Hydrophobic silica powder and preparation method thereof
Environmentally friendly and efficient hydrophobic silica micropowder was prepared by the mixed aging centrifugal drying method of silica micropowder and hexamethyldisilazane, which solved the problems of complex process and high environmental toxicity in the existing technology and achieved efficient hydrophobic performance in multiple scenarios.
Patent Information
- Application Number
- CN202511135051.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-13
- Publication Date
- 2025-10-17
AI Technical Summary
Existing technologies for preparing hydrophobic materials have problems such as complex processes, high costs, high environmental toxicity, and difficulty in balancing fluorine-free environmental protection and ultra-low surface energy, making it difficult to achieve efficient hydrophobic performance in multiple scenarios.
Hydrophobic silica powders with different wettabilities were prepared by using a mixture of silica powder, ethanol and hexamethyldisilazane through aging, centrifugation and drying, and by controlling the amount of hexamethyldisilazane.
The prepared hydrophobic silicon micropowder has uniform particle size, is environmentally friendly and pollution-free, and is suitable for the fields of construction, energy and aviation. It reduces the surface dirt adhesion rate, reduces the risk of battery short circuit and ice adhesion, improves fuel efficiency, has low cost and simple process.
Smart Images
Figure CN120793948A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of hydrophobic materials, and in particular to hydrophobic silicon micropowder and a preparation method thereof. Background Art
[0002] Hydrophobic materials (contact angle > 90°), especially super-hydrophobic materials (contact angle > 150°), have important application value in the fields of self-cleaning, oil-water separation, air filtration and drug delivery. Micron hydrophobic particles are the core elements for constructing such functional materials. They achieve efficient hydrophobic properties through the synergistic effect of micro- and nano-rough structures and low surface energy. However, existing preparation technologies have significant limitations, process complexity and environmental risks: mainstream methods (such as sol-gel method and chemical vapor deposition) rely on multi-step high-temperature and high-pressure processes, and fluorine-containing compounds (such as fluorocarbon resins) are generally used to reduce surface energy, resulting in high energy consumption, high cost and environmental toxicity (fluorine-containing substances are difficult to degrade and easily bioaccumulate).
[0003] Current technologies struggle to overcome three major contradictions: simplification of the process and performance improvement are difficult to achieve, fluorine-free and environmentally friendly properties cannot be balanced with ultra-low surface energy, and universal preparation and functional specificity are mutually constrained. Therefore, there is an urgent need to develop a method for preparing micron hydrophobic particles that is simple, environmentally friendly, stable in performance, and applicable to multiple scenarios. Summary of the Invention
[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a hydrophobic silicon micropowder and a preparation method thereof.
[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0006] The present invention provides a method for preparing hydrophobic silicon micropowder, comprising the following steps:
[0007] (1) mixing silicon micropowder, ethanol and hexamethyldisilazane to obtain a mixed system;
[0008] (2) mixing the mixed system with water and then aging to obtain an aged system;
[0009] (3) The aged system is centrifuged and dried sequentially to obtain the hydrophobic silicon powder.
[0010] Preferably, the mass volume ratio of the silicon powder, ethanol and hexamethyldisilazane in step (1) is 2g:30mL:0.1-8mL.
[0011] Preferably, the particle size of the silicon powder in step (1) is 1 to 1000 μm.
[0012] Preferably, the stirring time of the mixing in step (1) is ≥30 min.
[0013] As preferred, the volume ratio of the water in step (2) to the ethanol in step (1) is 1:8-12.
[0014] As preferred, the stirring time of the mixing in step (2) is ≥1h.
[0015] As preferred, the temperature of the aging in step (2) is 20-30℃, and the time is ≥24h.
[0016] As preferred, the rotation speed of the centrifugation in step (3) is ≥2500rpm, and the time is ≥10min.
[0017] As preferred, the temperature of the drying in step (3) is ≥80℃.
[0018] The application also provides the hydrophobic silicon micropowder prepared by the preparation method of the hydrophobic silicon micropowder.
[0019] The application provides a preparation method of a hydrophobic silicon micropowder, which comprises the following steps: mixing silicon micropowder, ethanol and hexamethyldisilazane to obtain a mixed system; mixing the mixed system and water and then aging to obtain an aged system; and sequentially performing centrifugation and drying on the aged system to obtain the hydrophobic silicon micropowder. By controlling the amount of hexamethyldisilazane, the hydrophobic silicon micropowder with different wettability can be prepared, which can well meet the needs of the fields of building, energy and aviation, and has a wide application prospect. In the field of building, as an additive of super-hydrophobic self-cleaning concrete, the "lotus effect" is realized by repelling water, the surface dirt adhesion rate is significantly reduced, and the cleaning frequency of the building outer wall is reduced; in the field of energy, the hydrophobic silicon micropowder is used for the electrolyte coating of the lithium battery separator to block the penetration of the electrolyte to the electrode, reduce the risk of short circuit of the battery, and prolong the cycle life; in the field of aviation, the hydrophobic silicon micropowder is used for preparing an ice-proof and drag-reducing coating of a wing to reduce the adhesion strength of the ice layer and reduce the air friction resistance, thereby improving the fuel efficiency. In addition, the preparation process of the application is simple, the reactants are easy to obtain, the production cost is low, the reaction conditions are easy to realize, no pollutants are generated in the reaction process, the hydrophobic silicon micropowder prepared has uniform particle size, the core technical bottleneck problems such as dependence on fluorine-containing materials and multi-step reaction in the traditional process are well solved, the conversion rate is high, the equipment is simple, and the application has good environmental and economic benefits. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is a contact angle test diagram of the unmodified silicon micropowder in Example 1;
[0021] Figure 2 It is a contact angle test diagram of the hydrophobic silicon micropowder in Example 1;
[0022] Figure 3 It is a contact angle test diagram of the hydrophobic silicon micropowder in Example 2;
[0023] Figure 4 Figure. 1 is a diagram for the contact angle test of the hydrophobic silica fume in Example 3. DETAILED DESCRIPTION
[0024] The present application provides a method for preparing a hydrophobic silica fume, comprising the following steps:
[0025] (1) mixing silica fume, ethanol and hexamethyldisilazane to obtain a mixed system;
[0026] (2) mixing the mixed system with water and then aging to obtain an aged system;
[0027] (3) sequentially centrifuging and drying the aged system to obtain the hydrophobic silica fume.
[0028] In the present application, the mass-volume ratio of the silica fume, ethanol and hexamethyldisilazane in step (1) is preferably 2 g: 30 mL: 0.1-8 mL, further preferably 2 g: 30 mL: 1-7 mL, and more preferably 2 g: 30 mL: 3-5 mL.
[0029] In the present application, the particle size of the silica fume in step (1) is preferably 1-1000 μm, further preferably 100-900 μm, and more preferably 400-600 μm.
[0030] In the present application, the stirring time of the mixing in step (1) is preferably ≥ 30 min, further preferably ≥ 40 min, and more preferably ≥ 50 min.
[0031] In the present application, the volume ratio of the water in step (2) to the ethanol in step (1) is preferably 1: 8-12, further preferably 1: 9-11, and more preferably 1: 9.5-10.5.
[0032] In the present application, the stirring time of the mixing in step (2) is preferably ≥ 1 h, further preferably ≥ 5 h, and more preferably ≥ 10 h.
[0033] In the present application, the temperature of the aging in step (2) is preferably 20-30 °C, further preferably 22-28 °C, and more preferably 24-26 °C; and the time is preferably ≥ 24 h, further preferably ≥ 30 h, and more preferably ≥ 36 h.
[0034] In the present application, the rotation speed of the centrifugation in step (3) is preferably ≥ 2500 rpm, further preferably ≥ 3000 rpm, and more preferably ≥ 3500 rpm; and the time is preferably ≥ 10 min, further preferably ≥ 20 min, and more preferably ≥ 30 min.
[0035] In the present application, solid particles are obtained by centrifugation in step (3), and the solid particles are washed with ethanol, followed by drying in the next step.
[0036] In the present application, the temperature in step (3) is preferably ≥ 80°C, further preferably ≥ 85°C, and more preferably ≥ 90°C; and the drying is continued until a constant weight is obtained to obtain the hydrophobic silica fume.
[0037] The present application also provides the hydrophobic silica fume prepared by the preparation method.
[0038] The technical solutions provided by the present application will be described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present application.
[0039] Example 1
[0040] In this example, the particle size of the silica fume is 25 μm, 2 g of the silica fume and 0.3 ml of hexamethyldisilazane are added to 30 ml of anhydrous ethanol, and after stirring for 30 min, 3 ml of deionized water is added. After stirring vigorously for 2 h, the aging system is obtained by standing at 25°C for 24 h. The solid particles are obtained by centrifuging the aging system at 2500 rpm for 15 min, and the solid is washed with anhydrous ethanol, and then dried at 80°C until a constant weight is obtained to obtain the hydrophobic silica fume.
[0041] As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°. Figure 1 As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°. Figure 2 As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°. Figure 1 As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°. Figure 2 As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°.
[0042] Example 2
[0043] In this example, the particle size of the silica fume is 25 μm, 2 g of the silica fume and 0.3 ml of hexamethyldisilazane are added to 30 ml of anhydrous ethanol, and after stirring for 30 min, 3 ml of deionized water is added. After stirring vigorously for 2 h, the aging system is obtained by standing at 25°C for 24 h. The solid particles are obtained by centrifuging the aging system at 2500 rpm for 15 min, and the solid is washed with anhydrous ethanol, and then dried at 80°C until a constant weight is obtained to obtain the hydrophobic silica fume.
[0044] As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°. Figure 3 As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°. Figure 3 As shown in Table 1, the contact angle of the silica fume before treatment is 5°, and the contact angle of the hydrophobic silica fume after treatment is 132.5°.
[0045] Example 3
[0046] The silicon micropowder used in the example has a particle size of 25 μm. 2 g of the silicon micropowder and 8 ml of hexamethyldisilazane were added to 30 ml of anhydrous ethanol, stirred for 30 min, then 3 ml of deionized water was added, and after strong stirring for 2 h, the system was allowed to stand and age at 25°C for 24 h to obtain an aging system. The aging system was centrifuged at 2500 rpm for 15 min to obtain solid particles, the solid was washed with anhydrous ethanol, and then dried at 80°C to constant weight to obtain hydrophobic silicon micropowder.
[0047] The contact angle of the hydrophobic silicon micropowder prepared in the example is shown in Table 1. Figure 4 Figure 4 As can be seen from Table 1, the contact angle of the hydrophobic silicon micropowder is 154°.
[0048] The above description is only preferred embodiments of the present application, and it should be pointed out that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.
Claims
1. A method for preparing hydrophobic silicon micropowder, characterized in that: It includes the following steps: (1) mixing silicon micropowder, ethanol and hexamethyldisilazane to obtain a mixed system; (2) mixing the mixed system with water and then aging to obtain an aged system; (3) The aged system is centrifuged and dried sequentially to obtain the hydrophobic silicon powder.
2. The method for preparing hydrophobic silicon powder according to claim 1, wherein The mass volume ratio of the silicon micropowder, ethanol and hexamethyldisilazane in step (1) is 2g:30mL:0.1-8mL.
3. The method for preparing hydrophobic silicon powder according to claim 2, wherein: The particle size of the silicon micropowder in step (1) is 1 to 1000 μm.
4. The method for preparing hydrophobic silicon powder according to claim 3, wherein: The stirring time of the mixing in step (1) is ≥30 min.
5. The method for preparing hydrophobic silicon powder according to claim 4, wherein: The volume ratio of the water in step (2) to the ethanol in step (1) is 1:8-12.
6. The method for preparing hydrophobic silicon powder according to claim 5, wherein: The stirring time of the mixing in step (2) is ≥1h.
7. The method for preparing hydrophobic silicon powder according to claim 6, wherein: The aging temperature in step (2) is 20-30° C. and the time is ≥24 h.
8. The method for preparing hydrophobic silicon powder according to claim 7, wherein: The centrifugal speed in step (3) is ≥2500 rpm and the time is ≥10 min.
9. The method for preparing hydrophobic silicon powder according to claim 8, wherein: The drying temperature in step (3) is ≥80°C.
10. The hydrophobic silicon micropowder prepared by the method for preparing the hydrophobic silicon micropowder according to any one of claims 1 to 9.