Graphyne-based supermolecular oil-water separation material, preparation method and application thereof

Abstract

The application belongs to the technical field of oil-water separation materials, and provides a graphdiyne-based supramolecular oil-water separation material, a preparation method and application thereof. The method comprises the following steps: impregnating wood after processing with an organic solvent A; dissolving hexaethynylbenzene monomers in a solution B to prepare a monomer solution; stacking the impregnated wood and copper foils in the mode of "copper foil-wood-copper foil", and placing them in the monomer solution to react in dark conditions; and cleaning and drying the reacted wood to obtain the graphdiyne-based supramolecular oil-water separation material. The application composites graphdiyne and natural wood, adopts wood surface modification and organic solvent impregnation-in-situ growth, realizes in-situ controllable growth of graphdiyne on the wood surface, and successfully prepares the graphdiyne-based supramolecular oil-water separation material. The material has high separation efficiency, high flux, high selectivity and stability, and the wettability is adjustable, and can be widely used in oil-water separation of industrial wastewater containing oil, domestic sewage and offshore oil leakage.

Description

Technical Field

[0001] This invention belongs to the field of oil-water separation materials technology, and particularly relates to a graphdiyne-based supramolecular oil-water separation material, its preparation method, and its application. Background Technology

[0002] Pollution problems such as oily industrial wastewater, domestic sewage, and marine oil spills pose serious threats to ecosystems and human health. Developing efficient, low-cost, and environmentally friendly oil-water separation materials has become a current research hotspot.

[0003] Currently, common oil-water separation methods include centrifugation, adsorption, flotation, and membrane separation. Among these, membrane separation has attracted much attention due to its advantages such as simple operation, low energy consumption, and high separation efficiency. However, current oil-water separation membranes still face several bottlenecks that urgently need to be addressed: the membrane pores are prone to clogging during use, reducing fluid flux; large-area, high-quality preparation and non-destructive transfer of the membrane are difficult; and the membrane's mechanical strength is poor, making it susceptible to damage under long-term pressure, affecting stability and service life. These problems severely limit the widespread application of oil-water separation membranes in practical applications. Therefore, there is an urgent need to develop new high-performance separation membrane materials that can improve separation efficiency while also considering material strength and stability.

[0004] Natural wood is a widely available, renewable, and biodegradable porous biomass material. Its interior contains oriented, interconnected micro- and nano-channels arranged along the growth direction, providing a natural, low-resistance path for fluid transport. Secondly, wood has a high specific surface area and abundant hydroxyl groups, providing ample sites for surface functional group modification in separation membranes, facilitating the uniform dispersion and stable existence of functional groups. Furthermore, wood itself possesses a certain degree of hydrophilicity, which can be controlled to achieve selective wetting and separation. In recent years, Graphdiyne (GDY), as a novel two-dimensional carbon allotrope, has shown great application potential and broad prospects in many fields due to its regular and uniformly distributed natural channels, intrinsically tunable hydrophilic / hydrophobic properties, excellent chemical / mechanical stability, and non-uniform surface charge distribution. In particular, Graphdiyne possesses atomic-level anchoring sites and molecular-level channels, enabling precise sieving of oil molecules, while its hydrophilic / hydrophobic surface facilitates oil adsorption and permeation, thus possessing great potential for constructing highly selective and high-throughput separation membranes.

[0005] Combining wood with graphynylene to construct graphynylene-based supramolecular oil-water separation materials holds promise for achieving highly selective and long-lasting oil-water separation capabilities. Currently, research on graphynylene-based supramolecular oil-water separation materials is lacking. Therefore, fully leveraging the synergistic advantages of graphynylene and wood in oil-water separation to develop efficient and stable oil-water separation membranes is of significant research importance. To this end, this invention proposes a graphynylene-based supramolecular oil-water separation material, its preparation method, and its applications. Summary of the Invention

[0006] The purpose of this invention is to provide a graphdiyne-based supramolecular oil-water separation material, its preparation method, and its application, thereby addressing the problems mentioned in the background art.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing a graphityne-based supramolecular oil-water separation material includes the following steps:

[0009] Step 1: Select low-density, high-porosity wood, process it into the preset shape and size, and then soak it in organic solvent A;

[0010] Step 2: Dissolve the hexaethynylbenzene monomer in solution B to prepare a monomer solution with a concentration of 0.1-300 mg / mL;

[0011] Step 3: Stack the wood treated in Step 1 and copper foil in the manner of "copper foil-wood-copper foil", and put them into the monomer solution (10-100 mL) prepared in Step 2. React in the dark at 0-150 ℃ for 24-144 h.

[0012] Step 4: Remove the reacted wood, wash it with ethanol, and dry it to obtain graphityne-based supramolecular oil-water separation material.

[0013] Furthermore, in step 1, the wood is any one or a combination of natural wood, delignified wood, de-hemicellulose wood, and oxidized wood.

[0014] Furthermore, in step 1, organic solvent A is any one of dichloromethane, chloroform, ethylene glycol, ethyl acetate, glycerol, propanol, butanol, hexanediol, N,N-dimethylformamide, acetone, toluene, pyridine, triethylamine, diethylamine, ethanol, and tetrahydrofuran.

[0015] Furthermore, in step 1, the impregnation method is vacuum impregnation, the impregnation pressure is -0.09 MPa, and the impregnation time is 0.5-4 h.

[0016] Furthermore, in step 2, solution B is at least one of dichloromethane, chloroform, ethylene glycol, ethyl acetate, glycerol, propanol, butanol, hexanediol, N,N-dimethylformamide, acetone, toluene, pyridine, triethylamine, diethylamine, ethanol, and tetrahydrofuran.

[0017] Furthermore, in step 2, the hexaethynylbenzene monomer is replaced with a methyl-substituted, hydrogen-substituted, or halogen-substituted hexaethynylbenzene monomer.

[0018] Furthermore, in step 3, the copper foil is replaced with a metal salt solution of 0.01-100 mg / mL, which is any one of monovalent copper salt, divalent copper salt, or palladium salt.

[0019] Furthermore, in step 4, the temperature of the ethanol is 30-60 ℃.

[0020] Furthermore, in step 4, the drying method is any one of freeze drying, supercritical drying, solvent displacement drying, and air drying.

[0021] A graphdiyne-based supramolecular oil-water separation material prepared according to the above-described preparation method is disclosed. In this material, the graphdiyne can grow on the surface of wood cell walls, between microfibrils, and within cellulose lattices, exhibiting multi-scale structural characteristics. The graphdiyne in the material can be a single layer, few layers, nanosheet array, or a three-dimensional porous structure. The wettability of the material can be selectively controlled based on the type of hexaethynylbenzene monomer, the growth mode of the graphdiyne, and its microstructure.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention combines graphdiyne with natural wood, synergistically leveraging the advantages of both. Through wood surface modification and organic solvent impregnation-in-situ growth, graphdiyne-based supramolecular oil-water separation materials are successfully prepared. These materials possess high separation efficiency, high throughput, high selectivity, and stability, and their wettability is adjustable. This effectively overcomes the application bottlenecks of existing oil-water separation materials, such as insufficient efficiency, and can be widely used for oil-water separation in scenarios involving oily industrial wastewater, domestic sewage, and marine oil spills. Attached Figure Description

[0024] Figure 1 The images show scanning electron microscope (SEM) images and water contact angles of the graphdiyne-based supramolecular oil-water separation material obtained in Example 1; where (a) is a scanning electron microscope image of the material obtained in Example 1, and (b) is the water contact angle of the material obtained in Example 1.

[0025] Figure 2The images show scanning electron microscope (SEM) images and water contact angles of the graphdiyne-based supramolecular oil-water separation material obtained in Example 2; where (a) is a scanning electron microscope image of the material obtained in Example 2, and (b) is the water contact angle of the material obtained in Example 2.

[0026] Figure 3 The images show scanning electron microscope (SEM) images and water contact angles of the graphdiyne-based supramolecular oil-water separation material obtained in Example 3; where (a) is a scanning electron microscope image of the material obtained in Example 3, and (b) is the water contact angle of the material obtained in Example 3.

[0027] Figure 4 This is a test diagram for oil-in-water separation.

[0028] Figure 5 The data from the performance testing process is separated for this example. Detailed Implementation

[0029] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this invention, the technical solution of this invention is described in detail below, but this should not be construed as limiting the scope of implementation of this invention. In this invention, materials, reagents, or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0030] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0031] Example 1: Preparation of a graphdiyne-based supramolecular oil-water separation material;

[0032] Step 1: Select a natural balsa wood tangential board with a thickness of 0.4 mm, cut it into a rectangle of 1.5 cm × 1.5 cm, put it into 10 mL of pyridine, and soak it at -0.09 MPa for 0.5 h;

[0033] Step 2: Dissolve 15 mg of hexaethynylbenzene monomer in 15 mL of pyridine.

[0034] Step 3: Stack the wood treated in Step 1 and copper foil in the manner of "copper foil-wood-copper foil", place them in the solution prepared in Step 2, and react at 25 ℃ for 96 h in the dark.

[0035] Step 4: Remove the reacted wood, wash it twice with 50 °C ethanol, and air dry it to obtain graphityne-based supramolecular oil-water separation material.

[0036] like Figure 1 As shown in (a), graphdiene was successfully loaded onto balsa wood tangentially, exhibiting multi-scale structural features. These graphdiene structures grow on the surface of wood cell walls, providing a structural basis for the material's properties. Figure 1As shown in (b), the material obtained in Example 1 exhibits hydrophilic properties, with a water contact angle reaching 69.8°. The material obtained in Example 1 underwent an oil-in-water (n-hexane, oil concentration 9.1%) separation test. Figure 4 The time required to separate 15 mL of emulsion and the concentration of the filtrate are as follows: Figure 5 As shown, the flux calculated according to formula (1) is 3000 L / m. 2 / h, the separation efficiency is calculated to be 90% based on the concentrations of the permeate and the stock solution.

[0037] Example 2: Preparation of a graphdiyne-based supramolecular oil-water separation material;

[0038] Step 1: Select a natural poplar tangential board with a thickness of 0.4 mm, cut it into a rectangle of 1.5 cm × 1.5 cm, put it into 10 mL of dichloromethane, and soak it at -0.09 MPa for 3 h;

[0039] Step 2: Dissolve 15 mg of hexaethynylbenzene monomer in 15 mL of a mixed solution of dichloromethane and pyridine (the volume ratio of dichloromethane to pyridine is 10:1).

[0040] Step 3: Stack the wood treated in Step 1 and copper foil in the manner of "copper foil-wood-copper foil", place them in the solution prepared in Step 2, and react at 25 ℃ for 48 h in the dark.

[0041] Step 4: Remove the reacted wood, wash it twice with 50 °C ethanol, and air dry it to obtain graphityne-based supramolecular oil-water separation material.

[0042] like Figure 2 As shown in (a), graphdiene was successfully loaded onto poplar tangential plates, forming multi-scale structures with three-dimensional porous features. These structures are distributed on the cell wall surface of the wood, demonstrating the growth characteristics of graphdiene on different wood substrates. Figure 2 As shown in (b), the material obtained in Example 2 exhibits hydrophilic properties, with a water contact angle reaching 67.8°. The material obtained in Example 2 underwent an oil-in-water (dichloromethane, concentration 9.1%) separation test. Figure 4 The time required to separate 15 mL of emulsion and the concentration of the filtrate are as follows: Figure 5 As shown, the flux calculated according to formula (1) is 10000 L / m. 2 The separation efficiency was calculated to be 96% based on the concentrations of the permeate and the stock solution per h.

[0043] Example 3: Preparation of a graphdiyne-based supramolecular oil-water separation material;

[0044] Step 1: Select a 0.4 mm thick natural balsa wood cross-section board, cut it into 1.5 cm × 1.5 cm rectangles, place it in 10 mL of tetrahydrofuran, and immerse it at -0.09 MPa for 0.5 h;

[0045] Step 2: Dissolve 15 mg of hexaethynylbenzene monomer in 15 mL of a mixed solution of tetrahydrofuran and pyridine (the volume ratio of tetrahydrofuran to pyridine is 10:1).

[0046] Step 3: Stack the wood treated in Step 1 and copper foil in the manner of "copper foil-wood-copper foil", place them in the solution prepared in Step 2, and react at 25 ℃ for 24 h in the dark.

[0047] Step 4: Remove the reacted wood, wash it twice with 50 °C ethanol, and air dry it to obtain graphityne-based supramolecular oil-water separation material.

[0048] like Figure 3 As shown in (a), graphdiene was successfully loaded onto a balsa wood cross-section, exhibiting multi-layer stacking, demonstrating the growth of graphdiene on different wood cross-sections (cross-sections). Figure 3 As shown in (b), the material obtained in Example 3 exhibits hydrophilic properties, with a water contact angle reaching 68.5°. An oil-in-water (vegetable oil, concentration 9.1%) separation test was performed on the material obtained in Example 3. Figure 4 The time required to separate 15 mL of emulsion and the concentration of the filtrate are as follows: Figure 5 As shown, the flux calculated according to formula (1) is 3000 L / m. 2 The separation efficiency was calculated to be 93% based on the concentrations of the permeate and the stock solution per h.

[0049] The specific procedures for the above-mentioned oil-in-water separation test are as follows:

[0050] A graphitic acetylene-based supramolecular oil-water separation material (membrane) was fixed between two glass tubes with an inner diameter of 15 mm. The openings of the two glass tubes were fixed with duckbill clamps. The membrane was moistened with deionized water or oil (n-hexane, dichloromethane, vegetable oil, etc.). At 2.0 bar, a mixture of oil and water (oil-water mass ratio = 1:10 or 10:1) was poured onto the water-pre-wetted membrane surface. The oil-water separation was observed, the separation time was recorded, and the filtrate was collected. The oil-water separation test was repeated 5 times, and the average value of the 5 tests was taken as the experimental result.

[0051] The separation flux F is calculated using formula (1):

[0052] F=V / (S×t)(1;

[0053] Where V is the filtrate volume (mL) and S is the effective separation area (cm²). 2 ), where t is the separation time (s).

[0054] The separation efficiency η is calculated using formula (2):

[0055] η = (C2-C1) / C2×100(2;

[0056] Wherein, C1 and C2 represent the concentrations of water or oil in the permeate and the original solution, respectively.

[0057] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for preparing a graphdiyne-based supramolecular oil-water separation material, characterized in that, Includes the following steps: Step 1: Select wood, process it into the preset shape and size, and then soak it in organic solvent A; Step 2: Dissolve the hexaethynylbenzene monomer in solution B to prepare a monomer solution with a concentration of 0.1-300 mg / mL; Step 3: Stack the wood treated in Step 1 and copper foil in the manner of "copper foil-wood-copper foil", place them in the monomer solution prepared in Step 2, and react them in the dark at 0-150 ℃ for 24-144 h. Step 4: Remove the reacted wood, wash it with ethanol, and dry it to obtain graphityne-based supramolecular oil-water separation material.

2. The preparation method according to claim 1, characterized in that, In step 1, the wood is any one or a combination of natural wood, delignified wood, de-hemicellulose wood, and oxidized wood.

3. The preparation method according to claim 1, characterized in that, In step 1, organic solvent A is any one of dichloromethane, chloroform, ethylene glycol, ethyl acetate, glycerol, propanol, butanol, hexanediol, N,N-dimethylformamide, acetone, toluene, pyridine, triethylamine, diethylamine, ethanol, and tetrahydrofuran.

4. The preparation method according to claim 1, characterized in that, In step 1, the impregnation method is vacuum impregnation, the impregnation pressure is -0.09 MPa, and the impregnation time is 0.5-4 h.

5. The preparation method according to claim 1, characterized in that, In step 2, solution B is at least one of dichloromethane, chloroform, ethylene glycol, ethyl acetate, glycerol, propanol, butanol, hexanediol, N,N-dimethylformamide, acetone, toluene, pyridine, triethylamine, diethylamine, ethanol, and tetrahydrofuran.

6. The preparation method according to claim 1, characterized in that, In step 2, the hexaethynylbenzene monomer is replaced with a methyl-substituted, hydrogen-substituted, or halogen-substituted hexaethynylbenzene monomer.

7. The preparation method according to claim 1, characterized in that, In step 3, the copper foil is replaced with a metal salt solution of 0.01-100 mg / mL, which can be any one of monovalent copper salt, divalent copper salt, or palladium salt.

8. The preparation method according to claim 1, characterized in that, In step 4, the temperature of the ethanol is 30-60 ℃.

9. The preparation method according to claim 1, characterized in that, In step 4, the drying method is any one of freeze drying, supercritical drying, solvent displacement drying, and air drying.

10. A graphdiyne-based supramolecular oil-water separation material prepared by the preparation method according to any one of claims 1-9.

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