Organic nanocage adsorption material and preparation method thereof

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to an organic nanocage adsorption material and a preparation method thereof. According to the invention, an organic nanocage structure is introduced on the activated carbon through Friedel-Crafts alkylation reaction, so that the adsorption capacity and selectivity of the activated carbon can be effectively increased. The prepared adsorbing material has good regeneration capacity, namely, the adsorbing material can be regenerated through a simple physical or chemical method after adsorption saturation, so that the use cost is reduced, and secondary pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to an organic nano cage adsorption material and a preparation method thereof. Background Art

[0002] Power plant boilers, also known as "power plant boilers", refer to medium and large boilers in power plants that provide a specified amount and quality of steam to steam turbines. One of the main thermal equipment in thermal power plants. The water quality must meet the relevant requirements of " HYPERLINK "javascript:void(0)" GB / T 12145-2016 Water quality for thermal power generating units and steam power equipment"; such as iron and copper ion concentrations, TOC (total organic carbon), conductivity, etc. Therefore, under normal circumstances, tap water, river water, and sewage treated water that meets discharge standards cannot meet the requirements and must be treated before use.

[0003] At present, general power plants use tap water or fresh water as raw water for boiler water preparation, and most of them use fiber filters, ion exchange systems and activated carbon filters alone or in combination to prepare relevant water.

[0004] As a mechanical filter, the fiber filter makes the porosity of the filter material gradually decrease along the water flow direction through the extrusion between the movable orifice plate and the filter layer, and the fiber density increases. In the filtering state, there are both longitudinal deep filtration and transverse deep filtration, which effectively improves the filtration accuracy and filtration speed.

[0005] In the ion exchange system, the strong alkaline anion exchange resin is often contaminated by impurities such as grease and organic matter during operation, which reduces the exchange capacity.

[0006] The activated carbon filter uses adsorption to remove organic matter from the water. It can also remove residual chlorine, grease, colloidal silica and suspended matter in the water, thereby delaying the contamination of the anionic resin and extending the life of the resin.

[0007] The boiler feed water is obtained by treating the raw water with a desalination water production process combining mechanical filtration with a cation bed + anion bed + mixed bed. However, the ion exchange resin in this process is easily saturated and often requires frequent cleaning and regeneration. In addition, a large amount of strong acid and alkali is required during regeneration, so the anti-corrosion requirements of the equipment are high.

[0008] However, with the increasing awareness of environmental protection and energy conservation and emission reduction, there is a great demand for the recycling of used wastewater. Summary of the invention

[0009] Oligomeric silsesquioxanes have good prospects for preparing hybrid nanoscale porous materials due to their supporting nanoscale cage structure, easy modification, and excellent stability. Octavinyl silsesquioxane (OVS), as the simplest representative compound, is of great significance to the development of oligomeric silsesquioxanes; however, at present, more research is focused on the development of the material itself, and there is still little development of oligomeric silsesquioxanes attached to other materials as coatings or composite materials. The present invention mainly uses oligomeric silsesquioxane attached to activated carbon as the main research direction, and provides an organic nanocage adsorption material and a preparation method thereof, which has better adsorption effect; and the adsorption performance attenuation is small.

[0010] A method for preparing an organic nanocage adsorption material comprises the following steps: (1) Add activated carbon into the solvent and set aside; (2) Octavinylsilsesquioxane is used as a polymerization monomer and reacts with an aromatic compound in a solvent under the action of a catalyst to undergo a Friedel-Crafts alkylation reaction and attach to activated carbon; after the reaction, an organic nanocage adsorption material is obtained.

[0011] Preferably, the specific surface area of ​​the activated carbon is ≥850 m² / g; the porosity is ≥98%; and the iodine value is ≥800.

[0012] Preferably, the catalyst is anhydrous aluminum chloride.

[0013] Preferably, the solvent is one of dichloromethane and dichloroethane.

[0014] Preferably, the aromatic compound is a non-condensed aromatic hydrocarbon with ≤4 carbon atoms outside the benzene ring, and more preferably at least one of the following: Benzene, toluene, xylene, ethylbenzene, butylbenzene, biphenyl.

[0015] Preferably, the molar ratio of the octavinylsilsesquioxane to the aromatic compound is 1:2-6.

[0016] Preferably, the ratio of octavinylsilsesquioxane to activated carbon is 0.2-0.4:1.

[0017] Preferably, the reaction temperature of step (2) is ≤80°C and the reaction time is ≤24h.

[0018] An organic nano cage adsorption material is prepared by the above-mentioned preparation method.

[0019] The invention uses octavinyl silsesquioxane as a polymerization monomer and carries out Friedel-Crafts alkylation reaction with an aromatic compound in a solvent under the action of a catalyst to obtain an oligomeric porous oligomeric silsesquioxane product, which is then attached to activated carbon to obtain an organic nano cage adsorption material.

[0020] The present invention selects activated carbon with high specific surface area and high porosity as the base material, which can provide a large number of adsorption sites and enhance the adsorption capacity of the adsorption material. The high iodine value indicates that the activated carbon has good adsorption performance, which is crucial for the preparation of efficient adsorption materials.

[0021] The introduction of organic nanocage structures on activated carbon through Friedel-Crafts alkylation reaction can effectively increase the adsorption capacity and selectivity of activated carbon. This reaction usually generates organic molecules with specific functional groups, thereby improving the material's adsorption capacity for specific substances.

[0022] Anhydrous aluminum chloride is used as a catalyst, which is a strong Lewis acid and can effectively promote the alkylation reaction while having relatively low requirements on the environment and equipment.

[0023] In addition to octavinyl silsesquioxane, the present invention selects non-condensed aromatic hydrocarbons with carbon numbers outside the benzene ring of ≤4 as reactants. These compounds have good reaction activity and selectivity and are conducive to forming a well-structured organic nano cage.

[0024] The invention specifies the ratio of octavinyl silsesquioxane, aromatic compound and activated carbon, which is helpful to form a uniform and dense organic nano cage structure, thereby improving the performance of the adsorption material.

[0025] Compared with the prior art, the present invention can effectively adsorb organic pollutants and heavy metal ions in water because it uses activated carbon with high specific surface area and high porosity as a substrate.

[0026] At the same time, the adsorption material prepared by the present invention has good regeneration ability, that is, it can be regenerated by simple physical or chemical methods after adsorption saturation, thereby reducing the use cost and reducing secondary pollution. DETAILED DESCRIPTION

[0027] In order to better understand the present invention, the present invention is further described below in conjunction with specific serial numbers, wherein the terms used in the serial numbers are for describing specific embodiments and do not constitute limitations on the scope of protection of the present invention.

[0028] Specific implementation methods, unless otherwise specified, are conventional experimental methods, and the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0029] The sources of some raw materials used in the present invention are as follows: Table 1: Table 1 Example 1 Preparation of organic nanocage adsorption material (1) Add 3.2 g of activated carbon A to 50 ml of dichloromethane as solvent and set aside; (2) Add 0.63 g (1 mmol) of octavinylsilsesquioxane, 0.47 g (6 mmol) of benzene, and 0.19 g (1.43 mmol) of anhydrous aluminum chloride to the solvent; stir at room temperature for 20 min; then raise the temperature to 80 °C and keep stirring for 24 h.

[0030] (3) After completion, the reaction mixture was cooled to room temperature, the solid product was filtered out, and washed with tetrahydrofuran, dichloromethane, dichloroethane, and acetone in sequence; and then dried under vacuum at 70°C for 48 hours to obtain an organic nanocage adsorption material.

[0031] Example 2 Preparation of organic nanocage adsorption material (1) Add 3.2 g of activated carbon A to 50 ml of dichlorohexane as solvent and set aside; (2) Add 0.63 g (1 mmol) of octavinylsilsesquioxane, 0.55 g (6 mmol) of toluene, and 0.19 g (1.43 mmol) of anhydrous aluminum chloride to the solvent; stir at room temperature for 20 min; then raise the temperature to 80 °C and keep stirring for 24 h.

[0032] (3) After completion, the reaction mixture was cooled to room temperature, the solid product was filtered out, and washed with tetrahydrofuran, dichloromethane, dichloroethane, and acetone in sequence; and then dried under vacuum at 70°C for 48 hours to obtain an organic nanocage adsorption material.

[0033] Example 3 Preparation of organic nanocage adsorption material (1) Add 1.58 g of activated carbon A to 50 ml of dichloromethane as solvent and set aside; (2) Add 0.63 g (1 mmol) of octavinylsilsesquioxane, 0.21 g (2 mmol) of xylene, and 0.19 g (1.43 mmol) of anhydrous aluminum chloride to the solvent; stir at room temperature for 20 min; then raise the temperature to 80 °C and keep stirring for 24 h.

[0034] (3) After completion, the reaction mixture was cooled to room temperature, the solid product was filtered out, and washed with tetrahydrofuran, dichloromethane, dichloroethane, and acetone in sequence; and then dried under vacuum at 70°C for 48 hours to obtain an organic nanocage adsorption material.

[0035] Example 4 Preparation of organic nanocage adsorption material (1) Add 3.2 g of activated carbon A to 50 ml of dichloromethane as solvent and set aside; (2) Add 0.63 g (1 mmol) of octavinylsilsesquioxane, 0.32 g (3 mmol) of ethylbenzene, and 0.19 g (1.43 mmol) of anhydrous aluminum chloride to the solvent; stir at room temperature for 20 min; then raise the temperature to 80 °C and keep stirring for 24 h.

[0036] (3) After completion, the reaction mixture was cooled to room temperature, the solid product was filtered out, and washed with tetrahydrofuran, dichloromethane, dichloroethane, and acetone in sequence; and then dried under vacuum at 70°C for 48 hours to obtain an organic nanocage adsorption material.

[0037] Example 5 Preparation of organic nanocage adsorption material (1) Add 3.2 g of activated carbon A to 50 ml of dichloromethane as solvent and set aside; (2) Add 0.63 g (1 mmol) of octavinylsilsesquioxane, 0.54 g (4 mmol) of butylbenzene, and 0.19 g (1.43 mmol) of anhydrous aluminum chloride to the solvent; stir at room temperature for 20 min; then heat to 80 °C and keep stirring for 24 h.

[0038] (3) After completion, the reaction mixture was cooled to room temperature, the solid product was filtered out, and washed with tetrahydrofuran, dichloromethane, dichloroethane, and acetone in sequence; and then dried under vacuum at 70°C for 48 hours to obtain an organic nanocage adsorption material.

[0039] Example 6 Preparation of organic nanocage adsorption material (1) Add 3.2 g of activated carbon A to 50 ml of dichloromethane as solvent and set aside; (2) Add 0.63 g (1 mmol) of octavinylsilsesquioxane, 0.46 g (3 mmol) of biphenyl, and 0.19 g (1.43 mmol) of anhydrous aluminum chloride to the solvent; stir at room temperature for 20 min; then heat to 80 °C and keep stirring for 24 h.

[0040] (3) After completion, the reaction mixture was cooled to room temperature, the solid product was filtered out, and washed with tetrahydrofuran, dichloromethane, dichloroethane, and acetone in sequence; and then dried under vacuum at 70°C for 48 hours to obtain an organic nanocage adsorption material.

[0041] Comparative Example 1 Preparation of organic nanocage adsorption material The difference from Example 1 is that activated carbon B is used instead of activated carbon A in step (1).

[0042] Comparative Example 2 Preparation of organic nanocage adsorption materials The difference from Example 1 is that the reaction temperature in step (2) is 60°C.

[0043] Comparative Example 3 Preparation of organic nanocage adsorption material The difference from Example 1 is that in step (2), 0.828 g (6 mmol) of salicylic acid is used instead of 0.47 g (6 mmol) of benzene.

[0044] Adsorption capacity test Test method: The adsorption materials prepared in each embodiment and each comparative example were added into the simulated sewage at an addition amount of 30 g / L. After stirring and adsorbing at 60 rpm for 90 min, the corresponding pollutant content in the simulated sewage was detected and the removal rate was calculated.

[0045] The simulated sewage contains: Nickel chloride content is 10mg / L Zinc chloride content is 50mg / L Copper sulfate content is 60mg / L The content of iron nitrate is 60ml / L At the same time, hydrochloric acid was used to adjust the pH to 5.

[0046] The results are shown in Table 2.

[0047] Table 2 Adsorption results From Table 2, the comparison between Example 1 and Comparative Example 1 shows that when activated carbon with different performance indicators is used as the attachment substrate, significant differences in performance will occur.

[0048] Comparison between Example 1 and Comparative Example 2 shows that a lower reaction temperature leads to a decrease in adsorption performance, which the present invention speculates is due to an incomplete reaction.

[0049] By comparing Example 1 with Comparative Example 3, the present invention speculates that due to the presence of two strong electron-withdrawing groups, hydroxyl (-OH) and carboxyl (-COOH), in the structure of salicylic acid, they will significantly reduce the electron density of the benzene ring, thereby reducing its reactivity; ultimately resulting in a large number of gaps originally possessed by the activated carbon being blocked, which in turn reduces the adsorption capacity. The present invention speculates that other aromatic compounds containing hydroxyl and carboxyl groups will also fail to react correctly for the same reason.

[0050] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A method for preparing an organic nanocage adsorption material, characterized in that: The following steps are involved: (1) Add activated carbon into the solvent and set aside; (2) Octavinylsilsesquioxane is used as a polymerization monomer and reacts with an aromatic compound in a solvent under the action of a catalyst to undergo a Friedel-Crafts alkylation reaction and attach to activated carbon; after the reaction, an organic nanocage adsorption material is obtained.

2. The preparation method according to claim 1, characterized in that: The specific surface area of ​​the activated carbon is ≥850m² / g; the porosity is ≥98%; and the iodine value is ≥800.

3. The preparation method according to claim 1, characterized in that: The catalyst is anhydrous aluminum chloride.

4. The preparation method according to claim 1, characterized in that: The solvent is one of dichloromethane and dichloroethane.

5. The preparation method according to claim 1, characterized in that: The aromatic compound is a non-condensed ring aromatic hydrocarbon with 4 or less carbon atoms outside the benzene ring.

6. The preparation method according to claim 5, characterized in that: The aromatic compound is at least one of the following: Benzene, toluene, xylene, ethylbenzene, butylbenzene, biphenyl.

7. The preparation method according to claim 1, characterized in that: The molar ratio of the octavinylsilsesquioxane to the aromatic compound is 1:2-6.

8. The preparation method according to claim 1, characterized in that: The ratio of the octavinyl silsesquioxane to the activated carbon is 0.2-0.4:

1.

9. The preparation method according to claim 1, characterized in that: The reaction temperature of step (2) is ≤80°C and the reaction time is ≤24h.

10. An organic nanocage adsorption material, characterized in that Prepared by the preparation method according to any one of claims 1 to 9.

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