Inorganic atomic layer reinforced high-temperature-resistant nanofiltration membrane as well as preparation method and application thereof

Abstract

The invention discloses an inorganic atomic layer reinforced high-temperature-resistant nanofiltration membrane and a preparation method and application thereof, and belongs to the technical field of water treatment.The preparation method comprises the steps that firstly, a polymer porous basement membrane is modified through an atomic layer deposition technology, an inorganic atomic layer is introduced to the porous basement membrane, and the modified porous basement membrane is prepared; and performing interfacial polymerization reaction on a water-phase solution containing an amine monomer and a surfactant and an oil-phase solution containing a multi-acyl chloride monomer on the modified porous substrate membrane, and curing and cross-linking to prepare the inorganic atomic layer reinforced high-temperature-resistant nanofiltration membrane. According to the method, the thickness of the inorganic atomic layer can be accurately controlled, the mechanical strength and thermal stability of the porous basement membrane are improved, and the product high-temperature-resistant nanofiltration membrane has excellent high-temperature nanofiltration performance, water flux and long-term stability and is suitable for water treatment, ion screening and the like in a high-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly relates to a high-temperature resistant nanofiltration membrane enhanced by inorganic atomic layers, a preparation method thereof, and an application thereof. Background Art

[0002] Water treatment and water resource reuse are important means to solve the problems of water resource shortage and water pollution. As an efficient separation membrane, the structure of the nanofiltration membrane includes a polyamide separation layer and a substrate layer, and it is widely used in fields such as water softening and wastewater treatment. However, when filtering high-temperature feed liquids, traditional nanofiltration membranes often undergo thermal deformation or membrane material degradation, resulting in a significant reduction in their separation performance. Specifically, the difference in chemical structure and physical interaction between the polyamide separation layer and the substrate layer causes the nanofiltration membrane to easily deform at high temperatures, thereby affecting the selectivity and retention ability of the membrane.

[0003] In fields such as food processing, chemical engineering, and pharmaceuticals, high-temperature liquid separation is involved. High-temperature resistant nanofiltration membranes can directly filter high-temperature feed liquids, significantly improving the process efficiency and stability compared to traditional nanofiltration membranes, reducing energy consumption, and conforming to the trend of green manufacturing.

[0004] The preparation of high-temperature resistant nanofiltration membranes needs to consider the thermal stability of both the polyamide separation layer and the porous substrate. Strategies such as changing interfacial polymerization monomers, adjusting interfacial polymerization temperature, and introducing inorganic components can improve the thermal stability of the polyamide separation layer. For example, Chinese patent document CN118491316A discloses a high-temperature resistant nanofiltration membrane based on rigid amine monomers, a preparation method thereof, and an application thereof. This invention uses a solution containing rigid amine monomers and an oil-phase solution containing polyfunctional acyl chloride monomers to carry out an interfacial polymerization reaction on a porous support membrane to prepare a high-temperature resistant nanofiltration membrane. The rigid amine monomers are selected from 3,3'-dihydroxybenzidine, 3,3'-dimethylbenzidine, 3,3'-diaminobenzidine, 2,2'-benzidine disulfonic acid, etc. Chinese patent document CN115672031A discloses a high-temperature resistant composite nanofiltration membrane and a preparation method thereof. The high-temperature resistant composite nanofiltration membrane includes a substrate membrane and a polyamide membrane disposed on the substrate membrane; the polyamide membrane includes the following raw material components: amine substances, inorganic salts, silane additives, polyfunctional acyl chlorides, and an oil-phase solvent; the silane additives include at least one of 3-aminopropyltriethoxysilane, diethylenetriaminepropyltrimethoxysilane, N-cyclohexyl-γ-aminopropyltrimethoxysilane, and trimethoxy[3-(phenylamino)propyl]silane.

[0005] Although the above methods have improved the thermal stability of the polyamide separation layer, the thermal stability of the porous substrate layer has not been effectively solved. Therefore, how to improve the long-term stability and separation performance of the nanofiltration membrane in a high-temperature environment has become an urgent technical problem to be solved. Summary of the Invention

[0006] The present invention provides a high-temperature resistant nanofiltration membrane reinforced by inorganic atomic layers and a preparation method thereof. By modifying a porous substrate membrane through atomic layer deposition (ALD) technology, inorganic atomic layers are introduced onto the porous substrate membrane, and then an interfacial polymerization method is used to prepare a polyamide separation layer. The inorganic atomic layers can relieve the interfacial stress between the porous substrate membrane and the polyamide separation layer, increase the mechanical strength of the nanofiltration membrane, and slow down the thermal deformation of the porous substrate membrane under high-temperature conditions, thereby improving the high-temperature stability of the nanofiltration membrane and ensuring that it can still maintain excellent nanofiltration performance in a high-temperature environment.

[0007] The specific technical solution adopted is as follows:

[0008] A preparation method of a high-temperature resistant nanofiltration membrane reinforced by inorganic atomic layers, comprising the following steps:

[0009] (1) Place the polymer porous substrate membrane in an atomic layer deposition reaction chamber. Under vacuum conditions, introduce a metal source precursor into the reaction chamber in a pulsed manner for deposition. After purging with a purge gas, introduce an oxygen source precursor into the reaction chamber in a pulsed manner for reaction, and then purge with the purge gas. Repeat the above deposition - purge - reaction - purge steps multiple times to obtain a modified porous substrate membrane;

[0010] (2) After an interfacial polymerization reaction occurs between an aqueous solution containing an amine monomer and a surfactant and an oil phase solution containing a polyvalent acyl chloride monomer on the modified porous substrate membrane, cure and crosslink to prepare the high-temperature resistant nanofiltration membrane reinforced by inorganic atomic layers;

[0011] The metal source precursor is selected from at least one of a zinc source, a titanium source, or an aluminum source;

[0012] The oxygen source precursor includes deionized water.

[0013] As a technology capable of precisely controlling the film thickness and uniformity, atomic layer deposition (ALD) technology usually deposits continuous single-layer films on a substrate in a reaction chamber under sub-atmospheric pressure. By alternately supplying deposition precursors to the substrate surface in pulses, film growth on the substrate is achieved. The core advantage of ALD technology lies in its ability to precisely control the thickness of the deposition layer at the nanoscale and uniformly deposit inorganic atomic layers on the substrate surface.

[0014] The polymer porous substrate membrane includes, but is not limited to, polyethersulfone (PES), polysulfone (PS), polyvinylidene fluoride membrane (PVDF), polyacrylonitrile (PAN), polyethylene (PE), or polypropylene membrane (PP), etc.

[0015] Preferably, the zinc source is at least one of zinc diethyldichloride, diethylzinc, zinc acetate, and zinc chloride; the titanium source is at least one of titanium tetrachloride, diisopropyltitanium dichloride, and diethyltitanium; the aluminum source is at least one of trimethylaluminum, triethylaluminum, aluminum oxychloride, and aluminum chloride.

[0016] The temperatures of both the metal source precursor and the oxygen source precursor are 50 - 120°C, and the temperatures of the transport pipelines are also 50 - 120°C; the purge gas is nitrogen.

[0017] Preferably, in each deposition - purge - reaction - purge process, the deposition time of the metal source precursor is 20 - 100 ms, and after deposition, wait for 2 - 100 s before purging with the purge gas. The reaction time of the oxygen source precursor is 10 - 50 ms, and after deposition, wait for 1 - 50 s before purging with the purge gas.

[0018] During the deposition - purge - reaction - purge process, the temperature in the atomic layer deposition reaction chamber is 60 - 120°C, and the pressure is 10 - 200 Pa; the deposition - purge - reaction - purge steps are repeated 10 - 800 times.

[0019] Interfacial polymerization forms a polyamide network through the continuous nucleophilic substitution reaction of amine monomers and polyacyl chloride monomers at the water - oil two - phase interface. Among them, the diffusion of amine monomers in the aqueous phase and the diffusion from the aqueous phase to the oil phase will significantly affect the cross - linking degree of the polyamide network.

[0020] Optionally, the amine monomer is at least one of piperazine, m - phenylenediamine, 3,3’ - diaminobenzidine, 3,3’ - dihydroxybenzidine, 3,3’ - dimethylbenzidine, 4,4’ - diaminodiphenylsulfone, 4,4’ - diaminodiphenyl disulfide, 4,4’ - diaminostilbene - 2,2’ - disulfonic acid, 4,4’ - diaminodiphenyl ether - 2,2’ - disulfonic acid, 10H - phenothiazine - 2,8 - diamine, 10H - phenoxazine - 2,8 - diamine, and 3,6 - diamino - 9 - acridone.

[0021] Preferably, the polyacyl chloride monomer is at least one of trimesoyl chloride, isophthaloyl chloride, and terephthaloyl chloride.

[0022] Preferably, the oil - phase solvent is at least one of n - hexane, cyclohexane, n - heptane, isoparaffin, toluene, and ethyl acetate.

[0023] Preferably, the surfactant is selected from at least one of sodium dodecyl sulfonate, sodium dodecene benzene sulfonate, sodium stearate, linear alkyl benzene sulfonate, sodium alkylphenol polyoxyethylene ether sulfonate, and sodium eicosyl sulfate; in the aqueous solution, the concentration of the amine monomer is 0.1-10 wt%, and the concentration of the surfactant is 0.01%-0.1 wt%; in the oil phase solution, the concentration of the polyacyl chloride monomer is 0.15-15 wt%.

[0024] Preferably, the interfacial polymerization reaction temperature is 25-90 °C (further 40-90 °C), the interfacial polymerization reaction time is 0.2-20 min, the curing and crosslinking temperature is 50-90 °C, and the curing and crosslinking time is 2-60 min.

[0025] Adding a surfactant and increasing the reaction temperature can improve the diffusion of the amine monomer and form a denser polyamide separation layer.

[0026] The present invention also provides an inorganic atomic layer enhanced high-temperature nanofiltration membrane prepared by the preparation method of the inorganic atomic layer enhanced high-temperature nanofiltration membrane described above.

[0027] The present invention also provides a filtration method for high-temperature feed liquid, using the inorganic atomic layer enhanced high-temperature nanofiltration membrane described above.

[0028] Furthermore, the temperature of the high-temperature feed liquid is preferably 40-85 °C.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] (1) The present invention uses atomic layer deposition technology to precisely control the thickness of the inorganic atomic layer, making the modified layer uniform and thickness adjustable. The inorganic atomic layer can effectively improve the mechanical strength of the polymer porous substrate membrane, reduce the influence of thermal deformation on the performance of the porous substrate membrane, improve the thermal stability of the membrane, and relieve the interlayer stress between the base layer and the polymer separation layer at high temperatures.

[0031] (2) During the interfacial polymerization process, the addition of a surfactant and the increase in the interfacial polymerization temperature are beneficial to the formation of a denser polyamide separation layer and improve the nanofiltration performance of the product nanofiltration membrane.

[0032] (3) The inorganic atomic layer enhanced high-temperature nanofiltration membrane prepared by the present invention has excellent nanofiltration performance. At 85 °C, the water flux can reach 40 L·m -2 ·h -1 ·bar -1 , and the rejection rates of inorganic salts such as sodium sulfate and magnesium sulfate are greater than 99%. It has a high rejection rate for divalent anion salts and a high permeation rate for monovalent anion salts, showing a salt separation effect.

[0033] (4) The high-temperature-resistant nanofiltration membrane prepared by the present invention can maintain excellent nanofiltration performance for a long time under the high-temperature condition of 85 °C, avoiding serious thermal deformation and performance degradation of traditional nanofiltration membranes at high temperatures. Description of the Drawings

[0034] Figure 1 It is a scanning electron microscope photograph of the surface of a polyvinylidene fluoride ultrafiltration membrane.

[0035] Figure 2 It is a scanning electron microscope photograph of the surface of the zinc-source modified porous substrate membrane in Example 1.

[0036] Figure 3 It is a scanning electron microscope photograph of the surface of the high-temperature-resistant nanofiltration membrane enhanced by inorganic atomic layers in Example 1. Detailed Embodiments

[0037] The detailed embodiments of the present invention will be elaborated in detail below in combination with examples and drawings. It should be noted that the said examples are only exemplary contents, aiming to help understand the present invention and do not limit the protection scope of the present invention. Any modification, supplement, or substitution made by any person skilled in the art based on the embodiments of the present invention without creative labor shall be regarded as within the protection scope of the present invention.

[0038] Example 1: High-Temperature-Resistant Nanofiltration Membrane with Zinc-Source Modified PVDF Substrate

[0039] In this example, a polyvinylidene fluoride (PVDF) ultrafiltration membrane was selected as the polymer porous substrate membrane, and zinc atomic layers were uniformly deposited on the membrane surface by atomic layer deposition (ALD) technology. Diethylzinc dichloride was used as the metal source precursor, and deionized water was used as the oxygen source precursor. Under vacuum conditions, the metal source precursor was introduced into the reaction chamber in a pulsed form for deposition for 50 ms. After deposition, wait for 30 s and then use the purge gas to purge and discharge the unadsorbed metal source precursor. Then, the oxygen source precursor was introduced into the reaction chamber in a pulsed form for reaction for 50 ms. After the reaction, wait for 30 s and then use the purge gas to purge and discharge the unreacted oxygen source precursor and reaction by-products. During the deposition-purge-reaction-purge process, the temperature in the atomic layer deposition reaction chamber was 100 °C, the pressure was 50 Pa, the temperatures of both the metal source precursor and the oxygen source precursor were 100 °C, and the temperatures of the transport pipelines were all 100 °C; repeat the above deposition-purge-reaction-purge steps 100 times to obtain the zinc-source modified porous substrate membrane;

[0040] The zinc source-modified porous substrate membrane was immersed in an aqueous solution (containing 0.2 wt% piperazine and 0.05 wt% sodium dodecyl sulfate). After the aqueous solution fully infiltrated the membrane surface, it was taken out. The membrane treated with the aqueous solution was put into a trimesoyl chloride organic phase solution (the concentration of trimesoyl chloride was 0.15 wt%, and the solvent was n-hexane), and an interfacial polymerization reaction was carried out at 60 °C for 5 min. After the reaction was completed, the membrane product was taken out and cured at 60 °C for 10 min, and finally a high-temperature-resistant nanofiltration membrane enhanced by inorganic atomic layers (i.e., a high-temperature-resistant nanofiltration membrane with a zinc source-modified PVDF substrate) was obtained.

[0041] Example 2: High-temperature-resistant nanofiltration membrane with a titanium source-modified PVDF substrate

[0042] The difference between the preparation method of the high-temperature-resistant nanofiltration membrane with inorganic atomic layer enhancement in this example and that in Example 1 is only that titanium tetrachloride is used as the metal source precursor, and other reaction steps and process parameters are the same.

[0043] Example 3: High-temperature-resistant nanofiltration membrane with an aluminum source-modified PVDF substrate

[0044] The difference between the preparation method of the high-temperature-resistant nanofiltration membrane with inorganic atomic layer enhancement in this example and that in Example 1 is only that trimethylaluminum is used as the metal source precursor, and other reaction steps and process parameters are the same.

[0045] Example 4: High-temperature-resistant nanofiltration membrane with a zinc source-modified PVDF substrate

[0046] The difference between the preparation method of the high-temperature-resistant nanofiltration membrane with inorganic atomic layer enhancement in this example and that in Example 1 is only that the temperature in the atomic layer deposition reaction chamber is 60 °C and the pressure is 100 Pa, and other reaction steps and process parameters are the same.

[0047] Example 5: High-temperature-resistant nanofiltration membrane with a zinc source-modified PVDF substrate

[0048] The difference between the preparation method of the high-temperature-resistant nanofiltration membrane with inorganic atomic layer enhancement in this example and that in Example 1 is only that during each deposition-purge-reaction-purge process, the metal source precursor is introduced into the reaction chamber in a pulsed form for deposition for 100 ms, and after deposition, wait for 100 s and then use the purge gas to purge and discharge the unadsorbed metal source precursor, and other reaction steps and process parameters are the same.

[0049] Example 6: High-temperature-resistant nanofiltration membrane with a zinc source-modified PVDF substrate

[0050] The difference between the preparation method of the high-temperature-resistant nanofiltration membrane with inorganic atomic layer enhancement in this example and that in Example 1 is only that the deposition-purge-reaction-purge steps are repeated 50 times, and other reaction steps and process parameters are the same.

[0051] Comparative Example 1: Thin-film composite nanofiltration membrane with an unmodified PVDF substrate

[0052] The unmodified PVDF membrane was immersed in an aqueous solution (containing 0.2 wt% piperazine), and after the aqueous solution fully wetted the membrane surface, it was taken out. The membrane treated with the aqueous solution was put into a trimesoyl chloride organic phase solution (the concentration of trimesoyl chloride was 0.15 wt%, and the solvent was n - hexane). The interfacial polymerization reaction was carried out at 25 °C for 5 min. After the reaction was completed, the membrane product was taken out and cured at 60 °C for 10 min, and finally a thin - layer composite nanofiltration membrane was obtained.

[0053] Sample analysis

[0054] In order to comprehensively evaluate the performance of the modified membrane, the prepared different membrane samples were subjected to morphology analysis, high - temperature nanofiltration performance evaluation, and long - term stability test.

[0055] (1) Morphology analysis

[0056] The surface morphologies of the PVDF ultrafiltration membrane, the zinc - source - modified porous substrate membrane in Example 1, and the inorganic atomic - layer - enhanced high - temperature nanofiltration membrane in Example 1 were characterized by scanning electron microscopy (SEM), as shown respectively in Figures 1 - 3 shown, Figure 1 It can be seen that the PVDF ultrafiltration membrane has some nano - level pore structures. After modification by the ALD method, nanoparticles are uniformly distributed on the membrane surface ( Figure 2 ), and further after the interfacial polymerization reaction between the aqueous solution containing piperazine and surfactant and the trimesoyl chloride hexane solution, a continuous and dense polyamide separation layer appears on the surface of the obtained inorganic atomic - layer - enhanced high - temperature nanofiltration membrane, and the surface has a granular morphology (such as Figure 3 ).

[0057] (2) High - temperature nanofiltration performance of the inorganic atomic - layer - enhanced high - temperature nanofiltration membrane

[0058] The surface charge property of the nanofiltration membrane enables it to achieve the screening of charged substances through the Donnan effect. The residual acyl chloride groups on the surface of the nanofiltration membrane can be hydrolyzed into carboxyl groups, so it is usually negatively charged and can effectively retain high - valence anions. In this invention, the nanofiltration performance of the nanofiltration membrane was evaluated by water flux and rejection rate. In this invention, the nanofiltration performance of different membrane samples for magnesium sulfate aqueous solution under high - temperature environment was evaluated. The results are shown in Table 1. As the temperature increases, Example 1 (the high - temperature nanofiltration membrane with zinc - source - modified PVDF substrate) is superior to Comparative Example 1 (the thin - layer composite nanofiltration membrane with unmodified PVDF substrate) in both water flux and rejection rate of magnesium sulfate. The water flux of the high - temperature nanofiltration membrane in Example 1 increases significantly with the increase of temperature, and at the same time, the rejection rate of magnesium sulfate almost remains above 99%.

[0059] Table 1 High - temperature nanofiltration performance of the nanofiltration membranes in Comparative Example 1 and Example 1 for magnesium sulfate aqueous solution

[0060]

[0061] As can be seen from Table 1, the water fluxes of the nanofiltration membranes in Comparative Example 1 and Example 1 gradually increased with the increase of the feed solution temperature. Further tests also involved the membrane samples of Examples 2-6, and their nanofiltration performance for different solutions (magnesium sulfate, sodium sulfate, sodium chloride, and magnesium chloride) at 85 °C was evaluated. The results are shown in Table 2. The inorganic atomic layer-enhanced high-temperature-resistant nanofiltration membranes prepared in Examples 2-6 have excellent nanofiltration performance, and the rejection rates for sodium sulfate and magnesium sulfate exceed 99%.

[0062] Table 2 High-temperature nanofiltration performance of the nanofiltration membranes in Examples 2-6 for aqueous solutions of magnesium sulfate and sodium sulfate

[0063]

[0064] As can be seen from Table 3, the high-temperature nanofiltration membranes of Examples 1-6 showed good water fluxes (about 40 L·m 2 ·h -1 ·bar -1 ) and relatively low rejection rates for aqueous solutions of sodium chloride and magnesium chloride at 85 °C. This performance difference is mainly due to the stronger electrostatic repulsion of the negative charge on the membrane surface towards divalent anions (such as SO 4 2- ), while the effect on monovalent anions (such as Cl - , MgCl 2 ) is weaker. The modification with different metal sources (such as zinc, titanium, and aluminum) has little effect on the membrane performance, indicating the dominant role of atomic layer deposition technology in improving the membrane performance. These membranes have good high-temperature stability and are suitable for high-temperature applications such as seawater desalination and ion sieving.

[0065] Table 3 High-temperature nanofiltration performance of the nanofiltration membranes in Examples 1-6 for aqueous solutions of sodium chloride and magnesium chloride

[0066]

[0067] (3) Stability of the inorganic atomic layer-enhanced high-temperature-resistant nanofiltration membrane

[0068] To test the stability of the membrane, a long-term operation evaluation was carried out at 85 °C. Table 4 shows the changes in the water flux and magnesium sulfate rejection rate of the inorganic atomic layer-enhanced high-temperature-resistant nanofiltration membrane in Example 1 within 120 days. The results show that the membrane can still maintain a relatively high water flux and stable rejection rate under long-term high-temperature operation, demonstrating its excellent high-temperature stability.

[0069] Table 4 Water flux and magnesium sulfate rejection rate of the nanofiltration membrane in Example 1 under long-term operation at 85 °C

[0070]

[0071]

[0072] The embodiments described above have elaborated on the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, supplements, or substitutions in a similar manner within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an inorganic atomic layer-enhanced high-temperature resistant nanofiltration membrane, characterized in that: The following steps are involved: (1) placing a polymer porous substrate membrane in an atomic layer deposition reaction chamber, introducing a metal source precursor into the reaction chamber in a pulsed form for deposition under vacuum conditions, purging with a purge gas, then introducing an oxygen source precursor into the reaction chamber in a pulsed form for reaction, then purging with a purge gas, and repeating the above deposition-purge-reaction-purge steps multiple times to obtain a modified porous substrate membrane; (2) allowing an aqueous solution containing amine monomers and surfactants to undergo an interfacial polymerization reaction with an oily solution containing polyacyl chloride monomers on a modified porous substrate membrane, followed by curing and crosslinking to prepare the inorganic atomic layer-enhanced high-temperature resistant nanofiltration membrane; The metal source precursor is selected from at least one of a zinc source, a titanium source or an aluminum source; The oxygen source precursor includes deionized water.

2. The method for preparing the inorganic atomic layer enhanced high temperature resistant nanofiltration membrane according to claim 1, characterized in that: The zinc source is selected from at least one of zinc diethyl dichloride, diethyl zinc, zinc acetate, and zinc chloride; the titanium source is selected from at least one of titanium tetrachloride, diisopropyl titanium dichloride, and diethyl titanium; and the aluminum source is selected from at least one of trimethyl aluminum, triethyl aluminum, aluminum chloride, and aluminum chloride.

3. The method for preparing the inorganic atomic layer enhanced high temperature resistant nanofiltration membrane according to claim 1, characterized in that: In each deposition-purge-reaction-purge process, the deposition time of the metal source precursor is 20-100ms, and after deposition, wait for 2-100s before purging with the purge gas. The reaction time of the oxygen source precursor is 10-50ms, and after deposition, wait for 1-50s before purging with the purge gas.

4. The method for preparing the inorganic atomic layer enhanced high temperature resistant nanofiltration membrane according to claim 1, characterized in that: During the deposition-purge-reaction-purge process, the temperature in the atomic layer deposition reaction chamber is 60-120° C. and the pressure is 10-200 Pa; the deposition-purge-reaction-purge steps are repeated 10-800 times.

5. The method for preparing the inorganic atomic layer enhanced high temperature resistant nanofiltration membrane according to claim 1, characterized in that: The amine monomer is selected from at least one of piperazine, m-phenylenediamine, 3,3'-diaminobenzidine, 3,3'-dihydroxybenzidine, 3,3'-dimethylbenzidine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl disulfide, 4,4'-diaminostilbene-2,2'-disulfonic acid, 4,4'-diaminodiphenyl ether-2,2'-disulfonic acid, 10H-phenothiazine-2,8-diamine, 10H-phenoxazine-2,8-diamine, and 3,6-diamino-9-acridone.

6. The method for preparing the inorganic atomic layer enhanced high temperature resistant nanofiltration membrane according to claim 1, characterized in that: The polyacyl chloride monomer is selected from at least one of trimesoyl chloride, isophthaloyl chloride and terephthaloyl chloride.

7. The method for preparing the inorganic atomic layer enhanced high temperature resistant nanofiltration membrane according to claim 1, characterized in that: The surfactant is selected from at least one of sodium dodecyl sulfonate, sodium dodecenylbenzene sulfonate, sodium stearate, sodium linear alkylbenzene sulfonate, sodium alkylphenol polyoxyethylene ether sulfonate, and sodium eicosyl sulfate; in the aqueous phase solution, the concentration of the amine monomer is 0.1-10wt%, and the concentration of the surfactant is 0.01%-0.1wt%; in the oil phase solution, the concentration of the polyacyl chloride monomer is 0.15-15wt%.

8. The method for preparing the inorganic atomic layer enhanced high temperature resistant nanofiltration membrane according to claim 1, characterized in that: The interface polymerization reaction temperature is 25-90° C., the interface polymerization reaction time is 0.2-20 min, the curing and cross-linking temperature is 50-90° C., and the curing and cross-linking time is 2-60 min.

9. An inorganic atomic layer reinforced high temperature resistant nanofiltration membrane obtained according to the method for preparing an inorganic atomic layer reinforced high temperature resistant nanofiltration membrane according to any one of claims 1 to 8.

10. A method for filtering high-temperature liquid, characterized in that: A high temperature resistant nanofiltration membrane reinforced by the inorganic atomic layer as described in claim 9.

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