Preparation method of moisture-resistant nanofiber material for filtering dust and removing CO

Abstract

The present invention belongs to the field of nanofiber materials, and in particular relates to a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO. The method comprises: S1. mixing Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O to obtain a mixed solution I; S2. adding a Sn source and a KMnO4 aqueous solution to the mixed solution I until the solution turns dark purple; S3. filtering the mixed solution II and washing the precipitate I to remove anions, thereby obtaining a precipitate II; S4. drying the precipitate II and then calcining it at a high temperature to obtain copper-manganese-tin oxide; S5. dissolving the copper-manganese-tin oxide and polyvinyldifluoromethane (PVDF) in a DMF solvent; S6. pouring the mixed solution III into a syringe for spinning, and drying to obtain the moisture-resistant nanofiber material. The invention of the copper-manganese-tin oxide-loaded fiber membrane in this embodiment of the present invention not only achieves excellent dust filtration, but also can separate CO and possesses a certain degree of moisture resistance.

Description

Technical Field

[0001] The invention belongs to the field of nanofiber materials, and in particular relates to a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO. Background Art

[0002] Coal mining is a complex process, creating a harsh working environment for workers. Underground mining is subject to significant dust, harmful gases, physical hazards, and noise. Dust is the most severe hazard, and workers absorb large amounts of dust and harmful substances during long-term work, making them susceptible to pneumoconiosis. In 2023, there were 27,240 new cases of occupational diseases, of which 23,812 were pneumoconiosis, accounting for a staggering 87.4%. Workers are currently exposed to the hazards of pneumoconiosis, including exposure to various dust, toxic chemicals, and radioactive materials. The most common and severe forms of pneumoconiosis are coal miners' pneumoconiosis and silicosis, which account for over half of all pneumoconiosis cases. The coal industry employs a large number of people, and mining conditions are complex, with multiple occupational safety hazards coexisting. The timely and proper use of personal protective equipment is crucial for ensuring the safety and health of coal miners. Dust is the most serious occupational hazard in the coal industry, followed by toxic and harmful gases. Dust protection for coal miners can be considered from two perspectives. First, the harm of coal mine dust to workers can be reduced or eliminated through engineering technology. However, due to various factors such as enterprise cost and technical capabilities, when engineering technology cannot completely eliminate the dust hazard, it is necessary to consider equipping coal miners with respiratory protection equipment. This method has become an important means to protect coal miners' health. Therefore, it is particularly important to develop a personal protective material with excellent dust filtration and toxic and harmful gas separation.

[0003] With the development of nanotechnology, electrospinning, a simple and effective new processing technology for producing nanofibers, has played a significant role in fields such as filtration and protection, catalysis, and energy. In addition to its small diameter, electrospun fibers also possess advantages such as small pore size, high porosity, and excellent fiber uniformity, showing great potential for application in gas filtration, liquid filtration, and personal protection. Therefore, electrospinning technology has been adopted as the primary method for preparing personal dust protection materials.

[0004] Electrospinning is a method that uses high-voltage electrostatic fields to stretch polymer solutions or melts into nanofibers. In a typical electrospinning process, a polymer solution is loaded into a syringe and passed through a needle to form droplets. Then, under the action of a high voltage, the droplets overcome surface tension to form a jet. As the solvent evaporates, the jet solidifies into nanofibers, which are ultimately deposited on a collection device to form a fiber membrane. This technology can produce fibers with diameters ranging from tens of nanometers to several microns, with characteristics such as large specific surface area, high porosity, and uniform fiber diameter. They are widely used in filter materials, biomedical materials, and sensors.

[0005] Among the toxic and harmful gases in mines, CO is the most common and dangerous gas. The established method for removing carbon monoxide from breathing air is to equip personal protective materials with an active substance to produce adsorptive or reactive carbon monoxide removal. Many catalytically active components are known, such as loaded precious metals or transition metal oxides, which can remove carbon monoxide by catalytic oxidation with atmospheric oxygen at room temperature. Copper manganese oxide is a well-known carbon monoxide catalyst. However, a major disadvantage of copper manganese oxides is their weak stability to water vapor, which is inevitably contained in breathing air and adsorbs on the surface of copper manganese oxide more strongly than carbon monoxide, thereby reducing its catalytic performance. Therefore, improving the moisture resistance of copper manganese oxide in breathing materials is an important way to solve the CO problem. Summary of the Invention

[0006] In order to solve the above problems, the object of the present invention is to provide a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO.

[0007] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0008] According to a first aspect of an embodiment of the present invention, a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO is provided, comprising the following steps:

[0009] S1, mixing Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O to obtain mixed solution I;

[0010] S2. Add Sn source to the mixed solution I, and add KMnO4 aqueous solution while stirring until the solution turns dark purple to obtain mixed solution II;

[0011] S3, filtering the mixed solution II, collecting the precipitate I, and washing the precipitate I to remove anions to obtain a precipitate II;

[0012] S4, drying the precipitate II and then calcining it at high temperature to obtain copper manganese tin oxide;

[0013] S5, dissolving the copper manganese tin oxide and PVDF (polyvinylidene fluoride) in DMF (N,N-dimethylformamide) solvent, and stirring evenly to obtain a mixed solution III;

[0014] S6. Pour the mixed solution III into a syringe for spinning to obtain a spinning material, and dry the spinning material to obtain the moisture-resistant nanofiber material.

[0015] Furthermore, the mass ratio of Mn(CH3COO)2·4H2O to Cu(NO3)2·3H2O is 25-45:55-75, preferably 33:67.

[0016] Furthermore, the Sn source includes a SnCl4 solution.

[0017] Furthermore, the mass percentage of Sn in the SnCl4 solution in the mixed solution I is 7-9wt%, preferably 8.5wt%.

[0018] Furthermore, in step S2, during the addition of the KMnO4 aqueous solution, the shaking speed was varied from 20-120 rpm, the shaking time was varied from 30 to 180 min, the temperature was varied from 25°C to 50°C, and the pH was varied from 4 to 12.

[0019] Furthermore, in step S4, the precipitate II is dried at 100-120° C. for 22-26 hours, preferably at 110° C. for 24 hours.

[0020] Furthermore, in step S4, the precipitate II is calcined at 300° C. for 2 hours to obtain the copper manganese tin oxide.

[0021] Furthermore, in step S5, the mass percentage of the PVDF is 12-18 wt%.

[0022] Furthermore, in step S6, the spinning material is dried at a temperature of 45-60°C.

[0023] According to a second aspect of an embodiment of the present invention, there is provided a use of a moisture-resistant nanofiber material prepared by the above method in filtering dust and removing CO.

[0024] Compared with the prior art, the advantages of the embodiments of the present invention are:

[0025] (1) The invention of the fiber membrane loaded with copper manganese tin oxide in the embodiment of the present invention can achieve the function of separating CO while achieving good dust filtration effect, and at the same time has a certain moisture resistance, which provides a new idea for individual dust protection materials in coal mines.

[0026] (2) The embodiment of the present invention uses the oxide concentration gradient method to screen and obtain the optimal loading amount with good dust filtration effect, high CO separation performance, and strong moisture resistance, and maximizes the possibility of achieving the optimal performance of dust filtration and CO separation in a high humidity environment.

[0027] (3) In the embodiment of the present invention, tin oxide is added to make the nanofiber membrane have good moisture resistance in a mine environment.

[0028] (4) In the embodiment of the present invention, copper manganese tin oxide is selected as the CO removal agent, which reduces the product cost.

[0029] (5) The experimental device of the electrospinning method of the embodiment of the present invention is relatively simple and easy to build, and the fibers prepared can reach the nanometer level, have the advantages of a large aspect ratio, high porosity, good uniformity and can reach the nanometer level. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0031] Figure 1 This is an EDS diagram of a fiber membrane in a typical embodiment of the present invention;

[0032] Figure 2 This is a SEM image of a fiber membrane in a typical embodiment of the present invention;

[0033] Figure 3 is the fiber membrane diameter distribution in a typical embodiment of the present invention;

[0034] Figure 4 This is an AFM image of a fiber membrane in a typical embodiment of the present invention;

[0035] Figure 5 This is a diagram showing the anti-water effect of the fiber membrane in a typical embodiment of the present invention;

[0036] Figure 6 is a graph showing the filtration efficiency of a fiber membrane for sodium chloride aerosol in a typical embodiment of the present invention;

[0037] Figure 7 is a graph of CO filtration efficiency in a typical embodiment of the present invention;

[0038] Figure 8 is a diagram of filtration efficiency under humid conditions in a typical embodiment of the present invention. DETAILED DESCRIPTION

[0039] In view of the shortcomings of the prior art, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of the present invention. The following will further explain this technical solution, its implementation process and principles.

[0040] The present invention will be further described in detail below in conjunction with specific embodiments. The examples provided are only for illustrating the present invention and are not intended to limit the scope of the present invention. The examples provided below can serve as a guide for further improvements by those skilled in the art and are not intended to limit the present invention in any way.

[0041] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0042] An embodiment of the present invention provides a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO, comprising the following steps:

[0043] S1, mixing Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O to obtain a mixed solution I;

[0044] S2. Add Sn source to the mixed solution I, and add KMnO4 aqueous solution while stirring until the solution turns dark purple to obtain mixed solution II;

[0045] S3, filtering the mixed solution II, collecting the precipitate I, and washing the precipitate I to remove anions to obtain a precipitate II;

[0046] S4, drying the precipitate II and then calcining it at high temperature to obtain copper manganese tin oxide;

[0047] S5, dissolving the copper manganese tin oxide and PVDF in DMF solvent, stirring evenly, to obtain a mixed solution III;

[0048] S6. Pour the mixed solution III into a syringe for spinning to obtain a spinning material, and dry the spinning material to obtain the moisture-resistant nanofiber material.

[0049] In order to better understand the technical solution of the present invention, it is described in detail below with reference to specific embodiments.

[0050] Example 1

[0051] This embodiment provides a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO, comprising the following steps:

[0052] S1. Mix Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O to obtain a mixed solution I; the mass ratio of Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O is 33:67.

[0053] S2. Add a Sn source to the mixed solution I and, while stirring, add a KMnO4 aqueous solution until the solution turns dark purple, thereby obtaining a mixed solution II. The Sn source includes, but is not limited to, a SnCl4 solution. The mass percentage of Sn in the SnCl4 solution relative to the mixed solution I is 8.5 wt%. During the addition of the KMnO4 aqueous solution, the shaking speed is varied from 20-120 rpm, the shaking time is varied from 30 to 180 minutes, the temperature is varied from 25°C to 50°C, and the pH is varied from 4 to 12.

[0054] S3, filtering the mixed solution II, collecting the precipitate I, and washing the precipitate I to remove anions to obtain a precipitate II;

[0055] S4, drying the precipitate II at 110° C. for 24 hours, and calcining at 300° C. for 2 hours to obtain copper manganese tin oxide;

[0056] S5. Dissolve the copper manganese tin oxide and PVDF in DMF solvent and stir evenly to obtain a mixed solution III; the mass percentage of the PVDF is 15 wt%.

[0057] S6. Pour the mixed solution III into a syringe for spinning to obtain a spinning material, and dry the spinning material at a temperature of 50° C. to obtain the moisture-resistant nanofiber material.

[0058] Example 2

[0059] This embodiment provides a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO, comprising the following steps:

[0060] S1. Mix Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O to obtain a mixed solution I; the mass ratio of Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O is 25:75.

[0061] S2. Add a Sn source to the mixed solution I and, while stirring, add a KMnO4 aqueous solution until the solution turns dark purple, to obtain a mixed solution II. The Sn source includes, but is not limited to, a SnCl4 solution. The mass percentage of Sn in the SnCl4 solution relative to the mixed solution I is 7 wt%. During the addition of the KMnO4 aqueous solution, the shaking speed is varied from 20-120 rpm, the shaking time is varied from 30 to 180 minutes, the temperature is varied from 25°C to 50°C, and the pH is varied from 4 to 12.

[0062] S3, filtering the mixed solution II, collecting the precipitate I, and washing the precipitate I to remove anions to obtain a precipitate II;

[0063] S4, drying the precipitate II at 100° C. for 26 hours, and calcining at 280° C. for 2.5 hours to obtain copper manganese tin oxide;

[0064] S5. Dissolve the copper manganese tin oxide and PVDF in DMF solvent and stir evenly to obtain a mixed solution III; the mass percentage of the PVDF is 12 wt%.

[0065] S6. Pour the mixed solution III into a syringe for spinning to obtain a spinning material, and dry the spinning material at a temperature of 45° C. to obtain the moisture-resistant nanofiber material.

[0066] Example 3

[0067] This embodiment provides a method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO, comprising the following steps:

[0068] S1. Mix Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O to obtain a mixed solution I; the mass ratio of Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O is 45:55.

[0069] S2. Add a Sn source to the mixed solution I and, while stirring, add a KMnO4 aqueous solution until the solution turns dark purple, to obtain a mixed solution II. The Sn source includes, but is not limited to, a SnCl4 solution. The mass percentage of Sn in the SnCl4 solution relative to the mixed solution I is 9 wt%. During the addition of the KMnO4 aqueous solution, the shaking speed is varied from 20-120 rpm, the shaking time is varied from 30 to 180 minutes, the temperature is varied from 25°C to 50°C, and the pH is varied from 4 to 12.

[0070] S3, filtering the mixed solution II, collecting the precipitate I, and washing the precipitate I to remove anions to obtain a precipitate II;

[0071] S4, drying the precipitate II at 120° C. for 22 hours, and calcining at 350° C. for 2 hours to obtain copper manganese tin oxide;

[0072] S5. Dissolve the copper manganese tin oxide and PVDF in DMF solvent and stir evenly to obtain a mixed solution III; the mass percentage of the PVDF is 18 wt%.

[0073] S6. Pour the mixed solution III into a syringe for spinning to obtain a spinning material, and dry the spinning material at a temperature of 60° C. to obtain the moisture-resistant nanofiber material.

[0074] Experiment 1

[0075] CO performance test was carried out on BSD-Chem C200 fully automatic chemisorption instrument. All data were collected at 2℃·min -1 The heating rate is used to raise the temperature to the target temperature for collection. The volume composition of the raw gas is 1% CO, 21% O2 and high purity N2 in balance, with a flow rate of 30 mL min -1 For the moisture resistance test, the reactant feed was passed through a water bubbler controlled at 25°C before entering the reactor, so that about 5% water vapor entered the reaction feed.

[0076] The test results are as follows Figure 7 and 8 shown.

[0077] Experiment 2

[0078] The fiber membrane filtration performance test was conducted on the LZC-K1 filter material comprehensive performance test bench. The fiber membrane filtration performance test was conducted with non-woven fabric. During the test, electrically neutral NaCl aerosol particles were atomized by an air pump. The average particle size was 0.3-0.5μm, and the particle size standard deviation was 1.86. The NaCl aerosol particles passed through the effective test area of ​​100cm from the upstream. 2 The fiber membrane with non-woven fabric enters the downstream, and the upstream and downstream aerosol particle concentration values ​​are detected by a laser ion counter. The resistance pressure drop of the fiber membrane and the system flow are measured by a high-sensitivity electronic pressure sensor. During the test, the air flow rate is 32L / min, the ambient temperature is 23-27℃, and the humidity is 40-50%.

[0079] The embodiments described above are only for illustrating the preferred implementation of the present invention. It should be pointed out that for ordinary technicians in this field, several improvements can be made without departing from the scope of protection of this patent, and these improvements should also be regarded as within the scope of protection of this patent.

Claims

1. A method for preparing a moisture-resistant nanofiber material for filtering dust and removing CO, characterized in that: The following steps are involved: S1. Mix Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O to obtain a mixed solution I; the mass ratio of Mn(CH3COO)2·4H2O to Cu(NO3)2·3H2O is 25-45:55-75; S2. Adding a Sn source to the mixed solution I, and adding a KMnO4 aqueous solution while stirring until the solution turns dark purple, to obtain a mixed solution II; during the addition of the KMnO4 aqueous solution, the shaking speed is changed from 20 to 120 rpm, the shaking time is changed from 30 to 180 min, the temperature is changed from 25° C. to 50° C., and the pH is changed from 4 to 12; S3, filtering the mixed solution II, collecting the precipitate I, and washing the precipitate I to remove anions to obtain a precipitate II; S4, drying the precipitate II and then calcining it at high temperature to obtain copper manganese tin oxide; calcining the precipitate II at 280-350° C. for 2-2.5 hours to obtain the copper manganese tin oxide; S5, dissolving the copper manganese tin oxide and PVDF in DMF solvent, stirring evenly, to obtain a mixed solution III; S6. Pour the mixed solution III into a syringe for spinning to obtain a spinning material, and dry the spinning material to obtain the moisture-resistant nanofiber material.

2. The method for preparing the moisture-resistant nanofiber material for filtering dust and removing CO according to claim 1, characterized in that: The Sn source includes a SnCl4 solution.

3. The method for preparing the moisture-resistant nanofiber material for filtering dust and removing CO according to claim 2, characterized in that: The mass percentage of Sn in the SnCl4 solution in the mixed solution I is 7-9 wt%.

4. The method for preparing the moisture-resistant nanofiber material for filtering dust and removing CO according to claim 1, characterized in that: In step S4, the precipitate II is dried at 100-120° C. for 22-26 hours.

5. The method for preparing the moisture-resistant nanofiber material for filtering dust and removing CO according to claim 1, characterized in that: In step S5, the mass percentage of the PVDF is 12-18 wt%.

6. The method for preparing the moisture-resistant nanofiber material for filtering dust and removing CO according to claim 1, characterized in that: In step S6, the spinning material is dried at a temperature of 45-60°C.

7. Use of the moisture-resistant nanofiber material prepared by the method according to any one of claims 1 to 6 in filtering dust and removing CO.

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