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

Abstract

The invention belongs to the field of nanofiber materials, and particularly relates to a preparation method of a moisture-proof nanofiber material for filtering dust and removing CO. The method comprises the following steps: S1, mixing Mn (CH3COO) 2.4 H2O and Cu (NO3) 2.3 H2O to obtain a mixed solution I; s2, adding a Sn source into the mixed solution I, and adding a KMnO4 aqueous solution until the solution is dark purple; s3, filtering the mixed solution II, and washing the precipitate I to remove anions so as to obtain a precipitate II; s4, the precipitate II is dried and then subjected to high-temperature calcination, and copper-manganese-tin oxide is obtained; s5, dissolving the copper-manganese-tin oxide and PVDF (Polyvinylidene Fluoride) in a DMF (Dimethyl Formamide) solvent; s6, the mixed solution III is poured into an injector for spinning, and the moisture-proof nanofiber material is obtained after drying. According to the embodiment of the invention, the fiber membrane loaded with the copper-manganese-tin oxide can achieve the effect of separating CO while achieving a good dust filtering effect, and has certain moisture resistance at the same time.

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] The conditions of coal mining are complex, the working environment of operators is relatively poor, and there are a lot of dust, harmful gases, physical and noise hazards in the mining process. Among them, dust hazards are the most serious. Mining operators will absorb a lot of dust and harmful substances during long-term operations, which is prone to pneumoconiosis. In 2023, there were 27,240 new cases of occupational diseases, including 23,812 cases of pneumoconiosis, accounting for as much as 87.4%. Now workers are facing the hazards of pneumoconiosis, including various exposure to dust, toxic chemicals, radioactive substances, etc. The most common and serious pneumoconiosis are coal workers' pneumoconiosis and silicosis, and the number of coal workers' pneumoconiosis can account for more than half of pneumoconiosis patients. At present, there are a large number of people employed in the coal industry, and the mining conditions are complex. There are many occupational safety hazards. Timely deployment and correct use of personal protective equipment are particularly important for ensuring the safety and health of the majority of coal workers. Dust hazards are the most serious occupational hazards in the coal industry, followed by toxic and harmful gas hazards. Dust protection for coal miners can be considered from two aspects. First, reduce or eliminate the harm of coal mine dust to workers from the perspective of engineering technology; however, due to various factors such as enterprise cost and technical capabilities, when engineering technology cannot completely eliminate the harm of dust, it is necessary to consider equipping coal miners with respiratory protection equipment. This method has now become an important means to protect the health of coal miners. Therefore, it is particularly important to prepare an individual protective material with good dust filtration effect and toxic and harmful gas separation.

[0003] With the development of nanotechnology, electrospinning, as a simple and effective new processing technology for producing nanofibers, plays a huge role in the fields of filtration and protection, catalysis, energy, etc. In addition to its small diameter, electrospun fibers also have the advantages of small pore size, high porosity, and good fiber uniformity, which makes them show great application potential in the fields of gas filtration, liquid filtration, and personal protection. Therefore, electrospinning technology is used as the main method for preparing individual dust protection materials.

[0004] Electrospinning technology is a method that uses high-voltage electrostatic field forces to stretch polymer solutions or melts into nanofibers. In a typical electrospinning process, the polymer solution is loaded into a syringe and formed into droplets through a needle. Then, under the action of high voltage, the droplets overcome surface tension to form a jet. As the solvent evaporates, the jet solidifies to form nanofibers, which are eventually 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. It is widely used in filter materials, biomedical materials, sensors and other fields.

[0005] CO is the most common and dangerous gas among the toxic and harmful gases in mines. 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, such as loaded precious metals or transition metal oxides, are known to 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 purpose, the embodiment of the present invention provides the following technical solutions:

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

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

[0010] S2, adding Sn source to the mixed solution I, and adding KMnO4 aqueous solution while stirring until the solution is dark purple, to obtain a mixed solution II;

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

[0012] S4, drying the precipitate II and 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, 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 process of adding the KMnO4 aqueous solution, the shaking speed varies from 20-120 rpm, the shaking time varies from 30 to 180 min, the temperature varies from 25°C to 50°C, and the pH varies 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 a good dust filtration effect while achieving the effect of separating CO and having 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 achieves the best performance of dust filtration and CO separation in a high humidity environment at the same time as much as possible.

[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) The embodiment of the present invention selects copper manganese tin oxide as a CO removal agent, thereby reducing 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 prepared fibers can reach the nanometer level, have the advantages of 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 of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

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

[0032] Figure 2 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 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 effect of the fiber membrane's anti-watering 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 Graph showing the filtration efficiency under wet conditions in a typical embodiment of the present invention. DETAILED DESCRIPTION

[0039] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0040] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0041] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0042] The 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, Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O are mixed to obtain a mixed solution I;

[0044] S2, adding Sn source to the mixed solution I, and adding KMnO4 aqueous solution while stirring until the solution is dark purple, to obtain a mixed solution II;

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

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

[0047] S5, dissolving the copper manganese tin oxide and PVDF in a 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 in conjunction with 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 Sn source to the mixed solution I, and add KMnO4 aqueous solution while stirring until the solution is dark purple, to obtain mixed solution II; the Sn source includes SnCl4 solution, but is not limited thereto. The mass percentage of Sn in the SnCl4 solution in the mixed solution I is 8.5wt%. During the addition of KMnO4 aqueous solution, the shaking speed varies from 20-120rpm, the shaking time varies from 30 to 180min, the temperature varies from 25°C to 50°C, and the pH varies from 4 to 12.

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

[0055] S4, the precipitate II is dried at 110° C. for 24 hours, and calcined 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, stir evenly, and obtain a mixed solution III; the mass percentage of the PVDF is 15wt%.

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

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

[0063] S4, the precipitate II is dried at 100° C. for 26 hours, and calcined 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, stir evenly, and 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 Sn source to the mixed solution I, and add KMnO4 aqueous solution while stirring until the solution is dark purple, to obtain mixed solution II; the Sn source includes SnCl4 solution, but is not limited thereto. The mass percentage of Sn in the SnCl4 solution in the mixed solution I is 9wt%. During the addition of KMnO4 aqueous solution, the shaking speed varies from 20-120rpm, the shaking time varies from 30 to 180min, the temperature varies from 25°C to 50°C, and the pH varies from 4 to 12.

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

[0071] S4, the precipitate II is dried at 120° C. for 22 hours, and calcined 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, stir evenly, and 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] The CO performance test was carried out on a BSD-Chem C200 fully automatic chemisorption instrument. All data were collected at 2 °C 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, and the flow rate is 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, allowing about 5% water vapor to enter the reaction feed.

[0076] Test results such as Figure 7 and 8 shown.

[0077] Experiment 2

[0078] The filtration performance test of the fiber membrane was carried out on the LZC-K1 filter material comprehensive performance test bench. The fiber membrane filtration performance test was carried out with a non-woven fabric test. 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, Mn(CH3COO)2·4H2O and Cu(NO3)2·3H2O are mixed to obtain a mixed solution I; S2, adding Sn source to the mixed solution I, and adding KMnO4 aqueous solution while stirring until the solution is dark purple, to obtain a mixed solution II; S3, filtering the mixed solution II, collecting the precipitate I, washing the precipitate I to remove anions, and obtaining the precipitate II; S4, drying the precipitate II and calcining it at high temperature to obtain copper manganese tin oxide; S5, dissolving the copper manganese tin oxide and PVDF in a 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 mass ratio of Mn(CH3COO)2·4H2O to Cu(NO3)2·3H2O is 25-45:55-75.

3. 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.

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

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 S2, during the process of adding the KMnO4 aqueous solution, the shaking speed varies from 20-120 rpm, the shaking time varies from 30 to 180 min, the temperature varies from 25°C to 50°C, and the pH varies from 4 to 12.

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 S4, the precipitate II is dried at 100-120° C. for 22-26 hours.

7. 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 calcined at 280-350° C. for 2-2.5 hours to obtain the copper manganese tin oxide.

8. 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 %.

9. 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.

10. Use of the moisture-resistant nanofiber material prepared by the method according to any one of claims 1 to 9 in filtering dust and removing CO.

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