CN112938992B - A kind of preparation method of silica nano bowl - Google Patents

Abstract

The invention discloses a preparation method of a silicon dioxide nanometer bowl, which comprises the following steps: 1) sequentially adding 90-99.9 parts by weight of water and 0.1-10 parts by weight of PAANa into a reactor, and stirring to obtain a solution 1; 2) sequentially adding 0.1-10 parts of hydroxide and 0.3-10 parts (by weight) of ammonia water into 100ml of water, and stirring to obtain a solution 2; 3) adding 1-10 parts (by weight) of solution 1 into 150 parts of ethanol/water mixed solution with the concentration of 40-80%, and stirring to obtain solution 3; 4) slowly adding 0.3-30 parts by weight of the solution 2 and 3-25 parts by weight of tetraethoxysilane into the solution 3, and stirring; 5) slowly dripping inorganic acid into the solution obtained in the step 4), stirring, and adjusting the pH value of the solution to 2.0-3.0; 6) and after stirring is finished, drying to obtain the silicon dioxide nanometer bowl. The invention utilizes different dissolution characteristics of acid-base environments to obtain the silicon dioxide nanometer bowl material which is used as a carrier of the catalyst and is convenient to release.

Description

A kind of preparation method of silica nano bowl

technical field

The invention relates to a preparation method of a silicon dioxide nano bowl.

Background technique

Silica is commonly known as glass. Because of its extremely stable physical and chemical properties, large specific surface area, strong surface adsorption, large surface energy, high chemical purity, good dispersion performance, thermal resistance, electrical resistance and other specific properties, it is widely used in many disciplines. It has an irreplaceable role in the field and is widely used in various industries as catalyst carriers, petrochemicals, decolorizers, matting agents, rubber reinforcing agents, plastic fillers, ink thickeners, metal soft polishing agents, insulation. Insulation fillers, advanced daily cosmetic fillers and spraying materials, medicine, environmental protection and other fields. In particular, nano-silica balls can be used in catalysis, stabilizers, enhancers, additives, adsorbents, optoelectronics, biology and other fields. Application No. 201810674615.0 discloses a preparation method of nano-silica balls. , ethyl orthosilicate and an alcohol solution are mixed to obtain a nano-silica ball suspension; the nano-silica ball suspension is centrifugally washed, and the precipitate is dried to obtain the nano-silica ball.

On the other hand, compared with solid nanomaterials, nanoshell structures can usually exhibit superior properties and thus have wider application value. The hollow structure can be used as an inner space, providing more possibilities for the superposition, storage, transportation, etc. of the magnetic, optical, mechanical, thermal, electrical, and catalytic functions of the material.

At present, the hard template method is one of the simplest and most effective methods for removing hollow core-shell materials. It is widely used due to its simplicity, high repetition rate, good predictability, uniform product morphology, and stable performance. Generally, carbon spheres, silicon spheres or PS spheres are used as templates, and a layer of shell structure is coated on it, and then the core is removed by certain means to obtain a hollow structure. However, such a method generally requires many steps, which is not conducive to large-scale production.

In order to solve the above-mentioned problems, the present invention is hereby made.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a preparation method of silica nano bowl. Using the characteristics of sodium polyacrylate (PAANa) precipitation in an alkaline solution, the pH value is dissolved at a specific value (pH is about 2.5), and by controlling the process of sodium polyacrylate precipitation (alkaline) to dissolution (acidic), Induced self-assembly of nano-silica spheres into silica nano-bowls.

This objective is achieved through the following technical solutions:

A preparation method of silicon dioxide nano bowl, comprising the steps:

1) in the reactor, successively add 90-99.9 parts (weight ratio) of water and 0.1-10 parts (weight ratio) PAANa, and stir to obtain solution 1;

2) successively adding the hydroxide of 0.1-10 parts (weight ratio) and the ammonia water of 0.3-10 parts (weight ratio) to 100ml of water, and stirring to obtain solution 2;

3) in 150 parts (by weight) concentration of 40-80% ethanol/water mixed solution, add 1-10 parts (by weight) of solution 1, and stir to obtain solution 3;

4) 0.3-30 parts (weight ratio) of solution 2 and 3-25 parts (weight ratio) of ethyl orthosilicate are slowly added to solution 3, and stirring is performed;

5) Slowly add the mineral acid dropwise to the solution obtained in step 4), carry out stirring treatment, adjust the pH value of the solution to between 2.0 and 3.0, and fully stir to obtain a silica nano bowl.

Preferably, the stirring in step 1) is carried out under dark/no light conditions.

Further, the hydroxide in step 2) is magnesium hydroxide.

Preferably, the above-mentioned inorganic acid in step 5) is hydrochloric acid, and the pH value of the above-mentioned solution is 2.5.

Further, in step 5), after fully stirring, the silica nano bowl is obtained by centrifugation and washing with absolute ethanol, followed by drying.

Preferably, in step 5), stir for 30-150 minutes.

In one embodiment, in step 1), the weight ratio of water and PAANa is 95 parts: 5 parts.

Preferably, in step 2), the weight ratio of hydroxide and ammonia water is 5 parts: 5 parts.

Preferably, in step 3), the weight ratio of the 60% ethanol/water mixture to the solution 1 obtained in step 1) is 150 parts: 5 parts.

Preferably, in step 4), the weight ratio of solution 2 obtained in step 2) and solution 3 obtained in step 3) is 15 parts: 14 parts.

Beneficial technical effects:

1. The silica nano-bowl prepared by the present invention has an open structure, which can be used as a carrier of a catalyst to carry a large-capacity catalytic substance, and is easy to load and release.

2. The silica nano bowl prepared by the present invention can also be filled with other functional substances, which broadens the application value and scope. The product has a simple preparation process, easy control of conditions, and easy mass industrial production.

Description of drawings

Figure 1 is a scanning electron microscope image of the silica nano bowl, the scale in the figure is 1 μm, and the magnification is 20.00K.

Figure 2 is a scanning electron microscope image of the silica nano bowl, the scale in the figure is 1 μm, and the magnification is 10.00K.

Detailed ways

The present invention is further described below in conjunction with the specific embodiments and the accompanying drawings, so that those skilled in the art can better understand the technical solutions of the present invention.

Example 1

A preparation method of silicon dioxide nano bowl, comprising the steps:

1) in the reactor, successively add 90 parts (weight ratio) of water and 0.1 part (weight ratio) of PAANa, and stir for 5 minutes to obtain solution 1;

2) adding 0.1 part (weight ratio) of magnesium hydroxide and 0.3 part (weight ratio) ammoniacal water to 100ml water successively, and stirring for 5 minutes to obtain solution 2;

3) In 150 parts (weight ratio) concentration of 40% ethanol/water mixed solution, add 1 part of solution 1, and stir for 5 minutes to obtain solution 3;

4) 0.3 parts (weight ratio) of solution 2 and 3 parts (weight ratio) of ethyl orthosilicate (TEOS) were slowly added to solution 3, and stirred for 3 hours;

5) Slowly add hydrochloric acid dropwise to the solution obtained in step 4), carry out stirring treatment, adjust the pH value of the solution to 2.5, and obtain the above-mentioned silica nano bowl after fully stirring and drying.

This method utilizes the characteristics of sodium polyacrylate (PAANa) precipitation in alkaline solution and dissolves at PH=2.5, and induces nano-dioxide by regulating the process of sodium polyacrylate precipitation (alkaline) turning into dissolution (acidic). The silicon spheres self-assemble into a bowl-shaped structure with one end open, namely a silica nano-bowl.

Referring to FIG. 1 , the SEM image of the silicon dioxide nano bowl prepared in this example, the scale in the figure is 1 μm, and the magnification is 20.00K.

Referring to FIG. 2 , the SEM image of the silicon dioxide nano bowl prepared in this example, the scale in the figure is 1 μm, and the magnification is 10.00K.

Example 2

A preparation method of silicon dioxide nano bowl, comprising the steps:

1) In the brown bottle covered with tin foil, add 99.9 parts (by weight) of water and 10 parts by weight (by weight) of PAANa successively, and stir for 15 minutes to obtain solution 1;

2) 10 parts (weight ratio) of magnesium hydroxide and 10 parts (weight ratio) of ammoniacal water are successively added to 100ml water, stirred for 15 minutes to obtain solution 2;

3) in 150 parts (weight ratio) concentration of 80% ethanol/water mixed solution, add 10 parts (weight ratio) solution 1, stir for 15 minutes to obtain solution 3;

4) 30 parts (weight ratio) of solution 2 and 25 parts (weight ratio) of ethyl orthosilicate (TEOS) were slowly added to solution 3, and stirred for 13 hours;

5) Slowly add hydrochloric acid dropwise to the solution obtained in step 4), carry out stirring treatment, adjust the pH value of the solution to 2.0, and obtain the above-mentioned silica nano bowl after fully stirring and drying.

Example 3

A preparation method of silicon dioxide nano bowl, comprising the steps:

1) In the brown bottle covered by tin foil shading, add 95 parts (by weight) of water and 5 parts by weight of PAANa successively, and stir for 10 minutes to obtain solution 1;

2) 5 parts (weight ratio) of potassium hydroxide, 5 parts (weight ratio) of ammoniacal liquor are successively added to 100ml water, stirred for 10 minutes to obtain solution 2;

3) in 150 parts (weight ratio) concentration is 60% ethanol/water mixed solution, add 5 parts (weight ratio) solution 1, stir for 10 minutes to obtain solution 3;

4) 15 parts (weight ratio) of solution 2 and 14 parts (weight ratio) of ethyl orthosilicate (TEOS) were slowly added to solution 3, and stirred for 13 hours;

5) Slowly add hydrochloric acid dropwise to the solution obtained in step 4), carry out stirring treatment, adjust the pH value of the solution to 3.0, and obtain the above-mentioned silica nano bowl after fully stirring and drying.

Example 4

A preparation method of silicon dioxide nano bowl, comprising the steps:

1) In the brown bottle covered by tin foil shading, add 90 parts (by weight) of ultrapure water and 0.1 part (by weight) of PAANa successively, and stir for 5 minutes to obtain solution 1;

2) 10 parts of (weight ratio) calcium hydroxide, 0.3 parts (weight ratio) of ammoniacal water are added to 100ml ultrapure water successively, stirred for 5 minutes to obtain solution 2;

3) in 150 parts (weight ratio) concentration of 80% ethanol/ultrapure water mixed solution, add 1 part (weight ratio) solution 1, stir for 5 minutes to obtain solution 3;

4) 0.3 parts (weight ratio) of solution 2 and 25 parts (weight ratio) of ethyl orthosilicate (TEOS) were slowly added to solution 3, and stirred for 13 hours;

5) slowly add hydrochloric acid dropwise to the solution obtained by step 4), carry out stirring treatment, adjust the pH value of this solution to 2.2, carry out centrifugation treatment, wash 3 times with absolute ethanol, and obtain silicon dioxide nanometer after drying bowl.

Example 5

A preparation method of silicon dioxide nano bowl, comprising the steps:

1) In the brown bottle covered by tin foil shading, add 99.9 parts (by weight) of ultrapure water and 10 parts by weight (by weight) of PAANa successively, and stir for 15 minutes to obtain solution 1;

2) the magnesium hydroxide of 0.1 part (weight ratio), the ammoniacal liquor of 10 parts (weight ratio) are added into 100ml ultrapure water successively, stirred 15 minutes to obtain solution 2;

3) in 150 parts (weight ratio) concentration of 40% ethanol/ultrapure water mixed solution, add 10 parts (weight ratio) solution 1, stir 15 minutes to obtain solution 3;

4) 30 parts (weight ratio) of solution 2 and 3 parts (weight ratio) of ethyl orthosilicate are slowly added to solution 3, stirred for 3 hours;

5) Slowly add hydrochloric acid dropwise to the solution obtained by step 4), carry out stirring treatment, adjust the pH value of this solution to 2.8, carry out centrifugation treatment, wash 3 times with absolute ethanol, and obtain silicon dioxide nanometer after drying. bowl.

Example 6

A preparation method of silicon dioxide nano bowl, comprising the steps:

1) In the brown bottle covered with tin foil, add 90 parts (by weight) of ultrapure water and 10 parts by weight (by weight) of PAANa successively, and stir for 5 minutes to obtain solution 1;

2) the magnesium hydroxide of 0.1 part (weight ratio), the ammoniacal liquor of 10 parts (weight ratio) are added into 100ml ultrapure water successively, stirred 15 minutes to obtain solution 2;

3) in 150 parts (weight ratio) concentration of 40% ethanol/ultrapure water mixed solution, add 10 parts of solution 1, stir for 15 minutes to obtain solution 3;

4) 30 parts (weight ratio) of solution 2 and 3 parts (weight ratio) of ethyl orthosilicate are slowly added to solution 3, stirred for 13 hours;

5) Slowly add hydrochloric acid dropwise to the solution obtained by step 4), carry out stirring treatment, adjust the pH value of this solution to 2.1, carry out centrifugation treatment, wash 3 times with absolute ethanol, and obtain nano-silica after drying. bowl.

Claims (10)

1. a preparation method of silicon dioxide nano bowl, is characterized in that: comprise the steps: 1) in the reactor, successively add 90-99.9 parts by weight of water and 0.1-10 parts by weight of PAANa, and stir to obtain solution 1; 2) successively adding the hydroxide of 0.1-10 parts by weight and the ammonia water of 0.3-10 parts by weight into 100ml ultrapure water, and stirring to obtain solution 2; 3) in 150 parts by weight of ethanol/water mixed solution with a concentration of 40-80%, add 1-10 parts by weight of solution 1, and stir to obtain solution 3; 4) slowly adding the solution 2 of 0.3-30 parts by weight and the ethyl orthosilicate of 3-25 parts by weight in solution 3, stirring and processing; 5) Slowly add the inorganic acid dropwise to the solution obtained in step 4), perform stirring treatment, adjust the pH value of the solution to between 2.0 and 3.0, and fully stir to obtain a silica nano bowl. 2. The preparation method of silicon dioxide nano bowl according to claim 1, wherein the stirring in step 1) is carried out under dark light/no light conditions. 3. the preparation method of silica nano bowl according to claim 2, is characterized in that, the hydroxide in step 2) is magnesium hydroxide. 4. The preparation method of silicon dioxide nano bowl according to claim 3, wherein the above-mentioned inorganic acid in step 5) is hydrochloric acid, and the pH value of the above-mentioned solution is 2.5. 5. The preparation method of silicon dioxide nano bowl according to claim 4, is characterized in that, in step 5), after fully stirring, carry out drying treatment to obtain silicon dioxide nano bowl by centrifuging and washing with absolute ethanol. 6. The preparation method of silica nano bowl according to claim 5, is characterized in that, in step 5), stir for 30-150 minutes. 7. The preparation method of silicon dioxide nano bowl according to claim 1, is characterized in that, comprises the following steps: In step 1), the weight ratio of water and PAANa is 95 parts: 5 parts. 8. the preparation method of silicon dioxide nano bowl according to claim 7, is characterized in that, in step 2), the weight ratio of hydroxide and ammoniacal liquor is 5 parts: 5 parts. 9. the preparation method of silicon dioxide nano bowl according to claim 8, is characterized in that, In step 3), the weight ratio of the 60% ethanol/water mixture to the solution 1 obtained in step 1) is 150 parts: 5 parts. 10. the preparation method of silicon dioxide nano bowl according to claim 9, is characterized in that, In step 4), the weight ratio of solution 2 obtained in step 2) and solution 3 obtained in step 3) is 15 parts: 14 parts.

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