Preparation method of double-hole silicon dioxide with adjustable proportion

Abstract

The preparation method comprises the following steps: mixing hexadecyl trimethyl ammonium bromide, a sodium hydroxide aqueous solution and an ethanol solution in water, adding a silicon source after 30-40 minutes, stirring for 2-3 hours, carrying out solid-liquid separation, drying the solid overnight, and carrying out heat preservation for 4-5 hours to obtain the ratio-adjustable double-hole silicon dioxide. The silica nanoparticles prepared by the method can be used as a drug carrier due to the unique large and small pore structure, the specific surface area is increased by small pores, the loading of macromolecules is facilitated by the large pores, and the double-pore silica has a certain slow release effect. The silicon dioxide nanoparticles can also be used as a template for preparing the porous polyelectrolyte microcapsule. The preparation method has the characteristics of simple process and low cost, and the silicon dioxide has wide application value in many fields of medicines, pesticides, catalysis, adsorption, light, electricity, magnetism and the like due to the double-hole structure of the silicon dioxide.

Description

Technical Field

[0001] The invention belongs to the field of chemical synthesis, and in particular relates to a method for preparing biporous silica with adjustable proportion. Background Art

[0002] Since Kresge et al. synthesized porous silica materials by self-assembly in cationic surfactant solutions in 1992, the use of organic surfactants as templates to prepare this kind of three-dimensional ordered inorganic materials with controllable pore size has been greatly developed. The pore structure (such as honeycomb, tubular porous, spherical porous, regular 3-D network) and pore size (between a few to tens of nanometers) of porous silica can be adjusted according to actual needs. Vallet-Regi et al. directly used porous silica (MCM-41) for drug loading and release research. By utilizing its high specific surface area, the loading amount of ibuprofen can be as high as 30%.

[0003] The high specific surface area and ordered pores of porous silica are helpful for the adsorption and transport of small molecules, but for large molecules, such as proteins, their size is much larger than the size of the pores, which limits its application range. At the same time, there are also some problems when the pores are large, such as the small specific surface area of ​​the macropores and the reduced adsorption effect. Summary of the invention

[0004] In view of the above problems of the prior art, the present invention provides a method for preparing bi-porous silica with adjustable ratio, which controls the ratio of bi-porous silica by changing the amount of hexadecyltrimethylammonium bromide (CTAB) and ethanol. The unique large and small pore structure of silica makes it possible to be used as a drug carrier, and also as a core template for preparing porous microcapsules by layer-by-layer self-assembly method. Small pores can effectively increase the adsorption amount of small molecules, and large pores are conducive to the loading and adsorption of polymers.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: A method for preparing biporous silica with adjustable ratio comprises the following steps: Mix hexadecyltrimethylammonium bromide, sodium hydroxide aqueous solution and ethanol solution in water, add silicon source after 30-40 minutes, stir for 2-3 hours, separate the solid and liquid, dry the solid overnight, and keep warm for 4-5 hours to obtain the product.

[0006] Furthermore, the silicon source is (3-aminopropyl)triethoxysilane.

[0007] Furthermore, the mass ratio of the hexadecyltrimethylammonium bromide to the silicon source is (0.2-0.65):1.

[0008] Furthermore, the concentration of the sodium hydroxide aqueous solution is 2-2.5 mol / L.

[0009] Furthermore, the mass of the sodium hydroxide aqueous solution is 1.4-1.6 g.

[0010] Furthermore, the mass ratio of ethanol to silicon source in the ethanol solution is (0.6-2.7):1.

[0011] Furthermore, the volume of the water is 192-200 mL, preferably deionized water.

[0012] Furthermore, the insulation temperature is 550-560°C.

[0013] Furthermore, the heat preservation is carried out in a muffle furnace.

[0014] The present invention has the following beneficial effects: The bi-porous silica with adjustable ratio of the present invention has a large and small pore structure, wherein the small pore diameter is 2 to 5 nanometers, and the large pore diameter is 20 to 40 nanometers, and the ratio of the large and small pores can be adjusted. The small pores increase the specific surface area of ​​the silica, improve the adsorption capacity of the guest molecule, and the large pores are conducive to the entry of polymers, can load polymer drugs, and can also carry out the self-assembly of polymer polyelectrolytes. The bi-porous silica can be used as a "micro controlled release carrier" of active substances, can accommodate a large number of guest molecules or polymers, can produce some peculiar properties based on the microscopic "wrapping" effect, so that it has a wide range of application values ​​in many fields such as medicine, pesticides, catalysis, adsorption, light, electricity, and magnetism. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a transmission electron microscope image of the double-porous silica prepared in Example 1.

[0016] Figure 2 This is the nitrogen adsorption-desorption diagram and BJH calculated pore size distribution diagram of the proportional biporous silica prepared in Example 1.

[0017] Figure 3 This is the nitrogen adsorption-desorption diagram and BJH calculated pore size distribution diagram of the biporous silica prepared in Example 2.

[0018] Figure 4 This is the nitrogen adsorption-desorption diagram and BJH calculated pore size distribution diagram of the biporous silica prepared in Example 3.

[0019] Figure 5 This is the nitrogen adsorption-desorption diagram and BJH calculated pore size distribution diagram of the biporous silica prepared in Example 4. DETAILED DESCRIPTION

[0020] The following examples are used to further illustrate the present invention, but are not intended to limit the scope of the present invention. Example

[0021] Weigh 0.4 g hexadecyltrimethylammonium bromide, 1.4 g 2 mol / L sodium hydroxide aqueous solution, and 15.6 g ethanol solution (7.5%) and mix them in 192 mL of deionized water. After 30 min, add 1.89 g (3-aminopropyl)triethoxysilane, stir at room temperature for 2 h, centrifuge and dry overnight, and keep the temperature in a muffle furnace at 550 °C for 5 h to remove hexadecyltrimethylammonium bromide. The first ratio of double-porous silica is obtained as Figure 2 . Example

[0022] Weigh 0.6 g hexadecyltrimethylammonium bromide, 1.4 g 2 mol / L sodium hydroxide aqueous solution, and 21.3 g ethanol solution (10%) and mix them in 192 mL of deionized water. Half an hour later, add 1.89 g (3-aminopropyl)triethoxysilane, stir at room temperature for 2 h, centrifuge and dry overnight, and keep the temperature in a muffle furnace at 550 °C for 5 h to remove hexadecyltrimethylammonium bromide. The second ratio of double-porous silica is obtained as Figure 3 . Example

[0023] Weigh 0.8 g hexadecyltrimethylammonium bromide, 1.4 g 2 mol / L sodium hydroxide aqueous solution, and 26.2 g ethanol solution (12%) and mix them in 192 mL of deionized water. Half an hour later, add 1.89 g (3-aminopropyl)triethoxysilane, stir at room temperature for 2 h, centrifuge and dry overnight, and keep the temperature at 550 °C in a muffle furnace for 5 h to remove hexadecyltrimethylammonium bromide. The third ratio of double-porous silica is obtained, such as Figure 4 . Example

[0024] Weigh 1.2 g hexadecyltrimethylammonium bromide, 1.4 g 2 mol / L sodium hydroxide aqueous solution, and 33.9 g ethanol solution (15%) and mix them in 192 mL of deionized water. Half an hour later, add 1.89 g (3-aminopropyl)triethoxysilane, stir at room temperature for 2 h, centrifuge and dry overnight, and heat the muffle furnace at 550 °C for 5 h to remove hexadecyltrimethylammonium bromide. The fourth ratio of double-porous silica is obtained as Figure 5 .

Claims

1. A method for preparing bi-porous silica with adjustable ratio, characterized in that: The steps include: Mix hexadecyltrimethylammonium bromide, sodium hydroxide aqueous solution and ethanol solution in water, add silicon source after 30-40 minutes, stir for 2-3 hours, separate the solid and liquid, dry the solid overnight, and keep warm for 4-5 hours to obtain the product.

2. The preparation method according to claim 1, characterized in that: The silicon source is (3-aminopropyl)triethoxysilane.

3. The preparation method according to claim 1, characterized in that: The mass ratio of the hexadecyltrimethylammonium bromide to the silicon source is (0.2-0.65):

1.

4. The preparation method according to claim 1, characterized in that The concentration of the sodium hydroxide aqueous solution is 2-2.5 mol / L.

5. The preparation method according to claim 1, characterized in that The mass of the sodium hydroxide aqueous solution is 1.4-1.6 g.

6. The preparation method according to claim 1, characterized in that: The mass ratio of ethanol to silicon source in the ethanol solution is (0.6~2.7):

1.

7. The preparation method according to claim 1, characterized in that The volume of the water is 192-200 mL.

8. The preparation method according to claim 1, characterized in that The insulation temperature is 550-560°C.

9. The preparation method according to claim 1, characterized in that: The heat preservation is carried out in a muffle furnace.

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