A nano-composite forward osmosis membrane with antibacterial effect and a preparation method and application thereof

Abstract

The application provides a nano-composite forward osmosis membrane with an antibacterial effect and a preparation method and application thereof, wherein the preparation method comprises the following steps: preparing a homogeneous dispersion liquid formed by Mxene two-dimensional nanosheet and organic nanoparticle dispersion liquid; uniformly filtering the homogeneous dispersion liquid on the surface of a substrate through vacuum filtration to form a porous nanolaminate membrane; and then performing interfacial polymerization reaction of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) on the surface of the porous nanolaminate membrane to form a dense selective separation layer. The nano-composite forward osmosis membrane prepared by the application has excellent water permeability and high salt rejection rate, and can maintain stable water flux performance in long-time operation test; and has certain application potential in seawater desalination and organic solvent separation and the like. Meanwhile, in the antibacterial experiment, the activity antibacterial test of the porous nanolaminate composite forward osmosis membrane on escherichia coli reaches almost 100%.

Description

Technical Field

[0001] This invention relates to the field of forward osmosis membrane technology, and in particular to a nanocomposite forward osmosis membrane with antibacterial effect, its preparation method and application. Technical Background

[0002] The rapid development of the global economy and the continuous growth of the population have accelerated the consumption of water resources. Therefore, the rational and effective allocation of existing water resources and the development of water purification technologies with low energy consumption are particularly important. Large quantities of industrial wastewater often contain numerous microorganisms, including bacteria, viruses, and fungi. Some pathogenic microorganisms, after entering water bodies, can multiply rapidly under suitable conditions, causing eutrophication and even carrying infectious diseases that can spread to humans through the food chain, leading to disease outbreaks. Forward osmosis membrane separation technology has become a widely studied water treatment technology due to its low energy consumption and ease of installation and operation. Furthermore, the powerful separation, retention, and concentration capabilities of forward osmosis membrane separation technology make it a promising application in seawater desalination and organic solvent separation.

[0003] A forward osmosis membrane consists of two parts: a dense upper skin layer and a porous lower support layer. The separation performance of a forward osmosis membrane is primarily determined by the skin layer structure on its surface. However, in practical applications, complex aquatic environments contain not only large amounts of organic and inorganic pollutants, but also significant membrane fouling caused by microorganisms. Existing forward osmosis membranes are unstable in complex aquatic environments, and their surfaces are easily fouled, leading to a rapid decline in water flux.

[0004] Existing technologies still need improvement and development. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a nanocomposite forward osmosis membrane with antibacterial effect, its preparation method and application, in order to solve the problems of poor antibacterial effect of existing forward osmosis membranes, unstable operation in complex water bodies, and rapid decline in water flux due to easy fouling of the membrane surface.

[0006] The technical solution of the present invention is as follows:

[0007] A method for preparing a nanocomposite forward osmosis membrane with antibacterial effect, comprising the following steps:

[0008] Hydrofluoric acid solution was added to titanium aluminum carbon for etching, and after acid washing to neutrality, ultrasonic dispersion was performed to obtain Mxene two-dimensional nanosheets.

[0009] Tannic acid and heme C were dispersed in an aqueous phase to obtain an organic nanoparticle dispersion.

[0010] The Mxene two-dimensional nanosheets were mixed with the organic nanoparticle dispersion to obtain a homogeneous dispersion.

[0011] The homogeneous dispersion was dropleted onto the substrate surface and subjected to vacuum filtration to form a porous nano-layer membrane on the substrate surface.

[0012] An MPD aqueous solution is added to the surface of the porous nano-sandwich membrane. After a first predetermined time, excess MPD aqueous solution is removed from the surface of the porous nano-sandwich membrane to obtain an aqueous-treated porous nano-sandwich membrane.

[0013] Next, a TMC oil phase solution is added to the surface of the aqueous-treated porous nano-sandwich membrane. After a second predetermined time, excess TMC oil phase solution is removed from the surface of the porous nano-sandwich membrane to obtain an oil-treated porous nano-sandwich membrane.

[0014] The oil-phase treated porous nano-layer membrane was dried to obtain a nanocomposite forward osmosis membrane with antibacterial effect.

[0015] The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect, wherein the substrate is one of PES substrate, Psf substrate, PVDF substrate and PAN substrate.

[0016] The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect, wherein the first predetermined time is 1-5 min; and the second predetermined time is 30 s-2 min.

[0017] The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect, wherein the concentration of the MPD aqueous solution is 3-5 wt%.

[0018] The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect, wherein the concentration of the TMC oil phase solution is 0.1-0.2 wt%.

[0019] The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect, wherein in the step of drying the oil-phase treated porous nano-layer membrane, the drying temperature is 50-70℃ and the time is 4-8min.

[0020] A nanocomposite forward osmosis membrane with antibacterial effect is prepared by the method for preparing a nanocomposite forward osmosis membrane with antibacterial effect as described in this invention.

[0021] An application of a nanocomposite forward osmosis membrane with antibacterial effect, wherein the nanocomposite forward osmosis membrane with antibacterial effect is used for organic solvent separation.

[0022] Beneficial effects: The nanocomposite forward osmosis membrane prepared by this invention exhibits excellent water permeability and high salt rejection rate, maintaining stable water flux performance during long-term operation testing; it shows certain application potential in seawater desalination and organic solvent separation. Furthermore, in antibacterial experiments, the porous nano-layered composite forward osmosis membrane achieved almost 100% antibacterial activity against Escherichia coli. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the preparation method of a nanocomposite forward osmosis membrane with antibacterial effect according to the present invention.

[0024] Figure 2 This is a schematic diagram illustrating the preparation principle of the porous nano-layer membrane in this invention.

[0025] Figure 3 The schematic diagram of the present invention for preparing a nanocomposite forward osmosis membrane on a PES membrane.

[0026] Figure 4 The graphs show the water flux, reverse salt flux, and selective separation coefficient data for AL-DS and AL-FS modes. PES / PA is the control membrane, and CTM-2 / 4 / 6 / 8 / 10 / PA represent different amounts of inorganic-organic nanoparticles. The extractant is 1M NaCl.

[0027] Figure 5 The graphs show the water flux, reverse salt flux, and selective separation coefficient under different NaCl concentrations and seawater as the draw solution conditions in AL-DS and AL-FS modes. PES / PA is the control membrane, and CTM-8 / PA is the optimal membrane.

[0028] Figure 6 The graph shows the water flux, reverse salt flux, and selective separation coefficient of the optimal CTM-8 / PA membrane under AL-DS and AL-FS modes. 1M NaCl was used as the draw solution, and the running time was 72h.

[0029] Figure 7 The graph shows the ethanol flux and selective separation coefficient of the optimal CTM-8 / PA membrane under AL-DS and AL-FS modes. 2M LiCl was used as the draw solution and 0.01mM methyl orange-ethanol was used as the feed.

[0030] Figure 8 The graph shows the retention data of methyl orange dye by the optimal CTM-8 / PA membrane under both AL-DS and AL-FS modes.

[0031] Figure 9 The graph shows the inhibition rate of CTM-8 / PA membrane against Escherichia coli compared to the control membrane.

[0032] Figure 10Comparison of plate count images of Escherichia coli using the optimal CTM-8 / PA membrane and the control membrane. Detailed Implementation

[0033] This invention provides a nanocomposite forward osmosis membrane with antibacterial effect, its preparation method, and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0034] Please see Figure 1 , Figure 1 The present invention provides a method for preparing a nanocomposite forward osmosis membrane with antibacterial effect, as shown in the figure, which includes the following steps:

[0035] S10. Add hydrofluoric acid solution to titanium aluminum carbon for etching treatment, acid wash until neutral, and then perform ultrasonic dispersion treatment to obtain Mxene two-dimensional nanosheets.

[0036] S20. Tannic acid and heme C are dispersed in an aqueous phase to obtain an organic nanoparticle dispersion.

[0037] S30. Mix the Mxene two-dimensional nanosheets with the organic nanoparticle dispersion to obtain a homogeneous dispersion;

[0038] S40. The homogeneous dispersion liquid is added to the substrate surface and vacuum filtered to form a porous nano-layer membrane on the substrate surface.

[0039] S50. Add an MPD aqueous solution to the surface of the porous nano-sandwich membrane, and remove excess MPD aqueous solution from the surface of the porous nano-sandwich membrane after a first predetermined time to obtain an aqueous-treated porous nano-sandwich membrane.

[0040] S60. Next, a TMC oil phase solution is added to the surface of the aqueous-treated porous nano-sandwich membrane. After a second predetermined time, excess TMC oil phase solution is removed from the surface of the porous nano-sandwich membrane to obtain an oil-treated porous nano-sandwich membrane.

[0041] S70. After drying the oil-phase treated porous nano-layer membrane, a nano-composite forward osmosis membrane with antibacterial effect is obtained.

[0042] Specifically, such as Figure 2 and Figure 3As shown, this invention first uses hydrofluoric acid to etch MAX (Ti3AlC2, titanium aluminum carbon) to prepare Mxene two-dimensional nanosheets. The Mxene two-dimensional nanosheets are two-dimensional transition metal carbides. Hydrofluoric acid can extract weakly bound A-site elements (such as Al atoms) from the MAX phase, resulting in Mxene two-dimensional nanosheets with high specific surface area and high electrical conductivity. Then, tannic acid and heme C are dispersed in an aqueous phase to obtain an organic nanoparticle dispersion, which is a protein-polyphenol nanoparticle dispersion. Next, the Mxene two-dimensional nanosheets are mixed with the protein-polyphenol nanoparticle dispersion to obtain a homogeneous CYC+TA@Mxene dispersion. This homogeneous dispersion is then dropwise added to the surface of a porous polyethersulfone (PES) substrate and subjected to vacuum filtration, allowing the rigid Mxene two-dimensional nanosheets to embed into the flexible organic nanoparticles, forming a porous nanolayer membrane (such as...). Figure 2 As shown), this porous nano-layered membrane contains nanoporous water channels, ensuring enhanced water permeability of the nanocomposite forward osmosis membrane. Finally, an interfacial polymerization reaction of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) is performed on the surface of the porous nano-layered membrane to form a unique wrinkled spherical polyamide active selective layer (e.g., as shown). Then, an aqueous solution of MPD and an oil-phase solution of TMC are added to the porous nano-layered membrane, and an interfacial polymerization reaction occurs on the surface of the porous nano-layered membrane to form a unique wrinkled spherical polyamide active selective layer. Figure 3 As shown in the figure, the nanocomposite forward osmosis membrane with antibacterial effect was finally obtained. The nanocomposite forward osmosis membrane prepared by this invention has excellent water permeability and high salt rejection rate, and maintains stable water flux performance during long-term operation testing; it shows certain application potential in seawater desalination and organic solvent separation. Meanwhile, in the antibacterial experiment, the porous nano-layered composite forward osmosis membrane achieved almost 100% antibacterial activity against Escherichia coli.

[0043] In some embodiments, the substrate is one of a PES substrate, a PSF substrate, a PVDF substrate, and a PAN substrate, but is not limited thereto.

[0044] In some implementations, the first predetermined time is 1-5 min, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, etc.; the second predetermined time is 30 s-2 min, for example, it can be 30 s, 1 min, 2 min, etc.

[0045] In some embodiments, the concentration of the MPD aqueous solution is 3-5 wt%, for example, the concentration of the MPD aqueous solution is 4 wt%.

[0046] In some embodiments, the concentration of the TMC oil phase solution is 0.1-0.2 wt%, for example, the concentration of the TMC oil phase solution is 0.15 wt%.

[0047] In some embodiments, the drying process of the oil-phase treated porous nanolayer membrane is carried out at a temperature of 50-70°C for 4-8 minutes. For example, the drying temperature is 60°C for 5 minutes.

[0048] In some embodiments, a nanocomposite forward osmosis membrane with antibacterial effect is also provided, wherein it is prepared by the method for preparing the nanocomposite forward osmosis membrane with antibacterial effect described in this invention.

[0049] In some embodiments, an application of a nanocomposite forward osmosis membrane with antibacterial effect is also provided, wherein the nanocomposite forward osmosis membrane with antibacterial effect is used for organic solvent separation.

[0050] The preparation method and performance of the antibacterial nanocomposite forward osmosis membrane of the present invention will be further explained below through specific embodiments:

[0051] Example 1

[0052] 2g of MAX phase (Ti3AlC2) was placed in a polytetrafluoroethylene container, and 20ml of HF solution was added for etching for 48h. The mixture was then acid-washed until neutral, and finally ultrasonically dispersed to obtain Mxene two-dimensional nanosheets. 50mg of tannic acid (TA) and 50mg of heme C (CYC) were dispersed in the aqueous phase to obtain an organic nanoparticle dispersion. A certain concentration of Mxene two-dimensional nanosheets and the organic particle dispersion were placed in a beaker and stirred for 48h to obtain a homogeneous CYC+TA@Mxene dispersion.

[0053] The PES substrate was immersed in an ethanol solution for 5 minutes, then removed and placed in a vacuum filtration apparatus. 2 ml of a homogeneous dispersion of CYC+TA@Mxene was placed on the substrate surface using a pipette. After removing excess aqueous phase by vacuum filtration, a porous nanolayer structure was formed on the membrane surface.

[0054] A certain amount of MPD solid was dissolved in an aqueous phase to obtain a 4 wt% MPD aqueous solution, and a certain amount of TMC solid was dissolved in an n-Hexane oil phase to obtain a 0.15 wt% TMC oil solution. After the porous nano-sandwich membrane was dried, a certain amount of MPD aqueous phase was first added to the membrane surface, and after 2 minutes, the excess aqueous solution was removed. Then, a certain amount of TMC oil phase was added, and after 1 minute, the excess solution was poured off. The membrane was then placed in a 60℃ oven and dried for 5 minutes to obtain a porous nano-sandwich composite forward osmosis membrane.

[0055] Example 2

[0056] 2g of MAX phase (Ti3AlC2) was placed in a polytetrafluoroethylene container, and 20ml of HF solution was added for etching for 48h. The mixture was then acid-washed until neutral, and finally ultrasonically dispersed to obtain Mxene two-dimensional nanosheets. 50mg of tannic acid (TA) and 50mg of heme C (CYC) were dispersed in the aqueous phase to obtain an organic nanoparticle dispersion. A certain concentration of Mxene two-dimensional nanosheets and the organic particle dispersion were placed in a beaker and stirred for 48h to obtain a homogeneous CYC+TA@Mxene dispersion.

[0057] The PES substrate was immersed in an ethanol solution for 5 minutes, then removed and placed in a vacuum filtration apparatus. 4 ml of a homogeneous dispersion of CYC+TA@Mxene was placed on the substrate surface using a pipette. After removing excess aqueous phase by vacuum filtration, a porous nanolayer structure was formed on the membrane surface.

[0058] A certain amount of MPD solid was dissolved in an aqueous phase to obtain a 4 wt% MPD aqueous solution, and a certain amount of TMC solid was dissolved in an n-Hexane oil phase to obtain a 0.15 wt% TMC oil solution. After the porous nano-sandwich membrane was dried, a certain amount of MPD aqueous phase was first added to the membrane surface, and after 2 minutes, the excess aqueous solution was removed. Then, a certain amount of TMC oil phase was added, and after 1 minute, the excess solution was poured off. The membrane was then placed in a 60℃ oven and dried for 5 minutes to obtain a porous nano-sandwich composite forward osmosis membrane.

[0059] Example 3

[0060] 2g of MAX phase (Ti3AlC2) was placed in a polytetrafluoroethylene container, and 20ml of HF solution was added for etching for 48h. The mixture was then acid-washed until neutral, and finally ultrasonically dispersed to obtain Mxene two-dimensional nanosheets. 50mg of tannic acid (TA) and 50mg of heme C (CYC) were dispersed in the aqueous phase to obtain an organic nanoparticle dispersion. A certain concentration of Mxene two-dimensional nanosheets and the organic particle dispersion were placed in a beaker and stirred for 48h to obtain a homogeneous CYC+TA@Mxene dispersion.

[0061] The PES substrate was immersed in an ethanol solution for 5 minutes, then removed and placed in a vacuum filtration apparatus. 6 ml of a homogeneous dispersion of CYC+TA@Mxene was placed on the substrate surface using a pipette. After removing excess aqueous phase by vacuum filtration, a porous nanolayer structure was formed on the membrane surface.

[0062] A certain amount of MPD solid was dissolved in an aqueous phase to obtain a 4 wt% MPD aqueous solution, and a certain amount of TMC solid was dissolved in an n-Hexane oil phase to obtain a 0.15 wt% TMC oil solution. After the porous nano-sandwich membrane was dried, a certain amount of MPD aqueous phase was first added to the membrane surface, and after 2 minutes, the excess aqueous solution was removed. Then, a certain amount of TMC oil phase was added, and after 1 minute, the excess solution was poured off. The membrane was then placed in a 60℃ oven and dried for 5 minutes to obtain a porous nano-sandwich composite forward osmosis membrane.

[0063] Example 5

[0064] 2g of MAX phase (Ti3AlC2) was placed in a polytetrafluoroethylene container, and 20ml of HF solution was added for etching for 48h. The mixture was then acid-washed until neutral, and finally ultrasonically dispersed to obtain Mxene two-dimensional nanosheets. 50mg of tannic acid (TA) and 50mg of heme C (CYC) were dispersed in the aqueous phase to obtain an organic nanoparticle dispersion. A certain concentration of Mxene two-dimensional nanosheets and the organic particle dispersion were placed in a beaker and stirred for 48h to obtain a homogeneous CYC+TA@Mxene dispersion.

[0065] The PES substrate was immersed in an ethanol solution for 5 minutes, then removed and placed in a vacuum filtration apparatus. 8 ml of a homogeneous dispersion of CYC+TA@Mxene was placed on the substrate surface using a pipette. After removing excess aqueous phase by vacuum filtration, a porous nanolayer structure was formed on the membrane surface.

[0066] A certain amount of MPD solid was dissolved in an aqueous phase to obtain a 4 wt% MPD aqueous solution, and a certain amount of TMC solid was dissolved in an n-Hexane oil phase to obtain a 0.15 wt% TMC oil solution. After the porous nano-sandwich membrane was dried, a certain amount of MPD aqueous phase was first added to the membrane surface, and after 2 minutes, the excess aqueous solution was removed. Then, a certain amount of TMC oil phase was added, and after 1 minute, the excess solution was poured off. The membrane was then placed in a 60℃ oven and dried for 5 minutes to obtain a porous nano-sandwich composite forward osmosis membrane.

[0067] Example 6

[0068] 2g of MAX phase (Ti3AlC2) was placed in a polytetrafluoroethylene container, and 20ml of HF solution was added for etching for 48h. The mixture was then acid-washed until neutral, and finally ultrasonically dispersed to obtain Mxene two-dimensional nanosheets. 50mg of tannic acid (TA) and 50mg of heme C (CYC) were dispersed in the aqueous phase to obtain an organic nanoparticle dispersion. A certain concentration of Mxene two-dimensional nanosheets and the organic particle dispersion were placed in a beaker and stirred for 48h to obtain a homogeneous CYC+TA@Mxene dispersion.

[0069] The PES substrate was immersed in an ethanol solution for 5 minutes, then removed and placed in a vacuum filtration apparatus. 10 ml of the homogeneous dispersion of CYC+TA@Mxene was placed on the substrate surface using a pipette. After the vacuum pump was turned on to remove excess aqueous phase, a porous nanolayer structure was formed on the membrane surface.

[0070] A certain amount of MPD solid was dissolved in an aqueous phase to obtain a 4 wt% MPD aqueous solution, and a certain amount of TMC solid was dissolved in an n-Hexane oil phase to obtain a 0.15 wt% TMC oil solution. After the porous nano-sandwich membrane was dried, a certain amount of MPD aqueous phase was first added to the membrane surface, and after 2 minutes, the excess aqueous solution was removed. Then, a certain amount of TMC oil phase was added, and after 1 minute, the excess solution was poured off. The membrane was then placed in a 60℃ oven and dried for 5 minutes to obtain a porous nano-sandwich composite forward osmosis membrane.

[0071] Comparative Example 1

[0072] A forward osmosis membrane, denoted as PES / PA, is prepared by directly performing interfacial polymerization of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) on the surface of the original PES membrane.

[0073] The forward osmosis membranes prepared in Examples 1-6 and Comparative Example 1 were tested for water flux, reverse salt flux, and selective separation coefficient in both AL-DS and AL-FS modes.

[0074] Using 1M NaCl as the extraction solution and deionized water as the feed solution,

[0075]

[0076] The water flux (J) of the forward osmosis membrane in Examples 1-6 and Comparative Example 1 was calculated according to equation (1). w L / m 2 / h (abbreviated as LMH), reverse salt flux and selective separation coefficient, results are as follows Figure 4 As shown, from Figure 4 It can be seen that the modified membrane outperforms the original PES / PA membrane in both modes in terms of water flux, reverse salt flux, and selective separation coefficient. In particular, the CTM-8 / PA membrane achieves the best results when the amount of CYC+TA@Mxene reaches 8 ml.

[0077] Furthermore, under both AL-DS and AL-FS modes, the water flux, reverse salt flux, and selective separation coefficient of the optimal CTM-8 / PA membrane and the forward osmosis membrane in Comparative Example 1 were calculated under different NaCl concentrations and seawater as the draw solution. The results are as follows: Figure 5 As shown, from Figure 5It can be seen that with the increase of the extract concentration, the water flux and reverse salt flux of both PES / PA and CTM-8 / PA membranes are enhanced. However, the CTM-8 / PA membrane is significantly better than PES / PA, with the water flux increasing to about 2.4 times that of the original membrane, while the selective separation coefficient is significantly lower than that of PES / PA.

[0078] Next, the water flux, reverse salt flux, and selective separation coefficient of the optimal CTM-8 / PA membrane were calculated under both AL-DS and AL-FS modes, with 1M NaCl as the draw solution and a running time of 72 h; the results are as follows. Figure 6 As shown, from Figure 6 It can be seen that during long-term operation, the data on water flux, reverse salt flux, and selective separation coefficient of the CTM-8 / PA membrane indicate that the modified membrane has a relatively stable operating capability. Although the water flux decreases slightly, the overall performance remains stable.

[0079] Next, in both AL-DS and AL-FS modes, using 2M LiCl as the extractant and 0.01mM methyl orange-ethanol as the feedstock, the ethanol flux and selective separation coefficient of the optimal CTM-8 / PA membrane were calculated. The results are as follows: Figure 7 As shown, from Figure 7 It can be seen that the ethanol flux of the CTM-8 / PA membrane can reach 9 LMH and 5.1 LMH, respectively, and the selective separation coefficients are 0.44 gMH and 0.4 gMH in AL-DS and AL-FS modes, respectively.

[0080] Furthermore, the retention data of the optimal CTM-8 / PA membrane for methyl orange dye were calculated under both AL-DS and AL-FS modes, and the results are as follows: Figure 8 As shown, from Figure 8 As can be seen, the CTM-8 / PA membrane exhibits methyl orange rejection rates of 98.9% and 99.7% in AL-DS and AL-FS modes, respectively.

[0081] Finally, the forward osmosis membranes prepared in Example 1 and Comparative Example 1 were subjected to antibacterial tests: the samples were placed in 24-well plates with corresponding labels, and Escherichia coli was diluted to 10 μL with LB liquid medium. 5 CFU / mL. Take 20 μL of bacterial suspension and add it to the surface of the corresponding numbered sample, place it in a constant temperature incubator at 37℃, and incubate for 2 hours.

[0082] After culturing, rinse the sample surface with 2 mL of sterile PBS, and then perform a 10-fold serial dilution of the rinsed bacterial solution (this test uses 10...). 0 10 1 10 2Three dilution factors were used, and 100 μL of each dilution was evenly spread onto LB solid medium. The medium was incubated at 37°C for 18 hours, then photographed and the colony count was recorded.

[0083] The results are as follows Figure 9 and Figure 10 As shown in the figure, under the same test conditions, the nanocomposite forward osmosis membrane with antibacterial effect in Example 1 has an activity inhibition rate of almost 100% against Escherichia coli, while the forward osmosis membrane in Comparative Example 1 does not have obvious antibacterial properties.

[0084] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a nanocomposite forward osmosis membrane with antibacterial effect, characterized in that, Including the following steps: Hydrofluoric acid solution was added to titanium aluminum carbon for etching, and after acid washing to neutrality, ultrasonic dispersion was performed to obtain Mxene two-dimensional nanosheets. Tannic acid and heme C were dispersed in an aqueous phase to obtain an organic nanoparticle dispersion. The Mxene two-dimensional nanosheets were mixed with the organic nanoparticle dispersion to obtain a homogeneous dispersion. The homogeneous dispersion liquid droplets are added to the substrate surface and vacuum filtered to embed the Mxene two-dimensional nanosheets into flexible organic nanoparticles, forming a porous nano-layer membrane on the substrate surface. An MPD aqueous solution is added to the surface of the porous nano-sandwich membrane. After a first predetermined time, excess MPD aqueous solution is removed from the surface of the porous nano-sandwich membrane to obtain an aqueous-treated porous nano-sandwich membrane. Next, a TMC oil phase solution is added to the surface of the aqueous-treated porous nano sandwich membrane. After a second predetermined time, excess TMC oil phase solution is removed from the surface of the porous nano sandwich membrane, so that MPD and TMC undergo interfacial polymerization reaction on the surface of the porous nano sandwich membrane to obtain an oil-treated porous nano sandwich membrane. The surface of the oil-treated porous nano-sandwich membrane is a polyamide active selective layer with a wrinkled spherical structure. The oil-phase treated porous nano-layer membrane was dried to obtain a nano-composite forward osmosis membrane with antibacterial effect. The second predetermined time is 30 seconds to 2 minutes.

2. The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect according to claim 1, characterized in that, The substrate is one of PES substrate, Psf substrate, PVDF substrate and PAN substrate.

3. The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect according to claim 1, characterized in that, The first predetermined time is 1-5 minutes.

4. The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect according to claim 1, characterized in that, The concentration of the MPD aqueous solution is 3-5 wt%.

5. The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect according to claim 1, characterized in that, The concentration of the TMC oil phase solution is 0.1-0.2 wt%.

6. The method for preparing the nanocomposite forward osmosis membrane with antibacterial effect according to claim 1, characterized in that, In the step of drying the oil-phase treated porous nano-layer membrane, the drying temperature is 50-70℃ and the time is 4-8 minutes.

7. A nanocomposite forward osmosis membrane with antibacterial effect, characterized in that, The nanocomposite forward osmosis membrane with antibacterial effect as described in any one of claims 1-6 is prepared.

8. An application of the nanocomposite forward osmosis membrane with antibacterial effect as described in claim 7, characterized in that, The nanocomposite forward osmosis membrane with antibacterial effect is used for organic solvent separation.

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