Synthesis method of carboxyl functionalized mesoporous material
By synthesizing carboxyl functionalized mesoporous materials and modifying SBA-15 with malonic acid, the existing adsorbents have poor selective adsorption properties and low adsorption amounts of heavy metal ions in the removal wastewater, and the efficient adsorption effect of a variety of heavy metal ions is achieved.
Patent Information
- Application Number
- CN202411980256.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-05-13
AI Technical Summary
In the process of removing heavy metal ions in wastewater, existing adsorbents have problems such as poor selection adsorption, low adsorption amount and long equilibrium time, and it is difficult to effectively remove a variety of heavy metal ions.
By synthesizing carboxyl functionalized mesoporous materials, SBA-15 is modified with malonic acid to produce materials with excellent heavy metal adsorption capabilities. This material significantly improves the adsorption effect by forming a complex with metal ions.
This material has obvious effects in adsorbing heavy metal ions such as Ca2+, Mg2+, Fe3+, Cu2+, Cr3+ and Zn2+, significantly improving the adsorption capacity and efficiency.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of nanomaterials, and in particular to a method for synthesizing a carboxyl functionalized mesoporous material. Background Art
[0002] Heavy metals are a type of toxic and harmful pollutants. Heavy metal ion pollutants in wastewater mainly come from waste liquids and waste residues generated during factory production and sewage generated by people's lives. In particular, roasting and smelting, manufacturing of various drugs, chemical processes, paper manufacturing, electrolysis and electroplating processes will produce a large amount of sewage, which contains a large amount of heavy metal ions such as cadmium, copper, mercury, lead, and zinc. Chemical precipitation, electrolysis, ion chromatography, ultrafiltration, adsorption and other methods are usually used to remove heavy metal ions from wastewater. Among them, the adsorption method uses the structure and properties of porous materials to adsorb and treat heavy metal ions in sewage to achieve the effect of purification. This method has the advantages of low cost, obvious adsorption effect, easy operation and no secondary pollution.
[0003] Commonly used adsorbents include activated carbon, graphene oxide, zeolite, ultrafiltration membrane, etc. However, they all have problems such as poor selective adsorption of target pollutants, low adsorption capacity, and long equilibrium time. SBA-15 has a uniform pore structure, simple synthesis method, large total area per unit mass, good heat resistance, and easy modification by other material groups, which makes it have great application potential in catalysis, adsorption and separation. In recent years, SBA-15 mesoporous composite materials have attracted much attention in the adsorption of heavy metal ions.
[0004] Malonic acid is a small molecule organic dibasic acid with a certain complexing ability. Malonic acid is a dibasic acid with typical reactivity of dibasic acids. For example, the methylene group of malonic acid is active and can undergo addition, alkylation, amination, halogenation and other reactions; its two carboxyl groups are very close to each other and can be dehydrated; it can undergo esterification with alcohol; decarboxylation by heating; condensation with carbonyl compounds; and addition with compounds containing active double bonds. In order to further improve the ability of SBA-15 to adsorb metal ions, the present invention further modifies SBA-15 with malonic acid to further improve its adsorption performance. Summary of the invention
[0005] 1. Technical problems to be solved: In view of the above technical problems, the present invention provides a method for synthesizing a carboxyl functionalized mesoporous material.
[0006] 2. Technical solution: A method for synthesizing a carboxyl functionalized mesoporous material comprises the following steps: S1: Synthesis of carboxyl-containing organosilicon precursor: 3-Chloropropyltrimethoxysilane and malonic acid are dissolved in chloroform, heated under reflux for reaction, and after the reaction is completed, the solvent is removed to obtain an oily substance, which is a carboxyl-containing organosilicon precursor; S2: PEO-PPO-PEO triblock copolymer (P123) was weighed and dissolved in deionized water, and the mixture was stirred vigorously to dissolve the mixture, and hydrochloric acid solution was added, and the mixture was kept at 35-40°C for 0.5-1h. A mixed silicon source solution of tetraethoxysilane (TEOS) and a carboxyl-containing organosilicon precursor was slowly added dropwise under vigorous stirring; the reaction mixture was stirred at 35-40°C for 20-30h to obtain a suspension; S3: Cool to room temperature, then transfer to a high-pressure reactor, and heat in an oven at 110-120°C for 40-60h; after cooling to room temperature, collect the precipitated solid, wash with deionized water, dry, and then heat and reflux with anhydrous ethanol as a solvent, and filter to obtain a solid, namely the carboxyl functionalized mesoporous material.
[0007] Furthermore, the molar ratio of 3-chloropropyltrimethoxysilane to malonic acid in S1 is 1:1.
[0008] Furthermore, an acid binding agent is added to the mixed solution in S1, and the acid binding agent includes sodium bicarbonate, sodium carbonate or sodium hydroxide. After the reaction is completed, the mixed solution is washed with water, dried and concentrated to remove the solvent.
[0009] Further, the molar ratio of the PEO-PPO-PEO triblock copolymer to the mixed silicon source in S2 is 5-7:10.
[0010] Furthermore, the organosilicon precursor in S2 accounts for 2%-10% of the mixed silicon source.
[0011] Furthermore, the molar ratio of HCl to the mixed silicon source in the hydrochloric acid in S2 is 1:5-10.
[0012] Furthermore, the molar ratio of deionized water to mixed silicon source in S2 is 200-250:1.
[0013] 3. Beneficial effects: The present invention provides a method for synthesizing a carboxyl functionalized mesoporous material. The active methylene group of malonic acid and 3-chloropropyltrimethoxysilane are used to prepare a carboxyl-containing organosilicon precursor, and the precursor is further reacted with tetraethoxysilane (TEOS) under the action of a template agent PEO-PPO-PEO triblock copolymer (P123) to generate a carboxyl functionalized mesoporous material having excellent heavy metal adsorption capacity, especially Ca 2+ Mg 2+ , Fe 3+ , Cu 2+ Cr 3+ and Zn2+ The adsorption effect is obvious. DETAILED DESCRIPTION
[0014] The present invention is described in detail below.
[0015] Embodiment 1: A method for synthesizing a carboxyl functionalized mesoporous material comprises the following steps: S1: Synthesis of carboxyl-containing organosilicon precursor: 3-Chloropropyltrimethoxysilane (10 g, 50.32 mmol) and malonic acid (5.24 g, 50.32 mmol) were dissolved in chloroform (150 mL), heated under reflux at 62 °C for reaction, 4 g of sodium bicarbonate was added as an acid binding agent, and after the reaction was completed, the oily substance was filtered and concentrated to obtain the carboxyl-containing organosilicon precursor; S2: PEO-PPO-PEO triblock copolymer (5 g, 15 mmol) was weighed and dissolved in 60 mL of deionized water, and 150 g of 2 M hydrochloric acid solution was added. The mixture was kept at 35-40 °C for 0.5-1 h, and a mixed silicon source solution of tetraethoxysilane (8 g, 38 mmol) and a carboxyl-containing organosilicon precursor (0.43 g, 1.6 mmol) was slowly added dropwise under vigorous stirring. The reaction mixture was stirred at 38 °C for 25 h to obtain a suspension. S3: Cool to room temperature, then transfer to a high-pressure reactor and heat in an oven at 115°C for 48 hours; after cooling to room temperature, collect the precipitated solid, wash with deionized water, dry, and heat under reflux with anhydrous ethanol as solvent, and filter to obtain a solid.
[0016] Embodiment 2: A method for synthesizing a carboxyl functionalized mesoporous material comprises the following steps: The first step has the same conditions as S1 in Example 1; the difference between the second step and S2 in Example 1 lies in the proportion of the carboxyl-containing organosilicon precursor in the mixed silicon source, which is 4% in Example 1 and 6% in this example, including tetraethoxysilane (8 g, 38 mmol) and organosilicon precursor (0.64 g, 2.4 mmol).
[0017] Embodiment 3: A method for synthesizing a carboxyl functionalized mesoporous material comprises the following steps: The first step has the same conditions as S1 in Example 1; the second step differs from S2 in Example 1 in that the proportion of the organosilicon precursor in the mixed silicon source is 4% in Example 1, while in this example, tetraethoxysilane (8 g, 38 mmol) and the organosilicon precursor (0.88 g, 3.3 mmol) account for 8%.
[0018] Test Example 1: The carboxyl functionalized mesoporous material was dispersed in water to prepare a 1 mg / mL suspension, and an excess of aqueous solution containing different metal ions, including K + , Ca 2+ 、Na + Mg 2+ 、Al 3+ Cr 3+ , Fe 3+ , Cu 2+ 、Zn 2+ 、Cd 2+ , Pb 2+ 、Co 2+ , and recorded its luminescence characteristics under a 365nm UV analyzer, in which Ca 2+ Mg 2+ , Fe 3+ , Cu 2+ Cr 3+ and Zn 2+ The fluorescence intensity and luminescence color change significantly, indicating that carboxyl-functionalized mesoporous materials have a strong coordination effect on these metal ions and have application prospects in the fields of sensors, catalysts and water treatment technology.
[0019] Although the present invention has been disclosed as above in terms of preferred embodiments, they are not intended to limit the present invention. Anyone skilled in the art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims of this application.
Claims
1. A method for synthesizing a carboxyl functionalized mesoporous material, characterized in that: The following steps are involved: S1: Synthesis of carboxyl-containing organosilicon precursor: 3-Chloropropyltrimethoxysilane and malonic acid are dissolved in chloroform, heated under reflux for reaction, and after the reaction is completed, the solvent is removed to obtain an oily substance, which is a carboxyl-containing organosilicon precursor; S2: PEO-PPO-PEO triblock copolymer (P123) was weighed and dissolved in deionized water, and the mixture was stirred vigorously to dissolve the mixture, and hydrochloric acid solution was added, and the mixture was kept at 35-40°C for 0.5-1h. A mixed silicon source solution of tetraethoxysilane (TEOS) and a carboxyl-containing organosilicon precursor was slowly added dropwise under vigorous stirring; the reaction mixture was stirred at 35-40°C for 20-30h to obtain a suspension; S3: Cool to room temperature, then transfer to a high-pressure reactor, and heat in an oven at 110-120°C for 40-60h; after cooling to room temperature, collect the precipitated solid, wash with deionized water, dry, and then heat and reflux with anhydrous ethanol as a solvent, and filter to obtain a solid, i.e., the carboxyl functionalized mesoporous material.
2. The method for synthesizing a carboxyl functionalized mesoporous material according to claim 1, characterized in that: The molar ratio of 3-chloropropyltrimethoxysilane to malonic acid in S1 is 1:
1.
3. A method for synthesizing a carboxyl functionalized mesoporous material according to claim 1 or 2, characterized in that: An acid-binding agent is added to the mixed solution in S1, and the acid-binding agent includes sodium bicarbonate, sodium carbonate or sodium hydroxide. After the reaction is completed, the mixed solution is washed with water, dried and concentrated to remove the solvent.
4. The method for synthesizing a carboxyl functionalized mesoporous material according to claim 3, characterized in that: The molar ratio of the PEO-PPO-PEO triblock copolymer to the mixed silicon source in S2 is 5-7:
10.
5. The method for synthesizing a carboxyl functionalized mesoporous material according to claim 4, characterized in that: The organosilicon precursor in S2 accounts for 2%-10% of the mixed silicon source.
6. The method for synthesizing a carboxyl functionalized mesoporous material according to claim 5, characterized in that: The molar ratio of HCl to the mixed silicon source in the hydrochloric acid in S2 is 1:5-10.
7. A method for synthesizing a carboxyl functionalized mesoporous material according to any one of claims 4 to 6, characterized in that: The molar ratio of deionized water to mixed silicon source in S2 is 200-250:1.