Method for regulating and controlling sizes of mesoporous organic silicon dioxide nanoparticles

Abstract

The invention provides a method for regulating and controlling the size of mesoporous organic silicon dioxide nano-particles, and belongs to the field of nano device preparation, the method regulates and controls the size of the mesoporous organic silicon dioxide nano-particles by controlling the dosage of triethanolamine, and the method specifically comprises the following steps: dropwise adding triethanolamine into an aqueous solution in which a template agent is dissolved; dropwise adding TEOS (tetraethyl orthosilicate) and stirring for reaction; dropwise adding a mixture of BTESPD and TEOS into the reaction product, and stirring for reaction; and washing the obtained product and removing the template agent in the product. According to the method, the size of the mesoporous organic silicon dioxide nanoparticles can be regulated and controlled within the range of 40-130 nm by regulating and controlling the content of triethanolamine in a reaction system, the preparation method is simple, and the prepared product is uniform in morphology and particle size, has macro preparation potential and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of nano device preparation, and in particular to a method for regulating the size of mesoporous organic silica nanoparticles. Background Art

[0002] Mesoporous silica nanoparticles (MSNs) have broad application prospects in fields such as biomedicine and energy catalysis due to their unique mesoporous structure, large surface area, and easily functionalized surface. Unlike inorganic mesoporous silica nanoparticles, mesoporous organic silica nanoparticles (MONs) contain degradable organic groups. These groups can degrade upon stimulation by specific chemicals (such as glutathione (GSH) or acids) or external factors (such as light), enabling controlled release of their internally loaded substances. Consequently, they have garnered significant attention in the field of nano-drug delivery. Research has shown that the size of MSNs determines their application. For example, the particle size of nano-drug delivery systems used for targeted tumor therapy determines their targeting efficiency in different tissues.

[0003] Currently, the preparation methods of MONs mainly include sol-gel method, hydrothermal synthesis method and microemulsion method. Among them, sol-gel method is the most commonly used method due to its relatively mild reaction conditions. For example, Zhang et al. used triethanolamine as a catalyst and co-condensed tetraethoxysilane (TEOS) and bis(3-triethoxypropylsilyl)tetrasulfide to prepare mesoporous organic silica nanoparticles with a particle size of 50 nm (paper, J. Mater. Chem. B, 2017 , 5, 8013–8025). In addition, Ghandehari et al. prepared mesoporous organic silica nanoparticles with particle sizes of 110 nm and 60 nm by co-condensation of TEOS and bis[3-(triethoxysilyl)propyl]tetrasulfide and regulating the content of sodium hydroxide (paper, ACS Appl. Mater. Interfaces , 2017, 9 , 21133–21146). The above methods all use a one-pot process to prepare MONs, which makes it difficult to achieve a large-scale control of particle size. Summary of the Invention

[0004] In view of the technical problems existing in the background technology, the present invention provides a method for regulating the size of mesoporous organic silica nanoparticles, aiming to solve the technical problem that the size of MONs is difficult to be effectively controlled.

[0005] The technical solutions of the present invention are as follows: A method for regulating the size of mesoporous organic silica nanoparticles, namely regulating the size of mesoporous organic silica nanoparticles by the dosage of triethanolamine (TEA), the method comprising the following steps: S1, after adding triethanolamine dropwise to the aqueous solution in which the template is dissolved, TEOS is added dropwise and stirred for reaction; S2. Add a mixture of bis[3-(triethoxysilyl)propyl]disulfide (BTESPD) and TEOS dropwise to the reaction product of step S1 and stir to react; S3, washing the product obtained in step S2, and then removing the template in the product to obtain mesoporous organic silica nanoparticles.

[0006] This paper develops a two-step sol-gel method for preparing mesoporous organosilica nanoparticles. First, triethanolamine is used to catalyze the hydrolysis and polycondensation of TEOS to form small seeds. Then, a mixture of TEOS and BTESPD is added to the seed surface for further co-polycondensation and growth. More importantly, this method, under specific conditions, effectively establishes a good linear relationship between triethanolamine dosage and mesoporous organosilica nanoparticle size. This allows the targeted synthesis of mesoporous organosilica nanoparticles of a specific size simply by adjusting the triethanolamine dosage. Using this method, uniform mesoporous organosilica nanoparticles with an average particle size ranging from 40 to 130 nm can be prepared.

[0007] Preferably, in the above method, the volume ratio of TEOS used in step S1 to the mixture used in step S2 is 1:4, and the volume ratio of BTESPD and TEOS in the mixture is 1:3.

[0008] Preferably, in the above method, the reaction temperature of step S1 is 50-100°C, and the reaction time is 0.5-1.5 h; the reaction temperature of step S2 is 50-100°C, and the reaction time is 2-4 h.

[0009] For example, in some embodiments of the present invention, the amount of TEOS used in step S2 is 1 mL, the volume of the mixture used in step S3 is 4 mL, the reaction temperature in step S1 is 90° C. and the reaction time is 1 h, and the reaction temperature in step S2 is 90° C. and the reaction time is 3 h. Under the above-mentioned conditions, the dosage of triethanolamine and the particle size of the mesoporous organic silica nanoparticles satisfy the following relationship:

[0010] Wherein, y is the particle size of mesoporous organic silica nanoparticles (in nm), and x is the amount of triethanolamine used (in μL).

[0011] Preferably, in step S3 of the above method, ethanol is used for washing.

[0012] In the above method, the template agent is CTAC (cetyltrimethylammonium chloride), CTAB (cetyltrimethylammonium bromide), DTAC (dodecyltrimethylammonium chloride), TTAC (tetradecyltrimethylammonium chloride), STAC (octadecyltrimethylammonium chloride), DDAC (didecyldimethylammonium chloride), BDAC (benzyldimethylhexadecylammonium chloride), CPC (cetylpyridinium chloride), etc. In some embodiments of the present invention, the template agent is CTAC, and the method for removing the template agent in step S3 is to remove the template agent by refluxing 1% concentrated hydrochloric acid and 99% ethanol.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention is relatively simple and has the potential for large-scale production. The present invention allows for the size of mesoporous organic silica nanoparticles to be regulated within a wide range of 40-130 nm, with high uniformity. The prepared mesoporous organic silica nanoparticles have broad application prospects. For example, in the biomedical field, they can precisely deliver drugs and assist in gene therapy; in energy catalysis, they can improve fuel cell efficiency and facilitate chemical industry upgrades; in environmental remediation, they can adsorb pollutants and repair soils, connecting multiple industries and generating massive business opportunities; and in the sensor field, they can be used to detect gases and biomolecules based on their adsorption electrical and optical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0015] Figure 1 : SEM images of the mesoporous organic silica nanoparticles prepared in Examples 1, 2, 3, 4, and 5 of the present invention, where the scale bar is 100 nm; Figure 2 : is a pore size distribution diagram of the mesoporous organic silica nanoparticles prepared in Example 1 of the present invention; Figure 3 is a linear relationship diagram between the dosage of triethanolamine and the particle size of mesoporous organic silica nanoparticles in various embodiments of the present invention; Figure 4 3 are SEM images of the mesoporous organic silica nanoparticles prepared in Comparative Examples 1 and 2 of the present invention, where the scale bar is 200 nm. Specific implementation method 1 The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains; the terms used herein are only for describing specific embodiments and purposes and are not intended to limit the present invention; the term "include" and any variations thereof herein are intended to cover non-exclusive inclusions.

[0018] Some specific examples are listed below. It should be noted that the examples described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product specifications were used. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased commercially.

[0019] Example 1 This example provides a method for preparing 100 nm mesoporous organic silica nanoparticles, which specifically includes the following steps: (1) Dissolve 2.4 mL of CTAC in 40 mL of ultrapure water in a 100 mL round-bottom flask and stir at room temperature (15 min, 800 rpm); (2) After the oil bath is heated to 90°C, 25 μL of triethanolamine is slowly added dropwise using a pipette and stirred for 0.5 h. (3) Slowly add 1 mL of TEOS and stir at 90°C for 1 h; (4) Mix 1 mL of BTESPD and 3 mL of TEOS, slowly add the mixture to the reaction solution in step (3) using a rubber-tipped pipette, and react at 90°C for 3 h. (5) After the reaction in step (4) is completed, filter and wash the product with ethanol three times; then mix 1% concentrated hydrochloric acid and 99% ethanol, reflux to remove the template CTAC, and obtain mesoporous organic silica nanoparticles.

[0020] Example 2 This example provides a method for reducing the size of mesoporous organic silica nanoparticles to 130 nm, comprising the following steps: (1) Dissolve 2.4 mL of CTAC in 40 mL of ultrapure water in a 100 mL round-bottom flask and stir at room temperature (15 min, 800 rpm); (2) After the oil bath is heated to 90°C, 15 μL of ethanolamine is slowly added dropwise using a pipette and stirred for 0.5 h. (3) Slowly add 1 mL of TEOS and stir at 90°C for 1 h; (4) Mix 1 mL of BTESPD and 3 mL of TEOS, slowly add the mixture to the reaction solution in step (3) using a rubber-tipped pipette, and react at 90°C for 3 h. (5) After the reaction in step (4) is completed, filter and wash the product with ethanol three times; then mix 1% concentrated hydrochloric acid and 99% ethanol, reflux to remove the template CTAC, and obtain mesoporous organic silica nanoparticles.

[0021] Example 3 This example provides a method for producing 70 nm mesoporous organic silica nanoparticles, comprising the following steps: (1) Dissolve 2.4 mL of CTAC in 40 mL of ultrapure water in a 100 mL round-bottom flask and stir at room temperature (15 min, 800 rpm); (2) After the oil bath is heated to 90 °C, 75 μL of triethanolamine is slowly added dropwise using a pipette and stirred for 0.5 h; (3) Slowly add 1 mL of TEOS and stir at 90°C for 1 h; (4) Mix 1 mL of BTESPD and 3 mL of TEOS, slowly add the mixture to the reaction solution in step (3) using a rubber-tipped pipette, and react at 90°C for 3 h. (5) After the reaction in step (4) is completed, filter and wash the product with ethanol three times; then mix 1% concentrated hydrochloric acid and 99% ethanol, reflux to remove the template CTAC, and obtain mesoporous organic silica nanoparticles.

[0022] Example 4 This example provides a method for producing 60nm mesoporous organic silica nanoparticles, which specifically includes the following steps: (1) Dissolve 2.4 mL of CTAC in 40 mL of ultrapure water in a 100 mL round-bottom flask and stir at room temperature (15 min, 800 rpm); (2) After the oil bath is heated to 90 °C, 150 μL of triethanolamine is slowly added dropwise using a pipette and stirred for 0.5 h; (3) Slowly add 1 mL of TEOS and stir at 90°C for 1 h; (4) Mix 1 mL of BTESPD and 3 mL of TEOS, slowly add the mixture to the reaction solution in step (3) using a rubber-tipped pipette, and react at 90°C for 3 h. (5) After the reaction in step (4) is completed, filter and wash the product with ethanol three times; then mix 1% concentrated hydrochloric acid and 99% ethanol, reflux to remove the template CTAC, and obtain mesoporous organic silica nanoparticles.

[0023] Example 5 This example provides a method for producing 40 nm mesoporous organic silica nanoparticles, which specifically includes the following steps: (1) Dissolve 2.4 mL of CTAC in 40 mL of ultrapure water in a 100 mL round-bottom flask and stir at room temperature (15 min, 800 rpm); (2) After the oil bath is heated to 90 °C, 300 μL of triethanolamine is slowly added dropwise using a pipette and stirred for 0.5 h; (3) Slowly add 1 mL of TEOS and stir at 90°C for 1 h; (4) Mix 1 mL of BTESPD and 3 mL of TEOS, slowly add the mixture to the reaction solution in step (3) using a rubber-tipped pipette, and react at 90°C for 3 h. (5) After the reaction in step (4) is completed, filter and wash the product with ethanol three times; then mix 1% concentrated hydrochloric acid and 99% ethanol, reflux to remove the template CTAC, and obtain mesoporous organic silica nanoparticles.

[0024] The following tests were performed on the mesoporous organic silica nanoparticles prepared in each example: 1. Morphology analysis.

[0025] Figure 1 A is the SEM and TEM images of the mesoporous organic silica nanoparticles prepared in Example 1. Figure 1 It can be seen that the mesoporous organic silica nanoparticles are uniform in size, with an average particle size of 99 nm.

[0026] Figure 1 B, 1C, 1D, 1E are SEM images of mesoporous organic silica nanoparticles prepared in Examples 2, 3, 4, and 5. Figure 2 It can be seen that the sizes of the mesoporous organic silica nanoparticles prepared in Examples 2, 3, 4, and 5 are 130 nm, 70 nm, 60 nm, and 40 nm, respectively.

[0027] 2. Pore size analysis.

[0028] Figure 2 The pore size distribution diagram of the mesoporous organic silica nanoparticles prepared in Example 1 is shown in FIG. Figure 2 It can be seen that the average pore size of mesoporous organic silica nanoparticles is 2.49 nm.

[0029] 3. Analysis of the linear relationship between particle size and triethanolamine dosage.

[0030] According to the particle size of the mesoporous organic silica nanoparticles prepared in each example and the amount of triethanolamine used, a linear relationship between the two was obtained by fitting, as shown in FIG. Figure 3 As shown in the following formula, R 2 is 0.985.

[0031]

[0032] Wherein, y is the particle size of mesoporous organic silica nanoparticles (in nm), and x is the amount of triethanolamine used (in μL).

[0033] Comparative Example 1 Different from Example 1, this example combines steps (3) and (4) in the example into one step, that is, 4 mL TEOS and 1 mL BTESPD are mixed and then added in one step. Figure 4 As shown in A, after combining steps (3) and (4) into one step, mesoporous organic silica nanoparticles with relatively uniform particle size cannot be synthesized.

[0034] Comparative Example 2 The difference from Example 1 is that the triethanolamine in step (2) is replaced by sodium hydroxide. Figure 4 As shown in Figure B, when triethanolamine is replaced with sodium hydroxide, mesoporous organic silica nanoparticles with uniform particle size cannot be synthesized.

[0035] In summary, the method of the present invention can achieve the regulation of the size of mesoporous organic silica nanoparticles in the range of 40-130 nm by regulating the content of triethanolamine in the reaction system. Moreover, the preparation method is simple, the prepared product has uniform morphology and particle size, and has the potential for large-scale preparation.

[0036] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the present invention, other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A method for regulating the size of mesoporous organic silica nanoparticles, characterized in that: The size of the product mesoporous organic silica nanoparticles is regulated by controlling the dosage of triethanolamine, and the method comprises the following steps: S1, after adding triethanolamine dropwise to the aqueous solution in which the template is dissolved, TEOS is added dropwise and stirred for reaction; S2, adding a mixture of BTESPD and TEOS dropwise to the reaction product of step S1 and stirring to react; S3, washing the product obtained in step S2, and then removing the template in the product to obtain mesoporous organic silica nanoparticles.

2. The method according to claim 1, characterized in that The particle size of the mesoporous organic silica nanoparticles is 40-130 nm.

3. The method according to claim 2, characterized in that The volume ratio of the TEOS in step S1 to the mixture in step S3 is 1:4, and in the mixture, the volume ratio of BTESPD to TEOS is 1:

3.

4. The method according to claim 3, characterized in that Determine the dosage of triethanolamine in step S1 according to the following formula: Wherein, y is the particle size of the mesoporous organic silica nanoparticles, and x is the amount of triethanolamine used.

5. The method according to claim 2, characterized in that In steps S1 and S2, the reaction temperature is 50-100°C.

6. The method according to claim 5, characterized in that In step S1, the reaction time is 0.5-1.5 h.

7. The method according to claim 5, characterized in that In step S2, the reaction time is 2-4 h.

8. The method according to claim 1, characterized in that In step S3, ethanol is used for the washing.

9. The method according to claim 1, characterized in that The template is any one of CTAC, CTAB, DTAC, TTAC, STAC, DDAC, BDAC, and CPC.

10. The method according to claim 9, characterized in that In step S3, the template is removed by refluxing with 1% concentrated hydrochloric acid and 99% ethanol.

Images