Preparation method of carbon dioxide response type organic nanotube

Abstract

The invention discloses a carbon dioxide response type organic nanotube preparation method, which comprises: 1, swelling: placing Rink resin in a solid phase extraction column, adding a 4-methylpiperidine / DMF mixed solution, shaking at a room temperature to swell the resin, and removing Fomc group protection to obtain a product A; step 2, washing: adding DMF into the product A, repeatedly shaking and carrying out suction filtration, and then repeatedly washing with DMF for multiple times to obtain a product B; and step 3, carrying out primary amidation. According to the preparation method of the carbon dioxide response type organic nanotube, an amphiphilic star-shaped peptoid copolymer with accurate and controllable sequence and chain length is synthesized, the one-dimensional organic nanotube with uniform size is obtained, and a carbon dioxide response group histamine structure is simply introduced into a peptoid system, so that the carbon dioxide response type organic nanotube is obtained. The one-dimensional organic nanotube is endowed with a unique carbon dioxide response characteristic; the preparation process has the characteristics of simplicity, feasibility, good repeatability, high stability and the like.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of organic tubular nano materials, in particular to a method for preparing carbon dioxide responsive organic nano tubes. Background Art

[0002] Organic tubular materials are a new type of organic nanomaterials. Due to their unique physical and chemical properties, they have potential application prospects in the fields of gas adsorption, fluorescent materials, molecular probes, etc., and have therefore attracted widespread attention.

[0003] Peptoids are non-natural mimics of peptides and proteins composed of repeated N-substituted glycine monomer units, in which the side chains are covalently attached to nitrogen atoms on the main chain of the molecule instead of α-carbon atoms, and the main chain lacks hydrogen bonds. These unique structures provide it with unique physical and chemical properties. As a new type of biomimetic material, peptoids have made rapid progress in synthesis methods and performance research. However, there are few reports on the synthesis of responsive peptoid molecules, especially one-dimensional organic nanotube materials further assembled from stimulus-responsive peptoid molecules.

[0004] Carbon dioxide is environmentally friendly, non-toxic, and inexpensive. It is a new type of trigger factor with unique advantages, which has attracted widespread attention to carbon dioxide-responsive polymer materials. Histamine is a planar five-membered heterocyclic compound containing two nitrogen atoms. As a carbon dioxide-sensitive group, it can efficiently capture and release CO2 gas molecules through the protonation and deprotonation of secondary and tertiary amines in the five-membered ring, and has broad development prospects.

[0005] Organic nanomaterials assembled from molecules with precisely controllable sequences (such as DNA, proteins, peptides, etc.) have excellent characteristics such as large specific surface area, tunable structure, unique molecular structure and adjustable functional groups. However, due to the complexity of their molecular sequence and structure, they are usually difficult to synthesize using conventional physical and chemical methods, and it is difficult to accurately predict the interactions between molecules and the assembly structure, which seriously limits the controllable synthesis and development prospects of organic ultra-thin nanomaterials.

[0006] Therefore, in view of the above problems, a method for preparing carbon dioxide responsive organic nanotubes is designed to better meet the actual use needs. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing carbon dioxide responsive organic nanotubes to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a method for preparing carbon dioxide responsive organic nanotubes, comprising the following steps:

[0009] Step 1: Swelling: Place the Rink amide resin in a solid phase extraction column, add a 4-methylpiperidine / DMF mixed solution and shake at room temperature to swell the resin, remove the Fomc group protection, and obtain product A;

[0010] Step 2: Washing: Add DMF to product A, shake and filter repeatedly, and then rinse with DMF several times to obtain product B;

[0011] Step 3: primary amidation, adding bromoacetic acid solution and N,N'-diisopropyldiimide (DIC) / DMF mixed solution to product B, shaking at room temperature for amidation reaction, then adding DMF solution, repeatedly shaking, filtering, and rinsing several times to obtain product C;

[0012] Step 4: 4-bromobenzylamine substitution: add 4-bromobenzylamine solution to product C, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product D;

[0013] Step 5: Repeat the amidation and 4-p-bromobenzylamine substitution process six times in sequence to obtain a product E with six 4-p-bromobenzylamine units;

[0014] Step 6: secondary amidation, amidating the product E according to the operation of step 3 to obtain product F;

[0015] Step 7: Ethylenediamine substitution: add ethylenediamine solution to product F, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product G;

[0016] Step 8: Amidation three times, amidating the product G according to the operation of step 3 to obtain product H;

[0017] Step 9: 2-methoxyethylamine substitution: add 2-methoxyethylamine solution to product H, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product I;

[0018] Step 10: Quaternary amidation, adding chloroacetic acid solution and N,N'-diisopropyldiimide (DIC) / DMF mixed solution to product I, shaking at room temperature for amidation reaction, then adding DMF solution, repeatedly shaking, filtering, and rinsing for several times to obtain product J;

[0019] Step 11: Histamine substitution, add histamine solution to product J, shake at 40°C for substitution reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product K;

[0020] Step 12: Peptoid cleavage, pure water and trifluoroacetic acid (TFA) are added to the product K to cleave the resin to obtain a final crude product, the final crude product is filtered and evaporated under a nitrogen gas flow, then the crude product is dissolved in 1 mL of acetonitrile, and then precipitated and centrifuged with anhydrous ether to obtain a peptoid product, then the peptoid product is dissolved in a mixture of pure water and tetrahydrofuran, and freeze-dried to obtain a purified peptoid high-purity sample, and pure water / THF is used as a solvent to prepare a peptoid solution;

[0021] Step 13: Self-assembly. The purified high-purity peptoid sample is prepared into a peptoid solution using pure water / tetrahydrofuran as a solvent and placed under constant temperature conditions. When the tetrahydrofuran evaporates slowly and the solution becomes turbid, the peptoid self-assembles to form a one-dimensional organic nanotube structure, namely, a carbon dioxide-responsive one-dimensional organic nanotube.

[0022] As a preferred embodiment of the above technical solution, the peptoid product in step twelve is an amphiphilic star-shaped peptoid molecule containing a hydrophobic side group of 4-p-bromobenzylamine and a hydrophilic side group of 2-methoxyethylamine and histamine, and its molecular structure is as follows:

[0023]

[0024] As a preferred embodiment of the above technical solution, in step 1, the amount of Rink amide resin added is 100 mg, the volume of the mixed solution of 4-methylpiperidine / DMF added is 3 mL, and the shaking time is 40 min, wherein the volume ratio of 4-methylpiperidine to DMF in 4-methylpiperidine / DMF is 1:3.

[0025] As a preferred embodiment of the above technical scheme, in step three, the amount of bromoacetic acid used is 1.5 mL, and the amount of N-N'-diisopropyl diimine (DIC) / DMF mixed solution added is 0.4 mL, wherein the concentration of the bromoacetic acid solution is 0.6 mol / L, the volume ratio of N-N'-diisopropyl diimine solution and DMF solution in the N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 1: 1, and the shaking time after adding the bromoacetic acid solution and N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 10min.

[0026] As a preferred embodiment of the above technical solution, in step 4, the amount of 4-p-bromobenzylamine solution is 1.5 mL, the concentration is 0.6 mol / L, and the shaking time after adding the 4-p-bromobenzylamine solution is 15 min.

[0027] As a preferred embodiment of the above technical solution, in step seven, the amount of ethylenediamine solution used is 1.5 mL, the concentration is 0.6 mol / L, and the shaking time after adding the ethylenediamine solution is 2 h.

[0028] As a preferred embodiment of the above technical scheme, in step eight, the amount of bromoacetic acid used is 1.5 mL, and the amount of N-N'-diisopropyl diimine (DIC) / DMF mixed solution added is 0.8 mL, wherein the concentration of the bromoacetic acid solution is 1.2 mol / L, the volume ratio of N-N'-diisopropyl diimine solution and DMF solution in the N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 1: 1, and the shaking time after adding the bromoacetic acid solution and N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 15min.

[0029] As a preferred embodiment of the above technical solution, in step nine, the amount of 2-methoxyethylamine solution used is 1.5 mL, the concentration is 1.2 mol / L, and the shaking time after adding the 2-methoxyethylamine solution is 20 min.

[0030] As a preferred embodiment of the above technical scheme, in step ten, the amount of chloroacetic acid used is 1.5 mL, and the amount of N-N'-diisopropyl diimine (DIC) / DMF mixed solution added is 0.8 mL, wherein the concentration of the chloroacetic acid solution is 1.2 mol / L, the volume ratio of N-N'-diisopropyl diimine solution and DMF solution in the N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 1: 1, and the shaking time after adding the chloroacetic acid solution and the N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 20 min.

[0031] As a preferred embodiment of the above technical solution, in step eleven, the amount of the histamine solution is 1.5 mL, the concentration is 1.2 mol / L, and the shaking time after adding the histamine solution is 1 day.

[0032] As a preferred embodiment of the above technical solution, in step 12, the volume ratio of pure water and trifluoroacetic acid added to product K is 5:95, the stirring time is 20 minutes, the temperature is 40°C, and the storage temperature of the peptoid product is 0°C.

[0033] As a preferred embodiment of the above technical solution, in step twelve, the peptoid product is dissolved in a mixture of pure water and tetrahydrofuran, the volume ratio of pure water to tetrahydrofuran is 1:1, the concentration of the peptoid solution is 2 μmol / L, and the evaporation temperature is 4°C.

[0034] Compared with the prior art, the invention has the following beneficial effects: the preparation method of the carbon dioxide responsive organic nanotube adopts solid phase synthesis technology, uses peptoids as the main chain structure, uses 4-p-bromobenzylamine as the hydrophobic side group, and uses 2-methoxyethylenediamine and histamine as the hydrophilic side groups to synthesize an amphiphilic star-shaped peptoid molecule;

[0035] Then, a solution self-assembly method is used in a mixed solution of tetrahydrofuran and pure water, using the good crystallization performance of the hydrophobic group 4-p-bromobenzylamine as a driving force, and 2-methoxyethylenediamine and histamine as hydrophilic groups to obtain a one-dimensional organic nanotube material with carbon dioxide responsiveness. The present invention designs and synthesizes an amphiphilic star-shaped peptoid copolymer with precisely controllable sequence and chain length, obtains a one-dimensional organic nanotube with uniform size, and simply introduces the carbon dioxide responsive group histamine structure into the peptoid system, giving the one-dimensional organic nanotube a unique carbon dioxide responsive property;

[0036] The preparation process is simple, easy, reproducible, and stable; and the one-dimensional organic nanotube material prepared by the invention has broad application prospects in gas adsorption, biomedicine, molecular detection, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a TEM image of the assembly in Example 2 of the present invention;

[0038] Figure 2 is an AFM image of the assembly in Example 2 of the present invention;

[0039] Figure 3 is a TEM image of the assembly after CO2 response in Example 2 of the present invention;

[0040] Figure 4 is a graph showing changes in pH value of the assembly solution in Example 2 of the present invention;

[0041] Figure 5 is a Zeta potential curve of the assembly solution in Example 2 of the present invention;

[0042] Figure 6 This is a diagram showing the Zeta potential change of the assembly solution in Example 2 of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Embodiment 1

[0045] The present invention provides a technical solution: a method for preparing carbon dioxide responsive organic nanotubes, comprising the following steps:

[0046] Step 1: Swelling: Place the Rink amide resin in a solid phase extraction column, add a 4-methylpiperidine / DMF mixed solution and shake at room temperature to swell the resin, remove the Fomc group protection, and obtain product A;

[0047] Step 2: Washing: Add DMF to product A, shake and filter repeatedly, and then rinse with DMF several times to obtain product B;

[0048] Step 3: primary amidation, adding bromoacetic acid solution and N,N'-diisopropyldiimide (DIC) / DMF mixed solution to product B, shaking at room temperature for amidation reaction, then adding DMF solution, repeatedly shaking, filtering, and rinsing several times to obtain product C;

[0049] Step 4: 4-bromobenzylamine substitution: add 4-bromobenzylamine solution to product C, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product D;

[0050] Step 5: Repeat the amidation and 4-p-bromobenzylamine substitution process six times in sequence to obtain a product E with six 4-p-bromobenzylamine units;

[0051] Step 6: secondary amidation, amidating the product E according to the operation of step 3 to obtain product F;

[0052] Step 7: Ethylenediamine substitution: add ethylenediamine solution to product F, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product G;

[0053] Step 8: Amidation three times, amidating the product G according to the operation of step 3 to obtain product H;

[0054] Step 9: 2-methoxyethylamine substitution: add 2-methoxyethylamine solution to product H, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product I;

[0055] Step 10: Quaternary amidation, adding chloroacetic acid solution and N,N'-diisopropyldiimide (DIC) / DMF mixed solution to product I, shaking at room temperature for amidation reaction, then adding DMF solution, repeatedly shaking, filtering, and rinsing for several times to obtain product J;

[0056] Step 11: Histamine substitution, add histamine solution to product J, shake at 40°C for substitution reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product K;

[0057] Step 12: Peptoid cleavage, pure water and trifluoroacetic acid (TFA) are added to the product K to cleave the resin to obtain a final crude product, the final crude product is filtered and evaporated under a nitrogen gas flow, then the crude product is dissolved in 1 mL of acetonitrile, and then precipitated and centrifuged with anhydrous ether to obtain a peptoid product, then the peptoid product is dissolved in a mixture of pure water and tetrahydrofuran, and freeze-dried to obtain a purified peptoid high-purity sample, and pure water / THF is used as a solvent to prepare a peptoid solution;

[0058] Step 13: Self-assembly. The purified high-purity peptoid sample is prepared into a peptoid solution using pure water / tetrahydrofuran as a solvent and placed under constant temperature conditions. When the tetrahydrofuran evaporates slowly and the solution becomes turbid, the peptoid self-assembles to form a one-dimensional organic nanotube structure, namely, a carbon dioxide-responsive one-dimensional organic nanotube.

[0059] The present embodiment provides a method for preparing a carbon dioxide-responsive organic nanotube, which adopts a solid phase synthesis technique, uses a peptoid as a main chain structure, uses 4-p-bromobenzylamine as a hydrophobic side group, and uses 2-methoxyethylenediamine and histamine as hydrophilic side groups to synthesize an amphiphilic star-shaped peptoid molecule; then, by a solution self-assembly method, in a mixed solution of tetrahydrofuran and pure water, the good crystallization performance of the hydrophobic group 4-p-bromobenzylamine is used as a driving force, and 2-methoxyethylenediamine and histamine are used as hydrophilic groups to obtain a one-dimensional organic nanotube material with carbon dioxide responsiveness. The present invention designs and synthesizes an amphiphilic star-shaped peptoid copolymer with precisely controllable sequence and chain length, obtains a one-dimensional organic nanotube with uniform size, and simply introduces the carbon dioxide responsive group histamine structure into the peptoid system, giving the one-dimensional organic nanotube a unique carbon dioxide responsive characteristic; the preparation process is simple and easy, has good repeatability, and has high stability; and the one-dimensional organic nanotube material prepared by the present invention has broad application prospects in gas adsorption, biomedicine, molecular detection, etc.

[0060] In a further embodiment of this embodiment, the peptoid product in step twelve is an amphiphilic star-shaped peptoid molecule containing a hydrophobic side group of 4-p-bromobenzylamine and a hydrophilic side group of 2-methoxyethylamine and histamine, and its molecular structure is as follows:

[0061]

[0062] The peptoid molecules in this embodiment are amphiphilic star-shaped peptoid copolymers with precisely controllable sequences. The good crystallization properties of the hydrophobic group 4-bromobenzylamine are used as a driving force, 2-methoxyethylenediamine and histamine are used as hydrophilic groups, and the hydrogen bond attraction generated in the solution enables the peptoid molecules to self-assemble in a mixed solution of tetrahydrofuran and pure water to form a one-dimensional organic nanotubular material.

[0063] Embodiment 2

[0064] Based on the first embodiment, this embodiment provides a method for preparing a light-responsive organic ultrathin nanoribbon, comprising the following steps:

[0065] (1) Synthesis of peptoid molecules:

[0066] For details, please refer to the preparation method of histamine-based carbon dioxide responsive organic nanotubes in Example 1, and its molecular structure is shown below.

[0067]

[0068] (2) Preparation of carbon dioxide responsive organic nanotube assemblies:

[0069] The high-purity peptide sample purified in step 12 is prepared into a peptide solution using pure water / tetrahydrofuran as a solvent, and then the tetrahydrofuran is slowly evaporated at a constant temperature of 4°C to obtain a one-dimensional organic nanotube structure, the specific morphology of which is shown in the attached figure of the specification. Figure 1-2 As shown in the figure, it can be seen that the obtained assembly presents a one-dimensional nanotube structure with uniform size.

[0070] (3) Preparation of carbon dioxide responsive organic nanotube assemblies:

[0071] The assembly solution prepared in step 13 was diluted to 0.5 μmol / mL, and CO2 gas was introduced into the assembly solution using a high-purity CO2 cylinder for 20 min at a flow rate of 20 mL / min. The morphology of the nanotubes changed, and the specific morphology is shown in the attached figure of the specification. Figure 3 As shown in the figure, it can be seen that the tube wall of the one-dimensional nanotube assembly becomes thinner, the tube diameter increases, and the structure is stable. Then, a high-purity N2 cylinder is used to pass N2 gas into the assembly solution for 20 minutes to remove CO2 gas in the solution, with a flow rate of 20mL / min. This process is repeated three times, and the pH value and Zeta potential changes of the assembly solution after the gas is passed are measured. The specific pH value and Zeta potential changes are shown in the instructions. Figure 4-6 As shown in the figure, it can be seen that after the CO2 gas was introduced into the assembly solution, the pH value decreased from 8.2 to 4.1, and the Zeta potential increased from 18mV to 38mV; after the N2 gas was introduced, the pH value and Zeta potential returned to the initial value. The process was stable within three cycles.

[0072] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0073] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing carbon dioxide responsive organic nanotubes, characterized in that: The following steps are involved: Step 1: Swelling: Place the Rink amide resin in a solid phase extraction column, add a 4-methylpiperidine / DMF mixed solution and shake at room temperature to swell the resin, remove the Fomc group protection, and obtain product A; Step 2: Washing: Add DMF to product A, shake and filter repeatedly, and then rinse with DMF several times to obtain product B; Step 3: primary amidation, adding bromoacetic acid solution and N,N'-diisopropyldiimide (DIC) / DMF mixed solution to product B, shaking at room temperature for amidation reaction, then adding DMF solution, repeatedly shaking, filtering, and rinsing several times to obtain product C; Step 4: 4-bromobenzylamine substitution: add 4-bromobenzylamine solution to product C, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product D; Step 5: Repeat the amidation and 4-p-bromobenzylamine substitution process six times in sequence to obtain a product E with six 4-p-bromobenzylamine units; Step 6: secondary amidation, amidating the product E according to the operation of step 3 to obtain product F; Step 7: Ethylenediamine substitution: add ethylenediamine solution to product F, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product G; Step 8: Amidation three times, amidating the product G according to the operation of step 3 to obtain product H; Step 9: 2-methoxyethylamine substitution: add 2-methoxyethylamine solution to product H, shake at room temperature for replacement reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product I; Step 10: Quaternary amidation, adding chloroacetic acid solution and N,N'-diisopropyldiimide (DIC) / DMF mixed solution to product I, shaking at room temperature for amidation reaction, then adding DMF solution, repeatedly shaking, filtering, and rinsing for several times to obtain product J; Step 11: Histamine substitution, add histamine solution to product J, shake at 40°C for substitution reaction, add DMF solution after the reaction is completed, shake repeatedly, filter, and rinse repeatedly for several times to obtain product K; Step 12: Peptoid cleavage, pure water and trifluoroacetic acid (TFA) are added to the product K to cleave the resin to obtain a final crude product, the final crude product is filtered and evaporated under a nitrogen gas flow, then the crude product is dissolved in 1 mL of acetonitrile, and then precipitated and centrifuged with anhydrous ether to obtain a peptoid product, then the peptoid product is dissolved in a mixture of pure water and tetrahydrofuran, and freeze-dried to obtain a purified peptoid high-purity sample, and pure water / THF is used as a solvent to prepare a peptoid solution; Step 13: Self-assembly. The purified high-purity peptoid sample is prepared into a peptoid solution using pure water / tetrahydrofuran as a solvent and placed under constant temperature conditions. When the tetrahydrofuran evaporates slowly and the solution becomes turbid, the peptoid self-assembles to form a one-dimensional organic nanotube structure, namely, a carbon dioxide-responsive one-dimensional organic nanotube.

2. The method for preparing a carbon dioxide responsive organic nanotube according to claim 1, characterized in that: The peptoid product in step 12 is an amphiphilic star-shaped peptoid molecule containing a hydrophobic side group of 4-p-bromobenzylamine and a hydrophilic side group of 2-methoxyethylamine and histamine, and its molecular structure is as follows:

3. The method for preparing a carbon dioxide responsive organic nanotube according to claim 1, characterized in that: In step 1, the amount of Rink amide resin added is 100 mg, the volume of the mixed solution of 4-methylpiperidine / DMF added is 3 mL, and the shaking time is 40 min, wherein the volume ratio of 4-methylpiperidine to DMF in 4-methylpiperidine / DMF is 1:

3.

4. The method for preparing a carbon dioxide responsive organic nanotube according to claim 1, characterized in that: In step three, the amount of bromoacetic acid used is 1.5 mL, and the amount of N-N'-diisopropyldiimine (DIC) / DMF mixed solution added is 0.4 mL, wherein the concentration of the bromoacetic acid solution is 0.6 mol / L, the volume ratio of N-N'-diisopropyldiimine solution and DMF solution in the N-N'-diisopropyldiimine (DIC) / DMF mixed solution is 1:1, and the shaking time after adding the bromoacetic acid solution and the N-N'-diisopropyldiimine (DIC) / DMF mixed solution is 10 min.

5. The method for preparing carbon dioxide responsive organic nanotubes according to claim 1, characterized in that: In step 4, the amount of 4-p-bromobenzylamine solution used is 1.5 mL, the concentration is 0.6 mol / L, and the shaking time after adding the 4-p-bromobenzylamine solution is 15 min.

6. The method for preparing carbon dioxide responsive organic nanotubes according to claim 1, characterized in that: In step 7, the amount of ethylenediamine solution used is 1.5 mL, the concentration is 0.6 mol / L, the shaking time after adding the ethylenediamine solution is 2 h, and the reaction temperature is 40° C.

7. The method for preparing carbon dioxide responsive organic nanotubes according to claim 1, characterized in that: In step eight, the amount of bromoacetic acid used is 1.5 mL, and the amount of N-N'-diisopropyl diimine (DIC) / DMF mixed solution added is 0.8 mL, wherein the concentration of the bromoacetic acid solution is 1.2 mol / L, the volume ratio of N-N'-diisopropyl diimine solution and DMF solution in the N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 1: 1, and the shaking time after adding the bromoacetic acid solution and N-N'-diisopropyl diimine (DIC) / DMF mixed solution is 15min.

8. The method for preparing carbon dioxide responsive organic nanotubes according to claim 1, characterized in that: In step nine, the amount of 2-methoxyethylamine solution used is 1.5 mL, the concentration is 1.2 mol / L, and the shaking time after adding the 2-methoxyethylamine solution is 20 min.

9. The method for preparing carbon dioxide responsive organic nanotubes according to claim 1, characterized in that: In step ten, the amount of chloroacetic acid is 1.5 mL, and the amount of N-N'-diisopropyl diimide (DIC) / DMF mixed solution added is 0.8 mL, wherein the concentration of the chloroacetic acid solution is 1.2 mol / L, the volume ratio of N-N'-diisopropyl diimide solution and DMF solution in the N-N'-diisopropyl diimide (DIC) / DMF mixed solution is 1:1, and the shaking time after adding the chloroacetic acid solution and the N-N'-diisopropyl diimide (DIC) / DMF mixed solution is 20 min; in step eleven, the amount of histamine solution is 1.5 mL, the concentration is 1.2 mol / L, and the shaking time after adding the histamine solution is 1 d.

10. The method for preparing carbon dioxide responsive organic nanotubes according to claim 1, characterized in that: In step twelve, the volume ratio of pure water and trifluoroacetic acid added to product K is 5:95, the stirring time is 20 minutes, the temperature is 40°C, and the storage temperature of the peptoid product is 0°C. In step twelve, the peptoid product is dissolved in a mixture of pure water and tetrahydrofuran in a volume ratio of 1:1, the concentration of the peptoid solution is 2 μmol / L, and the evaporation temperature is 4°C.

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