Extracting boron from salt lake brines has become an effective method for addressing boron resource shortages. Currently, methods for separating boron from salt lakes include chemical precipitation, extraction, crystallization, flotation, and adsorption. Each method has its advantages and disadvantages. Adsorption is particularly suitable for areas with fragile ecosystems, poor transportation, and underdeveloped industrial bases, as it is green, environmentally friendly, and highly efficient. Since most salt lakes are located in plateau regions, adsorption has a significant advantage in separating and extracting boron.

[0004] Currently, boron adsorbents used in adsorption methods are mainly inorganic and organic materials. Many boron adsorbents have been developed, including inorganic-organic hybrid adsorbents, biomass adsorbents, polymer adsorbents, and adsorbents bonded to material surfaces through electrostatic interactions, π-π stacking interactions, and coordination bonding. Some boron adsorbents with large adsorption capacities include molecular sieves (MCM-41, SBA-15, SBA-16), layered double hydroxides (Li / Al-LDHs, MgAl-LDHs), and metal-organic frameworks (ZIF-8, ZIF-67, UIO-66). While these adsorbents have large adsorption capacities, they suffer from drawbacks such as high consumption of organic solvents during synthesis, environmental unfriendliness, high cost, and difficulty in degradation, hindering large-scale applications. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a plant biomass cellulose-based boron adsorbent, its preparation method and application. The synthesis method of this boron adsorbent is green and simple, low in cost and has a large adsorption capacity, which is conducive to large-scale application.

[0006] To address the above problems, this invention provides a plant biomass cellulose-based boron adsorbent, comprising a matrix and a ligand grafted onto the matrix. The matrix is ​​cellulose-grafted polyglycidyl methacrylate synthesized from plant biomass cellulose, and the ligand is a polyol ligand selected from any one of N-methyl-D-glucose, tris(hydroxymethyl)methylaminomethane, glycidyl-functionalized ethylenediamine, and aldehyde glucose.

[0007] Preferably, the plant biomass cellulose is cotton linter cellulose.

[0008] This invention also provides a method for preparing the plant biomass cellulose-based boron adsorbent as described above, comprising the following steps:

[0009] S10. Obtaining plant biomass cellulose based on plant biomass materials;

[0010] S20. Using the plant biomass cellulose and glycidyl methacrylate monomer as raw materials, cellulose-grafted polyglycidyl methacrylate is synthesized by ATRP method.

[0011] S30. The polyol ligand is grafted onto the cellulose-grafted polymethyl methacrylate via a hydrothermal reaction to prepare the plant biomass cellulose-based boron adsorbent.

[0012] Preferably, step S10 includes:

[0013] After crushing 1 to 10 parts by weight of plant biomass material, add it to an HCl solution with a concentration of 1 wt% to 8 wt%, stir and seal. Then heat at a temperature of 60℃ to 95℃ for 30 min to 360 min, filter and wash the filter cake until neutral.

[0014] The filter cake, 1-49.5 parts by weight of NaOH, and 1-20 parts by weight of urea are added to 30-100 parts by weight of water and stirred to form a mixed solution. The mixed solution is frozen at -5℃ to -30℃ for 5-36 hours. After freezing, it is taken out and stirred into a viscous paste. After filtration, distilled water is added until neutral to prepare the plant biomass cellulose.

[0015] Preferably, step S20 includes:

[0016] A suspension is formed by mixing and stirring 1-5 parts by weight of the plant biomass cellulose, 50-120 parts by weight of water, 0.05-1 parts by weight of K2S2O8, 0.1-2 parts by weight of Tween-80 and 1-5 parts by weight of glycidyl methacrylate monomer.

[0017] The suspension was transferred to a heating container and heated to 60°C–90°C under a N2 atmosphere with stirring for 2–12 hours. Then, 0.05–0.5 parts by weight of N,N′-methylenebisacrylamide were added, and the reaction was continued with stirring for 1–8 hours. After the reaction was completed, the mixture was filtered and washed to obtain the cellulose-grafted polymethacrylate.

[0018] Wherein, the polyol ligand is N-methyl-D-glucose or tris(hydroxymethyl)methylaminomethane, and step S30 includes:

[0019] 1-5 parts by weight of the cellulose-grafted polyglycidyl methacrylate are stirred and dispersed in 30-100 parts by weight of water, and then 1-8.5 parts by weight of N-methyl-D-glucose or tris(hydroxymethyl)methylaminomethane are added. The mixture is heated to 20°C-85°C and stirred for 2-6 hours to obtain a mixed reaction solution.

[0020] The mixed reaction solution was transferred to a hydrothermal reactor and the hydrothermal reaction was continued at a temperature of 100℃~160℃ for 2h~12h. After the reaction was completed, the solid product was filtered, washed, and freeze-dried to obtain the plant biomass cellulose-based boron adsorbent.

[0021] Wherein, the polyol ligand is glycidyl-functionalized ethylenediamine or aldehyde glucose, and step S30 includes:

[0022] The cellulose-grafted polyglycidyl methacrylate was modified by amylating with an amination agent to obtain amino-modified cellulose-grafted polyglycidyl methacrylate.

[0023] The plant biomass cellulose-based boron adsorbent was prepared by grafting the polyol ligand onto the amino-modified cellulose-grafted polymethacrylate via a hydrothermal reaction.

[0024] Preferably, the step of modifying the cellulose-grafted polyglycidyl methacrylate with an amination agent includes:

[0025] At room temperature, 1-5 parts by weight of the cellulose-grafted polyglycidyl methacrylate and 1-10 parts by weight of the amination reagent are added to 20-100 parts by weight of water, and stirred for 1-5 hours to form a mixed solution; the amination reagent is selected from one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and polyethyleneimine.

[0026] The mixed solution was transferred to a hydrothermal reactor and hydrothermally reacted at 100℃~180℃ for 2h~10h. After the reaction was completed, the solid product was filtered, washed, and freeze-dried to obtain the amino-modified cellulose-grafted polymethacrylate.

[0027] Preferably, the step of grafting the polyol ligand onto the amino-modified cellulose-grafted glycidyl methacrylate via a hydrothermal reaction includes:

[0028] 1-5 parts by weight of the amino-modified cellulose-grafted glycidyl methacrylate are stirred and dispersed in 15-100 parts by weight of water, and then 1-6 parts by weight of glycidyl-functionalized ethylenediamine or aldehyde glucose are added and stirred to obtain a mixed reaction solution.

[0029] The mixed reaction solution was transferred to a hydrothermal reactor and stirred at room temperature for 1 to 6 hours. Then, it was hydrothermally reacted at 100°C to 180°C for 2 to 12 hours. After the reaction was completed, the solid product was filtered, washed, and freeze-dried to obtain the plant biomass cellulose-based boron adsorbent.

[0030] Another aspect of the present invention is to provide an application of the plant biomass cellulose-based boron adsorbent as described above in the adsorption and extraction of boron ions from a boron-containing solution.

[0031] The plant biomass cellulose-based boron adsorbent and its preparation method provided in this invention have a stable structure, high cycle stability, low solubility, large adsorption capacity and are degradable. In the entire synthesis process, water is used as a solvent, eliminating the need for a large amount of organic solvent. The synthesis method is green, simple and low in cost, which is conducive to large-scale industrial application. Attached Figure Description

[0032] Figure 1 These are the infrared spectra of the samples prepared in Examples 1 and 2 of this invention;

[0033] Figure 2 These are infrared spectra of the boron adsorbents prepared in some specific embodiments of the present invention;

[0034] Figure 3 It corresponds to Figure 2 The infrared spectrum of the boron adsorbent after adsorbing boron ions is shown below;

[0035] Figure 4 This is a SEM image of the boron adsorbent prepared in Example 3 of this invention;

[0036] Figure 5 This is a SEM image of the boron adsorbent prepared in Example 4 of this invention;

[0037] Figure 6 This is a SEM image of the boron adsorbent prepared in Example 6 of the present invention;

[0038] Figure 7 This is a SEM image of the boron adsorbent prepared in Example 9 of this invention;

[0039] Figure 8 These are adsorption performance curves of the boron adsorbents prepared in some specific embodiments of the present invention at different pH values.

[0040] Figure 9 These are illustrations of the solubility loss rate test results of the boron adsorbent prepared in some specific embodiments of the present invention after 20 adsorption-desorption cycles;

[0041] Figure 10 These are illustrations of the cycle stability test results of the boron adsorbents prepared in some specific embodiments of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the drawings. The embodiments of the present invention shown in and described with reference to the drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0043] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0044] The present invention provides a plant biomass cellulose-based boron adsorbent and its preparation method.

[0045] The plant biomass cellulose-based boron adsorbent comprises a matrix and ligands grafted onto the matrix. The matrix is ​​cellulose-grafted polyglycidyl methacrylate (Cell-g-PGMA) synthesized from plant biomass cellulose. The ligands are polyol ligands selected from any one of N-methyl-D-glucose (MG), tris(hydroxymethyl)methylaminomethane (Tris), glycidyl-functionalized ethylenediamine (PG), and aldehyde glucose (GLC).

[0046] Preferably, the plant biomass cellulose is cotton linter cellulose. In other embodiments, cellulose can also be prepared from plants containing cellulose, such as cotton, tree bark, or watermelon rind.

[0047] The preparation method of the plant biomass cellulose-based boron adsorbent as described above mainly includes the following steps:

[0048] Step S10: Prepare plant biomass cellulose based on plant biomass materials.

[0049] In the specific solution, step S10 includes the following sub-steps:

[0050] S11. After crushing 1 to 10 parts by weight of plant biomass material, add it to an HCl solution with a concentration of 1 wt% to 8 wt%, stir and seal. Then heat at a temperature of 60℃ to 95℃ for 30 min to 360 min, filter and wash the filter cake until neutral.

[0051] S12. The filter cake, 1-49.5 parts by weight of NaOH, and 1-20 parts by weight of urea are added to 30-100 parts by weight of water and stirred to form a mixed solution. The mixed solution is frozen at -5℃ to -30℃ for 5-36 hours. After freezing, it is taken out and stirred into a viscous paste. After filtration, distilled water is added until neutral to prepare the plant biomass cellulose.

[0052] Step S20: Using the plant biomass cellulose and glycidyl methacrylate monomer as raw materials, cellulose-grafted polyglycidyl methacrylate (Cell-g-PGMA) is synthesized by ATRP method.

[0053] In the specific solution, step S20 includes the following sub-steps:

[0054] S21. Mix and stir 1-5 parts by weight of the plant biomass cellulose, 50-120 parts by weight of water, 0.05-1 parts by weight of K2S2O8, 0.1-2 parts by weight of Tween-80 and 1-5 parts by weight of glycidyl methacrylate (GMA) monomer to form a suspension.

[0055] S22. The suspension is transferred to a heating container and heated to 60°C–90°C under a N2 atmosphere with stirring for 2–12 hours. Then, 0.05–0.5 parts by weight of N,N′-methylenebisacrylamide are added, and the mixture is stirred for another 1–8 hours. After the reaction is complete, the mixture is filtered and washed to obtain the cellulose-grafted poly(glycidyl methacrylate) (Cell-g-PGMA).

[0056] Step S30: The polyol ligand is grafted onto the cellulose-grafted polymethyl methacrylate via a hydrothermal reaction to prepare the plant biomass cellulose-based boron adsorbent.

[0057] Wherein, when the polyol ligand is selected as N-methyl-D-glucose (MG) or tris(hydroxymethyl)methylaminomethane (Tris), step S30 includes the following sub-steps:

[0058] S301. Disperse 1-5 parts by weight of the cellulose-grafted polyglycidyl methacrylate in 30-100 parts by weight of water, then add 1-8.5 parts by weight of N-methyl-D-glucose or tris(hydroxymethyl)methylaminomethane, heat to 20°C-85°C and stir for 2-6 hours to obtain a mixed reaction solution.

[0059] S302. The mixed reaction solution is transferred to a hydrothermal reactor and the hydrothermal reaction is continued at a temperature of 100℃~160℃ for 2h~12h. After the reaction is completed, the solid product is filtered, washed, and freeze-dried to obtain the plant biomass cellulose-based boron adsorbent (Cell-g-PGMA-MG or Cell-g-PGMA-MG-Tris).

[0060] Wherein, when the polyol ligand is glycidyl-functionalized ethylenediamine (PG) or aldehyde glucose (GLC), in step S30, firstly, the cellulose-grafted glycidyl methacrylate is aminated using an amination reagent to obtain aminated cellulose-grafted glycidyl methacrylate; then, the polyol ligand is grafted onto the aminated cellulose-grafted glycidyl methacrylate via a hydrothermal reaction to prepare the plant biomass cellulose-based boron adsorbent. Specifically, the following sub-steps are included:

[0061] S311. At room temperature, 1-5 parts by weight of the cellulose-grafted polyglycidyl methacrylate and 1-10 parts by weight of the amination reagent are added to 20-100 parts by weight of water, and stirred for 1-5 hours to form a mixed solution; the amination reagent is selected from one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and polyethyleneimine.

[0062] S312. The mixed solution is transferred to a hydrothermal reactor and hydrothermally reacted at 100℃~180℃ for 2h~10h. After the reaction is completed, the solid product is filtered, washed, and freeze-dried to obtain the amino-modified cellulose-grafted poly(glycidyl methacrylate) (Cell-g-PGMA-xNH2, where x is an integer greater than or equal to 2, and x represents the number of amino groups).

[0063] S313. Disperse 1-5 parts by weight of the amino-modified cellulose-grafted polyglycidyl methacrylate in 15-100 parts by weight of water, then add 1-6 parts by weight of glycidyl-functionalized ethylenediamine or aldehyde glucose, and stir to obtain a mixed reaction solution.

[0064] S314. The mixed reaction solution is transferred to a hydrothermal reactor, and the mixture is stirred at room temperature for 1 to 6 hours. Then, it is hydrothermally reacted at 100°C to 180°C for 2 to 12 hours. After the reaction is completed, the solid product is filtered, washed, and freeze-dried to obtain the plant biomass cellulose-based boron adsorbent.

[0065] Based on the plant biomass cellulose-based boron adsorbent and its preparation method as described above, the boron adsorbent is mainly used for adsorbing and extracting boron ions from boron-containing solutions.

[0066] Example 1: Preparation of cotton linter cellulose

[0067] Cotton linters (3g) were pulverized and dissolved in 3wt% HCl (36g), stirred and sealed, heated at 95℃ for 120 min, filtered, and the filter cake was washed until neutral. Then, NaOH (4.5g), urea (3g), and H2O (42g) were added and stirred, and the mixture was frozen at -20℃ for 24 h. After removal, it was quickly stirred into a viscous paste, filtered, and distilled water was added until neutral to obtain cotton linter cellulose (Cell). It should be noted that the product obtained in this step does not need to be dried in order to improve the grafting rate of subsequent intermediates.

[0068] The infrared spectrum of the cotton linter cellulose (Cell) prepared in this embodiment is shown in the figure below. Figure 1 .

[0069] Example 2: Preparation of cotton linter cellulose copolymer Cell-g-PGMA

[0070] Using the ATRP method, Cell (2g), H2O (100g), K2S2O8 (0.1g), Tween-80 (0.12g), and GMA (2g) obtained in Example 1 were mixed and stirred until homogeneous. The suspension was then transferred to a 250mL flask, heated to 90℃, and stirred for 12h under a N2 atmosphere. Then, N,N′-methylenebisacrylamide (0.1g) was added, and the reaction was stirred for another 3h. The product was filtered and washed three times (3×30mL) with ethanol / water (1:1) to obtain the cotton linter cellulose copolymer Cell-g-PGMA.

[0071] The infrared spectrum of the copolymer Cell-g-PGMA prepared in this embodiment is shown in the figure. Figure 1 .

[0072] Example 3: Preparation of boron adsorbent Cell-g-PGMA-MG

[0073] Cell-g-PGMA (2g) obtained in Example 2 was dispersed in 30g of H2O, and the mixture was mechanically stirred. Then, ligand MG (3.5g) was added to the mixture, and stirring continued. The mixture was heated to 35°C and stirred for 2 hours, then transferred to a hydrothermal reactor, and the reaction was continued at 110°C for 8 hours. After the reaction was completed, the product was filtered and washed three times with deionized water (100mL). The product was freeze-dried for 24 hours to obtain the boron adsorbent Cell-g-PGMA-MG.

[0074] The infrared spectrum of the boron adsorbent Cell-g-PGMA-MG prepared in this embodiment is shown in the figure below. Figure 2 The infrared spectrum of the adsorbent after boron adsorption (Cell-g-PGMA-MG-B) is shown below. Figure 3 . Figure 4 This is a SEM image of the boron adsorbent Cell-g-PGMA-MG prepared in this embodiment.

[0075] The adsorption performance of the boron adsorbent Cell-g-PGMA-MG prepared in this embodiment was tested. The test steps included: accurately weighing 3g of the adsorbent into seven 50mL portions of boron solution with a concentration of 500mg / L, wherein the pH values ​​of the seven boron solutions were adjusted to 4, 5, 6, 7, 8, 9, and 10 respectively. After sealing, the solutions were placed in a constant temperature water bath shaker (25℃, 200rpm / min) and shaken for 24h. The supernatant was then diluted and brought to a final volume. The boron content was determined by ICP, and the equilibrium adsorption capacity was calculated. A curve showing the change in adsorption capacity as a function of pH was obtained by plotting the adsorption capacity against pH. Figure 8 As shown. In this embodiment, the boron adsorbent Cell-g-PGMA-MG exhibits the highest adsorption capacity (25.89 mg / g) at a boron solution pH of 9. After 20 adsorption-desorption cycles, the dissolution rate of the boron adsorbent Cell-g-PGMA-MG in this embodiment is only 0.86%. (See [reference needed]). Figure 9 The test results are illustrated in the figure. The boron adsorbent Cell-g-PGMA-MG in this embodiment exhibits high cycle stability; see [link to relevant documentation]. Figure 10 The test results are illustrated.

[0076] Example 4: Preparation of boron adsorbent Cell-g-PGMA-Tris

[0077] Cell-g-PGMA (2g) obtained in Example 2 was dispersed in 30g of H2O and the mixture was mechanically stirred. Then, ligand Tris (3g) was added to the mixture and stirring continued. The mixture was heated to 35°C and stirred for 2 hours, then transferred to a hydrothermal reactor and the reaction was continued at 120°C for 8 hours. After the reaction was completed, the product was filtered and washed three times with deionized water (100mL). The product was freeze-dried for 24 hours to obtain the boron adsorbent Cell-g-PGMA-Tris.

[0078] The infrared spectrum of the boron adsorbent Cell-g-PGMA-Tris prepared in this embodiment is shown in the figure. Figure 2 The infrared spectrum of the adsorbent after boron adsorption (Cell-g-PGMA-Tris-B) is shown below. Figure 3 . Figure 5 This is a SEM image of the boron adsorbent Cell-g-PGMA-Tris prepared in this embodiment.

[0079] The adsorption performance of the boron adsorbent Cell-g-PGMA-Tris prepared in this embodiment was tested, and the testing procedure was the same as in Example 3. Figure 8 As shown, the boron adsorbent Cell-g-PGMA-Tris in this embodiment exhibits the highest adsorption capacity (15.89 mg / g) at a boron solution pH of 8. After 20 adsorption-desorption cycles, the solubility loss rate of the boron adsorbent Cell-g-PGMA-Tris in this embodiment is only 0.83%. (See [link to relevant documentation]). Figure 9 The test results are illustrated in the figure. The boron adsorbent Cell-g-PGMA-Tris in this embodiment exhibits high cycle stability; see [link to relevant documentation]. Figure 10 The test results are illustrated.

[0080] Example 5: Preparation of amino-modified cellulose copolymer Cell-g-PGMA-2NH2

[0081] At room temperature, 2 g of Cell-g-PGMA obtained in Example 2 and 5 g of ethylenediamine (EN) were added to 20 g of H2O and stirred continuously. The mixture was stirred at room temperature for 3 h, and then transferred to a hydrothermal reactor, where the reaction was continued at 110 °C for 10 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and washed three times with deionized water (100 mL).

[0082] The product was freeze-dried for 24 hours to obtain an amino-modified cellulose copolymer, Cell-g-PGMA-2NH2.

[0083] Example 6: Preparation of boron adsorbent Cell-g-PGMA-2PG

[0084] Cell-g-PGMA-2NH2 (2g) obtained in Example 5 was dispersed in 15g of H2O. The mixture was mechanically stirred until homogeneous, and then 3g of glycidyl (PG) was added dropwise to the mixture. The mixture was stirred in a hydrothermal reactor at room temperature for 3 hours, and then at 105°C for 8 hours. The product was filtered, washed with deionized water (3 × 100 mL), and freeze-dried to obtain the boron adsorbent Cell-g-PGMA-2PG.

[0085] The infrared spectrum of the boron adsorbent Cell-g-PGMA-2PG prepared in this embodiment is shown in the figure. Figure 2 The infrared spectrum of the adsorbent after boron adsorption (Cell-g-PGMA-2PG-B) is shown below. Figure 3 . Figure 6 This is a SEM image of the boron adsorbent Cell-g-PGMA-2PG prepared in this embodiment.

[0086] The adsorption performance of the boron adsorbent Cell-g-PGMA-2PG prepared in this embodiment was tested, and the testing procedure was the same as in Example 3. Figure 8 As shown, the boron adsorbent Cell-g-PGMA-2PG in this embodiment exhibits the highest adsorption capacity (27.93 mg / g) at a boron solution pH of 9. After 20 adsorption-desorption cycles, the solubility loss rate of the boron adsorbent Cell-g-PGMA-2PG in this embodiment is only 0.87%. (See [link to relevant documentation]). Figure 9 The test results are illustrated in the figure. The boron adsorbent Cell-g-PGMA-2PG in this embodiment exhibits high cycle stability; see [link to relevant documentation]. Figure 10 The test results are illustrated.

[0087] Example 7: Preparation of amino-modified cellulose copolymer Cell-g-PGMA-3NH2

[0088] At room temperature, 2 g of Cell-g-PGMA obtained in Example 2 and 5 g of triethylenetetramine (EN3) were added to 30 g of H2O and stirred continuously. The mixture was stirred at room temperature for 2 h, and then transferred to a hydrothermal reactor, where the reaction was continued at 120 °C for 8 h. After the reaction was completed, the mixture was cooled to room temperature, the product was filtered, and washed three times with deionized water (100 mL).

[0089] The product was freeze-dried for 24 hours to obtain an amino-modified cellulose copolymer, Cell-g-PGMA-3NH2.

[0090] Example 8: Preparation of boron adsorbent Cell-g-PGMA-3PG

[0091] The Cell-g-PGMA-3NH2 (3g) obtained in Example 7 was dispersed in 50g of H2O. The mixture was mechanically stirred until homogeneous, and then 3g of glycidyl (PG) was added dropwise to the mixture. The mixture was stirred in a hydrothermal reactor at room temperature for 3 hours, and then at 110°C for 8 hours. The product was filtered, washed with deionized water (3 × 100 mL), and freeze-dried to obtain the boron adsorbent Cell-g-PGMA-3PG.

[0092] The adsorption performance of the boron adsorbent Cell-g-PGMA-3PG prepared in this embodiment was tested, and the testing procedure was the same as in Example 3. The boron adsorbent Cell-g-PGMA-3PG in this embodiment exhibited the highest adsorption capacity (30 mg / g) at a boron solution pH of 9.

[0093] Example 9: Preparation of boron adsorbent Cell-g-PGMA-GLC

[0094] The Cell-g-PGMA-NH2 (2g) obtained in Example 5 was dispersed in 50g of H2O. The mixture was mechanically stirred until homogeneous, and then 3g of aldehyde glucose (GLC) was added dropwise to the mixture. The mixture was stirred continuously at room temperature for 3h in a hydrothermal reactor, followed by stirring at 120°C for 6h. The product was filtered, washed with deionized water (3 × 100mL), and freeze-dried to obtain the boron adsorbent Cell-g-PGMA-GLC.

[0095] Figure 7 This is a SEM image of the boron adsorbent Cell-g-PGMA-GLC prepared in this embodiment.

[0096] The adsorption performance of the boron adsorbent Cell-g-PGMA-GLC prepared in this embodiment was tested, and the testing procedure was the same as in Example 3. Figure 8 As shown, the boron adsorbent Cell-g-PGMA-GLC in this embodiment exhibits the highest adsorption capacity (26 mg / g) at a boron solution pH of 9. After 20 adsorption-desorption cycles, the solubility loss rate of the boron adsorbent Cell-g-PGMA-GLC in this embodiment is only 0.86%. (See [link to relevant documentation]). Figure 9 The test results are illustrated.

[0097] In summary, the plant biomass cellulose-based boron adsorbent and its preparation method provided in this embodiment of the invention result in a boron adsorbent with stable structure, high cycle stability, low solubility, large adsorption capacity, and biodegradability. The entire synthesis process uses water as a solvent, eliminating the need for large amounts of organic solvents. The synthesis method is green, simple, and low-cost, which is conducive to large-scale industrial applications.

[0098] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An application of a plant biomass cellulose-based boron adsorbent in the adsorption and extraction of boron ions from a boron-containing solution, characterized in that, It includes a matrix and a polyol ligand grafted onto the matrix, wherein the matrix is ​​cellulose-grafted polyglycidyl methacrylate synthesized based on plant biomass cellulose, the polyol ligand is glycidyl methacrylate, and the plant biomass cellulose is cotton linter cellulose; The preparation method of the plant biomass cellulose-based boron adsorbent includes the following steps: S10. Obtaining plant biomass cellulose based on plant biomass materials; S20. Using the plant biomass cellulose and glycidyl methacrylate monomer as raw materials, cellulose-grafted polyglycidyl methacrylate is synthesized by ATRP method. S30. The polyol ligand is grafted onto the cellulose-grafted polymethyl methacrylate via a hydrothermal reaction to prepare the plant biomass cellulose-based boron adsorbent. Step S30 includes: modifying the cellulose-grafted poly(glycidyl methacrylate) with an amination reagent to obtain an amino-modified cellulose-grafted poly(glycidyl methacrylate); and preparing the plant biomass cellulose-based boron adsorbent by grafting the polyol ligand onto the amino-modified cellulose-grafted poly(glycidyl methacrylate) via a hydrothermal reaction. The step of modifying the cellulose-grafted polyglycidyl methacrylate with an amination reagent includes: adding 1-5 parts by weight of the cellulose-grafted polyglycidyl methacrylate and 1-10 parts by weight of the amination reagent to 20-100 parts by weight of water at room temperature, and stirring for 1-5 hours to form a mixed solution; the amination reagent is selected from one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and polyethyleneimine; transferring the mixed solution to a hydrothermal reactor, and hydrothermally reacting at 100-180°C for 2-10 hours; after the reaction, filtering and washing the solid product, and freeze-drying to obtain the amination-modified cellulose-grafted polyglycidyl methacrylate; The step of grafting the polyol ligand onto the amino-modified cellulose-grafted glycidyl methacrylate via hydrothermal reaction includes: dispersing 1-5 parts by weight of the amino-modified cellulose-grafted glycidyl methacrylate in 15-100 parts by weight of water, adding 1-6 parts by weight of glycidyl methacrylate, and stirring to obtain a mixed reaction solution; transferring the mixed reaction solution to a hydrothermal reactor, stirring and reacting at room temperature for 1-6 hours, and then hydrothermally reacting at 100-180°C for 2-12 hours; after the reaction, filtering and washing the solid product, and freeze-drying to obtain the plant biomass cellulose-based boron adsorbent.

2. The application according to claim 1, characterized in that, Step S10 includes: After crushing 1 to 10 parts by weight of plant biomass material, add it to an HCl solution with a concentration of 1 wt% to 8 wt%, stir and seal. Then heat at a temperature of 60°C to 95°C for 30 min to 360 min, filter and wash the filter cake until neutral. The filter cake, 1-49.5 parts by weight of NaOH, and 1-20 parts by weight of urea are added to 30-100 parts by weight of water and stirred to form a mixed solution. The mixed solution is frozen at -5°C to -30°C for 5-36 hours. After freezing, it is taken out and stirred into a viscous paste. After filtration, distilled water is added until neutral to prepare the plant biomass cellulose.

3. The application according to claim 1, characterized in that, Step S20 includes: A suspension is formed by mixing and stirring 1-5 parts by weight of the plant biomass cellulose, 50-120 parts by weight of water, 0.05-1 parts by weight of K2S2O8, 0.1-2 parts by weight of Tween-80 and 1-5 parts by weight of glycidyl methacrylate monomer. The suspension was transferred to a heating container and heated to 60°C~90°C under a N2 atmosphere with stirring for 2h~12h. Then, 0.05~0.5 parts by mass of N,N′-methylenebisacrylamide were added, and the reaction was continued with stirring for 1h~8h. After the reaction was completed, the mixture was filtered and washed to obtain the cellulose-grafted polymethacrylate.

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