阅读说明：本技术 环糊精金属有机骨架材料及其制备 (Cyclodextrin metal organic framework material and preparation thereof ) 是由 丁甜 沈默斐 刘东红 陈士国 叶兴乾 胡亚芹 于 2020-02-25 设计创作，主要内容包括：本申请公开环糊精金属有机骨架材料及其制备,环糊精金属有机骨架材料由如下方法制备：将环糊精和碱金属氢氧化物溶于水,得水溶液；将所得水溶液后与溶剂混合,得混合液；对所述混合液进行超声处理,超声处理开始的同时加入表面活性剂,得粗产物；对所述粗产物进行后处理后即得。采用超声辅助并结合表面活性剂,缩短了反应时间、且制备得到的环糊精金属有机骨架材料粒径均一规整,有良好的几何外型。(The application discloses a cyclodextrin metal-organic framework material and a preparation method thereof, wherein the cyclodextrin metal-organic framework material is prepared by the following method: dissolving cyclodextrin and alkali metal hydroxide in water to obtain water solution; mixing the obtained water solution with a solvent to obtain a mixed solution; carrying out ultrasonic treatment on the mixed solution, and adding a surfactant at the same time of starting the ultrasonic treatment to obtain a crude product; and carrying out post-treatment on the crude product to obtain the product. The reaction time is shortened by adopting ultrasonic assistance and combining with a surfactant, and the prepared cyclodextrin metal organic framework material has uniform and regular particle size and good geometric appearance.)

1. The cyclodextrin metal-organic framework material is characterized by being prepared by the following method:

dissolving cyclodextrin and alkali metal hydroxide in water to obtain water solution;

mixing the obtained water solution with a solvent to obtain a mixed solution;

carrying out ultrasonic treatment on the mixed solution, and adding a surfactant while carrying out ultrasonic treatment to obtain a crude product;

and carrying out post-treatment on the crude product to obtain the product.

2. The cyclodextrin metal-organic framework material of claim 1, wherein the cyclodextrin is α -cyclodextrin, β -cyclodextrin, γ -cyclodextrin, hydroxypropyl- β -cyclodextrin, sulfobutyl- β -cyclodextrin, methyl- β -cyclodextrin, carboxymethyl- β -cyclodextrin, or a combination of any of them.

3. The cyclodextrin metal-organic framework material of claim 1, wherein the alkali metal hydroxide is at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and francium hydroxide.

4. A cyclodextrin metal-organic framework material according to claim 1, wherein the cyclodextrin is added in an amount of 0.01mmol/m L-0.05 mmol/m L, the alkali metal oxide is added in an amount of 0.1mmol/m L-0.5 mmol/m L, and the volume ratio of the mixture of the aqueous solution and the solvent is 5 (1-5) when the mixed solution is prepared.

5. A cyclodextrin metal organic framework material of claim 1, wherein the solvent is methanol, ethanol, isopropanol, or any combination thereof.

6. A cyclodextrin metal-organic framework material of claim 1, wherein the sonication conditions are: the frequency is 20-22 kHz, the power is 96-768W, and the effective ultrasonic time is 3-60 min.

7. The cyclodextrin metal-organic framework material as claimed in claim 1, wherein the ultrasonic treatment is a batch ultrasonic treatment, and the ultrasonic time is 1-3 s and the batch time is 1-3 s in one cycle of the batch ultrasonic treatment.

8. A cyclodextrin metal organic framework material according to claim 1, wherein the surfactant is polyethylene glycol, povidone, polysorbate, sorbitan monolaurate, polyoxyethylene lauryl ether, nonylphenol polyoxyethylene ether condensate, polyoxyethylene fatty alcohol ether, polyoxyethylene polypropylene glycol condensate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, dodecyldimethylbenzyl ammonium bromide or any combination thereof.

9. A cyclodextrin metal organic framework material according to claim 1, wherein the surfactant is added in an amount of 0.001mmol/m L-0.005 mmol/m L.

10. The preparation method of the cyclodextrin metal-organic framework material is characterized by comprising the following steps:

dissolving cyclodextrin and alkali metal in water to obtain water solution;

mixing the obtained water solution with an organic solvent to obtain a mixed solution;

carrying out ultrasonic treatment on the mixed solution, and adding a surfactant while carrying out ultrasonic treatment to obtain a crude product;

and carrying out post-treatment on the crude product to obtain the product.

Technical Field

The application relates to the technical field of metal organic framework material preparation, in particular to a method for quickly crystallizing a cyclodextrin metal organic framework material under the assistance of ultrasonic waves and a product thereof.

Background

Metal-Organic Frameworks (MOFs) are porous coordination materials composed of multidentate Organic ligands and Metal ions or Metal clusters, and are infinite network structures formed by coordination bonds or covalent bonds between the centers of Metal ions and Organic ligands. The porous material has the advantages of large specific surface area, adjustable function, high porosity and the like, is a novel rapidly-developed porous material, and has wide application prospect.

Cyclodextrin is a naturally occurring cyclic oligosaccharide, and is produced by cyclodextrin glycosyltransferase during the enzymatic degradation of starch, the cyclodextrin usually contains 6-12D-glucopyranose units, wherein the important practical significance is that molecules containing 6, 7 and 8 glucose units are respectively called α, gamma cyclodextrin, and the metal-organic framework of the cyclodextrin enables the cyclodextrin and alkali metal ions to form a new metal-organic framework through organic coordination, and the material has good water solubility and nontoxicity compared with the traditional metal-organic framework, and is the hotspot of research at present.

The synthesis of the cyclodextrin metal organic framework mostly adopts a steam diffusion method, the preparation time of the cyclodextrin metal organic framework needs one week, and the good industrial application of the cyclodextrin metal organic framework is influenced. There are also some methods including a solvothermal method and the like, but the reaction time also requires 3 to 4 days.

Disclosure of Invention

The application provides a cyclodextrin metal organic framework material, which adopts ultrasonic assistance and combines with a surfactant, so that the reaction time is shortened, and the prepared cyclodextrin metal organic framework material has uniform and regular particle size and good geometric appearance.

The cyclodextrin metal-organic framework material is prepared by the following method:

dissolving cyclodextrin and alkali metal in water to obtain water solution;

mixing the obtained water solution with a solvent to obtain a mixed solution;

carrying out ultrasonic treatment on the mixed solution, and adding a surfactant while carrying out ultrasonic treatment to obtain a crude product;

and carrying out post-treatment on the crude product to obtain the product.

The key point of the technical scheme is the dual restriction of the surfactant and the ultrasonic treatment, and the target product with uniform and regular particle size and good geometric appearance can be obtained only by matching ultrasonic under the condition of simultaneously adding the surfactant.

Several alternatives are provided below, but not as an additional limitation to the above general solution, but merely as a further addition or preference, each alternative being combinable individually for the above general solution or among several alternatives without technical or logical contradictions.

Optionally, the cyclodextrin is α -cyclodextrin, β -cyclodextrin, gamma-cyclodextrin, hydroxypropyl- β -cyclodextrin, sulfobutyl- β -cyclodextrin, methyl- β -cyclodextrin, carboxymethyl- β -cyclodextrin or a combination of any one of the above.

Optionally, the alkali metal hydroxide is at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and francium hydroxide.

Optionally, the addition amount of cyclodextrin is 0.01mmol/m L-0.05 mmol/m L, the addition amount of alkali metal oxide is 0.1mmol/m L-0.5 mmol/m L, and the mixing volume ratio of the aqueous solution to the solvent is 5 (1-5) when the mixed solution is prepared.

Optionally, the addition amount of cyclodextrin is 0.01mmol/m L-0.05 mmol/m L, and the addition amount of alkali metal oxide is 0.1mmol/m L-0.5 mmol/m L.

Optionally, the addition amount of cyclodextrin is 0.02mmol/m L-0.03 mmol/m L, and the addition amount of alkali metal oxide is 0.2mmol/m L-0.3 mmol/m L.

Optionally, the cyclodextrin is added in an amount of 0.025mmol/m L and the alkali metal oxide is added in an amount of 0.228mmol/m L.

Optionally, when the mixed solution is prepared, the mixing volume ratio of the aqueous solution to the solvent is 5: (1-5).

Optionally, the mixing volume ratio of the aqueous solution to the solvent is 5: 3.

optionally, the solvent is methanol, ethanol, isopropanol or any combination thereof.

Optionally, the ultrasonic treatment conditions are: the frequency is 20-22 kHz, the power is 96-768W, and the effective ultrasonic time is 3-60 min.

Further, the ultrasonic treatment conditions are as follows: the frequency is 20-22 kHz, the power is 270-540W, and the effective ultrasonic time is 8-20 min.

Optionally, the ultrasonic treatment is intermittent ultrasonic treatment, and in one period of the intermittent ultrasonic treatment, the ultrasonic time is 1-3 s, and the intermittent time is 1-3 s.

Intermittent ultrasound, namely ultrasound is stopped for a certain time and then is carried out circularly. The effective sonication time refers to the sum of all sonication times.

Optionally, the ultrasonic treatment is performed in a rod-type ultrasonic mode in which an ultrasonic probe extends into the mixed liquid.

Optionally, the surfactant is polyethylene glycol, povidone, polysorbate, sorbitan monolaurate, polyoxyethylene lauryl ether, a nonylphenol polyoxyethylene ether condensate, polyoxyethylene fatty alcohol ether, a polyoxyethylene polypropylene glycol condensate, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, dodecyl dimethyl benzyl ammonium bromide or any combination thereof.

Further optionally, the surfactant is polyethylene glycol.

Optionally, the addition amount of the surfactant is 0.001mmol/m L-0.005 mmol/m L.

Optionally, the ultrasonic treatment conditions comprise that the frequency is 20-22 kHz, the power is 270-540W, the effective ultrasonic time is 8-20 min, the surfactant is polyethylene glycol, and the addition amount of the surfactant is 0.001mmol/m L-0.005 mmol/m L.

Further optionally, the ultrasonic treatment conditions comprise that the frequency is 20kHz, the power is 270W-540W, the reaction is carried out for 10min under the intermittent action, the surfactant is polyethylene glycol (8000), the addition amount of the surfactant is 0.001mmol/m L, the higher ultrasonic frequency and the higher ultrasonic power are favorable for the uniform and regular particle size of the product and the good geometric shape, and the simultaneous implementation of the surfactant and the ultrasonic treatment is one of the key factors of the invention so as to obtain the target product with the uniform and regular particle size and the good geometric shape.

Optionally, the post-processing includes: and (4) standing, and then sequentially filtering, washing and drying.

The application also provides a preparation method of the cyclodextrin metal-organic framework material, which comprises the following steps:

dissolving cyclodextrin and alkali metal in water to obtain water solution;

mixing the obtained water solution with an organic solvent to obtain a mixed solution;

carrying out ultrasonic treatment on the mixed solution, and then adding a surfactant to obtain a crude product;

and carrying out post-treatment on the crude product to obtain the product.

The additional technical features as described above for the further definition of the cyclodextrin metal-organic framework material are all adapted to the definition of the preparation method and are not described herein again.

Although a plurality of synthesis methods for preparing cyclodextrin metal organic framework compounds exist at present, a method for efficiently crystallizing a cyclodextrin metal organic framework by combining an ultrasonic method with a surfactant is not reported, and compared with the prior art, the method has at least the following advantages:

(1) the ultrasonic synthesis method shortens the reaction time, has the advantages of simple operation, mild reaction conditions, environmental friendliness, low cost, high reaction yield and the like, and is easy to realize industrial production.

(2) The cyclodextrin metal organic framework material ultrasonically synthesized according to the method has the advantages of uniformity, regularity, good geometric appearance, good thermal stability and chemical stability, and can be applied to the fields of gas adsorption, medicine carrying, optics, electric conductors, catalysis and the like.

Drawings

FIG. 1 is a powder X-ray diffraction pattern of the metal-organic framework of cyclodextrin synthesized in example 1;

fig. 2 is a scanning electron micrograph of the metal-organic framework of cyclodextrin synthesized in example 1.

Fig. 3 is a scanning electron micrograph of the cyclodextrin metal-organic framework synthesized in comparative example 3.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

Cyclodextrin (CD) is a general name of a series of cyclic oligosaccharides produced by amylose under the action of Cyclodextrin glucosyltransferase produced by bacillus, and generally contains 6-12D-glucopyranose units, wherein the more researched and important practical significance is that the molecule contains 6, 7 and 8 glucose units, which are respectively named as α -Cyclodextrin, β -Cyclodextrin and gamma-Cyclodextrin₄₈H₈₀O₄₀Molecular weight is 1297.1248, CAS registry number 17465-86-0.

Alkali metal (alkali metal) refers to all the metal elements in group ia of the periodic table, and currently, lithium (L i), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr) are the six types of hydroxides, namely lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide and the like, which are soluble and strongly basic.

The cyclodextrin and the alkali metal hydroxide may be dissolved in water by mixing the cyclodextrin, the alkali metal hydroxide and water, stirring at room temperature to sufficiently dissolve the cyclodextrin and the alkali metal hydroxide, and further filtering with a 0.45 μm aqueous filter to remove impurities in the solution.

A solvent is a liquid that can dissolve a solid, liquid or gaseous solute, which in turn becomes a solution. The solvents are classified into inorganic solvents and organic solvents. Water is the most widely used inorganic solvent, and organic solvents are organic compounds containing carbon atoms, which are liquid at room temperature and include many types of substances. Common organic solvents include alkanes, alkenes, alcohols, aldehydes, amines, esters, ethers, ketones, aromatic hydrocarbons, hydrogenated hydrocarbons, terpene hydrocarbons, halogenated hydrocarbons, heterocyclic compounds, nitrogen-containing compounds, sulfur-containing compounds, and the like. In one embodiment of the present application, the solvent is selected from methanol, ethanol, isopropanol, or a combination thereof, and further, methanol is used.

The cyclodextrin and the alkali metal hydroxide are dissolved in water, the aqueous solution is mixed with the solvent, the mixture of the aqueous solution and the solvent can be mixed firstly and then added into the ultrasonic tube, or the solvent can be added into the ultrasonic tube in advance, and then the cyclodextrin, the aqueous solution of the alkali metal and the methanol are placed in a water bath kettle to obtain clear and transparent liquid. The water bath temperature is 50-80 ℃, and the optimal temperature is 60 ℃; the water bath time is 5min to 30min, preferably 15 min.

Ultrasonic waves are sound waves with frequencies above 20kHz, which are a specific type of energy that can produce powerful shock waves to erode, activate and clean surfaces. The physical and chemical properties generated by ultrasonic cavitation can provide a new means and method for preparing materials.

The ultrasonic treatment refers to placing the mixed solution in an ultrasonic device, reacting under ultrasonic conditions, wherein the ultrasonic treatment process is carried out in the ultrasonic device, the ultrasonic device comprises but is not limited to an ultrasonic cell crusher, an ultrasonic cleaning machine and an ultrasonic generator, and in one embodiment of the application, the ultrasonic treatment is carried out in an ultrasonic JY92-IIDN type device.

The ultrasonic mode comprises a water bath ultrasonic treatment mode, a rod type ultrasonic treatment mode and the like, in a preferred embodiment of the application, rod type ultrasonic is adopted, namely an ultrasonic probe is stretched into reaction liquid, and ultrasonic equipment is started to carry out ultrasonic treatment. In a preferred embodiment, the probe is a 6mm probe (6mm specification means probe diameter), the reaction mixture is placed in an ultrasonic tube, and the probe extends about 2cm below the liquid level of the mixture in the ultrasonic tube to perform ultrasonic treatment on the mixture. Compared with water bath ultrasonic treatment, rod type ultrasonic treatment can control the ultrasonic energy density according to the output power and the volume of the solution to be subjected to ultrasonic treatment, and can perform ultrasonic operation with higher intensity, so that the product has more uniform and regular particle size and good geometric appearance.

The ultrasound mode includes continuous ultrasound or intermittent ultrasound, in a preferred embodiment, intermittent ultrasound is adopted, and continuous ultrasound treatment can affect the crystallization of the metal organic framework of cyclodextrin due to continuous work, and on the other hand, the ultrasound equipment is easy to damage, and the long-term performance and the repeated use of experiments are not facilitated.

In one embodiment, the conditions of sonication are: the frequency is 20-22 kHz, the power is 96-768W, and the effective ultrasonic time is 3-60 min. The preferred ultrasonic power is 270W to 540W, and 540W is the most preferred. The preferable effective ultrasonic time is 5min-30min, and the best is 10 min. In one period of the intermittent ultrasonic treatment, the ultrasonic time is 1-3 s, and the intermittent time is 1-3 s. In a preferred embodiment, the ultrasound time is 2s and the intermittent time is 2s in one cycle of the intermittent ultrasound treatment. The effective sonication time refers to the sum of all sonication times.

The surfactant is a substance which has fixed hydrophilic and lipophilic groups, can be directionally arranged on the surface of a solution and can obviously reduce the surface tension. One end of the surfactant is a nonpolar hydrocarbon chain (alkyl group), has extremely low affinity with water and is often called as a hydrophobic group; the other end being a polar group (e.g. -OH, -COOH, -NH)₂、—SO₃H, etc.) having a large affinity for water, so it is called hydrophilicWater-based, collectively referred to as "amphiphilic molecules" (lipophilic and hydrophilic molecules). They are classified into anionic surfactants, cationic surfactants, zwitterionic surfactants and nonionic surfactants according to the dissociation properties of polar groups. In a preferred embodiment, the surfactant is polyethylene glycol, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, dodecyl dimethyl benzyl ammonium bromide or any combination thereof.

In a more preferred embodiment of the present application, a nonionic surfactant polyethylene glycol is employed. Polyethylene glycol (PEG) is a high polymer prepared by intermolecular dehydration condensation of ethylene glycol and has a chemical formula of HOCH₂(CH₂OCH₂)_nCH₂OH, wherein n is greater than 4. The numbers following the commercial polyethylene glycol indicate its molecular weight. For example, PEG-400 means an average molecular weight of 400, and PEG products having a molecular weight of 200 and 20000 are available. In the present application, preferably, polyethylene glycol 8000(PEG8000) is used.

The surfactant is added rapidly after the start of the sonication, the amount of surfactant added is 0.001mmol/m L-0.005 mmol/m L, and in a more preferred embodiment, the amount of surfactant added is 0.001mmol/m L.

The better ultrasonic condition and the better surfactant type and addition have good synergistic effect, and the obtained product has uniform and regular particle size and good geometric appearance.

The post-treatment can be generally conventional post-treatment, and in one embodiment, comprises: the crude product is transferred from the ultrasonic tube to a beaker and the temperature of the crude product at room temperature can be from 4 ℃ to 30 ℃. The standing time can be 0.5h-24 h; standing for a certain time, centrifugally washing the precipitate for several times by using methanol, and dispersing the precipitate into the methanol after centrifugal separation; and then putting the product after centrifugal separation into a vacuum drying oven, vacuum-drying for 6-24 h at 50-90 ℃ under a vacuum condition, and cooling to room temperature to obtain the cyclodextrin metal-organic framework material. The cyclodextrin metal-organic framework material has uniform and regular particle size and good geometric appearance.

The following is illustrated by specific examples, in which the operating methods without specific conditions being noted are generally carried out according to conventional conditions, or according to conditions recommended by the manufacturer.