A preparation method of surface modified silicon dioxide adsorption material

Abstract

The invention relates to the technical field of silicon dioxide, and discloses a preparation method of a surface-modified silicon dioxide adsorbent. The preparation method comprises the following steps: adding water and sodium sulfonate-modified silicon dioxide into a flask, stirring, adding a polyquaternary ammonium salt modifier, stirring, filtering, washing, and drying to obtain the surface-modified silicon dioxide adsorbent. The invention uses anion and cation electrostatic self-assembly to modify the polyquaternary ammonium salt modifier onto the surface of nano silicon dioxide, thereby introducing a large amount of quaternary ammonium salt cationic groups onto the surface of nano silicon dioxide, having a strong electrostatic interaction with anionic dye pollutants such as methyl orange, Congo red, and sunset yellow, and exhibiting excellent adsorption performance and removal efficiency. The invention has good practical application in the treatment of wastewater containing dye pollutants.

Description

Technical Field

[0001] The invention relates to the technical field of silicon dioxide, in particular to a method for preparing a surface-modified silicon dioxide adsorption material. Background Art

[0002] Nano silicon dioxide is cheap and easy to obtain, has a large specific surface area, is green and pollution-free, and has a variety of preparation methods. It can usually be prepared by precipitation from sodium silicate and sulfuric acid; or by hydrolysis of tetraethyl orthosilicate; and nano silicon dioxide is easy to be functionalized on the surface and is widely used in wastewater treatment, gas adsorption, etc. Surface modification of nano silicon dioxide and introduction of functional groups are effective methods to improve the adsorption performance of nano silicon dioxide. Patent CN106040180B discloses a modified nano silicon dioxide material and its preparation method and application, which uses silicon dioxide to react with dimethyl octadecyl [3-(trimethoxysilyl)propyl] ammonium chloride and ammonia water to obtain a nano silicon dioxide material with a surface grafted quaternary ammonium salt, which can adsorb anionic dyes in aqueous solution, but the adsorption rate of the nano silicon dioxide material to anionic dyes such as xylenol orange is low, which cannot meet its practical application in wastewater treatment.

[0003] Patent CN104045857B discloses a silicon dioxide chitosan composite material, preparation method and application thereof, wherein pyrenebutyric acid-modified chitosan is quaternized and then reacted with epoxy-modified silicon dioxide nanomaterials to obtain a multifunctional nanomaterial that can be used for mercury ion adsorption and detection. However, the silicon dioxide chitosan composite material of the patent does not show good adsorption performance for anionic dyes. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a surface-modified silica adsorption material for adsorbing dye pollutants.

[0005] Technical solution: A method for preparing a surface-modified silica adsorption material:

[0006] Step S1, add ethanol solvent and KH560 modified silica into a flask, add water and taurine after stirring, stir and reflux at 75-90° C. for 4-7 hours, then add sodium hydroxide to adjust the pH to 8-10, filter after stirring, wash with water, and dry to obtain sodium sulfonate modified silica.

[0007] Step S2: add water and sodium sulfonate modified silica to a flask, add a polyquaternary ammonium salt modifier after stirring, stir at room temperature for 3-6 hours, filter, wash with water, and dry to obtain a surface modified silica adsorption material. The reaction mechanism is as follows:

[0008]

[0009] Furthermore, in step S1, the mass of taurine is 15-40% of the mass of KH560 modified silica.

[0010] Furthermore, in step S2, the mass of the polyquaternary ammonium salt modifier is 80-250% of the mass of the sodium sulfonate modified silica.

[0011] Furthermore, the preparation method of the polyquaternary ammonium salt modifier comprises the following steps: placing a flask in an ice bath, adding dichloromethane, triethylenetetramine, (dimethylamino)acetyl chloride, and triethylamine, stirring and reacting at 15-25° C. for 24-36 hours, distilling under reduced pressure, washing with petroleum ether, then adding the product to acetonitrile, adding alkyl halide chloride, stirring and condensing and refluxing at 80-85° C. for 36-48 hours, distilling under reduced pressure, and recrystallizing the product in an ethanol aqueous solution with a volume fraction of 80% to obtain the polyquaternary ammonium salt modifier.

[0012]

[0013] Furthermore, the molar ratio of triethylenetetramine, (dimethylamino)acetyl chloride, triethylamine, and alkyl halide chloride is 1:(4-4.8):(4.4-4.8):(4-5.2).

[0014] Furthermore, the chemical formula of the alkyl halide chloride is Cl-C n H 2n+1 , where n is 2-6.

[0015] Furthermore, the preparation method of KH560 modified silica is as follows: toluene and nano-silica are added to a flask, ultrasonically dispersed, and then KH550 is added, stirred and reacted after heating, filtered, washed with ethanol, and dried to obtain KH560 modified silica.

[0016] The technical effect of the present invention is as follows: the present invention uses triethylenetetramine, (dimethylamino)acetyl chloride, alkyl halide chloride and the like as raw materials, and obtains a polyquaternary ammonium salt modifier containing multiple quaternary ammonium salt groups through amidation and quaternization reactions.

[0017] The invention utilizes taurine and the epoxy group of KH560 modified silicon dioxide to carry out ring-opening reaction to obtain sodium sulfonate modified silicon dioxide, thereby introducing sulfonate anions on the surface of nano silicon dioxide, and then modifying the surface of nano silicon dioxide with a multi-quaternary ammonium salt modifier through anion-cation electrostatic self-assembly, thereby realizing the introduction of a large number of quaternary ammonium salt cationic groups on the surface of nano silicon dioxide, having strong electrostatic interaction with anionic dye pollutants such as methyl orange, Congo red, sunset yellow, etc., and showing excellent adsorption performance and removal efficiency. The invention has good practical application in the treatment of wastewater containing dye pollutants. DETAILED DESCRIPTION

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The experimental methods in the following embodiments are conventional methods unless otherwise specified. The test materials used in the following embodiments are purchased from conventional biochemical reagent stores unless otherwise specified. In addition, except for the special instructions of this embodiment, the terms and processes involved in this embodiment are understood according to the general cognition and conventional methods in the prior art.

[0019] The KH560 of the present invention is γ-glycidyloxypropyltrimethoxysilane. The CAS number of (dimethylamino)acetyl chloride is 51552-16-0. The CAS number of triethylenetetramine is 112-24-3. The CAS number of taurine is 107-35-7.

[0020] At 65°C, 200 mL of a 0.3 mol / L sodium silicate aqueous solution was added dropwise into a flask, and concentrated sulfuric acid was added dropwise at the same time to adjust the solution pH to 9. The stirring rate was controlled to 800 r / min, and the reaction was performed for 90 min. After cooling, the mixture was centrifuged and washed with water, and the precipitate was added to ethanol, centrifuged and dried to obtain nano-silicon dioxide.

[0021] Add 50 mL of toluene and 2 g of nano-silica into a flask, disperse by ultrasonic, then add 0.12 g of KH550, heat to 80°C, stir and react for 10 h, filter, wash with ethanol, and dry to obtain KH560 modified silica.

[0022] Example 1

[0023] (1) Place a flask in an ice bath, add 60 mL of dichloromethane, 10 mmol of triethylenetetramine, 48 mmol of (dimethylamino)acetyl chloride, and 48 mmol of triethylamine, stir and react at 20° C. for 36 h, distill under reduced pressure, wash with petroleum ether, then add the product to 70 mL of acetonitrile, add 44 mmol of 1-chlorohexane, stir and condense under reflux at 85° C. for 36 h, distill under reduced pressure, and recrystallize the product in an ethanol aqueous solution with a volume fraction of 80% to obtain a polyquaternary ammonium salt modifier.

[0024] (2) Add 100 mL of ethanol solvent and 5 g of KH560 modified silica into a flask, stir and then add water and 0.75 g of taurine, stir and reflux at 80° C. for 4 h, then add sodium hydroxide to adjust the pH to 8, stir and then filter, wash with water, and dry to obtain sodium sulfonate modified silica.

[0025] (3) Add 60 mL of water and 2 g of sodium sulfonate-modified silica into a flask, add 1.6 g of a polyquaternary ammonium salt modifier after stirring, stir at room temperature for 3 h, filter, wash with water, and dry to obtain a surface-modified silica adsorption material.

[0026] Example 2

[0027] (1) Place a flask in an ice bath, add 50 mL of dichloromethane, 10 mmol of triethylenetetramine, 44 mmol of (dimethylamino)acetyl chloride, and 44 mmol of triethylamine, stir and react at 15° C. for 36 h, distill under reduced pressure, wash with petroleum ether, then add the product to 80 mL of acetonitrile, add 52 mmol of 1-chlorohexane, stir and condense under reflux at 80° C. for 36 h, distill under reduced pressure, and recrystallize the product in an ethanol aqueous solution with a volume fraction of 80% to obtain a polyquaternary ammonium salt modifier.

[0028] (2) Add 100 mL of ethanol solvent and 5 g of KH560 modified silica into a flask, stir and then add water and 1.22 g of taurine, stir and reflux at 90° C. for 4 h, then add sodium hydroxide to adjust the pH to 10, stir and then filter, wash with water, and dry to obtain sodium sulfonate modified silica.

[0029] (3) Add 70 mL of water and 2 g of sodium sulfonate-modified silica into a flask, add 2.8 g of a polyquaternary ammonium salt modifier after stirring, stir at room temperature for 4 h, filter, wash with water, and dry to obtain a surface-modified silica adsorption material.

[0030] Example 3

[0031] (1) Place a flask in an ice bath, add 40 mL of dichloromethane, 10 mmol of triethylenetetramine, 40 mmol of (dimethylamino)acetyl chloride, and 44 mmol of triethylamine, stir and react at 25° C. for 36 h, distill under reduced pressure, wash with petroleum ether, then add the product to 70 mL of acetonitrile, add 40 mmol of 1-chlorohexane, stir and condense under reflux at 85° C. for 36 h, distill under reduced pressure, and recrystallize the product in an ethanol aqueous solution with a volume fraction of 80% to obtain a polyquaternary ammonium salt modifier.

[0032] (2) Add 120 mL of ethanol solvent and 5 g of KH560 modified silica into a flask, stir and then add water and 1.64 g of taurine, stir and reflux at 75° C. for 7 h, then add sodium hydroxide to adjust the pH to 9, stir and then filter, wash with water, and dry to obtain sodium sulfonate modified silica.

[0033] (3) Add 70 mL of water and 2 g of sodium sulfonate-modified silica into a flask, add 3.8 g of a polyquaternary ammonium salt modifier after stirring, stir at room temperature for 6 h, filter, wash with water, and dry to obtain a surface-modified silica adsorption material.

[0034] Example 4

[0035] (1) Place a flask in an ice bath, add 40 mL of dichloromethane, 10 mmol of triethylenetetramine, 40 mmol of (dimethylamino)acetyl chloride, and 44 mmol of triethylamine, stir and react at 25° C. for 24 h, distill under reduced pressure, wash with petroleum ether, then add the product to 80 mL of acetonitrile, add 48 mmol of 1-chloropropane, stir and condense under reflux at 80° C. for 48 h, distill under reduced pressure, and recrystallize the product in an ethanol aqueous solution with a volume fraction of 80% to obtain a polyquaternary ammonium salt modifier.

[0036] (2) Add 120 mL of ethanol solvent and 5 g of KH560 modified silica into a flask, stir and then add water and 2 g of taurine, stir and reflux at 80° C. for 7 h, then add sodium hydroxide to adjust the pH to 8, stir and then filter, wash with water, and dry to obtain sodium sulfonate modified silica.

[0037] (3) Add 80 mL of water and 2 g of sodium sulfonate-modified silica into a flask, add 5 g of a polyquaternary ammonium salt modifier after stirring, stir at room temperature for 6 h, filter, wash with water, and dry to obtain a surface-modified silica adsorption material.

[0038] In Comparative Example 1, nano-silicon dioxide is used as the adsorption material.

[0039] In Comparative Example 2, KH560 modified silica was used as the adsorption material.

[0040] Comparative Example 3 uses sodium sulfonate-modified silica as the adsorption material (prepared by Example 1).

[0041] Comparative Example 4

[0042] (1) Add 60 mL of water and 2 g of sodium sulfonate-modified silica (prepared in Example 1) into a flask, stir, add 1.6 g of hexadecyltrimethylammonium chloride, stir at room temperature for 3 h, filter, wash with water, and dry to obtain a surface-modified silica adsorbent material.

[0043] Add 200 mL of water and methyl orange to a flask to prepare a methyl orange solution with a mass concentration of 50 mg / L, then add 80-200 mg of adsorption material, stir and adsorb at room temperature for 3 hours, determine the concentration of the methyl orange solution by ultraviolet spectrophotometer, and calculate the adsorption rate.

[0044] Adsorption rate W = (C0-C1) / C0×100%. C0 is the concentration of methyl orange solution before adsorption. C1 is the concentration of methyl orange solution after adsorption.

[0045] Table 1 Methyl orange adsorption rate test

[0046]

[0047] Add 200 mL of water and Congo red to a flask to prepare a Congo red solution with a mass concentration of 50 mg / L, then add 100-250 mg of adsorption material, stir and adsorb at room temperature for 3 hours, determine the concentration of the Congo red solution by ultraviolet spectrophotometer, and calculate the adsorption rate.

[0048] Adsorption rate W = (C0-C1) / C0×100%. C0 is the concentration of Congo red solution before adsorption. C1 is the concentration of Congo red solution after adsorption.

[0049] Table 2 Congo red adsorption rate test

[0050]

[0051] Add 200 mL of water and sunset yellow to a flask to prepare a sunset yellow solution with a mass concentration of 50 mg / L, then add 100-250 mg of adsorption material, stir and adsorb at room temperature for 3 hours, determine the concentration of the sunset yellow solution by ultraviolet spectrophotometer, and calculate the adsorption rate.

[0052] Adsorption rate W = (C0-C1) / C0×100%. C0 is the concentration of the sunset yellow solution before adsorption. C1 is the concentration of the sunset yellow solution after adsorption.

[0053] Table 3 Sunset yellow adsorption rate test

[0054]

[0055]

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a surface-modified silica adsorbent material, characterized in that: The preparation method comprises the following steps: Step S1, adding ethanol solvent and KH560 modified silica into a flask, stirring and then adding water and taurine, stirring and reacting, then adding sodium hydroxide, stirring and then filtering, washing, and drying to obtain sodium sulfonate modified silica; Step S2, adding water and sodium sulfonate modified silica into a flask, adding a polyquaternary ammonium salt modifier after stirring, stirring at room temperature for 3-6 hours, filtering, washing, and drying to obtain a surface modified silica adsorption material; The chemical structural formula of the polyquaternary ammonium salt modifier is: , where n is 2-6.

2. The method for preparing the surface-modified silica adsorbent material according to claim 1, characterized in that: The mass of taurine in step S1 is 15-40% of the mass of KH560 modified silica.

3. The method for preparing the surface-modified silica adsorbent material according to claim 1, characterized in that: In step S1, the reaction is condensed and refluxed at 75-90° C. for 4-7 hours.

4. The method for preparing the surface-modified silica adsorbent material according to claim 1, characterized in that: In step S1, sodium hydroxide is added to adjust the pH to 8-10.

5. The method for preparing the surface-modified silica adsorbent material according to claim 1, characterized in that: In the step S2, the mass of the polyquaternary ammonium salt modifier is 80-250% of the mass of the sodium sulfonate modified silica.

6. The method for preparing the surface-modified silica adsorbent material according to claim 1, characterized in that: The preparation method of the polyquaternary ammonium salt modifier comprises the following steps: placing a flask in an ice bath, adding dichloromethane, triethylenetetramine, (dimethylamino)acetyl chloride and triethylamine, carrying out an amidation reaction, performing reduced pressure distillation, washing with petroleum ether, then adding the product into acetonitrile, adding alkyl chloride, carrying out a quaternization reaction, performing reduced pressure distillation, and recrystallizing the product in an ethanol aqueous solution with a volume fraction of 80% to obtain the polyquaternary ammonium salt modifier.

7. The method for preparing the surface-modified silica adsorbent material according to claim 6, characterized in that: The molar ratio of triethylenetetramine, (dimethylamino)acetyl chloride, triethylamine and alkyl chloride is 1:(4-4.8):(4.4-4.8):(4-5.2).

8. The method for preparing the surface-modified silica adsorbent material according to claim 6, characterized in that: The chemical structural formula of the alkyl chloride is , where n is 2-6.

9. The method for preparing the surface-modified silica adsorbent material according to claim 6, characterized in that: The amidation reaction is carried out at 15-25° C. for 24-36 hours; the quaternization reaction is carried out at 80-85° C. for 36-48 hours under condensation reflux.

10. The method for preparing the surface-modified silica adsorbent material according to claim 2, characterized in that: The preparation method of the KH560 modified silica is as follows: toluene and nano-silica are added into a flask, ultrasonically dispersed, and then KH560 is added, heated, stirred and reacted, filtered, washed, and dried to obtain the KH560 modified silica.

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