Preparation method and application of an ordered mesoporous-microporous carbon composite material

Abstract

The present application provides a preparation method and application of an ordered mesoporous-microporous carbon composite material. The preparation method includes: (1) infiltrating a foaming material into a mixed solution containing phenolic resin, a silicon source, and a nonionic surfactant, and drying to obtain a first matrix; (2) mixing the first matrix with a phosphate compound and reacting to obtain a second matrix; (3) calcining the second matrix under an inert gas to obtain a third matrix; (4) reacting the third matrix with a hydrofluoric acid-containing solution to generate an ordered mesoporous-microporous carbon composite material. The ordered mesoporous-microporous carbon composite material prepared in the present application is corrosion-resistant, has a large specific surface area, a high porosity, good adsorption performance, and a low cost, and has excellent mechanical stability and chemical stability, and can adsorb, separate, and rapidly desorb organic pollutants in high-concentration wastewater.

Description

Technical Field

[0001] The present application relates to the technical field of new material synthesis, and specifically relates to a preparation method and application of an ordered mesoporous-microporous carbon composite material. Background Art

[0002] For the treatment of organic matter, i.e., COD, in high-salt wastewater from coal chemical industry, processes such as biochemical systems, ozone systems, activated carbon adsorption, etc. are usually adopted. However, there is still some COD that cannot be removed, resulting in 10 - 15% of miscellaneous salts being generated in the subsequent salt separation and crystallization section. According to relevant laws and regulations, this miscellaneous salt is disposed of as hazardous waste, and the disposal cost is 3000 - 5000 yuan / ton, bringing a relatively large economic burden to the enterprise.

[0003] The main COD (organic characteristic pollutants) in high-salt wastewater from coal chemical industry are nearly 40 kinds such as humin, fulvic acid, dimethylpyridine, acetophenone, glutaraldehyde, citric anhydride, chloro(methyl)thiocyanate, N-ethylacetamide, etc.; this organic matter has the characteristics of complex composition, small relative molecular mass, high biological toxicity, and great degradation difficulty, and environmental protection treatment is very difficult.

[0004] Ordered mesoporous carbon materials have the characteristics of high specific surface area, high porosity, and corrosion resistance, and the composition and pore size of this material can be flexibly adjusted. Therefore, when adsorbing and separating substances with different molecular structures and different molecular weights, it has great advantages in terms of selectivity and desorption. These characteristics of ordered mesoporous carbon materials show great application prospects in the adsorption and separation, efficient treatment, recycling, and cost saving of organic matter in high-salt wastewater from coal chemical industry.

[0005] There are many existing methods for synthesizing mesoporous carbon materials, mainly including: hard template method, soft template method, catalytic activation method, organic gel carbonization method, etc. However, the disadvantages of the hard template method are that the operation process is complicated, the cost is relatively high, and the stability of the obtained mesoporous carbon material is relatively poor; the soft template method is relatively simple in process, and the pore size and mesoporous structure are easy to control. The disadvantage is that the raw materials used have relatively high costs and are often toxic, which is not conducive to environmental protection; the catalytic activation method is not conducive to controlling the mesoporous structure, pore distribution, and pore size, and the catalyst is easy to remain; the disadvantage of the organic gel carbonization method is that the pore size distribution is large, the carbonization is relatively complex, and it is not easy to be commercially promoted. Summary of the Invention

[0006] In view of the above existing technical limitations, the present application proposes a new preparation method of an ordered mesoporous-microporous carbon composite material, which overcomes the deficiencies and defects mentioned in the background art.

[0007] To achieve the above object, the present application adopts the following technical solutions:

[0008] The inventive point of this application is to provide a method for preparing an ordered mesoporous-microporous carbon composite material, which includes: (1) infiltrating a foaming material into a mixed solution containing phenolic resin, silicon source and non-ionic surfactant, and drying to obtain a first matrix; (2) mixing the first matrix with a phosphate compound and reacting to obtain a second matrix; (3) calcining the second matrix under an inert gas to obtain a third matrix; (4) reacting the third matrix with a hydrofluoric acid-containing solution to generate an ordered mesoporous-microporous carbon composite material.

[0009] Optionally, the mass ratio of the foaming material, phenolic resin, silicon source and non-ionic surfactant is: (2-4):(19.2-24):(3-5):(4-8).

[0010] Optionally, the parameters of the foaming material are: 45-60 PPI, and the surface hardness is 40-65 N.

[0011] Optionally, the foaming material includes a composite material obtained by grafting or intercalating polyurethane.

[0012] Optionally, in step (1), the drying temperature is 80-150 °C; the drying time is ≥20 h.

[0013] Optionally, in step (1), it is first dried at 80-100 °C for ≥20 h, and then dried at 130-170 °C for ≥20 h. Optionally, in step (2), the reaction temperature is 160-180 °C, and the time is 5-10 h.

[0014] Optionally, the mass ratio of the amount of the phosphate compound added to the foaming material is: (8-10):(2-4).

[0015] Optionally, in step (3), the calcination conditions are: temperature 500-600 °C, time 2-5 h.

[0016] Optionally, the mass ratio of the amount of the hydrofluoric acid-containing solution added to the silicon source is: (4-6):(3-5).

[0017] Another inventive point of this application is to provide an ordered mesoporous-microporous carbon composite material prepared by the preparation method described above.

[0018] Optionally, the pore diameter of the ordered mesoporous-microporous carbon composite material is 0.2-2.5 nm; the specific surface area is 1100-1500 m 2 / g; the porosity is 75-85%.

[0019] Another inventive point of this application is to provide an application of the ordered mesoporous-microporous carbon composite material described above in removing COD from concentrated coal chemical brine.

[0020] Compared with the prior art, this application has the following beneficial effects:

[0021] (1) In this application, a mesoporous carbon matrix material is self-assembled through the coordinated reaction mechanism of phenolic resin solution and foaming material to effectively control the morphology, structure, and skeleton of the material. Subsequently, a polyhedral material with rich pores is obtained by utilizing the property of phosphate compounds to selectively eliminate polyurethane, and then a hollow carbon-silica polyhedral composite material is obtained by using a carbonization process. Finally, the silica component is removed to ultimately obtain an ordered mesoporous-microporous carbon composite material.

[0022] (2) The raw materials have a wide source, the process flow is short, and the reaction temperature is easy to control. The structure of the composite material can be freely controlled, the self-assembly process is simple, and the raw materials are safe and environmentally friendly. It can systematically solve the shortcomings of traditional processes and can be used for industrial production and preparation.

[0023] (3) The prepared ordered mesoporous-microporous carbon composite material is corrosion-resistant, has a large specific surface area, a high porosity, good adsorption performance, and a low cost. It has excellent mechanical stability and chemical stability, can adsorb, separate, and rapidly desorb organic pollutants in high-concentration wastewater, and has a long service life. Description of the Drawings

[0024] Figure 1 SEM images of the foamed polyurethane, the first matrix, the second matrix, the third matrix, and the ordered mesoporous-microporous carbon composite material during the preparation process of Test Example 1 of this application;

[0025] Figure 2 FT-IR spectra of various substances during the preparation process of Test Example 1 of this application; a phenolic resin; b the second matrix; c triblock polymer F127; d foamed polyurethane;

[0026] Figure 3 Thermogravimetric curves of various substances during the preparation process of Test Example 1 of this application; a phenolic resin; b the second matrix; c triblock polymer F127; d foamed polyurethane;

[0027] Figure 4 SEM image of the ordered mesoporous-microporous carbon composite material prepared in Test Example 2 of this application;

[0028] Figure 5 SEM image of the ordered mesoporous-microporous carbon composite material prepared in Test Example 3 of this application;

[0029] Figure 6 On-site photo of the product prepared in Test Example 2 of this application for removing COD from high-salt wastewater in coal chemical industry; the wastewater source is the concentrate of high-pressure reverse osmosis RO. The color comparison between the wastewater (inlet water) and the treated effluent. The COD in the wastewater causes the color to turn yellow and have an odor, while the treated effluent is clear and transparent and has no odor. Detailed Description of the Invention

[0030] To make the objectives, technical solutions and advantages of this application clearer, the following provides a further detailed description of this application. However, it should be understood that the description herein is only used to explain this application and is not used to limit the scope of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The reagents and instruments used herein are all commercially available, and the characterization means involved can refer to the relevant descriptions in the prior art, which will not be elaborated herein.

[0032] To further understand this application, the following provides a further detailed description of this application in combination with the best embodiments.

[0033] Example 1

[0034] This example provides a method for preparing an ordered mesoporous-microporous carbon composite, including: (1) infiltrating a foaming material into a mixed solution containing phenolic resin, silicon source and non-ionic surfactant, drying to obtain a first matrix; (2) mixing the first matrix with a phosphate compound and reacting to obtain a second matrix; (3) calcining the second matrix under an inert gas to obtain a third matrix; (4) reacting the third matrix with a hydrofluoric acid-containing solution to generate an ordered mesoporous-microporous carbon composite.

[0035] The mass ratio of the foaming material, phenolic resin, silicon source and non-ionic surfactant is: (2-4):(19.2-24):(3-5):(4-8).

[0036] The mixed solution containing phenolic resin, silicon source and non-ionic surfactant is obtained by mixing a phenolic resin solution and a non-ionic surfactant solution and then adding a silicon source.

[0037] The phenolic resin solution is obtained by reacting phenol and aqueous formaldehyde solution under alkaline conditions or can also be purchased from the market.

[0038] Among them, the addition amount of phenol is 12-15 parts; the addition amount of aqueous formaldehyde solution is 20-25 parts (concentration 30-40%).

[0039] At a temperature of 45 °C, 12-15 parts by mass of phenol with a concentration of 99% is dissolved in an alkaline aqueous solution (an aqueous solution with 1 part by mass and pH = 12), and stirred for 20 minutes; then 20-25 parts by mass of formaldehyde aqueous solution (concentration 35%) is added, and gradually heated to a temperature of 70 °C, and the reaction is maintained at this temperature for 60 minutes; sulfuric acid is added to adjust the pH to 7.0, then gradually cooled to 50 °C, and continue to distill under reduced pressure at low temperature for 3 hours to remove water; 10 parts by mass of ethyl acetate is added to prepare a mixed solution with a mass percentage concentration of 30%, cooled to 5 °C and centrifuged to remove sodium sulfate, and finally a phenolic resin solution is prepared.

[0040] Non-ionic surfactant solution: Prepare an aqueous solution with pH = 2, take 4-8 parts by mass of triblock polyether and dissolve it in 10 parts by mass of ethyl acetate, and then mix it with the aqueous solution with pH = 2 to form micelles. Control the temperature of the reaction kettle at 40 °C and stir for 1 hour to obtain it.

[0041] Mix the phenolic resin solution and the non-ionic surfactant solution, and then add a silicon source, and continue to stir to obtain a mixed solution containing phenolic resin, silicon source and non-ionic surfactant.

[0042] Mix the phenolic resin solution and the non-ionic surfactant solution, stir well and then add 3-5 parts by mass of silicon source (concentration 25%), and continue to stir and react in the kettle for 2 hours to obtain a mixed solution containing phenolic resin, silicon source and non-ionic surfactant.

[0043] The silicon source includes tetraethoxysilane (TEOS) and / or tetramethoxysilane (TMOS).

[0044] The non-ionic surfactant includes triblock polyether.

[0045] This triblock polyether needs to aggregate into micelles in an aqueous solution. The hydrophilicity of the EO block is stronger than that of the PO block. Therefore, this triblock polyether has a structure with a PO block as the core and an EO block as the shell layer. The molecular formula of the triblock polymer is: (EO)x-(PO)y-(EO)x.

[0046] The triblock polyether includes poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer P123 and / or PEO-PPO-PEO triblock copolymer F127.

[0047] The foaming material includes foam.

[0048] The foam is selected from one or more of PU (polyurethane) foam, EVA (ethylene-vinyl acetate copolymer) plastic, EPE (polyethylene) foam, SBR (styrene-butadiene rubber) foam, and EPDM (ethylene propylene diene monomer) foam.

[0049] The foam can also be a modified polyurethane material, including grafted or intercalated polyurethane composite materials. The grafted or intercalated functional groups include ester groups, amide groups, acrylate groups, disulfide bonds, thioether bonds, cyano groups, sulfate esters, etc. Polyurethane is generally a linear structure and is extremely sensitive to temperature, unable to withstand the climate changes in winter and summer, showing the phenomenon of "sticky when hot and brittle when cold"; moreover, the polyurethane emulsion has poor self-thickening property and low solid content.

[0050] The molecular structure of polyurethane is mainly composed of three functional groups, namely amino groups, methylene groups and carboxyl groups. There are many positions in this complex structure formed by the cross-linking of polyamide chains where functional groups can be added. The cross-linking of these functional groups and polyamide chains is the core structure of polyurethane modification, which determines various physical and chemical properties of polyurethane, such as anti-aging performance, flexibility, tensile strength and thermal stability, etc. Due to its molecular structure limitations, polyurethane has disadvantages such as poor heat resistance, water resistance and solvent resistance.

[0051] Preferably, the modified polyurethane material can be an acrylate or methacrylate modified polyurethane composite material. Acrylate has excellent weather resistance, water resistance and solvent resistance. The main absorption peak of the acrylate resin synthesized by copolymerizing acrylate and methacrylate monomers is outside the solar spectrum range, so the prepared acrylate resin has excellent light resistance and outdoor aging performance; making the polyurethane composite material have excellent chemical resistance and high and low temperature resistance.

[0052] The acrylate or methacrylate modified polyurethane composite material is prepared from acrylate modified polyurethane and contains acrylate functional groups and urethane bonds in its molecules. It has excellent fullness, hardness, gloss, solvent resistance and weather resistance, does not change color at high temperature and does not become brittle at low temperature. Its network structure, compared with polyurethane foam, promotes the more compact combination of the three-dimensional cavity fibers of the mesoporous-microporous carbon material, greatly improving the physical properties. After high-temperature carbonization in a nitrogen atmosphere, the hollow polyhedron polymer has a highly cross-linked and dense and ordered mesoscopic-microscopic structure. In this confined space, electron transition and energy level coupling splitting can be caused, which highlights the cross-linking enhanced emission effect and nano-small size effect. This three-dimensional system is very stable, and at high temperature, the skeleton shrinks and polymerizes and cross-links, further enhancing the structural advantages. The pore density of the foaming material is 45 - 60 PPI, and the surface hardness is 40 - 65 N; for the requirements of the foaming material, it is necessary to not only make the product have abundant pores, but also ensure relatively high mechanical strength and flexibility of the support layer. For example, if the PPI is less than 45, the support layer skeleton of the finished product is too thick, which affects the porosity. On the contrary, if the PPI is greater than 60, the support layer skeleton is too thin and the mechanical strength is insufficient. Another example is that if the surface hardness is less than 40, the mechanical strength of the finished product support layer is insufficient, and if it is greater than 65, it is too hard and loses flexibility.

[0053] There may also be other parameters, for example: the density is 18 - 40 kg / m 3 , the tensile strength is 0.1 - 0.12 Mpa, the tear strength ≤ 4.0 N / cm, the compression set ≤ 7%, and the resilience rate ≤ 35%. It may be: the density is 30 kg / m 3 , the surface hardness is 60 N, the tensile strength is 0.12 Mpa, the tear strength ≤ 4.0 N / cm, the compression set ≤ 7%, and the resilience rate ≤ 35%.

[0054] The foamed material has a rich skeleton morphology, a thermoplastic linear structure, good mechanical and adiabatic properties, light weight, high mechanical strength, and strong adhesion; and has a three-dimensional connected porous network structure. Using it as a template to construct a substrate with a porous structure can well replicate the mesoporous - microporous morphology of the foamed material.

[0055] For example, to prepare a mesoporous - microporous silica substrate: when silica gel is filled on the foamed material, the silica gel not only coats the scaffold of the foamed material, but also forms cell membranes in the spaces between the coated foamed material scaffolds, thereby obtaining a hollow polyhedral mesoporous - microporous silica substrate that replicates the cell units of the foamed material.

[0056] When using the foamed material as a skeleton and fully coating it with phenolic resin to form a cellular polyhedron, the mechanical strength is very high after carbonization; especially during roasting, the phenolic resin still polymerizes and crosslinks at high temperature, and the mechanical strength also increases. Therefore, what is obtained is a structure that maintains the network skeleton of the foamed material.

[0057] In step (1), the drying temperature is 80 - 150 °C; the drying time ≥ 20 h.

[0058] Place the foamed material in a mixed solution containing phenolic resin, silicon source, and non-ionic surfactant and stir evenly to allow the solution to fully infiltrate into the pores.

[0059] The well-perfused foamed material is placed in a cyclone dryer. After the solvent is completely volatilized at room temperature, it is loaded into a dedicated drying equipment. The temperature is maintained at 80 - 100 °C for 24 hours, then the temperature is raised to 150 °C and drying continues for 24 hours to obtain the first matrix.

[0060] The heating rate from 80 - 100 °C to 130 - 170 °C is 2 - 5 °C / min.

[0061] The phosphate ester compound includes one or more of triethyl phosphate, diethyl phosphate, ethyl dibutyl phosphate, and diethyl butyl phosphate.

[0062] In step (2), the reaction temperature is 160 - 180 °C and the time is 5 - 10 h.

[0063] After being fully infiltrated with the phosphate ester compound, it is placed in a special hydrothermal autoclave, and the reaction is carried out at a temperature of 160 - 180 °C for 6 hours, and then cooled to room temperature to obtain the second matrix; this second matrix is a cubic-phase hollow polyhedron material.

[0064] This step utilizes the property of the phosphate ester compound to selectively eliminate the foaming material to obtain a polyhedron material with rich pores.

[0065] When the foaming material is modified polyurethane, only the polyurethane is selectively eliminated, and it has no influence on the grafted or intercalated groups. For example, when the foaming material is a polyurethane composite modified with acrylate or methacrylate, the acrylate or methacrylate is retained, and only the polyurethane is removed.

[0066] By this chemical removal method, the acrylate is retained, which can increase the wall thickness. At the same time, the acrylate material with ultra-high porosity makes its porous structure more abundant, and it can also make substances combine and entangle with each other, further increasing the diversity of pores and the strength of the overall structure.

[0067] The polyurethane decomposed by the phosphate ester can be separated and recycled, reducing the production cost during industrial production.

[0068] Before step (3), the second matrix is washed twice with ethyl acetate and then three times with pure water, and then placed in a drying oven and dried at a temperature below 100 °C.

[0069] In step (3), the calcination conditions are: temperature 500 - 600 °C, time 2 - 5 h.

[0070] This step carbonizes the phenolic resin to obtain the third matrix; this third matrix is a hollow carbon-silica polyhedron composite material.

[0071] During calcination, substances such as phenolic resin, surfactant, and unremoved acrylate and methacrylate can still be further polymerized and crosslinked at high temperature, making the combination more compact and the mechanical strength stronger. During this process, silica can be more evenly distributed as the crosslinking proceeds, that is, it fills the entire structure. Through the above crosslinking, silica can be encapsulated to form a multi-layer pore structure, that is, a three-dimensional network structure with uniform pores and increased structural strength.

[0072] Compared with the case of directly calcining without removing polyurethane, it can avoid the collapse of the crosslinked structure and the situation of too large pores caused by the carbonization disappearance of polyurethane, thus developing a material with smaller, uniform, and higher-strength pores.

[0073] The inert gas includes at least one of nitrogen, helium, neon, argon, krypton, and xenon.

[0074] Step (4) is to react the third matrix with a hydrofluoric acid-containing solution to remove silicon oxide.

[0075] The mass ratio of the addition amount of the hydrofluoric acid-containing solution to the silicon source is: (4 - 6):(3 - 5).

[0076] The hydrofluoric acid-containing solution includes at least one of hydrofluoric acid, ammonium fluoride, ammonium bifluoride, and fluorosulfonic acid.

[0077] The third matrix is immersed in a hydrofluoric acid-containing solution and stirred to react to obtain an ordered mesoporous-microporous carbon composite material.

[0078] The reaction time is 8 - 12 h.

[0079] React at a speed of 50 - 120 rpm in a shaker for 8 - 12 h.

[0080] Then filter and wash, and finally dry at a temperature below 100 °C.

[0081] Example 2

[0082] This example provides an ordered mesoporous-microporous carbon composite material. The preparation method of this ordered mesoporous-microporous carbon composite material is the same as that described in Example 1 and will not be elaborated here.

[0083] The pore diameter of this ordered mesoporous-microporous carbon composite material is 0.2 - 2.5 nm; the specific surface area is 1100 - 1500 m 2 / g; the porosity is 75 - 85%.

[0084] Example 3

[0085] According to the content of this application, the preparation method of Example 1 and the ordered mesoporous-microporous carbon composite material of Example 2 are specifically described as follows:

[0086] Test Example 1

[0087] (1) At a temperature of 45 °C, dissolve 12 parts by mass of phenol with a concentration of 99% in an alkaline aqueous solution (1 part by mass of an aqueous solution with a pH of 12), and stir for 20 minutes; then add 20 parts by mass of an aqueous formaldehyde solution (with a concentration of 35%), gradually heat to a temperature of 70 °C, maintain this temperature, and react for 60 minutes; add sulfuric acid to adjust the pH to 7.0, then gradually cool down to 50 °C, and continue to distill under reduced pressure at a low temperature for 3 hours to remove water; add 10 parts by mass of ethyl acetate to prepare a mixed solution with a mass percentage concentration of 30%, cool to 5 °C and centrifuge to remove sodium sulfate, and finally prepare a phenolic resin solution.

[0088] Take 4 parts by mass of triblock polyether (P123) and dissolve it in 10 parts by mass of ethyl acetate, then mix it with 1 part by mass of an aqueous solution (pH = 2) to form micelles. Control the temperature at 40 °C and stir for 1 hour to obtain a nonionic surfactant solution.

[0089] Mix the phenolic resin solution and the nonionic surfactant solution, stir well, and then add 3 parts by mass of tetraethoxysilane (concentration 25%), and continue stirring and reacting for 2 hours to obtain a mixture containing phenolic resin, silicon source and nonionic surfactant.

[0090] Place 3 parts by mass of foamed polyurethane (pore density 45 PPI, surface hardness 40 N) in the mixture containing phenolic resin, silicon source and nonionic surfactant and stir evenly to allow the solution to fully infiltrate into the pores; then dry at 25 °C for 10 hours to completely volatilize the solvent; then dry at a temperature of 80 °C for 24 hours, and then raise the temperature to 150 °C and continue drying for 24 hours, with a heating rate of 2 °C / min to obtain the first matrix.

[0091] (2) After fully infiltrating the first matrix with 8 parts by mass of triethyl phosphate, maintain the temperature at 170 °C and react for 6 hours, then cool to room temperature; then wash with ethyl acetate, wash with water, and dry at 90 °C to obtain the second matrix.

[0092] (3) In a nitrogen atmosphere, calcine the second matrix at 550 °C for 3 hours to obtain the third matrix.

[0093] (4) Immerse the third matrix in 5 parts by mass of a hydrofluoric acid aqueous solution (concentration 20%), react at a speed of 60 rpm with a special shaker for 12 hours, then filter, wash with water, and dry at 100 °C to finally obtain an ordered mesoporous-microporous carbon composite material.

[0094] The morphologies of the foamed polyurethane, the first matrix, the second matrix, the third matrix, and the ordered mesoporous-microporous carbon composite material in this process are as Figure 1As shown in the figure, ① the SEM image of the foamed polyurethane shows a three-dimensional structure, and its connected network is composed of fine branched cell membranes, forming hollow irregular polyhedral cell units. The cavity size of the three-dimensional cell units is about 200 μm; ② the SEM image of the first matrix shows that the three-dimensional connected system composite material prepared based on the foamed polyurethane skeleton reaches the design goal, indicating that phenolic resin, triblock polyether F127, and tetraethoxysilane can achieve molecular self-assembly on the skeleton and further form new cell units; ③ the SEM image of the second matrix shows good chemical reaction characteristics with triethyl phosphate. The obtained polyhedral structure with rich pores after drying has a size of about 200 μm. The morphology presented by these three-dimensional ultramicrostructures (hollow polyhedra of cubic phase) coincides with the cell units of the foamed polyurethane; ④ the SEM image of the third matrix shows that the morphology of the hollow polyhedra is still intact after high-temperature carbonization at 550 °C, indicating that this three-dimensional system is very stable. And at high temperature, the skeleton shrinks, polymerizes and crosslinks, and the mechanical strength is also enhanced. Its cavity size is 100 μm; ⑤ the SEM image of the ordered mesoporous-microporous carbon product shows that after removing silica with hydrofluoric acid, the morphological characteristics of the obtained product are very completely retained, indicating that this preparation method can fully realize the affinity and interpenetration of carbon and silicon, and the three-dimensional system is well maintained after the removal of the silicon source.

[0095] FT-IR tests were carried out on the substances at each stage, and the results are as Figure 2 shown. Among them, in the spectrogram: a, the absorption peaks of O-H and C-C of phenolic resin are at 3500 - 1500 cm -1 , and the absorption peak of Si-OH of tetraethoxysilane is at ~1000 cm -1 ; b is the infrared spectrogram of the second matrix, showing that the absorption peak attributed to the foamed polyurethane disappears at ~1542 cm -1 , realizing that triethyl phosphate can selectively decompose with the foamed polyurethane, and it does not decompose the triblock polymer F127, tetraethoxysilane, and phenolic resin; c, the C-H and C-O absorption peaks of triblock polyether F127 are at 2800 - 1000 cm -1 ; d, the absorption peak of the foamed polyurethane is at ~1542 cm -1 .

[0096] Thermogravimetric analysis was carried out on the above substances, aiming to illustrate that ① phosphate can selectively remove the foamed polyurethane; ② the crosslinking and polymerization degree of the phenolic resin component increases greatly when reacting at 160 - 180 °C for 6 hours, and the carbon yield is high during high-temperature carbonization; ③ the surfactant, phenolic resin, and silicon source can combine with each other, and the weight loss temperatures of each component are different, taking each other into account, and the weight loss rate is greatly reduced. As Figure 3As shown, the thermogravimetric curve of a in Figure A shows a peak of rapid weight loss from 360 to 400 °C, and the differential thermogravimetric curve (phenolic resin) of a in Figure B shows a peak of rapid weight loss from 320 to 400 °C, with insignificant weight loss in the range of 420 to 900 °C;

[0097] The curve of b in Figure A is the second matrix, which is the thermogravimetric analysis after removing foamed polyurethane with triethyl phosphate. A peak of rapid weight loss appears at 380 to 410 °C, and the weight loss is relatively slow in the range of 410 to 900 °C. The differential thermogravimetric curve of b in Figure B shows a rapid peak at ~380 °C;

[0098] The thermogravimetric curve of c in Figure A is that of the triblock polymer F127, showing a peak of rapid weight loss at 380 to 400 °C, and the weight loss ratio reaches 98%. There is almost no weight loss in the range of 400 to 900 °C. c in Figure B shows a peak of rapid weight loss at 330 to 400 °C;

[0099] The thermogravimetric curve of d in Figure A is that of foamed polyurethane, showing weight loss starting at 240 to 300 °C, with a weight loss ratio of about 40%. There is rapid weight loss in the range of 300 to 400 °C, with a weight loss ratio of about 50%. There is almost no weight loss in the range of 400 to 900 °C. The differential thermogravimetric curve of d in Figure B shows that the weight loss peaks of foamed polyurethane appear in the ranges of ~240 °C and ~370 °C.

[0100] Test Example 2

[0101] (1) At a temperature of 45 °C, 14 parts by mass of phenol with a concentration of 99% is dissolved in an alkaline aqueous solution (1 part by mass of an aqueous solution with pH = 12), and stirred for 20 minutes; then 23 parts by mass of formaldehyde aqueous solution (concentration 35%) is added, and the temperature is gradually heated to 75 °C and maintained at this temperature for 60 minutes; sulfuric acid is added to adjust the pH to 7.5, and then the temperature is gradually lowered to 50 °C, and the mixture is continuously distilled under reduced pressure at low temperature for 3 hours to remove water; 12 parts by mass of ethyl acetate is added to prepare a mixed solution with a mass percentage concentration of 30%, cooled to 10 °C and centrifuged to remove sodium sulfate, and finally a phenolic resin solution is prepared.

[0102] Take 6 parts by mass of triblock polyether (F127) and dissolve it in 14 parts by mass of ethyl acetate, and then mix it with 1 part by mass of aqueous solution (pH = 2) to form micelles. Control the temperature at 45 °C and stir for 1 hour to obtain a nonionic surfactant solution.

[0103] Mix the phenolic resin solution and the nonionic surfactant solution, stir well, and then add 4 parts by mass of tetraethoxysilane (concentration 25%), and continue to stir and react for 3 hours to obtain a mixed solution containing phenolic resin, silicon source and nonionic surfactant.

[0104] Place 4 parts by mass of modified polyurethane (acrylate polyurethane, model: W905, source: Wanhua Chemical) (with a pore density of 60 PPI and a surface hardness of 60 N) in a mixed solution containing phenolic resin, silicon source and non-ionic surfactant and stir evenly to allow the solution to fully infiltrate into the pores; then dry at 30 °C for 8 hours to completely volatilize the solvent; then dry at a temperature of 90 °C for 24 hours, then raise the temperature to 150 °C and continue to dry for 24 hours, with a heating rate of 3 °C / min to obtain the first matrix.

[0105] (2) After fully infiltrating the first matrix with 9 parts by mass of triethyl phosphate, react at a temperature of 180 °C for 6 hours, and then cool to room temperature; then wash with ethyl acetate, wash with water, and dry at 95 °C to obtain the second matrix.

[0106] (3) In a nitrogen atmosphere, calcine the second matrix at 600 °C for 3 hours to obtain the third matrix.

[0107] (4) Immerse the third matrix in 6 parts by mass of hydrofluoric acid aqueous solution (concentration: 18%), react on a special shaker at a speed of 80 rpm for 12 hours, then filter, wash with clear water, and dry at 90 °C to finally obtain an ordered mesoporous-microporous carbon composite material. The morphology is as Figure 4 shown. The obtained product is a three-dimensional ultrafine particle with abundant pores and containing ordered mesopores-micropores, with a novel structure and excellent mechanical stability and chemical stability.

[0108] Test Example 3

[0109] (1) At a temperature of 50 °C, dissolve 15 parts by mass of phenol with a concentration of 99% in an alkaline aqueous solution (1 part by mass of an aqueous solution with a pH of 12), stir for 20 minutes; then add 25 parts by mass of formaldehyde aqueous solution (concentration 40%), gradually heat to a temperature of 75 °C, maintain this temperature, and react for 70 minutes; add sulfuric acid to adjust the pH to 7.5, then gradually cool to 50 °C, and continue to distill under reduced pressure and low temperature for 3 hours to remove water; add 13 parts by mass of ethyl acetate to prepare a mixed solution with a mass percentage concentration of 30%, cool to 10 °C and centrifuge to remove sodium sulfate, and finally prepare a phenolic resin solution.

[0110] Take 8 parts by mass of triblock polyether (mass ratio of P123 to F127 is 1:1) and dissolve it in 15 parts by mass of ethyl acetate, and then mix it with 1 part by mass of aqueous solution (pH = 2) to form micelles, control the temperature at 45 °C, and stir for 1.5 hours to obtain a non-ionic surfactant solution.

[0111] Mix the phenolic resin solution and the non-ionic surfactant solution. After stirring well, add 5 parts by mass of tetraethoxysilane (concentration 25%) and continue stirring and reacting for 3 hours to obtain a mixed solution containing phenolic resin, silicon source, and non-ionic surfactant.

[0112] Place 4 parts by mass of modified polyurethane (acrylate polyurethane, model: W901, source: Wanhua Chemical) (pore density 55 PPI, surface hardness 60 N) into the mixed solution containing phenolic resin, silicon source, and non-ionic surfactant and stir evenly to allow the solution to fully infiltrate into the pores; then dry at 30 °C for 8 hours to completely volatilize the solvent; then dry at a temperature of 100 °C for 24 hours, then raise the temperature to 150 °C and continue drying for 24 hours, with a heating rate of 4 °C / min to obtain the first matrix.

[0113] (2) After fully infiltrating the first matrix with 10 parts by mass of triethyl phosphate, maintain the temperature at 180 °C and react for 6 hours, then cool to room temperature; then wash with ethyl acetate, wash with water, and dry at 100 °C to obtain the second matrix.

[0114] (3) In a nitrogen atmosphere, calcine the second matrix at 600 °C for 3 hours to obtain the third matrix.

[0115] (4) Immerse the third matrix in 6 parts by mass of hydrofluoric acid aqueous solution (concentration 16%), react at a speed of 100 rpm with a special shaker for 12 hours, then filter, wash with clear water, and dry at 100 °C to finally obtain an ordered mesoporous-microporous carbon composite material. The morphology is as Figure 5 shown. The obtained product is a three-dimensional ultrafine particle with rich pores and containing ordered mesopores-micropores, with a novel structure and excellent mechanical stability and chemical stability.

[0116] Comparative Example 1

[0117] It is basically the same as the test example, except that the foamed polyurethane in step (1) and step (2) are missing. That is, the specific steps of this comparative example are as follows:

[0118] (1) At a temperature of 45 °C, dissolve 12 parts by mass of phenol with a concentration of 99% in an alkaline aqueous solution (1 part by mass of an aqueous solution with pH = 12), stir for 20 minutes; then add 20 parts by mass of formaldehyde aqueous solution (concentration 35%), gradually heat to a temperature of 70 °C, maintain this temperature, and react for 60 minutes; add sulfuric acid to adjust the pH to 7.0, then gradually cool to 50 °C, and continue to distill under reduced pressure at low temperature for 3 hours to remove water; add 10 parts by mass of ethyl acetate to prepare a mixed solution with a mass percentage concentration of 30%, cool to 5 °C and centrifuge to remove sodium sulfate, and finally prepare a phenolic resin solution.

[0119] Take 4 parts by mass of triblock polyether (P123) and dissolve it in 10 parts by mass of ethyl acetate, then mix it with 1 part by mass of aqueous solution (pH = 2) to form micelles. Control the temperature at 40 °C and stir for 1 hour to obtain a non-ionic surfactant solution.

[0120] Mix the phenolic resin solution and the non-ionic surfactant solution, and mechanically stir under the condition of 40 °C for 3 hours to obtain a viscous yellow transparent mixture; then add 3 parts by mass of tetraethoxysilane (concentration 25%), and continue to stir and react for 2 hours to obtain a mixed solution containing phenolic resin, silicon source and non-ionic surfactant.

[0121] After the mixture is centrifuged, it is dried at 100 °C for 20 hours. When the moisture content of the obtained dry product is 25%, it is then ground into powder.

[0122] (2) In a nitrogen atmosphere, calcine the above powder at 550 °C for 3 hours to obtain the third parent body.

[0123] (3) Immerse the third parent body in 5 parts by mass of hydrofluoric acid aqueous solution (concentration 20%), react at a speed of 60 rpm with a special shaker for 12 hours, then filter, wash with clear water, and dry at 100 °C to finally obtain the mesoporous-microporous carbon composite material.

[0124] In the ordered mesoporous-microporous carbon composite material obtained by this method, its mesoporous silica substrate is amorphous, with poor mechanical strength and easy to crack. And it is compared with the ordered mesoporous-microporous carbon composite material obtained in Test Example 1, and the specific results are shown in Table 1.

[0125] Table 1

[0126]

[0127] Comparative Example 2

[0128] Low-temperature aqueous phase synthesis method:

[0129] Take 6.50 g of triblock polymer F127 as the surfactant, 1.0 g of 0.2 mol / L HCl solution, dissolve it in 10.0 g of absolute ethanol, stir at 40 °C for 1 h to obtain a clear solution, then gradually add 8.0 g of tetraethyl orthosilicate as the silicon source and 20.0 g of phenolic ethanol solution with a concentration of 20%, and magnetically stir for 2 hours to obtain a transparent homogeneous solution. Then transfer it to an evaporating dish, induce self-assembly by volatilization at room temperature for 6 h, and then place it in an oven at 100 °C for thermal polymerization for 24 hours.

[0130] The dried sample was subjected to programmed temperature carbonization in a tubular furnace with high-purity nitrogen flowing through. It was maintained at 350 °C for 3 h and at 900 °C for 2 h. The heating rate was controlled as follows: 1 °C / min below 600 °C and 5 °C / min above 600 °C. The sample was taken out and ground into powder to obtain the mesoporous C-SiO2 composite material.

[0131] Then, it was impregnated with a 10% HF solution at room temperature for 24 h to remove silicon oxide, and then rinsed with a large amount of deionized water. Finally, the material was dried in an oven at 100 °C to obtain the ordered mesoporous carbon material.

[0132] This method system has a low concentration and cannot regulate the morphology of mesoporous carbon; it is difficult to carry out large-scale synthesis; there is a lack of in-depth research on many aspects such as the control of influencing factors in the process of crystal nucleus formation and crystal growth, and no satisfactory conclusion has been obtained; it has a strong dependence on production equipment, which also affects and hinders the development of this method. This method has a complex process, is time-consuming and uneconomical, and the stability of the mesoporous carbon material synthesized by the reverse phase is relatively poor.

[0133] The comparison results with the preparation method of this application are shown in Table 2.

[0134] Table 2

[0135]

[0136] Comparative Example 3

[0137] 3 g of ZnO nanoparticles were placed in 25 cm 3 of distilled water. After slightly stirring, 10 g of 10% polyacrylamide was added. The mixed solution was stirred at a speed of 700 rpm for 4 hours and then dispersed by ultrasonic for 1 hour. After drying at 100 °C for 4 hours, the ZnO / polyacrylamide nanocomposite was obtained. The obtained ZnO / polyacrylamide nanocomposite was calcined at 700 °C for 3 hours in an atmosphere of 97% N2 + 3% H2 to obtain the C / ZnO nanocomposite. The C / ZnO nanocomposite was treated in 50 cm 3 of 10% acetic acid solution to dissolve the ZnO template, and then washed with distilled water to obtain the mesoporous carbon material.

[0138] For the mesoporous carbon prepared by this method, due to the inability to precisely control the position of ZnO, the structure, size and pore distribution of the mesopores in the mesoporous carbon material are also randomly distributed and cannot be arranged orderly; and due to the catalyst being a metal-containing salt, the problem of metal residue in the final product is also very serious.

[0139] Comparative Example 4

[0140] (1) At a temperature of 45 °C, 14 parts by mass of phenol with a concentration of 99% is dissolved in an alkaline aqueous solution (1 part by mass of an aqueous solution with a pH of 12), and stirred for 20 minutes; then 23 parts by mass of an aqueous formaldehyde solution (concentration 35%) is added, and the temperature is gradually raised to 75 °C and maintained at this temperature for 60 minutes; sulfuric acid is added to adjust the pH to 7.5, and then the temperature is gradually lowered to 50 °C, and low-temperature distillation under reduced pressure is continued for 3 hours to remove water; 12 parts by mass of ethyl acetate is added to prepare a mixed solution with a mass percentage concentration of 30%, cooled to 10 °C, and sodium sulfate is removed by centrifugation, and finally a phenolic resin solution is prepared.

[0141] Take 6 parts by mass of triblock polyether (F127) and dissolve it in 14 parts by mass of ethyl acetate, and then mix it with 1 part by mass of an aqueous solution (pH = 2) to form micelles. Control the temperature at 45 °C and stir for 1 hour to obtain a non-ionic surfactant solution.

[0142] Mix the phenolic resin solution and the non-ionic surfactant solution, stir well, then add 4 parts by mass of tetraethoxysilane (concentration 25%), and continue stirring and reacting for 3 hours to obtain a mixed solution containing phenolic resin, silicon source and non-ionic surfactant.

[0143] Put 4 parts by mass of foamed polyurethane (pore density of 50 PPI, density of 35 kg / m 3 , surface hardness of 50 N, tensile strength of 0.12 Mpa, tear strength ≤ 4.0 N / cm, compression set ≤ 7%, rebound rate ≤ 35%) into the mixed solution containing phenolic resin, silicon source and non-ionic surfactant and stir evenly to make the solution fully infiltrate into the pores; then dry at 30 °C for 8 hours to completely volatilize the solvent; then dry at a temperature of 90 °C for 24 hours, and then raise the temperature to 150 °C and continue drying for 24 hours, with a heating rate of 3 °C / min to obtain the first matrix.

[0144] (2) In a nitrogen atmosphere, the first matrix is calcined at 350 °C for 3 hours, and then calcined at 600 °C for 3 hours to obtain the third matrix.

[0145] (3) Immerse the third matrix in 6 parts by mass of an aqueous hydrofluoric acid solution (concentration 18%), react with a special shaker at a speed of 80 rpm for 12 hours, then filter, wash with water, and dry at 90 °C to finally obtain an ordered mesoporous-microporous carbon composite material with a pore diameter of 5 nm and a specific surface area of 610 m 2 / g.

[0146] Performance test

[0147] (1) The ordered mesoporous-microporous carbon composite material obtained in the test example is characterized by SEM scanning, FT-IR test, TGA thermogravimetric analysis, etc., and the results are shown in Table 3.

[0148] Table 3

[0149]

[0150] As shown in Table 3, polyurethane was used in Test Example 1, and the obtained ordered mesoporous-microporous carbon composite was slightly inferior to Test Example 2 and Test Example 3 in terms of various parameters; the modified polyurethane in Test Example 2 and Test Example 3 could, after removing the polyurethane, undergo condensation cross-linking with substances such as phenolic resin during the calcination stage, greatly enhancing the strength of the composite material, and could control the pore size to achieve a composite material with smaller and uniform pore sizes. In Comparative Example 1, no polyurethane was used, and it was merely obtained based on the self-assembly between phenolic resin, silicon, and surfactant. However, in this process, it was difficult to obtain an ordered structure, mostly in an amorphous state, with low mechanical strength, poor mechanical properties, large pore sizes, and limited scope of application. Comparative Example 4 adopted the polyurethane scheme, but compared with Comparative Example 2, it did not use modified polyurethane and did not remove the polyurethane in advance. It only underwent carbonization during the calcination stage, which would cause a reduction in pores, and the removal of the polyurethane skeleton would cause problems with poor stability of the overall structure, and the pore sizes were large, and smaller pores could not be obtained, and the pore size distribution was uneven.

[0151] (2) Research on the COD adsorption performance of the ordered mesoporous-microporous carbon composites obtained from the test examples and comparative examples. Currently in China, our team is the first to use mesoporous-microporous carbon materials to treat the COD in high-salt coal chemical wastewater because our team has mastered the technology for industrial synthesis of mesoporous carbon materials, which is unique. The commonly used technology in the industry before was the method of "ozone + activated carbon".

[0152] The treatment of organic matter, namely COD, in high-salt coal chemical wastewater usually adopts processes such as biochemical systems, ozone systems, and activated carbon adsorption. However, there is still some COD that cannot be removed, resulting in 10 - 15% of miscellaneous salts being generated in the subsequent salt separation and crystallization section. According to relevant laws and regulations, this miscellaneous salt is disposed of as hazardous waste, and the disposal cost is 3000 - 5000 yuan / ton, bringing a relatively large economic burden to the enterprise.

[0153] The main COD (organic characteristic pollutants) in high-salt coal chemical wastewater are nearly 40 kinds such as humin, fulvic acid, dimethylpyridine, acetophenone, glutaraldehyde, citric anhydride, chloromethyl thiocyanate, and ethylacetamide; this organic matter has the characteristics of complex components, small relative molecular mass, high biological toxicity, and great degradation difficulty, and environmental protection treatment is very difficult.

[0154] In addition, since the molecular weights of the elements in COD are relatively small (<150 Da, as shown in Table 4 specifically), it is a disperse substance composed of particulate matter with a particle size less than 1 nm. If an ordered mesoporous carbon composite material with a relatively large pore size is used, good treatment effects cannot be achieved.

[0155] Table 4

[0156]

[0157] Ordered mesoporous carbon materials have the characteristics of high specific surface area, high porosity, and corrosion resistance. Moreover, the composition and pore size of this material can be flexibly adjusted. Therefore, when adsorbing and separating substances with different molecular structures and molecular weights, they have great advantages in terms of selectivity and desorption. These characteristics of ordered mesoporous carbon materials show great application prospects in the adsorption and separation, efficient treatment, recycling, and cost saving of organic matter in high-salt wastewater from coal chemical industry.

[0158] The ordered mesoporous-microporous carbon composites obtained from the test examples and comparative examples were respectively used to adsorb COD to detect their adsorption performance for COD in high-concentration wastewater from coal chemical industry.

[0159] The source of the wastewater is the concentrate of high-pressure reverse osmosis RO, and the COD of the water quality before treatment is 350 mg / l.

[0160] The specific test process is as follows: The ordered mesoporous-microporous carbon composites obtained from the test examples and comparative examples were respectively added to the high-concentration wastewater from coal chemical industry at a ratio of 10 g:100 mL. After oscillating for 5 h, the ordered mesoporous-microporous carbon composites were separated from the high-concentration wastewater from coal chemical industry. Then, the content of COD in the high-concentration wastewater from coal chemical industry after adsorption was detected, and the removal rate of COD was calculated. The formula is: (the content of COD before adsorption - the content of COD before adsorption) / the content of COD before adsorption. The test results are shown in Table 5.

[0161] Table 5

[0162]

[0163]

[0164] Figure 6For the front and back comparison photos of multiple removals of COD from high-salt coal chemical wastewater in Test Example 2, it can be seen that the water after filtration is colorless and transparent, showing a significant improvement compared to the yellow color of the wastewater. And as can be seen from Table 5, Test Example 2 and Test Example 3 of the modified polyurethane have the best effect in adsorbing COD. In Comparative Examples 1-4, different technical solutions from the present application are adopted. Due to reasons such as the relatively large pore size of the obtained mesoporous carbon materials, their adsorption performance for COD is limited and they cannot achieve a good adsorption effect. In addition, the ordered mesoporous-microporous carbon composite material of the present application has a good effect in adsorbing COD with a smaller size because it can obtain a structure with micropores. Generally speaking, the adsorption effects of Test Examples 1-3 of the present application are far higher than those of Comparative Examples 1-4, and they also have a relatively long service life, can achieve a good industrial utilization rate, and reduce costs. Compared with the method of "ozone + activated carbon", the removal rate of the present application is also greatly improved, and there is no miscellaneous salt generated in the subsequent salt separation and crystallization section, which can greatly reduce the economic burden on enterprises. And it can be produced in advance to avoid the disadvantage that ozone needs to be produced and used immediately.

[0165] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, or improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing an ordered mesoporous-microporous carbon composite material, characterized in that, Comprising: (1) Immerse the foaming material in a mixed solution containing phenolic resin, silicon source and non-ionic surfactant, and dry to obtain the first matrix; (2) Mix the first matrix with a phosphate compound and react to obtain the second matrix. The reaction temperature is 160-180°C and the time is 5-10 h; (3) Calcinate the second matrix under an inert gas to obtain the third matrix; (4) React the third matrix with a hydrofluoric acid-containing solution to generate an ordered mesoporous-microporous carbon composite material; The foaming material is polyurethane.

2. The preparation method according to claim 1, wherein The mass ratio of the foaming material, phenolic resin, silicon source and non-ionic surfactant is: (2-4) : (19.2-24) : (3-5) : (4-8).

3. The preparation method according to claim 1, characterized in that, Wherein, The pore density of the foaming material is 45-60 PPI and the surface hardness is 40-65 N.

4. The preparation method according to claim 1, wherein In step (1), first dry at 80-100°C for ≥20 h, and then dry at 130-170°C for ≥20 h; in step (3), the calcination conditions are: temperature 500-600°C and time 2-5 h.

5. The preparation method according to claim 1, characterized in that The mass ratio of the addition amount of the phosphate compound to the foaming material is: (8-10) : (2-4).

6. The preparation method according to claim 1, wherein The mass ratio of the addition amount of the hydrofluoric acid-containing solution to the silicon source is: (4-6) : (3-5).

7. An ordered mesoporous-microporous carbon composite material prepared by the preparation method according to any one of claims 1-6.

8. The ordered mesoporous-microporous carbon composite material according to claim 7, wherein The pore size of the ordered mesoporous-microporous carbon composite is 0.2 - 2.5 nm; the specific surface area is 1100 - 1500 m 2 / g; the porosity is 75 - 85%.

9. Application of the ordered mesoporous-microporous carbon composite material according to claim 7 or 8 in removing COD from coal chemical industrial concentrated brine.

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