An intercalated coal gangue-based surface molecular imprinting adsorption material and a preparation method thereof

Abstract

The application discloses an intercalation coal gangue-based surface molecular imprinting adsorption material and a preparation method. First, intercalation coal gangue is used as a carrier, phenol is used as a template molecule, methacrylic acid is used as a functional monomer, ethylene glycol dimethacrylate is used as a crosslinking agent, azobisisobutyronitrile is used as an initiator, a surface molecular imprinting reaction is carried out on the surface of the intercalation coal gangue, and a polymer layer is formed. The layer fixes the template molecule and the functional monomer assembly together. The phenol template molecule is removed by elution, and finally, the intercalation coal gangue-based surface molecular imprinting adsorption material with a structure having a specific adsorption pore size is obtained. The intercalation coal gangue-based surface molecular imprinting adsorption material is prepared by mixing coal gangue as raw material after treatment with a solution of an intercalation agent with a certain concentration. The intercalation process includes direct intercalation of dimethyl sulfoxide, two intercalations of methanol, and macromolecular intercalation of cetyltrimethylammonium bromide, the intercalation process and imprinting effect are optimized, and the specific adsorption of phenol on the phenol adsorption performance is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment adsorption materials and relates to an intercalated gangue-based surface molecular imprinting adsorption material and a preparation method thereof. Background Art

[0002] Coal chemical wastewater is characterized by large volumes of water, complex composition, and a high concentration of organic matter. Phenol, a common organic substance, is highly toxic and irritating. Long-term exposure to phenol-containing wastewater can cause damage to the nervous, liver, and respiratory systems of organisms. China has designated phenol as a priority pollutant, requiring phenol concentrations in treated water to be below 1 mg / L. Therefore, the selective treatment and recovery of phenol in coal chemical wastewater is particularly important.

[0003] In the precise recovery of phenol-containing wastewater, molecular imprinting technology is widely used due to its highly selective adsorption capacity and good stability. Juncheng Zhang et al. used porous carbon gel as a carrier to prepare a three-dimensional monolithic surface molecularly imprinted polymer adsorbent, which was successfully applied to alkaline wastewater with complex components, showing an adsorption capacity of 58.4 mg / g for phenol. On the other hand, Feifei Duan et al. used porous graphene oxide as a carrier to prepare a surface molecularly imprinted polymer adsorbent and successfully applied it to real river water, with an adsorption capacity of up to 60.6 mg / g for bisphenol A. In addition, patent CN 117599759 A describes a three-dimensional macroscopic block-shaped high adsorption activity imprinted adsorbent material formed by hydrothermal imprinting reaction using chitosan carbon aerogel as a matrix. The material can adsorb up to 42.5 mg / g of phenol. These studies fully demonstrate the potential and application prospects of molecularly imprinted materials in the treatment of phenol pollutants. Coal gangue, the primary solid waste generated during coal mineralization, accounts for approximately 15% to 25% of total coal mining emissions annually, making it one of the largest solid waste streams globally. However, gangue's rich porosity and high surface area favor the formation of more imprinted pores, thereby enhancing selectivity for target molecules. Therefore, the effective utilization of gangue, particularly its use as a carrier for the preparation of selective adsorption materials, holds great research and development value and potential. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems in the prior art and provide an intercalated gangue-based surface molecularly imprinted adsorption material and a preparation method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing an intercalated gangue-based surface molecularly imprinted adsorption material, comprising:

[0007] Using coal gangue as raw material, an intercalation reaction occurs in a solution containing an intercalation agent, and intercalated coal gangue is formed through centrifugal separation and drying;

[0008] Using intercalated coal gangue as a carrier, phenol and methacrylic acid were added to acetonitrile solvent under an inert atmosphere for a preliminary reaction, and then a cross-linking agent and an initiator were added to carry out a surface imprinting reaction to obtain an imprinting reaction product.

[0009] The imprinting reaction product is treated to obtain intercalated coal gangue-based surface molecular imprinting adsorption material.

[0010] Preferably, the intercalation reaction includes a direct intercalation reaction of dimethyl sulfoxide, a double intercalation reaction of methanol, and a macromolecular intercalation reaction of hexadecyltrimethylammonium bromide.

[0011] Preferably, the intercalated gangue is mixed with a dimethyl sulfoxide intercalation agent solution, magnetically stirred under heating conditions, and then centrifuged and dried to obtain the directly intercalated gangue;

[0012] Direct intercalation of coal gangue and methanol solution, magnetic stirring under heating conditions, centrifugal separation, pouring the upper solution, to obtain methanol twice intercalated coal gangue;

[0013] The methanol twice intercalated coal gangue is mixed with a methanol solution of hexadecyltrimethylammonium bromide, the two are stirred evenly, and the product is repeatedly washed with an ethanol solution, and the hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue is obtained after filtration.

[0014] Preferably, the gangue and the dimethyl sulfoxide solution are stirred at 60°C to 70°C for 20h to 24h at a stirring speed of 300 r / min to 500r / min; the centrifugal speed is 4000 r / min to 5000r / min, the centrifugal time is 3min to 5min, and finally dried at 60°C to 70°C for 20h to 24h to obtain directly intercalated gangue; wherein the addition ratio of gangue to dimethyl sulfoxide solution is 8g to 10g: 100ml to 200ml;

[0015] Direct intercalation gangue and methanol are magnetically stirred at 50°C to 60°C for 20h to 24h, then centrifuged at a speed of 4000 r / min to 5000 r / min for 3min to 5min, and finally dried at 60°C to 70°C for 20h to 24h to obtain methanol twice intercalated gangue; wherein the dosage ratio of direct intercalation gangue to methanol is 3g to 5g:80ml to 100ml;

[0016] The methanol-intercalated coal gangue was mixed with a methanol solution of hexadecyltrimethylammonium bromide, magnetically stirred at 50°C to 60°C for 20h to 24h, then centrifuged at a speed of 4000 r / min to 5000 r / min for 3min to 5min, and finally dried at 60°C to 70°C for 20h to 24h to obtain hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue;

[0017] The ratio of methanol twice intercalated coal gangue to methanol solution of hexadecyltrimethylammonium bromide is 3g~5g:80~100ml.

[0018] Preferably, the gangue needs to be ground to 200-350 mesh and calcined at 700-800° C.; the mass ratio of the dimethyl sulfoxide solution to water is 9:1-9:2; and the concentration of the methanol solution of hexadecyltrimethylammonium bromide is 20 mg / L-30 mg / L.

[0019] Preferably, during the preliminary reaction, the mass ratio of intercalated coal gangue, phenol, and methacrylic acid is (1-3): (0.5-1): (2-9); the reaction temperature is controlled at 20° C. to 30° C., and the reaction time is 1 h to 2 h.

[0020] Preferably, during the surface imprinting reaction, the crosslinking agent is ethylene glycol dimethacrylate, the initiator is azobisisobutyronitrile, the mass ratio of ethylene glycol dimethacrylate to azobisisobutyronitrile is (0.5-1.5): (0.1-0.45), the reaction temperature is controlled at 60°C-70°C, and the reaction time is 22h-24h.

[0021] Preferably, the imprinting reaction product is processed to obtain the intercalated gangue-based surface molecularly imprinted adsorption material, specifically:

[0022] The imprinted reaction product is washed with a mixture of methanol and acetic acid as an eluent to remove the phenol template molecules on the imprinted reaction product; the washed imprinted reaction product is dried to obtain an intercalated coal gangue-based surface molecular imprinted adsorption material.

[0023] Preferably, the volume ratio of methanol to acetic acid is 9:1 to 9:2, and the washed imprinted reaction product is dried for 12 to 14 hours.

[0024] The invention discloses an intercalated coal gangue-based surface molecular imprinted adsorption material, which is prepared by adopting a preparation method of the intercalated coal gangue-based surface molecular imprinted adsorption material.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a method for preparing an intercalated gangue-based surface molecularly imprinted adsorbent material. By utilizing the rich pore structure of the gangue surface and modifying it through a surface modification method, a structure with a specific adsorption pore size is formed. This structure significantly improves the adsorption capacity and specificity of the intercalated gangue material for phenol, enabling efficient and specific adsorption of phenol in complex coal chemical wastewater. The method first uses the intercalated gangue as a carrier, phenol as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and azobisisobutyronitrile as an initiator. A surface molecular imprinting reaction is performed on the intercalated gangue surface to form a polymer layer. This layer secures the template molecule and the functional monomer assembly. Subsequently, the phenol template molecules are removed by elution, ultimately yielding an intercalated gangue-based surface molecularly imprinted adsorbent material with a structure having a specific adsorption pore size. The intercalated gangue is prepared by grinding and calcining the gangue raw material and then mixing it with an intercalating agent solution of a certain concentration. The intercalation process includes direct intercalation of dimethyl sulfoxide using dimethyl sulfoxide, two intercalations of methanol, and macromolecular intercalation of hexadecyltrimethylammonium bromide. The intercalated coal gangue-based surface molecularly imprinted adsorption material of the present invention assembles and fixes phenol template molecules and functional monomers in a cross-linked polymer layer through a surface imprinting reaction. After eluting and removing the phenol template molecules with a mixture of methanol and acetic acid, a large number of pore structures that specifically recognize phenol molecules are formed on the surface of the material. This structure enables the intercalated coal gangue-based surface molecularly imprinted adsorption material to efficiently and selectively adsorb phenol molecules. The present invention utilizes the abundant pore size and active sites of the intercalated coal gangue, and introduces active groups by covalently or physically adsorbing methacrylic acid as a functional monomer to the coal gangue surface. At the same time, ethylene glycol dimethacrylate, as a cross-linking agent, can form a stable network structure, enhancing the mechanical strength and chemical stability of the modified layer. This surface modification process improves the surface properties of the intercalated coal gangue, making it an efficient intercalated coal gangue-based surface molecular imprinting adsorption material, achieving specific recognition and efficient adsorption capacity for phenol. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 These are scanning electron microscopy analysis of the coal gangue of Example 1 (a), scanning electron microscopy analysis of the coal gangue intercalated with hexadecyltrimethylammonium bromide macromolecules (b), and scanning electron microscopy analysis of the molecularly imprinted adsorption material on the intercalated coal gangue-based surface (c).

[0029] Figure 2 These are the Fourier transform infrared diffuse reflectance spectrometer analysis diagram of the intercalated gangue-based surface molecular imprinting adsorption material of Example 1 (a), the specific surface area analysis diagram of the gangue and intercalated gangue-based surface molecular imprinting adsorption material (b), and the pore structure analysis diagram of the gangue and intercalated gangue-based surface molecular imprinting adsorption material (c).

[0030] Figure 3 This is the selective adsorption performance of the intercalated gangue-based surface molecular imprinting adsorption material in Example 1.

[0031] Figure 4 This is a diagram of the adsorption device in Example 1. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0035] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] The present invention is described in further detail below with reference to the accompanying drawings:

[0037] The present invention provides a method for preparing a suitable intercalated gangue-based surface molecularly imprinted adsorption material, comprising the following steps:

[0038] 1) Using coal gangue as raw material, multiple intercalation reactions occur in a solution containing an intercalation agent, and intercalated coal gangue is formed after centrifugal separation and drying.

[0039] 2) This invention uses intercalated coal gangue as a support. Under an inert atmosphere, a phenol template molecule and a methacrylic acid functional monomer are added to an acetonitrile solvent system for a preliminary reaction. Subsequently, ethylene glycol dimethacrylate is added as a crosslinker and azobisisobutyronitrile as an initiator to carry out a surface imprinting reaction. This process effectively fixes the template molecule and functional monomer on the pore structure of the intercalated coal gangue support, ultimately producing the imprinted reaction product.

[0040] 3) The phenol template molecules on the imprinted reaction product are eluted and removed to obtain a three-pore intercalated coal gangue-based surface molecularly imprinted adsorption material with rich specific recognition of phenol molecules.

[0041] The invention adopts multiple intercalation reactions of coal gangue, including direct intercalation of dimethyl sulfoxide, double intercalation of methanol, and macromolecular intercalation of hexadecyltrimethylammonium bromide.

[0042] Specifically, the method comprises the following steps: firstly, mixing the mixture with a dimethyl sulfoxide intercalation agent solution of a certain concentration, magnetically stirring the mixture for several hours under heating conditions, and then centrifuging and drying the mixture to obtain directly intercalated coal gangue; mixing the directly intercalated coal gangue with a certain amount of methanol solution, magnetically stirring the mixture for several hours under heating conditions, centrifuging and separating the mixture, and pouring the upper layer solution to obtain methanol twice intercalated coal gangue; mixing the methanol twice intercalated coal gangue with a methanol solution of hexadecyltrimethylammonium bromide of a certain concentration, placing the two mixtures in a beaker and stirring them evenly, and then repeatedly washing the product with an ethanol solution, and filtering the mixture to obtain hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue.

[0043] More specifically, 8-10 g of coal gangue and 100-200 ml of dimethyl sulfoxide solution were stirred at 60-70 ° C for 20-24 h at a stirring speed of 300-500 r / min; the centrifugal speed was 4000-5000 r / min, the centrifugal time was 3-5 min, and finally the mixture was dried at 60-70 ° C for 20-24 h to obtain directly intercalated coal gangue; 3-5 g of directly intercalated coal gangue and 80-100 ml of methanol were magnetically stirred at 50-60 ° C for 20-24 h at a stirring speed of 400-500 r / min, then centrifugation, the centrifugal speed is 4000~5000r / min, the centrifugal time is 3~5min, and finally drying at 60~70℃ for 20~24h to obtain methanol twice intercalated coal gangue; 3~5g of methanol twice intercalated coal gangue is taken and mixed with 80~100ml of methanol solution of hexadecyltrimethylammonium bromide, magnetically stirred at 50~60℃ for 20~24h, the stirring speed is 400~500r / min, then centrifugation, the centrifugal speed is 4000~5000r / min, the centrifugal time is 3~5min, and finally drying at 60~70℃ for 20~24h to obtain hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue.

[0044] The preferred coal gangue needs to be ground to 200-350 mesh; the mass ratio of dimethyl sulfoxide solution to water is 9:1-9:2; and 20 mg / L-30 mg / L of hexadecyltrimethylammonium bromide methanol solution is added.

[0045] The present invention introduces a methacrylic acid functional monomer and a phenol template to prepare a molecularly imprinted adsorption material for intercalated gangue-based surfaces. The methacrylic acid effectively modifies the rich pore structure of the intercalated gangue and forms a moderate interaction with the phenol template molecules. After the imprinting reaction and elution, the material can more easily form a matching pore structure with phenol.

[0046] Phenol, hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue and methacrylic acid are dissolved in 25~35mL acetonitrile solvent, nitrogen is introduced for 3~7min and then sealed, and magnetic stirring is carried out at 20℃~30℃ for 1h~2h with a stirring speed of 380~420r / min; then ethylene glycol dimethacrylate and azobisisobutyronitrile are added, nitrogen is introduced again for 3~5min and then sealed, and magnetic stirring is carried out at 60℃~70℃ for 22h~24h with a stirring speed of 380~420r / min. Phenol and methacrylic acid are modified near the pores of the intercalated coal gangue to obtain an imprinted product.

[0047] Among them, the mass ratio of intercalated coal gangue, phenol and methacrylic acid is (1~3): (0.5~1): (2~9); the mass ratio of ethylene glycol dimethacrylate and azobisisobutyronitrile is (0.5~1.5): (0.1~0.45).

[0048] Since phenol is readily soluble in a mixture of methanol and acetic acid, the present invention preferably uses a mixture of methanol and acetic acid (in a ratio of 9:1 to 9:2) as the eluent to remove the phenol template molecules from the imprinted reaction product. The washed imprinted reaction product is dried in a vacuum freeze dryer for 12 to 14 hours to obtain an intercalated gangue-based surface molecularly imprinted adsorption material.

[0049] Example 1

[0050] Take 200 mesh coal gangue (the scanning electron microscope analysis is shown in the attached Figure 1 10 g of a) in a beaker is prepared with dimethyl sulfoxide solution and water in a mass ratio of 9:1, and then 100 ml of dimethyl sulfoxide solution is added. The mixture is stirred at 60°C for 24 h at a stirring speed of 300 r / min; the mixture is centrifuged at a speed of 4000 r / min for 3 min; and the precipitate is placed in a drying oven and dried at 60°C for 24 h to obtain directly intercalated coal gangue.

[0051] Take 5 g of directly intercalated coal gangue and 80 ml of methanol, magnetically stir at 60°C for 24 hours with a stirring speed of 400 r / min; centrifuge at a speed of 4000 r / min and a centrifugal time of 3 minutes; pour off the upper solution, and finally dry at 60°C for 20 hours to obtain methanol twice intercalated coal gangue.

[0052] Take 5g of methanol-intercalated coal gangue and 80ml of 20mg / L methanol solution of hexadecyltrimethylammonium bromide, mix them, place them in a beaker, stir them magnetically at 50℃ for 24h, stir at 400r / min, centrifuge at 5000r / min, and centrifuge for 5min; then wash the product repeatedly with ethanol solution, filter and dry at 60℃ for 24h to obtain hexadecyltrimethylammonium bromide macromolecule intercalated coal gangue (the scanning electron microscopy analysis is shown in the attached figure). Figure 1 b) in the above example.

[0053] Take 1g of phenol, 0.5g of hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue and 4mL of methacrylic acid and dissolve them in 25mL of acetonitrile solvent. After nitrogen is introduced for 3 minutes, it is sealed and magnetically stirred for 2h at 20℃ with a stirring speed of 380r / min. Then add 1mL of ethylene glycol dimethacrylate and 0.15g of azobisisobutyronitrile, introduce nitrogen again for 3 minutes and seal, and magnetically stir for 22h at 70℃ with a stirring speed of 380r / min. Phenol and methacrylic acid are modified near the pores of the intercalated coal gangue to obtain an imprinted product.

[0054] A methanol / acetic acid mixture (ratio 9:1) was used as the eluent to remove the phenol template molecules on the imprinted reaction product. The washed imprinted reaction product was dried in a vacuum freeze dryer for 12 hours to obtain the intercalated coal gangue-based surface molecularly imprinted adsorption material (the scanning electron microscopy analysis is shown in the attached figure). Figure 1 c)

[0055] 0.2 g of intercalated gangue-based surface molecularly imprinted adsorption material was adsorbed with 20 mL of 500 mg / L phenol solution. Samples of the adsorbed solution were extracted at set time intervals (5, 10, 15, 20, 30, 40, 60, 80, 100, and 120 min), and the phenol content was determined by UV spectroscopy to calculate the adsorption capacity of the intercalated gangue-based surface molecularly imprinted adsorption material (the adsorption kinetic curve is shown in the attached figure). Figure 3 ).

[0056] 0.2g of intercalated gangue-based surface molecularly imprinted adsorption material, 0.2g of cetyltrimethylammonium bromide macromolecular intercalated gangue, and 0.2g of gangue were placed in a 20mL mixture of phenol, hydroquinone, and p-nitrophenol, where the mass concentration of each of the three in the mixture was 500 mg / L. Samples of the adsorbed solution were extracted within a set time of 60 minutes, and the contents of phenol, hydroquinone, and p-nitrophenol were determined by ultraviolet spectroscopy to calculate the selectivity of the adsorption material (the adsorption selectivity is shown in the attached figure). Figure 3 ).

[0057] The intercalated gangue-based surface molecularly imprinted adsorption material and the cetyltrimethylammonium bromide macromolecular intercalated gangue were filled into a fixed bed adsorption device (see Appendix Figure 4 ), where the adsorption column height was 3 cm. The operation time was set to 300 minutes with an influent flow rate of 2 ml / min. Subsequently, the adsorption material's effectiveness in removing phenols from the coal chemical wastewater was measured and evaluated.

[0058] Scanning electron microscopy (see Appendix Figure 1) observations clearly show that, compared to gangue, the surface pores of the gangue intercalated with cetyltrimethylammonium bromide macromolecules are significantly larger, the surface roughness increases, and multiple small platelets are attached. Furthermore, compared to gangue intercalated with cetyltrimethylammonium bromide macromolecules, the surface of the gangue-based surface molecularly imprinted adsorption material exhibits a distinct coating imprinting layer and numerous micropores.

[0059] By infrared spectroscopy analysis (see attached Figure 2 In a), the increase of HO, CO and C=O functional groups can be clearly observed, indicating that the modification of functional monomers and other substances has been successfully completed. In addition, the specific surface area and pore structure of molecular imprinting materials on the surface of coal gangue and intercalated coal gangue are compared and analyzed (see Appendix Figure 2 b and c in the figure), the results show that the number of micropores suitable for the size of phenol molecules on the surface of the modified intercalated coal gangue molecular imprinting material is significantly increased.

[0060] Adsorption selectivity analysis (see attached Figure 3 ) showed that compared with cetyltrimethylammonium bromide macromolecular intercalated coal gangue and ordinary coal gangue, the intercalated coal gangue-based surface molecular imprinting adsorption material had significant selectivity for phenol.

[0061] Example 2

[0062] Take 8g of 300-mesh coal gangue in a beaker, prepare dimethyl sulfoxide solution and water in a mass ratio of 9:1, add 200ml of dimethyl sulfoxide solution, stir at 70℃ for 20h, and the stirring speed is 500r / min; centrifuge at a speed of 4500r / min and a centrifugal time of 5min; then place the precipitate in a drying oven and dry it at 60℃ for 24h to obtain directly intercalated coal gangue.

[0063] Take 4 g of directly intercalated coal gangue and 100 ml of methanol, magnetically stir at 50°C for 24 hours with a stirring speed of 500 r / min; centrifuge at a speed of 5000 r / min and a centrifugal time of 5 minutes; pour off the upper solution, and finally dry at 70°C for 24 hours to obtain methanol twice intercalated coal gangue.

[0064] Take 4 g of methanol-intercalated coal gangue and mix it with 100 ml of a methanol solution of hexadecyltrimethylammonium bromide with a mass concentration of 30 mg / L. Place the two in a beaker and magnetically stir at 60°C for 20 hours with a stirring speed of 500 r / min. Centrifuge at a centrifugal speed of 5000 r / min and a centrifugal time of 5 minutes. Then wash the product repeatedly with ethanol solution, filter and dry it at 70°C for 24 hours to obtain hexadecyltrimethylammonium bromide macromolecule intercalated coal gangue.

[0065] 1.6 g of phenol, 0.8 g of hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue and 3.2 mL of methacrylic acid were dissolved in 25 mL of acetonitrile solvent, nitrogen was introduced for 3 minutes and then sealed, and magnetic stirring was carried out at 30°C for 1 hour at a stirring speed of 380 r / min; then 0.64 mL of ethylene glycol dimethacrylate and 0.16 g of azobisisobutyronitrile were added, nitrogen was introduced again for 3 minutes and then sealed, and magnetic stirring was carried out at 60°C for 24 hours at a stirring speed of 380 r / min. Phenol and methacrylic acid were modified near the pores of the intercalated coal gangue to obtain an imprinted product.

[0066] A methanol / acetic acid mixture (9:2) was used as the eluent to remove the phenol template molecules from the imprinted reaction product. The washed imprinted reaction product was dried in a vacuum freeze dryer for 14 hours to obtain a methacrylic acid intercalated coal gangue-based surface molecularly imprinted adsorption material.

[0067] A fixed-bed adsorption apparatus was filled with intercalated gangue-based surface molecularly imprinted adsorbent material and cetyltrimethylammonium bromide macromolecular intercalated gangue. The adsorption column height was 3 cm. The influent flow rate of coal chemical wastewater was 2 ml / min, and the operation time was set for 300 minutes. The removal efficiency of the adsorbent material for phenolic compounds in the coal chemical wastewater was then measured and evaluated.

[0068] Example 3

[0069] Take 9g of 350-mesh coal gangue in a beaker, prepare dimethyl sulfoxide solution and water in a mass ratio of 9:2, add 150ml of dimethyl sulfoxide solution, stir at 65℃ for 22h, and the stirring speed is 400r / min; centrifuge at a speed of 5000r / min and a centrifugal time of 5min; then place the precipitate in a drying oven and dry it at 65℃ for 22h to obtain directly intercalated coal gangue.

[0070] Take 4 g of directly intercalated coal gangue and 90 ml of methanol, magnetically stir at 55°C for 20 hours with a stirring speed of 400 r / min; centrifuge at a speed of 4800 r / min and a centrifugal time of 5 minutes; pour off the upper solution, and finally dry at 65°C for 22 hours to obtain methanol twice intercalated coal gangue.

[0071] Take 5g of methanol-intercalated coal gangue and mix it with 90ml of 25mg / L methanol solution of hexadecyltrimethylammonium bromide. Place the two in a beaker and stir magnetically at 55℃ for 22h with a stirring speed of 400r / min. Centrifuge at a centrifugal speed of 4000r / min and a centrifugal time of 4min. Then wash the product repeatedly with ethanol solution, filter and dry it at 70℃ for 22h to obtain hexadecyltrimethylammonium bromide macromolecule intercalated coal gangue.

[0072] Take 2g of phenol, 1g of hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue and 3mL of methacrylic acid and dissolve them in 30mL of acetonitrile solvent. After nitrogen is introduced for 5 minutes, it is sealed and magnetically stirred for 1.5 hours at 25°C with a stirring speed of 400r / min. Then add 0.5mL of ethylene glycol dimethacrylate and 0.18g of azobisisobutyronitrile, introduce nitrogen again for 4 minutes and seal, and magnetically stir for 23 hours at 65°C with a stirring speed of 400r / min. Phenol and methacrylic acid are modified near the pores of the intercalated coal gangue to obtain an imprinted product.

[0073] A methanol / acetic acid mixture (ratio 9:1.5) was used as the eluent to remove the phenol template molecules from the imprinted reaction product. The washed imprinted reaction product was dried in a vacuum freeze dryer for 12 hours to obtain a methacrylic acid intercalated coal gangue-based surface molecularly imprinted adsorption material.

[0074] A fixed-bed adsorption apparatus was filled with intercalated gangue-based surface molecularly imprinted adsorbent material and cetyltrimethylammonium bromide macromolecular intercalated gangue. The adsorption column height was 3 cm. The influent flow rate of coal chemical wastewater was 2 ml / min, and the operation time was set for 300 minutes. The removal efficiency of the adsorbent material for phenolic compounds in the coal chemical wastewater was then measured and evaluated.

[0075] Example 4

[0076] Take 10g of 250-mesh coal gangue in a beaker, prepare dimethyl sulfoxide solution and water in a mass ratio of 9:2, add 150ml of dimethyl sulfoxide solution, stir at 70℃ for 24h, and the stirring speed is 500r / min; centrifuge at a speed of 5000r / min and a centrifugal time of 4min; then place the precipitate in a drying oven and dry it at 60℃ for 24h to obtain directly intercalated coal gangue.

[0077] Take 3 g of directly intercalated coal gangue and 100 ml of methanol, magnetically stir at 55°C for 22 hours at a stirring speed of 400 r / min; centrifuge at a centrifugal speed of 4800 r / min for 3 minutes; pour off the upper solution, and finally dry at 70°C for 20 hours to obtain methanol twice intercalated coal gangue.

[0078] Take 3g of methanol-intercalated coal gangue and mix it with 100ml of methanol solution of hexadecyltrimethylammonium bromide with a mass concentration of 25mg / L. Place the two in a beaker and magnetically stir at 60℃ for 24h with a stirring speed of 480r / min. Centrifuge at a centrifugal speed of 4500r / min and a centrifugal time of 3min. Then wash the product repeatedly with ethanol solution, filter and dry it at 66℃ for 20h to obtain hexadecyltrimethylammonium bromide macromolecule intercalated coal gangue.

[0079] Take 1g of phenol, 0.5g of hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue and 2mL of acrylic acid and dissolve them in 35mL of acetonitrile solvent. After nitrogen is introduced for 7 minutes, it is sealed and magnetically stirred for 2h at 20℃ with a stirring speed of 420r / min. Then add 0.6mL of ethylene glycol dimethacrylate and 0.1g of azobisisobutyronitrile, introduce nitrogen again for 5 minutes and seal, and magnetically stir for 22h at 60℃ with a stirring speed of 420r / min. Phenol and acrylic acid are modified near the pores of the intercalated coal gangue to obtain an imprinted product.

[0080] A methanol / acetic acid mixture (9:2) was used as the eluent to remove the phenol template molecules from the imprinted reaction product. The washed imprinted reaction product was dried in a vacuum freeze dryer for 14 hours to obtain an acrylic acid-intercalated coal gangue-based surface molecularly imprinted adsorption material.

[0081] 0.2 g of acrylic acid-intercalated gangue-based surface molecularly imprinted adsorption material and 0.2 g of acrylic acid-intercalated gangue-based surface molecularly imprinted adsorption material were placed in 20 mL of a 500 mg / L phenol solution for adsorption. Samples of the adsorbed solution were extracted within a set time of 60 minutes, and the phenol content was measured by UV spectroscopy to calculate the selectivity of the adsorption material.

[0082] Example 5

[0083] Take 8g of 300-mesh coal gangue in a beaker, prepare dimethyl sulfoxide solution and water in a mass ratio of 9:1, add 120ml of dimethyl sulfoxide solution, stir at 60℃ for 24h, and the stirring speed is 400r / min; centrifuge at a speed of 5000r / min and a centrifugal time of 5min; then place the precipitate in a drying oven and dry it at 70℃ for 20h to obtain directly intercalated coal gangue.

[0084] Take 4 g of directly intercalated coal gangue and 100 ml of methanol, stir magnetically at 60°C for 20 hours at a stirring speed of 450 r / min; centrifuge at a centrifugal speed of 5000 r / min for 4 minutes; pour off the upper solution, and finally dry at 60°C for 24 hours to obtain methanol twice intercalated coal gangue.

[0085] Take 5g of methanol-intercalated coal gangue and mix it with 90ml of methanol solution of hexadecyltrimethylammonium bromide with a mass concentration of 24mg / L. Place the two in a beaker and stir magnetically at 50℃ for 20h with a stirring speed of 450r / min. Centrifuge at a centrifugal speed of 4500r / min and a centrifugal time of 3min. Then wash the product repeatedly with ethanol solution, filter and dry it at 65℃ for 20h to obtain hexadecyltrimethylammonium bromide macromolecule intercalated coal gangue.

[0086] 3 g of phenol, 1 g of hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue and 9 mL of methacrylamide were dissolved in 35 mL of acetonitrile solvent, nitrogen was introduced for 7 minutes and then sealed. The mixture was magnetically stirred at 25°C for 1 hour at a stirring speed of 420 r / min. Then 1.5 mL of ethylene glycol dimethacrylate and 0.45 g of azobisisobutyronitrile were added, nitrogen was introduced again for 5 minutes and then sealed. The mixture was magnetically stirred at 70°C for 22 hours at a stirring speed of 420 r / min. Phenol and methacrylamide were modified near the pores of the intercalated coal gangue to obtain an imprinted product.

[0087] A methanol / acetic acid mixture (9:1) was used as the eluent to remove the phenol template molecules from the imprinted reaction product. The washed imprinted reaction product was dried in a vacuum freeze dryer for 12 hours to obtain a methacrylamide-intercalated coal gangue-based surface molecularly imprinted adsorption material.

[0088] 0.2 g of a methacrylamide-intercalated gangue-based surface molecularly imprinted adsorption material and 0.2 g of a methacrylamide-intercalated gangue-based surface molecularly imprinted adsorption material were placed in 20 mL of a 500 mg / L phenol solution for adsorption. Samples of the adsorbed solution were extracted within 60 minutes, and the phenol content was determined by UV spectroscopy to calculate the selectivity of the adsorption material.

[0089] Table 1 Adsorption effect of gangue-based surface molecularly imprinted adsorption materials prepared in Examples 1-5 on phenols

[0090]

[0091] From Table 1 above, it can be seen that the gangue-based surface molecularly imprinted adsorption material prepared in Example 1 has the best selective adsorption effect on phenols, wherein the adsorption capacities of p-phenol, hydroquinone and p-nitrophenol are 73.55 mg / g, 41.32 mg / g and 36.18 mg / g respectively.

[0092] Advantages of the present invention:

[0093] (1) Optimized intercalation process and imprinting effect: The three-step intercalation process significantly increases the interlayer spacing of the material, significantly improving its adsorption capacity. Using this enhanced structure as a carrier for molecular imprinting, the adsorption efficiency of phenol pollutants was greatly improved, demonstrating excellent removal effect.

[0094] (2) Excellent selective adsorption performance: The intercalated coal gangue after molecular imprinting treatment showed excellent selective adsorption ability for mixed solutions of various phenols such as phenol, hydroquinone and p-nitrophenol, showing higher application value and broad application prospects.

[0095] (3) High-efficiency separation capability in complex environments: The intercalated gangue-based molecularly imprinted adsorption material can still achieve specific adsorption of phenol in complex coal chemical wastewater systems, ensuring the precise separation and efficient recovery of phenol. This technology provides an efficient and environmentally friendly solution for treating complex wastewater systems, helping to promote the development of green chemical processes.

[0096] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing an intercalated gangue-based surface molecularly imprinted adsorption material, characterized in that: include: Using coal gangue as raw material, an intercalation reaction occurs in a solution containing an intercalation agent, and intercalated coal gangue is formed through centrifugal separation and drying; Using intercalated coal gangue as a carrier, phenol and methacrylic acid were added to acetonitrile solvent under an inert atmosphere for a preliminary reaction, and then a cross-linking agent and an initiator were added to carry out a surface imprinting reaction to obtain an imprinting reaction product. The imprinting reaction product is treated to obtain an intercalated coal gangue-based surface molecular imprinting adsorption material; The intercalation reaction includes a direct intercalation reaction of dimethyl sulfoxide, a double intercalation reaction of methanol, and a macromolecular intercalation reaction of hexadecyltrimethylammonium bromide; the coal gangue needs to be ground to 200 mesh to 350 mesh and calcined at 700°C to 800°C.

2. The method for preparing the intercalated gangue-based surface molecularly imprinted adsorption material according to claim 1, characterized in that: The intercalated coal gangue is mixed with a dimethyl sulfoxide intercalation agent solution, magnetically stirred under heating conditions, and then centrifuged and dried to obtain directly intercalated coal gangue; Direct intercalation of coal gangue and methanol solution, magnetic stirring under heating conditions, centrifugal separation, pouring the upper solution, to obtain methanol twice intercalated coal gangue; The methanol twice intercalated coal gangue is mixed with a methanol solution of hexadecyltrimethylammonium bromide, the two are stirred evenly, and the product is repeatedly washed with an ethanol solution, and the hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue is obtained after filtration.

3. The method for preparing the intercalated gangue-based surface molecularly imprinted adsorption material according to claim 2, characterized in that: The gangue and dimethyl sulfoxide solution are stirred at 60°C to 70°C for 20h to 24h at a stirring speed of 300 r / min to 500 r / min; the centrifugal speed is 4000 r / min to 5000 r / min, and the centrifugal time is 3min to 5min. Finally, the mixture is dried at 60°C to 70°C for 20h to 24h to obtain directly intercalated gangue. The addition ratio of gangue to dimethyl sulfoxide solution is 8g to 10g: 100ml to 200ml. Direct intercalation gangue and methanol are magnetically stirred at 50°C to 60°C for 20h to 24h, then centrifuged at a speed of 4000 r / min to 5000 r / min for 3min to 5min, and finally dried at 60°C to 70°C for 20h to 24h to obtain methanol twice intercalated gangue; wherein the dosage ratio of direct intercalation gangue to methanol is 3g to 5g:80ml to 100ml; The methanol-intercalated coal gangue was mixed with a methanol solution of hexadecyltrimethylammonium bromide, magnetically stirred at 50°C to 60°C for 20h to 24h, then centrifuged at a speed of 4000 r / min to 5000 r / min for 3min to 5min, and finally dried at 60°C to 70°C for 20h to 24h to obtain hexadecyltrimethylammonium bromide macromolecular intercalated coal gangue; The ratio of methanol twice intercalated coal gangue to methanol solution of hexadecyltrimethylammonium bromide is 3g~5g:80~100ml.

4. The method for preparing the intercalated gangue-based surface molecularly imprinted adsorption material according to claim 2, characterized in that: The mass ratio of dimethyl sulfoxide solution to water is 9:1~9:2; the concentration of hexadecyltrimethylammonium bromide methanol solution is 20 mg / L~30 mg / L.

5. The method for preparing the intercalated gangue-based surface molecularly imprinted adsorption material according to claim 1, characterized in that: During the preliminary reaction process, the mass ratio of intercalated coal gangue, phenol and methacrylic acid is (1-3): (0.5-1): (2-9); the reaction temperature is controlled at 20°C to 30°C, and the reaction time is 1h to 2h.

6. The method for preparing the intercalated gangue-based surface molecularly imprinted adsorption material according to claim 1, characterized in that: During the surface imprinting reaction process: the crosslinking agent is ethylene glycol dimethacrylate, the initiator is azobisisobutyronitrile; the mass ratio of ethylene glycol dimethacrylate and azobisisobutyronitrile is (0.5~1.5): (0.1~0.45); the reaction temperature is controlled at 60℃~70℃, and the reaction time is 22h~24h.

7. The method for preparing the intercalated gangue-based surface molecularly imprinted adsorption material according to claim 1, characterized in that: The imprinting reaction product is processed to obtain the intercalated gangue-based surface molecularly imprinted adsorption material, specifically: The imprinted reaction product is washed with a mixture of methanol and acetic acid as an eluent to remove the phenol template molecules on the imprinted reaction product; the washed imprinted reaction product is dried to obtain an intercalated coal gangue-based surface molecular imprinted adsorption material.

8. The method for preparing the intercalated gangue-based surface molecularly imprinted adsorption material according to claim 7, characterized in that: The volume ratio of methanol to acetic acid is 9:1 to 9:2, and the washed imprinted reaction product is dried for 12 h to 14 h.

9. An intercalated gangue-based surface molecularly imprinted adsorption material, characterized in that: The method according to any one of claims 1 to 8 is used for preparation.

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