Preparation method of antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material

文档序号：1789619 发布日期：2021-11-05 浏览：3次中文

阅读说明：本技术 一种抑菌型偕胺肟基修饰磁性二氧化钛核壳结构吸附材料的制备方法 (Preparation method of antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material ) 是由王志宁李楠于 2021-07-20 设计创作，主要内容包括：本发明涉及一种抑菌型偕胺肟基修饰磁性二氧化钛核壳结构吸附材料的制备方法,该方法首先以Fe-(3)O-(4)、钛酸四丁酯和乙酰丙酮为原料,通过钛酸四丁酯水解反应在Fe-(3)O-(4)表面形成TiO-(2)层,得到核壳结构Fe-(3)O-(4)@TiO-(2)纳米粒子,然后在TiO-(2)表面接枝偕胺肟,得到抑菌型偕胺肟基修饰磁性二氧化钛核壳结构吸附材料,制备工艺简单,不需要复杂的硬件设备,对环境无污染,原料易得,原料为环境友好型材料,无毒无害,制作成本低,在温和条件下即可制备高性能的吸附材料,核壳结构Fe-(3)O-(4)@TiO-(2)纳米粒子制备过程中,条件温和,避免了钛酸四丁酯水解剧烈而无法在Fe-(3)O-(4)表面形成TiO-(2)层,得到核壳结构稳定,方法简单。(The invention relates to a bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing materialThe preparation method comprises the steps of firstly using Fe 3 O 4 Tetrabutyl titanate and acetylacetone are taken as raw materials, and hydrolysis reaction is carried out on the tetrabutyl titanate in Fe 3 O 4 Surface formation of TiO 2 Layer to obtain Fe with core-shell structure 3 O 4 @TiO 2 Nanoparticles, then on TiO 2 The antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material is obtained by grafting amidoxime on the surface, the preparation process is simple, complex hardware equipment is not needed, no pollution is caused to the environment, raw materials are easy to obtain, the raw materials are environment-friendly materials, and are non-toxic and harmless, the preparation cost is low, the high-performance adsorbing material can be prepared under mild conditions, and the core-shell structure Fe is a Fe adsorbing material 3 O 4 @TiO 2 In the process of preparing the nano particles, the condition is mild, and the condition that the tetrabutyl titanate is violently hydrolyzed and can not be in Fe is avoided 3 O 4 Surface formation of TiO 2 The obtained core-shell structure is stable, and the method is simple.)

1. A preparation method of a bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorption material comprises the following steps:

(1) mixing Fe₃O₄Dispersing the particles into an ethanol solution, and uniformly dispersing to obtain a solution a; adding tetrabutyl titanate and acetylacetone into absolute ethyl alcohol, uniformly mixing to obtain a solution b, dropwise adding the solution b into the solution a under the ultrasonic condition, continuing ultrasonic treatment for 30-120 minutes after dropwise adding, then carrying out reflux reaction for 80-120 minutes at 80-100 ℃, cooling to room temperature after reaction, washing with ethanol, and carrying out vacuum drying to obtain the core-shell structure Fe₃O₄@TiO₂Nanoparticles;

(2) forming a core-shell structure of Fe₃O₄@TiO₂And adding the nano particles and the polyamidoxime into deionized water, and performing ultrasonic treatment for 30-120min to obtain a sample, cleaning and vacuum drying the sample to obtain the antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material.

2. The method according to claim 1, wherein in the step (1), the solution a is prepared as follows:

firstly Fe₃O₄Adding the granules into water, performing ultrasonic treatment for 8-15min, adding ethanol, and performing ultrasonic treatment for 15-25min to obtain solution a, Fe₃O₄The mass-volume ratio of the particles to the water is as follows: (0.1-0.5): (10-30) units of g/mL, Fe₃O₄The mass-volume ratio of the particles to the water is as follows: (0.1-0.5): (200- & lt300- & gt), unit g/mL.

3. The method according to claim 1, wherein in the step (1), the volume ratio of the absolute ethyl alcohol to the tetrabutyl titanate is (5-30): 1, the volume ratio of the absolute ethyl alcohol to the acetylacetone is (3-8) to 1.

4. The method according to claim 1, wherein in the step (1), Fe₃O₄The granules are prepared by the following method:

2.6g of FeCl was taken₃·6H₂O, 4.8g of sodium acetate and 1.0g of sodium citrate in that orderAdding into 80mL of ethylene glycol, stirring at room temperature for 0.5-2 hours, transferring the mixed solution into a polytetrafluoroethylene inner container, reacting at 200 ℃ for 10 hours, cooling to room temperature after the reaction is finished, and repeatedly washing Fe with deionized water₃O₄Granulating, and drying at 50 deg.C under vacuum to obtain Fe₃O₄And (3) granules.

5. The production method according to claim 1, wherein in the step (2), Fe has a core-shell structure₃O₄@TiO₂The mass volume ratio of the nano particles to the deionized water is as follows: (0.01-0.1): 10, unit g/mL, core-shell structure Fe₃O₄@TiO₂The mass ratio of the nano particles to the polyamidoxime is (0.01-0.1): (0.001-0.1).

6. The method according to claim 1, wherein in the step (2), the polyamidoxime is prepared by:

adding hydroxylamine hydrochloride, anhydrous potassium carbonate and polyacrylonitrile into the water-alcohol mixed solution, uniformly mixing to obtain a mixed solution, reacting the mixed solution at 70-90 ℃ for 5-8 hours under the protection of nitrogen, cooling to room temperature after the reaction is finished, centrifugally cleaning with the water-alcohol mixed solution, and freeze-drying to obtain the polyamidoxime.

7. The preparation method according to claim 6, wherein the mass ratio of hydroxylamine hydrochloride to anhydrous potassium carbonate is: 1:1, wherein the mass ratio of hydroxylamine hydrochloride to polyacrylonitrile is as follows: (1-3): 1.

8. the preparation method according to claim 1, wherein the mass-to-volume ratio of the mixed solution of hydroxylamine hydrochloride and water alcohol is: (0.4-1): (80-100), the unit g/mL, the volume ratio of water to alcohol in the water-alcohol mixed solution is as follows: 1:9.

9. The application of the bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material prepared by the preparation method of claim 1 in removing or enriching hexavalent uranium in wastewater, and performing bacteriostasis under ultraviolet irradiation.

10. The application of claim 9, wherein the addition amount of the bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material is 20-120mg/25mL, the concentration of hexavalent uranium in wastewater is 3.5 μ g/L-200mg/L, and the adsorption time is 5min-33 day; the adsorption reaction temperature is 25-45 ℃, the ultraviolet irradiation time is 30min-2h, and the ultraviolet lamp power is 20W-500W.

Technical Field

The invention relates to a preparation method of a bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material, belonging to the technical field of chemistry and environment.

Background

Nuclear energy is used as clean and efficient energy, and the proportion of the nuclear energy in energy supplied to the world is increased year by year. With the explosive development of the nuclear industry, the demand for uranium has also remained steadily increasing. The availability of terrestrial uranium ore is limited and there is a critical need to find alternative uranium for sustainable development. The uranium reserves in seawater are abundant, about 45 hundred million tons, which is equivalent to one thousand times of reserves of uranium ores on land, and the uranium reserves can be economically and effectively extracted, so that the uranium reserves are important supplement and guarantee for the stable development of nuclear power industry and nuclear power. In addition, a large amount of high-concentration uranium-containing wastewater is discharged in uranium ore mining, nuclear fuel use and nuclear power station leakage. The uranium is required to be enriched and recovered from the water body urgently by comprehensively considering two aspects of energy extraction and environmental management. At present, the method for treating hexavalent uranium in water mainly comprises reduction precipitation, membrane separation, extraction, electrolytic recovery, ion exchange, adsorption and the like. Among them, the adsorption method is considered as one of the most effective treatment methods.

The biological contamination of the adsorbent severely limits the adsorption performance of the adsorbent and increases the application cost. The development of the antibacterial adsorbent can improve the performance and the service life of the adsorbent, and titanium dioxide has better antibacterial activity, but the titanium dioxide is usually powdery, is complex and time-consuming in separation operation with a water body after adsorbing hexavalent uranium and needs to be immobilized on other materials. Ferroferric oxide (Fe)₃O₄) It is commonly used as catalyst, recording material, magnetic fluid material and electronic material, etc., and is one of the most widely used soft magnetic materials. Fe₃O₄Has good magnetic responsiveness and can realize rapid separation in the presence of an external magnetic field. Mixing Fe₃O₄The combination with titanium dioxide can effectively solve the problem that the titanium dioxide is difficult to separate and recycle. Further, by constructing the core-shell structure particles, it is possible toSo as to improve the adsorption capacity of the adsorbent to hexavalent uranium. At present, Fe₃O₄The core-shell structures with titanium dioxide are usually produced by the following process, Fe₃O₄Is sequentially coated with SiO₂And TiO₂Wrapping to form core-shell Fe₃O₄@SiO₂@TiO₂Then with Fe₃O₄@SiO₂@TiO₂Removing the sandwich silicon dioxide by a concentrated alkali treatment method to obtain the core-shell Fe₃O₄@TiO₂The preparation method is complex, and the obtained core-shell structure is unstable.

The amidoxime group is considered to have strong coordination and selective adsorption capacity to uranyl. Functional groups such as amidoxime and the like can be introduced on the surface of the magnetic nano particle, so that the adsorption capacity and selectivity of the magnetic nano particle with the core-shell structure are further improved. Currently, studies on bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing materials are rarely reported at home and abroad.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of a bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material.

The invention is realized by the following technical scheme:

a preparation method of a bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorption material comprises the following steps:

(2) forming a core-shell structure of Fe₃O₄@TiO₂Adding the nano particles and the polyamidoxime into deionized water, performing ultrasonic treatment for 30-120min, cleaning the obtained sample, and performing vacuum dryingAnd drying to obtain the antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material.

According to a preferred embodiment of the invention, solution a is prepared as follows:

According to the invention, in the step (1), the volume ratio of the absolute ethyl alcohol to the tetrabutyl titanate is (5-30): 1, the volume ratio of the absolute ethyl alcohol to the acetylacetone is (3-8) to 1.

Preferably, according to the invention, in step (1), the vacuum drying temperature is between 50 and 70 ℃.

In detail, core-shell structure Fe₃O₄@TiO₂The nano particles are prepared by the following method:

0.15g of Fe was taken₃O₄Dissolving in 15mL of deionized water, performing ultrasonic treatment for 10 minutes, adding 270mL of ethanol, continuing the ultrasonic treatment for 20 minutes, adding 1-6mL of tetrabutyl titanate and 5-10mL of acetylacetone into 30mL of anhydrous ethanol, uniformly mixing, and dropwise adding Fe under the ultrasonic condition₃O₄The water alcohol solution is continuously subjected to ultrasonic treatment for 30 minutes after the dropwise addition is finished, then the reflux reaction is carried out for 90 minutes at 90 ℃, the reaction solution is cooled to room temperature after the reaction is finished, the reaction solution is repeatedly washed by ethanol, and the reaction solution is subjected to vacuum drying at 60 ℃.

Preferably according to the invention, in step (1), Fe₃O₄The granules are prepared by the following method:

2.6g of FeCl was taken₃·6H₂O, 4.8g of sodium acetate and 1.0g of sodium citrate are sequentially added into 80mL of ethylene glycol and stirred for 0.5-2 hours at room temperature, then the mixed solution is transferred into a polytetrafluoroethylene inner container and reacted for 10 hours at 200 ℃, and after the reaction is finished, the mixed solution is cooled to room temperature and then repeatedly washed by deionized water to remove Fe₃O₄GranulesAnd dried under the vacuum drying condition of 50 ℃ to obtain Fe₃O₄And (3) granules.

According to a preferred embodiment of the invention, in step (2), the core-shell structure is Fe₃O₄@TiO₂The mass volume ratio of the nano particles to the deionized water is as follows: (0.01-0.1): 10, unit g/mL, core-shell structure Fe₃O₄@TiO₂The mass ratio of the nano particles to the polyamidoxime is (0.01-0.1): (0.001-0.1).

According to the invention, in the step (2), the washing is carried out by using deionized water, and the vacuum drying temperature is 50-70 ℃.

According to a preferred embodiment of the present invention, in step (2), the polyamidoxime is prepared by the following method:

Further preferably, the mass ratio of the hydroxylamine hydrochloride to the anhydrous potassium carbonate is as follows: 1:1.

Further preferably, the mass ratio of hydroxylamine hydrochloride to polyacrylonitrile is: (1-3): 1.

further preferably, the mass volume ratio of the hydroxylamine hydrochloride to the water-alcohol mixed solution is as follows: (0.4-1): (80-100) in g/mL.

Further preferably, the volume ratio of water to alcohol in the water-alcohol mixed solution is: 1:9. The alcohol is ethanol.

An antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material is prepared by the preparation method.

The application of the prepared antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material is used for removing or enriching hexavalent uranium in wastewater, and bacteriostasis is performed under ultraviolet irradiation.

According to the preferable dosage of the antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material, the dosage is 20-120mg/25 mL.

Further preferably, the concentration of hexavalent uranium in the wastewater is 3.5 mu g/L-200mg/L, and the adsorption time is 5min-35 day; the adsorption reaction temperature is 25-45 ℃.

Further preferably, the ultraviolet irradiation time is 30min-2h, and the ultraviolet lamp power is 20W-500W.

The invention firstly uses Fe₃O₄Tetrabutyl titanate and acetylacetone are taken as raw materials, and hydrolysis reaction is carried out on the tetrabutyl titanate in Fe₃O₄Surface formation of TiO₂Layer to obtain Fe with core-shell structure₃O₄@TiO₂Nanoparticle, core-shell structure Fe₃O₄@TiO₂Adding the nano particles and the polyamidoxime into deionized water for ultrasonic treatment, and adding the mixture into TiO₂And grafting amidoxime on the surface to obtain the antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material.

The preparation method has the advantages of simple preparation process, no need of complex hardware equipment, no environmental pollution, easily obtained raw materials, low manufacturing cost, and capability of controlling the core-shell structure Fe by controlling the reaction time₃O₄@TiO₂The particle size of the nano particles.

The invention has the beneficial effects that:

1. the invention firstly uses Fe₃O₄Tetrabutyl titanate and acetylacetone are taken as raw materials, and hydrolysis reaction is carried out on the tetrabutyl titanate in Fe₃O₄Surface formation of TiO₂Layer to obtain Fe with core-shell structure₃O₄@TiO₂Nanoparticle, core-shell structure Fe₃O₄@TiO₂Adding the nano particles and the polyamidoxime into deionized water for ultrasonic treatment, and adding the mixture into TiO₂The antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material is obtained by grafting the polyamidoxime on the surface, the preparation process is simple, complex hardware equipment is not needed, no pollution is caused to the environment, raw materials are easy to obtain, the raw materials are environment-friendly materials, and the antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material is non-toxic and harmless, low in manufacturing cost and capable of preparing a high-performance adsorbing material under mild conditions.

2. Core-shell structure Fe of the invention₃O₄@TiO₂In the process of preparing nanoparticles, the stripsThe temperature is mild, and the condition that tetrabutyl titanate is violently hydrolyzed and can not be in Fe is avoided₃O₄Surface formation of TiO₂Layer to obtain Fe with core-shell structure₃O₄@TiO₂Stable structure and simple method.

3. The antibacterial amidoxime group modified magnetic titanium dioxide core-shell structure adsorbing material prepared by the invention can remove or enrich hexavalent uranium in wastewater, has an antibacterial effect, is easy to recover and recycle, and is environment-friendly, good in adsorption effect and antibacterial.

Drawings

Fig. 1 is a scanning electron microscope and a transmission electron microscope image of the adsorbing materials prepared in example 1, comparative example 1 and comparative example 2 of the present invention, wherein a is the scanning electron microscope image of comparative example 2, b is the scanning electron microscope image of comparative example 1, c is the scanning electron microscope image of example 1, c is the transmission electron microscope image of comparative example 2, d is the transmission electron microscope image of comparative example 1, and e is the transmission electron microscope image of example 1.

FIG. 2 FTIR spectra of the adsorbent materials prepared in inventive example 1, comparative example 1 and comparative example 2.

FIG. 3 shows an XPS peak spectrum of the prepared adsorbing material in example 1 of the present invention: a is Fe 2p, b is Ti 2p, and C is C1 s.

Fig. 4 shows nitrogen adsorption/desorption curves of the adsorbent materials prepared in example 1, comparative example 1 and comparative example 2 of the present invention.

FIG. 5 shows hysteresis loops of adsorbents prepared in example 1 of the present invention and in comparative example 2.

FIG. 6 shows the adsorption amounts and zeta potentials of the adsorbing materials prepared in example 1, comparative example 1 and comparative example 2 of the present invention at different pH values, where a is the adsorption amount and b is the zeta potential;

FIG. 7 is a graph showing the change with time in the adsorption amount of the adsorbent prepared in example 1 of the present invention.

FIG. 8 shows a kinetic fit curve of the adsorption material prepared in example 1 of the present invention, where a is pseudo first order kinetics and b is pseudo second order kinetics.

FIG. 9 is an adsorption isotherm of the adsorbent prepared in example 1 of the present invention.

FIG. 10 shows the cycle regeneration performance of the adsorbent prepared in example 1 of the present invention.

FIG. 11 shows the adsorption performance of the adsorbent prepared in example 1 of the present invention when metal ions and anions are interfered at equal concentrations, where a is cation interference and b is anion interference.

Fig. 12 shows the adsorption performance of the adsorption material prepared in example 1 of the present invention on different metal ions in real seawater for 33 days.

Fig. 13 shows bacteriostatic properties of the adsorbing materials prepared in example 1, comparative example 1, and comparative example 2 of the present invention.

Detailed Description

The invention will be further illustrated by the following examples in conjunction with the accompanying drawings,

the starting materials used in the examples are all conventional commercial products.

Examples 1,

A preparation method of a bacteriostatic amidoxime group modified magnetic titanium dioxide core-shell structure adsorption material comprises the following specific steps:

(1) 2.6g FeCl was weighed₃·6H₂O, 4.8g of sodium acetate and 1.0g of sodium citrate were dissolved in 80mL of ethylene glycol in this order and stirred at room temperature for one hour. Then transferring the mixed solution into a polytetrafluoroethylene inner container, screwing down the hydrothermal kettle, and reacting for 10 hours at 200 ℃. After the reaction is finished and the temperature is cooled to room temperature, the deionized water is used for repeatedly cleaning Fe₃O₄The granules are dried under vacuum drying conditions at 50 ℃ to obtain Fe₃O₄。

(2) 0.15g of Fe was weighed₃O₄Dissolved in 15mL of deionized water and sonicated for 10 minutes. 270mL of ethanol was then added thereto and sonication was continued for 20 minutes. Adding 5mL of tetrabutyl titanate and 6.67mL of acetylacetone into 30mL of absolute ethanol, uniformly mixing, and dropwise adding Fe under ultrasonic condition₃O₄The solution of (2) is added with water and alcohol, ultrasonic treatment is continued for 30 minutes after the dropwise addition is finished, and then the reflux reaction is carried out for 90 minutes at 90 ℃. After the reaction is finished, cooling to room temperature, repeatedly cleaning with ethanol, and carrying out vacuum drying at 60 ℃ to obtain Fe₃O₄@TiO₂。

(3) 0.6g of hydroxylamine hydrochloride, 0.6g of anhydrous potassium carbonate and 0.3g of polyacrylonitrile were weighed and dissolved in 90mL of a water/alcohol (volume ratio: 1: 9) mixture. The mixture was then reacted at 80 ℃ for 6 hours under nitrogen. After the reaction is finished, cooling to room temperature, carrying out centrifugal cleaning on the mixture by using a water/alcohol (volume ratio is 1: 9), and then carrying out freeze drying to obtain the PAO.

(4) 0.05g of Fe₃O₄@TiO₂And 0.025g of polyamidoxime PAO into 10mL of deionized water, carrying out ultrasonic treatment for 30 minutes, then washing a sample by using the deionized water, and carrying out vacuum drying on the sample at 60 ℃ to obtain the product.

Examples 2,