Amorphous silicon dioxide microspheres with uniform size and preparation method thereof
By adding polyacrylamide and tetraethoxysilane to an aqueous solution of ethylene glycol at room temperature, micron-scale amorphous silica microspheres with uniform particle size were prepared, which solved the complex and costly preparation process in the prior art. The problem of high and poor stability has achieved high purity and applicability of microsphere preparation.
Patent Information
- Application Number
- CN202411555783.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-02-11
AI Technical Summary
It is difficult to effectively prepare micron-scale amorphous silica microspheres with uniform sizes, especially in the range of 1-5 μm, and there are problems such as complex process, high cost and poor stability during the preparation process.
A preparation method is adopted, which includes mixing ethylene glycol with deionized water at room temperature, adding polyacrylamide and then adding tetraethoxysilane dropwise, and after stirring, solid-liquid separation, washing, drying and heat treatment, finally Amorphous silica microspheres of uniform size were obtained.
The preparation of micron-scale silica microspheres with controllable particle size is achieved. The product has a relatively uniform particle size and high purity. It is suitable for drug carriers, bioadsorption, chromatographic fillers and other fields, broadening the application range of materials.
Smart Images
Figure CN119409203A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an inorganic microsphere and a preparation method thereof, in particular to an amorphous silicon dioxide microsphere with uniform size and a preparation method thereof. Background Art
[0002] Silica microspheres are a kind of inorganic non-metallic material with non-toxicity, good stability, excellent mechanical and electrical properties, especially monodisperse silica microspheres, which have potential application value in drug carriers, bioadsorption, chromatographic fillers, flat panel displays, cosmetics, etc. due to their uniform and controllable size, single composition and surface functionalization. Since Stobel et al. first synthesized monodisperse nano-silica microspheres in 1968, scientists have developed many preparation methods for silica spheres, and have obtained some applications in ceramic products, rubber modification, plastics, coatings, biological cell separation and medical engineering, sunscreens, pigments, etc.
[0003] There are many traditional methods for preparing silica microspheres, such as the Stober method, gas phase method, microemulsion method, precipitation method, sol-gel method and sol-seed method. Although the silica microspheres prepared by the gas phase method have high purity and good monodispersity, the process operation is complicated, the equipment requirements are high, the output is low, and the cost is high; although the microemulsion method can obtain microspheres with good dispersibility, the particle size of the synthesized microspheres is generally large, the size uniformity is average, and the solvent used in the preparation process is highly toxic, and the silicon source used is expensive; the precipitation method has a lower cost, but the microspheres obtained have poor dispersibility and a very low yield; the Stober method and the sol-gel method for preparing silica microspheres have the advantages of mild conditions, simple process equipment, simple operation, low cost, good monodispersity, and high purity, and are widely used. However, the silica microspheres prepared by these two methods have a small particle size, ranging from tens of nanometers to hundreds of nanometers, and are not suitable for preparing silica microspheres with larger particle sizes; although the sol-seed method can prepare silica microspheres with large particle size and good dispersibility, the control of its preparation conditions is difficult and it is difficult to ensure its stability. Nano-silica microspheres have great problems in practical applications due to their small size, difficulty in dispersion, size uniformity, etc., especially in the field of electronic information, such as optoelectronic display, communication substrates, etc. Therefore, the preparation technology and application of micron-sized silica microspheres with uniform size distribution deserve research and attention, especially the use of appropriate preparation technology to obtain amorphous silica microspheres with a size of 1-5 μm and uniform size. Summary of the invention
[0004] The purpose of the present invention is to solve the deficiencies of the prior art and provide a method for preparing amorphous silica microspheres with uniform size, which can obtain micron-sized silica spheres and provide technical support for broadening the application range of the material and its industrialization.
[0005] To achieve the above object, the present invention adopts the following technical solution:
[0006] A method for preparing amorphous silicon dioxide microspheres with uniform size comprises the following steps:
[0007] (1) adding ethylene glycol to deionized water at room temperature and stirring uniformly to obtain an ethylene glycol aqueous solution;
[0008] (2) adding polyacrylamide to the ethylene glycol aqueous solution obtained in step (1), stirring and mixing uniformly to obtain a premixed solution;
[0009] (3) adding tetraethoxysilane dropwise to the premixed solution obtained in step (2), stirring for reaction, separating the solid from the liquid, washing the solid product, and drying it to obtain a white powder;
[0010] (4) heat-treating the white powder obtained in step (3) and cooling the mixture after heat treatment.
[0011] Furthermore, in step (1), the mass ratio of ethylene glycol to deionized water is (21.28-34.05):(25.03-45.12).
[0012] Furthermore, in step (2), the mass ratio of the polyacrylamide to ethylene glycol is (0.58-0.86):(21.28-34.05).
[0013] Furthermore, in step (3), the mass ratio of tetraethoxysilane to ethylene glycol is (2.32-4.18):(21.28-34.05).
[0014] Furthermore, in step (4), the heat treatment method is: firstly heating the temperature to 600-700°C at a heating rate of 3°C / min, keeping the temperature for 4-6h, then heating the temperature to 1000-1100°C at a heating rate of 5°C / min, keeping the temperature for 2-4h.
[0015] The amorphous silica microspheres are prepared by the above method.
[0016] Compared with the prior art, the present invention has the following beneficial effects:
[0017] 1) The raw materials of the method of the present invention are simple, widely available, easy to obtain, low in cost and environmentally friendly, the process is simple and environmentally friendly, suitable for industrial production, and has wide applicability.
[0018] 2) The silica microspheres prepared by the method of the present invention have a particle size of about 1-5 μm, are relatively uniform in size and have high purity.
[0019] 3) The method of the present invention can be used to prepare silica microspheres with smooth surface and good dispersibility, which are not easy to agglomerate and have good fluidity, thereby improving the processing adaptability of the material.
[0020] 4) The present invention broadens the idea of preparing silica microspheres by liquid phase method. Silica microspheres with adjustable particle size can be obtained by using different premixed liquid systems. The prepared silica microspheres can be used in the fields of drug carriers, bioadsorption, chromatographic fillers, electronic information and communication technology, etc., thus broadening the preparation technology and application fields of the material. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a SEM image of the amorphous silica microspheres prepared in Example 1;
[0022] Figure 2 The XRD pattern of amorphous silica microspheres prepared in Example 1;
[0023] Figure 3 is a SEM image of amorphous silica microspheres prepared in Example 2;
[0024] Figure 4 This is a SEM image of the amorphous silica microspheres prepared in Example 3. DETAILED DESCRIPTION
[0025] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but is not intended to limit the present invention.
[0026] Example 1
[0027] A method for preparing amorphous silicon dioxide microspheres with uniform size comprises the following steps:
[0028] (1) At room temperature, ethylene glycol was added to deionized water in a mass ratio of ethylene glycol to water of 21.28:25.03, and stirred evenly to obtain a clear and transparent ethylene glycol aqueous solution;
[0029] (2) adding polyacrylamide to the ethylene glycol aqueous solution obtained in step (1), wherein the mass ratio of polyacrylamide to ethylene glycol is 0.58:21.28, and stirring and mixing uniformly to obtain a premixed solution;
[0030] (3) tetraethoxysilane was added dropwise to the premixed solution obtained in step (2), the mass ratio of tetraethoxysilane to ethylene glycol being 2.32:21.28, the mixture was stirred for reaction for 4.5 h and then centrifuged, the solid product was washed with deionized water, and then dried at 90° C. to obtain a white powder;
[0031] (4) The white powder obtained in step (3) is first heated to 600° C. at a heating rate of 3° C. / min, kept at this temperature for 5 h, then heated to 1000° C. at a heating rate of 5° C. / min, kept at this temperature for 3 h, and then cooled in the furnace to obtain amorphous silica microspheres of uniform size.
[0032] Figure 1 This is a SEM image of the amorphous silica microspheres prepared in Example 1. It can be seen that the prepared silica microspheres are uniform in size, and the size of the microspheres is about 1.2 μm.
[0033] Figure 2 This is the XRD pattern of the amorphous silica microspheres prepared in Example 1. It can be seen that the prepared silica microspheres are amorphous.
[0034] Example 2
[0035] A method for preparing amorphous silicon dioxide microspheres with uniform size comprises the following steps:
[0036] (1) adding ethylene glycol to deionized water at room temperature, wherein the mass ratio of ethylene glycol to water is 27.66:35.05, and stirring evenly to obtain a clear and transparent ethylene glycol aqueous solution;
[0037] (2) adding polyacrylamide to the ethylene glycol aqueous solution obtained in step (1), wherein the mass ratio of polyacrylamide to ethylene glycol is 0.71:27.66, and stirring and mixing uniformly to obtain a premixed solution;
[0038] (3) tetraethoxysilane was added dropwise to the premixed solution obtained in step (2), wherein the mass ratio of tetraethoxysilane to ethylene glycol was 3.25:27.66, and the mixture was stirred for 4.5 h and then centrifuged. The solid product was washed and dried to obtain a white powder;
[0039] (4) The white powder obtained in step (3) was first heated to 600° C. at a heating rate of 3° C. / min, kept at this temperature for 6 h, then heated to 1000° C. at a heating rate of 5° C. / min, kept at this temperature for 4 h, and then cooled in the furnace to obtain amorphous silica microspheres of uniform size.
[0040] Figure 3 This is a SEM image of the amorphous silica microspheres prepared in Example 2. It can be seen that the prepared silica microspheres are uniform in size, and the microsphere size is about 3.2 μm.
[0041] Example 3
[0042] A method for preparing amorphous silicon dioxide microspheres with uniform size comprises the following steps:
[0043] (1) At room temperature, ethylene glycol was added to deionized water in a mass ratio of 34.05:45.12, and stirred evenly to obtain a clear and transparent ethylene glycol aqueous solution;
[0044] (2) adding polyacrylamide to the ethylene glycol aqueous solution obtained in step (1), wherein the mass ratio of polyacrylamide to ethylene glycol is 0.86:34.05, and stirring and mixing uniformly to obtain a premixed solution;
[0045] (3) tetraethoxysilane was added dropwise to the premixed solution obtained in step (2), the mass ratio of tetraethoxysilane to ethylene glycol being 4.18:34.05, the mixture was stirred for reaction for 4.5 h and then centrifuged, the solid product was washed and dried to obtain a white powder;
[0046] (4) The white powder obtained in step (3) was first heated to 700° C. at a heating rate of 3° C. / min, kept at this temperature for 4 h, then heated to 1100° C. at a heating rate of 5° C. / min, kept at this temperature for 2 h, and then cooled in the furnace to obtain amorphous silica microspheres of uniform size.
[0047] Figure 4 This is a SEM image of the amorphous silica microspheres prepared in Example 3. It can be seen that the prepared silica microspheres are uniform in size, and the microsphere size is about 4.9 μm.
Claims
1. A method for preparing amorphous silica microspheres of uniform size, characterized in that: The steps include: (1) adding ethylene glycol to deionized water at room temperature and stirring uniformly to obtain an ethylene glycol aqueous solution; (2) adding polyacrylamide to the ethylene glycol aqueous solution obtained in step (1), stirring and mixing uniformly to obtain a premixed solution; (3) adding tetraethoxysilane dropwise to the premixed solution obtained in step (2), stirring for reaction, separating the solid from the liquid, washing the solid product, and drying it to obtain a white powder; (4) subjecting the white powder obtained in step (3) to heat treatment and then cooling to obtain the product.
2. The method for preparing amorphous silica microspheres of uniform size as claimed in claim 1, characterized in that: In step (1), the mass ratio of ethylene glycol to deionized water is (21.28-34.05):(25.03-45.12).
3. The method for preparing amorphous silica microspheres of uniform size as claimed in claim 1, characterized in that: In step (2), the mass ratio of the polyacrylamide to ethylene glycol is (0.58-0.86):(21.28-34.05).
4. The method for preparing amorphous silica microspheres of uniform size as claimed in claim 1, characterized in that: In step (3), the mass ratio of tetraethoxysilane to ethylene glycol is (2.32-4.18):(21.28-34.05).
5. The method for preparing amorphous silica microspheres of uniform size as claimed in claim 1, characterized in that: In step (4), the heat treatment method is: firstly heating the temperature to 600-700°C at a heating rate of 3°C / min, keeping the temperature for 4-6h, then heating the temperature to 1000-1100°C at a heating rate of 5°C / min, keeping the temperature for 2-4h.
6. Amorphous silica microspheres prepared by the method according to any one of claims 1 to 5.