Preparation method and application of ZIF-coated PEGDA interface floating microspheres

Abstract

The invention belongs to the technical field of biomimetic enzyme immobilization, and particularly discloses a preparation method and application of ZIF-coated PEGDA interface floating microspheres, and the preparation method comprises the following steps: preparation of ZIF biomimetic lipase, preparation of PEGDA, and preparation of ZIF-coated PEGDA interface floating microspheres. The ZIF coated PEGDA interface floating microspheres prepared by the invention can efficiently degrade oil pollution in water environments such as rivers, lakes and seas under the conditions of no stirring and no emulsification, so that all biomimetic enzymes are positioned on an oil-water interface to participate in reaction, meanwhile, the microspheres have the characteristic of tolerance to extreme conditions such as high temperature, strong acid, strong alkali and high salt, and in addition, the microspheres can be repeatedly used and stably stored for a long time; the invention provides a new thought and method for developing a novel mimic enzyme and improving the interface reaction efficiency; the prepared ZIF-coated PEGDA interface floating microsphere can be flexibly set into a specific shape according to application requirements in the 3D printing process, and a new strategy is provided for enhancing the interface reaction of nano enzyme and biological enzyme.

Description

Technical Field

[0001] The present invention belongs to the technical field of enzyme immobilization, and particularly relates to a preparation method and application of ZIF@PEGDA interfacial floating microspheres. Background Art

[0002] Developing efficient, environmentally friendly and low-cost methods for treating oil pollution in water bodies is an important environmental and commercial need. At present, physical methods such as incineration, filtration, adsorption, and chemical treatments such as flocculation, extraction and salting out are commonly used in the treatment of oil pollution in water bodies, but there are problems such as high treatment costs and secondary pollution.

[0003] Biodegradation of oil pollution is an efficient, economical and eco-friendly method, mainly using microorganisms producing lipase and lipase preparations, which are widely applied to the treatment of oil pollution in water bodies. Lipase widely exists in animals, plants and microorganisms, acts on the oil-water interface between hydrophobic lipid substrates and hydrophilic media, and can catalyze the hydrolysis of triglyceride molecules into easily degradable products such as fatty acids and glycerol. However, lipase is sensitive to water body environmental conditions such as temperature, pH value and high salt, is unstable and easily inactivated; at the same time, lipase is dispersed in water bodies and is not easy to be recovered and reused, which limits its wide application in the degradation of oil pollution in water bodies. Therefore, methods such as rationally designing to improve the thermal stability and activity of lipase, chemically modifying methods to change the surface properties of lipase, and immobilizing lipase using magnetic beads, metal-organic framework material MOF, gels, etc. can effectively improve the oil pollution degradation efficiency of lipase. However, as a biological protein, lipase still has restrictive problems such as intolerance to extreme environments, poor stability and easy inactivation, and detachment from the immobilization material.

[0004] Artificial enzymes can purposefully simulate the active sites and catalytic characteristics of biological enzymes and have catalytic functions similar to biological enzymes. At the same time, due to the excellent properties of artificial enzymes such as high stability, acid and alkali resistance, they can still maintain high activity for a long time in harsh environments, and can effectively solve the limitations of biological enzymes such as instability and easy inactivation. Among them, as a metal-organic framework crystal material, metal ions in ZIF are coordinated with organic substances, which can efficiently simulate the active sites of metal biological enzymes for biomimetic molecular catalysis. Among them, porous molecular sieve ZIF synthesized with zinc as the active center and imidazole as the ligand can effectively simulate the active centers of OPH enzyme and carbonic anhydrase, and can activate water molecules to generate ·OH and ·H free radicals for substrate hydrolysis through the polarization of Zn by imidazole. At present, there are few research reports on the hydrolysis of oils and fats by ZIF. Using the catalytic characteristics of ZIF-90 to replace lipase for oil and fat degradation can effectively solve the problem of lipase instability and easy inactivation. 2+ of the active center, and can generate ·OH and ·H free radicals by activating water molecules through the polarization of Zn by imidazole 2+ for substrate hydrolysis. At present, there are few research reports on the hydrolysis of oils and fats by ZIF. Using the catalytic characteristics of ZIF-90 to replace lipase for oil and fat degradation can effectively solve the problem of lipase instability and easy inactivation.

[0005] The oil degradation reaction mainly occurs at the oil-water interface. Only at the oil-water interface can lipase contact the substrate and open the α-helix of the substrate pocket to activate the degradation of oil. However, the characteristics of the fat degradation mimetic enzyme ZIF-90, such as its high density and easy sedimentation, result in ZIF being unable to effectively locate at the oil-water interface for catalytic reactions, severely reducing the degradation efficiency. At the same time, the difficulties in recovery and reusability also hinder their industrial applications. Therefore, in this paper, based on the principle that ZIF can activate water molecules to generate ·OH and ·H free radicals for oil hydrolysis, ZIF-90 with high porosity, high specific surface area, and high stability is constructed by ICA and zinc acetate to replace natural lipase for oil pollution degradation in the water environment. In addition, it is difficult to accelerate oil degradation in the natural water environment through artificial stirring and emulsification. Meanwhile, the degradation reaction mainly occurs at the oil-water interface. It is best to enable all ZIF-90 or bioenzymes to be located at the oil-water interface for reaction. Therefore, by cleverly adding low-density micron-sized hollow glass spheres to change the density of PEGDA, the enzyme is 3D printed and embedded in the floating microspheres, and all the enzymes in the microspheres can be located at the oil-water interface to participate in the hydrolysis reaction. This study provides the possibility for the synthesis of bionic mimetic enzymes with stable catalytic functions to replace bioenzymes for industrial-scale applications, and broadens feasible and novel ideas and strategies for accelerating interfacial reactions. Summary of the Invention

[0006] The object of the present invention is to overcome the defects of incomplete interfacial reaction, difficult recovery, difficult storage, and easy inactivation under harsh conditions existing in the prior art, and to provide a preparation method and application of ZIF@PEGDA interfacial floating microspheres.

[0007] To achieve the above object, one of the technical solutions of the present invention is: a preparation method of ZIF@PEGDA interfacial floating microspheres, comprising the following steps:

[0008] (1) Preparation of ZIF mimetic enzyme: Add the dimethylformamide solution of zinc acetate dihydrate to the dimethylformamide solution of imidazole-2-carboxaldehyde (2-ICA) for reaction, add dimethylformamide to further stabilize the spheres, then centrifuge to collect the precipitate, and then wash, centrifuge, and clean the precipitate, followed by vacuum drying and activation, and finally grind to obtain ZIF powder;

[0009] (2) Preparation of PEGDA: Dissolve PEG6000 in dichloromethane, then add an acid-binding agent, and slowly dropwise add the dichloromethane solution of acryloyl chloride for reaction. After the reaction, wash off the excess acryloyl chloride and inorganic salts, separate the liquid, dry the organic phase with anhydrous magnesium sulfate, and then rotary evaporate and concentrate. The concentrated solution is added to n-hexane to precipitate a white solid, and the precipitate is filtered to obtain PEGDA;

[0010] (3) Preparation of ZIF@PEGDA interfacial floating microspheres: Mix PEGDA with a photoinitiator, then add ZIF and hollow microspheres. After mixing evenly, pour the mixture into a light printing tube, irradiate it with ultraviolet light, and perform 3D printing using a bio-3D printer to obtain photocured ZIF@PEGDA interfacial floating microspheres.

[0011] In a preferred embodiment of the present invention, in step (1), the concentration of zinc acetate dihydrate in the dimethylformamide solution of zinc acetate dihydrate is 0.1 - 0.3 M, the concentration of imidazole-2-carboxaldehyde (2-ICA) in the dimethylformamide solution of imidazole-2-carboxaldehyde is 0.05 - 0.15 M, and the volume ratio of the dimethylformamide solution of zinc acetate dihydrate to the dimethylformamide solution of imidazole-2-carboxaldehyde (2-ICA) is 1:12 - 3:1.

[0012] In a preferred embodiment of the present invention, in step (1), the volume ratio of the added dimethylformamide to the dimethylformamide solution of zinc acetate dihydrate and the dimethylformamide solution of imidazole-2-carboxaldehyde (2-ICA) is 2 - 3:1.

[0013] In a preferred embodiment of the present invention, in step (1), the reaction time is 3 - 7 min, the centrifugation speed is 7000 - 9000 rpm, the centrifugation time is 10 - 20 min, the vacuum drying activation temperature is 70 - 90 °C, and the activation time is 20 - 30 h.

[0014] In a preferred embodiment of the present invention, in step (2), the molar ratio of acryloyl chloride to PEG6000 is 3 - 5:1.

[0015] In a preferred embodiment of the present invention, in step (2), the acid-binding agent is an alkali metal carbonate, preferably K 2 CO 3 or Na 2 CO 3 etc., and the amount of the acid-binding agent is equivalent to the molar amount of acryloyl chloride.

[0016] In a preferred embodiment of the present invention, in step (2), the reaction time is 20 - 30 h.

[0017] In a preferred embodiment of the present invention, in step (3), the volume ratio of PEGDA to the photoinitiator is 2:1 - 1:4, the concentration of PEGDA is 20 - 40 wt%, the concentration of the photoinitiator is 0.5 - 0.15 g / mL, the mass ratio of ZIF to the hollow microspheres is 1:1.5 - 2.5, and the mass ratio of the mixture of PEGDA and the photoinitiator to ZIF and the hollow microspheres is 5 - 9:1.

[0018] In a preferred embodiment of the present invention, in step (4), the ultraviolet light illumination conditions are such that the light intensity is 4-6 mW / cm 2 , and the wavelength is 365 nm.

[0019] To achieve the above object, the second technical solution of the present invention is: a ZIF@PEGDA interfacial floating microsphere prepared by the above preparation method.

[0020] To achieve the above object, the third technical solution of the present invention is: an application of a ZIF@PEGDA interfacial floating microsphere in the degradation of oil pollution in various water areas such as rivers, lakes, and seas.

[0021] Compared with the existing lipase oil pollution degradation technologies such as ultrasonic-assisted degradation, genetic modification, and microemulsion, the present invention has the following

[0022] beneficial effects:

[0023] 1. The ZIF mimetic enzyme designed according to the active site of lipase in the present invention has high lipase activity, and at the same time has excellent acid, alkali, and high temperature stability, and can still maintain a high decomposition efficiency under harsh environments;

[0024] 2. The ZIF@PEGDA interfacial floating microspheres prepared in the present invention can make all the degradation reactions of the ZIF mimetic enzyme occur at the oil-water interface, accelerate the interfacial reaction, and thus improve the degradation efficiency of oils and fats;

[0025] 3. The solidified interfacial floating microspheres of the present invention have acid, alkali, and high temperature stability, can be generally applied to the degradation of oil pollution in various water areas such as rivers, lakes, and seas, and can be salvaged and recycled, realizing multiple reuse, thereby reducing the industrial application cost of oil degradation, being green and environmentally friendly;

[0026] 4. The ZIF@PEGDA interfacial floating microspheres prepared in the present invention can be flexibly set to a specific shape according to application requirements during the 3D printing process, providing a new strategy for enhancing the interfacial reaction between nanoenzymes and bioenzymes. Description of the Drawings

[0027] Figure 1 It is a comparison result diagram of the acid and alkali resistance characteristics of the ZIF mimetic enzyme and lipase in Example 1;

[0028] Figure 2 It is a comparison result diagram of the high temperature resistance characteristics of the ZIF mimetic enzyme and lipase in Example 1;

[0029] Figure 3 It is a comparison result diagram of the activities of the ZIF mimetic enzyme and the ZIF@PEGDA interfacial floating microsphere;

[0030] Figure 4It is a graph showing the comparison results of the thermal stabilities of ZIF mimetic enzyme and ZIF@PEGDA interfacial floating microspheres;

[0031] Figure 5 It is a graph showing the comparison results of the activities of ZIF and ZIF floating microspheres at different incubation times. (a) shows the tolerance to strong acid and anti-denaturation at pH = 2, and (b) shows the tolerance to strong base and anti-denaturation at pH = 11;

[0032] Figure 6 It is the result of the repetitive activity determination of ZIF@PEGDA interfacial floating microspheres;

[0033] Figure 7 It is the change curve of the enzyme activity of ZIF@PEGDA interfacial floating microspheres with the storage time.

[0034] Figure 8 It is a graph showing the comparison results of the activities of lipase and ZIF@PEGDA interfacial floating microspheres;

[0035] Figure 9 It is a picture of ZIF@PEGDA interfacial floating microspheres floating on the oil-water two-phase;

[0036] Figure 10 It is a picture of the 3D printed specific grid shape of ZIF@PEGDA interfacial floating microspheres. Detailed implementation manners

[0037] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments. However, the protection scope of the present invention is not limited to these embodiments.

[0038] Example 1

[0039] A kind of ZIF@PEGDA interfacial floating microsphere is prepared by the following method, including the following steps:

[0040] (1) Preparation of ZIF mimetic enzyme: First, 0.26346 g of zinc acetate dihydrate and 0.057654 g of imidazole-2-carboxaldehyde are respectively dissolved in 6 mL of dimethylformamide, and then Zn(CH 3 COOH) 2 ·2H 2A solution of O(0.2M, 6mL) in dimethylformamide (DMF) was added to a DMF solution containing imidazole acid-2-carboxaldehyde (2-ICA) (0.1M, 6mL). After reacting for 5 min, 30 mL of DMF was added to the reaction mixture to further stabilize the spheres. Then, the mixture was centrifuged at 8000 rpm for 10 min to collect the precipitate, and the precipitate was washed with 30 mL of anhydrous ethanol and centrifuged again at 8000 rpm for 15 min. The washing process was repeated 5 times. The obtained precipitate after washing was dried and activated under vacuum at 80 °C for 24 h. The dried product was ground to obtain ZIF powder, which was stored in the dark at 4 °C.

[0041] (2) Preparation of PEGDA: 20 g of PEG6000 was dissolved in 100 mL of dichloromethane in a 250 mL single-necked flask, and then K 2 CO 3 was added as an acid-binding agent. A dichloromethane solution of acryloyl chloride was slowly added dropwise at room temperature, and the molar ratio of acryloyl chloride to PEG6000 was equal to 4:1. After reacting for 24 h, the reaction mixture was washed with water to remove the excess acryloyl chloride and inorganic salts, and then separated by liquid-liquid extraction. The organic phase was dried over anhydrous magnesium sulfate and concentrated by rotary evaporation. The concentrated solution was added to n-hexane to precipitate a white solid, and the product was obtained by filtration.

[0042] (3) Preparation of ZIF@PEGDA interfacial floating microspheres: 0.3 g of PEGDA with a concentration of 30 wt% was mixed with 1 g of a photoinitiator with a concentration of 1 mg / mL, and then 0.07 g of ZIF and 0.15 g of hollow microspheres were added thereto. After mixing evenly, the mixture was poured into a light-printing tube and irradiated with ultraviolet light at a light intensity of 5 mW / cm 2 and a wavelength of 365 nm. The ZIF@PEGDA interfacial floating microspheres were obtained by 3D printing using a bio-3D printer.

[0043] The acid and alkali resistance and high temperature resistance of the ZIF mimetic enzyme prepared in step (1) were compared with those of lipase. The effects of pH on the activities of free lipase and free ZIF were respectively tested in buffer solutions with pH values of 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, and 11.0 at 40 °C. The test results are as Figure 1 shown. Among them, the buffer solutions with pH values of 2.0 and 3.0 were glycine-hydrochloric acid, the buffer solutions with pH values of 4.0, 5.0, and 6.0 were citric acid-sodium citrate, the buffer solutions with pH values of 8.0 and 9.0 were Tris-HCL, and the buffer solutions with pH values of 10.0 and 11.0 were sodium carbonate-sodium bicarbonate. The concentration of all buffer solutions was 1 M.

[0044] (1) Comparison of acid and alkali resistance between ZIF mimetic enzyme and lipase

[0045] From Figure 1 it can be seen that the optimal pH of lipase is around 5. When the pH deviates from 5, the activity decreases significantly; the activity of free ZIF is stable in the range of pH 2-9, and slightly increases at pH 10-11. Therefore, ZIF has good acid and alkali tolerance and still has high activity in strong acid and strong alkali environments. The ZIF enzyme and lipase were tested for their enzymatic activity by reacting with olive oil at temperatures of 20, 40, 60, 80, 100 °C and pH = 7. The test results are as Figure 2 shown.

[0046] (2) Comparison of the high temperature tolerance characteristics between ZIF mimetic enzyme and lipase

[0047] From Figure 2 it can be seen that the optimal temperature of lipase is around 40 °C. When the temperature deviates from 40 °C, the activity decreases significantly, and it approaches inactivation at temperatures above 80 °C; the activity of free ZIF is stable in the range of 20-80 °C, and shows an increasing trend at 90-100 °C. Therefore, ZIF has good high temperature tolerance and still has high activity in high temperature environments.

[0048] (3) Comparison of the activities between ZIF mimetic enzyme and ZIF@PEGDA interfacial floating microspheres

[0049] After reacting ZIF and floating microspheres containing the same mass of ZIF at 40 °C and pH = 7, their activities were tested. The test results are as Figure 3 shown.

[0050] From Figure 3 it can be seen that under the same conditions, the activity of ZIF embedded in PEGDA is 6.61 times higher than that of free ZIF.

[0051] (4) Thermal stability of ZIF mimetic enzyme and ZIF@PEGDA interfacial floating microspheres

[0052] In an environment of 90 °C and pH = 7, 7 equal amounts were taken respectively. The ZIF solution and ZIF floating microspheres were incubated in a water bath for 1-6 hours, and the enzyme activities of the above three experimental groups were measured and recorded every hour, and the residual activity was calculated. The test results are as Figure 4 shown.

[0053] From Figure 4 it can be seen that under different incubation times, the activities of ZIF and ZIF floating microspheres are maintained stable, and both have good thermal stability.

[0054] (5) Strong acid and strong alkali tolerance and anti-denaturation of ZIF@PEGDA interfacial floating microspheres

[0055] Seven equal amounts were taken respectively under the conditions of 40 °C, pH = 2 and 40 °C, pH = 11. The ZIF floating microspheres were incubated in a water bath for 0 - 6 hours, and the enzyme activity of the above three experimental groups was measured and recorded every hour. The test results are as Figure 5 shown. (a) is for strong acid tolerance and anti-denaturation at pH = 2, and (b) is for strong base tolerance and anti-denaturation at pH = 11.

[0056] From Figure 5 it can be seen that at different incubation times, the activities of ZIF and ZIF floating microspheres are maintained stably, and both have good thermal stability.

[0057] (6) Repeatability of ZIF@PEGDA interfacial floating microspheres

[0058] Under the optimal conditions, a ten-time reusability experiment was carried out on the immobilized enzyme. That is, after each reaction ended, the immobilized enzyme was fished out, washed with Tris-HCl solution at pH = 7.0, and then fresh reaction solution was added again for the next cycle. The enzyme activity of each cycle was tested. The test results are as Figure 6 shown. From Figure 6 it can be seen that the ZIF floating microspheres still have 80% residual enzyme activity after 10 cycles, with good repeat performance, thus reducing the industrial application cost of oil degradation and being green and environmentally friendly.

[0059] (7) Activity stability of ZIF@PEGDA interfacial floating microspheres with storage time

[0060] Seven equal amounts of ZIF floating microspheres were taken respectively and stored at 4 °C for 1, 2, 3, 5, 10, 15, 20, 25, 30 d, and then taken out to test their enzyme activities. The test results are as Figure 7 shown. From Figure 7 it can be seen that the ZIF@PEGDA interfacial floating microspheres still have more than 90% enzyme activity after storage for 30 d, with good stability.

[0061] (8) Optimization scheme for improving the activity of ZIF@PEGDA interfacial floating microspheres

[0062] ① Before putting into the reaction, incubate the ZIF floating microspheres at 90 °C for 3 h, and then take them out and put them into the reaction, which can significantly improve the degradation activity of the floating microspheres.

[0063] ② Adding a certain amount of activated carbon to the embedding system can improve the adsorption capacity of the microspheres for oil, thereby improving the oil degradation efficiency.

[0064] The ZIF@PEGDA interfacial floating microspheres prepared in this example can be flexibly set to a specific shape according to application requirements during the 3D printing process, providing a new strategy for enhancing the interfacial reaction between nanoenzymes and bioenzymes, such asFigure 10 as shown

[0065] Example 2

[0066] Application of the ZIF@PEGDA interfacial floating microspheres prepared in Example 1 in the degradation of oil pollution in various water areas such as rivers, lakes, ports, and oceans.

[0067] The ZIF mimetic enzyme designed according to the lipase active site has higher enzyme activity than lipase, and at the same time has excellent acid, alkali and high temperature stability. As Figure 5 and Figure 8 shown, it can still maintain a high decomposition efficiency in harsh environments such as rivers, lakes, ports, and oceans.

[0068] The ZIF@PEGDA interfacial floating microspheres can make all ZIF mimetic enzyme degradation reactions occur at the oil-water interface in various water areas, accelerate the interfacial reaction, and thus improve the degradation efficiency of oil. As Figure 9 shown, the ZIF@PEGDA interfacial floating microspheres float on the oil-water two-phase.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing ZIF@PEGDA interface floating microspheres, characterized in that: The steps include: (1) Preparation of ZIF mimetic enzyme: Add a dimethylformamide solution of zinc acetate dihydrate to a dimethylformamide solution of imidazole-2-carboxaldehyde (2-ICA) to react, add dimethylformamide, and then collect the precipitate by centrifugation. The precipitate is then washed, centrifuged, cleaned, vacuum dried, activated, and finally ground to obtain ZIF powder. (2) Preparation of PEGDA: PEG6000 was dissolved in dichloromethane, and then an acid-binding agent was added. Then, a dichloromethane solution of acryloyl chloride was slowly added dropwise to react. After the reaction, the excess acryloyl chloride and inorganic salt were washed off, and the liquids were separated. The organic phase was dried over anhydrous magnesium sulfate and concentrated by rotary evaporation. The concentrate was added to n-hexane to precipitate a white solid, which was filtered to obtain PEGDA. (3) Preparation of ZIF@PEGDA interface floating microspheres: PEGDA was mixed with a photoinitiator and then ZIF and hollow microspheres were added. After mixing evenly, the mixture was poured into a photoprinting tube, irradiated with ultraviolet light and 3D printed using a biological 3D printer to obtain photocured ZIF@PEGDA interface floating microspheres.

2. The method for preparing ZIF@PEGDA interface floating microspheres according to claim 1, characterized in that: In the step (1), the concentration of zinc acetate dihydrate in the dimethylformamide solution of zinc acetate dihydrate is 0.1-0.3M, the concentration of imidazole-2-carboxaldehyde in the dimethylformamide solution of imidazole-2-carboxaldehyde is 0.05-0.15M, the volume ratio of the dimethylformamide solution of zinc acetate dihydrate to the dimethylformamide solution of imidazole-2-carboxaldehyde is 1:12-3:1, and the volume ratio of the added dimethylformamide to the dimethylformamide solution of zinc acetate dihydrate and the dimethylformamide solution of imidazole-2-carboxaldehyde is 2-3:

1.

3. The method for preparing ZIF@PEGDA interface floating microspheres according to claim 1, characterized in that: In the step (1), the reaction time is 3-7 minutes, the centrifugal speed is 7000-9000 rpm, the centrifugal time is 10-20 minutes, the vacuum drying activation temperature is 70-90° C., and the activation time is 20-30 hours.

4. The method for preparing ZIF@PEGDA interface floating microspheres according to claim 1, characterized in that: In the step (2), the molar ratio of acryloyl chloride to PEG6000 is 3-5:

1.

5. The method for preparing ZIF@PEGDA interface floating microspheres according to claim 1, characterized in that: In the step (2), the acid binding agent is an alkali metal carbonate, and the molar amount of the acid binding agent is equivalent to that of acryloyl chloride.

6. The method for preparing ZIF@PEGDA interface floating microspheres according to claim 1, characterized in that: The reaction time in step (2) is 20-30 hours.

7. The method for preparing ZIF@PEGDA interface floating microspheres according to claim 1, characterized in that: In the step (3), the volume ratio of PEGDA to the photoinitiator is 2:1-1:4, the concentration of PEGDA is 20-40wt%, the concentration of the photoinitiator is 0.5-0.15g / mL, the mass ratio of ZIF to the hollow microspheres is 1:1.5-2.5, and the mass ratio of the mixture of PEGDA and the photoinitiator and the mass ratio of ZIF to the hollow microspheres is 5-9:

1.

8. The method for preparing ZIF@PEGDA interface floating microspheres according to claim 1, characterized in that: The ultraviolet light illumination condition in step (4) is a light intensity of 4-6 mW / cm 2 , wavelength is 365nm.

9. ZIF@PEGDA interface floating microspheres prepared by the method for preparing ZIF@PEGDA interface floating microspheres according to any one of claims 1 to 8.

10. Use of the ZIF@PEGDA interfacial floating microspheres as claimed in claim 9 in the degradation of oil pollution in various large water bodies.

Images