Preparation method of silicon oxide nanoparticles with controllable morphology

Abstract

The invention provides a preparation method of morphology-controllable silicon oxide nanoparticles, which comprises the following steps: (1) preparing alkali liquor which contains organic amine or amino acid with buffering capacity and has the pH value of about 8-10.5; (2) preparing hydrolysate which contains deionized water, ethanol and tetraethoxysilane in a certain proportion and has a controllable siloxane hydrolysis state; (3) adding the hydrolysate into the alkali liquor prepared in the step (1) according to a small-amount multi-time method, and reacting for 1-5 hours to obtain a silicon oxide nano-particle solution; and (4) carrying out large particle filtration, solvent replacement and concentration on the silicon oxide nanoparticle solution by an ultrafiltration method to finally obtain the silicon oxide nanoparticle product with controllable morphology. The morphology of the synthesized high-purity silicon oxide nanoparticles can be accurately regulated and controlled according to actual requirements. Due to the characteristic, the silicon oxide nano-particles can fully meet the diversified requirements on abrasive morphology under different chemical mechanical polishing (CMP) scenes.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomaterial preparation, and particularly relates to a method for preparing silica nanoparticles with controllable morphology. Background Art

[0002] As a key nanomaterial, silica nanoparticles play a crucial role in the field of semiconductor chemical mechanical polishing (CMP). CMP is one of the core processes in semiconductor chip manufacturing. Its principle is to achieve planarization of the wafer surface through the synergistic action of chemical etching and mechanical grinding to meet the stringent requirements for the flatness between different material layers in chip manufacturing. In this process, silica nanoparticles, as the key abrasive component of the polishing liquid, directly affect the polishing effect and the manufacturing quality of the chip.

[0003] With the continuous development of semiconductor technology towards higher integration and smaller process dimensions, chip manufacturing processes pose unprecedented challenges to the accuracy, efficiency, and surface quality of the CMP process. For silica nanoparticles, their application in the CMP field faces many problems. In terms of purity, even trace amounts of metal impurities in silica nanoparticles, such as metal ions like sodium, potassium, and iron, may diffuse into the silicon wafer or electronic device during the CMP process, causing serious problems such as short circuits, resulting in a decline in chip performance or even scrapping. Therefore, the demand for ultra-high purity silica nanoparticles is becoming increasingly urgent.

[0004] In terms of the morphology of silica nanoparticles, different CMP stages have different requirements for the particle size and shape of silica nanoparticles. In the rough polishing stage, in order to achieve a higher removal rate, larger particle size abrasives are required; while in the fine polishing stage, more attention is paid to surface flatness, and smaller particle size abrasives are preferred. At the same time, non-spherical silica nanoparticles, such as peanut-shaped and irregular-shaped ones, have received extensive attention because they can increase the contact area between abrasive particles and the wafer, improve the friction force, and thus enhance the polishing rate. However, existing technologies face many difficulties in preparing silica nanoparticles with specific morphology and particle size distribution. Traditional preparation methods, such as ion exchange method, elemental silicon hydrolysis method, and sol-gel method, etc., are difficult to precisely control the morphology and particle size of silica nanoparticles.

[0005] Currently, CN102390838A discloses a method for preparing non-spherical silica nanoparticles, but it requires the preparation of seeds and the synthesis process flow is relatively complex. CN111498856B discloses a two-phase preparation method for high-purity silica nanoparticles, but its morphology control agent is expensive and the control of the two-phase process is complex. Existing methods for preparing silica nanoparticles have many deficiencies in controlling the morphology of silica nanoparticles and cannot meet the requirements of high-end application fields.

[0006] In summary, developing a preparation method of silicon oxide nanoparticles that can effectively solve the above problems is of great practical significance for promoting the progress of semiconductor CMP technology and meeting the growing chip manufacturing demands. Summary of the Invention

[0007] The object of the present invention is to provide a preparation method of silicon oxide nanoparticles with controllable morphology to solve the problem that the morphology of silicon oxide nanoparticles is difficult to control in the prior art. The silicon oxide nanoparticles prepared by this method have characteristics such as high compactness, controllable morphology, and stable performance, and have high industrial practical value. The specific technical solutions are as follows:

[0008] A preparation method of silicon oxide nanoparticles with controllable morphology, characterized by comprising the following steps:

[0009] (1) Prepare an alkaline solution: Select an alkaline organic substance with buffering ability, dissolve it in deionized water, and prepare an alkaline solution with a pH value between 8 and 10.5.

[0010] (2) Prepare a hydrolysis solution: Mix deionized water, ethanol, and tetraethoxysilane in proportion and stir evenly to prepare a hydrolysis solution.

[0011] (3) Prepare a silicon oxide nanoparticle solution: Add the hydrolysis solution prepared in step (2) to the alkaline solution prepared in step (1) at intervals in portions. After the addition is completed, continuously stir and react to obtain a silicon oxide nanoparticle solution.

[0012] (4) Filter and concentrate: First filter the silicon oxide nanoparticle solution in step (3) through a large-pore ultrafiltration membrane, then filter it through a small-pore ultrafiltration membrane. During this process, add ultrapure water for solvent replacement and concentration, and finally obtain silicon oxide nanoparticles with controllable morphology.

[0013] Further, the alkaline organic substance in step (1) includes any one or a combination of two of organic amines and amino acids; the organic amines include any one or several of ethylenediamine, butanediamine, dipropanolamine, and ammonia water; the amino acids include any one of arginine and lysine.

[0014] Further, the addition amount of the alkaline organic substance in step (1) is 1-5% of the mass of the alkaline solution, preferably 2-3%. Further, in step (2), the mass ratio of deionized water, ethanol, and tetraethoxysilane is (0-20):(50-70):(10-50), preferably (10-20):(50-60):(30-40).

[0015] Further, the stirring temperature in step (2) is 10-40°C, preferably 10-20°C; the stirring time is 1-3 h, preferably 1-2 h; and the stirring speed is 400-600 rpm.

[0016] Furthermore, the number of times of adding the hydrolysis solution in step (3) is 2 to 6 times, preferably 3 to 5 times; the interval time between each addition is 10 to 40 min, preferably 20 to 30 min; the reaction temperature is 20 to 60 °C, preferably 20 to 40 °C; stirring is maintained during the feeding and continuous reaction process, the stirring speed is 500 to 600 rpm, and the continuous reaction time is 1 to 2 h.

[0017] Furthermore, in step (4), the pore size of the large-pore ultrafiltration membrane is 0.5 to 5 μm, preferably 0.5 to 1 μm; the pore size of the small-pore ultrafiltration membrane is 0.005 to 0.05 μm, preferably 0.005 to 0.01 μm.

[0018] Furthermore, the concentration in step (4) is to concentrate the silicon oxide nanoparticle solution to a solid content of 20 to 40 wt%.

[0019] Beneficial effects:

[0020] 1. The inventors of the present invention found in actual work and research that the morphology of silicon oxide nanoparticles is mainly related to the hydrolysis rate of the silicon source and the adsorptive additives in the reaction solution. Therefore, the present invention can effectively control the hydrolysis rate of the silicon source by controlling the ratio of deionized water, ethanol, and tetraethoxysilane in the hydrolysis solution. And in the reaction process of the present invention, by adding long-chain organic amines and amino acids, the organic amines and amino acids can be adsorbed on the surface of the silicon source during the reaction process, thereby controlling the polymerization process of the silicon source. Through the above two steps, the growth process of silicon oxide nanoparticles can be controlled, thereby realizing the control of the morphology.

[0021] 2. In the present invention, an organic amine and amino acid system is used in the reaction, so that the overall reaction system has a certain buffering effect, and there is no need to use other alkaline substances to adjust the pH during the reaction process, which simplifies the experimental steps. At the same time, compared with the preparation and concentration by heating and evaporation in the preparation of other silicon oxide nanoparticles, the present invention realizes solvent replacement and filtration concentration by ultrafiltration method, reducing energy consumption. Description of the drawings

[0022] Figure 1 It is the TEM image of the silicon oxide nanoparticles in Example 1 of the present invention;

[0023] Figure 2 It is the TEM image of the silicon oxide nanoparticles in Example 2 of the present invention;

[0024] Figure 3 It is the TEM image of the silicon oxide nanoparticles in Example 4 of the present invention. Specific embodiments

[0025] The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0026] Example 1

[0027] This example provides a method for preparing silica nanoparticles with controllable morphology, including the following steps:

[0028] (1) Prepare an alkaline solution: Select an alkaline organic compound with buffering ability, dissolve it in deionized water, and prepare an alkaline solution with a pH value between 8 and 10.5;

[0029] Specifically, select butanediamine as the buffering reagent, weigh 12 g of butanediamine, add it to 488 g of deionized water, stir evenly to obtain an alkaline solution, and the pH of the alkaline solution is 10.

[0030] (2) Prepare a hydrolysis solution: Mix deionized water, ethanol, and tetraethoxysilane in proportion, and stir evenly to prepare a hydrolysis solution;

[0031] Specifically, mix 60 g of deionized water, 150 g of ethanol, and 90 g of tetraethoxysilane, stir and mix at 10 °C and 500 rpm for 1 h, and obtain a hydrolysis solution after mixing evenly.

[0032] (3) Prepare a silica nanoparticle solution: Add the hydrolysis solution prepared in step (2) to the alkaline solution prepared in step (1) at intervals in portions, and continue to stir and react after the addition is completed to obtain a silica nanoparticle solution;

[0033] Specifically, add the hydrolysis solution to the above alkaline solution in 5 portions, with an interval of 20 min between each addition, and continue to react for 2 h after the addition is completed. Control the temperature at 30 °C and the stirring speed at 500 rpm during the addition and reaction, and the pH of the reaction solution is 10. After the reaction is completed, a silica nanoparticle solution is obtained.

[0034] (4) Filter and concentrate: First filter the silica nanoparticle solution in step (3) through a large-pore ultrafiltration membrane, then filter it through a small-pore ultrafiltration membrane, add ultrapure water during the process for solvent replacement and concentration, and finally obtain silica nanoparticles with controllable morphology.

[0035] Specifically, perform ultrafiltration treatment on the silica nanoparticle solution. First select an ultrafiltration membrane with a pore size of 0.5 μm to filter and remove large particle impurities; then replace it with a 0.02-μm ultrafiltration membrane, add ultrapure water multiple times for solvent replacement, and at the same time perform concentration until the solid content of the silica nanoparticle solution reaches 30 wt%, to obtain silica nanoparticles. The prepared silica nanoparticles are basically as shown in the appendix Figure 1 as shown.

[0036] Example 2

[0037] This embodiment provides a method for preparing silica nanoparticles with controllable morphology, comprising the following steps:

[0038] (1) Prepare an alkaline solution: Select an alkaline organic compound with buffering capacity, dissolve it in deionized water, and prepare an alkaline solution with a pH value between 8 and 10.5;

[0039] Specifically, select butanediamine and dipropanolamine as buffering reagents, weigh 5 g of butanediamine and 10 g of dipropanolamine, add them to 485 g of deionized water, and stir evenly to obtain an alkaline solution with a pH of 9.5.

[0040] (2) Prepare a hydrolysis solution: Mix deionized water, ethanol, and tetraethoxysilane in proportion and stir evenly to prepare a hydrolysis solution;

[0041] Specifically, mix 30 g of deionized water, 180 g of ethanol, and 90 g of tetraethoxysilane at 15 °C with stirring at 500 rpm for 1 h, and stir evenly to obtain a hydrolysis solution.

[0042] (3) Prepare a silica nanoparticle solution: Add the hydrolysis solution prepared in step (2) to the alkaline solution prepared in step (1) at intervals in portions, and continue stirring and reacting after the addition is completed to obtain a silica nanoparticle solution;

[0043] Specifically, add the hydrolysis solution to the above alkaline solution in 4 portions, with an interval of 20 min between each addition, and continue reacting for 2 h after the addition is completed. Control the temperature at 30 °C and the stirring speed at 500 rpm during the addition and reaction, and the pH of the reaction solution is 9.5. After the reaction is completed, a silica nanoparticle solution is obtained.

[0044] (4) Filter and concentrate: First filter the silica nanoparticle solution in step (3) through a large-pore ultrafiltration membrane, then filter it through a small-pore ultrafiltration membrane, and add ultrapure water during this period for solvent replacement and concentration, finally obtaining silica nanoparticles with controllable morphology.

[0045] Specifically, perform ultrafiltration treatment on the silica nanoparticle solution. First select an ultrafiltration membrane with a pore size of 0.5 μm to filter out large particle impurities; then replace it with a 0.02 μm ultrafiltration membrane, add ultrapure water multiple times for solvent replacement, and at the same time perform concentration until the solid content of the silica nanoparticle solution reaches 30 wt%, obtaining silica nanoparticles. The prepared silica nanoparticles are basically as shown in the appendix Figure 2 as shown.

[0046] Example 3

[0047] This embodiment provides a method for preparing silica nanoparticles with controllable morphology, comprising the following steps:

[0048] (1) Prepare the alkaline solution: Select an alkaline organic compound with buffering capacity, dissolve it in deionized water, and prepare an alkaline solution with a pH value between 8 and 10.5;

[0049] Specifically, select lysine and butanediamine as buffering reagents, weigh 8 g of lysine and 6 g of butanediamine, add them to 486 g of deionized water, and stir evenly to obtain an alkaline solution with a pH of 9.8.

[0050] (2) Prepare the hydrolysis solution: Mix deionized water, ethanol, and tetraethoxysilane in proportion and stir evenly to prepare a hydrolysis solution;

[0051] Specifically, mix 50 g of deionized water, 150 g of ethanol, and 100 g of tetraethoxysilane at 15 °C with a stirring speed of 500 rpm for 1 h, and stir evenly to obtain a hydrolysis solution.

[0052] (3) Prepare the silicon oxide nanoparticle solution: Add the hydrolysis solution prepared in step (2) to the alkaline solution prepared in step (1) at intervals in portions, and continuously stir and react after the addition is completed to obtain a silicon oxide nanoparticle solution;

[0053] Specifically, add the hydrolysis solution to the above alkaline solution in 4 portions, with an interval of 30 min between each addition, and continue to react for 2 h after the addition is completed. Control the temperature at 30 °C and the stirring speed at 500 rpm during the addition and reaction, and the pH of the reaction solution is 9.8. After the reaction is completed, a silicon oxide nanoparticle solution is obtained.

[0054] (4) Filtration and concentration: First filter the silicon oxide nanoparticle solution in step (3) through a large-pore ultrafiltration membrane, and then filter it through a small-pore ultrafiltration membrane. During this process, add ultrapure water for solvent replacement and concentration, and finally obtain silicon oxide nanoparticles with controllable morphology.

[0055] Specifically, perform ultrafiltration treatment on the silicon oxide nanoparticle solution. First select an ultrafiltration membrane with a pore size of 0.5 μm to filter out large particle impurities; then replace it with a 0.02-μm ultrafiltration membrane, add ultrapure water multiple times for solvent replacement, and at the same time perform concentration until the solid content of the silicon oxide nanoparticle solution reaches 30 wt%, obtaining silicon oxide nanoparticles.

[0056] Example 4

[0057] This example provides a method for preparing silicon oxide nanoparticles with controllable morphology, including the following steps:

[0058] (1) Prepare the alkaline solution: Select an alkaline organic compound with buffering capacity, dissolve it in deionized water, and prepare an alkaline solution with a pH value between 8 and 10.5;

[0059] Specifically, lysine was selected as the buffer reagent. 15 g of lysine was weighed and added to 485 g of deionized water. After stirring evenly, an alkaline solution was obtained with a pH of 9.3.

[0060] (2) Preparation of the hydrolysis solution: Deionized water, ethanol, and tetraethoxysilane were mixed in proportion and stirred evenly to prepare the hydrolysis solution.

[0061] Specifically, 30 g of deionized water, 160 g of ethanol, and 110 g of tetraethoxysilane were stirred and mixed at 500 rpm at 20 °C for 1 h. After mixing evenly, the hydrolysis solution was obtained.

[0062] (3) Preparation of the silica nanoparticle solution: The hydrolysis solution prepared in step (2) was added to the alkaline solution prepared in step (1) at intervals in portions. After the feeding was completed, continuous stirring reaction was carried out to obtain the silica nanoparticle solution.

[0063] Specifically, the hydrolysis solution was added to the above alkaline solution in 5 portions, with an interval of 30 min between each feeding. After the feeding was completed, the reaction continued for 2 h. During the feeding and reaction process, the temperature was controlled at 25 °C, the stirring speed was 500 rpm, and the pH of the reaction solution was 9.3. After the reaction was completed, the silica nanoparticle solution was obtained.

[0064] (4) Filtration and concentration: The silica nanoparticle solution in step (3) was first filtered through a large-pore ultrafiltration membrane and then through a small-pore ultrafiltration membrane. During this period, ultrapure water was added for solvent replacement and concentration, and finally, silica nanoparticles with controllable morphology were obtained.

[0065] Specifically, ultrafiltration treatment was carried out on the silica nanoparticle solution. First, an ultrafiltration membrane with a pore size of 0.5 μm was selected to filter and remove large particle impurities; then, the ultrafiltration membrane was replaced with a 0.02-μm one, and ultrapure water was added multiple times for solvent replacement while concentrating until the solid content of the silica nanoparticle solution reached 30 wt%, obtaining the silica nanoparticles. The prepared silica nanoparticles are basically as shown in the appendix Figure 3 shown.

[0066] Example 5

[0067] The difference between this example and Example 4 is that arginine was used to replace lysine as the buffer reagent, and the addition amount was the same. The pH during the reaction process of the alkaline solution and the hydrolysis solution was 10.3, and the other steps and parameters were the same.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 1 is that more putrescine was added during the preparation of the alkaline solution, specifically 30 g of putrescine and 480 g of deionized water. The other steps were the same, and the pH during the reaction process of the alkaline solution and the hydrolysis solution was 11.5. The other steps and parameters were the same as those in Example 1.

[0070] Comparative Example 2

[0071] The difference between this comparative example and Example 2 is that the proportion of deionized water increases during the preparation of the hydrolysis solution. Specifically, it is 100 g of deionized water, 110 g of ethanol, and 90 g of tetraethoxysilane. The pH during the reaction of the alkali solution and the hydrolysis solution is 9.4, and other preparation steps and parameters are the same as those in Example 2.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 3 is that in the step of reacting to form the silicon oxide nanoparticle solution, the reaction temperature of the hydrolysis solution and the alkali solution is controlled at 40 °C, and the reaction time is 1 h. The pH during the reaction of the alkali solution and the hydrolysis solution is 9.7. Other steps and parameters are the same as those in Example 3.

[0074] Comparative Example 4

[0075] This comparative example provides a method for preparing silicon oxide nanoparticles with controllable morphology, including the following steps:

[0076] (1) Prepare the alkali solution: Select an alkaline organic substance with buffering ability, dissolve it in deionized water, and prepare an alkali solution with a pH value between 8 and 10.5;

[0077] Specifically, select ethylenediamine and ammonia water as buffering reagents, weigh 5 g of ethylenediamine and 10 g of ammonia water, add them to 485 g of deionized water, and stir evenly to obtain the alkali solution with a pH of 9.3.

[0078] (2) Prepare the hydrolysis solution: Mix deionized water, ethanol, and tetraethoxysilane in proportion, and stir evenly to prepare the hydrolysis solution;

[0079] Specifically, mix 150 g of deionized water, 100 g of ethanol, and 50 g of tetraethoxysilane at 30 °C and 500 rpm for 1 h, and stir evenly to obtain the hydrolysis solution.

[0080] (3) Prepare the silicon oxide nanoparticle solution: Add the hydrolysis solution directly to the above alkali solution at one time, and react for 3 h after the addition is completed. Control the temperature at 30 °C and the stirring speed at 500 rpm during the addition and reaction, and the pH of the reaction solution is 11. After the reaction is completed, obtain the silicon oxide nanoparticle solution.

[0081] (4) Filter and concentrate: First filter the silicon oxide nanoparticle solution in step (3) through a large-pore ultrafiltration membrane, then filter it through a small-pore ultrafiltration membrane, and add ultrapure water during this period for solvent replacement and concentration, and finally obtain silicon oxide nanoparticles with controllable morphology.

[0082] Specifically, the silica nanoparticle solution is ultrafiltered. First, an ultrafiltration membrane with a pore size of 0.5 μm is selected to filter out large particle impurities; then, the ultrafiltration membrane is replaced with a 0.02 μm one, and ultrapure water is added multiple times for solvent replacement while concentrating until the solid content of the silica nanoparticle solution reaches 30 wt%, obtaining silica nanoparticles.

[0083] The morphologies of the silica nanoparticles prepared in the above examples and comparative examples are detected. The detection results are shown in Table 1 and the attached drawings below. The detection method for the primary particle size is as follows: the specific surface area S is obtained by the BET specific surface area test method BET , and then the formula d = 2727 / S BE is used for calculation. The secondary particle size is measured by a Malvern particle size analyzer Zetasizer Lab. The degree of association is the ratio of the secondary particle size to the primary particle size. The gold impurity concentration is measured by an Agilent ICP-MS7700S.

[0084] Table 1 Statistical table of test results of silica nanoparticle parameters in examples and comparative examples

[0085]

[0086]

[0087] In the present invention, silica nanoparticles with different particle sizes and degrees of association are obtained by adjusting different components of raw materials and the process in the production process. By comparing Examples 1, 2, 3, 4, 5 with Comparative Example 4, it can be seen that the organic amines and amino acids used in the present invention can effectively control the morphology of silica nanoparticles and obtain different degrees of association. Long-chain organic amines or amino acids can adsorb on the surface of silica nanoparticles to adjust the charge state on the particle surface, thereby affecting their polymerization growth.

[0088] By comparing Example 1 with Comparative Example 1, it can be seen that the increase in organic amines promotes the nucleation process, thereby reducing the particle size and degree of association of silica nanoparticles. The size of the degree of association is related to the morphological size of the particles. The larger the degree of association, the more deviated the shape is from a sphere. Different degrees of association reflect the differences in the actual morphology. The prepared nano-silica in the present invention has a wide range of degrees of association, and actually, nano-silica with multiple sizes and morphologies can be prepared to meet the different requirements for the particle size and shape of silica nanoparticles in different CMP stages.

[0089] By comparing Example 2 with Comparative Example 2, it can be seen that the increase in the proportion of deionized water will cause more hydrolysis of the silicon source, thereby reducing the degree of association of silica nanoparticles.

[0090] By comparing Example 3 with Comparative Example 3, it can be seen that increasing the temperature can increase the polycondensation rate of silica nanoparticles, complete the growth of silica nanoparticles in a shorter time, and the degree of association is also higher.

[0091] Moreover, in the silica nanoparticle solution prepared by the method of the present application, the gold impurity content can be less than 1 ppm. Compared with the gold impurity content in the silica sol prepared by the ion exchange method, which is in the dozens or hundreds of ppm, and even some metal contents exceed 10,000 ppm, the silica nanoparticles prepared by the present invention have higher purity and can meet higher-end requirements.

[0092] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. In addition, it should be understood that although this specification is described according to the embodiments, it does not only include one technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing silica nanoparticles with controllable morphology, characterized in that, It includes the following steps: (1) Prepare an alkaline solution: Select an alkaline organic compound with buffering capacity, dissolve it in deionized water, and prepare an alkaline solution with a pH value between 8 and 10.5; (2) Prepare a hydrolysis solution: Mix deionized water, ethanol, and tetraethoxysilane in proportion, and stir evenly to prepare a hydrolysis solution; (3) Prepare a silicon oxide nanoparticle solution: Add the hydrolysis solution prepared in step (2) to the alkaline solution prepared in step (1) at intervals in portions. After the addition is completed, continuously stir and react to obtain a silicon oxide nanoparticle solution; (4) Filter and concentrate: First filter the silicon oxide nanoparticle solution in step (3) through a large-pore ultrafiltration membrane, and then filter it through a small-pore ultrafiltration membrane. During this process, add ultrapure water for solvent replacement and concentration to finally obtain silicon oxide nanoparticles with controllable morphology.

2. The preparation method of the silica nanoparticles with controllable morphology according to claim 1, wherein, The alkaline organic compound described in step (1) includes any one or a combination of two of organic amines and amino acids; the organic amines include any one or several of ethylenediamine, butanediamine, dipropanolamine, and ammonia water; the amino acids include any one of arginine and lysine.

3. The preparation method of the silica nanoparticles with controllable morphology according to claim 2, characterized in that, The addition amount of the alkaline organic compound in step (1) is 1-5% of the mass of the alkaline solution.

4. The preparation method of a silica nanoparticle with controllable morphology according to claim 1, characterized in that, In step (2), the mass ratio of deionized water, ethanol, and tetraethoxysilane is (0-20):(50-70):(10-50).

5. The preparation method of a silica nanoparticle with controllable morphology according to claim 4, characterized in that, In step (2), the stirring temperature is 10-40 °C; the stirring time is 1-3 h; the stirring speed is 400-600 rpm.

6. The preparation method of a silica nanoparticle with controllable morphology according to claim 1, characterized in that, In step (3), the addition times of the hydrolysis solution are 2-6 times, the interval time between each addition is 10-40 min, the reaction temperature is 20-60 °C, stirring is maintained during the addition and continuous reaction process, the stirring speed is 500-600 rpm, and the continuous reaction time is 1-2 h.

7. The preparation method of the silica nanoparticles with controllable morphology according to claim 1, characterized in that, In step (4), the pore size of the large-pore ultrafiltration membrane is 0.5-5 μm, and the pore size of the small-pore ultrafiltration membrane is 0.005-0.05 μm.

8. The preparation method of a silica nanoparticle with controllable morphology according to claim 1, wherein, In step (4), the concentration means concentrating the silicon oxide nanoparticle solution to a solid content of 20-40 wt%.

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