Preparation method of porous silicon dioxide microspheres

Abstract

The invention discloses a preparation method of porous silicon dioxide microspheres, which comprises the following steps: firstly, synthesizing SiO2 with a porous structure, and regulating and controlling the granularity and pore structure of the porous structure by controlling the types of precursors, the proportion of each precursor and reaction regulation and control; then carrying out heat treatment to obtain porous SiO2 microspheres; the preparation method comprises the following steps: in an ethanol solution, carrying out surface modification on SiO2 microspheres by using organic silicon to obtain organic silicon modified SiO2 microspheres; finally, traditional Chinese medicine extract dipping-freeze drying is used for modification, and the functionalized porous SiO2 microspheres are obtained. The prepared porous SiO2 microspheres have very high oil absorption value and spreadability on one hand, can be used for cosmetics after being modified by traditional Chinese medicine extracts with anti-inflammation and detumescence effects on the other hand, have the functions of concealing, whitening and shielding ultraviolet rays on the one hand, and can diminish inflammation and prevent skin minimally invasive wound inflammation during long-term use on the other hand.

Description

Technical Field

[0001] The invention relates to the field of nano material preparation, in particular to a method for preparing porous silicon dioxide microspheres. Background Art

[0002] Silica microspheres have been widely used in the fields of adsorbents, pigments, cosmetics, and medicine. In some application fields, there are relatively high requirements for the size, pore structure, and dispersion of silica in the medium. For example, for oil control and oil absorption in cosmetics, silica needs to have a very large specific surface area and needs to be evenly dispersed in an ethanol solution. However, conventional synthetic silica methods are difficult to meet the above requirements. Therefore, the development of silica materials with high specific surface area, high oil absorption value, and good dispersibility is extremely important for realizing its application in various fields.

[0003] In view of the shortcomings of current silica materials and their application fields, porous SiO2 spheres are constructed by combining nano-preparation technology and surface modification technology. Their dispersibility in ethanol is promoted through surface modification. In addition, by modifying them with Chinese herbal extracts with anti-inflammatory effects, the SiO2 microspheres can be given anti-inflammatory functions. Summary of the invention

[0004] The present invention aims to provide a method for preparing porous silica microspheres, a method for preparing porous SiO2 spheres with good dispersibility.

[0005] The object of the present invention is achieved by the following scheme: A method for preparing porous silica microspheres comprises the following steps: Step 1: Take 1.0-1.8 g of hexadecyltrimethylammonium bromide and dissolve it in an ethanol solution of ethanol and deionized water. After dissolution, add 0.8-1.3 g of resorcinol, stir evenly, add 0.3-0.5 mL of ammonia water, stir for 20 min, add 0.8-2.1 mL of formaldehyde, stir for 10 min, add 2-3.6 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 60-90 ° C for 24 h. After the reaction is completed, the obtained precipitate is centrifuged and washed with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous structure SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then perform heat treatment at a temperature of 550-650°C, a time of 5-7 h, and a heating rate of 1°C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of tetraethyl orthosilicate and stir for 30 min, then add organosilicon so that the mass ratio of organosilicon to SiO2 is 0.8-1.2:100, seal, stir at room temperature for 16-20 h, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: After the sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, it is freeze-dried at -80°C and ground. The immersion-freeze-drying-grinding steps are repeated many times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

[0006] The method of the present invention first synthesizes SiO2 with a porous structure, and regulates the particle size and pore structure of the porous structure by controlling the type of precursors and the proportion of each precursor, and then performs heat treatment to obtain porous SiO2 microspheres, and then uses silicone to modify the surface of the SiO2 microspheres in an ethanol solution to obtain silicone-modified SiO2 microspheres, and then uses a traditional Chinese medicine extract with anti-inflammatory and detumescent effects to immerse and freeze-dry for modification to obtain functional porous SiO2 microspheres.

[0007] In step 1, the volumes of the ethanol and deionized water are 40-46 mL and 13-18 mL, respectively.

[0008] In step 2, the heat treatment is: heat treatment in an inert gas for 1 to 2 hours, and then heat treatment in air for 3 to 6 hours, and the total heat treatment time of the two steps is 5 to 7 hours.

[0009] In step 3, the organosilicon is at least one of phenyltrimethoxysilane, ethylenetrimethoxysilane, hexamethyldisilazane, 3-mercaptopropyltriethoxysilane, and (3-aminopropyl)trimethoxysilane.

[0010] The porous SiO2 microspheres prepared by the present invention have very high oil absorption value and spreadability. In addition, they are modified with Chinese herbal extracts with anti-inflammatory and detumescent effects and can be used in cosmetics. On the one hand, they have the functions of concealing blemishes, whitening, and blocking ultraviolet rays. On the other hand, they can reduce inflammation and prevent inflammation of micro-wounds on the skin during long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the SEM picture of the sample obtained in Example 1 of the present invention. It can be seen from the figure that the diameter of the obtained sample is about 0.5um, and there are a large number of pore structures on the surface of the ball. The existence of the pore structure is beneficial to increasing the oil absorption value of the material. DETAILED DESCRIPTION

[0012] Embodiment 1: A porous silica microsphere is prepared according to the following steps: Step 1: Take 1.0 g of hexadecyltrimethylammonium bromide and dissolve it in a mixture of 44 mL of ethanol and 16 mL of deionized water. After dissolution, add 1.0 g of resorcinol, stir evenly, add 0.4 mL of ammonia water, stir for 20 min, add 1.5 mL of formaldehyde, stir for 10 min, add 3.6 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 80°C for 24 h. After the reaction is completed, the obtained precipitate is centrifuged and washed with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then heat treat it at a temperature of 650 °C in an inert gas atmosphere for 2 h, then heat treat it in air for 4 h at a heating rate of 1 °C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of tetraethyl orthosilicate and stir for 30 min, then add (3-aminopropyl)trimethoxysilane, the mass ratio of (3-aminopropyl)trimethoxysilane to silicon dioxide is 1.0:100, seal, stir at room temperature for 20 h, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: The sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, then freeze-dried at -80°C, ground, and the immersion-freeze-drying-grinding steps are repeated three times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

[0013] The SEM images of the obtained product samples are as follows: Figure 1 As shown in the figure, it can be seen that the diameter of the obtained sample is about 0.5 um, and there are a large number of pore structures on the surface of the ball. The existence of this pore structure is beneficial to increasing the oil absorption value of the material.

[0014] The oil absorption value of the organosilicon-modified SiO2 porous microspheres obtained in this example is 3.6 ml / g.

[0015] Embodiment 2: A porous silica microsphere is prepared according to the following steps: Step 1: Take 1.8 g of hexadecyltrimethylammonium bromide and dissolve it in a mixture of 40 mL of ethanol and 18 mL of deionized water. After dissolution, add 1.3 g of resorcinol, stir evenly, add 0.5 mL of ammonia water, stir for 20 min, add 0.8 mL of formaldehyde, stir for 10 min, add 3.6 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 80 ° C for 24 h. After the reaction is completed, the obtained precipitate is washed by centrifugation with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous structure SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then heat treat it at a temperature of 600 °C in an inert gas atmosphere for 1 h, then heat treat it in air for 4 h at a heating rate of 1 °C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of tetraethyl orthosilicate and stir for 30 min, then add phenyltrimethoxysilane, the mass ratio of phenyltrimethoxysilane to silicon dioxide is 1.2:100, seal, stir at room temperature for 20 h, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: The sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, then freeze-dried at -80°C and ground. The soaking-freeze-drying-grinding steps are repeated three times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

[0016] The oil absorption value of the organosilicon-modified SiO2 porous microspheres obtained in this example is 3.5 ml / g.

[0017] Embodiment 3: A porous silica microsphere is prepared according to the following steps: Step 1: Take 1.0 g of hexadecyltrimethylammonium bromide and dissolve it in a mixture of 44 mL of ethanol and 16 mL of deionized water. After dissolution, add 1.3 g of resorcinol, stir evenly, add 0.3 mL of ammonia water, stir for 20 min, add 0.9 mL of formaldehyde, stir for 10 min, add 2.5 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 80 ° C for 24 h. After the reaction is completed, the obtained precipitate is centrifuged and washed with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous structure SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then heat treat it at a temperature of 650 °C in an inert gas atmosphere for 1 h, then heat treat it in air for 6 h at a heating rate of 1 °C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of tetraethyl orthosilicate and stir for 30 min, then add (3-aminopropyl)trimethoxysilane, the mass ratio of (3-aminopropyl)trimethoxysilane to silicon dioxide is 0.8:100, seal, stir at room temperature for 20 h, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: The sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, then freeze-dried at -80°C and ground. The soaking-freeze-drying-grinding steps are repeated four times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

[0018] The oil absorption value of the organosilicon-modified SiO2 porous microspheres obtained in this example is 3.75 ml / g.

[0019] The description of the above embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made to the present invention by those skilled in the art based on the disclosure of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing porous silica microspheres, characterized in that: The steps include: Step 1: Take 1.0-1.8 g of hexadecyltrimethylammonium bromide and dissolve it in an ethanol solution of ethanol and deionized water. After dissolution, add 0.8-1.3 g of resorcinol, stir evenly, add 0.3-0.5 mL of ammonia water, stir for 20 min, add 0.8-2.1 mL of formaldehyde, stir for 10 min, add 2-3.6 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 60-90 ° C for 24 h. After the reaction is completed, the obtained precipitate is centrifuged and washed with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous structure SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then perform heat treatment at a temperature of 550-650°C, a time of 5-7 hours, and a heating rate of 1°C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of ethyl orthosilicate and stir for 30 minutes, then add organosilicon so that the mass ratio of organosilicon to SiO2 is 0.8-1.2:100, seal, stir at room temperature for 16-20 hours, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: After the sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, it is freeze-dried at -80°C and ground. The immersion-freeze-drying-grinding steps are repeated many times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

2. The method for preparing porous silica microspheres according to claim 1, characterized in that: In step 1, the volumes of the ethanol and deionized water are 40-46 mL and 13-18 mL, respectively.

3. The method for preparing porous silica microspheres according to claim 1, characterized in that: In step 2, during the heat treatment, the atmosphere is first heat treated in an inert gas for 1 to 2 hours, and then heat treated in air for 3 to 6 hours. The total time of the two-step heat treatment is 5 to 7 hours.

4. The method for preparing porous silica microspheres according to claim 1, characterized in that: In step 3, the organosilicon is at least one of phenyltrimethoxysilane, ethylenetrimethoxysilane, hexamethyldisilazane, 3-mercaptopropyltriethoxysilane, and (3-aminopropyl)trimethoxysilane.

5. The method for preparing porous silica microspheres according to any one of claims 1 to 4, characterized in that: Prepare as follows: Step 1: Take 1.0 g of hexadecyltrimethylammonium bromide and dissolve it in a mixture of 44 mL of ethanol and 16 mL of deionized water. After dissolution, add 1.0 g of resorcinol, stir evenly, add 0.4 mL of ammonia water, stir for 20 min, add 1.5 mL of formaldehyde, stir for 10 min, add 3.6 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 80 ° C for 24 h. After the reaction is completed, the obtained precipitate is centrifuged and washed with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous structure SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then heat treat it at a temperature of 650 °C in an inert gas atmosphere for 2 h, then heat treat it in air for 4 h at a heating rate of 1 °C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of tetraethyl orthosilicate and stir for 30 minutes, then add (3-aminopropyl)trimethoxysilane, the mass ratio of (3-aminopropyl)trimethoxysilane to silicon dioxide is 1.0:100, seal, stir at room temperature for 20 hours, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: The sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, then freeze-dried at -80°C, ground, and the immersion-freeze-drying-grinding steps are repeated three times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

6. The method for preparing porous silica microspheres according to any one of claims 1 to 4, characterized in that: Prepare as follows: Step 1: Take 1.8 g of hexadecyltrimethylammonium bromide and dissolve it in a mixture of 40 mL of ethanol and 18 mL of deionized water. After dissolution, add 1.3 g of resorcinol, stir evenly, add 0.5 mL of ammonia water, stir for 20 min, add 0.8 mL of formaldehyde, stir for 10 min, add 3.6 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 80 ° C for 24 h. After the reaction is completed, the obtained precipitate is centrifuged and washed with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous structure SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then heat treat it at a temperature of 600 °C in an inert gas atmosphere for 1 h, then heat treat it in air for 4 h at a heating rate of 1 °C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of tetraethyl orthosilicate and stir for 30 minutes, then add phenyltrimethoxysilane, the mass ratio of phenyltrimethoxysilane to silicon dioxide is 1.2:100, seal, stir at room temperature for 20 hours, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: The sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, then freeze-dried at -80°C and ground. The soaking-freeze-drying-grinding steps are repeated three times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

7. The method for preparing porous silica microspheres according to any one of claims 1 to 4, characterized in that: Prepare as follows: Step 1: Take 1.0 g of hexadecyltrimethylammonium bromide and dissolve it in a mixture of 44 mL of ethanol and 16 mL of deionized water. After dissolution, add 1.3 g of resorcinol, stir evenly, add 0.3 mL of ammonia water, stir for 20 min, add 0.9 mL of formaldehyde, stir for 10 min, add 2.5 mL of tetraethyl orthosilicate, seal, and hydrothermally react at 80 ° C for 24 h. After the reaction is completed, the obtained precipitate is centrifuged and washed with deionized water and ethanol respectively, and then placed in a blast drying oven to obtain a dried porous SiO2 powder; Step 2: Grind the dried powder obtained in step 1 and then heat treat it at a temperature of 650 °C in an inert gas atmosphere for 1 h, then heat treat it in air for 6 h at a heating rate of 1 °C / min to obtain a SiO2 microsphere sample; Step 3: Take 2 g of the sample obtained in step 2, place it in anhydrous ethanol, add 0.1 mL of tetraethyl orthosilicate and stir for 30 minutes, then add (3-aminopropyl)trimethoxysilane, the mass ratio of (3-aminopropyl)trimethoxysilane to silicon dioxide is 0.8:100, seal, stir at room temperature for 20 hours, centrifuge after the reaction is completed, take the precipitate, centrifuge the precipitate with deionized water and anhydrous ethanol respectively, and then dry it by spray drying to obtain organosilicon-modified SiO2 microspheres; Step 4: The sample obtained in step 3 is immersed in extracts of Bletilla striata and Salvia miltiorrhiza, then freeze-dried at -80°C and ground. The soaking-freeze-drying-grinding steps are repeated four times to obtain functionalized porous SiO2 microspheres with anti-inflammatory effects.

8. A porous SiO2 microsphere obtained according to any one of the preparation methods of claims 1 to 7.

9. Use of the porous SiO2 microspheres according to claim 8 in cosmetics, which have the functions of concealing blemishes, whitening, and blocking ultraviolet rays, and on the other hand, reduce inflammation and prevent inflammation of micro-wounds on the skin during long-term use.

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