A method for preparing mesoporous titanium dioxide nanoparticles by two-step instantaneous nanometer precipitation technology

Abstract

The application discloses a method for preparing mesoporous titanium dioxide nanoparticles by two-step instantaneous nanometer precipitation technology. The method comprises the following steps: taking a cetyltrimethylammonium chloride aqueous solution as a No. 1 and No. 2 liquid stream; taking a tetrabutyl titanate ethanol solution as a No. 3 and No. 4 liquid stream, rapidly mixing and colliding the No. 1 to No. 4 liquid streams in a first mixing device to obtain a No. 5 liquid stream; taking deionized water as a No. 6 liquid stream, taking a PEG silane aqueous solution as a No. 7 and No. 8 liquid stream, rapidly mixing and colliding the No. 5 to No. 8 liquid streams in a second mixing device to obtain a nanoparticle suspension, and obtaining the mesoporous titanium dioxide nanoparticles by calcining. The technical scheme of the application can realize rapid and controllable preparation of mesoporous titanium dioxide nanoparticles, and has the advantages of small batch difference, short time consumption, easy industrial amplification and the like, and has a wide application prospect in the fields of energy application, biological medicine and the like.

Description

Technical Field

[0001] This invention relates to a technique for preparing mesoporous nanomaterial systems, and more particularly to a method for preparing mesoporous titanium dioxide nanoparticles using a two-step instantaneous nanoprecipitation technique. Background Technology

[0002] Titanium dioxide (TiO2) is a well-established material. In recent decades, its low cost, excellent chemical stability, environmental friendliness, and biocompatibility have attracted widespread attention. TiO2 has a wide range of applications, including degrading organic waste in water and air, serving as a sunscreen against UV damage, manufacturing solar cells, and killing bacteria through light irradiation. Compared to traditional TiO2 nanoparticles, mesoporous titanium dioxide nanoparticles (MTNs) have a higher specific surface area and larger pore volume, which is more conducive to the diffusion of reactants and products, as well as adsorption and catalysis.

[0003] Traditional methods for preparing mesoporous titanium dioxide nanoparticles mainly involve the sol-gel method. However, this method has drawbacks such as long preparation time and uneven nanoparticle size distribution. Since its introduction in 2003, the transient nanoprecipitation method has been widely used in biomedical, catalytic, and energy fields, due to its controllable nanoparticle size, small batch-to-batch variation, and short preparation cycle.

[0004] However, existing technologies for preparing mesoporous titanium dioxide nanoparticles are time-consuming and difficult to control the size of the nanoparticles. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a method for preparing mesoporous titanium dioxide nanoparticles using a two-step instantaneous nanoprecipitation technique, so as to achieve controllable particle size, rapid and large-scale preparation of mesoporous titanium dioxide nanoparticles.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A method for preparing mesoporous titanium dioxide nanoparticles using a two-step instantaneous nanoprecipitation technique includes the following steps:

[0008] (1) The aqueous solution of hexadecyltrimethylammonium chloride is used as liquid stream 1 and liquid stream 2; the tetrabutyl titanate ethanol solution is used as liquid stream 3 and liquid stream 4. Liquid streams 1 to 4 are rapidly mixed and collided in the first mixing device to obtain liquid stream 5.

[0009] (2) Deionized water was used as liquid stream No. 6, and PEG silane aqueous solution was used as liquid stream No. 7 and No. 8. Liquid stream No. 5 to No. 8 were rapidly mixed and collided in the second mixing device to obtain a nanoparticle suspension. After calcination, mesoporous titanium dioxide nanoparticles were obtained.

[0010] Furthermore, the concentration of hexadecyltrimethylammonium chloride in liquid streams 1 and 2 in step (1) is 0.2 mmol / mL.

[0011] Furthermore, the pH of liquid streams 1 and 2 in step (1) is 5 to 10; even further, the pH of liquid streams 1 and 2 is 8.

[0012] Further, the concentration of tetrabutyl titanate in liquid streams 3 and 4 in step (1) is 0.15 to 0.5 mmol / mL; even further, the concentration of tetrabutyl titanate in liquid streams 3 and 4 is 0.3 mmol / mL.

[0013] Furthermore, in step (1), the flow rate ratio of liquid flow No. 3 and No. 4 to liquid flow No. 1 and No. 2 is 1:1 to 5; even further, the flow rate ratio of liquid flow No. 3 and No. 4 to liquid flow No. 1 and No. 2 is 1:5.

[0014] Further, the concentration of PEG silane in liquid streams 7 and 8 in step (2) is 0.01 to 0.3 mmol / mL; even further, the concentration of PEG silane in liquid streams 7 and 8 is 0.15 mmol / mL.

[0015] Furthermore, the flow rate of liquid streams 5 to 8 in step (2) is 30 mL / min.

[0016] Furthermore, the calcination is carried out at 500°C for 4 hours.

[0017] The present invention has the following advantages and effects compared with the prior art:

[0018] (1) The technical solution of the present invention is based on instantaneous nanoprecipitation technology. By introducing the end-capping agent PEG silane to prevent the growth of titanium nanoparticles, mesoporous titanium dioxide nanoparticles can be prepared rapidly and efficiently.

[0019] (2) This invention utilizes a two-step instantaneous nanoprecipitation method to prepare mesoporous titanium dioxide nanoparticles, which greatly shortens the preparation time and effectively controls the size of the mesoporous titanium dioxide nanoparticles, resulting in small batch-to-batch variations and easy industrial scale-up. This method is simple to operate, easy to control, and has broad development prospects and research value. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the experimental apparatus used to prepare mesoporous titanium dioxide nanoparticles in the embodiments;

[0021] Figure 2 This is a particle size distribution diagram of the mesoporous titanium dioxide nanoparticles in Example 6;

[0022] Figure 3 This is a transmission electron microscope image of the mesoporous titanium dioxide nanoparticles in Example 6;

[0023] Figure 4 This is a nitrogen adsorption-desorption curve of the mesoporous titanium dioxide nanoparticles in Example 6;

[0024] Figure 5 This is a pore size distribution diagram of the mesoporous titanium dioxide nanoparticles in Example 6;

[0025] Figure 6 This is a graph showing the particle size change of the mesoporous titanium dioxide nanoparticles in Example 6 over 14 days at room temperature. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0027] Example 1

[0028] In the first mixing apparatus, cetyltrimethylammonium chloride was dissolved in deionized water at a concentration of 0.2 mmol / mL, serving as streams 1 and 2, with a pH of 5; tetrabutyl titanate was dissolved in anhydrous ethanol at a concentration of 0.15 mmol / mL, serving as streams 3 and 4. Two syringe pumps controlled the flow rates of streams 1 and 2, and streams 3 and 4, respectively. The flow rates of streams 1 and 2 were set to 10 mL / min, and the flow rates of streams 3 and 4 were also set to 10 mL / min. All four streams entered a four-channel vortex mixer simultaneously for rapid mixing, and stream 5 was collected. In the second mixing apparatus, stream 6 was deionized water; PEG silane was dissolved in deionized water at a concentration of 0.3 mmol / mL, serving as streams 7 and 8. Two syringe pumps controlled the flow rates of liquid streams 5 and 6, and liquid streams 7 and 8, respectively, all at a rate of 30 mL / min. The four streams flowed simultaneously into the four-channel vortex mixer. After the solution flow stabilized, the prepared nanoparticle suspension was collected at the outlet. The obtained nanoparticles were then calcined at 500°C for 4 hours to obtain mesoporous titanium dioxide nanoparticles. A schematic diagram of the apparatus and liquid flow is shown below. Figure 1 As shown.

[0029] The mesoporous titanium dioxide nanoparticles prepared in this embodiment were characterized and analyzed. The particle size of the mesoporous titanium dioxide nanoparticles prepared in this embodiment is about 200 nm.

[0030] Example 2

[0031] In the first mixing apparatus, cetyltrimethylammonium chloride was dissolved in deionized water at a concentration of 0.2 mmol / mL, serving as streams 1 and 2, with a pH of 5; tetrabutyl titanate was dissolved in anhydrous ethanol at a concentration of 0.3 mmol / mL, serving as streams 3 and 4. Two syringe pumps controlled the flow rates of streams 1 and 2, and streams 3 and 4, respectively. The flow rates of streams 1 and 2 were set to 10 mL / min, and the flow rates of streams 3 and 4 were also set to 10 mL / min. All four streams entered a four-channel vortex mixer simultaneously for rapid mixing, and stream 5 was collected. In the second mixing apparatus, stream 6 was deionized water; PEG silane was dissolved in deionized water at a concentration of 0.3 mmol / mL, serving as streams 7 and 8. Two injection pumps control the flow rates of liquid streams 5 and 6 and liquid streams 7 and 8 respectively, all at a flow rate of 30 mL / min. The four liquid streams flow into the four-channel vortex mixer simultaneously. After the solution flow out is stable, the prepared nanoparticle suspension is collected at the outlet. The obtained nanoparticles are calcined at 500℃ for 4 hours to obtain mesoporous titanium dioxide nanoparticles.

[0032] The mesoporous titanium dioxide nanoparticles prepared in this embodiment were characterized and analyzed. The particle size of the mesoporous titanium dioxide nanoparticles prepared in this embodiment is about 340 nm.

[0033] Example 3

[0034] In the first mixing apparatus, hexadecyltrimethylammonium chloride was dissolved in deionized water at a concentration of 0.2 mmol / mL, serving as streams 1 and 2, with a pH of 8; tetrabutyl titanate was dissolved in anhydrous ethanol at a concentration of 0.3 mmol / mL, serving as streams 3 and 4. Two syringe pumps controlled the flow rates of streams 1 and 2, and streams 3 and 4, respectively. The flow rates of streams 1 and 2 were set to 10 mL / min, and the flow rates of streams 3 and 4 were also set to 10 mL / min. All four streams entered a four-channel vortex mixer simultaneously for rapid mixing, and stream 5 was collected. In the second mixing apparatus, stream 6 was deionized water; PEG silane was dissolved in deionized water at a concentration of 0.3 mmol / mL, serving as streams 7 and 8. Two injection pumps control the flow rates of liquid streams 5 and 6 and liquid streams 7 and 8 respectively, all at a flow rate of 30 mL / min. The four liquid streams flow into the four-channel vortex mixer simultaneously. After the solution flow out is stable, the prepared nanoparticle suspension is collected at the outlet. The obtained nanoparticles are calcined at 500℃ for 4 hours to obtain mesoporous titanium dioxide nanoparticles.

[0035] The mesoporous titanium dioxide nanoparticles prepared in this embodiment were characterized and analyzed. The particle size of the mesoporous titanium dioxide nanoparticles prepared in this embodiment is about 220 nm.

[0036] Example 4

[0037] In the first mixing apparatus, hexadecyltrimethylammonium chloride was dissolved in deionized water at a concentration of 0.2 mmol / mL, serving as streams 1 and 2, with a pH of 8; tetrabutyl titanate was dissolved in anhydrous ethanol at a concentration of 0.3 mmol / mL, serving as streams 3 and 4. Two syringe pumps controlled the flow rates of streams 1 and 2, and streams 3 and 4, respectively. The flow rates of streams 1 and 2 were set to 10 mL / min, and the flow rates of streams 3 and 4 were also set to 10 mL / min. All four streams entered a four-channel vortex mixer simultaneously for rapid mixing, and stream 5 was collected. In the second mixing apparatus, stream 6 was deionized water; PEG silane was dissolved in deionized water at a concentration of 0.3 mmol / mL, serving as streams 7 and 8. Two injection pumps control the flow rates of liquid streams 5 and 6 and liquid streams 7 and 8 respectively, all at a flow rate of 30 mL / min. The four liquid streams flow into the four-channel vortex mixer simultaneously. After the solution flow out is stable, the prepared nanoparticle suspension is collected at the outlet. The obtained nanoparticles are calcined at 500℃ for 4 hours to obtain mesoporous titanium dioxide nanoparticles.

[0038] The mesoporous titanium dioxide nanoparticles prepared in this embodiment were characterized and analyzed. The particle size of the mesoporous titanium dioxide nanoparticles prepared in this embodiment is about 150 nm.

[0039] Example 5

[0040] In the first mixing apparatus, cetyltrimethylammonium chloride was dissolved in deionized water at a concentration of 0.2 mmol / mL, serving as streams 1 and 2, with a pH of 8; tetrabutyl titanate was dissolved in anhydrous ethanol at a concentration of 0.3 mmol / mL, serving as streams 3 and 4. Two syringe pumps controlled the flow rates of streams 1 and 2 and streams 3 and 4, respectively. The flow rates of streams 1 and 2 were set to 50 mL / min, and the flow rates of streams 3 and 4 were set to 10 mL / min. The four streams simultaneously entered a four-channel vortex mixer for rapid mixing, and stream 5 was collected. In the second mixing apparatus, stream 6 was deionized water; PEG silane was dissolved in deionized water at a concentration of 0.3 mmol / mL, serving as streams 7 and 8. Two syringe pumps controlled the flow rates of liquid streams 5 and 6, and liquid streams 7 and 8, respectively, all at a flow rate of 30 mL / min. The four liquid streams flowed simultaneously into the four-channel vortex mixer. After the solution flowed out and stabilized, the prepared nanoparticle suspension was collected at the outlet. The obtained nanoparticles were calcined at 500°C for 4 hours to obtain mesoporous titanium dioxide nanoparticles. The mesoporous titanium dioxide nanoparticles prepared in this embodiment were characterized and analyzed. The particle size of the mesoporous titanium dioxide nanoparticles prepared in this embodiment was approximately 100 nm.

[0041] Example 6

[0042] In the first mixing apparatus, cetyltrimethylammonium chloride was dissolved in deionized water at a concentration of 0.2 mmol / mL, serving as streams 1 and 2, with a pH of 8; tetrabutyl titanate was dissolved in anhydrous ethanol at a concentration of 0.3 mmol / mL, serving as streams 3 and 4. Two syringe pumps controlled the flow rates of streams 1 and 2 and streams 3 and 4, respectively. The flow rates of streams 1 and 2 were set to 50 mL / min, and the flow rates of streams 3 and 4 were set to 10 mL / min. The four streams simultaneously entered a four-channel vortex mixer for rapid mixing, and stream 5 was collected. In the second mixing apparatus, stream 6 was deionized water; PEG silane was dissolved in deionized water at a concentration of 0.15 mmol / mL, serving as streams 7 and 8. Two injection pumps control the flow rates of liquid streams 5 and 6 and liquid streams 7 and 8 respectively, all at a flow rate of 30 mL / min. The four liquid streams flow into the four-channel vortex mixer simultaneously. After the solution flow out is stable, the prepared nanoparticle suspension is collected at the outlet. The obtained nanoparticles are calcined at 500℃ for 4 hours to obtain mesoporous titanium dioxide nanoparticles.

[0043] The mesoporous titanium dioxide nanoparticles prepared in this embodiment were characterized and analyzed. The particle size of the mesoporous titanium dioxide nanoparticles prepared in this embodiment is approximately 35 nm, and the particle size distribution is as follows: Figure 2 As shown. The morphology of the particles is as follows. Figure 3 As shown. The nanoparticles have a mesoporous structure, and their nitrogen adsorption-desorption curves are shown in the figure. Figure 4 As shown, its aperture distribution is as follows Figure 5 As shown in the figure. The mesoporous titanium dioxide nanoparticles exhibit good stability. The particle size change of the mesoporous titanium dioxide nanoparticles over 14 days at room temperature is shown in the figure. Figure 6 As shown.

[0044] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing mesoporous titanium dioxide nanoparticles using a two-step instantaneous nanoprecipitation technique, characterized in that, The method comprises the following steps: (1) an aqueous solution of cetyltrimethylammonium chloride as No. 1 and No. 2 liquid streams; an ethanol solution of tetrabutyl titanate as No. 3 and No. 4 liquid streams, the No. 1 to No. 4 liquid streams are rapidly mixed and collided in a first mixing device to obtain a No. 5 liquid stream; (2) deionized water as No. 6 liquid stream; an aqueous solution of PEG silane as No. 7 and No. 8 liquid streams, the No. 5 to No. 8 liquid streams are rapidly mixed and collided in a second mixing device to obtain a nanoparticle suspension, and mesoporous titanium dioxide nanoparticles are obtained after calcination.

2. The method of claim 1, wherein: the concentration of cetyltrimethylammonium chloride in the No. 1 and No. 2 liquid streams in step (1) is 0.2 mmol / mL; the pH of the No. 1 and No. 2 liquid streams in step (1) is 5-10; the concentration of tetrabutyl titanate in the No. 3 and No. 4 liquid streams in step (1) is 0.15-0.5 mmol / mL; the flow rate ratio of the No. 3 and No. 4 liquid streams to the No. 1 and No. 2 liquid streams in step (1) is 1:1-5.

3. The method of claim 2, wherein: the pH of the No. 1 and No. 2 liquid streams in step (1) is 8; the concentration of tetrabutyl titanate in the No. 3 and No. 4 liquid streams in step (1) is 0.3 mmol / mL; the flow rate ratio of the No. 3 and No. 4 liquid streams to the No. 1 and No. 2 liquid streams in step (1) is 1:

5.

4. The method of claim 1, wherein: the flow rate of the No. 5 to No. 8 liquid streams in step (2) is 30 mL / min; the concentration of PEG silane in the No. 7 and No. 8 liquid streams in step (2) is 0.01-0.3 mmol / mL.

5. The method of claim 4, wherein: the concentration of PEG silane in the No. 7 and No. 8 liquid streams in step (2) is 0.15 mmol / mL.

6. The method of claim 1, wherein: the calcination is at 500℃ for 4 hours.

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