KR101091203B1 - Spiral silica nano tube and its making method in use of non-chiral cation gelator - Google Patents

Abstract

The present invention relates to a method for producing silica nanotubes simply and simply by using a simple and easily available achiral cationic gelling agent, instead of using a chiral cationic gelling agent prepared through a complicated process as in the prior art.

The present silica nanotube manufacturing method is a method for producing silica nanotubes having a spiral structure by using a mixed gelling agent of a chiral neutral gelling agent and a cationic gelling agent, wherein the cationic gelling agent is a non-chiral cationic gelling agent. It is done.

Preferably, the achiral cationic gelling agent is used dodecyltrimethylammonium bromide, and the chiral neutralizing gelling agent is a low molecular neutral gelling agent having an asymmetric carbon of diphenylethylenediamide.

In addition, the present invention provides a method that can adjust the degree of orientation and twist of the helical silica nanotubes according to the change in the optical purity of the neutral gelling agent.

Silica Nanotubes, Organic / Inorganic Composites

Description

Spiral silica nanotube using achiral cationic gelling agent and its preparation method {SPIRAL SILICA NANO TUBE AND ITS MAKING METHOD IN USE OF NON-CHIRAL CATION GELATOR}

The present invention relates to the production of silica nanotubes using a sol-gel reaction with an organogelling agent as a template, and more specifically, to a low molecular neutral gelling agent having an asymmetric carbon of diphenylethylenediamide, dode is a non-chiral compound. The present invention relates to the preparation of a chiral spiral silica nanotube using an organic gel prepared by mixing a cationic gelling agent of siltrimethylammonium bromide as a template.

Nanotubes and related nanostructures have become increasingly important with the development of science and technology over the last decade because of their potential applications as new materials and next-generation nanodevices.

In particular, nanotubes are of great interest in the field of new materials and materials science, because these structures can be applied to nanocatalysts, nanomagnetic recording media, hydrogen storage, separation of chemicals with stereochemistry, and sensors. Among them, based on Stober research, which produced monodisperse silica particles using TEOS (tetraethylorthosilicate), silicon alkoxide, inorganic precursor to polycondensate with organic substance, alcohol as solvent, ammonia as catalyst, and water for hydrolysis and polycondensation reaction. Many researchers have been interested in the production of nanotubes using sol-gel reactions as organogelling agents, which are self-assembled optical isomers.

In particular, organogels, which are used as templates for the production of silica nanotubes, can be applied to the products and foods used in everyday life and new biomedical medicines, and have received a lot of attention because of their potential for controlling the shape of nanotubes.

As a representative example, Yoza's research has synthesized α- and β-isomers derived from monosaccharides D-glucose, D-galactose and D-mannose based on the synthesis of hydrogenated gel bonds in various organic solvents. It has been reported that the gelation occurs by self-assembly and the solubility of the gelling agent and the degree of gelation change rapidly even if the arrangement of only one carbon atom of the gelling agent is changed. The agent was synthesized, and various types of organic-inorganic hybrid silica nanotubes were prepared from binding with TEOS, a precursor of silica.

Recently, researches to control the shape of nanotubes have been activated based on these studies, and the shape of the prepared nanotubes is known to vary in shape or shape due to the influence of temperature, light, pH, and concentration. have. In addition, research into the insertion of alkali metals (Li, Na, K, Rb, Cs) into the carbon nanotubes and various inorganic nanotubes is being actively conducted. Most studies have focused on the amount of lithium intercalated due to the industrial applicability of lithium (Li) secondary ion batteries, and attention has been paid to electron transfer into nanotubes in potassium and rubidium insertions. These findings illustrate the potential for new nanodevices. However, although many studies have been conducted until recently, the structural properties of the nanotubes and their correlation with the gelling agent have not been clearly identified.

Not only is it difficult to synthesize a derivative used as a template when preparing a nanotube using an organic gelling agent, there are many problems in economics for industrial use.

In general, the manufacturing method of the nanotube using the organic-inorganic complex is as follows. A method of preparing an organic-inorganic composite in the form of nanotubes by using an organic material such as carbon nanotubes or a biomaterial as a template and synthesizing an inorganic precursor is transmitted. That is, by using an organic compound having an appropriate cation moiety as a template and adding an inorganic precursor having an adsorbing anion thereto, an organic-inorganic complex and a metal oxide in the form of nanotubes can be obtained by hydrogen bonding between a cation and an anion. It is called the casting method.

The inventions of patent registration Nos. 10-0910334 and 10-0910335, some of which are pre- filed and registered, have been prepared using difemethylethylenediamine as a starting material to prepare a low molecular neutral gelling agent having an asymmetric carbon of difemethylethylenediamide. In addition, after preparing a chiral cation gelling agent of diphenyl dimethyl diamide having a cation by using diphenyl dimethyl diamine as a starting material, it is mixed by 20:80 ~ 80:20 (preferably 1: 1) After the gel was prepared, the inorganic precursor silicon alkoxide was added to prepare an organic-inorganic composite. Then, the technique which manufactured the chiral helical silica nanotube by sintering an organic-inorganic composite and removing organic substance is demonstrated.

However, the above method has a disadvantage in that it is difficult to manufacture and costly to manufacture because the chiral cationic gelling agent having a complex structure is required to go through several synthesis steps.

Therefore, there is a need for a method of manufacturing spiral silica nanotubes in a simpler and more convenient way.

 The present invention has been proposed to solve such a problem, and an object of the present invention is to simply and easily purchase achiral cationic gelling agent that can be easily and easily purchased instead of using a chiral cationic gelling agent prepared through a complicated process. And to provide a method for producing a silica nanotube simply.

Another object of the present invention is to provide a method for producing silica nanotubes while arbitrarily adjusting the degree of twist and the direction of twist of the spiral silica nanotubes to be produced.

The silica nanotube manufacturing method of the present invention is a method for producing silica nanotubes having a spiral structure using a mixed gelling agent of a chiral neutral gelling agent and a cationic gelling agent, also referred to as the cationic gelling agent (or 'organic gelling agent'). ) Is characterized in that a non-chiral cationic gelling agent is used.

Preferably, the achiral cationic gelling agent is an alkyltrimethylammonium bromide having an alkyl group, more preferably the trimethylammonium bromide has C6 to C20 carbon atoms of the alkyl group, and in particular, the alkyltrimethylammonium bromide is dodecyltrimethylammonium. Bromide is used.

Wherein said chiral neutral gelling agent is diphenylethylenediamide.

Preferably, the degree of directivity and the degree of twisting of the helical silica nanotubes is determined by the optical purity of the chiral neutral gelling agent when preparing the silica nanotubes having the helical structure.

The manufacturing method of the helical silica nanotubes of the present invention is simple and easy to use by using a simple, easily available and inexpensive achiral cationic gelling agent, instead of using a chiral cationic gelling agent prepared through a complicated process. Since the nanotubes can be manufactured, the price is low, economical, and can be manufactured without undergoing a complicated process, thereby having an excellent workability. In other words, in the present invention, it is possible to prepare spiral nanoparticles using dodecyltrimethylammonium bromide, which is a readily available and inexpensive non-chiral compound. The process for producing silica nanotubes was significantly improved.

In addition, by controlling the amount of the optical isomer of the chiral neutral gelling agent to control the optical purity, there is an advantage that can be produced spiral silica nanotube by adjusting the degree of twist, the direction of the twist.

The inventors of the present invention use a commercially available achiral cationic gelling agent instead of using a chiral cationic gelling agent (or 'organic gelling agent') produced by a complex process to produce spiral silica nanotubes of desired shape. The question of whether it can be manufactured is approached with a starting point, and the present invention has been completed.

That is, the present inventors cationic gelation of trimethylammonium bromide, which is a non-chiral compound having no asymmetric carbon in the low molecular chiral (also called 'chiral') neutral gelling agent having an asymmetric carbon of diphenylethylenediamide. Chiral spiral silica nanotubes were prepared according to the sol-gel molding method using the organic gel mixed with zero as a template.

Preferably, alkyl trimethylammonium bromide has C ₆ -C ₂₀ carbon atoms in the alkyl group, and more preferably dodecyltrimethylammonium bromide having C ₁₁ carbon atoms in the alkyl group is used. When the carbon number is low, the spiral nanotubes cannot be manufactured. When the carbon number is too high, it is difficult to control the process. Preferably, dodecyltrimethylammonium bromide having an alkyl group of C ₁₁ is used.

In more detail, first, a chiral neutral gelling agent is prepared in the manner mentioned in the prior art. The preparation method of the chiral neutral gelling agent will be the same as that of the prior art (Patent Nos. 10-0910334 and 10-0910335).

Then, instead of the conventional chiral cationic gelling agent, dodecyltrimethylammonium bromide, a readily available and inexpensive non-chiral compound, is mixed. The mixing ratio of the chiral neutral gelling agent and the achiral cationic gelling agent is 20 to 80:80 to 20, preferably in a 1: 1 mass ratio. As the amount of either gelling agent increases, the amount of spherical silica nanotubes produced increases rather than the amount of spiral nanotubes finally produced. Therefore, it is preferable that 1: 1 is preferably added in mass ratio.

Thus, an organic gel made by mixing a chiral neutral gelling agent with an achiral cationic gelling agent (dodecyltrimethylammonium bromide), an inorganic precursor, silicon alkoxide TEOS (tetraethylorthosilicate), alcohol as a solvent, benzylamine as a catalyst, and hydrolysis For the polycondensation reaction, water is added to prepare an organic-inorganic complex having nano size.

Thereafter, the organic and inorganic composites prepared are sintered to remove organic substances, thereby finally preparing chiral silica nanotubes having a spiral structure. 1 is a view illustrating an example of a method of manufacturing silica nanotubes.

On the other hand, in the finally prepared helical nanotubes, the degree of orientation and twisting of the silica nanotubes is determined by the optical purity of the neutralizing gelling agent, that is, the mixing ratio of the optical isomers R type and S type of the neutralizing gelling agent. In other words, when preparing silica nanotubes using alkyltrimethylamonium bromide, which is a non-chiral compound, the amount of the optical isomer of the chiral neutral gelling agent is changed, that is, the optical purity of the chiral neutral gelling agent is changed. The degree of directionality and twisting of the silica nanotubes can be controlled.

In addition, when preparing the spiral silica nanotubes, the degree of orientation and twisting of the spiral silica nanotubes were controlled according to the optical purity of the chiral neutral gelling agent (that is, the mixing ratio of the R-type and S-type optical isomers).

In the case of controlling the degree of aromaticity and the degree of twisting, the cationic gelling agent included in the neutral gelling agent does not necessarily have to use an achiral cationic gelling agent, and a chiral cationic gelling agent prepared through a complicated step may be used. Even in this case, the purity of the neutral gelling agent determines the degree of orientation and the degree of twisting of the silica nanotubes.

Hereinafter, specific examples will be described, but the scope of the present invention is not necessarily limited thereto.

Example 1. (1S, 2S) -diphenylethylenediamide (specifically, an alkyl group (C ₁₁ Synthesis of (1S, 2S) -diphenylethylenediamide)

                                            (1S, 2S) G1

a. Lauroyl chloride, Et ₃ N, CH ₂ Cl ₂ , rt, 20hr

The (1S, 2S) substituted with an alkyl group (C ₁₁₎ - synthesis of diphenyl-ethylene diamide is as follows (hereinafter, the (1S, 2S) substituted with an alkyl group (C ₁₁₎ -. Diphenylethylene diamide Is designated as "(1S, 2S) G1" and named "(1S, 2S) Gelator 1")

First, add (1S, 2S)-(-)-diphenylethylenediamine (0.20 g, 0.94 mmol) to a 50 ml round bottom flask, add purified Dichloromethane (5 ml), and add triethylamine (0.53 ml, 3.80 mmol). After stirring. Lauroyl chloride (0.49 ml, 2.07 mmol) was dissolved in purified Dichloromethane (5 ml) using a dropping funnel, slowly added to a 50 ml round bottom flask and stirred at room temperature for 20 hours. Confirm that the reaction was completed by TLC, 1N-HCl (aq) and Dichloromethane and extract the organic layer using the Separation funnel. Put 1N-NaOH (aq) and Dichloromethane again and extract the organic layer using Separation funnel. After removing the water remaining as sodium sulfate in the extracted organic layer, and filtered through a filter paper, the filtrate is concentrated under reduced pressure to remove the solvent. Recrystallization using dichloromethane and Hexane gave 0.35 g (yield: 65.0%) of white (1S, 2S) G 1.

¹ H-NMR (CDCl ₃ , ppm): δ = 0.87 (t, J = 6.3 Hz, 6H), 1.24 (s, 32H), 1.59 (m, 4H), 2.18 (t, J = 7.2 Hz, 4H) , 5.24 (dd, J = 4.8, 2.4 Hz, 2H), 6.81 (s, 2H), 7.09-7.20 (m, 10H); FT-IR (KBr): ˜v = 3316, 3062, 3032, 2920, 2850, 1642, 1535, 1455, 701 cm ⁻¹ ; ¹³ C-NMR (CDCl ₃ , ppm): δ = 14.26, 22.88, 26.01, 29.51, 29.54, 29.59, 29.73, 29.85, 32.12, 36.75, 59.72, 125.40, 127.70, 128.01, 128.77, 138.87, 174.81; mp = 137-137.7 ° C .; [a] _23.3 D = 71.98 (c = 0.1, CHCl ₃ )

Example 2. (1R, 2R) -diphenylethylenediamide (specifically, an alkyl group (C ₁₁ Synthesis of (1R, 2R) -diphenylethylenediamide)

(1R,2R)G1

(1R, 2R) G1

a. Lauroyl chloride, Et ₃ N, CH ₂ Cl ₂ , rt, 20 hr

Synthesis process of (1R, 2R) -diphenylethylenediamide substituted with alkyl group (C11) is as follows (Hereinafter, (1R, 2R) -diphenylethylenediamide substituted with alkyl group (C ₁₁ ) "(1R, 2R) G1" and "(1R, 2R) Gelator 1")

First, add (1R, 2R)-(+)-Diphenylethylenediamine (0.20 g, 0.94 mmol) to a 50 ml round bottom flask, add purified Dichloromethane (5 ml), and add triethylamine (0.53 ml, 3.80 mmol). After stirring, it is stirred. Using a dropping funnel, Lauroyl chloride (0.49 ml, 2.07 mmol) was dissolved in purified Dichloromethane (5 ml) and slowly added to a 50 ml round bottom flask and stirred at room temperature for 20 hours. Confirm that the reaction was completed by TLC, 1N-HCl (aq) and Dichloromethane and extract the organic layer using the Separation funnel. Put 1N-NaOH (aq) and Dichloromethane again and extract the organic layer using Separation funnel. After removing the water remaining as sodium sulfate in the extracted organic layer, and filtered through a filter paper, the filtrate is concentrated under reduced pressure to remove the solvent. 0.35 g (yield: 65%) of (1R, 2R) G1 was obtained by recrystallization using dichloromethane and Hexane.

¹ H-NMR (CDCl ₃ , ppm): δ = 0.87 (t, J = 6.3 Hz, 6H), 1.24 (s, 32H), 1.59 (m, 4H), 2.18 (t, J = 7.2 Hz, 4H) , 5.24 (dd, J = 4.8, 2.4 Hz, 2H), 6.81 (s, 2H), 7.09-7.20 (m, 10H); ¹³ C-NMR (CDCl ₃ , ppm): δ = 14.26, 22.88, 26.01, 29.51, 29.54, 29.59, 29.73, 29.85, 32.12, 36.75, 59.72, 125.40, 127.70, 128.01, 128.77, 138.87, 174.81; FT-IR (KBr): ˜v = 3316, 3062, 3032, 2920, 2850, 1642, 1535, 1455, 701 cm < -1 >; mp = 137-137.7 ° C .; [a] _22.4 D = -72.99 (c = 0.1, CHCl ₃ )

Example 3. Synthesis of (±) G1

                                             (±) G1

a. Lauroyl chloride, Et ₃ N, CH ₂ Cl ₂ , rt, 20hr

Synthesis of a diphenyl ethylene diamide substituted with alkyl groups (C ₁₁₎ is indicated as follows: (In the following, with the diphenylethylene the diamide "(±) G1" substituted with an alkyl group (C _11), and " (±) Gelator 1 ").

Into a 50 ml round bottom flask, 1,2- (±) -Diphenylethylenediamine (0.20 g, 0.94 mmol) was added, purified dichloromethane (5 ml) was added, triethylamine (0.53 ml, 3.80 mmol) was added, followed by stirring. Dissolve lauroyl chloride (0.49 ml, 2.07 mmol) in purified Dichloromethane (5 ml) using a dropping funnel and slowly add to a 50 ml round bottom flask. Stir at room temperature for 20 hours. Confirm that the reaction was completed by TLC, 1N-HCl (aq) and Dichloromethane and extract the organic layer using the Separation funnel. Put 1N-NaOH (aq) and Dichloromethane again and extract the organic layer using Separation funnel. After removing the water remaining as sodium sulfate in the extracted organic layer, and filtered through a filter paper, the filtrate is concentrated under reduced pressure to remove the solvent. Recrystallization using dichloromethane and hexane gave 0.35 g (yield: 65.0%) of (±) G1.

¹ H-NMR (CDCl ₃ , ppm): δ = 0.87 (t, J = 6.3 Hz, 6H), 1.24 (s, 32H), 1.59 (m, 4H), 2.18 (t, J = 7.2 Hz, 4H) , 5.24 (dd, J = 4.8, 2.4 Hz, 2H), 6.81 (s, 2H), 7.09-7.20 (m, 10H); FT-IR (KBr): ˜v = 3316, 3062, 3032, 2920, 2850, 1642, 1535, 1455, 701 cm ⁻¹ ; ¹³ C-NMR (CDCl ₃ , ppm): δ = 14.26, 22.88, 26.01, 29.51, 29.54, 29.59, 29.73, 29.85, 32.12, 36.75, 59.72, 125.40, 127.70, 128.01, 128.77, 138.87, 174.81; mp = 168.7 ~ 169.5 ℃

Experimental Example 1 Preparation of Silica Nanotubes Using (1S, 2S) G1 and Dodecyltrimethylammonium bromide

In Experimental Example 1 synthesized in Example 1 in a 2 ml container in the same manner as in Figure 1 2 mg of the neutral gelling agent (1S, 2S) G1 and 2 mg of the non-chiral cationic gelling agent Dodecyltrimethylammonium bromide are mixed in a 1: 1 mass ratio and mixed with 100 mL of the organic solvent. Heat is then applied until the solid gelling agent is completely dissolved.

After cooling, check to see if it becomes a gel.When the gel is added, add 16 mL of silicon alkoxide, tetraethyl orthosilicate (TEOS), 10 mL of benzylamine, and 10 mL of water, seal, and heat until completely dissolved, and heat at room temperature for 7 days. Keep it.

After slowly raising the temperature to 200 ℃ for 3 hours in an argon atmosphere, and maintaining the temperature at 200 ℃ for 2 hours, and slowly raising the temperature to 500 ℃ for 6 hours continuously and incubated at 500 ℃ for 2 hours . In the state of continuous air supply, slowly raise the temperature to 200 ℃ for 3 hours, maintain the temperature at 200 ℃ for 2 hours, and slowly raise the temperature to 500 ℃ for 6 hours continuously, and then at 500 ℃ for 2 hours. Conversation while

The organic material was removed through the painting process to obtain a silica nanotube having a spiral structure in the right hand direction, and FIG. 2 is a SEM and a TEM photograph of the spiral silica nanotube obtained through Experimental Example 1. FIG.

Experimental Example 2. Preparation of Silica Nanotubes Using (1R, 2R) G1 and Dodecyltrimethylammonium bromide

In Experimental Example 2 synthesized in Example 2 The experiment was performed in the same manner as in Experiment 1 using 2 mg of a neutral gelling agent (1R, 2R) G1 and 2 mg of a non-chiral cationic gelling agent Dodecyltrimethylammonium bromide. Figure 3 is a SEM, TEM picture of the helical silica nanotubes obtained in Experimental Example 2, it was confirmed that the silica nanotubes having a spiral structure in the left hand direction.

Experimental Example 3. Preparation of Silica Nanotubes Using (±) G1 and Dodecyltrimethylammonium bromide

In Experimental Example 3 synthesized in Example 3 Experiment using the same method as Experimental Example 1 using a neutral gelling agent (±) G1 2mg and a non-chiral cationic gelling agent dodecyltrimethylammonium bromide (2mg).

4 is a SEM, TEM picture of the silica nanotubes obtained through the Experimental Example 3, it was confirmed that the silica nanotubes having a linear structure does not appear a spiral structure.

When producing silica nanotubes having a spiral structure by using a neutral gelling agent and a cationic gelling agent, a chiral cationic gelling agent that is difficult to synthesize is not synthesized and used at a low price as in Experimental Examples 1, 2, and 3 Even by using a non-chiral cationic gelling agent which can be easily obtained, the spiral silica nanotubes having the same twisting direction as in the case of using a conventional chiral cationic gelling agent could be prepared. The spiral direction of the tubes is summarized in Table 1.

Table 1. Spiral directions of silica nanotubes using non-chiral cationic gelling agents

Neutral gelling agent Cationic Gelling Agent Helix direction (1S, 2S) G1 Dodecyltrimethylammonium bromide Right hand direction (1R, 2R) G1 Dodecyltrimethylammonium bromide Left hand direction (±) G1 Dodecyltrimethylammonium bromide Straight

Experimental Example 4.  Preparation of Silica Nanotubes According to Optical Purity of Neutral Gelling Agent

In Experimental Example 4, the chirality synthesized in Example 1 in the same manner as in FIG. Neutral gelling agent (1S, 2S) G1 and chirality synthesized in Example 2 The mixing ratio of the neutral gelling agent (1R, 2R) G1 is mixed as shown in Table 2. That is, the direction and the degree of twist of the helical silica nanotubes were adjusted according to the optical purity by the mixing ratio of the R type and the S type of the chiral neutral gelling agent. The results are included in Table 2.

Table 2. Spiral direction of silica nanotubes according to optical purity of neutral gelling agent

(1S, 2S) G1 (1R, 2R) G1 Spiral direction of nanotubes One 9 (80% ee) Left hand direction 2 8 (60% ee) Left hand direction 3 7 (40% ee) Left hand direction 4 6 (20% ee) Left hand direction + straight 5         5 (0% ee) Straight 6 (20% ee) 4 Right hand direction + straight 7 (40% ee) 3 Right hand direction 8 (60% ee) 2 Right hand direction 9 (80% ee) One Right hand direction

 When (1R, 2R) G1 and (1S, 2S) G1 were tested at a ratio of 9: 1, 8: 2, and 7: 3 as shown in FIG. 5, silica nanotubes showing a spiral structure in the left hand direction were prepared.

When the experiment was performed at a ratio of 6: 4, silica nanotubes having a left-handed structure and a linear structure were simultaneously produced.

As the ratio of (1R, 2R) G1 decreased, the twist of the spiral silica nanotubes was released.

In addition, when (1S, 2S) G1 and (1R, 2R) G1 were tested at a ratio of 9: 1, 8: 2, and 7: 3, silica nanotubes showing a spiral structure in the right hand direction were prepared. When experimenting with the ratio of the silica nanotubes appearing at the same time the right hand and the linear structure was produced. When the ratio of (1S, 2S) G1 is reduced, the twist of the spiral silica nanotubes is released as in the case where the ratio of (1R, 2R) G1 is reduced.

Experimental Example 5.  Unipolar Polarization Measurement of Silica Nanotubes

The size of planar polarization was measured for the silica nanotubes prepared in Experimental Example 4. In order to see how the planar polarization changes with the optical purity of the neutral gelling agent, (1S, 2S) G1 and (1R, 2R) G1 were converted to 10: 0, 9: 1, 7: using CD (circular dichroism) spectra. 3, 5: 5, 3: 7, 1: 9, and 0:10 were measured by dissolving in chloroform. As a result, when (1S, 2S) G1 and (1R, 2R) G1 were tested at a ratio of 10: 0, 9: 1, 7: 3 as shown in FIG. It can be seen that the size of the decrease.

In contrast, when (1R, 2R) G1 and (1S, 2S) G1 were tested at the ratio of 10: 0, 9: 1, and 7: 3, the decrease in the ratio of (1R, 2R) G1 also reduced the magnitude of planar polarization. Could know. And finally, no polarization was shown at a ratio of 5: 5.

These results can be seen that the twist of the helical silica nanotubes change depending on the size of the plane polarization. That is, according to the optical purity of the gelling agent can be adjusted the degree of orientation and twist of the helical silica nanotubes.

The foregoing descriptions are merely examples according to preferred embodiments, and the scope of the present invention is not limited to the above embodiments. The technical scope of the present invention is shown in the claims, and various changes, substitutions, and alterations can be made by those skilled in the art without departing from the spirit or scope of the invention described in the claims.

1 is an example showing a method of manufacturing silica nanotubes.

Figure 2 is a SEM, TEM image of silica nanotubes prepared by (1S, 2S) G1 + Dodecyltrimethylammonium bromide.

Figure 3 is a SEM, TEM photograph of silica nanotubes prepared by (1R, 2R) G1 + Dodecyltrimethylammonium bromide.

Figure 4 is a SEM, TEM photograph of the silica nanotubes prepared by (±) G1 + Dodecyltrimethylammonium bromide.

5 is a SEM photograph of silica nanotubes prepared according to the ratio of the neutral gelling agent, (1S, 2S) G1 and (1R, 2R) G1.

6 is a CD spectrum according to the optical purity of the neutral gelling agent G1

Claims (7)

In the method for producing a silica nanotube having a spiral structure using a mixed gelling agent of a chiral neutral gelling agent and a cationic gelling agent, The cationic gelling agent is a method for producing a silica nanotube having a chiral spiral structure, characterized in that a non-chiral cationic gelling agent is used. The method of claim 1, Wherein the non-chiral cationic gelling agent is alkyltrimethylammonium bromide. 3. The method of claim 2, The alkyl trimethylammonium bromide is a method for producing a silica nanotube having a chiral helical structure, characterized in that the alkyl group has C6 to C20. 3. The method of claim 2, The alkyltrimethylammonium bromide is a dodecyltrimethylammonium bromide method of producing a silica nanotube having a chiral helical structure, characterized in that. The method of claim 1, The chiral neutral gelling agent is a method for producing a silica nanotube having a chiral helical structure, characterized in that diphenylethylenediamide. The method of claim 1, The degree of orientation and twisting of the helical silica nanotubes is determined according to the optical purity of the chiral neutral gelling agent. A silica nanotube having a chiral spiral structure produced by the manufacturing method according to any one of claims 1 to 6.

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