Preparation method of plant polyphenol chelate type decontamination agent

Abstract

The application discloses a preparation method of a plant polyphenol chelate type decontamination agent, which comprises the following steps: adding tannin, anhydrous aluminum chloride and oleoyl chloride into a reactor, sufficiently stirring the mixture under a nitrogen atmosphere and at room temperature, grafting a hydrophobic carbon chain on the tannin through a Friedel-Crafts reaction, adding a NaOH solution into the reactor, sufficiently stirring and uniformly mixing, standing and separating, reserving the water solution part, and then freezing and drying the water solution to obtain the plant polyphenol chelate type decontamination agent. The hydrophobic carbon chain is grafted on the aromatic ring system in the tannin structure based on the Friedel-Crafts reaction, the plant polyphenol chelate type decontamination agent can be endowed with amphipathic properties in the case of maximizing the metal chelating capacity, the hydroxyl groups in the tannin molecules are protected, the liposolubility of the tannin is increased, and the biological activity is retained, and the obtained plant polyphenol chelate type decontamination agent has the characteristics of green environmental protection, high safety, easy biodegradation, environmental friendliness and the like.

Description

Technical Field

[0001] This invention belongs to the field of compound preparation technology, and more specifically, this invention relates to a method for preparing a plant polyphenol chelating disinfectant. Background Technology

[0002] Nuclear energy is increasingly widely used in military and national economic sectors, and radioactive materials are widely used in military, medical, scientific research, and industrial and agricultural production. The probability of radionuclide leaks, nuclear reactor accidents, nuclear weapon explosions, and nuclear terrorist attacks is increasing, and radioactive contamination accidents occur frequently. Leaks and releases of radioactive materials cause radioactive contamination of personnel and the surrounding environment. If not promptly removed, this can cause radiation-induced skin damage. Radionuclides may enter the body through wounds, esophagus, respiratory tract, and pores, causing internal contamination and internal radiation damage; they may also cause the spread of radioactive materials, resulting in environmental pollution and harm to other personnel. Therefore, the decontamination of radioactive materials has significant theoretical and practical importance, and rapid and effective decontamination of the body surface from radioactive nuclides is crucial for the prevention and treatment of radiation sickness.

[0003] The most effective method for removing radioactive contamination from the body surface is rapid and efficient decontamination using decontamination agents. Decontamination agents are chemical substances used to remove toxic agents, radioactive materials, and biological warfare agents from the surfaces of personnel, equipment, ground, and buildings. They include disinfectants, decontaminants, and solvents. During decontamination, disinfectants or decontaminants are usually dissolved in a suitable solvent to prepare a decontamination solution. Some solvents that can dissolve toxic agents or oily contaminants can also be used directly for decontamination. However, traditional decontamination agents still have problems such as strong corrosiveness, high pollution, and incomplete removal. Therefore, it is necessary to develop a new type of decontamination agent with advantages such as non-toxicity, strong compatibility, and environmental friendliness.

[0004] Plant tannins are common polyphenolic compounds that can be used to treat animal hides, transforming them into leather with good elasticity and toughness; hence, they are also known as tannins. Plant tannins are widely found in the leaves, fruits, and seed coats of plants, second only to lignin, cellulose, and hemicellulose in abundance. Tannins can be classified in many ways; based on differences in chemical structure, they can be divided into two main categories: hydrolyzable tannins and condensed tannins. Myrica rubra tannin belongs to the condensed tannin category. The characteristic active group of myrica rubra tannin is the ortho-phenolic hydroxyl group on its benzene ring, thus giving it strong phenolic properties. Due to its unique structure, it possesses various chemical properties, reacting with compounds such as alkaloids, polysaccharides, proteins, and metal ions. It can also scavenge free radicals, inhibit bacterial growth, and act as an antioxidant. Therefore, it is often used as a metal adsorbent, a biofunctional material, a food coloring agent, a wastewater treatment agent, an antioxidant, and a leather tanning agent.

[0005] As a type of plant tannin, bayberry tannin possesses abundant hydroxyl groups. Because these active groups can selectively bind to uranium, they are often used to treat radioactive uranium contamination. However, although tannins exhibit numerous advantages in radioactive uranium contamination treatment, their water-soluble nature prevents direct application; modification is usually required to maximize their effectiveness. Therefore, it is necessary to design low-cost, high-efficiency nuclide removal materials based on the tannin's structure for efficient uranium treatment. Tannins are highly water-soluble and poorly lipid-soluble. Their molecules contain active hydroxyl groups. Introducing hydrophobic groups into the tannin molecule structure and adjusting the number of hydrophilic and lipophilic groups can increase the lipid solubility of tannins while improving their surface activity and preserving their biological activity.

[0006] Traditional tannin lipid-soluble modification involves grafting hydrophobic groups onto hydroxyl groups to increase their surface activity. However, the metal complexation of the modified tannin-based surfactant is reduced. Therefore, a novel method is needed that can both increase the hydrophobicity of tannins and protect the hydroxyl groups in the molecule. Summary of the Invention

[0007] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0008] To achieve these objectives and other advantages of the present invention, a method for preparing a plant polyphenol chelating disinfectant is provided, comprising the following steps:

[0009] Step 1: Add tannin, anhydrous aluminum trichloride and oleoyl chloride to the reactor, and stir the mixture thoroughly under nitrogen atmosphere and at room temperature. Graft hydrophobic carbon chains onto the tannin through Friedel-Crafts reaction.

[0010] Step 2: Add NaOH solution to the reactor from Step 1, stir thoroughly to mix, let stand for layering and centrifuge, retain the aqueous solution portion, and then freeze-dry the aqueous solution to obtain the plant polyphenol chelated disinfectant.

[0011] Preferably, in step one, the tannin is bayberry tannin.

[0012] Preferably, in step one, the mass-to-volume ratio of tannin, anhydrous aluminum trichloride, and oleoyl chloride is 1.7g:2~3g:10~50mL.

[0013] Preferably, in step one, hydrophobic carbon chains are grafted onto tannins via a Friedel-Crafts reaction. The specific steps are as follows: the reactor is placed in a water bath and stirred for reaction. The mixture is first heated and stirred at 40-50°C for 4-6 hours, then heated to 70-90°C and maintained for 18-20 hours, and then cooled to room temperature.

[0014] Preferably, in step two, the volume-to-mass ratio of NaOH solution to tannin in step one is 150-250 mL: 1.7 g, and the concentration is 0.05-0.2 mol / L.

[0015] Preferably, in step two, after thorough stirring and mixing, standing, and centrifugation, the aqueous solution portion is retained. The specific steps are as follows: after thorough stirring and mixing in the reactor, the product is dissolved in water, and then centrifuged using a high-speed refrigerated centrifuge to remove unreacted oleyl chloride and aluminum trichloride, retaining the aqueous solution portion.

[0016] Preferably, the volume-to-mass ratio of water to tannin in step one is 150-250 mL: 1.7 g, and the centrifugation is performed at 7000-9000 rpm for 8-12 min.

[0017] Preferably, in step two, the aqueous solution is freeze-dried by placing the obtained aqueous solution in a freeze dryer for 2 to 3 days.

[0018] Preferably, the plant polyphenol chelate decontaminant prepared by the above preparation method is used in the decontamination of radioactive materials.

[0019] This invention offers at least the following advantages: It effectively addresses the problems of low metal complexation after modification in traditional tannin-modified surfactant methods, particularly in the utilization of tannin biomass resources. Based on Friedel-Crafts reaction, this invention grafts hydrophobic carbon chains onto the aromatic ring system of tannin, maximizing its metal chelating ability while imparting amphiphilic properties. This protects the hydroxyl groups in the tannin molecule, increasing its lipid solubility while preserving its biological activity. Utilizing tannin, a renewable natural compound, this invention produces a plant polyphenol chelating decontamination agent exhibiting excellent surface properties, high safety, and environmental friendliness. Through surface-active modification, the application range of plant tannins as biomass materials is broadened. In the widespread application of radioactive materials in military, medical, scientific research, and industrial and agricultural production, this invention fully utilizes the metal chelating and biodegradable characteristics of plant tannins as biomolecules, exploring novel modification methods based on their structure, providing insights for preparing novel decontamination agents, offering application guidance for biomass materials, and exploring their practical value in nuclear emergency response.

[0020] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the synthetic route for preparing the plant polyphenol chelating disinfectant of the present invention;

[0022] Figure 2 Fourier transform infrared spectrum of the plant polyphenol chelating disinfectant prepared in Example 1;

[0023] Figure 3 A comparison of the foaming properties and foaming stability of tannin and the plant polyphenol chelate-type detergent prepared in Example 1 at different pH values ​​(4-12);

[0024] Figure 4 Surface tension diagrams of the plant polyphenol chelate-type detergent prepared in Example 1 at different concentrations;

[0025] Figure 5 Comparison of emulsifying activity indices of tannin, sodium dodecyl sulfate, and the plant polyphenol chelate-type detergents prepared in Examples 1-4;

[0026] Figure 6 Comparison of emulsification stability indices of tannin, sodium dodecyl sulfate, and the plant polyphenol chelate-type detergents prepared in Examples 1-4;

[0027] Figure 7 The graph shows a comparison of the uranium removal rate and removal capacity of the plant polyphenol chelating disinfectant prepared in Examples 1-4 with that of water. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0029] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0030] Example 1

[0031] A method for preparing a plant polyphenol chelating disinfectant includes the following steps:

[0032] Step 1: Add 1.7g of bayberry tannin, 2.67g of anhydrous aluminum trichloride and 20mL of oleoyl chloride to a round-bottom flask and stir the mixture thoroughly under a nitrogen atmosphere at room temperature. Place the round-bottom flask in a water bath and stir the reaction. First, heat and stir at 45℃ for 5 hours, then raise the temperature to 80℃ and maintain it for 19 hours, and then cool it down to room temperature.

[0033] Step 2: Add 200 mL of 0.1 mol / L NaOH solution to the round-bottom flask from Step 1, stir thoroughly to dissolve the product in 200 mL of water, and then centrifuge at 8000 rpm for 10 min using a high-speed refrigerated centrifuge to remove unreacted oleyl chloride and aluminum trichloride, retaining the aqueous solution portion; then place the obtained aqueous solution in a freeze dryer for 2-3 days to obtain a plant polyphenol chelating disinfectant, denoted as BTCD-20.

[0034] The synthetic route for the preparation of the plant polyphenol chelate-type detergent in Example 1 was plotted, as follows: Figure 1 As shown.

[0035] Using bayberry tannin (BT) as a control, Fourier transform infrared spectroscopy analysis was performed on the plant polyphenol chelate disinfectant (BTCD) prepared in Example 1. The sample and potassium bromide were weighed at a mass ratio of 1:10 and ground under an infrared lamp. The mixture was then compressed into tablets using a tablet press, and the resulting tablets were prepared at 4000-400 cm⁻¹. -1 Fourier transform infrared spectroscopy (FT-IR, PerkinElmer, USA) was performed to obtain the infrared spectral data of BTCD, and the results are as follows. Figure 2 As shown in the figure. It can be seen that the prepared BTCD exhibits a methylene stretching vibration peak (2923 cm⁻¹). -1 2852 m -1 The tannin content is significantly higher than that of bayberry because the alkyl chain of oleic acid is grafted onto the tannin. This demonstrates that the hydrophobic carbon chain was successfully grafted onto the tannin group via the Friedel-Crafts reaction.

[0036] 0.1 g of BT and the plant polyphenol chelate disinfectant (BTCD) prepared in Example 1 were added to 100 mL of deionized water to prepare solutions. The pH of the BTCD solutions was adjusted to different values ​​using 0.1 M HCl solution and / or NaOH solution. 20 mL (V0) of the solution was added to a 250 mL beaker and homogenized thoroughly at 10000 rpm for 1 minute. The liquid and foam were then quickly poured into test tubes and placed horizontally. The foam volume (V1) was recorded immediately. The foaming power was calculated based on the ratio of V1 to V0. After standing at room temperature for 30 minutes, the foam volume (V0) was recorded again. t According to V t The ratio of V0 to the foam stability is used to calculate foam stability. Each experimental group is tested three times, and the mean and standard deviation are calculated. The results are as follows: Figure 3 As shown in the figure, BT represents the bayberry tannin control group, and BTCD-pH4, BTCD-pH6, BTCD-pH8, BTCD-pH10 and BTCD-pH12 represent the foaming properties of the plant polyphenol chelate detergent prepared in Example 1 under the conditions of pH=4, 6, 8, 10 and 12, respectively.

[0037] Generally speaking, the foaming property of a surfactant is closely related to its ability to reduce the surface tension of water. The stronger the surfactant's ability to reduce the surface tension of water, the greater its foaming property, and vice versa. Defoaming occurs because the gas-liquid interface has a large boundary and strong thermodynamic instability, leading to narrowing of the liquid film and diffusion of gas in the bubbles, thus causing the bubbles to defoam. BTCD is amphiphilic, with its molecular structure containing hydrophilic hydroxyl groups and hydrophobic alkyl chains. Figure 3 As can be seen, BTCD exhibits significantly enhanced foaming properties compared to BT, indicating that this synthesis method enhances the hydrophobicity of BT. Furthermore, the foaming properties of BTCD increase with increasing pH, reaching their peak at pH 12. The stability of the foam produced by BTCD is positively correlated with its foaming performance, significantly higher than that of BT.

[0038] Different concentrations of BTCD solutions were prepared using the plant polyphenol chelating decontaminant prepared in Example 1. The surface tension of the materials at different concentrations was measured using an OCAH200 contact angle meter at 25°C. Figure 4 The surface tension and critical micelle concentration of BTCD were obtained, and the results are shown in Table 1.

[0039] Table 1

[0040] Material Surface tension (mN / m) Critical micelle concentration (g / L) BTCD 25.822 0.15

[0041] Example 2

[0042] A method for preparing a plant polyphenol chelating disinfectant includes the following steps:

[0043] Step 1: Add 1.7g of bayberry tannin, 2.67g of anhydrous aluminum trichloride and 10mL of oleoyl chloride to a round-bottom flask and stir the mixture thoroughly under a nitrogen atmosphere at room temperature. Place the round-bottom flask in a water bath and stir the reaction. First, heat and stir at 45℃ for 5 hours, then raise the temperature to 80℃ and maintain it for 19 hours, and then cool it down to room temperature.

[0044] Step 2: Add 200 mL of 0.1 mol / L NaOH solution to the round-bottom flask from Step 1, stir thoroughly to dissolve the product in 200 mL of water, and then centrifuge at 8000 rpm for 10 min using a high-speed refrigerated centrifuge to remove unreacted oleyl chloride and aluminum trichloride, retaining the aqueous solution portion; then place the obtained aqueous solution in a freeze dryer for 2-3 days to obtain a plant polyphenol chelating disinfectant, denoted as BTCD-10.

[0045] Example 3

[0046] In this embodiment, the amount of oleoyl chloride added in step two was changed to 30 mL, and the rest of the operation was the same as in Example 2, resulting in a plant polyphenol chelated detergent, denoted as BTCD-30.

[0047] Example 4

[0048] In this embodiment, the amount of oleoyl chloride added in step two was changed to 40 mL, and the rest of the operation was the same as in Example 2, resulting in a plant polyphenol chelated detergent, denoted as BTCD-40.

[0049] Emulsifying activity and emulsifying stability experiments: The plant polyphenol chelating detergents prepared in Examples 1-4 were dissolved in water, with myricetin and sodium dodecyl sulfate (SDS) as controls, and the final concentrations of the solutions obtained were 1 mg / mL and 2 mg / mL, respectively. This solution was then mixed with medium-chain triglycerides at a ratio of 1:3 (v / v) and homogenized at 10000×g for 1 minute to obtain an emulsion. At 0 and 10 minutes after homogenization, equal portions (50 μL) of the emulsion were drawn from the bottom of the container and mixed with 5 mL of 0.1% SDS solution. The absorbance of the diluted solution was measured at 500 nm using a spectrophotometer, and the emulsifying activity index (EAI) and emulsifying stability index (ESI) were obtained according to the following formulas:

[0050] EAI (m² / g) = (2×T×A0×N) / (φ×L×C×10000)

[0051] ESI (min) = (A0) / (A0-A 10 )×t

[0052] In the formula, T is 2.303, A0 is the absorbance at 0 minutes, N is the dilution factor (100), φ is the oil ratio (0.75), L is the cuvette path length (1 cm), C is the sample concentration (g / mL), and A 10 The absorbance is measured over 10 minutes, and t is the sampling interval (10 minutes).

[0053] The emulsifying ability of plant polyphenol chelated detergents was evaluated using EAI and ESI. Higher EAI and ESI values ​​indicate stronger emulsifying ability. Figure 5 Comparison of emulsifying activity indices of tannin, sodium dodecyl sulfate, and the plant polyphenol chelate-type detergents prepared in Examples 1-4; Figure 6 The chart compares the emulsification stability indices of tannin, sodium dodecyl sulfate, and the plant polyphenol chelate-type detergents prepared in Examples 1-4. It can be seen that BTCD-20 exhibits significantly improved emulsification activity and stability compared to BT, and its emulsification activity is close to that of SDS, demonstrating potential application value.

[0054] Uranium removal experiment: 0.1g of cotton cloth was soaked in a 20mg / L uranium solution for 30 minutes, and then dried in an oven. The concentration of uranium remaining in the soaking solution was determined by ICP (inductively coupled plasma) to obtain the uranium content (m1) on the cotton cloth. Then, the cotton cloth was stirred with a 30mg / L BTCD solution at a speed of 120r / min for 30 minutes, the cloth was removed and dried, and the uranium content (m2) in the BTCD solution was determined. The calculation formula is as follows:

[0055]

[0056] Using water as a control group: 0.1g of cotton cloth was soaked in 20mg / L uranium solution for 30 minutes, and then placed in an oven to dry; the concentration of uranium remaining in the soaking solution was determined by ICP (inductively coupled plasma) to obtain the uranium content (m1) on the cotton cloth; then the cotton cloth was stirred with water at a speed of 120r / min for 30 minutes, the cotton cloth was taken out and dried, and the uranium content (m2) in the water was determined.

[0057] Figure 7 The graphs show a comparison of the uranium removal rates and capacities of the plant polyphenol chelating decontaminants prepared in Examples 1-4 and water. It can be seen that BTSD has a stronger uranium removal capacity than water, with BTSD-20 exhibiting the highest uranium removal rate, exceeding 70%.

[0058] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing a plant polyphenol chelate type decontaminant, characterized by, Includes the following steps: Step 1: Add tannin, anhydrous aluminum trichloride, and oleoyl chloride to a reactor. Stir the mixture thoroughly under a nitrogen atmosphere at room temperature. Place the reactor in a water bath and stir. First, heat and stir at 40-50°C for 4-6 hours, then raise the temperature to 70-90°C and maintain it for 18-20 hours. Then cool to room temperature. Graft hydrophobic carbon chains onto the tannin via a Friedel-Crafts reaction. The mass-to-volume ratio of tannin, anhydrous aluminum trichloride, and oleoyl chloride is 1.7 g: 2.67-3 g: 10-50 mL. The tannin is myricetin. Step 2: Add NaOH solution to the reactor from Step 1, stir thoroughly to mix, let stand for layering and centrifuge, retain the aqueous solution portion, and then freeze-dry the aqueous solution to obtain the plant polyphenol chelated disinfectant.

2. The preparation method of the plant polyphenol chelate-type detergent as described in claim 1, characterized in that, In step two, the volume-to-mass ratio of NaOH solution to tannin in step one is 150-250 mL: 1.7 g, and the concentration is 0.05-0.2 mol / L.

3. The preparation method of the plant polyphenol chelate-type detergent as described in claim 1, characterized in that, In step two, after thorough stirring and mixing, standing and centrifuging to retain the aqueous solution portion, the specific steps are as follows: after thorough stirring and mixing in the reactor, the product is dissolved in water, and then centrifuged using a high-speed refrigerated centrifuge to remove unreacted oleyl chloride and aluminum trichloride, retaining the aqueous solution portion.

4. The preparation method of the plant polyphenol chelating disinfectant as described in claim 3, characterized in that, The volume-to-mass ratio of water to tannin in step one is 150-250 mL: 1.7 g, and centrifugation is performed at 7000-9000 rpm for 8-12 min.

5. The preparation method of a plant polyphenol chelating disinfectant as described in claim 1, characterized in that, In step two, the aqueous solution is freeze-dried by placing the resulting aqueous solution in a freeze dryer for 2 to 3 days.

6. The application of a plant polyphenol chelating decontaminant prepared by the preparation method according to any one of claims 1-5 in the decontamination of radioactive materials.

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