CN114803160A

CN114803160A - Moisture absorption bag and preparation method thereof

Info

Publication number: CN114803160A
Application number: CN202110107445.XA
Authority: CN
Inventors: 王丹阳; 高婷婷; 郭国良; 郑军妹
Original assignee: Ningbo Fotile Kitchen Ware Co Ltd
Current assignee: Ningbo Fotile Kitchen Ware Co Ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2022-07-29
Anticipated expiration: 2041-01-27
Also published as: CN114803160B

Abstract

The invention relates to a moisture absorption bag and a preparation method thereof, wherein the moisture absorption bag comprises a bag body and a drying agent arranged in the bag body, and the moisture absorption bag is characterized in that the bag body comprises a hydrophobic layer and a hydrophilic layer, wherein the hydrophobic layer and the hydrophilic layer are sequentially overlapped from inside to outside, the hydrophobic layer can allow water vapor to pass through but cannot allow liquid water to pass through, and the hydrophilic layer and the hydrophobic layer are both nanofiber layers prepared through electrostatic spinning. The bag body is of a nanofiber structure prepared by an electrostatic spinning method, and is good in waterproof and moisture-permeable performance.

Description

Moisture absorption bag and preparation method thereof

Technical Field

The invention relates to a dehumidifying bag and a preparation method thereof, wherein the dehumidifying bag can be arranged in places with much moisture, such as closets, multi-drawer cabinets, wardrobe cabinets, shoe cabinets, the peripheries of commodes, the lower parts of pools, clothes storage boxes and the like.

Background

In spring and summer, rainwater is more, particularly, the humidity is higher in southern areas, the human body comfort level is reduced due to over-wetting, and in summer, in three-volt seasons, due to the effects of high temperature, low pressure and high humidity, human sweat is not easy to discharge, and is not easy to evaporate after sweating, so that people can feel irritated, tired and inappetence, and the damp air causes the easy mildew of clothes, wooden furniture and the like, and the life of people is also greatly disturbed.

The household air humidity adjusting device is commonly used for air conditioners, dehumidifiers and other electrical appliances, but if the energy consumption for continuous work is too high, all areas of the household environment cannot be covered, and the humidity of the electrical appliances can be rapidly increased after the electrical appliances stop working, so that the requirement for long-term dehumidification cannot be met. The dehumidification box, the hanging dehumidification bag and other products have low cost, but have higher requirements on the use and placement form of the products, otherwise the dehumidification box is easy to overflow when toppling over.

Waterproof moisture permeable fabrics are becoming more and more attractive, waterproof meaning that the material has the ability to withstand liquid water or rain, snow, fog, and moisture permeability meaning that the fabric has the ability to allow water vapor to pass through the fabric when there is a difference in humidity between the two sides of the fabric. In order to impart waterproof and moisture-permeable properties to fabrics, two methods are generally used: firstly, according to the size difference between the diameters of water vapor molecules and water drops and the size of pores of the fabric, the pore size range of the fabric is between the diameters of the water vapor molecules and the water drops, so that the waterproof and moisture permeable effects are achieved; secondly, according to the chemical adsorption effect, the hydrophilic chain segment of the membrane can absorb water vapor to obtain moisture permeability, and the hydrophobic chain segment obtains waterproofness. At present, Gore-Tex is taken as a representative of waterproof moisture-permeable fabrics, and the waterproof moisture-permeable fabrics have good waterproof moisture-permeable performance, but the application of the waterproof moisture-permeable fabrics is limited due to high price caused by complex process and high cost.

As shown in a "dehumidification bag" disclosed in chinese patent application No. CN201880055366.5 (publication No. CN111050881A), the dehumidification bag includes a bag body made of a moisture-permeable waterproof sheet and a moisture absorbent sealed inside the bag body, the bag body is formed in a three-dimensional shape having a plurality of planar portions, one of the planar portions is a bottom surface that is in contact with a placement surface of an installation site, and the other of the planar portions is a moisture absorption surface that is opposed to a space of the installation site, and the bag body is made of a moisture-permeable waterproof sheet or a moisture-permeable film having minute vent holes (not shown) in units of several micrometers, and is configured to pass moisture through the minute vent holes but not to pass liquid therethrough.

In order to prevent the deliquescent liquid liquefied by moisture absorption from leaking from the bag body and staining clothes and bedclothes, the moisture-removing bag needs to incorporate a thickener (gelling agent) into the deliquescent substance, which is costly; in addition, the dehumidifying bag does not disclose what structure the bag body has, and can achieve an effect of allowing moisture to pass through the minute vent holes without allowing liquid to pass through (i.e., absorbing moisture without reverse osmosis).

Disclosure of Invention

The first technical problem to be solved by the invention is to provide an absorbent bag which has good hygroscopicity and does not cause reverse osmosis, aiming at the current situation of the prior art.

The second technical problem to be solved by the present invention is to provide a method for preparing the moisture absorption packet in view of the current situation of the prior art.

The technical scheme adopted by the invention for solving the first technical problem is as follows: the utility model provides a moisture absorption package, includes the bag body and locates the internal drier of bag, its characterized in that, the bag body includes that the ability that from interior to exterior superposes in proper order can supply water vapor to pass through and can not supply the hydrophobic layer that liquid water passes through and can absorb the hydrophilic layer of water vapor, hydrophilic layer and hydrophobic layer are the nanofiber layer of passing through electrostatic spinning preparation.

Preferably, the drying agent is at least one of calcium chloride, magnesium chloride, lithium bromide, potassium acetate, sodium phosphate and sodium metaphosphate.

In order to further improve the moisture absorption and seepage prevention effects of the bag body, the bag body further comprises a water absorption layer which expands after absorbing water and has smaller pores, the water absorption layer is arranged on the inner side of the hydrophobic layer, and the water absorption layer is also a nanofiber layer prepared through electrostatic spinning. After the water absorbing layer is arranged, the hydrophilic layer absorbs water vapor in a high-humidity environment at the outer side, the hydrophobic layer is arranged in the middle, the water absorbing layer is in contact with a calcium chloride desiccant, and in the first stage of moisture absorption: since the water-absorbing layer has a low initial moisture absorption rate, water vapor adsorbed by the hydrophilic layer is first absorbed by the desiccant, and the desiccant turns into liquid droplets. The liquid water droplet diameter is usually 100-3000 μm, and the vapor molecules are about 0.0004 μm. The film layer of the whole moisture absorption bag is provided with micropores with the size smaller than the diameter of the liquid water drops and larger than the diameter of the water vapor molecules, so that water cannot permeate under the action of surface tension, and the water vapor in the air can smoothly permeate the micropores through diffusion and convection, thereby achieving the purposes of water resistance and moisture permeability. Because the liquid water aperture is greater than the hydrophobic layer aperture, the liquid water can not pass through the hydrophobic layer to prevent water seepage. And (3) moisture absorption second stage: the desiccant absorbs moisture and is converted into salt solution to reach a certain amount, the water absorbing layer gradually expands along with the increase of the water absorbing amount, and the pore diameter of the water absorbing layer gradually becomes smaller, so that the reverse osmosis of water molecules is better prevented, the water retaining amount is good, and the water is difficult to permeate under pressure, so that the pressure resistance of the dehumidifying bag is improved. In other words, the water-absorbing layer absorbs water at a relatively low speed, and the desiccant absorbs water first to convert the water into water, and the water-absorbing layer absorbs water secondarily.

The technical scheme adopted by the invention for solving the second technical problem is as follows: the preparation method of the moisture absorption bag is characterized by comprising the following steps: the method comprises the following steps:

firstly, preparing spinning solution A and spinning solution B

Preparing a spinning solution A, wherein the preparation of the spinning solution A comprises the following steps:

(1.1) adding the hydrophilic modified nano particles into an organic solvent, and performing ultrasonic dispersion;

(1.2) adding a hydrophilic polymer into the step (1.1), stirring and dissolving at 40-80 ℃, defoaming after complete dissolution, and preparing into 5-20 wt% of spinning solution A;

the hydrophilic modified nano particles are at least one of silicon dioxide or titanium dioxide;

the polymer is at least one of polyacrylonitrile, polyvinyl alcohol, polyurethane, polymethyl methacrylate, nylon and polycarbonate;

II, preparing a spinning solution B, wherein the spinning solution B comprises the following steps:

(2.1) dissolving a hydrophobic polymer in an organic solvent, stirring and dissolving at 40-80 ℃, defoaming after complete dissolution, and preparing a spinning solution B with the concentration of 5-20 wt%;

the polymer is at least one of polystyrene, polyethylene, polypropylene, polyvinylidene fluoride and polyether sulfone;

secondly, preparing the nanofiber membrane, comprising the following steps:

(1) filling the spinning solution A into an injector A, and carrying out electrostatic spinning on the spinning solution A by taking non-woven fabrics as a substrate to obtain a hydrophilic layer;

(2) and then replacing the injector A, filling the spinning solution B into the injector B, and carrying out electrostatic spinning on the spinning solution B by taking the hydrophilic layer as a substrate to obtain a hydrophobic layer positioned on the inner side of the hydrophilic layer.

In order to better spin the spinning solution A, B, the electrostatic spinning method in step (1) is: filling the spinning solution A into an injector A, adjusting the voltage of spinning parameters to be 5-20kv, enabling the distance between the needle end of the injector A and a collector to be 5-15cm, arranging non-woven fabrics on the collector, enabling the injection speed to be 5-200ul/min, the rotating speed of the collector to be 300-3000rpm, the spinning temperature to be 20-30 ℃, the humidity to be 40-70% and the spinning time to be 5-20min, and obtaining the hydrophilic layer;

the electrostatic spinning method in the step (2) comprises the following steps: adjusting the spinning parameter voltage to be 5-20kv, the distance between the needle end of the injector B and the collector to be 5-15cm, the injection speed to be 5-200ul/min, the rotation speed of the collector to be 300-3000rpm, the spinning temperature to be 20-30 ℃, the humidity to be 40-70%, and the spinning time to be 5-20min, thereby obtaining the double-layer nanofiber membrane.

In order to better dissolve the polymer, in the step (1.1) or (2.1), the organic solvent is at least one of N, N-dimethylformamide or N, N-dimethylacetamide or dimethyl sulfoxide or acetone.

In order to enable the moisture absorption bag to purify air, tourmaline nano powder is added into the organic solvent in the step (1.1). Under the fluctuation of external sunlight, temperature and other energy, the tourmaline powder contacts with water molecules in the air or on the surface of the skin to generate an instantaneous discharge ionization effect, and the water molecules are electrolyzed into H + and OH-. H + is combined with electrons released by the tourmaline to be neutralized into H atoms, and OH-is combined with other water molecules to continuously generate hydroxyl anions. The air anions are known as "air vitamins" and are considered as the first element for supporting habitable cities and habitable communities. The air floats positively charged bacteria, viruses and harmful gases (the diameter is less than 10 mu m) for a long time, and negative ions emitted by the negative ion fibers can be neutralized with the positive ions. Meanwhile, the negative ions can effectively absorb and eliminate irritant gases such as benzene, formaldehyde, ammonia and the like, and the negative ions are beneficial to the respiratory system of a human body, can greatly improve the oxygen carrying capacity of blood, make the human body refreshing and refreshing, and are substances beneficial to the health of the human body. The drying agent in the bag body absorbs water vapor and then turns into water to react with the tourmaline nano powder on the fiber film to release a large amount of negative ions.

Preferably, in the steps (1.1) and (1.2), the diameter of the nano particles is 10-40 nm, so that the nano particles can be better mixed with hydrophilic polymers and are convenient for electrostatic spinning; the mass ratio of the nano particles to the hydrophilic polymer is 1 (5-20), so that spinning is facilitated; the mass ratio of the tourmaline nano powder to the hydrophilic polymer is 1 (5-15), so that the effect of purifying air can be achieved.

Preferably, in the step (2.1), a surfactant is further added to the organic solvent, and the surfactant is at least one of sodium dodecyl benzene sulfonate, cetyltrimethylammonium bromide, sodium dodecyl sulfate and cetyltrimethylammonium bromide. The surface active agent adjusts the surface tension to enable the fiber membrane to have a uniform nodular structure, structure the surface roughness and increase the hydrophobic effect.

Preferably, the mass ratio of the surfactant to the polymer is 1 (100-400). The surfactant can play a role in increasing the hydrophobic effect, and the spinning of the spinning solution B can not be influenced.

Preferably, the bag further comprises a water absorbing layer which expands after absorbing water and has smaller pores, the water absorbing layer is arranged on the inner side of the hydrophobic layer, and the first step further comprises

III, preparing a spinning solution C, comprising the following steps:

(3.1) mixing acrylic acid and deionized water, adding NaOH, stirring and mixing uniformly, then adding acrylamide, mixing uniformly, adding an initiator, stirring at 50-60 ℃ until the reaction is finished, cooling to room temperature, adding glutaraldehyde, and stirring uniformly to obtain 20-30 wt% of spinning solution C.

The second step further comprises the following steps:

(3) and (3) replacing the injector B, replacing the injector C with another injector C, injecting the spinning solution C, and carrying out electrostatic spinning on the spinning solution C by taking the hydrophobic layer prepared in the step (2) as a substrate to obtain a water absorbing layer positioned on the inner side of the hydrophobic layer.

Preferably, the second step further comprises a step (4) of heating the prepared three-layer nanofiber membrane at 120-180 ℃ for 2-5 hours. Because the water-absorbing layer is internally provided with the cross-linking agent, the interior of the water-absorbing layer is subjected to heat cross-linking by heating, the lap joint strength between fibers in the water-absorbing layer is enhanced, and the contact part of the water-absorbing layer and the hydrophobic layer also enhances the bonding degree.

Preferably, the mass ratio of the acrylic acid to the acrylamide to the NaOH is (2-4): 1, so that the stream effect of the water absorbing layer is ensured, the initiator accounts for 0.5-1.0% of the total mass of the acrylic acid and the acrylamide, the chemical combination between the acrylic acid and the acrylamide is ensured, and the glutaraldehyde accounts for 1-5% of the total mass of the acrylic acid and the acrylamide, so that the crosslinking effect is ensured.

In order to ensure that the spinning solution C can be spun, in the step (3), the electrostatic spinning method comprises: adjusting the spinning parameter voltage to 5-20kv, the distance between the needle end of the injector C and the collector to 5-15cm, the injection speed to 5-200ul/min, the rotation speed of the collector to 300-.

Compared with the prior art, the invention has the advantages that: 1. the hydrophilic layer absorbs water vapor in a high-humidity environment on the outer side, the hydrophobic layer is in contact with the drying agent, the drying agent absorbs the water vapor absorbed by the hydrophilic layer, and the drying agent is changed into liquid drops. The diameter of the liquid water drop is usually 100-3000 mu m, the diameter of the gas-state water vapor molecule is about 0.0004 mu m, the bag body of the invention is a nano fiber structure, the pore is a micropore which is smaller than the diameter of the liquid water drop and larger than the diameter of the water vapor molecule, so that water can not permeate under the action of surface tension, water vapor in the air can smoothly permeate the micropore through diffusion and convection, the pore diameter of the liquid water is larger than the pore diameter of the hydrophobic layer, and the water seepage can be prevented because the pore diameter of the hydrophobic layer can not permeate through the hydrophobic layer, so that the aim of water and moisture permeability is achieved, and the liquid drop can be prevented from permeating without adding a tackifier in a drying agent;

2. the bag body is of a nanofiber structure prepared by an electrostatic spinning method, is good in waterproof and moisture-permeable performance, does not need to specially design the geometric structure of the bag body, and can absorb moisture on all surfaces of the bag body;

3. the dehumidifying bag is convenient, small and easy to carry, can be placed in places such as a household kitchen, a wardrobe, a toilet and the like, can be carried with a user and placed in a luggage case, a sports backpack and the like, and can quickly and effectively absorb moisture in the dehumidifying bag, so that the dehumidifying bag is always in a dry and sanitary environment.

Drawings

FIG. 1 is a schematic structural view of an absorbent packet according to an embodiment of the present invention;

FIG. 2 is a partial schematic view of the pouch of FIG. 1;

FIG. 3 is a schematic view of an electrospinning apparatus;

fig. 4 is a schematic view of the hydrophobic angle of the hydrophobic layer of example 1;

FIG. 5 is an electron micrograph of the hydrophilic layer of example 1;

fig. 6 is an electron micrograph of the water-repellent layer of example 1.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

The moisture absorption bag of the following embodiments has the same structure, as shown in fig. 1 and 2, the moisture absorption bag includes a bag body 1 and a desiccant 2 disposed in the bag body 1, the desiccant 2 is at least one of calcium chloride, magnesium chloride, lithium bromide, potassium acetate, sodium phosphate and sodium metaphosphate, and in this embodiment, the desiccant 2 is selected from calcium chloride. After the drying agent 2 is added into the bag body 1, the bag mouth is fastened through the sealing strip.

The bag body 1 comprises a water absorption layer 13, a hydrophobic layer 11 and a hydrophilic layer 12 which are sequentially overlapped from inside to outside, the water absorption layer 13 expands after absorbing water, the pores become small, the hydrophobic layer 11 can allow water vapor to pass through but cannot allow liquid water to pass through, the hydrophilic layer 12 can absorb the water vapor, and the hydrophilic layer 12, the hydrophobic layer 11 and the water absorption layer 13 are all nanofiber layers prepared through electrostatic spinning.

The tourmaline nanopowder, polyvinylidene fluoride, acrylic acid, and acrylamide were purchased from Xinda mineral products, Inc., Lingshu county, Aladdin reagent, Inc., polyvinylidene fluoride, Plastic Large Plastic raw materials, Inc., Dongguan, City, Japan, and Industrial, Japan, second, third, second, third, fourth, third, fourth, third, fourth.

Example 1

The preparation method of the moisture absorption bag comprises the following steps:

step one, preparing a spinning solution A, a spinning solution B and a spinning solution C;

and step two, carrying out electrostatic spinning on the spinning solution A, the spinning solution B and the spinning solution C to prepare the nanofiber membrane.

The first step specifically comprises the following steps:

(1.1) adding 2g of hydrophilic modified silicon dioxide nano particles (the diameter is 10nm) into 85g of organic solvent N, N-Dimethylformamide (DMF), and carrying out ultrasonic dispersion for 2 h;

(1.2) adding 15g of Polyacrylonitrile (PAN) into the step (1.1), wherein the dissolving temperature is 40 ℃, mechanically stirring for 12h to dissolve the polyacrylonitrile in the organic solvent, standing for 12h to defoam after the polyacrylonitrile is completely dissolved, and preparing a spinning solution A with the concentration of 15% (15/(15+85), the same below) and the viscosity of the spinning solution A being 1780mPa & s;

(2.1) dissolving 5g of hydrophobic polyvinylidene fluoride (PVDF) and 0.05g of Sodium Dodecyl Benzene Sulfonate (SDBS) in 95g of organic solvent N, N-Dimethylformamide (DMF), wherein the dissolving temperature is 40 ℃, mechanically stirring for 12h, standing for 12h for defoaming after complete dissolution, preparing a spinning solution B with the concentration of 5 wt% (5/(5+95), the mass of the SDBS is small and can be ignored, the same below) and the viscosity of the spinning solution B is 579mPa & s;

III, preparing a spinning solution C, comprising the following steps:

(3.1) mixing 6g of acrylic acid and deionized water, adding 3g of NaOH, stirring and mixing uniformly, then adding 6g of acrylamide, mixing uniformly, adding 0.06g of KPS initiator (potassium persulfate), heating to 50 ℃ in a water bath, stirring for 2h, then heating to 60 ℃, stirring for 5h at constant temperature, cooling to room temperature, adding 0.12g of cross-linking agent glutaraldehyde, stirring for 20min, and preparing 50g of 30 wt% ((6+3+ 3)/50), wherein the mass of the initiator and the cross-linking agent is small and can be ignored, and the same below) spinning solution C.

In the second step, the method specifically comprises the following steps:

(1) filling the spinning solution A into an injector A, and performing electrostatic spinning on the spinning solution A by taking non-woven fabrics as a substrate, wherein the electrostatic spinning method comprises the following steps: loading the spinning solution A into an injector A, adjusting the spinning parameter voltage to 15.8kv, setting the distance between the needle end of the injector A and a collector (the collector is covered with a non-woven fabric which is taken as a substrate) to be 15cm, the injection speed to be 100ul/min, the rotating speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50%, and the spinning time to be 15min, obtaining a hydrophilic layer 12 (namely, the nanofiber layer electrostatically spun by the spinning solution A is the hydrophilic layer 12), wherein an electron microscope image of the hydrophilic layer 12 is shown in FIG. 5;

(2) then replacing the injector A, filling the spinning solution B into the injector B, and carrying out electrostatic spinning on the spinning solution B by taking the hydrophilic layer 12 as a substrate, wherein the electrostatic spinning method comprises the following steps: adjusting the spinning parameter voltage to 10.9kv, the distance between the needle end of the injector B and the collector to be 15cm, the injection speed to be 100ul/min, the rotation speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50%, and the spinning time to be 15min, to obtain the hydrophobic layer 11 (namely, the nanofiber layer of the spinning solution B for electrostatic spinning is the hydrophobic layer 11, and at this time, both the hydrophilic layer 12 and the hydrophobic layer 11 are spun), which is located at the inner side of the hydrophilic layer 12, and the electron microscope image of the hydrophobic layer 11 is shown in FIG. 6;

(3) and (3) replacing the injector B, replacing the injector C with another injector C, injecting the spinning solution C, and carrying out electrostatic spinning on the spinning solution C by taking the hydrophobic layer 11 prepared in the step (2) as a substrate, wherein the electrostatic spinning method comprises the following steps: the spinning parameter voltage is adjusted to be 18.7kv, the distance between the needle end of the injector C and the collector is 15cm, the injection speed is 100ul/min, the rotation speed of the collector is 600rpm, the spinning temperature is 25 ℃, the humidity is 50%, and the spinning time is 15min, so that the water absorbing layer 13 positioned at the inner side of the hydrophobic layer 11 is obtained (namely, the nanofiber layer of the spinning solution C in electrostatic spinning is the water absorbing layer 13, and at this time, the hydrophilic layer 12, the hydrophobic layer 11 and the water absorbing layer 13 are all spun well).

(4) And (3) placing the three layers of nanofiber membranes (the hydrophilic layer 12, the hydrophobic layer 11 and the water absorption layer 13) prepared in the step (3) in an oven, and heating for 5 hours at 120 ℃.

The performance test results of the nanofiber film (i.e., bag body 1) prepared in this example were as follows:

the average fiber diameter of the hydrophobic layer 11 of the nanofiber membrane is 240nm, the hydrophobic angle is 148.4 degrees, as shown in figure 4, (close to super-hydrophobic 150 degrees), the average fiber diameter of the hydrophilic layer 12 is 456nm, the hydrophobic angle is 65 degrees, the average fiber diameter of the water absorbing layer 13 is 588nm, and the liquid absorption rate is 110; the moisture permeability of the nanofiber membrane is 11.8kg/m2/d, the water pressure resistance is 98.6kPa, and the generation quantity of negative ions at 25 ℃ is 79/cm ³ (negative ions present in the air).

Example 2

The first step specifically comprises the following steps:

i, preparing a spinning solution A, wherein the preparation of the spinning solution A comprises the following steps:

(1.1) adding 2g of hydrophilic modified silicon dioxide nano particles (the diameter is 20nm) into 85g of organic solvent N, N-Dimethylformamide (DMF), simultaneously adding 1g of tourmaline nano powder into the organic solvent, and ultrasonically dispersing for 2 h;

(1.2) adding 15g of Polyacrylonitrile (PAN) into the step (1.1), wherein the dissolving temperature is 70 ℃, mechanically stirring for 4 hours to dissolve the polyacrylonitrile in the organic solvent, standing for 12 hours to defoam after the polyacrylonitrile is completely dissolved, and preparing 15% of spinning solution A, wherein the viscosity of the spinning solution A is 1689mPa & s;

(2.1) dissolving 15g of hydrophobic polyvinylidene fluoride (PVDF) and 0.05g of Sodium Dodecyl Benzene Sulfonate (SDBS) in 85g of organic solvent N, N-Dimethylformamide (DMF), wherein the dissolving temperature is 80 ℃, mechanically stirring for 4h, standing for 12h for defoaming after complete dissolution, and preparing spinning solution B with the concentration of 15 wt%, wherein the viscosity of the spinning solution B is 1466mPa & s;

III, preparing a spinning solution C, comprising the following steps:

(3.1) mixing 6g of acrylic acid and deionized water, adding 3g of NaOH, stirring and mixing uniformly, then adding 6g of acrylamide, mixing uniformly, adding 0.06g of KPS initiator (potassium persulfate), heating to 50 ℃ in a water bath, stirring for 2h, then heating to 60 ℃, stirring for 5h at constant temperature, cooling to room temperature, adding 0.12g of cross-linking agent glutaraldehyde, and stirring for 10min to obtain 50g of 30 wt% spinning solution C.

In the second step, the method specifically comprises the following steps:

(1) filling the spinning solution A into an injector A, and performing electrostatic spinning on the spinning solution A by taking non-woven fabrics as a substrate, wherein the electrostatic spinning method comprises the following steps: loading the spinning solution A into an injector A, adjusting the spinning parameter voltage to 15.7kv, setting the distance between the needle end of the injector A and a collector (the collector is covered with a non-woven fabric which is taken as a substrate) to be 15cm, the injection speed to be 100ul/min, the rotating speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50 percent and the spinning time to be 15min, and obtaining a hydrophilic layer 12 (namely, the nano fiber layer of the spinning solution A in electrostatic spinning is the hydrophilic layer 12);

(2) then replacing the injector A, filling the spinning solution B into the injector B, and carrying out electrostatic spinning by taking the hydrophilic layer 12 as a substrate, wherein the electrostatic spinning method comprises the following steps: adjusting the spinning parameter voltage to 15.4kv, the distance between the needle end of the injector B and the collector to 15cm, the injection speed to 100ul/min, the rotation speed of the collector to 600rpm, the spinning temperature to 25 ℃, the humidity to 50%, and the spinning time to 15min, to obtain the hydrophobic layer 11 located inside the hydrophilic layer 12 (i.e. the nanofiber layer of the spinning solution B for electrostatic spinning is the hydrophobic layer 11, and at this time, both the hydrophilic layer 12 and the hydrophobic layer 11 are spun);

(3) and (3) replacing the injector B, replacing the injector C with another injector C, injecting a spinning solution C, and carrying out electrostatic spinning by taking the hydrophobic layer 11 prepared in the step (2) as a substrate, wherein the electrostatic spinning method comprises the following steps: the spinning parameter voltage is adjusted to be 19.8kv, the distance between the needle end of the injector C and the collector is 15cm, the injection speed is 100ul/min, the rotation speed of the collector is 600rpm, the spinning temperature is 25 ℃, the humidity is 50%, and the spinning time is 15min, so that the water absorbing layer 13 positioned at the inner side of the hydrophobic layer 11 is obtained (namely, the nanofiber layer of the spinning solution C in electrostatic spinning is the water absorbing layer 13, and at this time, the hydrophilic layer 12, the hydrophobic layer 11 and the water absorbing layer 13 are all spun well).

(4) The prepared three-layer nanofiber membrane (the hydrophilic layer 12, the hydrophobic layer 11 and the water-absorbing layer 13) is placed in an oven and heated at 180 ℃ for 2 h.

the average fiber diameter of the hydrophobic layer 11 of the nanofiber membrane is 467nm, the hydrophobic angle is 146.4 degrees, the average fiber diameter of the hydrophilic layer 12 is 464nm, and the hydrophobic angle is 70 degrees; the average fiber diameter of the water absorption layer 13 is 607nm, and the liquid absorption rate is up to 105; the moisture permeability of the nanofiber membrane is 10.9kg/m ² (d) water pressure resistance of 96.6kPa, and the number of negative ions generated at 25 ℃ is 468/cm ³ 。

Example 3

The first step specifically comprises the following steps:

(1.1) adding 2g of hydrophilic modified silicon dioxide nano particles (the diameter is 30nm) into 85g of organic solvent N, N-Dimethylformamide (DMF), simultaneously adding 2g of tourmaline nano powder into the organic solvent, and ultrasonically dispersing for 2 h;

(1.2) adding 15g of Polyacrylonitrile (PAN) into the step (1.1), wherein the dissolving temperature is 80 ℃, mechanically stirring for 4 hours to dissolve the polyacrylonitrile in the organic solvent, standing for 12 hours to defoam after the polyacrylonitrile is completely dissolved, and preparing 15 wt% of spinning solution A, wherein the viscosity of the spinning solution A is 1792mPa & s;

II, preparing a spinning solution B, wherein the preparation of the spinning solution B comprises the following steps:

(2.1) dissolving 20g of hydrophobic polyvinylidene fluoride (PVDF) and 0.05g of Sodium Dodecyl Benzene Sulfonate (SDBS) in 80g of organic solvent N, N-Dimethylformamide (DMF), wherein the dissolving temperature is 80 ℃, mechanically stirring for 4h, standing for 12h for defoaming after complete dissolution to prepare spinning solution B with the concentration of 20 wt%, and the viscosity of the spinning solution B is 1457mPa & s;

III, preparing a spinning solution C, comprising the following steps:

In the second step, the method specifically comprises the following steps:

(1) filling the spinning solution A into an injector A, and performing electrostatic spinning on the spinning solution A by taking non-woven fabrics as a substrate, wherein the electrostatic spinning method comprises the following steps: loading the spinning solution A into an injector A, adjusting the spinning parameter voltage to be 16.8kv, enabling the distance between the needle end of the injector A and a collector (the collector is covered with a non-woven fabric which is taken as a substrate) to be 15cm, the injection speed to be 100ul/min, the rotating speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50 percent and the spinning time to be 15min, and obtaining a hydrophilic layer 12 (namely, the nanofiber layer of the spinning solution A in electrostatic spinning is the hydrophilic layer 12);

(2) then replacing the injector A, filling the spinning solution B into the injector B, and carrying out electrostatic spinning by taking the hydrophilic layer 12 as a substrate, wherein the electrostatic spinning method comprises the following steps: adjusting the spinning parameter voltage to be 18.9kv, the distance between the needle end of the injector B and the collector to be 15cm, the injection speed to be 100ul/min, the rotation speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50% and the spinning time to be 15min to obtain the hydrophobic layer 11 positioned at the inner side of the hydrophilic layer 12 (namely, the nanofiber layer of the spinning solution B for electrostatic spinning is the hydrophobic layer 11, and at this time, both the hydrophilic layer 12 and the hydrophobic layer 11 are spun);

(3) and (3) replacing the injector B, replacing the injector C with another injector C, injecting a spinning solution C, and carrying out electrostatic spinning by taking the hydrophobic layer 11 prepared in the step (2) as a substrate, wherein the electrostatic spinning method comprises the following steps: the spinning parameter voltage is adjusted to be 19.9kv, the distance between the needle end of the injector C and the collector is 15cm, the injection speed is 100ul/min, the rotation speed of the collector is 600rpm, the spinning temperature is 25 ℃, the humidity is 50%, and the spinning time is 15min, so that the water absorbing layer 13 positioned at the inner side of the hydrophobic layer 11 is obtained (namely, the nanofiber layer of the spinning solution C in electrostatic spinning is the water absorbing layer 13, and at this time, the hydrophilic layer 12, the hydrophobic layer 11 and the water absorbing layer 13 are all spun well).

(4) The prepared three-layer nanofiber membrane (hydrophilic layer 12, hydrophobic layer 11 and water-absorbing layer 13) was placed in an oven and heated at 150 ℃ for 4 h.

the average fiber diameter of the hydrophobic layer 11 of the composite nanofiber membrane is 572nm, the hydrophobic angle is 143.8 degrees, the average fiber diameter of the hydrophilic layer 12 is 498nm, the hydrophobic angle is 69 degrees, the average fiber diameter of the water absorbing layer 13 is 679nm, and the liquid absorption rate reaches 112; the moisture permeability of the composite nanofiber membrane is 10.4kg/m ² (d) water pressure resistance of 96.9kPa, and the anion generation amount at 25 ℃ of 978/cm ³ 。

Example 4

The first step specifically comprises the following steps:

(1.1) adding 2g of hydrophilic modified silicon dioxide nano particles (the diameter is 40nm) into an organic solvent of 85g of N, N-Dimethylformamide (DMF), simultaneously adding 3g of tourmaline nano powder into the organic solvent, and ultrasonically dispersing for 2 h;

(1.2) adding 15g of Polyacrylonitrile (PAN) into the step (1.1), wherein the dissolving temperature is 70 ℃, mechanically stirring for 4h, standing for 12h for defoaming after complete dissolution, so that the polyacrylonitrile is dissolved in an organic solvent to prepare a 15 wt% spinning solution A, and the viscosity of the spinning solution A is 1792mPa & s;

(2.1) dissolving 15g of hydrophobic polyvinylidene fluoride (PVDF) and 0.05g of Sodium Dodecyl Benzene Sulfonate (SDBS) in 85g of organic solvent N, N-Dimethylformamide (DMF), wherein the dissolving temperature is 80 ℃, mechanically stirring for 4h, standing for 12h for defoaming after complete dissolution, and preparing 15 wt% spinning solution B, wherein the viscosity of the spinning solution B is 1645mPa & s;

III, preparing a spinning solution C, comprising the following steps:

(3.1) mixing 6g of acrylic acid and deionized water, adding 3g of NaOH, stirring and mixing uniformly, then adding 6g of acrylamide, mixing uniformly, adding 0.06g of KPS initiator (potassium persulfate), heating to 50 ℃ in a water bath, stirring for 2h, then heating to 60 ℃, stirring for 5h at constant temperature, cooling to room temperature, adding 0.12g of cross-linking agent glutaraldehyde, and stirring for 20min to obtain 50g of 30 wt% spinning solution C.

In the second step, the method specifically comprises the following steps:

(2) then replacing the injector B, filling the spinning solution B into the injector B, and carrying out electrostatic spinning by taking the hydrophilic layer 12 as a substrate, wherein the electrostatic spinning method comprises the following steps: adjusting the spinning parameter voltage to be 18.9kv, the distance between the needle end of the injector B and the collector to be 15cm, the injection speed to be 100ul/min, the rotation speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50% and the spinning time to be 15min to obtain the hydrophobic layer 11 positioned at the inner side of the hydrophilic layer 12 (namely, the nanofiber layer of the spinning solution B for electrostatic spinning is the hydrophobic layer 11, and at this time, both the hydrophilic layer 12 and the hydrophobic layer 11 are spun);

(3) and (3) replacing the injector B, replacing the injector C with another injector C, injecting a spinning solution C, and carrying out electrostatic spinning by taking the hydrophobic layer 11 prepared in the step (2) as a substrate, wherein the electrostatic spinning method comprises the following steps: the spinning parameter voltage is adjusted to be 18.9kv, the distance between the needle end of the injector C and the collector is 15cm, the injection speed is 100ul/min, the rotation speed of the collector is 600rpm, the spinning temperature is 25 ℃, the humidity is 50%, and the spinning time is 15min, so that the water absorbing layer 13 positioned at the inner side of the hydrophobic layer 11 is obtained (namely, the nanofiber layer of the spinning solution C in electrostatic spinning is the water absorbing layer 13, and at this time, the hydrophilic layer 12, the hydrophobic layer 11 and the water absorbing layer 13 are all spun well).

the average fiber diameter of the hydrophobic layer 11 of the composite nanofiber membrane is 477nm, the hydrophobic angle is 143.8 degrees, the average fiber diameter of the hydrophilic layer 12 is 545nm, the hydrophobic angle is 69 degrees, the average fiber diameter of the water absorbing layer 13 is 624nm, the liquid absorption rate is 99 degrees, and the moisture permeability of the composite nanofiber membrane is 10.4kg/m ² (d) a water pressure resistance of 96.9kPa and a negative ion generation amount of 1087/cm at 25 ℃ ³ 。

Example 5

The first step specifically comprises the following steps:

(1.1) adding 1g of hydrophilic modified silica nanoparticles (diameter of 30nm) to an organic solvent of N, N-Dimethylformamide (DMF);

(1.2) adding 5g of Polyacrylonitrile (PAN) into the step (1.1), wherein the dissolving temperature is 70 ℃, mechanically stirring for 4 hours to dissolve the polyacrylonitrile in the organic solvent, standing for 12 hours to defoam after the polyacrylonitrile is completely dissolved, and preparing a spinning solution A with the viscosity of 5 wt%, wherein the viscosity of the spinning solution A is 798mPa & s;

(2.1) dissolving 20g of hydrophobic polyvinylidene fluoride (PVDF) and 0.05g of Sodium Dodecyl Benzene Sulfonate (SDBS) in an organic solvent N, N-Dimethylformamide (DMF), wherein the dissolving temperature is 80 ℃, mechanically stirring for 4h, standing for 12h for defoaming after complete dissolution to prepare a spinning solution B with the concentration of 20 wt%, and the viscosity of the spinning solution B is 1957 mPas;

III, preparing a spinning solution C, comprising the following steps:

(3.1) mixing 8.8g of acrylic acid and deionized water, adding 2.2g of NaOH, stirring and mixing uniformly, then adding 8.8g of acrylamide, mixing uniformly, adding 0.176g of KPS initiator (potassium persulfate), heating to 50 ℃ in a water bath, stirring for 2h, heating to 60 ℃, stirring for 5h at constant temperature, cooling to room temperature, adding 0.88g of cross-linking agent glutaraldehyde, and stirring for 10-20 min to obtain 100ml of 20 wt% spinning solution C.

In the second step, the method specifically comprises the following steps:

(1) filling the spinning solution A into an injector A, and performing electrostatic spinning on the spinning solution A by taking non-woven fabrics as a substrate, wherein the electrostatic spinning method comprises the following steps: loading the spinning solution A into an injector, adjusting the spinning parameter voltage to 10.7kv, setting the distance between the needle end of the injector A and a collector (the collector is covered with a non-woven fabric which is taken as a substrate) to be 15cm, the injection speed to be 100ul/min, the rotating speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50 percent and the spinning time to be 15min, and obtaining a hydrophilic layer 12 (namely, the nanofiber layer of the spinning solution A in electrostatic spinning is the hydrophilic layer 12);

(3) and (3) replacing the injector B, replacing the injector C with another injector C, injecting a spinning solution C, and carrying out electrostatic spinning by taking the hydrophobic layer 11 prepared in the step (2) as a substrate, wherein the electrostatic spinning method comprises the following steps: the spinning parameter voltage is adjusted to be 20.8kv, the distance between the needle end of the injector C and the collector is 15cm, the injection speed is 100ul/min, the rotation speed of the collector is 600rpm, the spinning temperature is 25 ℃, the humidity is 50%, and the spinning time is 15min, so that the water absorbing layer 13 positioned at the inner side of the hydrophobic layer 11 is obtained (namely, the nanofiber layer of the spinning solution C in electrostatic spinning is the water absorbing layer 13, and at this time, the hydrophilic layer 12, the hydrophobic layer 11 and the water absorbing layer 13 are all spun well).

the average fiber diameter of the hydrophobic layer 11 of the composite nanofiber membrane is 581nm, the hydrophobic angle is 146.9 degrees, the average fiber diameter of the hydrophilic layer 12 is 367nm, the hydrophobic angle is 79 degrees, the average fiber diameter of the water absorbing layer 13 is 521nm, the liquid absorption rate is 107 degrees, the moisture permeability of the composite nanofiber membrane is 12.4kg/m2/d, the water pressure resistance is 86.9kPa, and the anion generation quantity at 25 ℃ is 68/cm ³ 。

Example 6

The first step specifically comprises the following steps:

(1.1) adding 1g of hydrophilic modified silica nanoparticles (diameter 30nm) to 79g of N, N-Dimethylformamide (DMF), an organic solvent;

(1.2) adding 20g of Polyacrylonitrile (PAN) into the step (1.1), wherein the dissolving temperature is 70 ℃, mechanically stirring for 4 hours to dissolve the polyacrylonitrile in the organic solvent, standing for 12 hours to defoam after the polyacrylonitrile is completely dissolved, and preparing a spinning solution A with the viscosity of 20 wt%, and 1970mPa & s of the spinning solution A;

(2.1) dissolving 20g of hydrophobic polyvinylidene fluoride (PVDF) and 0.05g of Sodium Dodecyl Benzene Sulfonate (SDBS) in an organic solvent N, N-Dimethylformamide (DMF), wherein the dissolving temperature is 80 ℃, mechanically stirring for 4h, standing for 12h for defoaming after complete dissolution to prepare a spinning solution B with the concentration of 20 wt%, and the viscosity of the spinning solution B is 1678 mPas;

III, preparing a spinning solution C, comprising the following steps:

(3.1) mixing 6g of acrylic acid and deionized water, adding 3g of NaOH, stirring and mixing uniformly, then adding 6g of acrylamide, mixing uniformly, adding 0.06g of KPS initiator (potassium persulfate), heating to 50 ℃ in a water bath, stirring for 2h, then heating to 60 ℃, stirring for 5h at constant temperature until the reaction is finished, cooling to room temperature, adding 0.12g of cross-linking agent glutaraldehyde, and stirring for 10-20 min to obtain 50g of 30 wt% spinning solution C.

In the second step, the method specifically comprises the following steps:

(1) filling the spinning solution A into an injector A, and performing electrostatic spinning on the spinning solution A by taking non-woven fabrics as a substrate, wherein the electrostatic spinning method comprises the following steps: loading the spinning solution A into an injector, adjusting the spinning parameter voltage to be 19.8kv, enabling the distance between the needle end of the injector A and a collector (the collector is covered with a piece of non-woven fabric which is taken as a substrate) to be 15cm, the injection speed to be 100ul/min, the rotating speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50 percent and the spinning time to be 15min, and obtaining a hydrophilic layer 12;

(2) then the injector is replaced, the spinning solution B is filled into the injector B, electrostatic spinning is carried out by taking the hydrophilic layer 12 as a substrate, and the electrostatic spinning method comprises the following steps: adjusting the spinning parameter voltage to be 16.9kv, the distance between the needle end of the injector B and the collector to be 15cm, the injection speed to be 100ul/min, the rotation speed of the collector to be 600rpm, the spinning temperature to be 25 ℃, the humidity to be 50% and the spinning time to be 15min to obtain the hydrophobic layer 11 positioned at the inner side of the hydrophilic layer 12 (namely, the nanofiber layer of the spinning solution B for electrostatic spinning is the hydrophobic layer 11, and at this time, the hydrophilic layer 12 and the hydrophobic layer 11 are both spun);

(3) and (3) replacing the injector B, replacing the injector C with another injector C, injecting a spinning solution C, and carrying out electrostatic spinning by taking the hydrophobic layer 11 prepared in the step (2) as a substrate, wherein the electrostatic spinning method comprises the following steps: the spinning parameter voltage is adjusted to be 19.1kv, the distance between the needle end of the injector and the collector is 15cm, the injection speed is 100ul/min, the rotating speed of the collector is 600rpm, the spinning temperature is 25 ℃, the humidity is 50%, and the spinning time is 15min, so that the water absorbing layer 13 positioned at the inner side of the hydrophobic layer 11 is obtained (namely, the nanofiber layer of the spinning solution C in electrostatic spinning is the water absorbing layer 13, and at this time, the hydrophilic layer 12, the hydrophobic layer 11 and the water absorbing layer 13 are all spun well).

the average fiber diameter of the hydrophobic layer 11 of the composite nanofiber membrane is 598nm, the hydrophobic angle is 133.8 degrees, the average fiber diameter of the hydrophilic layer 12 is 640nm, and the hydrophobic angle is 69 degrees; the average fiber diameter of the water absorption layer 13 is 654nm, the liquid absorption rate is 98, the moisture permeability of the composite nanofiber membrane is 10.4kg/m2/d, the water pressure resistance is 96.9kPa, and the anion generation quantity at 25 ℃ is 66/cm ³ 。

The performance test method of the nanofiber membrane in each example is as follows:

hydrophobic property of hydrophobic layer of nanofiber membrane

And testing the hydrophobic property of the blended film by adopting an OCA25 type contact angle measuring instrument. Dripping 2ul of water drops on the surface of the blended film, shooting by using a high-precision camera, automatically calculating a contact angle theta, wherein the larger the contact angle theta is, the stronger the hydrophobicity is, when theta is larger than 90 degrees and smaller than 150 degrees, the surface of the material has hydrophobicity, theta is larger than 150 degrees, and the surface of the material has super-hydrophobicity.

Moisture permeability test of nanofiber membrane

According to the test standard for moisture permeability of a fiber film, ASTM E96 standard, a moisture permeability tester model YG601 was used in the experiment. The moisture permeability of the fiber film is tested by adopting an inverted cup water evaporation method.

The operation steps are as follows: firstly, cutting the fiber film according to the shape of the moisture permeable cup, adding about 34g of distilled water into the moisture permeable cup, fixing the cut fiber film on the moisture permeable cup, and sealing the edge by using a sealing film. And finally, inversely placing the moisture permeable cup on a tray in a moisture permeable box, setting the temperature in the box to be 23 ℃ and the humidity to be 50%, closing the box body, starting testing and timing, taking out the moisture permeable cup after 1h, covering the moisture permeable cover, weighing the mass of the cup body, marking as m1, then placing the moisture permeable cup back into the moisture permeable box, repeating the previous operation after 1h, marking the mass as m2, substituting the mass into a formula, and calculating to obtain the moisture permeability WVT (Water Vapor Transmission) of the substance.

WVT-moisture permeability, kg/m2/d

t-test time, h

S-area of sample tested, m2

Third, waterproof performance test

Water pressure resistance test method:

fixing the fiber membrane in a test area under normal temperature and normal pressure, increasing water pressure at the rate of 6kPa/min until three small water beads (excluding the area within 3mm of the compression ring) appear on different areas of the fiber membrane, wherein the pressure value at the moment is the hydrostatic pressure value of the fiber membrane, namely the resistance of the fiber membrane to liquid water penetration, and the water resistance of the material is small, which indicates that the water resistance or the resistance to penetration of the material is not good. The test was carried out according to the national test standard GB/T4744-1997 with a sample area of 15X 15cm2, each sample was tested in triplicate and the average was taken as the final water pressure resistance value of the fibrous membrane.

And fourthly, testing the negative ion release amount of the composite nano-fiber by adopting an AIC-2 type air negative ion tester (ALP, USA), wherein the test method refers to SN/T2558.2-2011 'import and export functional textile test method, and the second part is negative ion content'.

Fifthly, the method for testing the liquid absorption rate of the water absorption layer comprises the following steps: referring to a test method of GB/T8939-. The formula is as follows:

wherein W1 is the mass of the sample and the tinfoil before water absorption, W2 is the mass of the sample and the tinfoil after water absorption, and W3 is the mass of the tinfoil after the fibers on the tinfoil paper are removed and the tinfoil is put into an oven to be dried for half an hour at 130 ℃.

Sixth, as shown in fig. 3, the electrostatic spinning apparatus for spinning the spinning solution A, B, C in the above embodiments includes an injector 3 (such injectors can be used for the injector a, the injector B, and the injector C), and a collector 4, where a distance between a needle end of the injector 3 and the collector 4 is D.

Claims

1. The utility model provides a moisture absorption package, includes the bag body (1) and locates drier (2) in the bag body (1), its characterized in that, the bag body (1) includes from interior to exterior in proper order superpose can supply water vapor to pass through and can not supply the hydrophilic layer (12) of water vapor with hydrophobic layer (11) that liquid water passes through, hydrophilic layer and hydrophobic layer (11) are the nanofiber layer of preparing through electrostatic spinning.

2. The absorbent packet of claim 1, wherein: the drying agent (2) is at least one of calcium chloride, magnesium chloride, lithium bromide, potassium acetate, sodium phosphate and sodium metaphosphate.

3. The absorbent packet of claim 1, wherein: the bag body (1) further comprises a water absorption layer (13) which expands after absorbing water and has smaller pores, the water absorption layer (13) is arranged on the inner side of the hydrophobic layer (11), and the water absorption layer (13) is also a nanofiber layer prepared through electrostatic spinning.

4. A method of making the absorbent packet of claim 1 or 2, wherein: the method comprises the following steps:

firstly, preparing spinning solution A and spinning solution B

secondly, preparing the nanofiber membrane, comprising the following steps:

(2) and then replacing the injector A, filling the spinning solution B into the injector B, and carrying out electrostatic spinning on the spinning solution B by taking the hydrophilic layer as a substrate to obtain a hydrophobic layer (11) positioned on the inner side of the hydrophilic layer.

5. The method of claim 4, wherein: the electrostatic spinning method in the step (1) comprises the following steps: filling the spinning solution A into an injector A, adjusting the voltage of spinning parameters to be 5-20kv, enabling the distance between the needle end of the injector A and a collector to be 5-15cm, arranging non-woven fabrics on the collector, enabling the injection speed to be 5-200ul/min, the rotating speed of the collector to be 300-3000rpm, the spinning temperature to be 20-30 ℃, the humidity to be 40-70% and the spinning time to be 5-20min, and obtaining the hydrophilic layer;

6. The method of claim 4, wherein: in the step (1.1) or (2.1), the organic solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide and acetone.

7. The method of claim 4, wherein: in the step (1.1), tourmaline nano powder is added into the organic solvent.

8. The method of claim 7, wherein: in the steps (1.1) and (1.2), the diameter of the nano particles is 10-40 nm, the mass ratio of the nano particles to the hydrophilic polymer is 1 (5-20), and the mass ratio of the tourmaline nano powder to the hydrophilic polymer is 1 (5-15).

9. The method of claim 4, wherein: in the step (2.1), a surfactant is further added into the organic solvent, wherein the surfactant is at least one of sodium dodecyl benzene sulfonate, cetyl trimethyl ammonium bromide, sodium dodecyl sulfate and cetyl trimethyl ammonium bromide.

10. The method of claim 9, wherein: the mass ratio of the surfactant to the polymer is 1 (100-400).

11. The method of claim 4, wherein: the bag body (1) further comprises a water absorption layer (13) which expands after absorbing water and has smaller pores, the water absorption layer (13) is arranged on the inner side of the hydrophobic layer (11), and the first step further comprises

III, preparing a spinning solution C, comprising the following steps:

The second step further comprises the following steps:

(3) and (3) replacing the injector B, replacing the injector C with another injector C, and injecting the spinning solution C, and carrying out electrostatic spinning on the spinning solution C by taking the hydrophobic layer (11) prepared in the step (2) as a substrate to obtain a water absorbing layer (13) positioned on the inner side of the hydrophobic layer (11).

12. The method of claim 11, wherein: and the second step also comprises a step (4) of heating the prepared three-layer nanofiber membrane at 120-180 ℃ for 2-5 h.

13. The method of claim 11, wherein: the mass ratio of the acrylic acid to the acrylamide to the NaOH is (2-4) to 1, the initiator accounts for 0.5-1.0% of the total mass of the acrylic acid and the acrylamide, and the glutaraldehyde accounts for 1-5% of the total mass of the acrylic acid and the acrylamide.

14. The method of claim 11, wherein: in the step (3), the electrostatic spinning method comprises the following steps: adjusting the spinning parameter voltage to 5-20kv, the distance between the needle end of the injector C and the collector to 5-15cm, the injection speed to 5-200ul/min, the rotation speed of the collector to 300-.