Preparation process of monodispersive silica sol

A technology of silica and monodispersity, applied in the direction of silica, silica, etc., can solve the problem of difficult preparation of monodisperse silica sol particles, difficulty in precisely controlling the addition speed of silica powder, and difficulty in preparing small particle size silica Sol and other problems, to achieve the effect of low cost, good product quality and good operation controllability

Active Publication Date: 2010-05-19
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This patent can obtain silica sol with a particle size greater than 5 nanometers, but the patent does not propose a method for controlling the particle size distribution to achieve a controllable particle size distribution
At the same time, in the experiment, we found that it is difficult to prepare silica sol particles with high monodispersity, especially it is difficult to prepare silica sol with small particle size with particle deviation less than 5% by adding silica powder in batches.
However, due to the certain viscosity between the finer silica powder particles, it is difficult to precisely control the addition speed of the silica powder by using the method of adding silica powder and lye at the same time, which will easily lead to large deviations in the final silica sol particles.

Method used

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  • Preparation process of monodispersive silica sol
  • Preparation process of monodispersive silica sol
  • Preparation process of monodispersive silica sol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] (1) Take 2000 grams of distilled water and add it to a reactor equipped with a reflux condenser, add 250 grams of 200-mesh commercial silicon powder and 5 grams of sodium hydroxide, start the stirrer and heat up to 75 ° C;

[0035] (2) take by weighing 10 grams of sodium hydroxide and join in 1000 grams of distilled water;

[0036] (3) Slowly add the lye obtained in the above step (2) into the mixed solution obtained in the step (1), and control the initial addition rate to be 250 grams of solution per hour. Then gradually increase the speed of adding lye, and finish adding in about 3 hours. Then continue to react for 2-3 hours. When the solution is cooled to 50°C, filter or centrifuge to obtain nano-silica sol.

[0037] The particle diameter measured by a dynamic light scattering laser particle size and potential analyzer is 18 nanometers, see figure 1 , where the abscissa is the particle size, and the ordinate is the percentage of different particles. SiO 2 The c...

Embodiment 2

[0039] (1) Get 300 grams of the silica sol solution gained in Example 1 and add it to 1700 grams of distilled water. Start the stirrer and heat to 80°C;

[0040] (2) Add 100 grams of commercially available 300 mesh silicon powder and stir;

[0041] (3) Take by weighing 15 grams of sodium hydroxide and join in 1000 grams of distilled water, then add 10 grams of ammonia water, mix well;

[0042] (4) Slowly add the lye obtained in step (3) into the mixed solution obtained in step (2), finish adding in about 4 hours, and continue to react for 1 hour;

[0043] (5) continue to add 225 grams of silicon powder in step (4) gained mixed solution, stir;

[0044] (6) Weigh 20 grams of NaOH, add it to 1500 grams of distilled water, and mix evenly; slowly add the lye to the mixed solution obtained in step (5), and add it in about 8 hours. Continue to react for 2 to 3 hours. When the solution is cooled to 50°C, it is filtered or centrifuged to obtain nano-silica sol.

[0045] The partic...

Embodiment 3

[0047] (1) Take 2000 grams of distilled water and add it to a reactor equipped with a reflux condenser, add 150 grams of 200-mesh commercially available silicon powder and 5 grams of sodium hydroxide, start the stirrer and heat up to 75 ° C;

[0048] (2) Take by weighing 10 grams of sodium hydroxide and join in 1000 grams of distilled water, then add 10 grams of ammonia water, mix well;

[0049] (3) Slowly add the lye obtained in the above step (2) into the mixed solution obtained in the step (1), and control the initial addition rate to be 150 grams of solution per hour. Then gradually increase the speed of adding lye, and finish adding in about 6 hours. Then continue to react for 1 hour;

[0050] (4) Add 500 grams of silicon powder in the above solution, and continue to stir;

[0051] (5) Take by weighing 45 grams of NaOH, join in 2500 grams of water, mix well;

[0052] (6) Add lye as shown in step (3), and add it in about 8 hours. Continue to react for 2 to 3 hours. Wh...

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Abstract

The present invention discloses one kind of nanometer monodispersive silica sol prepared with metal silicon powder and through reaction with water under the catalysis of certain amount of alkali catalyst at temperature of 50-95 deg.c. During the preparation, alkali solution adding speed is so controlled that the newly produced silicon sol precursor concentration is in the new nucleus forming concentration. Compared with available silica sol preparing process, the present invention has the advantages of homogeneous size distribution of nanometer silica sol, capacity of designing the sol size, simple preparation process, low cost and easy precise control.

Description

technical field [0001] The invention relates to nonmetal elements and compounds thereof, in particular to a method for preparing monodisperse nanometer silicon dioxide sol. Background technique [0002] Nano-silica sol is a colloidal solution formed by uniformly dispersing aggregated particles of amorphous silica in a solvent. Due to its large specific surface area, high adsorption performance, chemical stability and other excellent properties, it is widely used as a widely used inorganic polymer material in chemical, material, textile / paper, electronics and other industries. In recent years, silica sol has also been used in the medical field, such as toothpaste, dental casting and drug delivery system. [0003] At present, the preparation methods of silica sol include silica powder dissolution method, ion exchange method, electrolytic electrodialysis method, peptization method, dispersion method and silicate hydrolysis method. However, the preparation methods of silica so...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/14
Inventor 郭建军崔平李勇张怡陈林
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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