Preparation method of fullerol-silver modified PVDF ultrafiltration membrane

Abstract

The application discloses a preparation method of a fullerol-silver modified PVDF ultrafiltration membrane and belongs to the technical field of PVDF ultrafiltration membrane modification. 60 The C 60 (OH) n is oxidized into a hydrophilic C 60 (OH) n by using a tetrabutylammonium hydroxide (TBAH) base type catalysis method, Ag atoms are grown in-situ on the C 60 (OH) n by using an in-situ growth method, and a C 60 (OH) n -Ag compound is obtained. 60 (OH) n The prepared C 60 (OH) n -Ag modified PVDF ultrafiltration membrane has high water permeability, high interception, high porosity and uniform pore size distribution, is a novel C 60 (OH) n -Ag modified PVDF ultrafiltration membrane which integrates good hydrophilic performance, strong tensile capacity, good acid and alkali corrosion resistance, strong antibacterial effect and excellent anti-pollution performance, and has good effects on wastewater treatment containing organic pollutants and is expected to be applied to the field of wastewater treatment.

Description

Technical Field

[0001] This invention belongs to the field of PVDF ultrafiltration membrane modification technology; specifically, it relates to a method for preparing a fullerol-silver modified PVDF ultrafiltration membrane. Background Technology

[0002] Water is an essential resource for human survival, but changes in human production and lifestyles have led to increasingly serious pollution and waste of water bodies in various regions, and exacerbated water shortages. Therefore, wastewater recycling and treatment are imperative. From an economic perspective, reclaimed water is low-cost and conducive to the development of a circular economy and a low-carbon economy; from an ecological perspective, reclaimed water not only meets environmental protection requirements but also reduces resource waste, solves pollution problems, and achieves a virtuous cycle of the water ecosystem.

[0003] Wastewater treatment processes include physical, chemical, biological, and membrane treatment methods. Among these, physical, chemical, and biological methods suffer from drawbacks such as large land area requirements, susceptibility to temperature and seasonal variations, and low separation efficiency, failing to meet the enormous demand for reclaimed water in modern production and daily life. Membrane separation technology, due to its significant advantages of high separation efficiency, low energy consumption, strong selectivity, and wide applicability, has stood out among water treatment methods and has received widespread attention and application. Currently, the membranes that have been researched or developed mainly include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), dialysis, electrodialysis (ED), gas separation pervaporation, etc.

[0004] Ultrafiltration membranes offer advantages in water treatment, including high water flux and retention rate, while also being relatively low in cost. However, due to drawbacks such as poor hydrophilicity, low fouling resistance, high brittleness, and short lifespan, ultrafiltration membrane modification has become a hot research topic. Summary of the Invention

[0005] This invention uses C 60 (OH) n -Ag complexes are used to modify polyvinylidene fluoride (PVDF) ultrafiltration membranes to improve their hydrophilicity, antifouling properties, and antibacterial properties.

[0006] To achieve the above objectives, the present invention provides a method for preparing a fullerol-silver modified PVDF ultrafiltration membrane, which is specifically achieved through the following steps:

[0007] Step 1: Place C 60 (OH) n Dissolved in deionized water and ultrasonically dispersed until homogeneous, yielding C 60 (OH) n Aqueous solution;

[0008] Step 2: Then add silver nitrate and stir for at least 10 minutes. Next, add trisodium citrate and stir in a water bath for at least 2 hours. Centrifuge, discard the supernatant, collect the precipitate, and vacuum dry to obtain C. 60 (OH) n -Ag complex;

[0009] Step 3: Add a certain amount of C to DMF 60 (OH) n -Ag complex, sonicated to disperse it evenly, then PVDF and PVP are added, stirred at a certain temperature for a certain time until a transparent and uniform casting solution is formed, and then allowed to stand to remove bubbles;

[0010] Step 4: Pour the degassed casting solution onto a glass plate, scrape the film with a doctor blade, and after the film is separated and formed, immerse it in a coagulation bath. After the film is completely detached, soak it in distilled water for at least 24 hours to obtain C. 60 (OH) n -Ag-modified PVDF ultrafiltration membrane.

[0011] Further specifying, C described in step one 60 (OH) n It is prepared through the following steps:

[0012] Step 1: Add 0.1g to 0.5g of C 60 Mix with 50mL to 250mL of xylene and stir until the solution turns light purple. Then add 10mL to 50mL of 30% (mass concentration) hydrogen peroxide and 10mL to 50mL of 10% (mass concentration) tetrabutylammonium hydroxide. Bubbles will appear in the solution.

[0013] Step 2: In an oil bath at 60℃~100℃, under magnetic stirring, reflux the reaction for at least 16 hours. The solution will separate into layers. After cooling, collect the lower light brown solution.

[0014] Step 3: Stir in an ice bath. Slowly add a mixed solution of n-hexane and isopropanol with a volume ratio of (1-3):2 to the light brown solution. A brown precipitate will slowly crystallize out. After no more crystals precipitate out, continue stirring in an ice bath for at least 5 minutes. Centrifuge at 8000-10000 rpm for at least 5 minutes. Discard the supernatant. Take the precipitate and wash it at least 3 times with a mixed solution of n-hexane and isopropanol with a volume ratio of (1-3):2. Dry it under vacuum at 50-80°C for at least 24 hours to obtain C. 60 (OH) n .

[0015] To further specify, in step one, C 60 (OH) n The mass ratio of water to deionized water is 1:(1-5).

[0016] Further specifying, in step two, the mass ratio of silver nitrate to trisodium citrate is (1-3):2.

[0017] Further specifying, in step two, the mixture is stirred in a water bath at 40℃~80℃.

[0018] Further specifying, in step two, centrifugation at 8000 r / min to 10000 r / min shall be performed for at least 5 min.

[0019] Further specifying, in step two, vacuum drying at 50℃~80℃ for at least 24 hours.

[0020] Further specifying, in step three, C in the casting solution 60 (OH) n The content of -Ag complex is 0.2 wt.% to 1.0 wt.%, PVDF content is 8 wt.% to 12 wt.%, and PVP content is 0.5 wt.% to 2.0 wt.%.

[0021] Further specifying, in step three, stirring is carried out at 40℃~80℃ for 6h~12h.

[0022] To further specify, in step four, the scraper is adjusted to 50μm~250μm for film scraping.

[0023] This invention utilizes a tetrabutylammonium hydroxide (TBAH) alkaline catalytic method to convert C 60 Nanoparticles oxidized to hydrophilic C with multiple hydroxyl groups 60 (OH) n Then, using the in-situ growth method, Ag atoms are grown in situ on C. 60 (OH) n Above, we get C 60 (OH) n -Ag complex. The prepared C 60 (OH) n -Ag complexes have a particle size of around 100 nm, and elemental Ag is in the C... 60 (OH) n The dispersion is relatively uniform.

[0024] The preparation conditions of the PVDF ultrafiltration membrane of this invention are as follows: stirring temperature 60℃, stirring time 8h, substrate PVDF mass fraction 10%, pore-forming agent PVP mass fraction 1%. Under these conditions, the water flux of the PVDF ultrafiltration membrane is 224.11 L·m⁻¹. -2 ·h -1 The BSA rejection rate was 75%.

[0025] C 60 (OH) nWhen the addition amount of the -Ag complex is 0.6% of the substrate content, the water flux reaches as high as 804.05 L·m. -2 ·h -1 The retention rate of bovine serum albumin (BSA) also reached 96.44%. SEM characterization results showed that C... 60 (OH) n -Ag-modified PVDF ultrafiltration membranes have more surface pores than PVDF ultrafiltration membranes, and their internal structure changes from a "sponge-like" to a "finger-like" structure. EDS characterization results show that C 60 (OH) n The -Ag complex exhibits good compatibility with PVDF, and XRD characterization results confirm that C 60 (OH) n -Ag-modified PVDF ultrafiltration membrane contains C 60 (OH) n And Ag element.

[0026] PVDF ultrafiltration membrane, C 60 (OH) n Modified PVDF ultrafiltration membrane and C 60 (OH) n The average pore sizes of the Ag-modified PVDF ultrafiltration membranes were 54.91 nm, 40.52 nm, and 39.22 nm, respectively, and the average porosities were 68.50%, 79.53%, and 75.88%, respectively. PVDF ultrafiltration membranes, C 60 (OH) n Modified PVDF ultrafiltration membrane and C 60 (OH) n The Ag-modified PVDF ultrafiltration membranes exhibited water contact angles of 75.050°, 33.173°, and 34.504°, respectively; and tensile strengths of 6.00 N·mm. -2 4.82 N·mm -2 5.18 N·mm -2 After soaking in acidic solution for three weeks, the flux recovery rates were 48.04%, 66.33%, and 67.30%, respectively; after soaking in alkaline solution for three weeks, the flux recovery rates were 43.59%, 63.15%, and 67.22%, respectively. The inhibition zone diameters against *Escherichia coli* were 20±0.00 mm, 21±0.51 mm, and 23±0.35 mm, respectively; and the inhibition zone diameters against *Staphylococcus aureus* were 20±0.00 mm, 21±0.43 mm, and 23±0.45 mm, respectively. The Ra values ​​obtained by AFM were 34.5 nm, 26.4 nm, and 24.4 nm, respectively, and their electronegativity, from largest to smallest, was C. 60 (OH) n -Ag-modified PVDF ultrafiltration membrane, C 60 (OH) nThe modified PVDF ultrafiltration membrane and the PVDF ultrafiltration membrane had free resistance ratios (FRR) of 64.91%, 74.46%, and 79.08%, respectively. 60 (OH) n -Ag-modified PVDF ultrafiltration membranes are effective against aqueous solutions containing HA, FA, and BPA at concentrations of 5.0 mg·L⁻¹. -1 Under the specified conditions, the retention rates were 93.51%, 68.52%, and 93.37%, respectively. After the metal cations entered the solution to be separated, C... 60 (OH) n -Ag-modified PVDF ultrafiltration membranes showed a sharp decline in the retention rates of hydrophobic organic pollutants HA and BPA, while having a relatively small impact on the retention rate of FA.

[0027] This invention prepared C 60 (OH) n -Ag-modified PVDF ultrafiltration membrane. This membrane features high water flux, high retention capacity, high porosity, and uniform pore size distribution. It is a novel C-type membrane that integrates excellent properties such as good hydrophilicity, high tensile strength, good acid and alkali corrosion resistance, strong antibacterial effect, and excellent antifouling performance. 60 (OH) n -Ag-modified PVDF ultrafiltration membrane, which has a good effect on the treatment of wastewater containing organic pollutants and can be applied in the field of wastewater treatment.

[0028] To further understand the features and technical content of this invention, please refer to the following detailed description and accompanying drawings. However, the accompanying drawings are for reference and illustration only and are not intended to limit the invention. Attached Figure Description

[0029] Figure 1 It is C 60 (OH) n The effect of Ag content on water flux and rejection rate of PVDF ultrafiltration membrane;

[0030] Figure 2 It is C 60 (OH) n (a) Ag and C 60 (OH) n UV spectrum of the -Ag complex (b);

[0031] Figure 3 It is C 60 (OH) n (a) C 60 (OH) n Infrared spectrum of the -Ag complex (b);

[0032] Figure 4 It is C 60 (OH)n (a) C 60 (OH) n Raman spectrum of the -Ag complex (b);

[0033] Figure 5 It is C 60 (OH) n (a) C 60 (OH) n XRD pattern of the -Ag complex (b);

[0034] Figure 6 It is C 60 (OH) n (a) C 60 (OH) n -Particle size of the Ag complex (b);

[0035] Figure 7 It is C 60 (OH) n (a) C 60 (OH) n SEM of the -Ag complex (b);

[0036] Figure 8 It is C 60 (OH) n (a) C 60 (OH) n EDS plot of the -Ag complex (b);

[0037] Figure 9 It is C 60 (OH) n -SEM images of Ag-modified PVDF ultrafiltration membrane: (a) surface and (b) cross-section;

[0038] Figure 10 The contact angle of the ultrafiltration membrane (a) PVDF ultrafiltration membrane (b) C 60 (OH) n Modified PVDF ultrafiltration membrane (c)C 60 (OH) n -Ag-modified PVDF ultrafiltration membrane;

[0039] Figure 11 The antibacterial effect of ultrafiltration membrane on Escherichia coli (a) and Staphylococcus aureus (b) (1) PVDF ultrafiltration membrane (2) C 60 (OH) n Modified PVDF ultrafiltration membrane (3)C 60 (OH) n -Ag-modified PVDF ultrafiltration membrane;

[0040] Figure 12Two-dimensional and three-dimensional AFM images of different ultrafiltration membranes: (a) PVDF ultrafiltration membrane; (b) C 60 (OH) n Modified PVDF ultrafiltration membrane (c)C 60 (OH) n -Ag-modified PVDF ultrafiltration membrane;

[0041] Figure 13 The relationship between Zate potential and pH change of ultrafiltration membrane (a) PVDF ultrafiltration membrane (b) C 60 (OH) n Modified PVDF ultrafiltration membrane (c)C 60 (OH) n -Ag-modified PVDF ultrafiltration membrane;

[0042] Figure 14 It is C 60 (OH) n - Retention rate of FA, HA and BPA by Ag-modified PVDF ultrafiltration membrane;

[0043] Figure 15 It is C 60 (OH) n - Retention rate of FA salt solution by Ag-modified PVDF ultrafiltration membrane;

[0044] Figure 16 It is C 60 (OH) n - Retention rate of Ag-modified PVDF ultrafiltration membrane for HA aqueous solution;

[0045] Figure 17 It is C 60 (OH) n - Retention rate of BPA aqueous solution by Ag-modified PVDF ultrafiltration membrane. Detailed Implementation

[0046] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] Example 1: 1. A method for preparing a fullerol-silver modified PVDF ultrafiltration membrane, characterized in that the preparation method is achieved through the following steps:

[0048] Step 1: Add 20mg C 60 (OH) n Dissolve in 20 mL of deionized water and ultrasonically disperse until homogeneous to obtain C. 60 (OH) n Aqueous solution;

[0049] Step 2: Then add 8.5 mg of silver nitrate, stir for at least 10 minutes, then add 14.8 mg of trisodium citrate, stir in a 60°C water bath for 2 hours, centrifuge at 10000 rpm for 5 minutes, discard the supernatant, collect the precipitate, and vacuum dry at 50°C for 24 hours to obtain C. 60 (OH) n -Ag complex;

[0050] Step 3: Add a certain amount of C to DMF 60 (OH) n -Ag complex was sonicated to disperse it evenly, then PVDF and PVP were added, and the mixture was stirred at 60°C for 8 hours until a transparent and uniform casting solution was formed. The solution was then allowed to stand to remove bubbles.

[0051] The casting solution contains 1% PVP by mass and C 60 (OH) n The mass fraction of the -Ag complex is 0.6%, and the mass fraction of PVDF is 10%.

[0052] Step 4: Pour the degassed casting solution onto a glass plate, adjust the doctor blade to 200 μm for film scraping, and after the membrane is separated and formed, immerse it in a coagulation bath (distilled water). After the membrane is completely detached, soak it in distilled water for at least 24 hours to obtain C. 60 (OH) n -Ag-modified PVDF ultrafiltration membrane;

[0053] Among them, C mentioned in step one 60 (OH) n It is prepared through the following steps:

[0054] Step 1: Add 0.2gC 60 Mix with 100 mL of xylene and stir until the solution turns light purple. Then add 20 mL of 30% hydrogen peroxide and 4 mL of 10% tetrabutylammonium hydroxide. Bubbles will appear in the solution.

[0055] Step 2: In an oil bath at 80°C, under magnetic stirring, reflux the reaction for at least 16 hours. The solution will separate into layers. After cooling, collect the lower light brown solution.

[0056] Step 3: Stir in an ice bath, slowly add a 1:2 (v / v) mixture of n-hexane and isopropanol to the light brown solution. A brown precipitate will slowly crystallize out. Once no more crystals precipitate, continue stirring in an ice bath for 5 minutes, centrifuge at 10000 rpm for 5 minutes, discard the supernatant, and wash the precipitate at least three times with a 1:2 (v / v) mixture of n-hexane and isopropanol. Dry under vacuum at 50°C for 24 hours to obtain C. 60 (OH) n .

[0057] This embodiment uses the TBAH alkaline catalysis method to prepare C. 60 (OH) n C was then prepared via in-situ synthesis. 60 (OH) n -Ag complex. Further preparation of C 60 (OH) n -Ag-modified PVDF ultrafiltration membrane. This ultrafiltration membrane has high water flux, good BSA retention effect, dense surface skin with dense micropores, and internal structure composed of "sponge-like" and "finger-like" pores. It can separate organic macromolecular proteins with a precision of up to 35000 Da.

[0058] Comparative Example 1: DMF, PVDF and PVP were added to a round-bottom flask and stirred at 60°C for 8 hours until a transparent and homogeneous casting solution was formed. The solution was allowed to stand to remove bubbles. The degassed casting solution was poured onto a glass plate and the doctor blade was adjusted to 200 μm for membrane scraping. After the membrane was formed, it was immersed in a coagulation bath (distilled water). After the membrane was completely detached, it was soaked in distilled water for at least 24 hours to prepare a PVDF ultrafiltration membrane.

[0059] The casting solution of Comparative Example 1 contained 1% PVP and 10% PVDF by mass.

[0060] Comparative Example 2: A certain amount of C was added to the solvent DMF. 60 (OH) n The mixture was ultrasonically dispersed to ensure uniform dispersion. PVDF and PVP were then added to a round-bottom flask and stirred at 60°C for 8 hours until a transparent, homogeneous casting solution was formed. The solution was then allowed to stand to remove bubbles. The degassed casting solution was poured onto a glass plate, and a doctor blade adjusted to 200 μm was used for film scraping. After the membrane was separated and formed, it was immersed in a coagulation bath (distilled water). Once the membrane was completely detached, it was soaked in distilled water for at least 24 hours to prepare C. 60 (OH) n Modified PVDF ultrafiltration membrane.

[0061] The casting solution of Comparative Example 2 contained 1% PVP by mass, C 60 (OH) n The mass fraction is 0.6%, and the PVDF mass fraction is 10%.

[0062] Table 1. Inhibition diameters of ultrafiltration membranes against Escherichia coli and Staphylococcus aureus

[0063]

[0064] Table 1 shows that PVDF ultrafiltration membrane, C 60 (OH) n Modified PVDF ultrafiltration membrane, C 60 (OH) nThe Ag-modified PVDF ultrafiltration membranes showed inhibition zone diameters of 20±0.00 mm, 21±0.51 mm, and 23±0.35 mm against *Escherichia coli*, and 20±0.00 mm, 21±0.43 mm, and 23±0.45 mm against *Staphylococcus aureus*. As shown in Table 2, the PVDF ultrafiltration membranes had no inhibitory effect on either bacterium, because the PVDF polymer material itself has no antibacterial properties. 60 (OH) n Modified PVDF ultrafiltration membrane, C 60 (OH) n -Ag-modified PVDF ultrafiltration showed some inhibitory effect on both, and the latter's antibacterial effect was significantly higher than the former. This is because C 60 (OH) n The antibacterial properties of the modified PVDF ultrafiltration membrane originate from C 60 (OH) n C 60 (OH) n The antibacterial properties of Ag-modified PVDF ultrafiltration membranes are derived from C. 60 (OH) n It has a dual effect with Ag. Studies have shown...

[84] C 60 Under photoexcitation, it can activate oxygen and generate superoxide anion free radicals by producing singlet oxygen, which participate in the inactivation of bacteria; silver has excellent antibacterial effect, and by contacting microbial cells, it destroys the cell structure and achieves the bactericidal effect.

[0065] Table 2 Irreversible flux loss rate and reversible flux recovery rate of different ultrafiltration membranes

[0066]

[0067] The optimal preparation conditions for the PVDF ultrafiltration membrane using the immersion precipitation phase inversion method are: stirring temperature 60℃, stirring time 8h, substrate PVDF mass fraction 10%, and pore-forming agent PVP mass fraction 1%. Under these conditions, the water flux of the PVDF ultrafiltration membrane is 224.11 L·m⁻¹. -2 ·h -1 The BSA rejection rate was 75.68%. When C 60 (OH) n When the amount of the -Ag complex added is 0.6wt%, C 60 (OH) n The Ag-modified PVDF ultrafiltration membrane has a water flux of 804.05 L·m⁻¹. -2 ·h -1 The BSA rejection rate was 96.44%. 60 (OH) n-Ag-modified PVDF ultrafiltration membranes have a dense microporous structure on their surface, with an average micropore diameter of 75.88 nm. The membrane interior consists of a "sponge-like" structure and a finger-like pore structure. Figure 9 b).

[0068] C 60 (OH) n -The water contact angle of the Ag-modified PVDF ultrafiltration membrane is 34.504°. Figure 10 The tensile strength is 5.18 N·mm. -2 C 60 (OH) n - The flux recovery rate of Ag-modified PVDF ultrafiltration membrane was 67.30% after soaking in acid solution for 3 weeks and 67.22% after soaking in alkaline solution for 3 weeks; C 60 (OH) n The Ag-modified PVDF ultrafiltration membrane exhibited inhibition zone diameters of 23±0.35 mm and 23±0.45 mm against Escherichia coli and Staphylococcus aureus, respectively. The modified PVDF ultrafiltration membrane had a roughness Ra of 24.4 nm, a negative Zeta potential, and a reversible flux recovery (FRR) of 79.08%.

[0069] C 60 (OH) n The Ag-modified PVDF ultrafiltration membrane has a retention precision of 35000 Da for large organic protein molecules, and a retention concentration of 5.0 mg·L⁻¹ for hydrophilic organic macromolecular compound FA aqueous solution, hydrophobic organic macromolecular compound HA aqueous solution, and hydrophobic small organic molecule compound BPA aqueous solution. -1 Under the given conditions, the retention rates were 93.51%, 68.52%, and 93.37%, respectively; after adding NaCl, MgCl2, and CaCl2 solutions to FA, HA, and BPA aqueous solutions, respectively, C 60 (OH) n -Ag-modified PVDF ultrafiltration membranes showed a decreasing trend in the rejection rates of different salt solutions of FA, HA, and BPA. Moreover, the decrease in rejection rates for different salt solutions of HA and BPA was greater than that for different salt solutions of BPA.

[0070] This invention produces C, which combines excellent hydrophilicity, high tensile strength, good acid and alkali corrosion resistance, strong antibacterial effect, and good anti-fouling properties. 60 (OH) n -Ag-modified PVDF ultrafiltration membrane. C 60 (OH) n -Ag-modified PVDF ultrafiltration membranes can be applied in the field of wastewater treatment.

Claims

1. A method for preparing a fullerol-silver modified PVDF ultrafiltration membrane, characterized in that, The preparation method is achieved through the following steps: Step 1: Place C 60 (OH) n Dissolved in deionized water and ultrasonically dispersed until homogeneous, yielding C 60 (OH) n Aqueous solution; Step 2: Then add silver nitrate and stir for at least 10 minutes. Next, add trisodium citrate and stir in a water bath for at least 2 hours. Centrifuge, discard the supernatant, collect the precipitate, and vacuum dry to obtain C. 60 (OH) n -Ag complex; Step 3: Add a certain amount of C to DMF 60 (OH) n -Ag complex, sonicated to disperse it evenly, then PVDF and PVP are added, stirred at a certain temperature for a certain time until a transparent and uniform casting solution is formed, and then allowed to stand to remove bubbles; Step 4: Pour the degassed casting solution onto a glass plate, scrape the film with a doctor blade, and after the film is separated and formed, immerse it in a coagulation bath. After the film is completely detached, soak it in distilled water for at least 24 hours to obtain C. 60 (OH) n -Ag-modified PVDF ultrafiltration membrane.

2. The preparation method according to claim 1, characterized in that, Step 1, C 60 (OH) n It is prepared through the following steps: Step 1: Add 0.1g to 0.5g of C 60 Mix with 50mL to 250mL of xylene and stir until the solution turns light purple. Then add 10mL to 50mL of 30% hydrogen peroxide and 10mL to 50mL of 10% tetrabutylammonium hydroxide. Bubbles will appear in the solution. Step 2: In an oil bath at 60℃~100℃, under magnetic stirring, reflux the reaction for at least 16 hours. The solution will separate into layers. After cooling, collect the lower light brown solution. Step 3: Stir in an ice bath, slowly add a mixture of n-hexane and isopropanol in a volume ratio of (1-3):2 to the light brown solution. A brown precipitate will slowly crystallize out. After no more crystals precipitate out, continue stirring in an ice bath for at least 5 minutes. Centrifuge at 8000-10000 rpm for at least 5 minutes. Discard the supernatant, and wash the precipitate at least 3 times with a mixture of n-hexane and isopropanol in a volume ratio of (1-3):

2. Dry under vacuum at 50-80°C for at least 24 hours to obtain C. 60 (OH) n .

3. The preparation method according to claim 1, characterized in that, In step one, C 60 (OH) n The mass ratio of water to deionized water is 1:(1-5).

4. The preparation method according to claim 3, characterized in that, In step two, the mass ratio of silver nitrate to trisodium citrate is (1-3):

2.

5. The preparation method according to claim 1, characterized in that, In step two, the mixture is stirred in a water bath at 40℃~80℃.

6. The preparation method according to claim 1, characterized in that, In step two, centrifuge at 8000 r / min to 10000 r / min for at least 5 min.

7. The preparation method according to claim 1, characterized in that, In step two, vacuum drying at 50℃~80℃ shall be carried out for at least 24 hours.

8. The preparation method according to claim 1, characterized in that, In step three, C in the casting solution 60 (OH) n The content of -Ag complex is 0.2wt% to 1.0wt%, PVDF content is 8wt% to 12wt%, and PVP content is 0.5wt% to 2.0wt%.

9. The preparation method according to claim 1, characterized in that, In step three, stir at 40℃~80℃ for 6h~12h.

10. The preparation method according to claim 1, characterized in that, In step four, the scraper is adjusted to 50μm~250μm for film scraping.

Images