Two-dimensional cyclodextrin polymer material as well as preparation method and application thereof

Abstract

The invention provides a two-dimensional cyclodextrin polymer material as well as a preparation method and application thereof. The two-dimensional cyclodextrin polymer material is prepared by a method comprising the following steps: stirring a self-assembly agent and cyclodextrin molecules in a solvent, standing, and carrying out self-assembly to form a dispersion liquid with a sheet structure crystal; and mixing the dispersion liquid with a cross-linking agent, reacting, carrying out solid-liquid separation, washing and drying to obtain the product. The method is simple and convenient in preparation process, the two-dimensional cyclodextrin polymer with monomolecular layer thickness is obtained, and the method has considerable industrial application prospects. The invention also provides a two-dimensional cyclodextrin polymer material and application thereof.

Description

Technical Field

[0001] This application relates to the technical field of polymer materials, and particularly relates to a two-dimensional cyclodextrin polymer material, a preparation method thereof, and an application thereof. Background Art

[0002] Two-dimensional polymer materials are one of the forefront research directions in the current field of materials science. Existing research has shown that by preparing two-dimensional oriented materials, comprehensive properties significantly superior to those of traditional one-dimensional materials can be obtained. For example, two-dimensional polyaramide constructs a two-dimensional network molecule through monomer polycondensation, and its molecular layers are stacked into a highly oriented thin film material with a certain thickness through hydrogen bond interactions. In theoretical simulations, this material exhibits extremely high mechanical properties, with a tensile modulus as high as 260 GPa and a strength upper limit of 12 GPa, far exceeding traditional one-dimensional polymer materials. In addition, two-dimensional polymers also have advantages such as low cost and low process threshold, providing a new approach for constructing lightweight and high-strength functional materials.

[0003] Since cyclodextrin was discovered at the end of the 19th century, due to its unique "hydrophobic inside and hydrophilic outside" structure, it has gradually become a research hotspot in supramolecular chemistry and materials science. In recent years, with the development of nanotechnology, bioengineering, and green chemistry, cyclodextrin functional materials have shown great application potential in fields such as drug delivery, environmental governance, separation and purification, and catalysis. However, traditional cyclodextrin materials have deficiencies such as poor stability and low mechanical strength, which limit their wide application. To overcome these deficiencies, constructing cyclodextrin into polymer materials has become a research hotspot. Cyclodextrin polymer is a polymer material formed by connecting multiple cyclodextrin molecules through covalent bonds. It not only retains the inclusion, slow-release, and catalytic properties of cyclodextrin molecules but also has good mechanical strength and chemical stability of polymers, and also has significant improvement in solubility and other aspects. For example, in practical applications, compared with a single cyclodextrin molecule, cyclodextrin polymer in applications that require shaping and processing, such as preparing microspheres and membrane materials, its good mechanical strength can ensure the shape stability and use performance of the material. When preparing drug-loaded slow-release microspheres, cyclodextrin polymer microspheres can maintain the structural integrity in the body and achieve slow release of drugs. Therefore, in fields such as molecular recognition and adsorption, drug carrier and slow release, environmental protection, and catalysis, cyclodextrin polymers all show their great development potential.

[0004] However, limited by the molecular structure of cyclodextrin itself, the current research on cyclodextrin polymers is still limited to one-dimensional polymer structures and is difficult to connect with the forefront research of two-dimensional materials. There are many challenges in realizing two-dimensional polymerization of cyclodextrin. For example, cyclodextrin itself has a cyclic structure and is not easy to extend on a two-dimensional plane. During polymerization, a three-dimensional network structure may be formed instead of a two-dimensional plane structure, resulting in three-dimensional stacking or disordered crosslinking. Therefore, developing a two-dimensional polymerization method suitable for cyclodextrin molecules has become a cutting-edge technology urgently needed in the new material field. Summary of the Invention

[0005] The present application provides a method for preparing a two-dimensional cyclodextrin polymer material, and a two-dimensional cyclodextrin polymer with a single molecular layer thickness is obtained. Based on the nano-scale effect brought about by the optimization of the microstructure of the product, it is expected to improve the comprehensive application performance of the cyclodextrin material. This method has a simple process flow, low cost, good universality, can achieve large-scale industrial production, and has broad industrial application prospects.

[0006] The present application also provides a two-dimensional cyclodextrin polymer material.

[0007] The present application also provides the application of the above two-dimensional cyclodextrin polymer material.

[0008] The first aspect of the present invention relates to a method for preparing a two-dimensional cyclodextrin polymer material, which includes the following steps: Stir and stand a self-assembling agent and cyclodextrin molecules in a solvent to form a dispersion of crystals with a sheet structure by self-assembly; mix the dispersion with a cross-linking agent, react, separate solid from liquid, wash, and dry to obtain the two-dimensional cyclodextrin polymer material; Wherein, the self-assembling agent includes a surfactant with a C10-C30 hydrophobic chain, and the molar ratio of the surfactant to cyclodextrin molecules is ≤1:0.95.

[0009] The method for preparing a two-dimensional cyclodextrin polymer material according to the first aspect of the present invention has at least the following beneficial effects: By using a self-assembling agent to induce the self-assembly of cyclodextrin molecules in a solvent to form a highly ordered single molecular layer lamellar structure, and combining with subsequent cross-linking reactions, a two-dimensional cyclodextrin polymer material with a single molecular layer thickness is prepared, breaking through the technical bottleneck that it is difficult to construct a two-dimensional regular structure due to the ring structure limitation of cyclodextrin molecules in traditional technologies. In the formed two-dimensional cyclodextrin polymer, all cyclodextrin molecules are in the same plane and are directly or indirectly connected by covalent bonds to form an ordered planar structure, and the molecular layer thickness is controlled within 0.7-1 nm, obtaining a two-dimensional polymer material with high regularity and controllable thickness.

[0010] The carbon number range of the hydrophobic chain of the self-assembling agent plays a key regulatory role in the formation of the cyclodextrin single molecular layer lamellar structure. An appropriate carbon number can provide effective spatial configuration constraints, induce the ordered arrangement of cyclodextrin molecules along the plane, and promote the construction of a stable single molecular layer lamella. If the carbon number is too small, it is difficult to effectively induce two-dimensional arrangement and an ordered single molecular layer structure cannot be formed; if the carbon number is too large, the order of two-dimensional arrangement may be reduced. In addition, when the molar ratio of the self-assembling agent to cyclodextrin molecules is too high, it will cause changes in the spatial configuration of supramolecular self-assembly and it is difficult to form a two-dimensional crystal structure.

[0011] This method has wide applicability and is applicable to various cyclodextrin molecules and their derivatives. The prepared materials have a large specific surface area, a uniform lamellar structure, and controllable molecular arrangement characteristics, which help to fully exert the application potential and performance advantages of cyclodextrin materials.

[0012] This method has a simple process and low cost, can achieve large-scale industrial production, and has significant application prospects.

[0013] Among them, the self-assembly agent includes a non-ionic surfactant with 10 to 30 carbon atoms, and / or an ionic surfactant with a C10-C30 hydrophobic chain.

[0014] Specifically, the ionic surfactant includes one or more of anionic (R-X), cationic (R-Y), and zwitterionic surfactants (Y-R-X), where R is a C10-C30 hydrocarbon group or a C10-C30 hetero-hydrocarbon group (hydrophobic chain), X is an anionic hydrophilic group, and Y is a cationic hydrophilic group. For example, anionic hydrophilic groups include, but are not limited to, carboxyl group, carboxylate group, sulfonic acid group, sulfonate group, benzenesulfonic acid group, benzenesulfonate group, sulfate group, sulfate ester group, etc.; cationic hydrophilic groups include, but are not limited to, ammonium salt group, C1-C12 alkylamine salt group, etc.

[0015] More specifically, typical and non-limiting examples of non-ionic surfactants include sorbitan monooleate, coconut glucoside; typical and non-limiting examples of cationic surfactants include cetyltrimethylammonium bromide, tetradecyltrimethylammonium chloride; typical and non-limiting examples of anionic surfactants include sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, N-lauroyl glycine; typical and non-limiting examples of zwitterionic surfactants include coconut amide propyl betaine.

[0016] According to some embodiments of the present invention, the self-assembly agent includes a surfactant with a C10-C20 hydrophobic chain, such as a non-ionic surfactant with 10 to 20 carbon atoms, and / or an ionic surfactant with a C10-C20 hydrophobic chain.

[0017] According to some embodiments of the present invention, the cyclodextrin molecule is a cyclic structure formed by connecting more than 3 monosaccharide units through glycosidic bonds, and the monosaccharide units are selected from one or more of triose, tetrose, pentose, hexose, heptose or their derivatives.

[0018] For example, common cyclodextrin derivatives include cyclodextrins modified with one or more of the following functional groups: C1-C30 alkyl groups (such as methyl, ethyl), hydroxypropyl groups, hydroxyl groups, amino groups, mercapto groups, carboxyl groups, carboxylate groups, aldehyde groups, C1-C30 hydrocarbyl ether groups, sulfonic acid groups, sulfonate groups, sulfonyl groups, benzenesulfonic acid groups, benzenesulfonate groups, azide groups, silyl groups, phosphate esters or their salts, nitro groups, C1-C30 hydrocarbyl ester groups, dipeptide groups (such as aspartame modification groups), tripeptide groups (such as glutathione modification groups), cyano groups, and halogens, where the number of functional groups ranges from single substitution to the maximum number of substitutions.

[0019] According to some embodiments of the present invention, the cyclodextrin molecule is selected from one or more of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, or their derivatives. The basic monosaccharide units of the above cyclodextrin molecules are all hexoses (i.e., glucose), and the most common ones are molecules containing 6, 7, or 8 glucose units, which are respectively called α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. These types of cyclodextrins and their derivatives are easily obtained through commercial channels. In addition, other cyclodextrin molecules containing more than 3 glucose units can also be synthesized using techniques known in the art, and the common degree of polymerization is 3-13 monosaccharide units.

[0020] According to some embodiments of the present invention, the molar ratio of the surfactant to the cyclodextrin molecule is 1:0.95-12, for example, 1:0.95, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, or 1:12.

[0021] According to some specific embodiments of the present invention, the molar ratio of the surfactant to the cyclodextrin molecule is 1:0.95-8.

[0022] According to some embodiments of the present invention, the crosslinking agent is selected from one or more of acyl chloride compounds, acid anhydride compounds, isocyanate compounds, haloalkane compounds, halosilane compounds, epoxy group silane compounds, amino group silane compounds, haloepoxy compounds, aldehyde compounds, ester compounds, glycidyl ether compounds, halotriazine compounds, nitrile compounds, organic acids or their salts, organic bases or their salts, unsaturated hydrocarbon compounds, polyhydroxy polymers, polycarbonates, fluorinated polyolefins, and acrylic modified polymers, and the crosslinking agent has multiple functional groups capable of reacting with the cyclodextrin molecule. The crosslinking agent is known in the art and is a substance capable of reacting with the cyclodextrin molecule, not limited to the listed types.

[0023] Specifically, the crosslinking agent includes but is not limited to the following substances: acyl chloride compounds such as glutaroyl chloride, adipoyl chloride, sebacoyl chloride, terephthaloyl chloride, succinyl chloride; anhydride compounds such as glutaric anhydride, maleic anhydride, succinic anhydride, phthalic anhydride, pyromellitic dianhydride; isocyanate compounds such as hexamethylene diisocyanate, isophorone diisocyanate, poly diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-dicyclohexyl diisocyanate, 4,4'-diphenylmethane diisocyanate, triphenylmethane - 4,4',4''-triisocyanate; haloalkane compounds such as dichloromethane; halosilane compounds such as dichlorodimethylsiloxane; epoxy group silane compounds such as 3-(2,3-epoxypropoxy)propyltrimethoxysilane; aminosilane compounds such as γ-aminopropyltriethoxysilane; haloepoxy compounds such as epichlorohydrin; aldehyde compounds such as glutaraldehyde; ester compounds such as diphenyl carbonate; glycidyl ether compounds such as 1,4-butanediol diglycidyl ether; halotriazine compounds such as trichlorotriazine; nitrile compounds such as tetrafluoroterephthalonitrile; organic acids or their salts such as citric acid, glutamic acid, malic acid, tartaric acid, mucic acid, maleic acid, glutaric acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, tricarboxylic acid, trimellitic acid, 2,6-naphthalenedicarboxylic acid, aspartic acid, tetrafluoroterephthalic acid, sodium citrate; organic bases such as hexamethylenediamine; unsaturated hydrocarbon compounds such as 1,4-diethynylbenzene; polyhydroxy polymers such as polyethylene glycol, polyvinyl alcohol; polycarbonates such as poly(propylene carbonate); fluorinated polyolefins such as poly(vinylidene fluoride), polytetrafluoroethylene; acrylic acid modified polymers such as polyethylene glycol monoacrylate, polycyanoacrylate.

[0024] According to some embodiments of the present invention, the molar ratio of the crosslinking agent to the cyclodextrin molecule is 2 - 50:1, for example, it can be 2:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, so as to form a moderate crosslinked structure.

[0025] According to some specific embodiments of the present invention, the molar ratio of the crosslinking agent to the cyclodextrin molecule is 2 - 30:1, or 2 - 20:1, or 2 - 10:1.

[0026] According to some embodiments of the present invention, the solvent is selected from at least one of water, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, isopropyl alcohol, chloroform, tetrahydrofuran, trifluoroacetic acid.

[0027] According to some embodiments of the present invention, the addition amount of the surfactant relative to the solvent is 1 - 600 mg / mL, such as 5 - 500 mg / mL, or 5 - 300 mg / mL, or 5 - 100 mg / mL, or 5 - 80 mg / mL, more specifically 5 mg / mL, 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, 50 mg / mL, 60 mg / mL, 70 mg / mL or 80 mg / mL.

[0028] According to some embodiments of the present invention, the addition amount of the cyclodextrin molecule relative to the solvent is 1 - 2000 mg / mL, or 10 - 1000 mg / mL, or 10 - 800 mg / mL, or 10 - 700 mg / mL, or 10 - 500 mg / mL, more specifically 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, 50 mg / mL, 100 mg / mL, 150 mg / mL, 200 mg / mL, 250 mg / mL, 300 mg / mL, 350 mg / mL, 400 mg / mL, 450 mg / mL, 500 mg / mL.

[0029] According to some embodiments of the present invention, the temperature of stirring is 20 - 100 °C, and the temperature of standing is lower than the temperature of stirring. For example, the temperature of stirring can be 40 - 90 °C, and the temperature of standing can be 20 - 30 °C. The present invention does not strictly limit the specific temperature and time of stirring and standing, and can be adjusted according to the solubility of the sample or the processing amount. The stirring time can be several hours or dozens of hours to obtain a fully uniform mixing effect; the standing time can be appropriately adjusted according to the volume of the treatment solution. When the processing amount is small, it can be several minutes, and when the processing amount reaches more than 0.5 L, it can be extended to dozens of hours or even more than 2 weeks until self-assembled crystals are stably formed in the system.

[0030] According to some embodiments of the present invention, it further includes the step of adding a catalyst and mixing before the reaction. The use of the catalyst can be flexibly selected according to the reaction activity between the crosslinking agent and the cyclodextrin molecule. Its reaction mechanism is a known technology, and the specific type and dosage can be reasonably selected according to experience. For example, the catalyst can be selected from inorganic salts, including but not limited to sodium dihydrogen phosphate, sodium bicarbonate, potassium bicarbonate, potassium dihydrogen phosphate, sodium bisulfite, potassium hydrogen oxalate, sodium hydrosulfide, sodium borohydride, ammonium hydrosulfide, etc., and the dosage can be 5% - 15% of the molar dosage of the crosslinking agent. For some crosslinking systems with relatively high reaction activity, rapid reaction can be achieved without a catalyst, improving the simplicity of the process.

[0031] According to some embodiments of the present invention, the temperature of the reaction is 20 - 150 °C, which can be adjusted according to the reactivity of the system. When the reactivity is high, a lower reaction temperature can be adopted and the reaction time can be shortened, and even a rapid reaction can be achieved during mixing; when the reactivity is low, a higher reaction temperature and an extended reaction time are required. For example, the reaction can be carried out at a temperature above 100 °C for several hours to ensure a complete reaction. When the reaction temperature exceeds the boiling point or flash point of the solvent used, reflux treatment is carried out during the reaction process.

[0032] According to some embodiments of the present invention, the solid-liquid separation is carried out by any one of centrifugation, vacuum filtration, screen filtration, gauze filtration or natural sedimentation.

[0033] According to some embodiments of the present invention, the drying is carried out by any one of heating and drying, natural air drying, spray drying, vacuum drying, freeze drying or supercritical drying.

[0034] According to some embodiments of the present invention, the washing is carried out with water.

[0035] The second aspect of the embodiments of the present invention relates to a two-dimensional cyclodextrin polymer material having a layered structure, wherein the layered structure is a planar structure formed by covalent bonding of cyclodextrin molecules, and the thickness of the layered structure is 0.7 - 1 nm, and the sheet diameter is ≥ 10 nm.

[0036] In this two-dimensional cyclodextrin polymer, all cyclodextrin molecules are in the same plane and are directly or indirectly connected by covalent bonds to form an ordered planar structure. The thickness of the molecular layer is controlled within 0.7 - 1 nm, and a two-dimensional polymer material with a highly regular and controllable thickness is obtained. This material has a large specific surface area, a uniform sheet structure and the characteristics of controllable molecular arrangement, which helps to fully exert the performance advantages of the cyclodextrin material. This material can be prepared by a simple method, which is convenient for large-scale application.

[0037] Among them, the type of cyclodextrin molecule can be determined with reference to the embodiments of the foregoing preparation method.

[0038] According to some embodiments of the present invention, the two-dimensional cyclodextrin polymer material satisfies at least one of the following conditions: (1) The sheet diameter is 10 nm - 100 μm; (2) The layered structure includes a pore structure, and the pore structure includes one or more of micropores, mesopores and macropores, wherein the pore diameter of the micropores is less than 2 nm, the pore diameter of the mesopores is 2 - 50 nm, and the pore diameter of the macropores is greater than 50 nm.

[0039] According to some specific embodiments of the present invention, the pore diameter of the micropores is more than 0.5 nm and less than 2 nm, and the pore diameter of the macropores is 50 - 500 nm.

[0040] The third aspect embodiment of the present invention relates to the two-dimensional cyclodextrin polymer material prepared by the above-mentioned preparation method, or the application of the above-mentioned two-dimensional cyclodextrin polymer material in the fields of catalysts, functional bulk materials, drug delivery, gene transportation, substance separation or purification, and pollutant adsorption or removal.

[0041] Specifically, in the field of catalysts, it can be used as a stable carrier for metal ions, chiral centers or enzyme factors, and applied in aspects such as asymmetric catalysis, aqueous-phase reactions and biomimetic catalysis. At the same time, this material can also be used as a functional bulk material, for example, to prepare aerogels, etc.

[0042] In the drug delivery system, it is particularly suitable for aspects such as solubilization and encapsulation of poorly water-soluble drugs, sustained-release and controlled-release preparations, targeted delivery systems, improvement of local permeability, and stable release of protein drugs. In the field of gene transportation, it can be used for aspects such as efficient encapsulation and transfection of plasmid DNA, siRNA or miRNA. In the field of separation and purification, it is suitable for aspects such as chiral compound resolution, drug metabolite capture, chromatographic stationary phases or functional membrane materials. As a membrane material, it can separate and purify liquid and gas molecules of different sizes, and at the same time play an isolation role. In the field of pollutant adsorption and removal, the two-dimensional structure helps to expose more active sites, improve the enrichment ability for organic dyes, heavy metal ions, microplastics and radionuclides, etc., and is suitable for various application scenarios such as environmental remediation.

[0043] In this article, the term "hydrophobic chain" refers to a molecular chain with hydrophobic properties, including hydrocarbon groups or hetero-hydrocarbon groups, and its structure can be a straight-chain, branched-chain, cyclic structure, or a combination of at least two of these structures.

[0044] The term "hydrocarbon group" refers to a group composed only of carbon and hydrogen atoms, including saturated hydrocarbon groups (such as straight-chain or branched-chain alkyl groups, alkyl-substituted or unsubstituted cycloalkyl groups), unsaturated non-aromatic hydrocarbon groups (such as alkenyl groups, alkynyl groups) and aromatic hydrocarbon groups (such as phenyl groups, naphthyl groups, biphenyl groups, etc.). "Hetero-hydrocarbon group" refers to the hydrocarbon groups defined above, where at least one carbon atom is replaced by a non-carbon atom, and the non-carbon atom can be selected from at least one of O, S, N, Se, Si or Ge, but does not include the case where the non-carbon atom is used as a connection site (such as alkoxy groups, aryloxy groups, alkylamino groups, arylamino groups, etc.).

[0045] The term "a variety of" means two or more.

[0046] The terms "above" and "below" both include the numerical value itself. Relatively speaking, "lower than", "greater than" and "less than" do not include the numerical value itself.

[0047] "About" means that the error range is mainly within ±5%.

[0048] "Room temperature" means 23 ± 2 °C.

[0049] In this article, the numerical ranges involved all include the endpoint values and cover any sub-ranges within the range, such as the ranges obtained by any combination of the specifically listed numerical values. Description of the Drawings

[0050] Figure 1 is the aberration-corrected transmission electron microscope image (left) of the self-assembled crystal in Example 1 and its selected area electron diffraction spot pattern (right).

[0051] Figure 2 is the photograph (left) of the two-dimensional cyclodextrin polymer powder in Example 1 and its transmission electron microscope image (right, scale bar 100 nm).

[0052] Figure 3 is the atomic force microscope image of the two-dimensional cyclodextrin polymer monolayer in Example 1.

[0053] Figure 4 is the BET pore size test result diagram of the two-dimensional cyclodextrin polymer in Example 1. Detailed Description of the Invention

[0054] The following are specific examples of the present invention, and the technical solutions of the present invention are further described in combination with the examples, but the present invention is not limited to these examples.

[0055] The description of some raw materials is as follows: α-cyclodextrin, CAS No.: 10016-20-3.

[0056] β-cyclodextrin, CAS No.: 7585-39-9.

[0057] γ-cyclodextrin, CAS No.: 17465-86-0.

[0058] 6-amino-6-deoxy-β-cyclodextrin, CAS No.: 29390-67-8.

[0059] 6-mercapto-6-deoxy-β-cyclodextrin, CAS No.: 81644-55-5.

[0060] Heptakis substituted sulfobutyl ether-β-cyclodextrin, CAS No.: 165133-56-2.

[0061] Hydroxypropyl-γ-cyclodextrin, CAS No.: 128446-34-4.

[0062] Sodium β-cyclodextrin phosphate monobasic, CAS No.: 199684-61-2.

[0063] Heptakis(6-amino-6-deoxy)-β-cyclodextrin, CAS No.: 30754-24-6.

[0064] Tetradecyltrimethylammonium chloride, CAS No.: 4574-04-3.

[0065] Cetyltrimethylammonium bromide, CAS No.: 57-09-0.

[0066] Sorbitan monooleate, CAS No.: 1338-43-8.

[0067] Cocoyl glucoside, CAS No.: 141464-42-8.

[0068] N-Lauroyl glycine: CAS No.: 7596-88-5.

[0069] Sodium dodecyl sulfate, CAS No.: 151-21-3.

[0070] Sodium dodecylbenzenesulfonate, CAS No.: 25155-30-0.

[0071] For those not specified with specific conditions in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For example, during the reaction process, reflux treatment is carried out to avoid solvent volatilization. For the reagents or instruments not specified with the manufacturer, they are all conventional products that can be obtained by purchasing in the market.

[0072] Example 1 First, 1 gram of cetyltrimethylammonium bromide was dissolved in 100 milliliters of water, and 8 grams of β-cyclodextrin was dissolved in 100 milliliters of water. Then the two were completely mixed and stirred at 80 °C for 12 hours. After stopping stirring, the mixed solution was left standing at 25 °C for 24 hours, and self-assembled crystals were formed in the mixed solution. The characterization results are as Figure 1 shown. The obtained self-assembled crystal mixed solution was mixed with citric acid and sodium dihydrogen phosphate (sodium dihydrogen phosphate was one-tenth of the molar amount of citric acid, and the molar ratio of citric acid to β-cyclodextrin was 2:1). After stirring, a homogeneous system was obtained. After reacting at 140 °C for 4 hours, the obtained solid was centrifugally washed with water multiple times, and after heating and drying, two-dimensional cyclodextrin polymer powder was obtained. The characterization results are as Figures 2 to 4 shown.

[0073] Figure 1 In, the left figure is the aberration-corrected transmission electron microscope picture of the crystal sample, and the right figure is the corresponding selected area electron diffraction spot pattern. From the left figure, uniformly arranged ordered lattice fringes can be observed, indicating that the sample has a highly ordered crystal structure. The right figure shows a regular and clear single crystal diffraction spot array, confirming that the sample is a single crystal structure. Through comprehensive analysis, it can be inferred that a monolayer crystal structure was obtained.

[0074] From Figure 2It can be seen from the TEM image that the obtained material has a thin-layer structure, and the sheet diameter is mainly distributed in the range of 30 nm to 1 μm. Figure 3 The AFM test results show that the sheet thickness of this material is about 0.8 nm, which is consistent with the molecular height of β-cyclodextrin molecules along the direction perpendicular to the toroidal plane, indicating that this material has a single-molecular-layer two-dimensional structure. Figure 4 The pore size test results show that this material has a microporous structure, and the pore size is mainly concentrated at about 1.5 nm, and the pore size distribution is concentrated and uniform. This structure can be applied to separation and purification and isolation of ions, liquids, and gas molecules with molecular sizes different from those bounded by 1.5 nm.

[0075] Example 2 First, dissolve 5 grams of cetyltrimethylammonium bromide in 100 milliliters of water, dissolve 50 grams of β-cyclodextrin in 100 milliliters of water, then mix the two completely, and stir at 60 °C for 24 hours. After stopping stirring, let the mixed solution stand at 25 °C for 48 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixed solution with glutamic acid and sodium dihydrogen phosphate (sodium dihydrogen phosphate is one-tenth of the molar amount of glutamic acid, and the molar ratio of glutamic acid to β-cyclodextrin is 2:1), stir to obtain a homogeneous system, react at 140 °C for 4 hours, then wash the obtained solid by centrifugation with water for multiple times, and obtain two-dimensional cyclodextrin polymer powder after heating and drying.

[0076] Example 3 First, dissolve 5 grams of cetyltrimethylammonium bromide in 100 milliliters of water, dissolve 50 grams of α-cyclodextrin in 100 milliliters of water, then mix the two completely, and stir at 80 °C for 14 hours. After stopping stirring, let the mixed solution stand at 20 °C for 24 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixed solution with malic acid and potassium bicarbonate (potassium bicarbonate is one-tenth of the molar amount of malic acid, and the molar ratio of malic acid to α-cyclodextrin is 2:1), stir to obtain a homogeneous system, react at 140 °C for 3.5 hours, then wash the obtained solid by centrifugation with ethanol for multiple times, and obtain two-dimensional cyclodextrin polymer powder after vacuum drying.

[0077] Example 4 First, dissolve 50 grams of tetradecyltrimethylammonium chloride in 1 liter of water, and dissolve 500 grams of γ-cyclodextrin in 800 milliliters of water. Then mix the two completely and stir at 80 °C for 28 hours. After stopping the stirring, let the mixed solution stand at 25 °C for 48 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixed solution with tartaric acid and potassium dihydrogen phosphate (potassium dihydrogen phosphate is one-tenth of the molar amount of tartaric acid, and the molar ratio of tartaric acid to γ-cyclodextrin is 2:1). After stirring to obtain a homogeneous system, react at 135 °C for 5 hours, and then wash the obtained solid with water by centrifugation for multiple times. After freeze-drying, a two-dimensional cyclodextrin polymer powder is obtained.

[0078] Example 5 First, dissolve 8 grams of sodium dodecyl sulfate in 100 milliliters of water, and dissolve 30 grams of β-cyclodextrin in 100 milliliters of water. Then mix the two completely and stir at 80 °C for 24 hours. After stopping the stirring, let the mixed solution stand at 25 °C for 24 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixed solution with muconic acid and sodium bisulfite (sodium bisulfite is one-tenth of the molar amount of muconic acid, and the molar ratio of muconic acid to β-cyclodextrin is 2:1). After stirring to obtain a homogeneous system, react at 145 °C for 4.5 hours, and then wash the obtained solid with water and ethanol by vacuum filtration for multiple times. After natural air drying, a two-dimensional cyclodextrin polymer powder is obtained.

[0079] Example 6 First, dissolve 100 grams of sodium dodecylbenzenesulfonate in 1 liter of water, and dissolve 400 grams of 6-amino-6-deoxy-β-cyclodextrin in 1 liter of water. Then mix the two completely and stir at 80 °C for 12 hours. After stopping the stirring, let the mixed solution stand at 25 °C for 72 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixed solution with aspartic acid and potassium hydrogen oxalate (potassium hydrogen oxalate is one-tenth of the molar amount of aspartic acid, and the molar ratio of aspartic acid to 6-amino-6-deoxy-β-cyclodextrin is 2:1). After stirring to obtain a homogeneous system, react at 130 °C for 5 hours, and then wash the obtained solid with water and isopropyl alcohol by centrifugation for multiple times. After heating and drying, a two-dimensional cyclodextrin polymer powder is obtained.

[0080] Example 7 First, dissolve 8 g of sodium dodecylbenzenesulfonate in 100 mL of water, and dissolve 30 g of 6-mercapto-6-deoxy-β-cyclodextrin in 100 mL of water. Then mix the two completely and stir at 60 °C for 24 hours. After stopping the stirring, let the mixed solution stand at 30 °C for 96 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixture with tricarballylic acid and sodium bicarbonate (sodium bicarbonate is one-tenth of the molar amount of tricarballylic acid, and the molar ratio of tricarballylic acid to 6-mercapto-6-deoxy-β-cyclodextrin is 2:1). After stirring to obtain a homogeneous system, react at 150 °C for 3 hours. Then, wash the obtained solid with water by centrifugation for multiple times, and obtain two-dimensional cyclodextrin polymer powder after heating and drying.

[0081] Example 8 First, dissolve 15 g of sorbitan monooleate in 100 mL of water, and dissolve 50 g of heptakis (2-sulfoethyl)-β-cyclodextrin in 100 mL of water. Then mix the two completely and stir at 60 °C for 24 hours. After stopping the stirring, let the mixed solution stand at 25 °C for 72 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixture with trimesic acid and sodium hydrosulfide (sodium hydrosulfide is one-tenth of the molar amount of trimesic acid, and the molar ratio of trimesic acid to heptakis (2-sulfoethyl)-β-cyclodextrin is 2:1). After stirring to obtain a homogeneous system, react at 140 °C for 4 hours. Then, wash the obtained solid with water by centrifugation for multiple times, and obtain two-dimensional cyclodextrin polymer powder after heating and drying.

[0082] Example 9 First, dissolve 6 g of N-lauroylglycine in 100 mL of water, and dissolve 60 g of hydroxypropyl-γ-cyclodextrin in 100 mL of water. Then mix the two completely and stir at 60 °C for 24 hours. After stopping the stirring, let the mixed solution stand at 25 °C for 72 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixture with 2,6-naphthalenedicarboxylic acid and sodium borohydride (sodium borohydride is one-tenth of the molar amount of 2,6-naphthalenedicarboxylic acid, and the molar ratio of 2,6-naphthalenedicarboxylic acid to hydroxypropyl-γ-cyclodextrin is 2:1). After stirring to obtain a homogeneous system, react at 140 °C for 3 hours. Then, wash the obtained solid with water by centrifugation for multiple times, and obtain two-dimensional cyclodextrin polymer powder after heating and drying.

[0083] Example 10 First, dissolve 5 g of coconut oil-based glucoside in 100 mL of water, and dissolve 50 g of sodium dihydrogen phosphate ester of β-cyclodextrin in 100 mL of water. Then mix the two completely and stir at 60 °C for 24 hours. After stopping the stirring, let the mixed solution stand at 25 °C for 72 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixture with tetrafluoroterephthalic acid and ammonium hydrosulfide (ammonium hydrosulfide is one-tenth of the molar amount of tetrafluoroterephthalic acid, and the molar ratio of tetrafluoroterephthalic acid to sodium dihydrogen phosphate ester of β-cyclodextrin is 2:1), stir to obtain a homogeneous system, react at 140 °C for 3 hours, then wash the obtained solid with water by centrifugation for multiple times, and obtain two-dimensional cyclodextrin polymer powder after heating and drying.

[0084] Example 11 First, dissolve 10 g of cetyltrimethylammonium bromide in 300 mL of water, and dissolve 50 g of hepta(6-amino-6-deoxy)-β-cyclodextrin in 200 mL of water. Then mix the two completely and stir at 90 °C for 24 hours. After stopping the stirring, let the mixed solution stand at 20 °C for 240 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixture with glutamic acid and sodium dihydrogen phosphate (sodium dihydrogen phosphate is one-tenth of the molar amount of glutamic acid, and the molar ratio of glutamic acid to hepta(6-amino-6-deoxy)-β-cyclodextrin is 2:1), stir to obtain a homogeneous system, react at 140 °C for 4 hours, then wash the obtained solid with water by centrifugation for multiple times, and obtain two-dimensional cyclodextrin polymer powder after heating and drying.

[0085] Example 12 First, dissolve 8 g of sodium dodecyl sulfate in a mixed solution of 50 mL of water and 50 mL of ethanol, and dissolve 30 g of β-cyclodextrin in 100 mL of water. Then mix the two completely and stir at 80 °C for 24 hours. After stopping the stirring, let the mixed solution stand at 25 °C for 24 hours, and self-assembled crystals are formed in the mixed solution. Mix the obtained self-assembled crystal mixture with glutaraldehyde (the molar ratio of glutaraldehyde to β-cyclodextrin is 2:1) at room temperature, stir to obtain a homogeneous system, wash the obtained solid with water by centrifugation for multiple times, and obtain two-dimensional cyclodextrin polymer powder after heating and drying.

[0086] Examples 2-12 can also prepare two-dimensional cyclodextrin polymer powder with a monolayer structure, and its lamellar morphology is similar to that of Example 1. In actual operation, the product sample can be dispersed (by mechanical stirring or ultrasonic treatment, etc.) in a solvent (such as water), and a uniformly dispersed monolayer structure can be easily obtained.

[0087] Comparative Example 1 Dissolve 8 g of β-cyclodextrin in 100 mL of water, stir at 80 °C for 12 h, add citric acid and sodium dihydrogen phosphate for mixing (sodium dihydrogen phosphate is one-tenth of the molar amount of citric acid, and the molar ratio of citric acid to β-cyclodextrin is 2:1), stir to obtain a homogeneous system, react at 140 °C for 4 h, then wash the obtained solid with water by centrifugation for multiple times, and obtain cyclodextrin polymer powder after heating and drying. It presents a three-dimensional disordered cross-linked structure and does not have a two-dimensional structure.

[0088] Comparative Example 2 Dissolve 1 g of octyltrimethylammonium bromide in 100 mL of water, dissolve 8 g of β-cyclodextrin in 100 mL of water, then mix the two completely, and stir at 80 °C for 12 h. After stopping stirring, let the mixed solution stand at 25 °C for 24 h, and no self-assembled crystals are produced.

[0089] Comparative Example 3 First, dissolve 1 g of sodium dodecyl sulfate in 100 mL of water, dissolve 8 g of β-cyclodextrin in 100 mL of water, then mix the two completely, immediately add terephthalic acid and sodium dihydrogen phosphate (sodium dihydrogen phosphate is one-tenth of the molar amount of terephthalic acid, and the molar ratio of terephthalic acid to β-cyclodextrin is 2:1), react at 140 °C for 4 h, and the obtained solid product is a cyclodextrin polymer with a three-dimensional cross-linked structure.

[0090] Comparative Example 4 First, dissolve 3 g of cetyltrimethylammonium bromide in 100 mL of water, dissolve 8 g of β-cyclodextrin in 100 mL of water, then mix the two completely, and stir at 80 °C for 12 h. After stopping stirring, let the mixed solution stand at 25 °C for 24 h, and no self-assembled crystals are produced in the mixed solution.

[0091] By comparing Comparative Examples 1, 2 and 4, it can be seen that in the case of not adding a surfactant, the surfactant having a short hydrophobic chain length or the surfactant having too high a proportion relative to cyclodextrin, it is difficult for cyclodextrin molecules to form an ordered two-dimensional lamellar structure in the solution, and thus it is difficult to prepare a two-dimensional layered material through a cross-linking reaction. Comparative Example 3 shows that the lack of a sufficient stirring and standing process may make it difficult to induce the formation of a self-assembled crystal structure, and thus a two-dimensional layered material cannot be obtained.

[0092] The present invention has been described in detail above in combination with the embodiments, but the present invention is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art to which the present invention pertains, various changes can also be made without departing from the gist of the present invention.

Claims

1. A method for preparing a two-dimensional cyclodextrin polymer material, characterized in that: The steps include: The self-assembling agent and cyclodextrin molecules are stirred in a solvent, and allowed to stand to self-assemble to form a dispersion having a sheet-like structure crystal; The dispersion is mixed with a cross-linking agent, reacted, solid-liquid separated, washed, and dried to obtain the two-dimensional cyclodextrin polymer material; Wherein, the self-assembling agent comprises a surfactant having a C10-C30 hydrophobic chain, and the molar ratio of the surfactant to the cyclodextrin molecule is ≤1:0.

95.

2. The preparation method according to claim 1, characterized in that: The cross-linking agent is selected from one or more of acyl chloride compounds, acid anhydride compounds, isocyanate compounds, halogenated alkane compounds, halogenated silane compounds, epoxy silane compounds, aminosilane compounds, halogenated epoxy compounds, aldehyde compounds, ester compounds, glycidyl ether compounds, halogenated triazine compounds, nitrile compounds, organic acids or salts thereof, organic bases or salts thereof, unsaturated hydrocarbon compounds, polyhydroxy polymers, polycarbonates, fluorinated polyolefins and acrylic acid-modified polymers, and the cross-linking agent has multiple functional groups that can react with the cyclodextrin molecules; And / or, the molar ratio of the cross-linking agent to the cyclodextrin molecules is 2-50:

1.

3. The preparation method according to claim 1, characterized in that: The self-assembling agent comprises a surfactant having a C10-C20 hydrophobic chain; and / or, the molar ratio of the surfactant to the cyclodextrin molecule is 1:0.95-12.

4. The preparation method according to claim 1, characterized in that: The solvent is selected from at least one of water, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, isopropanol, chloroform, tetrahydrofuran, and trifluoroacetic acid; and / or, the amount of the surfactant added relative to the solvent is 1-600 mg / mL; And / or, the amount of the cyclodextrin molecules added to the solvent is 1-2000 mg / mL.

5. The preparation method according to claim 1, characterized in that: The stirring temperature is 20-100°C, and the standing temperature is lower than the stirring temperature; And / or, the method further comprises the step of adding a catalyst and mixing before the reaction.

6. The preparation method according to claim 1, characterized in that: The solid-liquid separation is carried out by centrifugation, vacuum filtration, screen filtration, gauze filtration or natural sedimentation; And / or, the drying is carried out by any one of heating drying, natural air drying, spray drying, vacuum drying, freeze drying or supercritical drying.

7. A two-dimensional cyclodextrin polymer material, characterized in that: The layered structure is a planar structure formed by cyclodextrin molecules connected by covalent bonds. The thickness of the layered structure is 0.7-1 nm, and the sheet diameter is ≥10 nm.

8. The two-dimensional cyclodextrin polymer material according to claim 7, characterized in that: The two-dimensional cyclodextrin polymer material satisfies at least one of the following conditions: (1) The sheet diameter is 10 nm-100 μm; (2) The layered structure comprises a pore structure, and the pore structure comprises one or more of micropores, mesopores and macropores, wherein the pore size of the micropores is less than 2 nm, the pore size of the mesopores is 2-50 nm, and the pore size of the macropores is greater than 50 nm.

9. The two-dimensional cyclodextrin polymer material according to claim 8, characterized in that: The pore diameter of the micropores is greater than 0.5 nm and less than 2 nm, and the pore diameter of the macropores is 50-500 nm.

10. Application of the two-dimensional cyclodextrin polymer material obtained by the preparation method according to any one of claims 1 to 6, or the two-dimensional cyclodextrin polymer material according to any one of claims 7 to 9 in the fields of catalysts, functional block materials, drug delivery, gene transport, material separation or purification, and pollutant adsorption or removal.

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