Green super-efficient rapid purification method of porous material

Abstract

The invention discloses a green super-efficient rapid purification method of a porous material, which utilizes a Soxhlet extraction device comprising an extraction cylinder, a condenser pipe, a flask and a siphon and a nano-micron percolation cylinder arranged in the extraction cylinder to purify the porous material, and comprises the following steps: S1, filling the nano-micron percolation cylinder with the porous material to be purified, the outer diameter of the nano-micron percolation cylinder is smaller than the inner diameter of the extraction cylinder; s2, adding a purification solvent into the flask, heating to boil, and enabling solvent steam to flow into the extraction cylinder after being condensed by a condensation pipe; s3, in the Soxhlet extraction process, a pressure difference is generated at the upper part and the lower part of the nano-micron percolation barrel by utilizing a temperature gradient formed at the upper part and the lower part in the extraction barrel; and S4, after the purification is finished, separating the porous material from the purification solvent, and drying to obtain the pure porous material. The device is simple and convenient to operate, has the dual advantages of environmental protection, high efficiency and economy, has good industrial potential, and provides a reliable purification solution for the porous material.

Description

Technical Field

[0001] This invention relates to the field of porous material purification technology, specifically a green, ultra-efficient, and rapid purification method for porous materials. Background Technology

[0002] Porous materials, including zeolite molecular sieves, mesoporous materials, metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and disordered porous materials, play a crucial role in catalysis, adsorption separation, energy storage, and environmental remediation due to their high specific surface area, tunable pore structure, and active sites. The performance of these materials is highly sensitive to purity: residual impurities significantly reduce effective pore volume, increase mass transfer resistance, mask active sites, and weaken structural stability. In other words, the purity of a material directly determines its effective pore volume, diffusion resistance, active site exposure, and long-term stability. Therefore, developing efficient, mild, and environmentally friendly purification processes is a key prerequisite for advancing porous materials from laboratory research to industrial applications.

[0003] Currently, the purification of porous materials mainly relies on repeated soaking and washing with organic solvents to remove residual template agents, unreacted monomers, and byproducts from the synthesis process. However, this method has inherent limitations: (1) molecular diffusion within the pores is restricted, the purification cycle often lasts for several days, and it is difficult to completely remove embedded impurities; (2) the process steps are cumbersome, batch consistency is poor, and it is difficult to achieve stable scale-up; (3) the solvent consumption is large, resulting in significant cost and environmental burden; (4) frequent liquid-phase treatment and chemical shock can easily cause framework damage (such as molecular sieve dealuminization, MOF structure collapse, etc.), which weakens the intrinsic properties of the material. Existing technologies cannot achieve an effective balance between purification efficiency, material integrity, and environmental friendliness, which has become a bottleneck for the application of porous materials in high-value scenarios.

[0004] Existing methods for purifying porous materials using Soxhlet extraction devices simply involve placing the crude product into a glass sample tube or filter paper sleeve and extracting it for an extended period in solvents such as methanol or ethanol. This type of method essentially still relies on passive immersion and periodic solvent replacement for purification, thus offering limited improvement in mass transfer efficiency and purification rate within the pores. Improvements to Soxhlet extraction devices mainly focus on structural modifications such as temperature control and direct-flow heat collection. For example, patent CN101940849A discloses a method with an outer tube surrounding the inner tube, a temperature-controlled liquid circulating between the outer and inner tubes to maintain a specific temperature in the inner tube, and a serpentine tube positioned between them. The condensed solvent flows back into the inner tube through the serpentine tube, where it is also kept at a controlled temperature by the temperature-controlled liquid, allowing the extraction process to proceed at the required temperature. However, this technological improvement is primarily limited to optimizing the temperature field within the inner tube and the macroscopic extraction efficiency, failing to achieve effective purification of porous materials. Patent CN102861456A discloses... One type of Soxhlet extractor with slow heat dissipation, easy temperature control, and high extraction efficiency features a straight-through inner tube heat collector. While improvements in this type focus on extraction efficiency and temperature control, they still struggle to effectively address issues such as long purification cycles, high solvent consumption, and susceptibility to material damage during the purification process of porous materials. Furthermore, Soxhlet extractors such as CN202322295988U, which add an "extraction purification core" inside the extraction cylinder, primarily use packing material to simultaneously purify the extract. The purification core typically employs an open structure and is more suited for the extraction and purification of general analytical samples. It is not specifically designed to address the characteristics of porous materials, such as easy particle loss, narrow pore depth, and sensitivity to skeletal structures, nor does it fundamentally optimize the flow pattern of solvent within the porous material bed.

[0005] In summary, there is an urgent need for a novel purification strategy that leverages the properties of porous materials to achieve efficient, rapid, and low-solvent-consumption purification under mild conditions. This strategy should thoroughly remove impurities while significantly shortening the purification cycle and reducing solvent capacity, ensuring that the crystal structure and pore integrity of the material remain intact. This will provide solid technical support for the large-scale preparation and widespread application of high-performance porous materials. Summary of the Invention

[0006] The purpose of this invention is to overcome the fatal flaws of existing porous material purification technologies, such as complex operation, lengthy cycle, high solvent consumption, and incomplete impurity removal, and to provide a green, rapid, and efficient method for purifying porous materials. This method significantly improves purification efficiency and substantially reduces solvent usage while ensuring the integrity of the material structure and the scalability of the process.

[0007] This invention utilizes the combined effect of pressure difference caused by the temperature gradient within the system and the siphon effect to drive rapid, automatic, and bidirectional circulation of solvent between the cylindrical inner part and the extraction cylinder, thereby achieving efficient and continuous purification of porous materials. In the single-pass structure, the residual gas in the upper part of the cylinder expands due to heat, pushing the solvent downwards to penetrate the material layer; in the double-pass structure, the solvent in the upper part continuously exerts hydraulic pressure on the lower part, propelling the solvent circulation. Both structures accelerate the solvent replacement process by enhancing the pressure difference, significantly improving mass transfer efficiency and effectively reducing solvent loss.

[0008] On the one hand, the objective of this invention is achieved through the following technical solution: a green, ultra-efficient, and rapid purification method for porous materials, utilizing a Soxhlet extraction device including an extraction cylinder 2, a condenser 1, a flask 6, a connecting tube 5, and a siphon tube 4, and a nano-micron percolation cylinder 3 disposed inside the extraction cylinder to purify the porous material, comprising the following steps: S1. The porous material to be purified is packed into the nano-microfiltration cartridge, the outer diameter of the nano-microfiltration cartridge is smaller than the inner diameter of the extraction cartridge, and together with the extraction cartridge, they form an annular flow channel for solvent circulation; S2. Add the purified solvent to the flask and heat it to boiling, so that the solvent vapor is condensed by the condenser and flows into the extraction cylinder; S3. During the Soxhlet extraction process, the temperature gradient formed in the upper and lower parts of the extraction cylinder is used to create a pressure difference between the upper and lower parts of the nano-microfiltration cylinder. With the help of the periodic siphon action of the siphon tube, the purification solvent is driven to penetrate the porous material bed from top to bottom, and an automatic, bidirectional forced percolation flow is formed between the nano-microfiltration cylinder and the extraction cylinder, thereby achieving rapid, continuous and efficient purification of the porous material. S4. After purification, the porous material is separated from the purification solvent and dried to obtain a pure porous material.

[0009] Specifically, the nano-micro filter cartridge remains filled with purification solvent during the purification process to enhance the pressure difference drive and circulation purification effect; Specifically, the nano-micro permeation cartridge includes single-pass and double-pass cylindrical structures, wherein the lower end of the single-pass structure is closed by a nano-micro membrane, and both the upper and lower ends of the double-pass structure are closed by nano-micro membranes; Specifically, the nano-micro membrane is a nano- to micro-scale porous membrane, and its pore size is adapted and selected according to the particle size distribution of the porous material to be purified, so as to ensure that the purification solvent can pass freely and completely trap the porous material particles. Specifically, the purification solvent is selected according to the type of porous material to be purified, including one or more of N,N-dimethylformamide, ethanol, methanol, and deionized water.

[0010] On the other hand, the green, ultra-efficient, and rapid purification device system for porous materials in the purification method includes a Soxhlet extraction device and a nano-micron permeation cartridge; The Soxhlet extraction apparatus includes a condenser, an extraction cylinder, and a flask. The condenser is located at the upper end of the extraction cylinder, and the flask is located at the lower end of the extraction cylinder. A siphon tube is provided at the bottom of the extraction cylinder. The siphon tube rises and folds back before being inserted into the ground glass joint of the flask. The nano-micro permeation cartridge is disposed inside the extraction cartridge as an internal component for filling porous material. The nano-micro permeation cartridge is a single-pass or double-pass cylindrical structure. The lower end of the single-pass structure is composed of a nano-micro membrane, and the upper and lower ends of the double-pass structure are composed of nano-micro membranes. The outer diameter of the nano-microfiltration cartridge is smaller than the inner diameter of the extraction cartridge. Its height and relative position with the siphon tube create a pressure difference through the temperature difference between the upper and lower parts of the cartridge during device operation, and under the siphon effect, the purification solvent is driven to form an automatic, bidirectional circulation flow between the nano-microfiltration cartridge and the extraction cartridge. Specifically, the nano-microfiltration cartridge is made of a material that is resistant to high temperature, high pressure and solvent corrosion; Specifically, the nano-micro membrane includes a 0.1 μm polytetrafluoroethylene filter membrane or an equivalent nano- to micron-sized porous filter membrane; Specifically, the inner volume of the nano-microfiltration cartridge and its fit with the extraction cartridge ensure that the nano-microfiltration cartridge is always filled with purification solvent during normal operation of the device.

[0011] Furthermore, the green, ultra-efficient, and rapid purification method for porous materials in this application is applied to the purification and post-processing of porous materials.

[0012] The beneficial effects of this application are: (1) This application utilizes the pressure difference formed by the temperature gradient in the system, in conjunction with the inherent siphon effect of Soxhlet extraction, to transform the traditional passive permeation into a cycle-driven process, thereby accelerating the flow and replacement speed of the solvent in the porous material bed, shortening the purification cycle, and achieving the goal of "ultra-efficient and rapid" purification. (2) This application constructs a closed, self-circulating solvent path. The purification solvent is automatically circulated in both directions within the system under pressure difference and siphon action. It is repeatedly and efficiently utilized, overcoming the disadvantage of huge solvent consumption in traditional column purification and other one-time column passing methods. It significantly reduces raw material costs and further reduces the discharge of toxic and harmful organic waste liquids, which is in line with the development direction of green chemistry. (3) The nano-micro filter cartridge design adopted in this application can be precisely adapted to the particle size of porous materials. It can ensure complete interception of tiny porous material particles in high-speed circulation flow, effectively preventing material loss. The entire process is carried out under gentle heating, avoiding damage to the fine structure of porous materials by violent operation or strong shear force, and providing reliable protection for subsequent production. Attached Figure Description

[0013] Figure 1 A comparison chart of purification time, unit consumption of purification solvent, and BET value between the purification method of this application and traditional purification. Figure 2 The PXRD characterization diagrams of the phase structure of the purified MIL-101-S / J in Example 1 and Comparative Example 1 are shown (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 3 The following are PXRD characterization diagrams of the phase structure of ZIF-8-S / J after purification in Example 2 and Comparative Example 2 (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 4 The PXRD characterization diagrams of the purified MOF-199-S / J in Example 3 and Comparative Example 3 are shown (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 5 The PXRD characterization diagrams of the purified MOF-5-S / J phase structure in Example 4 and Comparative Example 4 are shown (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 6 The PXRD characterization diagrams of the purified MOF-801-S / J in Example 5 and Comparative Example 5 are shown (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 7 The following are the phase structure (PXRD) characterization diagrams of the 4A MS-S / J purified material in Example 6 and Comparative Example 6 (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 8 The following are PXRD characterization diagrams of the phase structure after purification by 5A MS-S / J in Example 7 and Comparative Example 7 (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 9 The following are characterization diagrams of the phase structure (PXRD) of the 13X MS-S / J purified material in Example 8 and Comparative Example 8 (where the horizontal axis is the diffraction angle 2θ and the vertical axis is the diffraction intensity). Figure 10 This is a physical image of the device used in this application (the inside of the extraction cylinder is a single-channel nano-micron percolation cylinder). Figure 11 This is a physical image of the device used in this application (the inside of the extraction cylinder is a double-channel nano-microfiltration cylinder). Figure 12This is a schematic diagram of the device described in this application; Figure labels: 1-condenser, 2-extraction tube, 3-nano-micron leakage tube, 4-siphon tube, 5-connecting tube, 6-flask. Detailed Implementation

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0015] Green, ultra-efficient, and rapid purification device systems using porous materials, such as Figure 12 As shown, the device includes a condenser 1, an extraction cylinder 2, a nano-microfiltration cylinder 3, a siphon tube 4, a connecting pipe 5, and a flask 6. The condenser is located at the upper end of the extraction cylinder, and the flask is located at the lower end of the extraction cylinder. A siphon tube is located at the bottom of the extraction cylinder. The siphon tube rises and folds back before inserting into the ground glass joint of the flask. The nano-microfiltration cylinder is located inside the extraction cylinder and serves as an internal component for filling porous material. The nano-microfiltration cylinder has a single-pass or double-pass cylindrical structure. The lower end of the single-pass structure is composed of a nano-micro membrane, and both ends of the double-pass structure are composed of nano-micro membranes. The outer diameter of the nano-microfiltration cylinder is smaller than the inner diameter of the extraction cylinder. Its height and relative position with the siphon tube create a pressure difference between the upper and lower parts of the cylinder during device operation due to the temperature difference.

[0016] The following examples and comparative examples all used the same batch of porous materials. Under the premise of achieving similar purification effects (measured by indicators such as specific surface area), the purification time required for the two methods was determined, and the same purification solvent separation conditions and vacuum drying post-treatment steps were used to ensure that the performance difference only originated from the purification stage. S: Method of the present invention; J: Traditional immersion method.

[0017] Example 1: Rapid purification of MIL-101-S using this method The MIL-101-S to be purified was placed in a cylindrical container with a 0.1 μm polytetrafluoroethylene filter membrane sealed at one end. DMF was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. DMF was added to a round-bottom flask and heated to 145–160 °C for 1 hour of continuous purification. The material was then removed, centrifuged, and the purification process was repeated using ethanol as a solvent. After centrifugation again and drying at 85 °C, pure MIL-101-S was obtained. The purified phase structure characterization diagram is shown below. Figure 2 As shown.

[0018] Comparative Example 1: Traditional Immersion Purification of MIL-101-J Take the same batch of MIL-101-J and soak it in DMF at room temperature, changing the solvent every 24 hours for 3 days; then repeat the same operation with ethanol. After soaking, treat it under the same centrifugation and drying conditions as in Example 1. The purified phase structure characterization diagram is shown below. Figure 2 As shown.

[0019] Example 2: Rapid purification of ZIF-8-S using this method The ZIF-8-S to be purified was placed in a cylindrical container with a 0.1 μm polytetrafluoroethylene filter membrane sealed at one end. Anhydrous ethanol was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. Anhydrous ethanol was added to a round-bottom flask and heated to 80–98 °C for 1 hour of continuous purification. After centrifugation, the material was vacuum dried at 85 °C to obtain pure ZIF-8-S. The purified phase structure characterization diagram is shown below. Figure 3 As shown.

[0020] Comparative Example 2: Traditional Immersion Purification of ZIF-8-J Take ZIF-8-J from the same batch, soak it in anhydrous ethanol at room temperature, changing the solvent every 24 hours for 3 days, and then treat it under the same centrifugation and vacuum drying conditions as in Example 2. The purified phase structure characterization diagram is shown below. Figure 3 As shown.

[0021] Example 3: Rapid purification of MOF-199-S using this method The MOF-199-S to be purified was placed in a cylindrical container with a 0.1 μm polytetrafluoroethylene filter membrane sealed at one end. Anhydrous ethanol was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. Anhydrous ethanol was added to a round-bottom flask and heated to 80–98 °C for 1 hour of continuous purification. After centrifugation, the material was dried under vacuum at 85 °C to obtain pure MOF-199-S. The purified phase structure characterization diagram is shown below. Figure 4 As shown.

[0022] Comparative Example 3: Traditional Immersion Purification of MOF-199-J Take MOF-199-J from the same batch, soak it in anhydrous ethanol at room temperature, changing the solvent every 24 hours for 3 days, and then treat it under the same centrifugation and vacuum drying conditions as in Example 3. The purified phase structure characterization diagram is shown below. Figure 4 As shown.

[0023] Example 4: Rapid purification of MOF-5-S using this method The MOF-5-S to be purified was placed in a cylindrical container with a 0.1 μm polytetrafluoroethylene filter membrane sealed at one end. Anhydrous methanol was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. Anhydrous methanol was added to a round-bottom flask and heated to 75–95 °C for 1 hour of continuous purification. After centrifugation, the material was dried under vacuum at 85 °C to obtain pure MOF-5-S. The purified phase structure characterization diagram is shown below. Figure 5 As shown.

[0024] Comparative Example 4: Traditional Immersion Purification of MOF-5-J Take MOF-5-J from the same batch, soak it in anhydrous methanol at room temperature, changing the solvent every 24 hours for 3 days, and then treat it under the same centrifugation and vacuum drying conditions as in Example 4. The purified phase structure characterization diagram is shown below. Figure 5 As shown.

[0025] Example 5: Rapid purification of MOF-801-S using this method The MOF-801-S to be purified was placed in a cylindrical container with a 0.1 μm polytetrafluoroethylene filter membrane sealed at one end. Deionized water was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. A round-bottom flask containing deionized water was heated to 95–105 °C and purified for 1 hour. After centrifugation, the purification steps were repeated using ethanol as a solvent. The mixture was centrifuged again and dried at 85 °C to obtain pure MOF-801-S. The purified phase structure characterization diagram is shown below. Figure 6 As shown.

[0026] Comparative Example 5: Traditional Immersion Purification of MOF-801-J Take MOF-801-J from the same batch and soak it sequentially in deionized water and ethanol at room temperature, changing the solvent every 24 hours for 3 days each time. Then, treat it under the same centrifugation and drying conditions as in Example 5. The purified phase structure characterization diagram is shown below. Figure 6 As shown.

[0027] Example 6: Rapid purification of 4A molecular sieve (MS) using this method The 4A MS-S to be purified was placed in a cylindrical container sealed with a filter membrane at one end. Deionized water was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. Deionized water was added to a round-bottom flask and heated to 95–105°C for 1 hour. After filtration, the material was removed and the purification steps were repeated using ethanol as a solvent. The mixture was filtered again and dried at 85°C to obtain pure 4A MS-S. The purified phase structure is shown in the figure below. Figure 7 As shown.

[0028] Comparative Example 6: Traditional Immersion Purification of MS-J Take 4A MS-J from the same batch and soak it sequentially in deionized water and ethanol at room temperature, changing the solvent every 24 hours for 3 days each time. Then, treat it under the same filtration and drying conditions as in Example 6. The purified phase structure characterization diagram is shown below. Figure 7 As shown.

[0029] Example 7: Rapid purification of 5A MS-S using this method The 5A MS-S to be purified was placed in a cylindrical container with a filter membrane sealed at one end. Deionized water was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. Deionized water was added to a round-bottom flask and heated to 95–105 °C for 1 hour. After filtration, the material was removed and the purification steps were repeated using ethanol as a solvent. The mixture was filtered again and dried at 85 °C to obtain pure 5A MS-S. The purified phase structure is shown in the figure below. Figure 8 As shown.

[0030] Comparative Example 7 5A MS-J Traditional Immersion Purification Take 5A MS-J from the same batch and soak it sequentially in deionized water and ethanol at room temperature, changing the solvent every 24 hours for 3 days each time. Then, treat it under the same filtration and drying conditions as in Example 7. The purified phase structure characterization diagram is shown below. Figure 8 As shown.

[0031] Example 8: Rapid purification of 13X MS-S using this method The 13X MS-S to be purified was placed in a cylindrical container sealed with a filter membrane at one end. Deionized water was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. Deionized water was added to a round-bottom flask and heated to 95–105 °C for 1 hour. After filtration, the material was removed and the purification steps were repeated using ethanol as a solvent. The mixture was filtered again and dried at 85 °C to obtain pure 13X MS-S. The purified phase structure is shown in the figure below. Figure 9 As shown.

[0032] Comparative Example 8: Traditional Immersion Purification of MS-J Take 13X MS-J from the same batch and soak it sequentially in deionized water and ethanol at room temperature, changing the solvent every 24 hours for 3 days each time. Then, treat it under the same filtration and drying conditions as in Example 8. The purified phase structure characterization diagram is shown below. Figure 9 As shown.

[0033] Example 9 Rapid purification of activated carbon-S using this method The activated carbon to be purified was placed in a cylindrical container with a filter membrane sealed at one end. Deionized water was added, and the other end was sealed. The container was then placed in a Soxhlet extraction apparatus. Deionized water was added to a round-bottom flask and heated to 95-105°C for 1 hour. After filtration, the material was removed and the purification steps were repeated using ethanol as a solvent. The mixture was then filtered again and dried at 85°C to obtain pure activated carbon-S.

[0034] Comparative Example 9: Traditional Immersion Purification of Activated Carbon-J Take activated carbon from the same batch and soak it in deionized water and ethanol at room temperature, changing the solvent every 24 hours for 3 days each time. Then, treat it under the same filtration and drying conditions as in Example 9.

[0035] The unit consumption of purification solvent and corresponding purification cycles of the porous materials in Examples 1-9 and Comparative Examples are listed in Table 1. Their BET specific surface areas were measured using a Micromeritics ASAP 2460 gas adsorption analyzer, and the specific values ​​are summarized in Table 2. A performance comparison of the two methods is shown below. Figure 1 .

[0036] Table 1. Comparison of time and solvent consumption required for purifying porous materials using the traditional immersion method and the present invention. Table 2 Comparison of specific surface area of ​​porous materials purified by two methods (traditional method and this invention) As shown in Table 1, the purification time of this invention is only 1.39% of that of the traditional immersion method, demonstrating a significant efficiency advantage. Average statistical experiments show that the purification time for a single cycle of this invention is 10 minutes, while the traditional method requires 24 hours. The solvent cycle time for this invention is also only 0.69% of that of the traditional process. Regarding solvent consumption, the traditional method requires 3–6 L of solvent per gram of porous material for purification, while this invention stably controls the amount to 0.3 L. In terms of solvent consumption, this invention is only 5–10% of the traditional method. For low-solvent-consumption systems such as ZIF-8 and MOF-199, the solvent saving rate can reach 90%; for high-solvent-consumption systems such as MIL-101 and molecular sieves, the saving rate is as high as 95%, highlighting its green and environmentally friendly advantages.

[0037] As shown in Table 2, after purification using the method of this invention, the specific surface area of ​​the porous materials can approach the theoretically reported peak value. The BET specific surface area is increased by 38.8% to 185% compared to traditional purification methods, proving that this method can deeply unclog pores and avoid blockage by residual impurities. It is worth noting that the increase in BET specific surface area is related to material characteristics: MOF materials with more complex pore structures, such as ZIF-8, show better improvement than molecular sieve materials with relatively simple structures, indicating that this invention is more targeted at cleaning and activating the pores of high-porosity materials. In summary, the nine porous materials with different pore sizes, structures, and chemical compositions all show a consistent optimization trend: significantly shortened purification time, significantly reduced solvent consumption, and effectively increased specific surface area, with no exceptions. This fully demonstrates that the technical advantages of this invention are universal and unaffected by differences in the inherent properties of the materials themselves.

[0038] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A green, ultra-efficient, and rapid purification method for porous materials, characterized in that: The purification of porous materials using a Soxhlet extraction apparatus comprising an extraction cylinder, a condenser, a flask, and a siphon tube, and a nano-micron percolation filter cartridge disposed inside the extraction cylinder, includes the following steps: S1. The porous material to be purified is packed into the nano-microfiltration cartridge, the outer diameter of the nano-microfiltration cartridge is smaller than the inner diameter of the extraction cartridge, and together with the extraction cartridge, they form an annular flow channel for solvent circulation; S2. Add the purified solvent to the flask and heat it to boiling, so that the solvent vapor is condensed by the condenser and flows into the extraction cylinder; S3. During the Soxhlet extraction process, the temperature gradient formed in the upper and lower parts of the extraction cylinder is used to create a pressure difference between the upper and lower parts of the nano-microfiltration cylinder. With the help of the periodic siphon action of the siphon tube, the purification solvent is driven to penetrate the porous material bed from top to bottom, and an automatic, bidirectional forced percolation flow is formed between the nano-microfiltration cylinder and the extraction cylinder, thereby achieving rapid, continuous and efficient purification of the porous material. S4. After purification, the porous material is separated from the purification solvent and dried to obtain a pure porous material.

2. The purification method according to claim 1, characterized in that: The nano-micron percolation cartridge remains filled with purification solvent during the purification process to enhance the pressure difference drive and circulation purification effect.

3. The purification method according to claim 1, characterized in that: The nano-microfiltration cartridge includes single-pass and double-pass cylindrical structures, wherein the lower end of the single-pass structure is closed by a nano-micro membrane, and both the upper and lower ends of the double-pass structure are closed by nano-micro membranes.

4. The purification method according to claim 1, characterized in that: The nano-micro membrane is a nano- to micro-sized porous membrane, and its pore size is adapted to the particle size distribution of the porous material to be purified, so as to ensure that the purification solvent can pass freely and completely retain the porous material particles.

5. The purification method according to claim 1, characterized in that: The purification solvent is selected according to the type of porous material to be purified, including one or more of N,N-dimethylformamide, ethanol, methanol, and deionized water.

6. A green, ultra-efficient, and rapid purification device system for porous materials used in implementing the purification method according to any one of claims 1 to 4, characterized in that: Including Soxhlet extraction devices and nano-microfiltration cartridges; The Soxhlet extraction apparatus includes a condenser, an extraction cylinder, and a flask. The condenser is located at the upper end of the extraction cylinder, and the flask is located at the lower end of the extraction cylinder. A siphon tube is provided at the bottom of the extraction cylinder. The siphon tube rises and folds back before being inserted into the ground glass joint of the flask. The nano-micro permeation cartridge is disposed inside the extraction cartridge as an internal component for filling porous material. The nano-micro permeation cartridge is a single-pass or double-pass cylindrical structure. The lower end of the single-pass structure is composed of a nano-micro membrane, and the upper and lower ends of the double-pass structure are composed of nano-micro membranes. The outer diameter of the nano-microfiltration cartridge is smaller than the inner diameter of the extraction cartridge. Its height and relative position to the siphon tube create a pressure difference through the temperature difference between the upper and lower parts of the cartridge during device operation. Under the siphon effect, the purification solvent is driven to form an automatic, bidirectional circulation flow between the nano-microfiltration cartridge and the extraction cartridge.

7. The device system according to claim 5, characterized in that: The nano-micron percolation cartridge is made of a material that is resistant to high temperature, high pressure and solvent corrosion.

8. The device system according to claim 5, characterized in that: The nano-micro membrane includes a 0.1 μm polytetrafluoroethylene filter membrane or an equivalent nano- to micron-sized porous filter membrane.

9. The device system according to claim 5, characterized in that: The internal volume of the nano-microfiltration cartridge and its fit with the extraction cartridge ensure that the nano-microfiltration cartridge remains filled with purification solvent during normal operation of the device.

10. The application of the purification method according to any one of claims 1 to 5 or the apparatus system according to any one of claims 6 to 9 in the purification and post-treatment process of porous materials.

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