Preparation method for high silicification of surfaces of glass beads

Abstract

The invention relates to a preparation method of glass beads with high silicification on surfaces, which is characterized by comprising the following steps: (1) washing the glass beads with a sodium hydroxide solution and deionized water in sequence to obtain pretreated glass beads; (2) mixing a modifier with deionized water, uniformly stirring to obtain a mixed solution, adding the pretreated glass beads into the mixed solution, and stirring for 2-3 hours to obtain modified glass beads; and (3) adding the modified glass beads into deionized water, continuously adding a sodium hydroxide solution and a tetraethoxysilane solution, uniformly stirring for reaction, separating the glass beads from the solution after the reaction is finished, and drying in a drying oven to obtain the high silicification glass beads with uniformly coated and compact surfaces. The method has the advantages that the process is simple, the coating process is stable, the reaction time is short, the energy consumption is low, the preparation process is environment-friendly, and the coating process is suitable for various glass bead specifications; and the prepared silicon dioxide film layer is uniform and strong in adhesive force, and the binding property of the glass beads and a matrix material is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of functional material preparation, and relates to a method for preparing glass microbeads with high surface silicification. Background Art

[0002] Glass microspheres are micron-sized spherical materials with excellent chemical stability and mechanical strength. They are widely used in coatings, plastics, rubber, building materials, aerospace materials, and other fields. However, existing glass microspheres have certain surface performance limitations when used in certain specialized applications. For example, in harsh environments such as high temperatures, strong acids, and strong bases, the surface of glass microspheres is susceptible to corrosion or wear, resulting in a decrease in structural strength and limiting their use in demanding applications.

[0003] Currently, the treatment method mostly involves functional coating treatment on the surface of glass microbeads. Common surface coatings include oxide coatings, metallized coatings, etc. High siliconization treatment, as an effective surface modification method, can give glass microbeads higher corrosion resistance and stability by increasing the silicon content on the surface. After high siliconization treatment, a layer of chemically stable silicon oxide film is formed on the surface of the glass microbeads, which enables them to exhibit excellent corrosion resistance in high temperature, strong acid and strong alkali environments. In addition, glass microbeads that have undergone high siliconization treatment also have long-term antibacterial capabilities. They can also adsorb nucleic acid molecules, thereby completing the separation and purification process of proteins and nucleic acids, and can be widely used in medicine.

[0004] Despite this, existing hypersiliconization methods still face several challenges, such as strict temperature control requirements during the preparation process, long processing times, and high costs, which limit the industrial application of this technology. Patent publication number CN101864215A reportedly introduces silica via ethyl orthosilicate to coat hollow glass microspheres with silica. This method involves an acidic solution of nitric acid and pentanediol. The acidic conditions place high demands on the corrosion resistance of the equipment, and the treatment of the acidic wastewater also poses certain environmental challenges. Summary of the Invention

[0005] The purpose of the present invention is to make up for the shortcomings of the existing technology and provide a preparation method for glass microspheres with high surface silicification. The present invention optimizes the reaction conditions and process flow so that silicon dioxide can be evenly and firmly coated on the surface of the glass microspheres, thereby improving the chemical stability of the glass microspheres and expanding the application field of the glass microspheres.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for preparing glass microspheres with high surface silicification, characterized by comprising the following steps: (1) Glass microbeads with a particle size of 10-100 μm are added to a sodium hydroxide solution for alkaline washing, and then washed with deionized water (2-3 times) to obtain pretreated glass microbeads; (2) Mixing the modifier with deionized water at a mass ratio of 400-600:1-3 to the modifier, stirring evenly to obtain a mixed solution, and then mixing the mixed solution with the glass microbeads obtained in step (1) at a mass ratio of 1-5:10-100, stirring for 2-3 hours to obtain modified glass microbeads; (3) Add the modified glass microspheres to deionized water at a mass ratio of 1-3:200-400, and then add sodium hydroxide solution and ethyl orthosilicate solution (ethyl orthosilicate and anhydrous ethanol at a mass ratio of 1:1-3) to the water, and control the mass ratio of sodium hydroxide solution to glass to be 10-5:1, and the mass ratio of ethyl orthosilicate solution to glass to be 0.1-1:1-10; stir evenly and react for 100-600 minutes. After the reaction is completed, separate the glass microspheres from the solution and then place them in an oven (60-80°C) for drying to finally obtain highly silicated glass microspheres with a uniform and dense surface coating.

[0007] Furthermore, the modifier is at least one of γ-aminopropyltriethoxysilane, γ-propyltrimethoxysilane, and γ-methacryloyloxypropyl.

[0008] Compared with the prior art, the present invention has the following effects: (1) The present invention uses tetraethyl orthosilicate (TEOS) as a silicon source and coats the surface of glass microspheres with silicon dioxide by a sol-gel method. The process is simple, the coating process is stable, the reaction time is short, the energy consumption is low, and the coating process is applicable to a variety of glass microsphere specifications and has a wide range of applications. The preparation process is environmentally friendly and reduces the difficulty of treating acidic waste liquid. (2) The silicon dioxide film layer prepared by the present invention is uniform and has strong adhesion, which significantly improves the bonding between the glass microspheres and the matrix material. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is the surface morphology of the original glass microbead powder; Figure 2 This is the surface morphology of the highly silicated glass microbeads obtained in Example 1; Figure 3 This is the surface morphology of the highly silicated glass microbeads obtained in Example 2; Figure 4 This is the surface morphology of the highly silicated glass microbeads obtained in Example 3; Figure 5 This is the surface morphology of the highly silicated glass microbeads obtained in Example 4; Figure 6This is the surface morphology of the highly silicated glass microbeads obtained in Comparative Example 1; Figure 7 This is the surface morphology of the highly silicated glass microbeads obtained in Comparative Example 2.

[0010] It can be seen from the above morphology diagrams that the surfaces of the samples prepared in Comparative Examples 1 and 2 are flaky, while the surfaces of the samples prepared in Examples 1-4 are smoother and more evenly coated. DETAILED DESCRIPTION

[0011] A method for preparing a glass microsphere with high surface silicification, the specific implementation steps are as follows: Example 1

[0012] S1. Take 10 g of glass microspheres with a particle size of 10-100 μm, soak them in 10 wt% NaOH and ultrasonicate for 30 min, then rinse them twice with deionized water to obtain pretreated glass microspheres; S2. Take 0.1 g of the modifier (γ-aminopropyltriethoxysilane) and pre-mix it with 300 ml of deionized water, add the pre-treated glass microspheres and stir for 2 hours to obtain modified glass microspheres; S3. Add NaOH solution to the modified glass microspheres until the pH is 12, take 10 ml of ethyl orthosilicate and disperse it in 20 g of alcohol, slowly add it to the glass microspheres, and then stir at 80°C for 6 hours. After the reaction is completed, separate the glass microspheres by centrifugation, and then place them in an oven at 60°C and dry them for 360 minutes to finally obtain highly silicated glass microspheres with uniform and dense surface coating. Example 2

[0013] This embodiment provides a method for preparing glass microspheres with high surface silicification, comprising the following steps: S1. Take 10 g of glass microspheres with a particle size of 10-100 μm, soak them in 10 wt% NaOH and ultrasonicate for 30 min, then rinse them twice with deionized water to obtain pretreated glass microspheres; S2. Take 0.1 g of the modifier (γ-aminopropyltriethoxysilane) and pre-mix it with 300 ml of deionized water, add the pre-treated glass microspheres and stir for 2 hours to obtain modified glass microspheres; S3. Add NaOH solution to the modified glass microspheres until the pH is 12, take 20 ml of ethyl orthosilicate and disperse it in 20 g of alcohol, slowly add it to the glass microspheres, and then stir at 80°C for 6 hours. After the reaction is completed, separate the glass microspheres by centrifugation, and then place them in an oven at 60°C and dry them for 360 minutes to finally obtain highly silicated glass microspheres with uniform and dense surface coating. Example 3

[0014] This embodiment provides a method for preparing glass microspheres with high surface silicification, comprising the following steps: S1. Take 10 g of glass microspheres with a particle size of 10-100 μm, soak them in 10 wt% NaOH and ultrasonicate for 30 min, then rinse them twice with deionized water to obtain pretreated glass microspheres; S2. Take 0.1 g of the modifier (γ-aminopropyltriethoxysilane) and pre-mix it with 300 ml of deionized water, add the pre-treated glass microspheres and stir for 2 hours to obtain modified glass microspheres; S3. Add NaOH solution to the modified glass microspheres until the pH is 12, take 10 ml of ethyl orthosilicate and disperse it in 20 g of alcohol, slowly add it to the glass microspheres, and then stir at 80°C for 3 hours. After the reaction is completed, separate the glass microspheres by centrifugation, and then place them in an oven at 60°C and dry them for 360 minutes to finally obtain highly silicated glass microspheres with uniform and dense surface coating. Example 4

[0015] This embodiment provides a method for preparing glass microspheres with high surface silicification, comprising the following steps: S1. Take 10 g of glass microspheres with a particle size of 10-100 μm, soak them in 10 wt% NaOH and ultrasonicate for 30 min, then rinse them twice with deionized water to obtain pretreated glass microspheres; S2. Take 0.1 g of the modifier (γ-aminopropyltriethoxysilane) and pre-mix it with 300 ml of deionized water, add the pre-treated glass microspheres and stir for 2 hours to obtain modified glass microspheres; S3. Add NaOH solution to the modified glass microspheres until the pH is 12, take 10 ml of ethyl orthosilicate and disperse it in 20 g of alcohol, slowly add it to the glass microspheres, and then stir at 40°C for 6 hours. After the reaction is completed, separate the glass microspheres by centrifugation, and then place them in an oven at 60°C and dry them for 360 minutes to finally obtain highly silicated glass microspheres with uniform and dense surface coating.

[0016] This comparative example provides a method for preparing glass microspheres with high surface silicification, comprising the following steps: S1. Take 0.1 g of the modifier (γ-aminopropyltriethoxysilane) and pre-mix it with 300 ml of deionized water, add 10 g of glass microspheres and stir for 2 h to obtain modified glass microspheres; S2. Add NaOH solution to the modified glass microspheres until the pH is 12, take 10 ml of ethyl orthosilicate and disperse it in 20 g of alcohol, slowly add it to the glass microspheres, and then stir at 80°C for 6 hours. After the reaction is completed, separate the glass microspheres by centrifugation, and then place them in an oven at 60°C and dry them for 360 minutes to finally obtain highly silicated glass microspheres with uniform and dense surface coating.

[0017] This comparative example provides a method for preparing glass microspheres with high surface silicification, comprising the following steps: S1. Take 10 g of glass microspheres with a particle size of 10-100 μm, soak them in 10 wt% NaOH and ultrasonicate for 30 min, then rinse them twice with deionized water to obtain pretreated glass microspheres; S2. Add NaOH solution to the pretreated glass microspheres until the pH is 12, take 10 ml of ethyl orthosilicate and disperse it in 20 g of alcohol, slowly add it to the glass microspheres, and then stir at 80°C for 6 hours. After the reaction is completed, separate the glass microspheres by centrifugation, and then place them in an oven at 60°C and dry them for 360 minutes to finally obtain highly silicated glass microspheres with uniform and dense surface coating.

[0018] The above four embodiments and two comparative examples use the same amount of glass microspheres. The difference is that, in Embodiment 1, Embodiment 2, Embodiment 3 and Embodiment 4, different ethyl orthosilicate contents, coating times and reaction temperatures are selected according to the alkali washing, modification and coating methods of the present invention; Comparative Example 1 adopts a direct modification and then coating method, while Comparative Example 2 adopts a direct coating method after alkali washing.

[0019] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing glass microspheres with high surface silicification, characterized in that The steps include: (1) adding the glass microbeads into a sodium hydroxide solution for alkaline washing, and then washing with deionized water to obtain pretreated glass microbeads; (2) Mixing the modifier with deionized water at a mass ratio of 400-600:1-3 to the modifier, stirring evenly to obtain a mixed solution, and then mixing the mixed solution with the glass microbeads obtained in step (1) at a mass ratio of 1-5:10-100, stirring for 2-3 hours to obtain modified glass microbeads; (3) Add the modified glass microbeads to deionized water at a mass ratio of 1-3:200-400, and then add sodium hydroxide solution and ethyl orthosilicate solution thereto, controlling the mass ratio of sodium hydroxide solution to glass to be 10-5:1, and the mass ratio of ethyl orthosilicate solution to glass to be 0.1-1:1-10; stir evenly and react, separate the glass microbeads from the solution after the reaction, and then place them in an oven for drying, finally obtaining highly silicated glass microbeads with a uniform and dense surface coating.

2. The method for preparing glass microspheres with high surface silicification according to claim 1, characterized in that: The number of times of washing with deionized water in step (1) is 2-3 times.

3. The method for preparing glass microspheres with high surface silicification according to claim 1, characterized in that: The particle size of the glass microbeads in step (1) is 10-100 μm.

4. The method for preparing glass microspheres with high surface silicification according to claim 1, characterized in that: The modifier in step (2) is at least one of γ-aminopropyltriethoxysilane, γ-propyltrimethoxysilane, and γ-methacryloyloxypropyl.

5. The method for preparing glass microspheres with high surface silicification according to claim 1, characterized in that: In the step (3), the mass ratio of ethyl orthosilicate to anhydrous ethanol in the ethyl orthosilicate solution is 1:1-3.

6. The method for preparing glass microspheres with high surface silicification according to claim 1, characterized in that: The reaction time in step (3) is 100-600 min.

7. The method for preparing glass microspheres with high surface silicification according to any one of claims 1 to 6, characterized in that: The drying temperature in step (3) is 60-80°C.

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