WO2022053075A1 - Thermally comfortable pm2.5-proof nanofiber mask filter element and manufacturing method therefor - Google Patents

Abstract

The invention discloses a thermally comfortable PM2.5-proof nanofiber mask filter element and a manufacturing method therefor, comprising an infrared light transmitting inner layer filter element (5) on the side near to the skin, and a visible light blocking outer layer filter element (6) on the side near to the environment. The two layers of filter elements are densely stitched. The manufacturing method comprises the following steps: (1) preparing a spinning solution A; (2) electrostatic spinning; (3) drying the nanofiber filter element film material prepared in step (2) in a constant temperature environment of 25-35°C to obtain a high-efficiency filtration mask filter element inner layer a; (4) preparing a spinning solution B; (5) adding spinning solution B to the electrostatic spinning apparatus of step (2), and by means of electrostatic spinning, obtaining a polymer nanofiber film b; (6) preparing a nanofiber film c; (7) preparing a nanofiber film d; (8) drying the nanofiber film d prepared in step (7) in a vacuum environment at 60-90°C to obtain a mask filter element outer layer e coated in thermally insulating particles and having a visible light blocking function; and (9) densely stitch the filter element inner layer a and the filter element outer layer e to obtain a thermally comfortable PM2.5-proof mask filter element.

Description

Thermal comfort anti-PM2.5 nanofiber mask filter element and preparation method thereof technical field

The invention belongs to the technical field of air filter materials, and in particular relates to a thermal comfort and PM _2.5 -proof nanofiber mask filter element and a preparation method thereof.

Background technique

The particulate matter suspended in the air and the bacteria attached to the particulate matter seriously affect people's daily life and health. Affected by the new coronary pneumonia, masks have become an indispensable protective item in people's daily life. While people are pursuing effective filtering of particulate pollutants, new requirements are also put forward for the comfort of masks.

Face sultry feeling caused by wearing a mask is common. At present, commercial ordinary disposable masks are light and thin but cannot effectively protect PM _2.5 . Disposable medical masks and N95 masks have good protective performance but do not consider the thermal comfort of the human face.

Electrospinning technology is a simple and effective method to prepare nanoporous polymer fiber materials. It has the advantages of controllable pore size, easy functionalization, and convenient operation. It is widely used in filter materials.

In May 2017, patent CN107048538A disclosed a three-layer composite antibacterial and anti-haze mask and its preparation method. The patent obtained nanofiber material by electrospinning method, and then processed by pre-oxidation, carbonization, and direct electrospinning again. Obtain antibacterial fiber membrane, and can filter and kill harmful bacteria. The filtration efficiency is ≥99%, the air permeability is ≥18 cm/s, and the filtration resistance is less than 120 Pa. The filter material can achieve high-efficiency filtration and kill germs, but does not consider the stuffy and wet feeling on the human face, which affects the comfort of the human body when wearing it.

In December 2013, the patent CN104740934A disclosed a three-dimensional electrospinning filter material for masks and a preparation method thereof. The patent uses electrospinning technology to change the receiving device into a metal mesh that fits the three-dimensional model of the human face. The fiber diameter of the electrospun micro-nanofiber membrane is between 0.2 and 1 μm, and the three-dimensional shape has a high degree of closeness to the human face. The filtration efficiency of PM _2.5 and PM _1.0 reaches 100%, and the air permeability is less than or equal to 200 Pa. This patent satisfies the wearer's facial comfort in terms of physical structure, but does not consider the sultry feeling of the human face.

In October 2019, the patent CN110660875A disclosed a method for cooling photovoltaic modules using transparent mid-infrared radiation cellulose films. This patent embeds transparent materials with infrared radiation capability into photovoltaic modules so that they can pass through the atmosphere in working conditions. The thermal radiation in the window band can be used to cool photovoltaic modules, but this zero-energy surface cooling technology has not been applied to human face filters.

technical solutions

The purpose of the present invention is to: provide a kind of thermal comfort anti-PM _2.5 nanofiber mask filter element suitable for human face and preparation method thereof, mainly using the principle of radiation cooling, processing functionalities by methods such as electrospinning and chemical technology A polymer material, a mask filter element material with good PM _2.5 filterability and facial thermal comfort is prepared.

The filter element material is composed of a polymer nanofiber film that can pass through the mid-infrared band of the human body and a nanofiber film that can block the visible light band of the atmospheric environment. Among them, nano-particles with anti-reflection infrared function are added to the infrared-transmitting nanofiber membrane to achieve the purpose of assisting the dissipation of thermal radiation generated by the human body, and serve as the inner layer of the thermal comfort mask filter element. Among them, the nanofiber membrane that blocks visible light is added with radiation heat-insulating particles to reduce the thermal radiation of the atmospheric environment to the human body, which is used as the outer layer of the thermal comfort mask filter element.

The object of the present invention is achieved through the following technical solutions.

A thermal comfort anti-PM _2.5 nanofiber mask filter element includes an infrared-transmitting inner layer filter element close to the skin side and a visible light-blocking outer layer filter element close to the environment side, and the two-layer filter element is densely sewn.

Preferably, the inner filter element is a nanofiber film added with nanoparticles having anti-reflection infrared function, and the outer filter element is a nanofiber film added with visible radiation blocking particles.

Preferably, the infrared-transmitting polymer of the inner and outer layers of the filter element is one or more of polyacrylonitrile, polyethylene, polyamide and polyethylene terephthalate.

Preferably, the particles with anti-reflection infrared function may be one or more of calcium fluoride, magnesium fluoride, zinc oxide, and the like.

Preferably, the heat insulating nanoparticles can be one or more of silicon dioxide, titanium dioxide and chromium dioxide, and the particle size is 10-80 nm.

Preferably, the thermal comfort filter element has the function of penetrating the infrared radiation of the human body and blocking the visible light of the atmospheric environment; the transmittance to the infrared band of the human body is ≥ 85%, and the transmittance to the visible light band is ≤ 60%.

Preferably, the inner filter element can pass through the thermal radiation emitted by the human face, and the infrared transmittance to the human body is ≥ 85%, so as to achieve the purpose of dissipating the radiant heat of the human body.

Preferably, the outer filter element can block the thermal radiation of the surrounding environment to the human body, and the transmittance of the outer filter element to the visible light thermal radiation in the atmosphere is less than or equal to 60%.

Preferably, the filter element of the mask has a gram weight of 3.3 to 5 g/m ² , a moisture permeability of 0.01 to 0.02 g/(cm ² h), a porosity of ≥85%, and an average fiber diameter of 0.2 to 1 μm. The filtration efficiency of 0.3 μm particles is 90% ~ 99.95%, and the resistance is 3 ~ 200 Pa, which can achieve high-efficiency filtration of PM _2.5 .

Any of the above-mentioned preparation methods for the air filter mask filter element material of the thermal comfort performance of the human face, comprising the following steps:

(1) Preparation of spinning solution A: Mix the polymer and the solvent evenly, then add the particles with anti-reflection infrared function, ultrasonically vibrate until the particles are evenly dispersed, and stir at room temperature to obtain a stable polymer spinning solution A;

(2) Electrospinning: First, change the roller metal plate of the electrospinning device to a copper mesh plate with better conductivity, adjust the process parameters, set the environmental parameters, and add the spinning solution A to the electrospinning device. , the nanofiber membrane material was prepared by electrospinning;

(3) drying the nanofiber membrane material prepared in step (2) in a constant temperature environment of 25-35 °C to obtain the inner layer a of the high-efficiency filter mask filter element with infrared permeation performance;

(4) Preparation of spinning solution B: Mix the polymer and solvent, and stir at room temperature for 8-10 h to obtain spinning solution B. Note that the polymer and solvent of spinning solution B are the same as those of spinning solution A;

(5) adding the spinning solution B to the electrospinning device, and obtaining the polymer nanofiber membrane b through electrospinning;

(6) Preparation of solution C: Add inorganic particles M into an aqueous solution of hydrochloric acid to obtain solution C, soak the nanofiber membrane b in solution C and activate it for 2 to 20 min, remove the membrane and wash it with deionized water for 1 to 3 times to obtain nanofiber membrane c;

(7) Preparation of precursor solution D: add solute N into water to obtain solution D, soak the nanofiber membrane c in solution D and put it into the diluted acidic aqueous solution E, then put it into an ultrasonic instrument, and sonicate it for 4 to 6 hours. Wash 1 to 3 times with deionized water and absolute ethanol, respectively, to obtain nanofiber membrane d;

(8) drying the fiber membrane d prepared in (7) in a vacuum environment of 60-90 °C to obtain the outer layer e of the mask filter element with the function of blocking visible light covered by heat insulating particles;

(9) The inner layer a of the filter element and the outer layer e of the filter element are intensively stitched to obtain a thermally comfortable anti-PM _2.5 mask filter element.

Preferably, the polymer in step (1) is one or more of polyacrylonitrile, polyethylene, polyamide and polyethylene terephthalate; the solvent in step (1) is formic acid, N , one or more of N-dimethylformamide; the particles with anti-reflection infrared function described in step (1) are one or more of calcium fluoride, magnesium fluoride and zinc oxide.

Preferably, the mass concentration of the polymer described in step (1) in the spinning solution is 12 ~ 20 wt.%; the concentration of particles with anti-reflection infrared function in the polymer solution is 0.02 ~ 0.16 mol/L;

Preferably, the drying time described in step (3) is 18 to 24 hours;

Preferably, in step (6), the inorganic particles M are one or more of tin dichloride and palladium chloride; in step (7), the solute N is ammonium fluorotitanate, one of zirconium oxychloride or Several; the acidic aqueous solution can be one or more of boric acid, hydrochloric acid and formic acid.

Preferably, in step (2) and step (5), the electrospinning device includes a bolus injection system, a spinning solution injection system, an electrostatic high voltage system and an improved copper rotating roller receiving system; the electrospinning system The process parameters are set as the electrospinning voltage is 15 ~ 25 KV, the receiving distance is 10 ~ 20 cm, the injection speed is 0.05 ~ 0.25 mm/min, temperature is 18 ~ 35℃, relative humidity is 30 ~ 70%;

Preferably, the mass concentration of the polymer described in step (4) in the spinning solution is 12 ~ 20 wt.%;

Preferably, the mass concentration of the inorganic particles M in the solution C described in step (6) is 0.3 to 0.5 wt.%;

Preferably, the concentration of the solute N in the precursor solution D described in step (7) is 0.01-0.05 mol/L, and the concentration of the acidic aqueous solution is 0.02-0.03 mol/L;

Preferably, the vacuum drying time in step (8) is 8-10 hours.

beneficial effect

Compared with the prior art, the present invention has the following advantages and beneficial effects:

The thermal comfort and anti-PM _2.5 nanofiber mask filter element of the present invention has an average fiber diameter of 0.2 to 1 μm, a porosity of the membrane ≥ 85%, a moisture permeability of 0.01 to 0.02 g/(cm ² h), and an average fiber diameter of ≥ 0.3 μm. The filtration efficiency of particles is 90% to 99.95%, and the resistance is 3 to 200 Pa. The infrared transmittance of the prepared thermal comfort mask filter element to the human body is ≥85%, and the visible light transmittance that carries a large amount of radiant heat in the environment is ≤60%. %.

The invention introduces the concept of radiative cooling, combines zero energy consumption surface cooling technology with nanofiber filter material, and realizes thermal comfort of human face and efficient filtration of PM _2.5 by enhancing the transmittance of infrared light and weakening the transmittance of visible light. sex.

The present invention ensures that the fiber filter element material has the anti-PM _2.5 function while satisfying the thermal comfort of the human body to the face by controlling the porosity of the nanofiber material and the diameter of the material by controlling the porosity of the nanofiber material and the radiation cooling property of the material through the chemical process method mainly based on the electrospinning process. demand.

The manufacturing method of the thermal comfort mask filter element material of the present invention is relatively simple. Preparation of thermal comfort mask filter element membrane material.

Description of drawings

FIG. 1 is a schematic structural diagram of an electrospinning device used in the present invention.

The numbers in the figure are explained as follows: 1- Bolus injection system of the electrospinning device; 2- Spinning solution injector; 3- Electrostatic high voltage system; 4- Rotating roller shaft receiving system.

2 is a schematic structural diagram of the thermal comfort mask filter element material of the present invention.

The numbers in the figure are explained as follows: 5-transmitting the inner layer of the filter element of the infrared mask; 6-blocking the outer layer of the filter element of the visible mask.

3 is the Fourier infrared transform spectrogram of the filter element material of Example 1 and the disposable mask of Comparative Test Example 1.

Fig. 4 is the Fourier infrared transform spectrogram of embodiment 2 filter element material and the disposable mask of comparative test example 1.

Fig. 5 is the Fourier infrared transform spectrogram of embodiment 3 filter element material and the disposable mask of comparative test example 1.

Fig. 6 is the UV-Vis spectrophotometer test chart of the filter element material of the embodiment.

7 is a comparison diagram of the capture efficiency of the disposable masks and KN95 masks of Examples 1-3 and Comparative Test Example 2 to particles of different diameters.

Fig. 8 is the filtration pressure drop comparison diagram of the disposable mask of embodiment 1-3 and comparative test example 3 and KN95 mask.

Embodiments of the present invention

The specific implementation of the present invention will be further described below with reference to specific embodiments and accompanying drawings, but the implementation and protection scope of the present invention are not limited thereto.

Example 1

A preparation method of a thermal comfort anti-PM _2.5 nanofiber mask filter element, the specific steps are:

(1) Add 2 g of polyamide 66 to 8 g of formic acid and mix, stir evenly with a glass rod, pay attention to open the fume hood when taking formic acid; add 0.75 g of zinc oxide (purity 99.5%, average particle size 20 nm) Placed in the above mixed solvent, shaken with an ultrasonic oscillator for 1.5 h, and stirred evenly to prepare solution A;

(2) The injection system for adding the spinning solution A to the electrospinning device (see FIG. 1 ), which includes a bolus injection system 1 , an injection system 2 , an electrostatic high voltage system 3 and a receiving system 4 . The receiving system was improved to a copper mesh receiving plate, and the electrospinning process parameters were as follows: the receiving distance was 15 cm, the electrostatic high voltage was 20 KV, the injection speed was 0.1 mm/min, the temperature was 35 °C, and the relative humidity was 60%. The nanofiber membrane was obtained after 30 min of spinning time;

(3) After drying the membrane in a constant temperature environment of 30 °C for 24 h, the inner layer a of the filter element of the infrared transparent mask was obtained;

(4) Mix 2 g of polyamide 66 with 8 g of formic acid, stir and mix with a glass rod, and magnetically stir for 9 hours to obtain spinning solution B;

(5) Electrospinning (4) spinning solution B, wherein the equipment and parameters are the same as in step (2), to obtain nanofiber membrane b;

(6) Add 4 g of tin dichloride to 1 L of hydrochloric acid (37% by mass) to prepare solution C; soak the fiber membrane b obtained in (5) in C for 5 min, take it out and wash with deionized water 3 times to obtain the wetted nanofiber membrane c;

(7) Add 2 g of ammonium fluorotitanate to 1 L of water to prepare solution D; add water to the boric acid solution to prepare solution E with a concentration of 0.03 mol/L, and soak the fiber membrane c obtained in (6) successively in the solution In D and solution E, sonicated for 5 h and washed twice with deionized water and absolute ethanol, respectively, to obtain nanofiber membrane d coated by titanium dioxide;

(8) Place the fiber membrane d obtained in (7) in a vacuum environment of 60 to 90 °C for 8 h to dry to obtain the outer layer e of the filter element of the visible mask;

(9) Intensive suturing of the inner layer a of the filter element and the outer layer e of the filter element to obtain the described mask filter element membrane material with thermal comfort and anti-PM _2.5 function.

The infrared transmittance of the filter element of the mask made in this example is 85 to 90% in the human body (see Figure 3), and the transmittance of the filter element material to visible light is ≤ 50% (see Figure 6); the SEM image is analyzed using image-Proplus software. The average fiber diameter of the obtained mask filter element is 200 nm, using the filter material test platform built in the laboratory to obtain the filter material when the wind speed is 5.3 cm/s, the filtration efficiency of 0.3 μm particles is 96.49% (see Figure 7), and the pressure drop is 102 Pa (see Figure 8) .

Example 2

A preparation method of a thermal comfort anti-PM _2.5 nanofiber mask filter element, the specific steps are:

(1) Mix 1.2 g of polyamide 6 and 8.6 g of formic acid evenly, pay attention to wear a gas mask and open the fume hood when handling formic acid; put 0.12 g of calcium fluoride in the above mixed solvent, shake it with an ultrasonic oscillator for 1.5 h, stir to prepare solution A;

(2) The injection system for adding the spinning solution A to the electrospinning device (see FIG. 1 ), which includes a bolus injection system 1 , an injection system 2 , an electrostatic high voltage system 3 and a receiving system 4 . The receiving system was improved to a copper mesh receiving plate, and the electrospinning process parameters were: receiving distance of 10 cm, electrostatic high voltage of 25 KV, injection speed of 0.05 mm/min, temperature of 28 °C, relative humidity of 35%, The spinning time was 30 min to obtain a nanofiber membrane;

(3) Dry the membrane in a constant temperature environment of 25 °C for 22 h to obtain the inner layer a of the infrared transparent filter element;

(4) Mix 1.2 g of polyamide 6 and 8.6 g of formic acid uniformly, and stir at room temperature for 10 h to obtain spinning solution B;

(5) Electrospinning (4) spinning solution B, wherein the equipment and parameters are the same as in step (2), to obtain nanofiber membrane b;

(6) Add 5 g of tin dichloride to 1 L of hydrochloric acid (37% by mass) to prepare solution C; soak the fiber membrane b obtained in (5) in C for 3 min, take it out and wash with deionized water 3 times to obtain nanofiber membrane c;

(7) Add 2 g of ammonium fluorotitanate to 1 L of water to prepare solution D; add water to the boric acid solution to prepare solution E with a concentration of 0.03 mol/L, and soak the fiber membrane c obtained in (6) successively in the solution D and solution E were washed twice with deionized water and absolute ethanol after sonication for 6 h, respectively, to obtain nanofiber membrane d coated by titanium dioxide;

(8) Place the fiber membrane d obtained in (7) in a vacuum environment of 60 to 90 °C for 9 hours to dry to obtain the outer layer e of the filter element of the mask with visible resistance;

(9) Intensive suturing of the inner layer a of the filter element and the outer layer e of the filter element to obtain the described mask filter element membrane material with thermal comfort and anti-PM _2.5 function.

The infrared transmittance in the human body of the mask filter element prepared in this example is 87.13 to 97.63% (see Figure 4), and the transmittance of the filter element material to visible light is ≤ 60% (see Figure 6); the SEM image is analyzed by image-Proplus software. The average fiber diameter of the obtained mask filter element obtained by analysis was 365 nm, and the moisture permeability was 0.0131 g/cm ² /h. The filter material test platform built by the laboratory was used to obtain the filter material at a wind speed of 5.3. At cm/s, the filtration efficiency for 0.3 μm particles is 97.12% (see Figure 7), and the pressure drop is 80 Pa (see Figure 8).

Example 3

A preparation method of a thermal comfort anti-PM _2.5 nanofiber mask filter element, the specific steps are:

(1) Mix 1.87 g of polyacrylonitrile and 13.68 g of N,N-dimethylformamide uniformly; put 0.15 g of magnesium fluoride in the above mixed solvent, shake it with an ultrasonic oscillator for 1.5 h, and stir to prepare a solution. A;

(2) The injection system for adding the spinning solution A to the electrospinning device (see FIG. 1 ), which includes a bolus injection system 1 , an injection system 2 , an electrostatic high voltage system 3 and a receiving system 4 . The receiving system was improved to a copper mesh receiving plate, and the electrospinning process parameters were as follows: the receiving distance was 20 cm, the electrostatic high voltage was 20 KV, the injection speed was 0.1 mm/min, the temperature was 26 °C, and the relative humidity was 50%. Spinning time is 40min, obtains nanofiber membrane;

(3) Dry the membrane in a constant temperature environment of 35 °C for 18 h to obtain the inner layer a of the infrared transparent filter element;

(4) Mix 1.87 g of polyacrylonitrile and 13.68 g of N,N-dimethylformamide uniformly, and stir at room temperature for 8 h to obtain spinning solution B.

(5) Electrospinning (4) spinning solution B, wherein the equipment and parameters are the same as in step (2), to obtain nanofiber membrane b;

(6) Add 4 g of tin dichloride to 1 L of hydrochloric acid (37% by mass) to prepare solution C; soak the fiber membrane b obtained in (5) in C for 8 min, take it out and wash with deionized water 3 times to obtain nanofiber membrane c;

(7) Add 3 g of ammonium fluorotitanate to 1 L of water to prepare solution D; add water to the boric acid solution to prepare solution E with a concentration of 0.03 mol/L, and soak the fiber membrane c obtained in (6) in solution D successively and solution E, washed with deionized water and absolute ethanol for 3 times respectively after sonicating for 5 h to obtain the nanofiber membrane d coated by titanium dioxide;

(8) Place the fiber membrane d obtained in (7) in a vacuum environment of 60 to 90 °C for 10 hours to dry to obtain the outer layer e of the filter element of the mask with visible resistance;

(9) Intensive suturing of the inner layer a of the filter element and the outer layer e of the filter element to obtain the described mask filter element membrane material with thermal comfort and anti-PM _2.5 function.

The infrared transmittance of the mask filter element made in this example is 81.94-98.1% in the human body (see Figure 5), and the transmittance of the filter element material to visible light is less than or equal to 60% (see Figure 6); use image-Proplus software to analyze the SEM image The average fiber diameter of the obtained mask filter element was 662 nm, and the filter material test platform built in the laboratory was used to obtain the filter element material at a wind speed of 5.3 nm. At cm/s, the filtration efficiency for 0.3 μm particles is 92.97% (see Figure 7) and the pressure drop is 27 Pa (see Figure 8).

Comparative test case 1

The Fourier infrared transform spectrum test of the disposable mask, the test is the same as that of Example 1-3; its mid-infrared transmittance≤5%, and the test result is shown in Figure 3-5.

Comparative test case 2

The capture efficiency test of disposable masks and KN95 masks for particles of different diameters, the test conditions are the same as in Example 1-3; next to the examples. The test results are shown in Figure 7.

Comparative test case 3

The filter pressure drop test of disposable masks and KN95 masks, the test conditions are the same as those of Example 1-3;

The test results are shown in Figure 8.

The above descriptions are merely preferred embodiments of the present invention, and do not limit the present invention in any form. Any equivalent changes, modifications or evolutions made by those skilled in the art to the above embodiments by utilizing the technical solutions of the present invention still fall within the scope of the technical solutions of the present invention.

Claims (10)

A thermal comfort anti-PM _2.5 nanofiber mask filter, characterized in that it includes an infrared-transmitting inner filter close to the skin side and an outer visible light blocking filter close to the environment, and the two-layer filter is intensively stitched. A kind of thermal comfort anti-PM _2.5 nanofiber mask filter core according to claim 1, is characterized in that, described inner layer filter core is the nanofiber film that adds the nanoparticle with anti-reflection infrared function, described outer layer The filter element is a nanofiber membrane with added visible radiation blocking particles. A kind of thermal comfort anti-PM _2.5 nanofiber mask filter core according to claim 1, is characterized in that, described inner layer filter core can pass through the thermal radiation that human face emits, to human body infrared transmittance ≥ 85%; The outer layer filter element can block the thermal radiation of the surrounding environment to the human body, and the transmittance of the outer layer filter element to the visible light thermal radiation in the atmosphere is less than or equal to 60%. A kind of thermal comfort anti-PM _2.5 nanofiber mask filter core according to claim 1, is characterized in that, the average fiber diameter of described nanofiber mask filter core is 0.2～1 μm, the porosity of described nanofiber mask filter core ≥ 85%, the filtration efficiency for ≥ 0.3 µm particles is 90% ~ 99.95%, and the resistance is 3 ~ 200 Pa, which can achieve high-efficiency filtration of PM _2.5 . A preparation method of a thermal comfort anti-PM _2.5 nanofiber mask filter element, characterized in that, comprising the steps: (1) Preparation of spinning solution A: Mix the polymer and the solvent evenly, then add the particles with anti-reflection infrared function, ultrasonically vibrate until the particles are evenly dispersed, and stir at room temperature to obtain a stable polymer spinning solution A; (2) Electrospinning: First, change the roller metal plate of the electrospinning device to a copper mesh plate with better electrical conductivity, adjust the process parameters, set the environmental parameters, and add the spinning solution A to the electrospinning. In the device, the nanofiber filter element membrane material is prepared by electrospinning; (3) drying the nanofiber filter element membrane material prepared in step (2) at a constant temperature of 25-35 °C to obtain the inner layer a of the high-efficiency filter mask filter element with infrared permeation performance; (4) Preparation of spinning solution B: Mix the polymer and solvent, and stir at room temperature for 8-10 h to obtain spinning solution B. The polymer and solvent of spinning solution B are the same as the spinning solution in step (1). The polymer and solvent of A are the same; (5) adding the spinning solution B to the electrospinning device of step (2), and obtaining a polymer nanofiber membrane b through electrospinning; (6) Preparation of solution C: adding inorganic particles M into an aqueous solution of hydrochloric acid to obtain solution C, soaking the nanofiber membrane b in the solution C and then activating it for 2-20 min, take out the nanofiber membrane b and wash it with deionized water for 1 to 3 times to obtain the nanofiber membrane c; (7) Preparation of precursor solution D: add solute N into water to obtain solution D, soak the nanofiber membrane c in the solution D, and then put it into the diluted acidic aqueous solution E, take out the fiber membrane and put it into the solution D. In the ultrasonic instrument, after ultrasonication for 4 to 6 hours, the nanofiber membrane d is obtained by washing with deionized water and absolute ethanol for 1 to 3 times respectively; (8) drying the nanofiber membrane d prepared in (7) in a vacuum environment of 60～90° C. to obtain the outer layer e of the mask filter element with the function of blocking visible light covered by heat insulating particles; (9) The thermal comfort anti-PM _2.5 mask filter element obtained by intensive stitching of the inner layer a of the filter element and the outer layer e of the filter element. The preparation method according to claim 5, wherein the polymer in step (1) is one or more of polyacrylonitrile, polyethylene, polyamide and polyethylene terephthalate; step (1) The solvent is one or more of formic acid and N,N-dimethylformamide; the particles with antireflection infrared function described in step (1) are calcium fluoride, magnesium fluoride, oxide One or more of zinc. The preparation method according to claim 5, wherein the concentration of particles with anti-reflection infrared function in the spinning solution A obtained in step (1) is 0.02 to 0.16 mol/L; the polymer in step (1) The mass concentration in spinning solution A is 12 ~ 20 wt.%; the drying time described in step (3) is 18 to 24 hours. The preparation method according to claim 5, wherein the inorganic particles M in step (6) are one or more of tin dichloride and palladium chloride; the solute N in step (7) It is one or more of ammonium fluorotitanate and zirconium oxychloride, and the acidic aqueous solution is one or more of boric acid, hydrochloric acid and formic acid. The preparation method according to claim 5, wherein the mass concentration of the polymer described in step (4) in the spinning solution is 12-20 wt.%; the mass concentration of the inorganic particles M in step (6) is 0.3-0.5 wt.%; in the step (7), the concentration of the solute N in the precursor solution D is 0.01-0.05 mol/L, and the concentration of the acidic aqueous solution E is 0.02-0.03 mol/L; the step (8) described Drying time is 8 to 10 hours. The method for preparing a thermal comfort anti-PM _2.5 nanofiber mask filter element according to any one of claims 5 to 9, wherein the electrospinning device in step (2) and step (5) comprises a bolus injection system, a spinning solution injection system, an electrostatic high-voltage system and an improved copper rotating roller receiving system; the electrospinning process parameters described in steps (2) and (5) are: the spinning voltage is 15-25 KV, the receiving system is The distance is 10 ~ 20 cm, the injection speed is 0.05 ~ 0.25 mm/min, the temperature is 18 ~ 35 ℃, and the relative humidity is 30 ~ 70%.