CN110203935A - Tube wall is in the right-handed helix nano-tube material and preparation method for radiating hole arrangement - Google Patents

Abstract

The invention discloses a right-handed helical silicon nanotube material with a tube wall arranged in radial holes and a preparation method, and belongs to the technical field of nanomaterials. The silicon nanotube material is composed of more than one silicon nanotubes with a length of 100nm-20μm and a diameter of 3nm-100nm arranged in space, and each silicon nanotube is a hollow cavity with one end open and the other end closed. , there are more than one channel distributed on the side wall of the hollow cavity, each channel is a radial channel radiating from the center to the edge, and its average diameter is 2nm-50nm. The specific surface area of the chiral silicon nanotubes reaches 600-1400 m ² /g, which can be used as nanocarriers for drugs, proteins and genes for in vivo treatment. At the same time, the chiral nanotubes with this structure can be further assembled and used in Chiral catalysis and resolution.

Description

Right-handed helical silicon nanotube material with tube wall arranged in radial holes and preparation method

technical field

The invention relates to mesoporous silica, belongs to the technical field of nanomaterials, and in particular relates to a right-handed helical silicon nanotube material whose tube walls are arranged in radial holes and a preparation method.

Background technique

Since Mobile successfully prepared MCM-41 series mesoporous silica, mesoporous materials have been widely used in carriers due to their unique and uniform pore structure, large specific surface area and pore volume, controllable pore size and easy-to-modify surface structure. , adsorption, separation and catalysis, semiconductor materials and optoelectronic devices and sensor and regulator arrays and other fields. However, traditional disordered mesoporous silica spheres face a series of difficulties such as low adsorption capacity and low catalytic activity, so the preparation of silica materials with ordered mesoporous channel structure has important research value and potential application prospects. At present, controllable morphology, structure and pore size have become one of the challenges in the preparation of silica nanomaterials, especially the preparation of silica materials with radially ordered mesoporous channel structures has become a research hotspot for many researchers.

For example, Moon et al. successfully prepared mesoporous silica spheres with ordered radioactive channels distribution using a bicontinuous microemulsion system as a template (Moon D, Lee J, Langmuir, 2012, 28, 12341-12347). Peng et al. used a microemulsion system composed of CTAB-1,3,5-trimethylbenzene-ethanol-water as a template and TEOS as a silicon source to prepare silica spheres with a core-shell structure, with a local hexagonal arrangement in the core center. The worm-like mesopores have radially ordered mesoporous channels on the shell, but the pore size is small (3-7.3 nm). The core-shell SiO ₂ spheres have high specific surface area (745-912 m ² /g) and pore volume (0.98-1.34 cm ³ /g), and the results prove that this silica material has a secondary pore structure It is expected to be applied in the fields of biocatalysis and adsorption (PengJ, LiuJ, LiuJ, J.Mater.Chem.A, 2014, 2, 8118-8125).

The Chinese invention patent application (application publication number CN102849750A, application publication date 2013-01-02) discloses a radial channel mesoporous silica and a preparation method thereof. It is characterized in that the product SiO ₂ material has a spherical morphology, a smooth surface, a particle size of 700-1000 nm, and the channels are radial channels radiating from the center to the edge. surface area and pore volume. The specific preparation method is to use water-ethanol-diethyl ether as a co-solvent and cetyltrimethylammonium bromide (CTAB) or cetyltrimethylammonium chloride (CTAC) as a template at room temperature, Ammonia is used as a catalyst to promote the hydrolysis and polycondensation of silicon source (TEOS). A certain proportion of silane coupling agent (N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane) must be added to the synthesis system of the present invention, and the material composition of the reaction system is strictly required.

Chinese invention patent application (application publication number CN104129791A, application publication date 2014-11-05) discloses a spherical silica material with radial mesoporous channel structure and a preparation method thereof. It is characterized in that the invention utilizes the oil-in-water microemulsion system formed by CTAB, PVP-ethanol-cyclohexane-water as a template, and the silicon source TEOS is hydrolyzed and polycondensed on the surface of the microemulsion drop sphere, and self-assembled to synthesize a radial medium. Pore-channel _- structured spherical mesoporous SiO nanomaterials. The mesoporous silica is monodisperse spherical, with a particle size range of 350-650 nm, a specific surface area of 975-1114 m ² /g, a pore size of 3.9-4.1 nm, and mesoporous channels radiating from the center of the sphere to the edge of the sphere.

However, the mesoporous _SiO2 nanomaterials prepared above all exhibit spherical shape.

At the same time, as a common phenomenon in nature, chirality exists widely in many substances in nature. Studies have shown that life activities are closely related to the chirality of biomolecules. However, in the field of organic chemistry research, chiral small molecule catalysts Faced with expensive, and difficult to recycle and reuse problems.

The research group of Prof. Yonggang Yang of Soochow University has reported the use of amino acid derivatives to control the morphology and pore structure of silica, and to realize the chirality control of the organic-inorganic hybrid silica structure at the molecular scale. For example, using the self-assembly of amino acid derivatives as a template, silica nanospheres, silica nanotubes with spring-like pores inside, silica nanoparticles with layered mesopores on the surface and cylindrical pores on the inside, and The pipes are silica nanotubes in which the internal pores of the helical structure are chiral arranged, and the like.

However, there is no report on right-handed helical silicon nanotubes with radial pores arranged on the tube wall.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention provides a right-handed helical silicon nanotube material whose tube wall is arranged with radial holes. Arranged in space, each of the silicon nanotubes is a hollow cavity with one end open and the other end closed, and more than one channel is distributed on the side wall of the hollow cavity, and each of the channels is from the center to the center. The radial channel with edge radiation has an average pore diameter of 2nm to 50nm.

Specifically, the silicon nanotubes are arranged disorderly in three-dimensional space, but they have a right-handed helical structure as a whole.

Preferably, the length of the silicon nanotube is 500nm˜600nm.

Preferably, the length of the silicon nanotube is 600nm˜700nm.

Preferably, the length of the silicon nanotube is 700nm˜800nm.

Preferably, the length of the silicon nanotube is 800nm˜900nm.

Preferably, the length of the silicon nanotube is 900 nm˜1000 nm.

Preferably, the length of the silicon nanotube is 900 nm˜1000 nm.

Preferably, the length of the silicon nanotube is 1000 nm˜10000 nm.

Preferably, the length of the silicon nanotube is 10,000 nm to 12,000 nm.

Preferably, the length of the silicon nanotube is 12000nm˜2000nm.

Preferably, the diameter of the silicon nanotube is 5 nm˜90 nm.

Preferably, the diameter of the silicon nanotube is 10 nm˜70 nm.

Preferably, the diameter of the silicon nanotube is 30 nm˜60 nm.

Preferably, the diameter of the silicon nanotube is 40 nm˜50 nm.

Preferably, the radial pores have an average pore diameter of 2 nm to 40 nm.

Preferably, the radial pores have an average pore diameter of 5 nm to 30 nm.

Optimally, the average pore diameter of the radial channels is 15 nm.

Further, the specific surface area of the silicon nanotube material is 600-1400 m ² /g.

Preferably, the specific surface area of the silicon nanotube material is 700-1200 m ² /g.

Optimally, the specific surface area of the silicon nanotube material is 800 m ² /g.

Optimally, the specific surface area of the silicon nanotube material is 1000 m ² /g.

In order to better achieve the technical purpose of the present invention, the present invention also discloses a preparation method of the above-mentioned right-handed helical silicon nanotube material whose tube wall is arranged with radial holes, which comprises using cationic colloid as template agent and silicate as silicon source , and the chiral silicon nanotubes with the channels in the tube wall arranged radially were prepared. Further, the cationic colloid includes a compound having the following structural formula:

Wherein, m=2～18, n=2～20; R is CH ₃ -, (CH ₃ ) ₂ CH-, (CH ₃ ) ₂ CH ₂ H- or Ph-CH ₂ -.

Preferably, if m=10, n=16, and R is CH ₃ -, the cationic colloid has the following specific chemical structural formula,

Specifically, the cationic colloid with the above chemical structural formula is prepared by using L-alanine as a reaction raw material, and sequentially undergoing BOC protection, amidation, de-BOC protection, amidation, and substitution of pyridine and hexafluorophosphate for bromine salt.

Specifically, the synthetic route is as follows:

Further, the preparation method includes the following specific processes:

1) adding the cationic colloid into deionized water to prepare an aqueous cationic solution;

Preferably, the concentration of the cationic aqueous solution is 10-50 mg/mL.

Preferably, the stirring speed in step 1) is controlled to be 100-1500 rpm, and the stirring is carried out for 1 s-100 min.

2) adding an alkali solution and an alkyl alcohol to the cationic aqueous solution obtained in step 1), adjusting the pH of the solution to 7.5-14, and stirring for 1 s-100 min to obtain a mixed solution;

Preferably, the stirring speed in step 2) is controlled to be 100-1500 rpm, and the stirring is carried out for 1 s-100 min.

3) Adding silicate to the mixed solution prepared in step 2), the reaction produces a white colloid, and then washing and calcining to obtain a right-handed helical silicon nanotube material whose tube wall is arranged with radial pores.

Preferably, in step 2), ethanol and hydrochloric acid are used for washing at least once respectively.

Further, the volume ratio of the alkaline solution to the alkyl alcohol described in step 2) is 9:1 to 8:2.

Further, in step 2), the alkaline solution includes one or more of tetramethylammonium hydroxide, ammonia water, sodium hydroxide or potassium hydroxide to configure the obtained solution.

Preferably, the mass percentage concentration of the concentrated ammonia water is 20-25%.

Preferably, the molar concentration of the sodium hydroxide is 1-5M/L.

Preferably, the molar concentration of the sodium hydroxide is 1-5M/L.

Preferably, the mass percentage concentration of the tetramethylammonium hydroxide is 1-25%.

Further, the alkyl alcohol in step 2) includes at least one of ethanol, n-propanol, isopropanol, n-butanol or isobutanol.

Preferably, the alkyl alcohol is isopropanol.

Preferably, in step 3), the reaction temperature is controlled to be 0-20° C., and the reaction time is 1-10 h.

Further, the silicates described in step 3) include tetraethyl orthosilicate, tetramethyl orthosilicate, 1,2-bis(triethoxysilyl)ethylene, 1,2-bis(triethoxysilane) at least one of silyl)benzene or 1,4-bis(triethoxysilyl)benzene.

Preferably, the silicate accounts for 0.5-5% of the volume of the reaction system.

Further, the calcination conditions described in step 3) are, the temperature is controlled at 500-600° C., and the calcination is performed for 4-8 hours.

Preferably, the temperature is controlled at 550° C. and calcined for 5 hours, so that the pores of the target material are relatively uniform.

The beneficial effects of the present invention are as follows:

The invention provides a cationic colloid as a template, and the right-handed helical silicon nanotube material whose tube wall is arranged with radial holes is successfully prepared. The preparation method is simple, and the prepared nanotube material has a specific surface area of 600-1400 m ² /g. The diameter of the radiation pores on the surface is 2nm to 50nm. The nanotube material can be used as a nanocarrier for drugs, proteins and genes for in vivo treatment. At the same time, the chiral nanotubes with this structure can be further assembled and used for chiral catalysis. and split areas.

Description of drawings

Fig. 1 is the transmission electron microscope picture of embodiment 2 of the present invention before removing template of silicon nanomaterial;

Fig. 2 is the transmission electron microscope picture of the silicon nanotube material of embodiment 2 of the present invention;

Fig. 3 is a transmission electron microscope image of the silicon nanotube material of Fig. 2 after magnification;

Fig. 4 is the scanning electron microscope image of the silicon nanotube material of Fig. 2;

5 is a scanning electron microscope image of a silicon nanotube material in Example 3 of the present invention;

6 is a scanning electron microscope image of a silicon nanotube material in Example 4 of the present invention;

7 is a scanning electron microscope image of a silicon nanotube material in Example 4 of the present invention;

8 is a schematic diagram of the microscopic topography of the silicon nanotube material in Example 5 of the present invention;

9 is a schematic diagram of the microscopic topography of the silicon nanotube material in Example 5 of the present invention;

Fig. 10 is the radial distribution diagram of the surface pore channel of silicon nanomaterial obtained in implementation 2 of the present invention;

FIG. 11 is a test diagram of the adsorption-desorption test of the silicon nanomaterial prepared in Example 2 of the present invention to nitrogen.

Detailed ways

In order to better explain the present invention, the main content of the present invention is further illustrated below in conjunction with specific embodiments, but the content of the present invention is not limited to the following embodiments.

Example 1

This example discloses the preparation of cationic colloid L-16Ala11PyPF6, which is carried out by the synthetic route disclosed in the content of the present invention, and the intermediate product L-16Ala11PyBr is also a chiral small molecule template. Place in phosphate to complete ion exchange.

Example 2

This embodiment further discloses the preparation process of chiral silicon nanotubes, which is as follows:

Take 12 mg/mL of the L-16Ala11PyPF6 chiral small molecule template prepared in the above Example 1 and dissolve it in a mixed solution of concentrated ammonia water and n-propanol with a volume ratio of 8:2, control the reaction system below 20 ° C, and slowly add 20 μL of four Ethoxysilane, the reaction product obtained by continuing the reaction after the addition is a silicon nanotube material with a template. No pores were formed.

The template was then eluted with ethanol and concentrated hydrochloric acid, respectively, and then calcined in a muffle furnace at 550 °C for 5 h at a programmed temperature to obtain silicon nanotube materials with the structures shown in Figure 2, Figure 3 and Figure 4. It can be seen from Figure 2 that , the silicon nanomaterial prepared in the embodiment of the present invention is a silicon nanotube material, and several channels are uniformly formed on its surface, and the channels are radial channels radiating from the center to the edge, and the average pore diameter is 3-5nm. The specific surface area of the silicon nanotube material was further measured to be 950 m ² /g. Further referring to FIG. 3 and FIG. 4 , it can be known that the silicon nanotube material prepared in the embodiment of the present invention exhibits a right-handed helical structure.

Example 3

On the basis of the above-mentioned Example 2, other reaction conditions remained unchanged, and only the temperature of the reaction system was controlled at 25 ° C to complete the reaction, and the silica nanospheres shown in Figure 5 were obtained, and the temperature of the controlled reaction system was 25 °C Between ℃～90℃, the right-handed helical silicon nanotube material whose tube wall is arranged with radial pores cannot be obtained. This shows that the reaction temperature has a great influence on the structure of the silicon nanomaterial of the present invention.

Example 4

On the basis of the above Example 2, other reaction conditions remained unchanged, the volume ratio of concentrated ammonia water and n-propanol was adjusted to 7:3, and the reaction obtained the mixture of silica nanospheres and nanotubes shown in Figure 6 .

Similarly, on the basis of the above Example 2, other reaction conditions remained unchanged, the mass percentage concentration of concentrated ammonia water was diluted from 25% to 2.5% and the experiment was completed to obtain the amorphous structure shown in Figure 7. Silicon dioxide nanomaterials, and the concentration of concentrated ammonia water is controlled between 20 and 25%, and its structure will not change.

This shows that the amount of the reaction solvent, the concentration of the reaction solvent, etc. also have a relatively large influence on the structure of the silicon nanomaterial of the present invention.

Example 5

On the basis of the above Example 2, other reaction conditions remained unchanged, and the concentration of the chiral small molecule template L-16Ala11PyPF6 in the mixed solution was adjusted to 8 mg/mL, and the spherical silica nanomaterial shown in Figure 8 was obtained.

On the basis of the above Example 2, other reaction conditions remained unchanged, and the concentration of the chiral small molecule template L-16Ala11PyPF6 in the mixed solution was changed to 6 mg/mL, and the mixture of spherical and random structures as shown in Figure 9 was obtained. Silica nanomaterials.

This shows that the concentration of the chiral small molecule template has a great influence on the structure of the silicon nanomaterial of the present invention.

At the same time, if any one of 1,4-bis(triethoxysilyl)benzene was used to replace the silicon source tetraethoxysilane in the above Example 2, the structure of the obtained silicon nanomaterial remained unchanged. This shows that the silicon source has little effect on the structure of the silicon nanomaterial of the present invention.

In addition, if the small molecule template L-16Ala11PyPF6 of the present invention is replaced with L-16Ala11PyBr, the silicon nanotube material with the structure of the present invention will not be obtained.

For the right-handed helical silicon nanotube material with radial holes arranged in the tube wall prepared by the present invention, Figure 10 shows that the pore size distribution of the silicon nanotube material obtained in Example 2 of the present invention is about 4 nm, and Figure 11 shows that the curve is a typical IV type The adsorption curve shows that there is a mesoporous structure in the sample.

Therefore, the present invention provides a right-handed helical silicon nanotube material with cationic colloid as a template, and the tube wall is arranged with radial pores. The pore size of the surface radiation pores is 2-50 nm. The nanotube material can be used as a nanocarrier for drugs, proteins and genes for in vivo treatment. At the same time, the chiral nanotubes with this structure can be further assembled and used for chiral catalysis and Split, etc.

The above embodiments are only the best examples, and are not intended to limit the embodiments of the present invention. In addition to the above-described embodiments, the present invention has other embodiments. All technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (10)

1. a kind of tube wall in radiation hole arrangement right-handed helix nano-tube material, it by one or more length be 100nm~ 20 μm, nano-tube of the diameter between 3nm~100nm rearrange in space, the every nano-tube is opened for one end The hollow cavity that mouth, other end closing are arranged, is distributed with more than one duct, each hole on the side wall of hollow cavity Road is the radial duct from center to fringe radiation, and average pore size is 2nm~50nm.

2. the right-handed helix nano-tube material that tube wall is arranged in radiation hole according to claim 1, it is characterised in that: described The specific surface area of nano-tube material is 600~1400m²/g。

3. tube wall described in a kind of claim 1 is in the preparation method of the right-handed helix nano-tube material of radiation hole arrangement, it is wrapped It includes and uses cationic colloidal for template, using esters of silicon acis as silicon source, the chiral silicon that tube wall duct is arranged radially is prepared Nanotube.

4. preparation method of the tube wall in the right-handed helix nano-tube material of radiation hole arrangement according to claim 3, spy Sign is: the cationic colloidal includes the compound for having following structural formula:

Wherein, m=2~18, n=2~20；R is CH₃, (CH₃)₂CH-, (CH₃)₂CH₂H- or Ph-CH₂-。

5. according to the preparation method for the right-handed helix nano-tube material that the tube wall of claim 3 or 4 is arranged in radiation hole, Be characterized in that: the preparation method includes following detailed process:

1) cationic colloidal is added in deionized water, preparation obtains cationic aqueous solution；

2) aqueous slkali and alkylol are added into the cationic aqueous solution that step 1) obtains, adjustment solution ph is 7.5~14, is stirred It mixes to obtain mixed solution；

3) esters of silicon acis is added into mixed solution made from step 2), reaction generates white colloidal, then washed and calcining obtains The right-handed helix nano-tube material that tube wall is arranged in radiation hole.

6. preparation method of the tube wall in the right-handed helix nano-tube material of radiation hole arrangement according to claim 5, spy Sign is: the volume ratio of aqueous slkali described in step 2) and alkylol is 9:1~8:2.

7. preparation method of the tube wall in the right-handed helix nano-tube material of radiation hole arrangement according to claim 6, spy Sign is: aqueous slkali described in step 2) include one of tetramethylammonium hydroxide, ammonium hydroxide, sodium hydroxide or potassium hydroxide with Upper configuration acquired solution.

8. the preparation method for the right-handed helix nano-tube material that tube wall described according to claim 6 or 7 is arranged in radiation hole, Be characterized in that: alkylol described in step 2) includes at least one of ethyl alcohol, normal propyl alcohol, isopropanol, n-butanol or isobutanol.

9. preparation method of the tube wall in the right-handed helix nano-tube material of radiation hole arrangement according to claim 5, spy Sign is: esters of silicon acis described in step 3) includes tetraethyl orthosilicate, positive quanmethyl silicate, bis- (triethoxysilicane) second of 1,2- At least one of bis- (triethoxysilicane) benzene of alkene, 1,2- or bis- (triethoxy silicon substrate) benzene of 1,4-.

10. preparation method of the tube wall in the right-handed helix nano-tube material of radiation hole arrangement according to claim 5, spy Sign is: calcination condition described in step 3) is to control 500~600 DEG C of temperature, calcines 4~8h.