Fluorine-containing aromatic polyamide film as well as preparation method and application thereof
Fluorinated aromatic polyamide films were prepared by interfacial polymerization technology, which solved the problems of low flux and poor selectivity of existing membrane materials in the separation of nonpolar solvents, and realized efficient and easily scalable separation of hydrocarbons, especially crude oil fractionation.
Patent Information
- Application Number
- CN202511441335.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-10
- Publication Date
- 2025-11-14
AI Technical Summary
Existing membrane materials have low flux and poor selectivity in the separation of nonpolar solvents, making them difficult to apply on a large scale. Furthermore, their preparation processes are complex and costly.
Fluorinated aromatic polyamide films were prepared by interfacial polymerization technology. Fluorinated aromatic diamine monomers were reacted with polyacrylamide monomers to form a porous support layer and a fluorinated polyamide selective layer. Process parameters were optimized to achieve efficient separation.
It significantly improves the permeation flux of nonpolar solvents, maintains good retention rates for macromolecular solutes, enables differentiated separation of different hydrocarbons, is suitable for the separation of complex hydrocarbons, and is easy to scale up for production.
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Figure CN120939773A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of separation membrane material technology, specifically relating to a fluorinated aromatic polyamide film, its preparation method, and its application. Background Technology
[0002] Crude oil is a complex hydrocarbon mixture, often referred to as the "lifeblood of industry." As a major source of fossil fuels, plastics, and polymers, its efficient separation is crucial for global industrialization. Currently, industrial fractionation of crude oil primarily utilizes thermal distillation, but this process is extremely energy-intensive, accounting for approximately 1% of global energy consumption annually. Therefore, there is an urgent need to develop next-generation low-carbon separation technologies.
[0003] Membrane separation technology, due to its phase-change-free nature, is considered one of the energy-saving alternatives to traditional distillation. Among them, organic solvent reverse osmosis (OSRO) technology utilizes sub-nanometer pores to achieve molecular-level sieving, showing promising potential in crude oil fractionation. However, the practical application of OSRO technology is limited by the development of high-performance membrane materials. Although research has proposed novel membrane materials such as spirocyclic polymers and polytriazoles, their preparation processes are complex and costly, making large-scale application difficult.
[0004] Therefore, developing an OSRO membrane material that combines good hydrophobicity, high separation performance, and ease of large-scale preparation has become the key to promoting the industrialization of membrane-based crude oil fractionation technology. Summary of the Invention
[0005] The purpose of this invention is to solve the problems of low flux and poor selectivity of existing membrane materials in the separation of non-polar solvents, and to provide a fluorinated aromatic polyamide film, its preparation method and application.
[0006] This invention optimizes interfacial polymerization process parameters to prepare a highly efficient separation membrane—a fluorinated aromatic polyamide film—with adjustable separation performance for the separation of hydrocarbons (such as crude oil). The fluorinated aromatic polyamide film is prepared by interfacial polymerization technology and has good hydrophobicity, high separation performance, and is easy to prepare on a large scale.
[0007] A fluorinated aromatic polyamide film includes a porous support layer and a fluorinated polyamide selective layer formed by interfacial polymerization;
[0008] The fluorinated polyamide selective layer is composed of a fluorinated aromatic diamine monomer. With polyacryl chloride monomers The reaction is formed, and the reaction formula is as follows:
[0009] Where R is -CF3, -OCF3, -CH(CF3)2 or -C(CF3)3.
[0010] A method for preparing a fluorinated aromatic polyamide film is specifically carried out according to the following steps:
[0011] I. Preparation of aqueous solution:
[0012] ① Dissolve the fluorinated aromatic diamine monomer in an organic co-solvent to obtain solution I;
[0013] ② Dissolve the surfactant, acid absorbent, and pore structure protectant in water to obtain solution II;
[0014] ③ Mix solution I and solution II thoroughly to obtain an aqueous solution;
[0015] The fluorinated aromatic diamine monomer mentioned in step one is , , or ;
[0016] II. Preparation of organic phase solution:
[0017] The polyacryl chloride monomer is dissolved in a nonpolar organic solvent to obtain an organic phase solution;
[0018] The polyacrylamide chloride monomer mentioned in step two is pyromellitic trimethylolpropionate chloride;
[0019] III. Interface Aggregation:
[0020] An aqueous solution was coated onto a porous support membrane. After standing for a certain period of time, excess liquid was removed, and an organic solution was then coated onto the membrane for interfacial polymerization. After the reaction was completed, the membrane was heat-treated to obtain a fluorinated aromatic polyamide film, which was then stored in isopropanol.
[0021] Application of a fluorinated aromatic polyamide film in hydrocarbon separation;
[0022] The hydrocarbons include binary mixtures of toluene and 1,3,5-triisopropylbenzene, multi-component mixtures of toluene and various hydrocarbon compounds, and real crude oil dissolved in toluene;
[0023] The crude oil contains straight-chain alkanes, branched-chain alkanes, cycloalkanes, monocyclic aromatics, and polycyclic aromatics.
[0024] The present invention has the following beneficial effects:
[0025] I. This invention significantly enhances the hydrophobicity of the membrane by introducing fluorine-containing groups, thereby greatly increasing the permeation flux of nonpolar solvents (toluene flux > 0.1 L·m). -2 ·h -1 ·bar -1 It also maintains a good retention rate for macromolecular solutes (1,3,5-triisopropylbenzene retention rate >50%).
[0026] II. This invention can effectively separate mixtures of multi-component organic compounds, exhibiting differentiated separation performance for different types of hydrocarbons (including straight-chain alkanes, branched-chain alkanes, cycloalkanes, monocyclic aromatics, polycyclic aromatics, etc.), achieving precise sieving based on molecular size and affinity.
[0027] Third, this invention can effectively separate real crude oil and achieve enrichment of light components in crude oil;
[0028] IV. By adjusting the proportion of organic co-solvents in the aqueous solution and the heat treatment temperature, this invention can achieve precise control of membrane separation performance, meeting the needs of different crude oil fractionation applications.
[0029] V. This invention is based on mature interfacial polymerization technology, with a simple preparation process, mild conditions, and easy large-scale production;
[0030] VI. The fluorine-containing structure enhances the membrane's resistance to swelling and chemical stability, making it suitable for organic solvent environments;
[0031] VII. The fluorinated aromatic polyamide film prepared by this invention has important industrial application value in the field of complex hydrocarbon separation (such as crude oil separation). Attached Figure Description
[0032] Figure 1 A scanning electron microscope image of the surface of the fluorinated aromatic polyamide film prepared in Example 1;
[0033] Figure 2 The permeation flux diagrams were obtained by separating the binary mixture of toluene and 1,3,5-triisopropylbenzene using the fluorinated aromatic polyamide films prepared in Examples 1-3.
[0034] Figure 3 The fluorinated aromatic polyamide films prepared in Examples 1-3 were used to separate the binary mixture of toluene and 1,3,5-triisopropylbenzene, and the resulting rejection rate diagrams were obtained.
[0035] Figure 4 The graph shows the retention rates of different hydrocarbons when the fluorinated aromatic polyamide film prepared in Example 1 is separated from a mixture of toluene and various hydrocarbon compounds.
[0036] Figure 5 The graph shows the rejection rates of different hydrocarbons when the fluorinated aromatic polyamide film prepared in Example 2 separates toluene from a mixture of various hydrocarbon compounds.
[0037] Figure 6 The graph shows the rejection rates of different hydrocarbons when the fluorinated aromatic polyamide film prepared in Example 3 is separated from a mixture of toluene and various hydrocarbon compounds.
[0038] Figure 7The chromatograms of the feed liquid and permeate of crude oil separation prepared by the fluorinated aromatic polyamide membrane in Example 3 are shown. Detailed Implementation
[0039] Specific Implementation Method 1: This implementation method: A fluorinated aromatic polyamide film, comprising a porous support layer and a fluorinated polyamide selective layer formed by interfacial polymerization;
[0040] The fluorinated polyamide selective layer is composed of a fluorinated aromatic diamine monomer. With polyacryl chloride monomers The reaction is formed, and the reaction formula is as follows:
[0041] Where R is -CF3, -OCF3, -CH(CF3)2 or -C(CF3)3.
[0042] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the porous support layer is made of polyacrylonitrile. All other steps are the same as in Specific Implementation Method One.
[0043] Specific Implementation Method 3: This implementation method is a method for preparing a fluorinated aromatic polyamide film, specifically completed according to the following steps:
[0044] I. Preparation of aqueous solution:
[0045] ① Dissolve the fluorinated aromatic diamine monomer in an organic co-solvent to obtain solution I;
[0046] ② Dissolve the surfactant, acid absorbent, and pore structure protectant in water to obtain solution II;
[0047] ③ Mix solution I and solution II thoroughly to obtain an aqueous solution;
[0048] The fluorinated aromatic diamine monomer mentioned in step one is , , or ;
[0049] II. Preparation of organic phase solution:
[0050] The polyacryl chloride monomer is dissolved in an organic solvent to obtain an organic phase solution;
[0051] The polyacrylamide chloride monomer mentioned in step two is pyromellitic trimethylolpropionate chloride;
[0052] III. Interface Aggregation:
[0053] An aqueous solution was coated onto a porous support membrane. After standing for a certain period of time, excess liquid was removed, and an organic solution was then coated onto the membrane for interfacial polymerization. After the reaction was completed, the membrane was heat-treated to obtain a fluorinated aromatic polyamide film, which was then stored in isopropanol.
[0054] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: the organic co-solvent mentioned in step one is methanol or ethanol; the surfactant is sodium dodecyl sulfate; the acid absorbent is triethylamine; and the pore structure protectant is camphor sulfonic acid. The other steps are the same as in Specific Implementation Methods One to Three.
[0055] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: the mass ratio of organic co-solvent to water in the aqueous solution in step one is (0.05~1):1; and the mass fraction of the fluorinated aromatic diamine monomer in the aqueous solution in step one is 0.5wt%~3.0wt%. The other steps are the same as in Specific Implementation Methods One to Four.
[0056] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: the mass fraction of the surfactant in the aqueous solution in step one is 0.1wt% to 0.5wt%; the mass fraction of the acid absorbent in the aqueous solution in step one is 0.5wt% to 4wt%; and the mass fraction of the pore structure protectant in the aqueous solution in step one is 0.5wt% to 8wt%. The other steps are the same as in Specific Implementation Methods One to Five.
[0057] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that: the organic solvent in step two is n-hexane; the mass fraction of the polyacrylamide chloride monomer in the organic phase solution in step two is 0.05wt%~0.3wt%. The other steps are the same as in Specific Implementation Methods One to Six.
[0058] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: the settling time in step three is 1 to 10 minutes; the interfacial polymerization reaction time in step three is 1 to 10 minutes. Other steps are the same as in Specific Implementation Methods One to Seven.
[0059] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: the volume ratio of the aqueous phase solution to the organic phase solution in step three is 1:1; the heat treatment temperature in step three is 60℃~100℃, and the heat treatment time is 2min~10min. Other steps are the same as in Specific Implementation Methods One to Eight.
[0060] Specific Implementation Method 10: This implementation method is an application of a fluorinated aromatic polyamide film in hydrocarbon separation;
[0061] The hydrocarbons include binary mixtures of toluene and 1,3,5-triisopropylbenzene, multi-component mixtures of toluene and various hydrocarbon compounds, and real crude oil dissolved in toluene;
[0062] The crude oil contains straight-chain alkanes, branched-chain alkanes, cycloalkanes, monocyclic aromatics, and polycyclic aromatics.
[0063] The beneficial effects of the present invention are verified using the following embodiments:
[0064] Example 1: A method for preparing a fluorinated aromatic polyamide film, specifically comprising the following steps:
[0065] I. Preparation of aqueous solution:
[0066] ① Dissolve 0.4 g of fluorinated aromatic diamine monomer in 1.26 g of methanol, sonicate and stir until homogeneous to obtain solution I;
[0067] ② Dissolve 0.05 g sodium dodecyl sulfate, 0.80 g camphor sulfonic acid and 0.4 g triethylamine in 17.08 g deionized water to obtain solution II;
[0068] ③ Mix solution I and solution II thoroughly to obtain an aqueous solution;
[0069] The fluorinated aromatic diamine monomer mentioned in step one is ;
[0070] II. Preparation of organic phase solution:
[0071] Dissolve 0.075 g of pyromellitic acid chloride in 49.925 g of n-hexane, sonicate, and stir until homogeneous to obtain an organic phase solution;
[0072] III. Interface Aggregation:
[0073] An aqueous solution was applied to a porous support membrane, and after standing for 5 minutes, excess liquid was removed. Then, an organic solution was applied to the membrane for interfacial polymerization for 2 minutes. After the reaction, the membrane was heat-treated at 75°C for 5 minutes to obtain a fluorinated aromatic polyamide film, which was then stored in isopropanol.
[0074] Example 2: The difference between this example and Example 1 is: 1. Preparation of the aqueous solution:
[0075] ① Dissolve 0.4 g of fluorinated aromatic diamine monomer in 9.175 g of methanol, sonicate and stir until homogeneous to obtain solution I;
[0076] ② Dissolve 0.05 g sodium dodecyl sulfate, 0.80 g camphor sulfonic acid and 0.4 g triethylamine in 9.175 g deionized water to obtain solution II;
[0077] ③ Mix solution I and solution II thoroughly to obtain an aqueous solution. All other steps and parameters are the same as in Example 1.
[0078] Example 3: The difference between this example and Example 1 is that after the reaction in step three, the membrane is heat-treated at 100°C for 5 minutes to obtain a fluorinated aromatic polyamide film, which is then stored in isopropanol. All other steps and parameters are the same as in Example 1.
[0079] The following performance tests were performed on Examples 1 to 3:
[0080] (1) Retention rate of 1,3,5-triisopropylbenzene: The fluorinated aromatic polyamide membrane provided in the example was added to the pressure assembly, and a binary mixture of toluene and 1,3,5-triisopropylbenzene (molar ratio of toluene to 1,3,5-triisopropylbenzene = 99:1) was added. Reverse osmosis membrane separation was performed at room temperature and 20 bar pressure. The relative contents of toluene and 1,3,5-triisopropylbenzene in the permeate were tested by gas chromatography to obtain the retention rate of 1,3,5-triisopropylbenzene.
[0081] (2) Permeation flux of binary mixture of toluene and 1,3,5-triisopropylbenzene: The permeation flux of the fluorinated aromatic polyamide composite membrane to the binary mixture of toluene and 1,3,5-triisopropylbenzene was tested by measuring the mass of the permeate sample from the outflow pressure component at regular intervals.
[0082] (3) Retention rate of various hydrocarbon compounds: The fluorinated aromatic polyamide membrane provided in the example was added to the pressure assembly, and a multi-component mixture of toluene and various hydrocarbons was added (the molar percentage of toluene was 85, and the percentage of each of the other hydrocarbons was 1). Reverse osmosis membrane separation was carried out at room temperature and pressure of 20 bar. The relative content of toluene and various hydrocarbons in the permeate was tested by gas chromatography to obtain the retention rate of various hydrocarbon compounds.
[0083] (4) Real crude oil separation: The membrane is added to the pressure unit, and a mixture of toluene and real crude oil (volume ratio 9:1) is added. Reverse osmosis separation is carried out at room temperature and 25 bar pressure. The composition of feed liquid and permeate is analyzed by gas chromatography to evaluate the separation effect of the membrane.
[0084] Test results are as follows Figures 2-7 As shown in Table 1-2.
[0085] Figure 1 A scanning electron microscope image of the surface of the fluorinated aromatic polyamide film prepared in Example 1;
[0086] from Figure 1 It can be seen that the fluorinated aromatic polyamide film exhibits a wrinkled, leaf-like structure, similar to the morphology of traditional aromatic polyamide films.
[0087] Table 1
[0088]
[0089] The results in Table 1 show that a series of membranes with different separation performances in the p-toluene / TIPB binary system can be prepared by adjusting two simple process parameters. Users can choose the appropriate preparation conditions according to the different priorities of flux or rejection rate in actual applications.
[0090] Table 2
[0091]
[0092] Table 2 shows that the membrane exhibits differentiated separation performance for hydrocarbons with similar molecular weights but different structures. For example, there is a significant difference in the rejection rates for n-octane (straight-chain alkane) and isooctane (branched-chain alkane), indicating that the membrane has molecular structure recognition capabilities. Simultaneously, the membrane shows a negative rejection rate for certain aromatic compounds (such as naphthalene and biphenyl), indicating that these compounds exhibit specific adsorption or preferential transport within the membrane, which provides the possibility for the separation and enrichment of specific components. Furthermore, the separation performance of the membrane for various hydrocarbon compounds can be adjusted by changing the preparation conditions. Example 3 shows a higher rejection rate for most hydrocarbons, demonstrating that membrane materials meeting different separation performance requirements can be obtained through process adjustments.
[0093] Figure 7 The results, obtained using gas chromatography, clearly show that Example 3 effectively separated crude oil and achieved the enrichment of light components with less than 15 carbon atoms in the crude oil.
[0094] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.
Claims
1. A fluorinated aromatic polyamide film, characterized in that... The fluorinated aromatic polyamide film includes a porous support layer and a fluorinated polyamide selective layer formed by interfacial polymerization. The fluorinated polyamide selective layer is composed of a fluorinated aromatic diamine monomer. With polyacryl chloride monomers The reaction is formed, and the reaction formula is as follows: Where R is -CF3, -OCF3, -CH(CF3)2 or -C(CF3)3.
2. The fluorinated aromatic polyamide film according to claim 1, characterized in that... The porous support layer is polyacrylonitrile.
3. The method for preparing a fluorinated aromatic polyamide film as described in claim 1, characterized in that... The preparation method is specifically carried out according to the following steps: I. Preparation of aqueous solution: ① Dissolve the fluorinated aromatic diamine monomer in an organic co-solvent to obtain solution I; ② Dissolve the surfactant, acid absorbent, and pore structure protectant in water to obtain solution II; ③ Mix solution I and solution II thoroughly to obtain an aqueous solution; The fluorinated aromatic diamine monomer mentioned in step one is , , or ; II. Preparation of organic phase solution: The polyacryl chloride monomer is dissolved in an organic solvent to obtain an organic phase solution; The polyacrylamide chloride monomer mentioned in step two is pyromellitic trimethylolpropionate chloride; III. Interface Aggregation: An aqueous solution was coated onto a porous support membrane. After standing for a certain period of time, excess liquid was removed, and an organic solution was then coated onto the membrane for interfacial polymerization. After the reaction was completed, the membrane was heat-treated to obtain a fluorinated aromatic polyamide film, which was then stored in isopropanol.
4. The method for preparing a fluorinated aromatic polyamide film according to claim 3, characterized in that... The organic cosolvent mentioned in step one is methanol or ethanol; the surfactant is sodium dodecyl sulfate; the acid absorbent is triethylamine; and the pore structure protectant is camphor sulfonic acid.
5. The method for preparing a fluorinated aromatic polyamide film according to claim 3, characterized in that... The mass ratio of organic co-solvent to water in the aqueous solution in step one is (0.05~1):1; the mass fraction of fluorinated aromatic diamine monomer in the aqueous solution in step one is 0.5wt%~3.0wt%.
6. The method for preparing a fluorinated aromatic polyamide film according to claim 3, characterized in that... The mass fraction of the surfactant in the aqueous solution in step one is 0.1wt%~0.5wt%; the mass fraction of the acid absorbent in the aqueous solution in step one is 0.5wt%~4wt%; and the mass fraction of the pore structure protectant in the aqueous solution in step one is 0.5wt%~8wt%.
7. The method for preparing a fluorinated aromatic polyamide film according to claim 3, characterized in that... The organic solvent mentioned in step two is n-hexane; the mass fraction of the polyacrylamide chloride monomer in the organic phase solution mentioned in step two is 0.05wt%~0.3wt%.
8. The method for preparing a fluorinated aromatic polyamide film according to claim 3, characterized in that... The settling time in step three is 1 min to 10 min; the interfacial polymerization reaction time in step three is 1 min to 10 min.
9. The method for preparing a fluorinated aromatic polyamide film according to claim 3, characterized in that... The volume ratio of the aqueous phase solution to the organic phase solution in step three is 1:1; the temperature of the heat treatment in step three is 60℃~100℃, and the heat treatment time is 2min~10min.
10. The application of the fluorinated aromatic polyamide film as described in claim 1, characterized in that... Application of a fluorinated aromatic polyamide film in hydrocarbon separation; The hydrocarbons include binary mixtures of toluene and 1,3,5-triisopropylbenzene, multi-component mixtures of toluene and various hydrocarbon compounds, and real crude oil dissolved in toluene; The crude oil contains straight-chain alkanes, branched-chain alkanes, cycloalkanes, monocyclic aromatics, and polycyclic aromatics.