Modified silica gel as well as preparation method and adsorption application method thereof
Through the preparation method of modified silica gel, ionic liquid and inorganic acid aqueous solution are used to form an ionic modified silica gel support and introduce thien groups, which solves the problems of insufficient activity of modified silica gel and complex production process, and achieves higher adsorption performance and Lower production costs.
Patent Information
- Application Number
- CN202411683015.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-22
- Publication Date
- 2025-02-18
AI Technical Summary
The existing modified silica gel has less activity, which leads to insufficient adsorption capacity of precious metals and complex production process, which increases production costs.
Modified silica gel with higher adsorption properties is prepared by mixing silica gel with ionic liquid and aqueous inorganic acid solution to form an ionically modified silica gel and introducing thien groups on its surface.
It significantly improves the surfactivity, affinity and selectivity of modified silica gel, enhances its adsorption ability to metals, reduces production costs, and is suitable for large-scale industrial applications.
Smart Images
Figure CN119455902A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic chemical silica gel preparation, and more specifically, to a modified silica gel and a preparation method and an adsorption application method thereof. Background Art
[0002] Precious metals mainly refer to gold, silver and platinum group metals (such as platinum, palladium, ruthenium, rhodium, iridium and osmium). Due to their excellent chemical stability, electrical conductivity and catalytic activity, they are widely used in many fields such as medicine, chemical industry, electroplating, electronics, national defense and military industry. However, in the application process of precious metals, a certain amount of metal residues will inevitably be produced, which may be left in the final product or discharged into industrial waste liquid. Such loss not only causes a waste of precious metal resources, but also may have a negative impact on the environment and human health. Metal ions in industrial waste liquid may cause water pollution and affect the balance of the ecosystem; and residual metal ions in medicines may pose a serious threat to human health.
[0003] With the rapid development of the global manufacturing industry, China has become the world's largest consumer of precious metals, and the recovery and recycling of precious metals have become increasingly important. In the prior art, modified silica gel, as an adsorbent for precious metals, has been widely used in the recovery and purification of precious metals due to its excellent physical and chemical properties and high stability. By utilizing the hydroxyl groups on the surface of silica gel to react with certain active groups to form modified silica gel, the modified silica gel can effectively complex heavy metal ions such as palladium, gold, platinum, yttrium, and rhodium. However, the existing technology of modified silica gel has some defects in practical applications. First, the activity of modified silica gel is relatively small, resulting in its insufficient adsorption capacity for precious metals, and poor adsorption performance for other metals other than precious metals, such as sodium ions and potassium ions. Secondly, the complexity of the modification process increases the production cost of modified silica gel. Based on the above statements, the present invention provides a modified silica gel and a preparation method and adsorption application method thereof. Summary of the invention
[0004] In order to solve the problems that the existing modified silica gel has low activity, resulting in insufficient adsorption capacity for metals, unable to meet the needs of industrial recycling, complicated modification process and high production cost, the present invention provides a modified silica gel and a preparation method and adsorption application method thereof.
[0005] In the first aspect, the present invention provides a modified silica gel, which adopts the following technical solution:
[0006] A modified silica gel is prepared by reacting silica gel as a raw material with a compound shown in formula I in a solvent;
[0007]
[0008] In the formula, R1, R2, and R3 are independently selected from C1-C12 straight chain or branched chain alkyl groups, and L is selected from C1-C6 straight chain or branched chain alkylene groups.
[0009] Preferably, R1, R2, and R3 are independently selected from methyl, ethyl, propyl, butyl or isopropyl.
[0010] Preferably, L is selected from methylene, 1,2-ethylene, n-propylene, n-butylene or 1,1-ethylene.
[0011] Preferably, the compound represented by formula I is selected from the following structures:
[0012]
[0013] In a second aspect, the present invention provides a method for preparing modified silica gel, which adopts the following technical scheme:
[0014] A method for preparing modified silica gel comprises the following preparation steps:
[0015] S1. After the silica gel and ionic liquid are evenly mixed, an inorganic acid aqueous solution is added, stirred at 100-150° C. for 1-2 hours, cooled to room temperature, filtered, washed with water until neutral, and dried to obtain a modified silica gel carrier;
[0016] S2. Under a protective gas atmosphere, the modified silica gel carrier and the compound represented by formula I are added to a solvent, heated to reflux reaction, cooled, filtered, washed, and dried to obtain modified silica gel.
[0017] Preferably, the silica gel particle size in step S1 is 200-300 mesh.
[0018] Preferably, the ionic liquid in step S1 is selected from 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride or 1-ethyl-3-methylimidazolium trifluoroacetate.
[0019] Preferably, the inorganic acid in step S1 is selected from at least one of hydrochloric acid, nitric acid and sulfuric acid.
[0020] Preferably, in step S1, the mass ratio of silica gel, ionic liquid and inorganic acid aqueous solution is 1:0.8-1.2:1-1.5; and the mass fraction of the inorganic acid aqueous solution is 4-8%.
[0021] Preferably, in step S2, the mass ratio of the modified silica gel carrier, the compound represented by formula I and the solvent is 12-14:60-65:1:7-8, and the solvent is toluene.
[0022] In a third aspect, the present invention provides an application of modified silica gel in metal adsorption.
[0023] In summary, the present invention has the following beneficial effects:
[0024] The present invention mixes silica gel and ionic liquid, adds an inorganic acid aqueous solution and stirs to react, thereby obtaining an ion-modified silica gel carrier; the synergistic effect of the ionic liquid and the inorganic acid significantly improves the surface activity, affinity and selectivity of the silica gel, and the obtained modified silica gel carrier is then reacted with a compound of formula I to obtain a modified silica gel. By introducing a specific functional group (thiophene group) on the surface of the modified silica gel carrier, the obtained modified silica gel can selectively complex with metal ions, thereby enhancing its adsorption of metals and improving the separation effect.
[0025] The preparation method of the present invention is relatively simple, and the materials used are easy to obtain, with low production cost, suitable for large-scale industrial applications. The obtained modified silica gel still maintains good structural stability at high temperatures, can withstand more harsh industrial environments, and is adaptable to a wider range of recycling applications. DETAILED DESCRIPTION
[0026] The present invention is further described in detail below with reference to the embodiments.
[0027] Unless otherwise specified, the materials, reagents, etc. used in the present invention can be obtained from commercial sources.
[0028] Among them, silica gel, particle size 200-300 mesh, model C, was purchased from Qingdao Chenrong New Materials Co., Ltd.
[0029] Embodiment 1-6 provides a modified silica gel and a preparation method and an adsorption application method thereof.
[0030] Example 1
[0031] Under nitrogen protection, add 100 g of silica gel, 500 ml of toluene, 8 g of triethylamine and 160 g of compound S1 into a three-necked flask, heat to reflux for 20 h, cool to room temperature, filter, wash with toluene, ethanol and deionized water in sequence, and dry at 80°C to obtain 102 g of modified silica gel; compound S1 is as follows:
[0032]
[0033] Example 2
[0034] The same as Example 1, except that the compound S1 is replaced by the compound S2 of the same mass, to prepare the modified silica gel.
[0035] Compound S2 is as follows:
[0036]
[0037] Example 3
[0038] The same method as Example 1 is different in that the compound S1 is replaced by the compound S3 of the same mass to prepare the modified silica gel.
[0039] Compound S3 is as follows:
[0040]
[0041] Example 4
[0042] The same method as Example 1 is different in that the compound S1 is replaced by the compound S5 of the same mass to prepare the modified silica gel.
[0043] Compound S5 is as follows:
[0044]
[0045] Example 5
[0046] The same as Example 1, except that the compound S1 is replaced by the compound S6 of the same mass, to prepare the modified silica gel.
[0047] Compound S6 is as follows:
[0048]
[0049] Example 6
[0050] 100 g of 1-ethyl-3-methylimidazolium tetrafluoroborate, 100 g of silica gel, and 100 g of 5% sulfuric acid were mixed and stirred evenly, heated to 100° C. and stirred for reaction for 2 h, cooled to room temperature, filtered, washed with deionized water, and dried at 80° C. to obtain 96 g of a modified silica gel carrier;
[0051] Under nitrogen protection, 96 g of the modified silica gel carrier, 500 ml of toluene, 8 g of triethylamine and 60 g of compound S1 were added to a three-necked flask, heated to reflux for 20 h, cooled to room temperature, filtered, washed with toluene, ethanol and deionized water in sequence, and dried at 80° C. to obtain 99 g of modified silica gel; compound S1 is as follows:
[0052]
[0053] In order to verify the comprehensive performance of the modified silica gel prepared in Examples 1-6 of the present invention, the applicant set up Comparative Example 1, which is as follows:
[0054] Comparative Example 1
[0055] The same as Example 1, except that the compound S1 is replaced by the compound D1 of the same mass, to prepare the modified silica gel; the compound D1 is as follows:
[0056]
[0057] Performance Testing
[0058] The metal ion adsorption performance of the modified silica gel prepared in Examples 1-6 of the present invention and Comparative Example 1 was tested respectively, as follows:
[0059] Take 100ml heavy metal aqueous solution (metal Pd 2+ Solution, initial concentration 20ppm, metal Cu 2+ Solution, initial concentration 20ppm, metal Na + The solution was prepared by mixing the mixture into a 0.2 g solution, with an initial concentration of 20 ppm, and 0.2 g of the modified silica gel prepared in Examples 1-6 and Comparative Example 1 was added as an adsorbent, respectively. The mixture was stirred at 25° C. for 0.5 h, filtered, and the metal ion content in the mother liquor after adsorption and filtration was determined in ppm. The results are shown in Table 1.
[0060] Table 1:
[0061] Adsorbent samples <![CDATA[Metallic Pd 2+ solution]]> <![CDATA[Metal Cu 2+ solution]]> <![CDATA[Sodium metal + solution]]> Example 1 1.8 3.2 19.9 Example 2 1.3 4.6 6.1 Example 3 1.9 3.1 18.7 Example 4 1.7 3.0 18.2 Example 5 2.1 0.5 16.2 Example 6 1.2 2.2 10.7 Comparative Example 1 4.0 6.6 18.6
[0062] From the data shown in Table 1 above, it can be seen that the comprehensive performance of the modified silica gel prepared in Examples 1-6 is significantly better than that of Comparative Example 1, and has obvious advantages in terms of adsorption selectivity and adsorption efficiency for precious metal ions, and has broad market prospects.
[0063] From the comparison between Example 1 and Example 6, it can be seen that the adsorption performance of the modified silica gel obtained by the reaction after being treated with the ionic liquid can be further improved.
[0064] It can be seen from Example 2 that the modified silica gel prepared using compound S2 has better adsorption performance for sodium ions.
[0065] It can be seen from Example 5 that the modified silica gel prepared using compound S6 has good adsorption performance for copper ions.
[0066] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.
Claims
1. A modified silica gel, characterized in that: Silica gel is used as a raw material, and reacts with a compound shown in formula I in a solvent to generate; In the formula, R1, R2, and R3 are independently selected from C1-C12 straight chain or branched chain alkyl groups, and L is selected from C1-C6 straight chain or branched chain alkylene groups.
2. The modified silica gel according to claim 1, characterized in that: The R1, R2, and R3 are independently selected from methyl, ethyl, propyl, butyl or isopropyl.
3. The modified silica gel according to claim 1, characterized in that: The L is selected from methylene, 1,2-ethylene, n-propylene, n-butylene or 1,1-ethylene.
4. The modified silica gel according to claim 1, characterized in that: The compound represented by formula I is selected from the following structures:
5. A method for preparing the modified silica gel according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. After the silica gel and the ionic liquid are evenly mixed, an inorganic acid aqueous solution is added, stirred at 100-150° C. for 1-2 hours, cooled to room temperature, filtered, washed with water until neutral, and dried to obtain a modified silica gel carrier; S2. Under a protective gas atmosphere, the modified silica gel carrier and the compound represented by formula I are added to a solvent, heated to reflux reaction, cooled, filtered, washed, and dried to obtain modified silica gel.
6. The method for preparing modified silica gel according to claim 5, characterized in that: In step S1, the ionic liquid is selected from 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride or 1-ethyl-3-methylimidazolium trifluoroacetate.
7. The method for preparing modified silica gel according to claim 5, characterized in that: In step S1, the inorganic acid is selected from at least one of hydrochloric acid, nitric acid and sulfuric acid.
8. The method for preparing modified silica gel according to claim 5, characterized in that: In the step S1, the mass ratio of silica gel, ionic liquid and inorganic acid aqueous solution is 1:0.8-1.2:1-1.5; the mass fraction of the inorganic acid aqueous solution is 4-8%.
9. The method for preparing modified silica gel according to claim 5, characterized in that: In the step S2, the mass ratio of the modified silica gel carrier, the compound represented by formula I and the solvent is 12-14:60-65:1:7-8, and the solvent is toluene.
10. Use of the modified silica gel according to any one of claims 1 to 4 in metal adsorption.