Low-pressure-drop particulate matter filtering material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of materials, and discloses a low-pressure-drop particulate matter filtering material as well as a preparation method and application thereof. The low-pressure-drop particulate matter filtering material with a fluffy three-dimensional multi-level structure is prepared through controllable self-assembly of collagen. The low-pressure-drop particulate matter filtering material prepared in the invention can realize long-acting interception of various particulate matters under low pressure drop.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials and particulate filtration, and particularly relates to a low-pressure-drop particulate filtration material, a preparation method thereof, and an application thereof. Background Art

[0002] Currently, particulate matter (PMs) is one of the major air pollutants (Lelieveld J, Evans J S, Fnais M, et al. The contribution of outdoor air pollution sources to premature mortality on a global scale[J]. Nature, 2015, 525: 367-371. Xu R B, Ye T T, Yue X, et al. Global population exposure to landscape fire air pollution from 2000 to 2019[J]. Nature, 2023, 621: 521-529. Fang D L, Chen B, Hubacek K, et al. Clean air for some: unintended spillover effects of regional air pollution policies[J]. Sci. Adv., 2019, 5: eaav4707. Ezzati M, Lopez A D, Rodgers A, et al. Selected major risk factors and global and regional burden of disease[J]. The Lancet, 2002, 360: 1347.).Filter materials based on size sieving strategies are currently widely used for PMs filtration (Tian Z Y, Lei Y, Ye X Y, at al. Efficient capture of airbornePM by nanotubularconjugated microporous polymers based filters under harshconditions[J]. J.Hazard. Mater., 2022, 423: 127047. Liu H, Zhang S C, Liu LF, et al. A fluffy dual-network structured nanofiber / net filter enable high-efficiency airfiltration[J]. Adv. Funct. Mater., 2019, 29: 1904108.Lei Y,Wang S Z, Jiang Y L, et al. A robust triphenylamine-based monolithic polymernetwork for selective sieving of CO。 2and PM from flue gas[J]. Sci. Total Environ., 2024, 946: 174463. Choi S J, Jeon H, Jang M, et al. Biodegradable, efficient, and breathable multi-use face mask filter[J]. Adv. Sci., 2021, 8: 2003155.). Generally, filter materials use pores smaller than the diameter of PMs for filtration, which leads to the easy blockage of the pores of filter materials by PMs during long-term filtration, resulting in high pressure drop problems, material blockage and pollution, and it is difficult to achieve long-term filtration (Song K P, Pan Y T, He J Y, et al. Coordination bond cleavage of metal-organic frameworks and application to flame-retardant polymeric materials[J]. Ind. Chem. Mater., 2024, 2: 556-570. Xiao Z H, Shan S, Wang Y X, et al. Harvesting multicolor photoluminescence in nonaromatic interpenetrated metal-organic framework nanocrystals via pressure-modulated carbonyls aggregation[J]. Adv. Mater. 2024, 36: 2403281. Yao M S, Tang W X, Wang G E, et al. MOF thin film-coated metal oxide nanowire array: significantly improved chemiresistor sensor performance[J]. Adv. Mater., 2016, 28: 5229-5234.). On the other hand, it is difficult for traditional filter materials to achieve simultaneous low-pressure drop filtration of multiple PMs with different particle sizes. Therefore, there is an urgent need to develop a new type of particulate filter material that can simultaneously filter multiple PMs and has the characteristics of low pressure drop and long-term separation performance.

[0003] In view of this, the present invention is specifically proposed. Summary of the Invention

[0004] To solve the problems in the background art, the first object of the present invention is to provide a low-pressure-drop particulate filtering material, which has a fluffy three-dimensional multi-level structure and has the characteristics of low air resistance air flow transmission.

[0005] The second object of the present invention is to provide a preparation method of a low-pressure-drop particulate filtering material.

[0006] The third object of the present invention is to provide an application of a low-pressure-drop particulate filtering material in filtering particulate matter.

[0007] To achieve the above object, the first technical solution adopted by the present invention is: A low-pressure-drop particulate filtering material, which is a material with a fluffy three-dimensional multi-layer structure formed by self-assembly of collagen.

[0008] Preferably, the collagen is collagen fiber or collagen fiber modified by materials such as metal-organic framework materials, zirconium salts, iron salts, titanium salts, tannins, activated carbon, etc.

[0009] The second technical solution adopted by the present invention is: A preparation method of a low-pressure-drop particulate filtering material, which performs controllable self-assembly on collagen.

[0010] The third technical solution adopted by the present invention is: An application of a low-pressure-drop particulate filtering material in filtering particulate matter.

[0011] Preferably, the particulate matter includes PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 , PM 10 Any one or more of them, so as to achieve simultaneous interception and long-term interception of various particulate matters.

[0012] Compared with the prior art, the present invention has the following beneficial effects: Traditional filter materials achieve the filtration and interception of PMs based on the sieving effect of their dense pores. Since the size of PMs is extremely small, traditional filter materials need to utilize dense pores with extremely small sizes to achieve effective filtration of PMs, which leads to the bottleneck problems of high air resistance and high pressure drop. At the same time, the PMs intercepted by the dense pores are extremely easy to accumulate and block the pores, causing material pollution problems and making it difficult to achieve long-term stable filtration. In addition, traditional filter materials also have the problem of being difficult to simultaneously and long-term separate PMs with different particle sizes. The low-pressure-drop particulate filter material prepared by the present invention is different from traditional filter materials. It realizes the multiple interception of PMs at the micro-nano scale within the confined space with the fluffy three-dimensional multi-level structure constructed by collagen fibers. Therefore, it can effectively filter PMs with different particle sizes and exhibits the characteristics of low pressure resistance. At the same time, the intercepted PMs can be highly dispersed in the fluffy three-dimensional multi-level structure, effectively avoiding the pollution problems caused by serious accumulation of PMs and achieving long-term anti-pollution separation. Therefore, when simultaneously filtering PMs with different particle sizes, it can exhibit filtration performance and long-term performance significantly superior to commercial filter materials. In addition, the PM filtration performance of the low-pressure-drop particulate filter material prepared by the present invention can be effectively regulated by self-assembly of collagen fibers modified with different materials such as metal-organic framework materials, zirconium salts, iron salts, titanium salts, tannins, activated carbon, etc. Description of the Drawings

[0013] Figure 1 Interception efficiency of the low-pressure-drop particulate filter material-1 prepared in Example 1 of the present invention for PM -1 at an air flow velocity of 5.1 m s 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10 ; Figure 2 Mass factor of the low-pressure-drop particulate filter material-1 prepared in Example 1 of the present invention for PM -1 at an air flow velocity of 5.1 m s 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10 ; Figure 3 In (a), (b), (c) in -1 Interception efficiency and mass factor after intercepting PM 0.3 , PM 0.5 , PM 1.0 for 365 minutes at an air flow velocity of 5.1 m s -1 by the single-layer low-pressure-drop particulate filter material-1 prepared in Example 1 of the present invention; Figure 4 In (a), SEM-EDS analysis diagrams after the interception of PMs by each layer of the low-pressure-drop particulate filter material-1 prepared in Example 1 of the present invention for 6, 10, 14, and 18 minutes at an air flow velocity of 5.1 m s -1 are shown. (b), (c), (d), and (e) are FESM-DES analysis diagrams after the interception of PMs by the first, second, third, and fourth layers of the low-pressure-drop particulate filter material-1 prepared in Example 1 of the present invention for 18 minutes at an air flow velocity of 5.1 ms -1 respectively; Figure 5 The interception efficiency of the low-pressure-drop particulate filter material-2 prepared in Example 2 of the present invention for PM -1 , PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 , and PM 10 at an air flow velocity of 5.1 m s is shown; Figure 6 The mass factor of the low-pressure-drop particulate filter material-2 prepared in Example 2 of the present invention for PM -1 , PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 , and PM 10 at an air flow velocity of 5.1 m s is shown; Figure 7 The interception efficiency of the low-pressure-drop particulate filter material-3 prepared in Example 3 of the present invention for PM -1 , PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 , and PM 10 at an air flow velocity of 5.1 m s is shown; Figure 8 The mass factor of the low-pressure-drop particulate filter material-3 prepared in Example 3 of the present invention for PM -1 , PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 , and PM 10 at an air flow velocity of 5.1 m s is shown; Figure 9In (a), (b), and (c) are photos of the low-pressure-drop particulate filter material - 4, low-pressure-drop particulate filter material - 5, and low-pressure-drop particulate filter material - 6 prepared in Example 4 of the present invention; Figure 10 is a photo of the low-pressure-drop particulate filter material - 7 prepared in Example 5 of the present invention; Figure 11 is a photo of the low-pressure-drop particulate filter material - 8 prepared in Example 6 of the present invention; Figure 12 is for the interception efficiency of commercial filter materials (F7, G4, F5, and H10) in Comparative Example 1 for PM -1 at an air flow velocity of 5.1 m s 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 , and PM 10 ; Figure 13 is for the mass factor of commercial filter materials (F7, G4, F5, and H10) in Comparative Example 1 for PM -1 at an air flow velocity of 5.1 m s 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 , and PM 10 . Detailed Embodiments

[0014] The present invention will be specifically described below through examples, and the technical solutions of the present invention are not limited to the following specific embodiments listed, but also include any combination between the specific embodiments.

[0015] It is necessary to point out here that these examples are only used to further illustrate the present invention and cannot be understood as limiting the protection scope of the present invention. For those skilled in the art, some non-essential improvements and adjustments made based on the above invention content are also considered to fall within the protection scope of the present invention.

[0016] The present invention provides a preparation and application of a low-pressure-drop particulate filter material, and the specific implementation scheme is as follows.

[0017] Example 1 (1) Preparation of low-pressure-drop particulate filtration material: Add 5.0 g of collagen fiber (chrome-tanned) to 100 mL of methanol solution containing 1.78 g of zinc nitrate hexahydrate, and stir at 30 °C and 320 rpm for 1.0 h. Subsequently, add 100 mL of methanol solution containing 0.98 g of 2-methylimidazole to the above system. After standing and reacting for 24 h, filter the above mixture with a 200-mesh gauze. After the filter cake is washed with methanol and dried at 50 °C for 5.0 h, add 4.0 g of the intermediate product prepared above and 0.4 g of sodium carboxymethylcellulose to 135 mL of deionized water, and stir at 30 °C and 320 rpm for 3.0 h. Freeze the resulting mixture at -45 o °C for 4.0 h, and freeze-dry at -45 o °C for 72 h to obtain the low-pressure-drop particulate filtration material-1.

[0018] (2) Use the low-pressure-drop particulate filtration material-1 prepared in this example to intercept PMs: Sandwich a layer of low-pressure-drop particulate filtration material-1 between two H-shaped bottles, and connect the two H-shaped bottles to the air flow outlet and air flow inlet of the vacuum pump respectively. Place a burning incense stick in the H-shaped bottle connected to the air flow outlet, and then connect two particle counters to each H-shaped bottle to measure the interception efficiency of the low-pressure-drop particulate filtration material-1 for PMs. In addition, a differential pressure gauge is connected between the two H-shaped bottles to detect the pressure drop of the low-pressure-drop particulate filtration material-1 for intercepting PMs. The interception efficiencies of the low-pressure-drop particulate filtration material-1 for PM -1 at a wind speed of 5.1 m s 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10 are 99.53%, 99.72%, 99.77%, 99.89%, 99.96% and 99.93% respectively (as shown in Figure 1 , the abscissa is the diameter of PMs), the corresponding pressure drop is 40 Pa, and the corresponding mass factors are 0.134, 0.147, 0.152, 0.170, 0.196 and 0.181 respectively (as shown in Figure 2 , the abscissa is the diameter of PMs). As shown in Figure 3 , during long-term interception (365 minutes) at a wind speed of 5.1 m s -1 , the interception efficiencies of the low-pressure-drop particulate filtration material-1 for PM 0.3 , PM 0.5 , PM 1.0 are still higher than 93.29%, 99.16% and 99.30%, and the corresponding mass factors still reach 0.062, 0.060 and 0.062.

[0019] (3) Use the low-pressure-drop particulate filter material-1 prepared in this example to intercept PMs: Stack four layers of low-pressure-drop particulate filter material-1 and sandwich them between two H-shaped bottles. The two H-shaped bottles are respectively connected to the air flow outlet and air flow inlet of the vacuum pump. Place a burning incense stick in the H-shaped bottle connected to the air flow outlet, and intercept for 6, 10, 14, and 18 minutes respectively at a wind speed of 5.1 m s -1 . Subsequently, SEM-DES analysis was performed on the above four layers of low-pressure-drop particulate filter material-1 ( Figure 4 (a)), and potassium element signal was used as the characteristic element for FESM-EDS analysis of each layer of low-pressure-drop particulate filter material-1 ( Figure 4 (b)-(e)). As Figure 4 shown, the signal intensity of potassium element in the first layer (in direct contact with the air inlet end) of the low-pressure-drop particulate filter material-1 gradually increases with the progress of interception, indicating that PMs are gradually intercepted by the first layer of low-pressure-drop particulate filter material. When using four stacked layers of low-pressure-drop particulate filter material-1 to intercept PMs for 18 minutes, the signal intensity of potassium element does not increase sharply in the first layer of low-pressure-drop particulate filter material, and potassium element is also detected in the subsequent three layers of low-pressure-drop particulate filter material. These results indicate that the fluffy channels inside the low-pressure-drop particulate filter material-1 contribute to the transmission of air flow through its four-layer aerogel, enabling PMs to be evenly intercepted inside it without causing serious accumulation or blockage.

[0020] Example 2 (1) Prepare low-pressure-drop particulate filter material: Add 5.0 g of collagen fiber (chrome tanned) to 100 mL of methanol solution containing 1.74 g of cobalt nitrate hexahydrate, and stir at 30 °C and 320 rpm for 1.0 h. Subsequently, add 100 mL of methanol solution containing 0.98 g of 2-methylimidazole to the above system. After standing and reacting for 24 h, filter the above mixture with a 200-mesh gauze. After the filter cake is washed with methanol and dried at 50 °C for 5.0 h, add 4.0 g of the above-prepared intermediate product and 0.4 g of sodium carboxymethylcellulose to 135 mL of deionized water, and stir at 30 °C and 320 rpm for 3.0 h. Freeze the obtained mixture at -45 o °C for 4.0 h, and freeze-dry at -45 o °C for 72 h to obtain the low-pressure-drop particulate filter material-2.

[0021] (2) Use the low-pressure-drop particulate filter material-2 prepared in this example to intercept PMs: Sandwich a layer of low-pressure-drop particulate filter material-2 between two H-shaped bottles. The two H-shaped bottles are respectively connected to the air flow outlet and air flow inlet of the vacuum pump. Place a burning incense stick in the H-shaped bottle connected to the air flow outlet, and then connect two particle counters to each H-shaped bottle to measure the interception efficiency of the low-pressure-drop particulate filter material-2 for PMs. In addition, a differential pressure gauge is connected between the two H-shaped bottles to detect the pressure drop of the low-pressure-drop particulate filter material-2 when intercepting PMs. At a wind speed of 5.1 m s -1 When, the low-pressure-drop particulate filter material-2 for PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10 The interception efficiencies are 99.53%, 99.56%, 99.67%, 99.23%, 99.46% and 99.47% respectively (as shown in Figure 5 , the abscissa is the diameter of PMs), the corresponding pressure drop is 50 Pa, and the corresponding mass factors are 0.107, 0.108, 0.114, 0.097, 0.104 and 0.105 respectively (as shown in Figure 6 , the abscissa is the diameter of PMs).

[0022] Example 3 (1) Prepare a low-pressure-drop particulate filter material: Add 4.0 g of collagen fiber (chrome tanned) and 0.4 g of sodium carboxymethylcellulose to 135 mL of deionized water, stir at 30 °C and 320 rpm for 3.0 h, and freeze the obtained mixture at -45 o C for 4.0 h, and freeze-dry at -45 o C for 72 h to obtain the low-pressure-drop particulate filter material-3.

[0023] (2) Use the low-pressure-drop particulate filter material-3 prepared in this example to intercept PMs: Sandwich a layer of low-pressure-drop particulate filter material-3 between two H-shaped bottles. The two H-shaped bottles are respectively connected to the air flow outlet and air flow inlet of the vacuum pump. Place a burning incense stick in the H-shaped bottle connected to the air flow outlet, and then connect two particle counters to each H-shaped bottle to measure the interception efficiency of the low-pressure-drop particulate filter material-3 for PMs. In addition, a differential pressure gauge is connected between the two H-shaped bottles to detect the pressure drop of the low-pressure-drop particulate filter material-3 when intercepting PMs. At a wind speed of 5.1 m s -1 When, the low-pressure-drop particulate filter material-3 for PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM5.0 and PM 10 The interception efficiencies for Figure 7 are 78.66%, 92.85%, 94.61%, 96.21%, 86.43% and 93.54% respectively (as shown in Figure 8 , with the abscissa being the diameter of PMs), the corresponding pressure drop is 30 Pa, and the corresponding mass factors are 0.052, 0.088, 0.097, 0.109, 0.067 and 0.091 respectively (as shown in

[0024] Example 4 (1) Preparation of low-pressure-drop particulate filter material: Immerse 10.0 g of collagen fiber (chrome-tanned) in 300 mL of deionized water for 12 h, then add 100 mL of metal salt solutions (0.1 mol zirconium salt solution, 0.1 mol iron salt solution and 0.1 mol titanium salt solution) respectively, and adjust the pH to 2.0. Stir and react at 30 o °C for 4.0 h. Subsequently, adjust the pH of the reaction system to 4.0, react at 40 o °C for 4.0 h, filter through a 200-mesh gauze, wash with deionized water and absolute ethanol, and dry at 50 o °C to obtain the collagen fiber (chrome-tanned) treated with zirconium salt solution, iron salt solution and titanium salt solution.

[0025] Add 5.0 g of the collagen fiber (chrome-tanned) treated with zirconium salt solution, iron salt solution and titanium salt solution to 150 mL of deionized aqueous solution containing 0.5 g of sodium carboxymethylcellulose respectively, and stir at 30 o °C and 500 rpm for 3.0 h. Freeze the above mixture at -45 o °C for 4.0 h, and freeze-dry at -45 o °C for 72 h to obtain low-pressure-drop particulate filter material -4, low-pressure-drop particulate filter material -5 and low-pressure-drop particulate filter material -6 respectively. Figure 9 (a) is the prepared low-pressure-drop particulate filter material -4, Figure 9 (b) is the low-pressure-drop particulate filter material -5 and Figure 9 (c) is the photo of the low-pressure-drop particulate filter material -6. It can be seen from Figure 9 that the low-pressure-drop particulate filter material prepared by the present invention has a fluffy three-dimensional multi-layer structure.

[0026] Example 5 (1) Low-pressure-drop particulate filter material: Immerse 10.0 g of collagen fiber (chrome-tanned) in 300 mL of deionized water for 12 h, add 1.0 g of myricetin tannin to the above mixed system, and at 30o Stir the reaction for 4.0 h at C and 500 rpm. After the reaction, filter through a 200-mesh gauze and wash with deionized water and absolute ethanol, and dry at 50 o C. Add 5.0 g of the intermediate product prepared above to 150 mL of an aqueous solution containing 0.5 g of sodium carboxymethylcellulose, and stir at 30 o C and 500 rpm for 3.0 h. Freeze the above mixture at -45 o C for 4.0 h, and freeze-dry at -45 o C for 72 h to obtain the low-pressure-drop particulate filter material -7. Figure 10 It is a photograph of the low-pressure-drop particulate filter material -7.

[0027] Example 6 (1) Low-pressure-drop particulate filter material: Add 5.0 g of collagen fiber (chrome-tanned) to 150 mL of an aqueous solution containing 0.5 g of sodium carboxymethylcellulose, then add 3.0 g of activated carbon, and stir the reaction at 30 o C and 500 rpm for 3.0 h. Freeze the above mixture at -45 o C for 4.0 h, and freeze-dry at -45 o C for 72 h to obtain the low-pressure-drop particulate filter material -8. Figure 11 It is a photograph of the low-pressure-drop particulate filter material -8.

[0028] Comparative Example 1 (1) Use commercial filter materials (F7, G4, F5, and H10) to intercept PMs: Sandwich a layer of commercial filter material (F7, G4, F5, and H10) between two H-shaped bottles, and connect the air flow outlets and inlets of the vacuum pump to the two H-shaped bottles respectively. Place a burning incense stick in the H-shaped bottle connected to the air flow outlet, and then connect two particle counters to each H-shaped bottle to measure the interception efficiency of the commercial filter material for PMs. In addition, connect a differential pressure gauge between the two H-shaped bottles to detect the pressure drop of the commercial filter material for intercepting PMs. As Figure 12 and Figure 13 shown, at a wind speed of 5.1 m s -1 , the F7 commercial filter material for PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10The interception efficiencies are 47.35%, 54.05%, 56.90%, 59.47%, 62.13% and 62.16% respectively, the corresponding pressure drops are 170 Pa, and the corresponding quality factors are 0.004, 0.005, 0.005, 0.005, 0.006 and 0.006. At a wind speed of 5.1 m s -1 When, the G4 commercial filter material for PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10 The interception efficiencies are 70.15%, 83.16%, 92.55%, 91.69%, 82.21% and 54.02% respectively, the corresponding pressure drops are 130 Pa, and the corresponding quality factors are 0.009, 0.014, 0.020, 0.019, 0.013 and 0.006. At a wind speed of 5.1 m s -1 When, the F5 commercial filter material for PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10 The interception efficiencies are 83.59%, 88.92%, 95.72%, 97.83%, 97.22% and 99.37% respectively, the corresponding pressure drops are 125 Pa, and the corresponding quality factors are 0.014, 0.018, 0.025, 0.031, 0.029 and 0.041. At a wind speed of 5.1 m s -1 When, the H10 commercial filter material for PM 0.3 , PM 0.5 , PM 1.0 , PM 2.5 , PM 5.0 and PM 10 The interception efficiencies are 62.549%, 98.12%, 92.67%, 94.73%, 95.34% and 91.59% respectively, the corresponding pressure drops are 285 Pa, and the corresponding quality factors are 0.003, 0.014, 0.009, 0.010, 0.011 and 0.009.

[0029] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A low pressure drop particulate filter material, characterized in that: A material with a fluffy three-dimensional multi-layered structure formed by collagen self-assembly.

2. The low pressure drop particulate filter material according to claim 1, characterized in that: The collagen is collagen fiber or collagen fiber modified by metal organic framework material, zirconium salt, iron salt, titanium salt, tannin and activated carbon.

3. The method for preparing a low pressure drop particulate filter material according to claim 1 or 2, characterized in that: Controllable and autonomous loading of collagen.

4. Use of the low pressure drop particulate filter material as claimed in claim 1 or 2 in filtering particulate matter.

5. The use according to claim 4, characterized in that The particulate matter includes PM 0.3 、PM 0.5 、PM 1.0 、PM 2.5 、PM 5.0 、PM 10 Any one or more of them can achieve simultaneous and long-term interception of multiple particulate matter.

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