Modified carbon fiber mask capable of degrading ozone

Abstract

The invention provides a modified carbon fiber mask capable of degrading ozone, and belongs to the technical field of protective articles. The preparation method comprises the following steps: soaking a carbon fiber mesh in a mixed solution of sulfuric acid and hydrogen peroxide for pretreatment to obtain a carbon fiber precursor 1; dipping the carbon fiber precursor 1 in a ferric salt solution, and then drying and calcining to obtain a precursor 2; and dipping the precursor 2 in a silver salt solution, and then drying and calcining to obtain the modified carbon fiber. According to the preparation method, the carbon fibers are pressed into the 1-2mm mesh, then the carbon fiber mesh is modified by adopting the preparation method to obtain the modified carbon fiber mesh, and the modified carbon fiber mesh is used as a functional layer of the mask, so that ozone can be quickly decomposed into oxygen, the mask has more lasting ozone degradation capability, and the effective service time of the mask can be prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of protective equipment, and in particular to an ozone-degradable modified carbon fiber mask. Background Art

[0002] Ozone concentration is one of the 31 indoor air control parameters. In addition to outdoor air, the sources of ozone in indoor air are mostly primary sources, such as computers, printers, ozone disinfection cabinets, electrostatic purifiers, etc., which can be effectively controlled by air purifiers with additional ultraviolet light, catalytic nets, and plant planting. In the outdoor environment, ozone is mostly secondary sources, that is, produced by photochemical reactions. The method of controlling the reactants of photochemical reactions to control the product ozone is difficult to be effective due to meteorological conditions, randomness and uncontrollability of human emissions. Although the population exposed to the ambient atmosphere still has a low average risk of ozone exposure, ozone ranks in the top three in terms of health risk value among ambient air pollutants, making it the most dangerous air pollutant that can be monitored. At present, the control of ambient atmospheric ozone is through monitoring alarms and dispatching fog cannons for regional reduction. The bio-enzyme mist produced by fog cannons can consume ozone, but this method depends on the accuracy of the monitoring system and is limited by the equipment of mobile devices. Emission reduction and control of atmospheric ozone precursors NOx and VOCs is still the main method of atmospheric ozone control.

[0003] People who exercise early in the morning have a higher risk of ozone exposure. This is because, firstly, the areas where early exercise occurs are mostly high-density areas of natural source emissions of VOCs. Secondly, the high concentration of NOx emissions caused by the morning rush hour makes the early exercise square a NOx gathering center. As the sun rises, the ultraviolet light gradually becomes stronger, allowing the photochemical reaction to proceed rapidly, and the concentration of its main product, ozone, increases accordingly. The early exercise population is mainly middle-aged and elderly people, and their exercise gas flux is about 15-20L / min, which is 2-3 times that of sedentary adults. Data show that in recent years, pulmonary infarction has become one of the main causes of sudden death in the elderly, and ozone is an important risk factor for chronic obstructive pulmonary disease (COPD). The key to preventing COPD is to reduce the risk of ozone exposure. In weather with severe ozone pollution, outdoor activities should be minimized, especially for people with respiratory diseases. However, ozone pollution is deceptive, because low-concentration ozone has a fresh, grassy smell, which leads to people's current inability to recognize the existence of ozone pollution. The sensitivity of the atmospheric monitoring and early warning system is limited by the atmospheric ozone standard, and the real-time performance cannot be well achieved, which also exacerbates people's lack of awareness of the gas they breathe. Wear a protective mask when exercising in the early morning to reduce the inhalation of ozone.

[0004] Currently, the main protective masks on the market are non-woven masks, activated carbon masks, and electronic masks. Non-woven masks are disposable masks that mainly use the interweaving of polyester and polyester fibers to block droplets and particulate matter, and at the same time block the bacteria and viruses attached thereto. Activated carbon masks utilize the adsorption of activated carbon on gaseous pollutants including ozone. However, as the use time increases, the adsorption sites of activated carbon will gradually be occupied, the adsorption capacity will gradually saturate, and the adsorption effect on ozone will decrease significantly, and it needs to be replaced in time, otherwise it may cause secondary release of ozone. Electronic masks usually need to be equipped with a battery or an external power supply to drive its purification device, such as a negative ion generator, a fan, etc. This type of mask is relatively large in size, which to a certain extent limits its flexibility and convenience in use and cannot be used normally in places without power supply. The above-mentioned masks have a certain ability to prevent and control polluted gases, mainly removing particulate matter and some harmful gases in the air through adsorption, filtration, etc., but no ozone prevention and control function has been seen. Summary of the Invention

[0005] Based on the above, the purpose of the present invention is to provide a modified carbon fiber mask for degrading ozone.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention, a preparation method of a modified carbon fiber for degrading ozone, includes the following steps:

[0008] Immerse carbon fiber in a mixed solution of sulfuric acid and hydrogen peroxide for pretreatment to obtain carbon fiber precursor 1;

[0009] Immerse the carbon fiber precursor 1 in an iron salt solution, then dry and calcine to obtain precursor 2;

[0010] Immerse the precursor 2 in a silver salt solution, then dry and calcine to obtain modified carbon fiber.

[0011] Another technical solution of the present invention, a modified carbon fiber prepared by the above preparation method.

[0012] Another technical solution of the present invention, an application of the above modified carbon fiber in degrading ozone in the air.

[0013] Another technical solution of the present invention, a modified carbon fiber mask for degrading ozone, includes a functional layer, and the preparation method of the functional layer is: first press carbon fiber with a diameter of 5-10 microns into a mesh with a thickness of 1-2 mm, and then modify the mesh by the above preparation method to obtain a modified carbon fiber mesh.

[0014] The present invention discloses the following technical effects:

[0015] (1) It can degrade ozone efficiently and stably: The modified carbon fiber of the present invention has a high specific surface area and abundant active sites, which can efficiently adsorb ozone molecules and rapidly decompose ozone into oxygen and carbon dioxide through its good catalytic activity.

[0016] (2) It is not easy to be inactivated: The modified carbon fiber of the present invention is not easy to be inactivated, has a more persistent ozone degradation ability, can extend the effective use time of the mask, and reduce the replacement frequency.

[0017] (3) The structure is simple and lightweight: Compared with electronic masks, etc., the present invention does not need to be equipped with complex electronic components such as negative ion generators, batteries, etc. The structure is relatively simple, the overall mass of the mask is lighter, it is more comfortable and lightweight to wear, and it is also convenient to carry and use, increasing the comfort level. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the ozone-degrading modified carbon fiber mask of the present invention. Detailed Embodiments

[0020] Now, various exemplary embodiments of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation methods of the present invention.

[0021] It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0022] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0023] Without departing from the scope or spirit of the present invention, various modifications and variations can be made to the specific embodiments of the description of the present invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.

[0024] Regarding the use of "comprising", "including", "having", "containing", etc. in this text, they are all open-ended terms, meaning including but not limited to.

[0025] The first aspect of the present invention provides a preparation method of ozone-degrading modified carbon fiber, comprising the following steps:

[0026] Impregnate carbon fiber in a mixed solution of sulfuric acid and hydrogen peroxide for pretreatment to obtain carbon fiber precursor 1;

[0027] Impregnate the carbon fiber precursor 1 in an iron salt solution, and then dry and calcine it to obtain precursor 2;

[0028] Impregnate the precursor 2 in a silver salt solution, and then dry and calcine it to obtain modified carbon fiber.

[0029] The present invention first treats carbon fiber with acid to make it have high surface activity and roughness, then ultrasonically impregnates and loads substances such as iron and silver, and then high-temperature dries and calcines the corresponding metal oxides as catalysts for the reaction of activated carbon with oxygen, and finally obtains modified carbon fiber. The modified carbon fiber prepared by the present invention has the abilities of antibacterial, adsorption, ozone molecule degradation and oxygen production.

[0030] In some embodiments of the present invention, the diameter of the carbon fiber is 5-10 microns.

[0031] In some embodiments of the present invention, before impregnating the carbon fiber in a mixed solution of sulfuric acid and hydrogen peroxide for pretreatment, it further includes the steps of washing and drying the carbon fiber.

[0032] In some embodiments of the present invention, the volume ratio of sulfuric acid to hydrogen peroxide is 1:1; the temperature of the pretreatment is 50-60°C, and the time is 5-15 min.

[0033] In some embodiments of the present invention, the iron salt solution is Fe(NO3)3 solution; the concentration of the Fe(NO3)3 solution is 0.2-0.5 mol / L; the silver salt solution is AgNO3 solution; the concentration of the AgNO3 solution is 0.02-0.05 mol / L.

[0034] In the present invention, in a lower solution concentration, the metal ion concentration is low, resulting in a small number of ions available for nucleation per unit volume, a relatively weak nucleation driving force, and a slow reaction rate. In a high-concentration solution, the impurity ion concentration also increases correspondingly, increasing the possibility of their co-precipitation with the target metal ions and easily mixing into the surface of the generated metal oxide, reducing the product purity.

[0035] In some embodiments of the present invention, the temperature of the impregnation is 40 - 60 °C, the time is 15 - 20 min; the impregnation method is ultrasonic impregnation; the power of the ultrasound is 240 W.

[0036] In some embodiments of the present invention, the parameters for drying are set as: holding at 200 °C for 2 h; the parameters for calcination are set as: holding at 400 °C for 2 h.

[0037] In the present invention, the specific pretreatment solution, specific treatment time, and temperature range are crucial for improving the surface activity and roughness of carbon fibers and are the basis for subsequent effective loading of metal oxides. By defining the types of specific metal oxide catalyst precursors, impregnation solution concentration, impregnation time, and temperature, etc., the prepared modified carbon fibers can efficiently decompose ozone and can decompose ozone during normal wearing without other limiting conditions.

[0038] The present invention does not make special limitations on the dosages of the above-mentioned mixed solution of sulfuric acid and hydrogen peroxide, iron salt solution, and silver salt solution, as long as the precursor can be completely impregnated.

[0039] The second aspect of the present invention provides a modified carbon fiber prepared by the above preparation method.

[0040] The third aspect of the present invention provides an application of the above-mentioned ozone-degrading modified carbon fiber in the degradation of ozone in the air.

[0041] The fourth aspect of the present invention provides an ozone-degrading modified carbon fiber mask, including a functional layer, and the preparation method of the functional layer is: first press carbon fibers with a diameter of 5 - 10 microns into a mesh with a thickness of 1 - 2 mm, and then modify the mesh by the above preparation method to obtain a modified carbon fiber mesh.

[0042] In some embodiments of the present invention, the ozone-degrading modified carbon fiber mask further includes a filter layer, a skin-friendly layer, a nose clip, and ear straps; both the filter layer and the skin-friendly layer are non-woven fabric layers; the functional layer is located between the filter layer and the skin-friendly layer.

[0043] Description of the structure of the ozone-degrading modified carbon fiber mask:

[0044] (1) Filter layer: Made of non-woven fabric. It can block larger particulate pollutants, droplets, etc., and at the same time has certain wear resistance and corrosion resistance to protect the internal structure of the mask.

[0045] (2) Functional layer: This is the core part of the mask and contains modified carbon fiber. The modified carbon fiber is obtained by pretreating the carbon fiber raw material to improve the surface activity and roughness, then loading metal oxides by the impregnation method, and drying and high-temperature calcination. When air passes through, ozone reacts with carbon under the catalyst to generate oxygen and carbon dioxide.

[0046] (3) Skin-friendly layer: Made of non-woven fabric. It is in direct contact with the wearer's face, has good comfort and hygroscopicity, can absorb the water vapor exhaled by the wearer, and improves the wearing comfort.

[0047] (4) Nose clip: Made of a shapeable metal strip. It is located at the upper part of the mask and can be adjusted according to the shape of the bridge of the nose during wearing to make the mask fit better with the face and prevent air leakage from the bridge of the nose.

[0048] (5) Ear loops: Ear loops made of spandex and nylon. They are connected to both sides of the mask body, used to fix the mask on the wearer's head, convenient for wearing and taking off, and have a certain elasticity to adapt to different head shapes and wearing habits.

[0049] The modified carbon fiber mask of the present invention is applicable to scenarios where the ozone concentration is below 1 ppm, and the decomposition rate of ozone is 80 - 90% at the inlet air flow rate of 0.2 - 0.5 m / s during normal human breathing. It is applicable to areas that need protection such as hospitals and industrial parks.

[0050] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art. The reagents or raw materials used, unless otherwise specified, are all purchased from commercial channels or have been made public.

[0051] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0052] The ultrasonic power during ultrasonic impregnation in the embodiments is all 240W.

[0053] Example 1

[0054] A modified carbon fiber ozone-degrading mask is composed of a filter layer, a functional layer, a skin-friendly layer, a nose clip, and ear loops; among them, both the filter layer and the skin-friendly layer are non-woven fabric layers; the functional layer is located between the filter layer and the skin-friendly layer; the preparation method of the functional layer is as follows:

[0055] Step 1. Select carbon fiber tows with a diameter of 5 - 10 microns and press them into a mesh with a thickness of 1 - 2 mm. The weight of the carbon fiber tow mesh is 4 g. Then, wash away the surface impurities with deionized water and dry it.

[0056] Step 2. Immerse the carbon fiber mesh prepared in Step 1 in a mixed solution of sulfuric acid and hydrogen peroxide with a volume ratio of 1:1 at 60 °C for 10 min to obtain Carbon Fiber Precursor 1.

[0057] Step 3. Place Carbon Fiber Precursor 1 in a 0.5 mol / L Fe(NO3)3 solution at 50 °C and ultrasonically immerse it for 20 min. Then, dry it in a muffle furnace at 200 °C for 2 h and calcine it at 400 °C for 2 h to obtain Precursor 2.

[0058] Step 4. Place Precursor 2 in a 0.05 mol / L AgNO3 solution at 50 °C and ultrasonically immerse it for 20 min. Then, dry it in a muffle furnace at 200 °C for 2 h and calcine it at 400 °C for 2 h to obtain the modified carbon fiber mesh.

[0059] Effect Verification

[0060] 1. Place the mask of Example 1 in a transparent glass box of appropriate size with both ends open, ensuring that the area of the mask can cover the cross-sectional area of the constant temperature box.

[0061] 2. Place the ozone generator and ozone concentration monitor in front of and behind the mask and set the concentration of the ozone generator.

[0062] 3. After stabilization, obtain the readings of the ozone concentration monitor.

[0063] 4. Results

[0064]

[0065]

[0066] Comparative Example 1

[0067] The difference from Example 1 is only that Step 4 is omitted, and the other steps and parameters are the same as those in Example 1.

[0068] A humid environment provides a good growth environment for bacteria. Silver oxide will slowly release silver ions (Ag+) in water or a humid environment, and silver ions are the main antibacterial active components. These silver ions play an antibacterial role by destroying the microbial cell membrane, interfering with metabolism, and genetic material replication.

[0069] Using the same ozone degradation test method as in Example 1, the test results are as follows:

[0070] <![CDATA[Set concentration (μg / m 3 )]]> Speed (m / s) <![CDATA[Concentration after degradation (μg / m 3 )]]> 160 0.5 46 200 0.5 62 500 0.5 148 800 0.5 264 1100 0.5 337 1400 0.5 488

[0071] Comparative Example 2

[0072] It is only different from Example 1 in that step 3 is omitted, and the remaining steps and parameters are the same as those in Example 1.

[0073] As a catalyst for the reaction of ozone with carbon, the omission of the addition of iron will lead to a slow reaction and low efficiency of ozone degradation.

[0074] Using the same ozone degradation test method as in Example 1, the test results are as follows:

[0075] <![CDATA[Set concentration (μg / m 3 )]]> Speed (m / s) <![CDATA[Concentration after degradation (μg / m 3 )]]> 160 0.5 66 200 0.5 86 500 0.5 213 800 0.5 344 1100 0.5 460 1400 0.5 627

[0076] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of ozone-degraded modified carbon fiber, characterized in that, It includes the following steps: The carbon fiber is impregnated in a mixed solution of sulfuric acid and hydrogen peroxide for pretreatment to obtain carbon fiber precursor 1; The carbon fiber precursor 1 is impregnated in an iron salt solution, then dried and calcined to obtain precursor 2; The precursor 2 is impregnated in a silver salt solution, then dried and calcined to obtain modified carbon fiber.

2. The preparation method of the ozone-degraded modified carbon fiber according to claim 1, characterized in that, The diameter of the carbon fiber is 5-10 microns.

3. The preparation method of the ozone-degraded modified carbon fiber according to claim 1, characterized in that, The volume ratio of the sulfuric acid to the hydrogen peroxide is 1:1; the temperature of the pretreatment is 50-60 °C and the time is 5-15 min.

4. The preparation method of the ozone-degraded modified carbon fiber according to claim 1, characterized in that, The iron salt solution is Fe(NO3)3 solution; the concentration of the Fe(NO3)3 solution is 0.2-0.5 mol / L; the silver salt solution is AgNO3 solution; the concentration of the AgNO3 solution is 0.02-0.05 mol / L.

5. The preparation method of the ozone-degraded modified carbon fiber according to claim 1, characterized in that, The temperature of the impregnation is 40-60 °C and the time is 15-20 min; the impregnation method is ultrasonic impregnation; the power of the ultrasonic wave is 240 W.

6. The preparation method of the ozone-degraded modified carbon fiber according to claim 1, wherein, The parameters of the drying are set as: keeping warm at 200 °C for 2 h; the parameters of the calcination are set as: keeping warm at 400 °C for 2 h.

7. A modified carbon fiber prepared by the preparation method according to any one of claims 1-6.

8. An application of the modified carbon fiber according to claim 7 in degrading ozone in the air.

9. A carbon fiber mask modified by ozone degradation, characterized in that, It includes a functional layer, and the preparation method of the functional layer is: first, carbon fibers with a diameter of 5-10 microns are pressed into a mesh with a thickness of 1-2 mm, and then the mesh is modified by the preparation method according to any one of claims 1-6 to obtain a modified carbon fiber mesh.

10. The ozone-degrading modified carbon fiber mask according to claim 9, wherein, The modified carbon fiber mask further includes a filter layer, a skin-friendly layer, a nose clip and ear straps; both the filter layer and the skin-friendly layer are non-woven fabric layers; the functional layer is located between the filter layer and the skin-friendly layer.

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