CN109367165B - LiNbO3Anti-haze window screen with/PAN (polyacrylonitrile) composite nanofiber electret and preparation method of anti-haze window screen - Google Patents

Abstract

The invention discloses a LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen with high-efficiency filtration performance and a preparation method thereof. The invention includes three-layer fiber membranes, and the three-layer fiber membrane includes a core layer, a base layer and a base layer. And the upper layer, the core layer is LiNbO ₃ /PAN composite nanofibers, the substrate is silver-plated polymer network structure, the upper layer is black polyester non-woven fabric, LiNbO ₃ /PAN composite nanofibers are adhered to the plating by electrospinning. The silver-plated network structure with LiNbO ₃ /PAN composite nanofibers adhered to the polymer network structure of silver was obtained, and the silver-plated network structure with LiNbO ₃ /PAN composite nanofibers adhered to the black polyester non-woven fabric by ultrasonic bonding. on fabric. The invention prepares the PAN/LiNbO ₃ composite nanofiber by electrospinning, the average diameter is about 100 nm, the strength is high, the filtering effect is good, and it is easy to adhere to the polymer non-woven fabric.

Description

A LiNbO3/PAN composite nanofiber electret anti-fog and haze window screen and its preparation method

technical field

The invention relates to the field of air filtration, in particular to a LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen and a preparation method thereof, which are applied to filtering fine particles such as PM2.5.

Background technique

Many people know what smog is, but they do not have a clear understanding of why smog can cause great harm to the body. It should be known that smog is mainly composed of air particle pollutants (particulate matter, PM). The aerodynamic diameter of PM in the environment is about 0.001-100um, and the most harmful to the respiratory tract is the aerodynamic diameter ≤ 10um. The main sources of inhalable particulate matter PM10 and ≤2.5um fine particulate matter PM2.5 are dust, construction debris and dye burning waste, industrial air emissions, etc. They carry harmful fungi, bacteria, Viruses and even harmful gases such as sulfur dioxide, carbon monoxide, and carbon dioxide. PM10, PM2.5 and other particulate matter in the haze carry irritating and harmful gases, bacteria, viruses, etc., and enter the respiratory system with breathing. First, they stimulate the respiratory mucosa and produce an inflammatory response; secondly, heavy metals and fine dust will be deposited in the throat, The bronchi, terminal bronchioles and alveoli even enter the body, affecting the respiratory system and physical health; the last winter is the high incidence season of respiratory infectious diseases, and the virus is mostly transmitted through the respiratory tract. Virus transmission provides extremely convenient conditions, so the prevalence of respiratory infectious diseases such as influenza, mumps, chickenpox, etc. remains high. Ordinary window screens have no anti-haze function, and electret electrostatic nanofiber anti-haze screens have received widespread attention because their PM2.5 filtration efficiency can reach more than 85%.

Electret electrostatic nanofiber materials have the advantages of high filtration efficiency, low resistance, and long electret time, which make them stand out among all air filtration materials. Electret filtration materials have become a research hotspot in the field of filtration. Traditional fiber filter materials rely on the mechanical action mechanism of fibers to intercept particles, but electret electrostatic nanofiber filter materials use electrostatic adsorption to capture particles. This makes its filtration efficiency greatly improved compared to traditional filter materials.

The polar body filter material is made by non-woven dry forming process, such as melt blowing method. In the dry forming process, the fibers can be charged by a number of methods. At present, the methods of electrostatic electret mainly include electrospinning method, corona discharge method, triboelectric method, thermal polarization method, low-energy electron beam bombardment method, fibrillation tearing and so on. Compared with the existing electret fiber preparation technology, electrospinning technology can use the action of high-voltage electric field to inject charges in situ during the process of the evolution of polymer materials from fluid solutions to solid fibers, so that the energy of charge injection can be improved. Compared with the traditional electret technology, it is expected to improve the stability of the electret effect after the fiber is formed, and it is also a mature process that can prepare nanofibers.

Lithium niobate (LiNbO ₃ , LN for short) crystal is a colorless or light yellow transparent crystal with a melting point of 1240°C and a density of 4.70X10 ³ kg·m ^-3 . The Mohs hardness is 6, the ferroelectric phase structure belongs to a point group of 3m, and the two paraelectric phase structure belongs to a point group of 3m. LN crystal integrates various effects such as electro-optical, acousto-optical, photoelastic, nonlinear, and photorefractive. This is rare in intraocular lenses. The growth of LN crystal has good feasibility, such as abundant raw material sources, low price, easy to grow into large crystals, and can also show various special energies through different doping methods. Therefore, L/N crystal is the crystal with the most optical properties and the best comprehensive index found so far.

With the update and development of electrospinning technology, more than 100 kinds of polymers can be used to prepare nanofibers. Among them, polyacrylonitrile (PAN) is one of the most commonly used polymer raw materials in electrospinning process. Polyacrylonitrile fibers refer to fibers spun from polyacrylonitrile or fibers spun from copolymers containing more than 85% of acrylonitrile. In 2000, the output of polyacrylonitrile fiber in the world was 2.6685Mt, and the output of polyacrylonitrile fiber in my country was 473.7kt. In the electrospinning process, the nanofiber membrane prepared by it has high strength, good stretchability and good dielectric properties, so it has a relatively broad application potential in air filtration.

SUMMARY OF THE INVENTION

In view of the above technical problems, the present invention provides a LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen with high-efficiency filtration performance and a preparation method thereof. LiNbO ₃ /PAN composite nanofiber material is charged and has the advantages of low flow resistance, high efficiency, high air permeability, long life, high dust collection ability and energy saving. It not only has excellent filtration performance, but also inhibits common bacteria. and killing effect. The combination of electrospinning technology and electret greatly improves the material's ability to absorb fine particles, so that the PM2.5 filtration efficiency of this anti-haze window screen can reach more than 85%. The substrate is silver-plated PP melt-blown non-woven fabric, so that the obtained anti-fog window screen has the advantages of high strength, high filtration efficiency, good light transmission, and good air permeability.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme: a LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen, comprising three layers of fiber membranes, the three layers of fiber membranes include a core layer, a base and a The upper layer, the core layer is LiNbO ₃ /PAN composite nanofibers, the base is a 500-700 mesh silver-plated polymer mesh structure, the upper layer is 50-150 mesh black polyester non-woven fabric, LiNbO ₃ /PAN composite nanofibers Adhering to the silver-coated polymer network by electrospinning to obtain a silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers attached, and a silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers attached Bonded to black polyester non-woven fabric by ultrasonic.

The LiNbO ₃ /PAN composite nanofibers are composited by LiNbO ₃ nanocrystals and PAN nanofibers, wherein the mass ratio of LiNbO ₃ nanocrystals and PAN nanofibers is (1-5):(1000-3000). The LiNbO ₃ nanocrystalline particles have a single-domain ferroelectric phase single-crystal structure.

The particle size of the LiNbO ₃ nanocrystal particles is 20-50 nm, the diameter of the LiNbO ₃ /PAN composite nanofiber fiber is 100-200 nm, and the porosity is 0.20-0.85 cm ³ /g.

The preparation method of the LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen includes the following steps: (1) preparing LiNbO ₃ nanocrystals with a particle size of 20-50 nm;

(2) Weigh 0.01-0.05 g of LiNbO ₃ nanocrystals obtained in step (1), put it into a clean glass bottle, then weigh 30-50 g of DMF into the corresponding glass bottle and stir with a magnetic stirrer Obtained LiNbO ₃ /DMF dispersion;

(3) Weigh 10-30 g of PAN powder and add it to the LiNbO ₃ /DMF dispersion obtained in step (2) to prepare a PAN solution; heat the PAN solution to 60-80 ˚C in a water bath and stir vigorously for 15-24 h, until the polymer is completely dissolved and dispersed uniformly to obtain a mixed solution;

(4) using the mixed solution obtained in step (3) to perform electrospinning, and spinning it onto the silver-plated polymer network structure to obtain a silver-plated network structure adhered to the LiNbO ₃ /PAN composite nanofibers;

(5) The LiNbO ₃ /PAN composite nanofiber electret is obtained by bonding the silver-plated mesh structure with the LiNbO ₃ /PAN composite nanofibers obtained in step (4) and the black polyester non-woven fabric together by ultrasonic waves Anti-smog window screens.

The preparation of LiNbO ₃ nanocrystals in step (1) includes the following steps: a. Pour the weighed Li ₂ CO ₃ and Nb ₂ O ₅ into a beaker to prepare a mixed solution of Li ₂ CO ₃ and Nb ₂ O ₅ , The molar mass ratio of Li ₂ CO ₃ and Nb ₂ O ₅ is (1.0-5.0):(1.0-4.0), and the molar concentration of Li ₂ CO ₃ is 0.1-1.0 mol/L;

b. Add a surfactant (SDS) with a mass concentration of 0.1%-0.5% to the mixed solution prepared in step (1), stir on a magnetic stirrer for 10-60 min and pour it into the reaction kettle, and the reaction kettle is sealed After heating, the reaction product is obtained. The heating temperature of the reaction kettle is 200-300 °C, and the heating time is 12-24 h; the surfactant (SDS) is sodium dodecyl sulfate;

c. Take out the reaction product obtained in step (2) and wash with distilled water and absolute ethanol for 2-5 times respectively; put the washed product into a freeze-drying box, and dry it at minus 60-80 ℃ for 2-5 times h, LiNbO3 nanocrystals _were obtained.

In step (2), in order to ensure that the LiNbO ₃ nanocrystalline particles can be uniformly dispersed in the DMF, an ultrasonic cleaning device is used for ultrasonic dispersion treatment for 30-60 min.

The silver-plated polymer network structure in step (4) is PP/nylon/polyester, and the number of pores of the silver-plated polymer network structure is 500-700 meshes.

When the electrospinning device in step (4) is working, the voltage of the high-voltage generator is 0-80 kV; the distance from the nozzle to the receiving base cloth is 10-15 cm; the diameter of the nozzle is 0.1-10 cm; The flow rate of spinning solution is 0.5-3.0 mL/h; the receiving time is 0.5-15 min.

The LiNbO ₃ /PAN composite nanofibers obtained in step (4) have a diameter of 100-200 nm, a porosity of 0.20-0.85 cm ³ /g, and an areal density of 1.25-5.0 g/m ² .

The number of holes of the black polyester non-woven fabric described in step (5) is 50-150 meshes.

The advantages of the invention are: (1) PAN/LiNbO ₃ composite nanofibers are prepared by electrospinning, the average diameter is about 100 nm, the strength is high, the filtering effect is good, and it is easy to adhere to the polymer non-woven fabric.

(2) Combining the electrospinning process with electret, the filtration efficiency of the material for fine particles is greatly increased by electrostatic adsorption, and the addition of electret can make the fiber charge for a long time and the filtration effect is good.

(3) The prepared composite nanofibers were spun on silver-coated polymer non-woven fabrics and bonded with black polyester by ultrasonic waves, and the anti-fog of electret electrostatic nanofibers with high filtration efficiency, low air resistance and good light transmittance was obtained. Haze screen. The whole process is simple, easy to operate, can be mass-produced, and provides convenient conditions for preventing haze.

Description of drawings

Fig. 1 is the field emission electron microscope picture of the LiNbO ₃ /PAN composite nanofiber membrane prepared by the present invention;

Fig. ₂ is the LiNbO nanoparticle prepared by the hydrothermal method of the present invention;

Figure 3 is the actual picture of the LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

A LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen, comprising three layers of fiber films, the three layers of fiber films include a core layer, a base and an upper layer, and the core layer is LiNbO ₃ /PAN composite nanometer Fiber, the base is a 500-mesh silver-plated polymer network structure, the upper layer is a 50-mesh black polyester non-woven fabric, and the LiNbO ₃ /PAN composite nanofibers are adhered to the silver-plated polymer network structure by electrospinning. The silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers attached, and the silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers adhered to black polyester non-woven fabric by ultrasonic bonding.

The LiNbO ₃ /PAN composite nanofibers are composited by LiNbO ₃ nanocrystals and PAN nanofibers. The LiNbO ₃ nanocrystalline particles have a single-domain ferroelectric phase single-crystal structure. The particle size of the LiNbO ₃ nanocrystal particles is 20-50 nm, the diameter of the LiNbO ₃ /PAN composite nanofiber fiber is 100-200 nm, and the porosity is 0.20-0.85 cm ³ /g.

The preparation method of the LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen includes the following steps: (1) preparing LiNbO ₃ nanocrystals: including the following steps: a. The weighed Li ₂ CO ₃ and Pour _Nb2O5 into a beaker to prepare a mixed solution _{of Li2CO3} and _Nb2O5 , the _molar mass ratio _{of Li2CO3} and _Nb2O5 is 1.0 _: 1.1, and the molar concentration _{of Li2CO3} is _0.1mol /L;

b. Add a surfactant (SDS) with a mass concentration of 0.1% to the mixed solution prepared in step (1), stir on a magnetic stirrer for 20 min, and pour it into the reaction kettle. After the reaction kettle is sealed, the reaction product is obtained by heating, The heating temperature of the reaction kettle was 220 °C, and the heating time was 12 h; the surfactant (SDS) was sodium dodecyl sulfate;

c. Take out the reaction product obtained in step (2), and wash it twice with distilled water and absolute ethanol respectively; put the washed product into a freeze-drying box, and dry it at minus 50 °C for 2 hours to obtain a particle size of 20 nm _LiNbO3 nanocrystals.

(2) Weigh 0.01 g of LiNbO ₃ nanocrystals obtained in step (1), put it into a clean glass bottle, then weigh 30 g of DMF and add it to the corresponding glass bottle and stir with a magnetic stirrer to obtain LiNbO ₃ /DMF dispersion; in order to ensure that the LiNbO ₃ nanocrystalline particles can be uniformly dispersed in DMF, an ultrasonic cleaner was used for ultrasonic dispersion treatment for 30min.

(3) 10 g of PAN powder was weighed and added to the LiNbO ₃ /DMF dispersion obtained in step (2) to prepare a PAN solution; the PAN solution was heated to 60 ˚C in a water bath and stirred vigorously for 15 h until the polymer was completely Dissolve and disperse uniformly to obtain a mixed solution;

(4) using the mixed solution obtained in step (3) to perform electrospinning, and spinning it onto the silver-plated polymer network structure to obtain a silver-plated network structure adhered to the LiNbO ₃ /PAN composite nanofibers; The silver-plated polymer network structure is polyester, and the number of holes of the silver-plated polymer network structure is 500 meshes; when the electrospinning device works, the voltage of the high-voltage generator is 20 kV; The distance of the base cloth is 10 cm; the diameter of the nozzle is 0.5 cm; the flow rate of the sprayed electrospinning solution is 0.5 mL/h; the receiving time is 1 min; the diameter of the LiNbO ₃ /PAN composite nanofibers obtained in step (4) is 100 nm , the porosity is 0.25 cm ³ /g, and the areal density is 1.3 g/m ² .

(5) The LiNbO ₃ /PAN composite nanofiber electret is obtained by bonding the silver-plated mesh structure with the LiNbO ₃ /PAN composite nanofibers obtained in step (4) and the black polyester non-woven fabric together by ultrasonic waves Anti-smog window screens. The number of holes of the black polyester non-woven fabric is 50 meshes.

Example 2

A LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen, comprising three layers of fiber films, the three layers of fiber films include a core layer, a base and an upper layer, and the core layer is LiNbO ₃ /PAN composite nanometer Fiber, the base is a 550 mesh silver-plated polymer network structure, the upper layer is a 80-mesh black polyester non-woven fabric, and the LiNbO ₃ /PAN composite nanofibers are adhered to the silver-plated polymer network structure by electrospinning. The silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers attached, and the silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers adhered to black polyester non-woven fabric by ultrasonic bonding.

A preparation method of LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen, comprising the following steps: (1) preparing LiNbO ₃ nanocrystals: comprising the following steps: a. adding weighed Li ₂ CO ₃ and Nb Pour 2O5 into a beaker to prepare a mixed solution _{of Li2CO3} and _Nb2O5 , the molar mass ratio _{of Li2CO3} and _Nb2O5 is _{1.5 : 2} , and the molar concentration _{of Li2CO3} is _0.3mol / L;

b. Add surfactant (SDS) with a mass concentration of 0.2% to the mixed solution prepared in step (1), stir on a magnetic stirrer for 50 min and pour it into the reaction kettle, seal the reaction kettle and heat to obtain the reaction product , the heating temperature of the reaction kettle is 240 ℃, and the heating time is 14 h; the surfactant (SDS) is sodium dodecyl sulfate;

c. Take out the reaction product obtained in step (2), and wash it with distilled water and absolute ethanol for 3 times respectively; put the washed product into a freeze-drying box, and dry it at minus 60 °C for 3 h to obtain a particle size of ₃₀ nm LiNbO3 nanocrystals. .

(2) Weigh 0.02 g of LiNbO ₃ nanocrystals obtained in step (1), put it into a clean glass bottle, then weigh 40 g of DMF and add it to the corresponding glass bottle and stir with a magnetic stirrer to obtain LiNbO ₃ / DMF dispersion; in order to ensure that the LiNbO ₃ nanocrystal particles can be uniformly dispersed in DMF, an ultrasonic cleaner was used for ultrasonic dispersion treatment for 40 min.

(3) Weigh 15 g of PAN powder and add it to the LiNbO ₃ /DMF dispersion obtained in step (2) to prepare a PAN solution; heat the PAN solution to 70°C in a water bath, and stir vigorously for 20 hours until the polymer is completely dissolved And disperse uniformly to obtain a mixed solution;

(4) using the mixed solution obtained in step (3) to perform electrospinning, and spinning it onto the silver-plated polymer network structure to obtain a silver-plated network structure adhered to the LiNbO ₃ /PAN composite nanofibers; The silver-plated polymer network structure is PP, and the number of holes of the silver-plated polymer network structure is 550 meshes; when the electrospinning device is working, the voltage of the high-voltage generator is 30kV; The distance of the cloth is 11 cm; the diameter of the nozzle is 1 cm; the flow rate of the sprayed electrospinning solution is 1 mL/h; the receiving time is 2 min; the diameter of the LiNbO ₃ /PAN composite nanofibers obtained in step (4) is 120 nm, The porosity was 0.30 cm ³ /g, and the areal density was 2.0 g/m ² .

(5) The LiNbO ₃ /PAN composite nanofiber electret is obtained by bonding the silver-plated mesh structure with the LiNbO ₃ /PAN composite nanofibers obtained in step (4) and the black polyester non-woven fabric together by ultrasonic waves Anti-smog window screens. The number of holes of the black polyester non-woven fabric is 80 meshes.

Example 3

A LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen, comprising three layers of fiber films, the three layers of fiber films include a core layer, a base and an upper layer, and the core layer is LiNbO ₃ /PAN composite nanometer Fiber, the base is a 600-mesh silver-plated polymer network structure, the upper layer is a 120-mesh black polyester non-woven fabric, and the LiNbO ₃ /PAN composite nanofibers are adhered to the silver-plated polymer network structure by electrospinning. The silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers attached, and the silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers adhered to black polyester non-woven fabric by ultrasonic bonding.

The preparation method of the LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen includes the following steps: (1) preparing LiNbO ₃ nanocrystals: including the following steps: a. The weighed Li ₂ CO ₃ and Pour _Nb2O5 into a beaker to prepare a mixed solution _{of Li2CO3} and _Nb2O5 , the molar mass ratio of _Li2CO3 and _Nb2O5 is _{3 : 2} , and the molar concentration _{of Li2CO3} is _0.5mol /L;

b. Add a surfactant (SDS) with a mass concentration of 0.3% to the mixed solution prepared in step (1), stir on a magnetic stirrer for 30 min and pour it into the reaction kettle, and heat the reaction kettle after sealing to obtain the reaction product, The heating temperature of the reaction kettle is 260 °C, and the heating time is 18 h; the surfactant (SDS) is sodium dodecyl sulfate;

c. Take out the reaction product obtained in step (2), and wash it with distilled water and absolute ethanol for 3 times respectively; put the washed product into a freeze-drying box, and dry it at minus 70 ° C for 4 hours to obtain a particle size of 40 nm _LiNbO3 nanocrystals. .

(2) Weigh 0.03 g of LiNbO ₃ nanocrystals obtained in step (1), put it into a clean glass bottle, then weigh 45 g of DMF and add it to the corresponding glass bottle and stir with a magnetic stirrer to obtain LiNbO ₃ /DMF dispersion; in order to ensure that the LiNbO ₃ nanocrystalline particles can be uniformly dispersed in DMF, an ultrasonic cleaner was used for ultrasonic dispersion treatment for 50 min.

(3) Weigh 20 g of PAN powder and add it to the LiNbO ₃ /DMF dispersion obtained in step (2) to prepare a PAN solution; heat the PAN solution to 70°C with a water bath, and stir vigorously for 20 h until the polymer is completely dissolved And disperse uniformly to obtain a mixed solution;

(4) using the mixed solution obtained in step (3) to perform electrospinning, and spinning it onto the silver-plated polymer network structure to obtain a silver-plated network structure adhered to the LiNbO ₃ /PAN composite nanofibers; The silver-plated polymer network structure is nylon, and the number of holes of the silver-plated polymer network structure is 600 meshes; when the electrospinning device works, the voltage of the high-voltage generator is 30 kV; The distance of the base cloth is 13 cm; the diameter of the nozzle is 6.5 cm; the flow rate of the sprayed electrospinning solution is 2 mL/h; the receiving time is 10 min; the diameter of the LiNbO ₃ /PAN composite nanofibers obtained in step (4) is 160 nm, The porosity was 0.5 cm ³ /g, and the areal density was 3.2 g/m ² .

(5) The LiNbO ₃ /PAN composite nanofiber electret is obtained by bonding the silver-plated mesh structure with the LiNbO ₃ /PAN composite nanofibers obtained in step (4) and the black polyester non-woven fabric together by ultrasonic waves Anti-smog window screens. The number of holes of the black polyester non-woven fabric is 120 meshes.

Example 4

A LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen, comprising three layers of fiber films, the three layers of fiber films include a core layer, a base and an upper layer, and the core layer is LiNbO ₃ /PAN composite nanometer Fiber, the base is a 700-mesh silver-plated polymer network structure, the upper layer is a 150-mesh black polyester non-woven fabric, and the LiNbO ₃ /PAN composite nanofibers are adhered to the silver-plated polymer network structure by electrospinning. The silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers attached, and the silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers adhered to black polyester non-woven fabric by ultrasonic bonding.

The preparation method of the LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen includes the following steps: (1) preparing LiNbO ₃ nanocrystals: including the following steps: a. The weighed Li ₂ CO ₃ and Pour Nb ₂ O ₅ into a beaker to prepare a mixed solution of Li ₂ CO ₃ and Nb ₂ O ₅ , the molar mass ratio of Li ₂ CO ₃ and Nb ₂ O ₅ is 5.0: 4.0, and the molar concentration of Li ₂ CO ₃ is 1.0 mol /L;

b. Add a surface active agent (SDS) with a mass concentration of -0.5% to the mixed solution prepared in step (1), stir on a magnetic stirrer for 60 min, pour it into the reaction kettle, and heat the reaction kettle after sealing to obtain the reaction. The product, the heating temperature of the reaction kettle is 300 ℃, and the heating time is 24 h; the surfactant (SDS) is sodium dodecyl sulfate;

c. Take out the reaction product obtained in step (2), and wash it with distilled water and absolute ethanol for 5 times respectively; put the washed product into a freeze-drying box, and dry it at minus 80 °C for 5 h to obtain a particle size of 50 nm _LiNbO3 nanocrystals. .

(2) Weigh 0.05 g of LiNbO ₃ nanocrystals obtained in step (1), put it into a clean glass bottle, then weigh 50 g of DMF and add it to the corresponding glass bottle and stir with a magnetic stirrer to obtain LiNbO ₃ /DMF dispersion; in order to ensure that the LiNbO ₃ nanocrystal particles can be uniformly dispersed in DMF, an ultrasonic cleaner was used for ultrasonic dispersion treatment for 60 min.

(3) 30 g of PAN powder was weighed and added to the LiNbO ₃ /DMF dispersion obtained in step (2) to prepare a PAN solution; the PAN solution was heated to 80 ˚C in a water bath and stirred vigorously for 24 h until the polymer was completely Dissolve and disperse uniformly to obtain a mixed solution;

(4) using the mixed solution obtained in step (3) to perform electrospinning, and spinning it onto the silver-plated polymer network structure to obtain a silver-plated network structure adhered to the LiNbO ₃ /PAN composite nanofibers; The silver-plated polymer network structure is nylon, and the number of holes of the silver-plated polymer network structure is 700 meshes; when the electrospinning device works, the voltage of the high-voltage generator is 50 kV; The distance of the base cloth is 15 cm; the diameter of the nozzle is 10 cm; the flow rate of the sprayed electrospinning solution is 3.0 mL/h; the receiving time is 15 min; the diameter of the LiNbO ₃ /PAN composite nanofibers obtained in step (4) is 200 nm , the porosity is 5.0 cm ³ /g, and the areal density is 5.0 g/m ² .

(5) The LiNbO ₃ /PAN composite nanofiber electret is obtained by bonding the silver-plated mesh structure with the LiNbO ₃ /PAN composite nanofibers obtained in step (4) and the black polyester non-woven fabric together by ultrasonic waves Anti-smog window screens. The number of holes of the black polyester non-woven fabric is 150 meshes.

Example 5

A LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen, comprising three layers of fiber films, the three layers of fiber films include a core layer, a base and an upper layer, and the core layer is LiNbO ₃ /PAN composite nanometer Fiber, the base is a 500-mesh silver-plated polymer network structure, the upper layer is a 150-mesh black polyester non-woven fabric, and the LiNbO ₃ /PAN composite nanofibers are adhered to the silver-plated polymer network structure by electrospinning. The silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers attached, and the silver-coated mesh structure with LiNbO ₃ /PAN composite nanofibers adhered to black polyester non-woven fabric by ultrasonic bonding.

The preparation method of the LiNbO ₃ /PAN composite nanofiber electret anti-haze window screen includes the following steps: (1) preparing LiNbO ₃ nanocrystals: including the following steps: a. The weighed Li ₂ CO ₃ and Pour Nb ₂ O ₅ into a beaker to prepare a mixed solution of Li ₂ CO ₃ and Nb ₂ O ₅ , the molar mass ratio of Li ₂ CO ₃ and Nb ₂ O ₅ is 1.0: 4.0, and the molar concentration of Li ₂ CO ₃ is 1.0 mol /L;

b. Add a surfactant (SDS) with a mass concentration of 0.5% to the mixed solution prepared in step (1), stir on a magnetic stirrer for 60 min, and pour it into the reaction kettle. The reaction kettle is sealed and heated to obtain the reaction product , the heating temperature of the reaction kettle is 300 ℃, and the heating time is 24 h; the surfactant (SDS) is sodium dodecyl sulfate;

c. Take out the reaction product obtained in step (2), and wash it with distilled water and absolute ethanol for 5 times respectively; put the washed product into a freeze-drying box, and dry it at minus 80 °C for 5 h to obtain a particle size of 60 nm _LiNbO3 nanocrystals.

(2) Weigh 0.05 g of LiNbO ₃ nanocrystals obtained in step (1), put it into a clean glass bottle, then weigh 30 g of DMF and add it to the corresponding glass bottle and stir with a magnetic stirrer to obtain LiNbO ₃ /DMF dispersion; in order to ensure that the LiNbO ₃ nanocrystal particles can be uniformly dispersed in DMF, an ultrasonic cleaner was used for ultrasonic dispersion treatment for 30 min.

(3) Weigh 10-30 g of PAN powder and add it to the LiNbO ₃ /DMF dispersion obtained in step (2) to prepare a PAN solution; heat the PAN solution to 60 ˚C in a water bath and stir vigorously for 15 h until the polymer Completely dissolve and disperse uniformly to obtain a mixed solution;

(4) using the mixed solution obtained in step (3) to perform electrospinning, and spinning it onto the silver-plated polymer network structure to obtain a silver-plated network structure adhered to the LiNbO ₃ /PAN composite nanofibers; The silver-plated polymer network structure is PP/nylon/polyester, and the number of holes of the silver-plated polymer network structure is 500 meshes; when the electrospinning device is working, the voltage of the high-voltage generator is 80 kV; the nozzle is The distance to the receiving base cloth is 15 cm; the diameter of the nozzle is 10 cm; the flow rate of the sprayed electrospinning solution is 3.0 mL/h; the receiving time is 15 min; the LiNbO ₃ /PAN composite nanofibers obtained in step (4) The diameter is 200 nm, the porosity is 0.85 cm ³ /g, and the areal density is 5.0 g/m ² .

(5) The LiNbO ₃ /PAN composite nanofiber electret is obtained by bonding the silver-plated mesh structure with the LiNbO ₃ /PAN composite nanofibers obtained in step (4) and the black polyester non-woven fabric together by ultrasonic waves Anti-smog window screens. The number of holes of the black polyester non-woven fabric is 150 meshes.

Claims (7)

1. LiNbO₃The preparation method of the/PAN composite nanofiber electret anti-haze window screen is characterized by comprising the following steps of: the method comprises the following steps: (1) preparing LiNbO with the grain diameter of 20-50 nm₃A nanocrystal;

(2) weighing the LiNbO obtained in the step (1)₃Adding 0.01-0.05 g of nano crystal into a clean glass bottle, weighing 30-50 g of DMF, adding into the corresponding glass bottle, and stirring with a magnetic stirrer to obtain LiNbO₃A DMF dispersion;

(3) 10-30 g of PAN powder was weighed and added to the LiNbO obtained in step (2)₃Preparing a PAN solution from a DMF dispersion liquid; heating the PAN solution to 60-80 ℃ in a water bath kettle, and violently stirring for 15-24 h until the polymer is completely dissolved and uniformly dispersed to prepare a mixed solution;

(4) carrying out electrostatic spinning by using the mixed solution obtained in the step (3), and spinning the mixed solution to a silver-plated high-molecular net structure to obtain the LiNbO adhered with the mixed solution₃A silver plated network of PAN composite nanofibers;

(5) the LiNbO adhered obtained in the step (4)₃The silver-plated net structure of the PAN composite nano fiber and the black polyester non-woven fabric are bonded together through ultrasonic wave to obtain LiNbO₃the/PAN composite nanofiber electret anti-haze window screen;

the LiNbO₃The anti-haze window screen comprises three layers of fiber films, wherein each three layer of fiber film comprises a core layer, a substrate and an upper layer, and the core layer is LiNbO₃The PAN composite nano fiber has a substrate of 500-mesh and 700-mesh silver-plated polymer mesh structure and an upper layer of 50-150-mesh black polyester non-woven fabric or LiNbO₃the/PAN composite nano fiber is adhered to a silver-plated high-molecular reticular structure through electrostatic spinning to obtain LiNbO adhered to the silver-plated high-molecular reticular structure₃Silver-plated net structure of/PAN composite nanofiber with LiNbO adhered thereto₃The silver-plated net structure of the/PAN composite nano fiber is bonded on the black polyester non-woven fabric through ultrasonic waves.

2. The LiNbO of claim 1, wherein the LiNbO is a linear or branched alkyl group₃The preparation method of the/PAN composite nanofiber electret anti-haze window screen is characterized by comprising the following steps of: the LiNbO₃the/PAN composite nano fiber is made of LiNbO₃The nano crystal and PAN nano fiber are compounded, wherein LiNbO is₃The mass ratio of the nanocrystals to the PAN nanofibers is (1-5): (1000-3000).

3. The LiNbO of claim 2, wherein the LiNbO is a linear or branched alkyl group₃The preparation method of the/PAN composite nanofiber electret anti-haze window screen is characterized by comprising the following steps of: the LiNbO₃The particle diameter of the nano crystal particles is 20-50 nm, LiNbO₃The diameter of the/PAN composite nanofiber fiber is 100-200 nm, and the porosity is 0.20-0.85 cm³/g。

4. The LiNbO of claim 1, wherein the LiNbO is a linear or branched alkyl group₃The preparation method of the/PAN composite nanofiber electret anti-haze window screen is characterized by comprising the following steps of: the preparation of LiNbO in the step (1)₃The nanocrystal comprises the following steps: a. weighing the Li₂CO₃And Nb₂O₅Preparation of Li by pouring into beaker₂CO₃And Nb₂O₅Mixed solution of (2), Li₂CO₃And Nb₂O₅The molar mass ratio of (1.0-5.0): (1.0-4.0), Li₂CO₃The molar concentration of (A) is 0.1-1.0 mol/L;

b. adding 0.1-0.5 mass percent of SDS (sodium dodecyl sulfate) into the mixed solution prepared in the step (a), stirring the mixed solution on a magnetic stirrer for 10-60 min, pouring the mixed solution into a reaction kettle, sealing the reaction kettle, and heating the reaction kettle to obtain a reaction product, wherein the heating temperature of the reaction kettle is 200-300 ℃, and the heating time is 12-24 h;

c. taking out the reaction product prepared in the step (b), and respectively washing the reaction product for 2-5 times by using distilled water and absolute ethyl alcohol; putting the cleaned product into a freeze drying oven at subzero temperatureDrying at 60-80 deg.C for 2-5 h to obtain LiNbO₃A nanocrystal.

5. The LiNbO of claim 1, wherein the LiNbO is a linear or branched alkyl group₃The preparation method of the/PAN composite nanofiber electret anti-haze window screen is characterized by comprising the following steps of: in step (2), LiNbO is ensured₃The nanometer crystal particles can be uniformly dispersed in DMF, and ultrasonic dispersion treatment is carried out on the nanometer crystal particles for 30-60 min by using an ultrasonic cleaner.

6. The LiNbO of claim 1, wherein the LiNbO is a linear or branched alkyl group₃The preparation method of the/PAN composite nanofiber electret anti-haze window screen is characterized by comprising the following steps of: the silver-plated polymer mesh structure in the step (4) is PP/chinlon/terylene, and the number of the holes of the silver-plated polymer mesh structure is 500-700 meshes.

7. The LiNbO of claim 1, wherein the LiNbO is a linear or branched alkyl group₃The preparation method of the/PAN composite nanofiber electret anti-haze window screen is characterized by comprising the following steps of: when the electrostatic spinning device in the step (4) works, the voltage of the high-voltage generator is 0-80 kV; the distance from the nozzle to the receiving base cloth is 10-15 cm; the caliber of the nozzle is 0.1-10 cm; the flow rate of the sprayed electrostatic spinning solution is 0.5-3.0 mL/h; the receiving time is 0.5-15 min.

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