High-temperature self-repairing super-hydrophobic MOF sponge as well as preparation method and application thereof
By loading UiO-66-NH2 on the three-dimensional porous sponge and forming a low-surface energy polysiloxane glue layer, a superhydrophobic MOF sponge with high temperature self-healing was prepared, which solved the problem of low oil phase absorption efficiency in oil-water separation and achieved efficient oil-water separation and self-healing ability.
Patent Information
- Application Number
- CN202510792421.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-13
- Publication Date
- 2025-08-19
AI Technical Summary
The existing three-dimensional porous sponges cannot achieve selective oil-water absorption during oil-water separation, resulting in low oil-phase absorption efficiency and lack of self-healing ability.
UiO-66-NH2 was prepared by hydrothermal synthesis method and loaded onto dopamine-modified melamine sponge. A low-surface energy polysiloxane glue layer was formed on the sponge surface to prepare a high-temperature self-healing superhydrophobic MOF sponge.
The superhydrophobicity, self-healing and efficient oil-water separation performance of the sponge are achieved, and it has good cationic dye removal capabilities, and can maintain stability and self-cleaning performance at high temperatures.
Smart Images
Figure CN120504881A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of oil-water separation materials, and specifically discloses a high-temperature self-repairing super-hydrophobic MOF sponge and a preparation method and application thereof. Background Art
[0002] During offshore oilfield exploitation and oil transportation, frequent oil spills have caused enormous losses and damage to the economy and ecological environment. In addition, a large amount of oily wastewater generated by industrial production and people's daily activities is discharged into various water streams. Over time, the chemical components in these oily wastewaters will enter the human body through the water cycle, thereby endangering life and health. The main methods for treating oily wastewater at present include combustion, physical adsorption, bioremediation and membrane treatment technology. Among them, physical adsorption has the advantages of simple operation, low manufacturing / raw material cost and environmental friendliness compared to other treatment methods, which has attracted the attention of researchers.
[0003] The physical adsorption method has certain requirements for the selection of adsorption materials. Therefore, researchers have conducted a lot of research on adsorption materials. Common adsorption materials include sponges, plants, straw and bentonite. Among them, the special three-dimensional network structure of the three-dimensional porous sponge gives it high elasticity and high absorption capacity, making it a commonly used material for efficient oil-water separation. However, the three-dimensional porous sponge does not have oil-water selectivity. It can absorb both the oil phase and the water phase in the oil-water mixture, resulting in a significant reduction in its absorption efficiency for the oil phase. At this point, it is necessary to change its properties to make it a functional superhydrophobic sponge. Summary of the Invention
[0004] To address the technical issues identified in the background section, the present invention provides a green, environmentally friendly, simple, and easy-to-use method. The resulting MOF sponge is a superhydrophobic / superoleophilic material that is resistant to acids and alkalis, corrosion, and extrusion, and exhibits excellent reusability and self-cleaning properties, enabling efficient and continuous oil-water separation. Furthermore, the MOF sponge exhibits excellent selective adsorption of cationic dyes and is self-healing at temperatures up to 250°C.
[0005] Specifically, the present invention provides a method for preparing a high-temperature self-healing superhydrophobic MOF sponge. UiO-66-NH2 is first prepared by hydrothermal synthesis. MS is immersed in an alkaline solution of DA to produce PDA@MS. UiO-66-NH2 is then added and dried to produce UiO-66-NH2@PDA@MS. The sponge is then immersed in a hydrolyzed solution of hexadecyltrimethoxysilane, stirred, washed, and dried to obtain a high-temperature self-healing superhydrophobic MOF sponge.
[0006] The hydrothermal synthesis method for preparing UiO-66-NH2 involves dissolving 70 mg of zirconium chloride, 54 mg of 2-aminoterephthalic acid, and 8 mL of acetic acid in 65 mL of DMF and sonicating the mixture in a beaker for 30 minutes. The mixture is then transferred to a 100 mL polytetrafluoroethylene reactor and reacted at 120°C for 24 hours. The resulting reaction solution is centrifuged at 10,000 rpm for 3 minutes, and the precipitate is collected and washed three times with DMF and then with anhydrous ethanol. The solid is then placed in a vacuum drying oven at 90°C for 12 hours to yield pale yellow UiO-66-NH2 crystals.
[0007] The preparation method of high-temperature self-repairing super-hydrophobic MOF sponge is as follows:
[0008] (1) Cut the untreated MS into 1×1×1cm 3 The cube was ultrasonically cleaned with ethanol and deionized water to remove impurities on the MS surface. After cleaning, the sponge was placed in a blast drying oven to dry for later use.
[0009] (2) Dopamine and pretreated MS were added to 125 mL of Tris-HCl buffer (pH = 8.5) and stirred at 200 rpm using a magnetic stirrer at room temperature for 24 h. After stirring, the MS with the PDA layer on its surface was removed and repeatedly rinsed with anhydrous ethanol and deionized water until the solution was clear. Finally, the sponge was placed in a forced air drying oven at 60°C for 12 h to obtain a PDA@MS sample.
[0010] (3) Add 0.1 g of sodium hydroxide powder and 40 mL of anhydrous ethanol to a beaker and stir for 20 min until the sodium hydroxide is completely dissolved. Then, add UiO-66-NH2 powder and stir vigorously at room temperature for 30 min to fully disperse the UiO-66-NH2 in the solution.
[0011] (4) PDA@MS was immersed in the above dispersion and stirred at 180 rpm for 6 h at room temperature. After stirring, it was repeatedly washed with anhydrous ethanol and dried in a forced air drying oven at 60°C for 6 h to obtain the UiO-66-NH2@PDA@MS sample.
[0012] (5) Add 0.3 mL of acetic acid and 30 mL of ethanol solution (95%) to a beaker and stir evenly. Slowly add hexadecyltrimethoxysilane (HDTMS) dropwise and continue stirring at room temperature for 3 h. Finally, add UiO-66-NH2@PDA@MS and continue stirring at 180 rpm at room temperature for dip coating. After stirring, wash repeatedly with anhydrous ethanol and dry in a forced air drying oven at 60 ° C for 6 h to obtain a high-temperature self-healing superhydrophobic MOF sponge UiO-66-NH2@PDA@MS.
[0013] The mass ratio of dopamine hydrochloride DA to UiO-66-NH2 is 0.5-1.5:1-2, the amount of the hydrophobic agent is 0.5-1.5 mL, and the stirring and dipping time after the hydrophobic agent is added to the sponge is 2-4 h.
[0014] Compared with the prior art, the present invention has the following advantages:
[0015] 1. The super-hydrophobic modification process of the present invention is simple, convenient, low-cost, and the raw materials are non-toxic and harmless, and green and environmentally friendly.
[0016] 2. The sponge of the present invention has excellent superhydrophobicity (water contact angle of 156.2°), high oil absorption capacity (73.2-164.7 g / g), and good cationic dye removal ability (more than 95%).
[0017] 3. The super-hydrophobic melamine sponge prepared by the present invention has excellent oil-water separation performance, reusability, environmental stability, self-cleaning and self-repairing properties. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 (a) is a state diagram of water droplets and oil droplets on the surface of the original sponge and the composite sponge of Example 1 of the present invention, (b) is a picture of the water contact angle of the composite sponge of Example 1 of the present invention, (c) is a state diagram of a water droplet on the cross-section of the composite sponge of Example 1 of the present invention, (d) is a picture of the silver mirror phenomenon of the composite sponge of Example 1 of the present invention in water, (e) is a state diagram of the original sponge sinking in water and the composite sponge of Example 1 of the present invention floating on water, and (f) is a state diagram of a water droplet on the composite sponge of Example 1 of the present invention changing over time.
[0019] Figure 2 2 are FESEM comparison images of the original sponge and the composite sponge of Example 1 of the present invention.
[0020] Figure 3 (a) Comparison of WCA and oil absorption of composite sponges prepared with different mass ratios of DA and MOF, (b) Changes in WCA of composite sponges prepared with different HDTMS immersion times.
[0021] Figure 4 This is the absorption capacity of the composite sponge of Example 1 of the present invention for different organic solvents / oils.
[0022] Figure 5 This is the change process of the water contact angle of the composite sponge in Example 1 of the present invention after 10 etching-high-temperature self-repairing cycles.
[0023] Figure 6 This is a graph showing the hydrophobic angle data of the composite sponge of Example 1 of the present invention after being soaked in different salt concentrations for 12 hours.
[0024] Figure 7 This is a graph showing the hydrophobic angle data of the composite sponge of Example 1 of the present invention after being soaked in different pH conditions for 12 hours.
[0025] Figure 8 It is a process flow chart of the present invention. DETAILED DESCRIPTION
[0026] The present invention will be further described below with reference to the examples, but is not limited thereto.
[0027] 1. When the composite sponge reaches superhydrophobicity, it is necessary to ensure that the oil absorption is higher and the cationic dye adsorption effect is better.
[0028] 2. Oil / organic solution absorption capacity test
[0029] The oil absorption performance of the prepared composite sponge was tested by soaking it in various oils / organic solvents (such as petroleum ether, n-hexane, n-octane, benzene, toluene, heavy oil, DMF, and chloroform) for 5 minutes. First, the composite sponge was weighed and recorded as m1. It was then placed in 25 mL of oil or organic solvent and soaked for 5 minutes. After reaching mass absorption equilibrium, the sponge was removed and drained (approximately 3 seconds) until no excess solvent remained on the surface. The sponge was removed and weighed as m2. The saturated absorption capacity of the sponge is represented by K and can be calculated using the following formula:
[0030] K=(m2-m1) / m1
[0031] 3. Oil-water separation efficiency and reusability test
[0032] The reusability of the composite sponge was tested by repeated absorption-extrusion cycles. The mass of the sponge before oil absorption was recorded as m1. The sponge was immersed in oil or organic solvent at ambient temperature for 5 minutes to saturate the sponge with absorption. The mass of the sponge at this time was recorded as m2. The saturated sponge was placed in a syringe and the syringe was manually pushed to compress the sponge until all the oil adsorbed by the sponge was squeezed out and no oil droplets were separated. The mass of the sponge after desorption was recorded as m3. It was placed in an oven at 60°C for drying for the next cycle. The oil-water separation efficiency was recorded as η, that is:
[0033] η=(m2-m3) / (m2-m1)
[0034] 4. Environmental stability test
[0035] The composite sponge was soaked in NaCl solutions with concentrations of 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0% for 12 hours. The sponge was removed, rinsed with anhydrous ethanol, dried, and the water contact angle was measured. The composite sponge was soaked in acidic and alkaline solutions with pH values of 1, 3, 5, 7, 9, 11, and 13 for 12 hours. The sponge was removed, rinsed with anhydrous ethanol, dried, and the water contact angle was measured.
[0036] In the above embodiments 2, 3, and 4, three composite sponges were soaked and the average value of the three groups of data was taken to ensure the accuracy of the data.
[0037] 5. Self-repair performance test
[0038] The coating was etched using an air plasma cleaner to simulate long-term oxidative damage. After one minute of etching in the air plasma cleaner, the sponge's surface transitioned from superhydrophobic to hydrophilic. The sponge was then placed in a 250°C forced air drying oven for 30 minutes. After drying, its water contact angle was measured. The sponge was then subjected to 10 cycles of air plasma etching and high-temperature self-repair. The water contact angle was measured after each cycle to evaluate the sponge's cyclic self-repair performance.
[0039] 6. Cationic dye adsorption performance test
[0040] The composite sponge was placed in a methylene blue dye (concentration of 20 mg / L) for 6 hours. After adsorption saturation, the dye absorbance before and after adsorption was measured using a UV-visible spectrophotometer. The adsorption efficiency of the sponge was calculated to evaluate its cationic dye adsorption performance.
[0041] Example 1
[0042] (1) Cut the untreated MS into 1×1×1cm 3 The cube was ultrasonically cleaned with ethanol and deionized water for 30 min each to remove impurities on the MS surface. After cleaning, the sponge was placed in a forced air drying oven at 60°C for 12 h.
[0043] (2) Dissolve 70 mg of zirconium chloride, 54 mg of 2-aminoterephthalic acid, and 8 mL of acetic acid in 65 mL of DMF and dissolve them in a beaker under ultrasonication for 30 min. Then transfer the mixture to a 100 mL polytetrafluoroethylene reactor and react at 120 ° C for 24 h. The resulting reaction solution is centrifuged at 10,000 rpm for 3 min, collect the precipitate, and wash it three times with DMF and anhydrous ethanol respectively. Place the solid in a vacuum drying oven at 90 ° C for 12 h to obtain light yellow UiO-66-NH2 crystals;
[0044] (3) 0.1 g of dopamine and pretreated MS were added to 125 mL of Tris-HCl buffer (pH = 8.5) and stirred at 200 rpm using a magnetic stirrer at room temperature for 24 h. After stirring, the MS with the PDA layer on the surface was removed and repeatedly rinsed with anhydrous ethanol and deionized water until the solution was clear. Finally, the sponge was placed in a forced air drying oven at 60°C for 12 h to obtain a PDA@MS sample.
[0045] (4) Add 0.1g of sodium hydroxide powder and 40mL of anhydrous ethanol to a beaker and stir for 20 minutes until the sodium hydroxide is completely dissolved. Then, add 0.15g of UiO-66-NH2 powder and stir vigorously at room temperature for 30 minutes to fully disperse UiO-66-NH2 in the solution. Immerse PDA@MS in the above dispersion and stir continuously at 180rpm for 6 hours at room temperature. After stirring, wash repeatedly with anhydrous ethanol until there is no solid powder residue on the surface of the sponge, and dry it in a blast drying oven at 60°C for 6 hours to obtain a UiO-66-NH2@PDA@MS sample;
[0046] (5) Add 0.3 mL of acetic acid and 30 mL of 95% ethanol solution to a beaker and stir evenly. Add 1 mL of hexadecyltrimethoxysilane (HDTMS) dropwise per second and continue stirring at room temperature for 3 h. Finally, add UiO-66-NH2@PDA@MS and continue stirring at 180 rpm for 3 h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a forced air drying oven at 60°C for 6 h to obtain HDTMS@UiO-66-NH2@PDA@MS.
[0047] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 77.9 g / g and 164.7 g / g respectively, the hydrophobic angle is 156.2°, and the adsorption effect of methylene blue dye is strong, with the adsorption efficiency reaching more than 95%. The dye solution becomes clear after adsorption.
[0048] Example 2
[0049] (1) The MS preparation steps are the same as step (1) in Example 1;
[0050] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0051] (3) 0.05 g of dopamine and pretreated MS were added to 125 mL of Tris-HCl buffer (pH = 8.5) and stirred at 200 rpm using a magnetic stirrer at room temperature for 24 h. After stirring, the MS with the PDA layer on the surface was removed and repeatedly rinsed with anhydrous ethanol and deionized water until the solution was clear. Finally, the sponge was placed in a 60°C forced air drying oven for 12 h to obtain a PDA@MS sample.
[0052] (4) The preparation steps of UiO-66-NH2@PDA@MS are the same as step (4) in Example 1;
[0053] (5) The preparation steps of HDTMS@UiO-66-NH2@PDA@MS are the same as those in step (5) of Example 1;
[0054] The saturated oil absorption of the composite sponge for n-hexane and chloroform were 79.4 g / g and 166.8 g / g, respectively, and the hydrophobic angle was 152.7°. The adsorption effect of methylene blue dye was weak, with an adsorption efficiency of 68%. The dye solution was relatively turbid after adsorption.
[0055] Example 3
[0056] (1) The MS preparation steps are the same as step (1) in Example 1;
[0057] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0058] (3) 0.15 g of dopamine and pretreated MS were added to 125 mL of Tris-HCl buffer (pH = 8.5) and stirred at 200 rpm using a magnetic stirrer at room temperature for 24 h. After stirring, the MS with the PDA layer on the surface was removed and repeatedly rinsed with anhydrous ethanol and deionized water until the solution was clear. Finally, the sponge was placed in a forced air drying oven at 60°C for 12 h to obtain a PDA@MS sample.
[0059] (4) The preparation steps of UiO-66-NH2@PDA@MS are the same as step (4) in Example 1;
[0060] (5) The preparation steps of HDTMS@UiO-66-NH2@PDA@MS are the same as those in step (5) of Example 1;
[0061] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 73.8 g / g and 161.1 g / g respectively, the hydrophobic angle is 156.1°, and the adsorption effect of methylene blue dye is strong, with the adsorption efficiency reaching more than 95%. The dye solution becomes clear after adsorption.
[0062] Example 4
[0063] (1) The MS preparation steps are the same as step (1) in Example 1;
[0064] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0065] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0066] (4) Add 0.1g of sodium hydroxide powder and 40mL of anhydrous ethanol to a beaker and stir for 20min until the sodium hydroxide is completely dissolved. Then, add 0.1g of UiO-66-NH2 powder and stir vigorously at room temperature for 30min to fully disperse UiO-66-NH2 in the solution. Immerse PDA@MS in the above dispersion and stir continuously at 180rpm for 6h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a blast drying oven at 60℃ for 6h to obtain the UiO-66-NH2@PDA@MS sample;
[0067] (5) The preparation steps of HDTMS@UiO-66-NH2@PDA@MS are the same as those in step (5) of Example 1;
[0068] The saturated oil absorption of the composite sponge for n-hexane and chloroform were 79.6 g / g and 165.5 g / g, respectively, and the hydrophobic angle was 153.2°. The adsorption effect of methylene blue dye was weak, with an adsorption efficiency of 60%. The dye solution was relatively turbid after adsorption.
[0069] Example 5
[0070] (1) The MS preparation steps are the same as step (1) in Example 1;
[0071] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0072] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0073] (4) Add 0.1g of sodium hydroxide powder and 40mL of anhydrous ethanol to a beaker and stir for 20 minutes until the sodium hydroxide is completely dissolved. Then, add 0.125g of UiO-66-NH2 powder and stir vigorously at room temperature for 30 minutes to fully disperse UiO-66-NH2 in the solution. Immerse PDA@MS in the above dispersion and stir continuously at 180rpm for 6 hours at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a blast drying oven at 60°C for 6 hours to obtain a UiO-66-NH2@PDA@MS sample;
[0074] (5) The preparation steps of HDTMS@UiO-66-NH2@PDA@MS are the same as those in step (5) of Example 1;
[0075] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 78.8 g / g and 165.2 g / g respectively, and the hydrophobic angle is 153.4°. It has a good adsorption effect on methylene blue dye with an adsorption efficiency of 80%. The dye solution is slightly turbid after adsorption.
[0076] Example 6
[0077] (1) The MS preparation steps are the same as step (1) in Example 1;
[0078] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0079] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0080] (4) Add 0.1g of sodium hydroxide powder and 40mL of anhydrous ethanol to a beaker and stir for 20 minutes until the sodium hydroxide is completely dissolved. Then, add 0.175g of UiO-66-NH2 powder and stir vigorously at room temperature for 30 minutes to fully disperse UiO-66-NH2 in the solution. Immerse PDA@MS in the above dispersion and stir continuously at 180rpm for 6 hours at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a blast drying oven at 60°C for 6 hours to obtain a UiO-66-NH2@PDA@MS sample;
[0081] (5) The preparation steps of HDTMS@UiO-66-NH2@PDA@MS are the same as those in step (5) of Example 1;
[0082] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 76.8 g / g and 163.5 g / g respectively, the hydrophobic angle is 156.0°, and the adsorption effect of methylene blue dye is strong, with the adsorption efficiency reaching more than 95%. The dye solution becomes clear after adsorption.
[0083] Example 7
[0084] (1) The MS preparation steps are the same as step (1) in Example 1;
[0085] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0086] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0087] (4) Add 0.1g sodium hydroxide powder and 40mL anhydrous ethanol to a beaker and stir for 20min until the sodium hydroxide is completely dissolved. Then, add 0.2g UiO-66-NH2 powder and stir vigorously at room temperature for 30min to fully disperse UiO-66-NH2 in the solution. Immerse PDA@MS in the above dispersion and stir continuously at 180rpm for 6h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a blast drying oven at 60℃ for 6h to obtain the UiO-66-NH2@PDA@MS sample;
[0088] (5) The preparation steps of HDTMS@UiO-66-NH2@PDA@MS are the same as those in step (5) of Example 1;
[0089] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 75.2 g / g and 158.7 g / g respectively, the hydrophobic angle is 154.5°, and the adsorption effect of methylene blue dye is strong, with an adsorption efficiency of more than 95%. The dye solution becomes clear after adsorption.
[0090] Example 8
[0091] (1) The MS preparation steps are the same as step (1) in Example 1;
[0092] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0093] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0094] (4) The preparation steps of UiO-66-NH2@PDA@MS are the same as step (4) in Example 1;
[0095] (5) Add 0.3 mL of acetic acid and 30 mL of 95% ethanol solution to a beaker and stir evenly. Slowly add 0.5 mL of hexadecyltrimethoxysilane (HDTMS) dropwise per second and continue stirring at room temperature for 3 h. Finally, add UiO-66-NH2@PDA@MS and continue stirring at 180 rpm for 3 h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a 60°C air drying oven for 6 h to obtain HDTMS@UiO-66-NH2@PDA@MS.
[0096] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 78.1 g / g and 165.0 g / g respectively, the hydrophobic angle is 151.8°, and the adsorption effect of methylene blue dye is strong, with the adsorption efficiency reaching more than 95%. The dye solution becomes clear after adsorption.
[0097] Example 9
[0098] (1) The MS preparation steps are the same as step (1) in Example 1;
[0099] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0100] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0101] (4) The preparation steps of UiO-66-NH2@PDA@MS are the same as step (4) in Example 1;
[0102] (5) Add 0.3 mL of acetic acid and 30 mL of 95% ethanol solution to a beaker and stir evenly. Slowly add 1.5 mL of hexadecyltrimethoxysilane (HDTMS) dropwise per second and continue stirring at room temperature for 3 h. Finally, add UiO-66-NH2@PDA@MS and continue stirring at 180 rpm for 3 h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a 60°C forced air drying oven for 6 h to obtain HDTMS@UiO-66-NH2@PDA@MS.
[0103] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 77.6 g / g and 163.8 g / g respectively, the hydrophobic angle is 154.8°, and the adsorption effect of methylene blue dye is strong, with the adsorption efficiency reaching more than 95%. The dye solution becomes clear after adsorption.
[0104] Example 10
[0105] (1) The MS preparation steps are the same as step (1) in Example 1;
[0106] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0107] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0108] (4) The preparation steps of UiO-66-NH2@PDA@MS are the same as step (4) in Example 1;
[0109] (5) Add 0.3 mL of acetic acid and 30 mL of 95% ethanol solution to a beaker and stir evenly. Slowly add 1 mL of hexadecyltrimethoxysilane (HDTMS) dropwise per second and continue stirring at room temperature for 3 h. Finally, add UiO-66-NH2@PDA@MS and continue stirring at 180 rpm for 2 h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a 60°C forced air drying oven for 6 h to obtain HDTMS@UiO-66-NH2@PDA@MS.
[0110] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 78.1 g / g and 164.9 g / g respectively, the hydrophobic angle is 154.1°, and the adsorption effect of methylene blue dye is strong, with the adsorption efficiency reaching more than 95%. The dye solution becomes clear after adsorption.
[0111] Example 11
[0112] (1) The MS preparation steps are the same as step (1) in Example 1;
[0113] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0114] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0115] (4) The preparation steps of UiO-66-NH2@PDA@MS are the same as step (4) in Example 1;
[0116] (5) Add 0.3 mL of acetic acid and 30 mL of 95% ethanol solution to a beaker and stir evenly. Slowly add 1 mL of hexadecyltrimethoxysilane (HDTMS) dropwise per second and continue stirring at room temperature for 3 h. Finally, add UiO-66-NH2@PDA@MS and continue stirring at 180 rpm for 4 h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a 60°C forced air drying oven for 6 h to obtain HDTMS@UiO-66-NH2@PDA@MS.
[0117] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 77.6 g / g and 164.4 g / g respectively, the hydrophobic angle is 156.2°, and the adsorption effect of methylene blue dye is strong, with the adsorption efficiency reaching more than 95%. The dye solution becomes clear after adsorption.
[0118] Comparative Example 1
[0119] (1) The MS preparation steps are the same as step (1) in Example 1;
[0120] (2) The preparation steps of PDA@MS were the same as those in step (3) of Example 1;
[0121] (3) Add 0.3 mL of acetic acid and 30 mL of 95% ethanol solution to a beaker and stir evenly. Slowly add 1 mL of hexadecyltrimethoxysilane (HDTMS) dropwise at a rate of one drop per second and continue stirring at room temperature for 3 h. Finally, add PDA@MS and continue stirring at 180 rpm for 3 h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a 60°C air drying oven for 6 h to obtain HDTMS@PDA@MS.
[0122] The saturated oil absorption of the composite sponge for n-hexane and chloroform are 81.6 g / g and 167.7 g / g respectively, the hydrophobic angle is 152.4°, and the adsorption effect of methylene blue dye is extremely weak, with an adsorption efficiency of 30%. The color of the dye solution becomes slightly lighter after adsorption.
[0123] Comparative Example 2
[0124] (1) The MS preparation steps are the same as step (1) in Example 1;
[0125] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0126] (3) Add 0.1g of sodium hydroxide powder and 40mL of anhydrous ethanol to a beaker and stir for 20min until the sodium hydroxide is completely dissolved. Then, add 0.15g of UiO-66-NH2 powder and stir vigorously at room temperature for 30min to fully disperse UiO-66-NH2 in the solution. Immerse MS in the above dispersion and stir continuously at 180rpm for 6h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a 60℃ forced air drying oven for 6h to obtain the UiO-66-NH2@MS sample;
[0127] (4) Add 0.3 mL of acetic acid and 30 mL of 95% ethanol solution to a beaker and stir evenly. Slowly add 1 mL of hexadecyltrimethoxysilane (HDTMS) dropwise per second and continue stirring at room temperature for 3 h. Finally, add UiO-66-NH2@MS and continue stirring at 180 rpm for 3 h at room temperature. After stirring, wash repeatedly with anhydrous ethanol and dry in a 60°C forced air drying oven for 6 h to obtain HDTMS@UiO-66-NH2@MS.
[0128] The saturated oil absorption of the composite sponge for n-hexane and chloroform are 82.2 g / g and 168.4 g / g respectively, the hydrophobic angle is 151.8°, and the adsorption effect of methylene blue dye is extremely weak, with an adsorption efficiency of 35%. The color of the dye solution becomes slightly lighter after adsorption.
[0129] Comparative Example 3
[0130] (1) The MS preparation steps are the same as step (1) in Example 1;
[0131] (2) The preparation steps of UiO-66-NH2 are the same as step (2) in Example 1;
[0132] (3) The preparation steps of PDA@MS are the same as step (3) of Example 1;
[0133] (4) The preparation steps of UiO-66-NH2@PDA@MS are the same as step (4) in Example 1;
[0134] The saturated oil absorption of the composite sponge for n-hexane and chloroform is 78.3 g / g and 165.3 g / g respectively, the hydrophobic angle is close to 0°, the adsorption effect of methylene blue dye is strong, the adsorption efficiency can reach more than 95%, and the dye solution becomes clear after adsorption.
Claims
1. A method for preparing a high-temperature self-repairing super-hydrophobic MOF sponge, characterized by: The preparation method of the MOF sponge comprises the following steps: (1) Cut the MS into cubes, clean them with ethanol and deionized water ultrasonically, and dry them for later use; (2) Dissolving zirconium chloride, 2-aminoterephthalic acid, and acetic acid in DMF, dissolving by ultrasonication, and transferring the mixture to a reactor for reaction. The resulting reaction solution is centrifuged to collect the precipitate, which is washed with DMF and anhydrous ethanol. The solid is dried to obtain UiO-66-NH2; (3) adding dopamine DA and the MS prepared in step (1) to a buffer solution, stirring and coating, taking out, rinsing with anhydrous ethanol and deionized water until the solution is clear, and drying to obtain a PDA@MS sample; (4) Sodium hydroxide and anhydrous ethanol were added to a beaker, and UiO-66-NH2 powder was added. The mixture was stirred vigorously at room temperature, and the PDA@MS sample was immersed in the beaker. After continuous stirring, the sample was washed with anhydrous ethanol and dried to obtain the UiO-66-NH2@PDA@MS sample. (5) Add acetic acid and ethanol into a beaker and stir evenly, add hexadecyltrimethoxysilane dropwise, continue stirring, add the sample from step (4), continue stirring, wash with anhydrous ethanol, and dry to obtain a high-temperature self-healing superhydrophobic MOF sponge.
2. The method for preparing a high-temperature self-repairing super-hydrophobic MOF sponge according to claim 1, characterized in that: When preparing UiO-66-NH2 in step (2), the mass volume ratio of zirconium chloride, 2-aminoterephthalic acid, acetic acid and DMF is 70 mg:54 mg:8 mL:65 mL.
3. The method for preparing a high-temperature self-repairing super-hydrophobic MOF sponge according to claim 1, characterized in that: In step (3) and step (4), the mass ratio of dopamine DA to UiO-66-NH2 is 0.5-1.5:1-2, and the DA coating time is 24h.
4. The method for preparing a high-temperature self-repairing super-hydrophobic MOF sponge according to claim 1, wherein: In step (4), 0.1 g of sodium hydroxide powder was dissolved in 40 mL of anhydrous ethanol, and the dipping time of PDA@MS and UiO-66-NH2 powder was 6 h.
5. The method for preparing a high-temperature self-repairing super-hydrophobic MOF sponge according to claim 1, characterized in that: In step (5), 0.3 mL of acetic acid is dissolved in 30 mL of 95% ethanol solution, and the amount of hexadecyltrimethoxysilane used is 0.5-1.5 mL.
6. The method for preparing a high-temperature self-repairing super-hydrophobic MOF sponge according to claim 1, characterized in that: In step (5), hexadecyltrimethoxysilane is stirred for 3 h before adding the sponge and for 2-4 h after adding the sponge.
7. A high-temperature self-healing super-hydrophobic MOF sponge prepared according to the method of claim 1.
8. An application of a high-temperature self-repairing super-hydrophobic MOF sponge prepared by the method according to any one of claims 1 to 6, characterized in that: The high-temperature self-repairing super-hydrophobic MOF sponge is used for oil-water separation or sewage treatment.