Silica nano-microsphere with controllable particle size and preparation method of silica nano-microsphere

Abstract

The invention discloses a particle size controllable silicon dioxide nano-microsphere and a preparation method thereof, and particularly relates to the technical field of preparation of silicon dioxide nano-microspheres, and the particle size controllable silicon dioxide nano-microsphere comprises a silicon dioxide nano-microsphere body. The invention relates to a preparation method of silicon dioxide nano-microspheres with controllable particle sizes. The preparation method comprises the following steps: step 1, preparing a silicon dioxide microsphere dispersion liquid by adopting a stber method; 2, centrifuging, washing and freeze-drying the silicon dioxide microsphere dispersion liquid to obtain submicron silicon dioxide seed microspheres; 3, a certain amount of ethyl alcohol is added into a round-bottom flask, a certain amount of silicon dioxide seed microspheres are taken and dispersed in the ethyl alcohol, dispersion liquid a is obtained and subjected to ultrasonic oscillation for 1 h, and then a certain amount of ammonia water and water are added to prepare dispersion liquid b; according to the preparation method, the particle size control can be realized, and the uniform micron-sized silicon dioxide microspheres can be efficiently and economically obtained, so that the requirements of the market on high-performance materials are met, and the influence of the production process on the environment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of silica nanospheres, and more specifically, to a silica nanosphere with controllable particle size and a preparation method thereof. Background Art

[0002] Silica (SiO2), as an important inorganic material, is widely used in the fields of electronics, coatings, plastics, medicine, etc. Its unique physical and chemical properties make uniform silica microspheres valuable in many high-performance applications. Different particle sizes of silica microspheres have different applications: Silica microspheres with a size of 150 - 500 nm can be used to prepare structural color materials by self-assembly; Submicron silica with a size of 400 - 700 nm can be used as chromatographic materials in the medical field; New groups can be grafted onto the surface of silica particles with a size of 500 - 1000 nm to endow them with hydrophilic, hydrophobic, thermosensitive, pH-responsive and other characteristics; Silica microspheres with a size of 1000 - 1500 nm can be modified to make polymers have better mechanical properties; Self-assembly of silica microspheres with a size of 2000 - 5000 nm can prepare photonic crystal infrared stealth materials.

[0003] Currently, the silica microspheres used are mainly prepared by chemical synthesis methods, and the synthesis methods mainly include reverse microemulsion method, precipitation method, sol-gel method, seed growth method, etc. These methods have their own advantages and disadvantages, but generally have the following problems:

[0004] Non-uniform particle size: Many existing methods are difficult to control the particle size and morphology of the generated microspheres, resulting in unstable product performance.

[0005] High production cost: The complex process flow and equipment requirements pose challenges to large-scale production.

[0006] Environmental impact: Some preparation processes may produce harmful by-products, causing pollution to the environment.

[0007] With the progress of technology, the demand for high-performance materials in various industries is increasing. Uniform micron-sized silica microspheres have gradually attracted attention due to their excellent fluidity, filling ability and surface modification ability. For example, in the coating and plastic industries, uniform micron-sized silica can significantly improve the strength and wear resistance of products. In addition, with the increasingly strict environmental protection regulations, the development of preparation processes with low environmental impact has also become an important direction for the industry to develop.

[0008] Therefore, there is an urgent need for a new preparation method that can efficiently and economically obtain uniform micron-sized silica microspheres to meet the market demand for high-performance materials and reduce the environmental impact during the production process. Summary of the Invention

[0009] To overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a silica nano-microsphere with controllable particle size and a preparation method thereof. The preparation of the silica nano-microsphere of the present invention can achieve the control of particle size, and can efficiently and economically obtain uniform micron-sized silica microspheres to meet the market demand for high-performance materials and reduce the impact of the production process on the environment, so as to solve the problems raised in the above-mentioned background technology.

[0010] To achieve the above object, the present invention provides the following technical solution: A silica nano-microsphere with controllable particle size, including a silica nano-microsphere body.

[0011] A preparation method of a silica nano-microsphere with controllable particle size, comprising the following steps:

[0012] Step 1: Use method to prepare a silica microsphere dispersion;

[0013] Step 2: Centrifuge, wash, and freeze-dry the silica microsphere dispersion to obtain sub-micron silica seed microspheres;

[0014] Step 3: Add a certain amount of ethanol to a round-bottom flask, take a certain amount of the silica seed microspheres and disperse them therein to obtain dispersion a, ultrasonically vibrate for 1 h, and then add a certain amount of ammonia water and water to prepare dispersion b;

[0015] Step 4: Place dispersion b in a magnetic stirrer at 30°C - 55°C. After 10 min, add tetraethyl orthosilicate accounting for 5% - 11% of the total volume of the solvent at a certain rate. Take a small amount of the reaction solution from the round-bottom flask every 5 - 30 min to test the particle size until the target particle size is produced, and terminate the reaction to obtain silica dispersion c;

[0016] Step 5: Centrifuge, wash, and freeze-dry silica dispersion c to obtain white micron-sized silica microspheres, and the microspheres are uniform in size and have a particle size of 1 - 4 μm.

[0017] In a preferred embodiment, the volume fractions of ethanol, ammonia water, and water in dispersion b in Step 3 are 78% - 90%, 7% - 16%, and 3% - 6% respectively, and the mass of silica accounts for 0.6% - 1.2% of the total mass of the solvent.

[0018] In a preferred embodiment, the particle size range of the sub-micron silica seed microspheres in Step 2 is 500 nm - 1000 nm.

[0019] In a preferred embodiment, in Step 1, use The specific steps for preparing the silica microsphere dispersion by the method are as follows: Ethanol, ammonia water, and water with mass fractions of 78%-90%, 16%-7%, and 6%-3% respectively are added to a round-bottom flask in sequence, placed in a magnetic stirrer at a temperature of 30°C - 55°C, stirred until the temperature is stable, and tetraethyl orthosilicate is added, followed by continued reaction for 2 hours. Among them, the total mass fraction of ethanol, ammonia water, and water is 100%, and the dosage of tetraethyl orthosilicate accounts for 11%-5% of the total volume of the solvent.

[0020] In a preferred embodiment, in the dispersion b in step three, the volumes of ethanol, ammonia water, and water are 40 ml, 8 ml, and 3 ml respectively, and the mass of silica is 0.618 g.

[0021] In a preferred embodiment, in step four, the dropping rate of tetraethyl orthosilicate is 12 ml / h.

[0022] In a preferred embodiment, in step four, the liquid taken out from the round-bottom flask at each time interval is 20 μl, which is dispersed in 1.5 ml of ethanol solution and then the particle size is measured.

[0023] In a preferred embodiment, the steps of centrifugation, washing, and freeze-drying in step two and step five are: centrifugation - water washing - centrifugation - ethanol washing - centrifugation - ethanol washing - centrifugation - freeze-drying.

[0024] In a preferred embodiment, the rotation speed of centrifugation in step five is 2500 rpm.

[0025] The technical effects and advantages of the present invention:

[0026] The present invention can control the particle size of the prepared silica nanospheres, efficiently and economically obtain uniform micron-sized silica microspheres to meet the market demand for high-performance materials, and reduce the environmental impact during the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the preparation process of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] As shown in the attached Figure 1As shown in the figure, the present invention provides a silica nano - microsphere with controllable particle size, including a silica nano - microsphere body.

[0030] A preparation method of a silica nano - microsphere with controllable particle size, comprising the following steps:

[0031] Step 1: Use method to prepare a silica microsphere dispersion;

[0032] Step 2: Centrifuge, wash, and freeze - dry the silica microsphere dispersion to obtain sub - micron silica seed microspheres;

[0033] Step 3: Add a certain amount of ethanol to a round - bottom flask, take a certain amount of the silica seed microspheres and disperse them therein to obtain dispersion a, ultrasonically vibrate for 1 h, and then add a certain amount of ammonia water and water to prepare dispersion b;

[0034] Step 4: Place dispersion b in a magnetic stirrer at 30 °C - 55 °C. After 10 min, add tetraethyl orthosilicate accounting for 5% - 11% of the total volume of the solvent at a certain rate. Take a small amount of the reaction solution from the round - bottom flask every 5 - 30 min to test the particle size until the target particle size is produced, and then terminate the reaction to obtain silica dispersion c;

[0035] Step 5: Centrifuge, wash, and freeze - dry silica dispersion c to obtain white micron - sized silica microspheres, and the microspheres are of uniform size with a particle size of 1 - 4 μm.

[0036] In dispersion b in Step 3, the volume fractions of ethanol, ammonia water, and water are 78% - 90%, 7% - 16%, and 3% - 6% respectively, and the mass of silica accounts for 0.6% - 1.2% of the total mass of the solvent.

[0037] The particle size range of the sub - micron silica seed microspheres in Step 2 is 500 nm - 1000 nm.

[0038] The specific steps of using method to prepare a silica microsphere dispersion in Step 1 are as follows: Add ethanol, ammonia water, and water with mass fractions of 78% - 90%, 16% - 7%, and 6% - 3% respectively to a round - bottom flask in sequence, place it in a magnetic stirrer at a temperature of 30 °C - 55 °C, stir until the temperature is stable, add tetraethyl orthosilicate, and continue the reaction for 2 h. Among them, the total mass fraction of ethanol, ammonia water, and water is 100%, and the dosage of tetraethyl orthosilicate accounts for 11% - 5% of the total volume of the solvent.

[0039] In dispersion b in Step 3, the volumes of ethanol, ammonia water, and water are 40 ml, 8 ml, and 3 ml respectively, and the mass of silica is 0.618 g.

[0040] In step 4, the dropping rate of tetraethyl orthosilicate is 12 ml / h.

[0041] In step 4, 20 μl of the liquid taken out from the round-bottom flask at each time interval is dispersed in 1.5 ml of ethanol solution and then the particle size is measured.

[0042] The steps of centrifugation, washing, and freeze-drying in step 2 and step 5 are: centrifugation - water washing - centrifugation - ethanol washing - centrifugation - ethanol washing - centrifugation - freeze-drying.

[0043] In step 5, the rotation speed of centrifugation is 2500 rpm.

[0044] Example 1

[0045] A method for preparing silica nanospheres with controllable particle size, comprising the following steps:

[0046] Step 1: Add 40 ml of ethanol, 8 ml of ammonia water, and 3 ml of water into a round-bottom flask in sequence. Place the round-bottom flask on a magnetic stirrer at a temperature of 30 °C and stir for 10 min. After the temperature is stable, add tetraethyl orthosilicate and react for another 2 h to obtain a silica microsphere dispersion;

[0047] Step 2: Subject the silica microsphere dispersion to centrifugation - water washing - centrifugation - ethanol washing - centrifugation - freeze-drying to obtain silica seed microspheres. Take 0.002 g of silica seed microspheres and disperse them in 1.5 ml of ethanol solution. The measured particle size is 600 nm and PDI = 0.03, indicating that the particle size of the seed microspheres is relatively uniform.

[0048] Step 3: Add 40 ml of ethanol into a round-bottom flask, and then disperse 0.618 g of silica seed microspheres in it to obtain dispersion a. Ultrasonically oscillate for 1 h, and then add 8 ml of ammonia water and 3 ml of water to prepare dispersion b;

[0049] Step 4: Place dispersion b on a magnetic stirrer at 30 °C and a rotation speed of 600 rpm. After 10 min, add tetraethyl orthosilicate at a rate of 12 ml / h. Take a certain amount of the reaction solution from the round-bottom flask every 5 min to measure the particle size until the particle size reaches 1450 nm. Stop adding tetraethyl orthosilicate and continue to react for 3 h to obtain a micron-sized silica dispersion c;

[0050] Step 5: Centrifuge, wash, and freeze-dry the silica dispersion c to obtain micron-sized silica powder. The size of the obtained silica powder microspheres is measured to be 1450 nm using a laser particle size analyzer; the polydispersity index (PDI) = 0.06, indicating that its molecular weight distribution is relatively uniform.

[0051] Example 2

[0052] A preparation method of silica nanospheres with controllable particle size, comprising the following steps:

[0053] Step 1: Add 40 ml of ethanol, 8 ml of ammonia water, and 3 ml of water into a round-bottom flask in sequence. Place the round-bottom flask on a magnetic stirrer at a temperature of 30 °C, stir for 10 min. After the temperature stabilizes, add tetraethyl orthosilicate, and then react fully for 2 h to obtain a silica microsphere dispersion;

[0054] Step 2: Subject the silica microsphere dispersion to centrifugation - water washing - centrifugation - ethanol washing - centrifugation - freeze-drying to obtain silica seed microspheres. Take 0.002 g of silica seed microspheres and disperse them in 1.5 ml of an ethanol solution. The measured particle size is 700 nm.

[0055] Step 3: Add 40 ml of ethanol into a round-bottom flask, and then disperse 0.618 g of silica seed microspheres in it to obtain dispersion a. Ultrasonically vibrate for 1 h, and then add 8 ml of ammonia water and 3 ml of water to prepare dispersion b;

[0056] Step 4: Place dispersion b on a magnetic stirrer at 30 °C and a rotation speed of 600 rpm. After 10 min, add tetraethyl orthosilicate at a rate of 12 ml / h. Take a certain amount of the reaction solution from the round-bottom flask every 5 min to test the particle size until the particle size reaches 1600 nm. Stop adding tetraethyl orthosilicate and continue to react for 3 h to obtain a micron-sized silica dispersion c;

[0057] Step 5: Centrifuge, wash, and freeze-dry the silica dispersion c to obtain micron-sized silica microspheres. Use a laser particle size analyzer to measure the size of the obtained silica powder microspheres as 1600 nm, PDI = 0.07; the obtained microspheres are uniform micron-sized silica microspheres.

[0058] Example 3

[0059] A preparation method of silica nanospheres with controllable particle size, comprising the following steps:

[0060] Step 1: Add 40 ml of ethanol, 8 ml of ammonia water, and 3 ml of water into a round-bottom flask in sequence. Place the round-bottom flask on a magnetic stirrer at a temperature of 30 °C, stir for 10 min. After the temperature stabilizes, add tetraethyl orthosilicate, and then react fully for 2 h to obtain a silica microsphere dispersion;

[0061] Step 2: Disperse the silica microsphere dispersion through centrifugation - water washing - centrifugation - ethanol washing - centrifugation - freeze drying to obtain silica seed microspheres. Take 0.002 g of silica seed microspheres and disperse them in 1.5 ml of ethanol solution. The measured particle size is 700 nm.

[0062] Step 3: Add 40 ml of ethanol to a round - bottom flask, and then disperse 0.618 g of silica seed microspheres in it to obtain dispersion a. Ultrasonically vibrate for 1 h, and then add 8 ml of ammonia water and 3 ml of water to prepare dispersion b.

[0063] Step 4: Place dispersion b on a magnetic stirrer at 30 °C with a rotation speed of 600 rmp. After 10 min, add tetraethyl orthosilicate at a rate of 12 ml / h. Take a certain amount of the reaction solution from the round - bottom flask every 5 min to measure the particle size until the particle size reaches 4000 nm. Stop adding tetraethyl orthosilicate and continue the reaction for 3 h to obtain a micron - sized silica dispersion c.

[0064] Step 5: Centrifuge, wash, and freeze - dry the silica dispersion c to obtain micron - sized silica powder. The size of the obtained silica microspheres measured by a laser particle size analyzer is 4000 nm, and PDI = 0.09.

[0065] The preparation of silica nanospheres in the present invention can achieve the control of particle size, and can efficiently and economically obtain uniform micron - sized silica microspheres to meet the market demand for high - performance materials and reduce the environmental impact during the production process.

[0066] Finally: The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A silica nanoparticle with controllable particle size, characterized in that: The invention comprises a silicon dioxide nano-microsphere body.

2. A method for preparing silica nanoparticles with controllable particle size, characterized in that: The following steps are involved: Step 1: Prepare silica microsphere dispersion by Stöber method; Step 2: centrifuging, washing, and freeze-drying the silica microsphere dispersion to obtain submicron silica seed microspheres; Step 3: Add a certain amount of ethanol to a round-bottom flask, take a certain amount of the silica seed microspheres and disperse them therein to obtain dispersion a, perform ultrasonic vibration for 1 hour, and then add a certain amount of ammonia water and water to prepare dispersion b; Step 4: placing the dispersion liquid b in a magnetic stirrer at 30° C.-55° C., adding 5%-11% of ethyl orthosilicate to the total volume of the solvent at a certain rate after 10 minutes, taking out a small amount of the reaction liquid from the round-bottom flask every 5-30 minutes to test the particle size until the target particle size is obtained, terminating the reaction, and obtaining a silicon dioxide dispersion liquid c; Step 5: Centrifuge, wash and freeze-dry the silica dispersion c to obtain white micron-sized silica microspheres, wherein the microspheres are uniform in size and have a particle size of 1-4 um.

3. The method for preparing a silica nanoparticle with controllable particle size according to claim 2, characterized in that: In the step 3, the volume fractions of ethanol, ammonia water and water in the dispersion b are 78%-90%, 7%-16% and 3%-6% respectively, accounting for 6%-2% of the total mass of the silica solvent.

4. The method for preparing a silica nanoparticle with controllable particle size according to claim 2, characterized in that: The particle size of the submicron silica seed microspheres in step 2 is in the range of 500nm-1000nm.

5. The method for preparing a silica nanoparticle with controllable particle size according to claim 2, characterized in that: The specific steps of preparing the silica microsphere dispersion by the Stöber method in step 1 are as follows: ethanol, ammonia water and water with mass fractions of 78%-90%, 16%-7% and 6%-3% are added to a round-bottom flask in order, placed in a magnetic stirrer at a temperature of 30°C-55°C, stirred until the temperature is stable, and tetraethyl orthosilicate is added, and the reaction is continued for 2 hours, wherein the total mass fraction of ethanol, ammonia water and water is 100%, and the amount of tetraethyl orthosilicate used accounts for 11%-5% of the total volume of the solvent.

6. The method for preparing silica nanoparticles with controllable particle size according to claim 2, characterized in that: In the step 3, the volumes of ethanol, ammonia water and water in the dispersion solution b are 40 ml, 8 ml and 3 ml respectively, and the mass of silicon dioxide is 618 g.

7. The method for preparing silica nanoparticles with controllable particle size according to claim 2, characterized in that: The dropping speed of ethyl orthosilicate in the step 4 is 12 ml / h.

8. The method for preparing silica nanoparticles with controllable particle size according to claim 2, characterized in that: In the step 4, 20 μl of liquid is taken out from the round-bottom flask at each time interval, dispersed in 5 ml of ethanol solution and then the particle size is tested.

9. The method for preparing silica nanoparticles with controllable particle size according to claim 2, characterized in that: The steps of centrifugation, washing and freeze drying in step 2 and step 5 are: centrifugation-water washing-centrifugation-ethanol washing-centrifugation-ethanol washing-centrifugation-freeze drying.

10. The method for preparing silica nanoparticles with controllable particle size according to claim 2, characterized in that: The centrifugal speed in step 5 is 2500 rpm.

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