Preparation method and application of cyclodextrin porous material

Abstract

The invention relates to a preparation method and application of a cyclodextrin porous material, and the cyclodextrin porous material is a beta-cyclodextrin membrane material which is synthesized from beta-cyclodextrin and cyanuric chloride under the condition of an alkaline solution and has a dye filtering function. The preparation method comprises the following steps: dissolving beta-cyclodextrin in an alkaline solution, dissolving cyanuric chloride in tetrahydrofuran, slowly dripping a solution B close to an interface of a solution A, taking out a film after the solution interface is stable after dripping, washing the film with deionized water and an organic solvent for 3-4 times, filtering and drying to obtain pure white solid particles, and drying the pure white solid particles to obtain the beta-cyclodextrin / cyanuric chloride composite material. Obtaining the cyclodextrin porous material. The whole reaction process is carried out at room temperature, the film forming reaction can be completed without any catalyst, the method is an environment-friendly adsorption material preparation method, and the synthesized cyclodextrin porous material has the characteristics of easiness in separation, high adsorption rate, low cost, reusability and the like, and is suitable for industrial production. The material can be applied to the water purification treatment industry as a novel material, and has industrial large-scale application value.

Description

Technical Field

[0001] The invention relates to the field of adsorption materials, and in particular to a preparation method and application of a cyclodextrin porous material, which can be used for adsorbing dyes in water environments or industrial wastewater. Background Art

[0002] Industrial wastewater containing dyes and heavy metal ions discharged into rivers, seas and oceans will cause irreparable environmental pollution and ecological damage, which in turn affects human health and survival. Therefore, it is of great significance to study environmental protection and wastewater treatment. How to scientifically and efficiently treat wastewater has become a key research direction in the field of environmental protection in recent years.

[0003] According to research reports, the main methods for removing dye wastewater include physical methods, membrane separation, biological methods and chemical methods. The adsorption method is widely used in dye pollution treatment due to its low cost and easy operation. The adsorption method is not only convenient to operate, but also can achieve very efficient treatment effects. It has a wide range of applications and plays a huge role in practical applications. In order to achieve effective dye removal, it is very important to choose a suitable adsorbent for dye removal. Commonly used adsorbents include activated carbon, fly ash and adsorption resin. (Chang Guohua, Dang Yaxin, Yue Bin, et al. Study on the adsorption and regeneration of methyl green by artificial zeolite / activated carbon [J]. Environmental Science and Technology, 2017, 40(S1):71.) (Wei Ruili, Li Rongrong, Mu Yingxiu, et al. Study on the adsorption of methyl orange by graphene oxide modified fly ash [J]. Contemporary Chemical Industry, 2021, 50(12):2830.) (Zhang Hao, Li Fan, Chang Na, et al. Preparation of carboxylic acid grafted starch adsorption resin and its dye removal performance [J]. Journal of Materials Research, 2021, 35(6):419.). However, these adsorbents have the disadvantages of low adsorption capacity, high production cost and difficult separation and recovery. Therefore, the preparation of a new type of green, efficient, low-cost, easy to separate and high adsorption rate material has broad application prospects and value.

[0004] β-cyclodextrin has the advantages of low price, safety, and no pollution to the environment. It can be used in environmental pollution control. This type of polysaccharide has a cross-sectional trapezoidal columnar structure. Due to its unique hydrophilic surface and hydrophobic cavity, it has a good adsorption and encapsulation effect on some pollutants and small molecules. Appropriate modification of the β-cyclodextrin matrix can enhance the physical and chemical properties, and the application effect of the modified β-cyclodextrin material is more significant. It has large-scale industrial application value in dye adsorption. Summary of the invention

[0005] The object of the present invention is to provide an adsorption material which can efficiently adsorb aqueous solution or difficult-to-remove dyes in the chemical industry.

[0006] The cyclodextrin membrane porous material described in the invention comprises the following steps: dissolving β-cyclodextrin in an alkaline solution (as solution A), dissolving cyanuric chloride in tetrahydrofuran (as solution B), slowly dripping solution B close to the interface of solution A, and after the dripping is completed, after the film is formed and stabilized at the solution interface, taking out the film and washing it with deionized water and an organic solvent for 3-4 times, filtering and drying to obtain pure white solid particles, which are the cyclodextrin porous material.

[0007] Furthermore, the alkaline solution in the step is NaOH or KOH solution; the molar ratio of cyclodextrin to cyanuric chloride is 1:1 to 1:7; and the solvent of cyanuric chloride is one of ethanol, methanol, acetonitrile, THF, DMF, DMSO, dichloromethane and chloroform.

[0008] Furthermore, the concentration of the cyanuric chloride solution in the step is higher than 10%.

[0009] Furthermore, in the steps, the membrane is rinsed with deionized water until it becomes neutral, and then vacuum dried to obtain a thin film.

[0010] The β-cyclodextrin membrane material of the present invention uses β-cyclodextrin and cyanuric chloride as raw materials. Cyanuric chloride, with its unique triangular structure, can serve as an excellent cross-linking center to connect multiple hydroxyl groups on β-cyclodextrin, tightly combine β-cyclodextrin molecules together, form a more stable woven network, and effectively improve the dye retention rate.

[0011] The invention can quickly and efficiently remove the dyes methylene blue, neutral red, rhodamine B, auramine, brilliant green and crystal violet.

[0012] Compared with the prior art, the present invention has the following advantages: the reaction conditions of the present invention are relatively mild, the reaction can be carried out at room temperature without a catalyst, the operation is simple, the cost is low, the adsorption rate is high, and the adsorption speed is short. It is an environmentally friendly method for preparing an adsorption material. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the Fourier transform infrared spectrum of cyclodextrin porous material.

[0014] Figure 2 This is a scanning electron microscope image of cyclodextrin porous material.

[0015] Figure 3 This is a transmission electron microscopy image of cyclodextrin porous material.

[0016] Figure 4 .This is the adsorption experiment diagram of cyclodextrin porous material.

[0017] The present invention will be analyzed in more detail below in conjunction with the accompanying drawings and embodiments. Example 1

[0018] Dissolve β-cyclodextrin (22.68g, 0.5mol) in a 0.1-0.7mol / L NaOH aqueous solution (as solution A). After β-cyclodextrin is completely dissolved, take cyanuric chloride (3.68g, 2.5mol) and dissolve it in 100ml ethanol solution (as solution B). Slowly drip solution B close to the interface of solution A until the dripping is complete. After the film is formed and stabilized on the solution interface, take out the film and wash it with deionized water and organic solvent for 3-4 times, filter and dry to obtain pure white solid particles with a yield of 98%. The reaction formula is shown in Formula 1:

[0019] Example 2 Use deionized water to prepare dye solutions (methylene blue, neutral red, rhodamine B, auramine, brilliant green, crystal violet) with a concentration of 5×10-5mol / L. Prepare 6 conical flasks of the same capacity, add 200ml of 5×10-5mol / L aqueous solutions of methylene blue, neutral red, rhodamine B, auramine, brilliant green, and crystal violet respectively, take 6 equal amounts of cyclodextrin porous materials (0.2g) and add them to the 6 dye solution bottles, wait for 2 hours, and measure the concentration of the dye solution. As shown in Table 1, the adsorption amount of cyclodextrin porous materials in different organic dye solutions is shown, and the adsorption effect of rhodamine B is the best.

[0020] Table 1. Adsorption of cyclodextrin porous materials in different organic dye solutions

Claims

1. A cyclodextrin porous material, the structural formula of which is:

2. A method for preparing and using a cyclodextrin porous material according to claim 1, characterized in that: The following steps are involved: a. Take β-cyclodextrin and dissolve it in an alkaline solution of a certain concentration as solution A. b. Dissolve cyanuric chloride in an organic solvent as solution B. c. Slowly drip solution B close to the interface of solution A until the addition is complete. d. After the film is formed and stabilized at the solution interface, take out the film and wash it 3-4 times with deionized water and an organic solvent, filter and dry it to obtain pure white solid particles.

3. The preparation method and application of a cyclodextrin porous material according to claim 1, characterized in that: The alkaline solution in step a can be an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide.

4. The preparation method and application of a cyclodextrin porous material according to claim 1, characterized in that: The molar ratio of β-cyclodextrin to alkaline solution in step a is β-cyclodextrin:NaOH=1:5 or β-cyclodextrin:KOH=1:

6.

5. The preparation method and application of a cyclodextrin porous material according to claim 1, characterized in that: The organic solvent in step (2) is any one of anhydrous ethanol, anhydrous methanol, dichloromethane, acetonitrile, tetrahydrofuran and dimethyl sulfoxide, preferably anhydrous ethanol.

6. The preparation method and application of a cyclodextrin porous material according to claim 1, characterized in that: The molar ratio of β-cyclodextrin to cyanuric chloride is 1:1 to 1:10, and the preferred molar ratio is 1:

5.

7. The preparation method and application of a cyclodextrin porous material according to claim 1, characterized in that: Features The concentration of the cyanuric chloride solution in step b is greater than or equal to 10%.

8. The preparation method and application of a cyclodextrin porous material according to claim 1, characterized in that: Features In step c, the solution should be added dropwise close to the solution interface, and the dropper should not be inserted into the solution for addition.

9. The preparation method and application of a cyclodextrin porous material according to claim 1, characterized in that In step d, the organic solvent used for washing is any one of ethanol, methanol and dichloromethane, preferably ethanol.

10. The preparation method and application of a cyclodextrin porous material according to claim 9, characterized in that: The dyes selected in the application are methylene blue, neutral red, rhodamine B, auramine, brilliant green, and crystal violet.

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