CN112853606A

CN112853606A - Preparation method of high-elasticity stretchable white fluorescent nanofiber membrane responding to acid gas

Info

Publication number: CN112853606A
Application number: CN202011258074.7A
Authority: CN
Inventors: 潘凯; 赵世坤; 秦臻
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2020-11-11
Filing date: 2020-11-11
Publication date: 2021-05-28

Abstract

A preparation method of a high-elasticity stretchable white fluorescent nanofiber membrane responding to acid gas belongs to the technical field of fibers. According to the invention, by utilizing an electrostatic spinning technology, elastic polymer spinning solutions containing different fluorescent substances are respectively added into spinning needle channels with Janus structures, and the stretchable fluorescent nanofiber membrane with the Janus structures is prepared by controlling the temperature and the humidity. By utilizing a donor-acceptor fluorescence resonance energy transfer mechanism of white fluorescence emission and by means of space isolation of a Janus structure and large specific surface area of a porous structure of the nanofiber membrane, the nanofiber membrane capable of efficiently emitting white fluorescence is obtained. The Janus structure white fluorescent nanofiber membrane prepared by the invention has the characteristics of stretchability, crimpability and cuttability, and because the blue light molecules are easily protonated by pyrazine derivatives under acidic conditions, the color of light is changed. And generating a color response under an acid gas environment for gas detection of volatile acid.

Description

Preparation method of high-elasticity stretchable white fluorescent nanofiber membrane responding to acid gas

Technical Field

The invention relates to preparation of a high-elasticity stretchable Janus-structure porous nanofiber membrane responding to acid gas and regulation and control of corresponding fluorescence color, and belongs to the technical field of nanofibers.

Background

Luminescent materials are substances which are able to absorb energy in some way and convert it into light radiation. Fluorescence is a common photoluminescence phenomenon, when ultraviolet light or visible light with a shorter wavelength is irradiated to some substances, electrons in the substances absorb energy and transition from a ground state energy level to a high energy level, and because the electrons are in an unstable state when being in the high energy level, the electrons quickly transition from the high energy level to the low energy level, and release energy to emit visible light with various colors and different intensities. Only under the irradiation of exciting light can electron transition luminescence be realized. Such emission light generated by the excitation light is called fluorescence, and a substance capable of emitting fluorescence is called a fluorescent substance.

The fluorescent substance has two requirements, namely, the molecular structure of the substance contains a chemical structure capable of absorbing exciting light and converting the exciting light, such as conjugated double bonds; secondly, the molecule should have a high photoluminescence efficiency (the ratio of the number of emitted fluorescent photons to the number of absorbed excitation light photons after the fluorescent substance has absorbed light and activated). Groups capable of giving the molecule a fluorescent effect are called chromophores, and common are ═ C ═ O, -N ═ N-, -CH ═ N-, and-NH₂Groups such as-NHR, -OR, etc. can cause the absorption wavelength to change and the fluorescence to increase, and are called auxochromes.

In recent years, white fluorescent materials have great application potential in the field of backlight sources such as novel solid-state lighting, flat panel display, liquid crystal display and the like, and become a research hotspot, and particularly, the fluorescence of various colors applied in production and life can be indirectly obtained through a fluorescence conversion layer. At present, with the increasing demand of human beings on the living environment, inorganic fluorescent powder which has high energy consumption, large pollution and difficult regeneration is gradually replaced by novel high-efficiency white light materials. The construction of the white fluorescent conversion layer can avoid complicated packaging and dispensing processes, and is more suitable for the preparation of novel white light materials.

The white light source is mainly realized by two ways: i) multi-chip combination: a red, green and blue three-primary-color chip or a luminous tube is utilized to assemble a pixel to realize white light compositely. The white light obtained by the method has good adaptability and high color rendering index, but has the problems of technical requirements and production cost; ii) a light conversion material is mated to the single chip: blue light or near ultraviolet chips are used as excitation light sources to excite other luminescent materials to realize white light compounding. Whereas achieving white light emission by a single fluorescent molecule requires complex synthetic reactions. The method has the advantages of low preparation cost, simple packaging process, suitability for commercialization and becoming the most mature WLEDs technology at present. The fluorescence conversion layer is composed of a donor-acceptor energy transfer composite system, and has become a main way for realizing white light regulation due to higher luminous efficiency. Generally, in a donor-acceptor system, a molecule at a high energy level absorbs energy of excitation light provided from the outside to complete self fluorescence emission, meanwhile, the donor fluorescent molecule transfers part of the absorbed energy to an acceptor fluorescent molecule at a low energy level through Forst energy transfer, and the acceptor molecule absorbs the energy and excites fluorescence emission or enhancement. And finally, an energy continuous transfer system is constructed through the accurate regulation and control of red, green and blue three primary color fluorescent molecules or one three primary color and the complementary color thereof, and the emission of white light or other light colors is obtained through the mixing of the superposition effect.

The realization of white light emission of an energy transfer system needs to ensure that certain space isolation exists between fluorescent materials, and when the distance between two different fluorescent molecules is larger than the Forst energy transfer radius, fluorescence quenching caused by energy transfer between the fluorescent materials can be avoided. The emission peak of each light color appears obviously, and white fluorescence can be obtained when the emission peaks are matched according to a certain intensity proportion. Therefore, for preparing the white light emitting material, the content of the fluorescent substance needs to be reasonably adjusted, and certain space isolation needs to be performed on fluorescent molecules.

The electrostatic spinning technology is used as an efficient nano material preparation means, has simple process and low price, is suitable for preparing various high-performance organic or inorganic materials, and the obtained nano fibers have uniform size and good application prospect in the fields of filtration, sensing, energy, catalysis, biomedicine and the like. Particularly, the nanofiber has unique application advantages in the aspect of photoelectric material devices, and the fluorescent nanofiber membrane which is high in porosity, high in specific surface area, light in weight, thin in thickness, flexible, bendable and capable of being cut at will can be easily obtained by doping fluorescent dye, conjugated polymer, rare earth compound or quantum dot and the like into the nanofiber. As a fluorescent material without a binder, the fluorescent material does not have the basic problems of aging, dispersion and the like which troubles the development of the traditional fluorescent material. The fluorescence conversion material is prepared by utilizing electrostatic spinning, and can be customized according to the physicochemical properties of the fluorescence material, so that the fluorescence nanofiber membrane with rich varieties, various structures and stable performance can be obtained.

Generally, the electrospun nanofiber obtained by single-needle electrostatic spinning can only blend multiple dopants in the same polymer matrix, and is difficult to realize spatial separation of multiple fluorescent molecules, so that the phenomenon of quenching due to excessive energy transfer is easily caused, the difficulty is brought to light color regulation, and an ideal fluorescent nanofiber membrane cannot be prepared.

Janus material refers to two-phase heterogeneous microstructure materials with different zonal compositions or property differences. Due to the special structural characteristics and multifunctional characteristics, the composite material has great application potential in the fields of photoelectric devices, electrocatalysis, oil-water separation, drug carriers and the like in recent years. Janus nanofibers can be simply prepared by utilizing two injector needles which are respectively filled with spinning solutions with different components to be contacted with each other and to be spun side by side. The spinning solution is gradually solidified in the air to form two-component heterogeneous nano fibers which are arranged side by side, and meanwhile, multifunctional compounding is realized.

The thermoplastic elastomer is a thermoplastic material with good transparency, abrasion resistance, corrosion resistance and high elasticity, and has important application prospects in the fields of automobiles, biology, clothing, electronics and the like. As the matrix polymer for electrospinning, a functional stretchable flexible nanofiber membrane can be simply prepared by doping. The tetraphenylpyrazine derivative is a small molecule with aggregation-induced emission effect, and has weak or even no luminescence in a low-concentration solution state, and has stronger fluorescence emission in an aggregation state or a high concentration. Pyrazine molecules are easily protonated under acidic conditions to cause a change in luminescent color.

Stretchable white light nanofibers, as a class of flexible luminescent materials with nanoscale, are drawing attention due to their low preparation cost, easy processing, flexible usage, and incomparable advantages of other traditional white light materials. The flexible matrix makes it suitable for various scenes, and the high elasticity makes it suitable for wide application field. With the development of the 5G communication technology, artificial intelligence will make great progress, and the stretchable white light material is inevitably applied to various fields such as photoelectric devices, flexible displays and sensors, and promotes the rapid development of emerging industries such as flexible equipment, intelligent fabrics and health management.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a method for preparing an acid gas response high-elasticity stretchable white light nanofiber membrane. The technical scheme is as follows:

in order to achieve the aim, the invention provides a preparation method of a high-elasticity stretchable white light nanofiber membrane, which comprises the steps of enabling two needle heads to be closely arranged side by side, and enabling the two needle heads to be fixed through sleeving a hard tube on the two needle heads, wherein the hard tube is slightly longer than the tail ends of the needle heads by 1-2 mm. Converging the spinning solution at the tail end of the hard tube, forming a Taylor cone in an electrostatic field, and controlling the temperature, the humidity and the receiving distance of a spinning environment by adjusting spinning parameters to evaporate and quickly solidify a spinning solution solvent so as to stably and continuously obtain the Janus nano fibers with the heterostructure along the axial direction of the fibers; by utilizing a side-by-side electrostatic spinning method, polymer spinning solutions of different fluorescent substances are respectively added into two injectors, electrostatic spinning parameters are adjusted, and the temperature and the humidity of a spinning environment are controlled, so that the fluorescent nanofiber membrane which is uniform in diameter, has a certain arrangement orientation, can be controlled in a patterning mode, and is high in elasticity can be prepared.

The invention simply designs and assembles the electrostatic spinning equipment, and takes one or two different polymers as matrixes to be respectively doped with different fluorescent substances as spinning solutions; through adjusting spinning parameters, the temperature, the humidity and the receiving distance of a spinning environment are controlled, the Janus nanofibers of the heterostructure along the axial length direction of the fibers are stably and continuously obtained, the space isolation effect brought by the Janus structure is utilized, different fluorescent molecules are located on two sides of the surface parallel to the axial surface of the fibers, the fluorescence energy transfer is controlled, the large specific surface area brought by the porous structure of the nanofiber membrane is combined, the effective light emitting surface of the fibers is improved, and finally the regulation and control of the fluorescence color of the nanofibers and the efficient emission of white fluorescence are achieved.

Specifically, the nanofiber matrix polymer comprises polymers which can be used for electrostatic spinning, such as Polyurethane (PU), styrene-butadiene-styrene block copolymer (SBS) nylon elastomer and the like, and the used organic solvent is a good solvent corresponding to the polymers (such as N, N-Dimethylformamide (DMF), Tetrahydrofuran (THF), Dichloromethane (DCM) and formic acid).

Specifically, the fluorescent substance is a blue or orange fluorescent substance with high fluorescence intensity and high fluorescence color purity, and mainly comprises a blue fluorescent substance such as anthracene derivatives, acridine derivatives, tetraphenylpyrazine derivatives and the like, and an orange fluorescent substance such as rhodamine, perylene imide, tetraphenylethylene derivatives and the like.

Specifically, the polymer is preferably selected from thermoplastic polyurethane elastomer (TPU) and styrene-butadiene-styrene block copolymer (SBS).

Specifically, the fluorescent substance is preferably a blue fluorescent substance tetraphenylpyrazine derivative, and the orange fluorescent substance is preferably a tetraphenylethylene derivative.

Specifically, the solvent used in the polymer solution is preferably selected from N, N-Dimethylformamide (DMF), Tetrahydrofuran (THF), and Dichloromethane (DCM).

Specifically, the mass fractions of the polymers in the spinning solution are preferably 15 to 21 wt% TPU and 10 to 18 wt% SBS, respectively.

Specifically, the mass ratio of the fluorescent substance to the polymer used for spinning is preferably: orange light molecule 1:80-150, blue light molecule 0.3: 80-150.

The preparation method for preparing the flexible white light fluorescent nanofiber membrane comprises the following operation steps:

preparation of polymer solution for spinning: respectively dissolving one or two polymers in an organic solvent according to an optimal ratio, and magnetically stirring for 6 hours at room temperature to completely dissolve the polymers to obtain a transparent and uniform spinning solution;

preparation of fluorescent spinning solutions: weighing a certain amount of fluorescent substances according to the adding proportion, respectively adding the fluorescent substances into the two polymer solutions, and magnetically stirring the fluorescent substances at room temperature until the fluorescent substances are completely dissolved to obtain two parts of spinning solutions containing the fluorescent substances;

janus structure nanofiber spinning equipment is built: the self-made coaxial syringe needle side-by-side injector mainly comprises a self-made coaxial syringe needle side-by-side injector needle, a connector, a combined frame, a propelling pump, a receiving plate, a high-voltage power supply, an injector and the like;

preparing a flexible white fluorescent nanofiber membrane: the content of the fluorescent substance is reasonably adjusted, and by utilizing the parallel electrostatic spinning method, electrostatic spinning parameters including voltage, the propelling speed and the receiving distance of the two injectors are adjusted, and the temperature and the humidity of the electrostatic spinning environment are controlled, so that the stretchable white fluorescent porous nanofiber membrane can be obtained. The specific spinning environment temperature, humidity and receiving distance can be adjusted according to needs, and finally the obtained silk solution solvent is evaporated and rapidly solidified to form the Janus nano-fiber with the heterostructure along the axial length direction of the fiber. Spinning voltage is 9-15kV, the distance from a spinning nozzle to a receiving plate is 10-20cm, the temperature is 30-45 ℃, the humidity is 35 +/-5%, and the propelling speed of two sides is 0.004-0.006 mL/min.

The method specifically comprises the following detailed operation steps:

(1) preparation of the polymer solution: respectively dissolving one or two polymers in an organic solvent, and magnetically stirring for 6 hours at room temperature to completely dissolve the polymers to obtain a polymer solution;

(2) preparation of fluorescent spinning solutions: calculating and weighing a certain amount of fluorescent substances, respectively adding the fluorescent substances into the polymer solution, and magnetically stirring until the fluorescent substances are completely dissolved to obtain a spinning solution containing the fluorescent substances;

(3) assembling side-by-side electrostatic spinning equipment;

(4) preparing a high-elasticity flexible white fluorescent nanofiber membrane: the content of the fluorescent substance is reasonably adjusted, and by utilizing the parallel electrostatic spinning method, the electrostatic spinning parameters are adjusted, and the temperature and the humidity of the electrostatic spinning environment are controlled, so that the stretchable white fluorescent nanofiber membrane can be obtained.

The two-dimensional fluorescent material finally prepared by the invention has all characteristics of an electrostatic spinning nanofiber membrane, such as nano-size effect, high porosity, ultra-large specific surface area, light weight, flexibility, bending and folding, certain distribution range of fiber diameter and pore diameter and the like, can be stretched under external tension, and can be restored after external force is removed within a certain external force range. Under the excitation of ultraviolet light, the nanofiber membrane can emit uniform white fluorescence, and the light-emitting effect is stable; when the white light nanofiber membrane is placed under hydrochloric acid steam (placed at the cup mouth of a 0.5mol/L hydrochloric acid aqueous solution beaker), the observation can be carried out within 1s, under 365nm ultraviolet light, the white fluorescent nanofiber membrane turns into yellow green fluorescence, and is placed in the air within 5s, the white fluorescent nanofiber membrane can recover white, the reversibility is good, and the white fluorescent nanofiber membrane can be repeatedly used. Has great potential for detection and identification of acidic environments.

Drawings

In order to more clearly illustrate the technical solution in the embodiment, the drawings needed to be used in the description of the embodiment are briefly introduced below, the drawings in the description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a side-by-side electrospinning method according to an embodiment of the present invention for preparing a stretchable white fluorescent nanofiber membrane with a Janus structure;

FIG. 2 is a schematic diagram of a luminescence mechanism of a Janus structure fluorescent nanofiber prepared by a side-by-side electrospinning method according to an embodiment of the present invention;

FIG. 3 is a scanning, transmission electron microscope and nanofiber diameter distribution diagram of a coaxial porous nanofiber membrane prepared by a coaxial electrospinning method according to an embodiment of the present invention;

FIG. 4 is a fluorescence spectrum and corresponding CIE chromaticity diagram of the stretchable white fluorescent nanofiber membrane under 365nm excitation light, and a stress-strain curve of the fluorescent nanofiber membrane provided in the embodiment of the invention;

FIG. 5 is a pictorial representation of a stretchable white light nanofiber membrane obtained in an example of the present invention;

fig. 6 is a representation of the response of the white light fiber membrane to acid gas obtained in the embodiment of the invention, fig. a and b are a PL spectrum and a CIE chromaticity diagram of the white light nanofiber membrane before encountering acid, and fig. c and d are a PL spectrum and a CIE chromaticity diagram under an acid atmosphere.

Detailed Description

In order to make the purpose and technical solution of the present invention clearer, the present invention is further described below with reference to specific examples.

By using a side-by-side electrostatic spinning method, polymer spinning solutions containing two different fluorescent substances are respectively added into two injectors, wherein one fluorescent molecule is sensitive to acid, changes color under an acidic condition, and can be quickly recovered after being separated from an acidic environment. The fluorescent nanofiber membrane with uniform diameter, certain arrangement orientation, patternable control and high elasticity can be prepared by adjusting electrostatic spinning parameters and controlling the temperature and the humidity of a spinning environment, the ratio of two fluorescent substances is further reasonably adjusted, and finally the stretchable white fluorescent nanofiber membrane responding to the acid gas can be obtained.

The self-made Janus needle is used as a spinning nozzle, the assembled electrostatic spinning equipment is used for adding different fluorescent substances into one or two polymers respectively to serve as spinning solutions, spinning parameters are adjusted, the temperature and the humidity of a spinning environment are controlled, each nanofiber with a Janus porous structure is stably and continuously obtained, the fluorescence energy transfer is controlled by utilizing the space isolation effect brought by the Janus structure, the effective light emitting surface of the fiber is improved by the large specific surface area brought by the porous structure, and finally the regulation of the fluorescence color of the nanofiber and the efficient emission of white fluorescence are achieved.

Example 1

The embodiment of the invention provides a method for preparing a stretchable white fluorescent fiber membrane by self-made parallel electrostatic spinning equipment, which comprises the following specific operation steps: dissolving 18% wt of TPU in 4ml of THF/DMF mixed solvent (v/v ═ 1:1), and stirring by magnetic force for 6h to completely dissolve the polymer; then adding 1 wt% of blue fluorescent substance tetraphenylpyrazine derivative and 0.3 wt% of orange fluorescent substance tetraphenylethylene derivative into two identical TPU solutions respectively, and then stirring until the fluorescent substances are completely dissolved to obtain two spinning solutions containing the fluorescent substances.

And respectively adding the two fluorescent spinning solutions into a self-made parallel spinning propelling injector, placing a blue fluorescent spinning solution on the left side, placing an orange fluorescent spinning solution on the right side, converging at a needle connector to form a Taylor cone, controlling the voltage (12KV) and the propelling speed (the propelling speed on the left side: 0.006mL/min and the propelling speed on the right side: 0.004mL/min), receiving the electrospinning parameters such as 15cm and the like, and spinning environment (the humidity: 35 +/-5% and the temperature: 40 ℃) to perform continuous and stable electrospinning for a period of time by using a parallel electrostatic spinning method to obtain the fluorescent nanofiber membrane with the Janus structure (the diameter of a fiber is 400-600 nm).

The obtained nanofiber membrane can obtain uniform and bright white light emission under the action of 365nm exciting light. The nanofiber membrane can rapidly respond to a yellow-green color change under 0.5mol/L hydrochloric acid vapor.

Example 2

The embodiment of the invention provides a method for preparing a white light fluorescent flexible porous nanofiber membrane by self-made coaxial electrostatic spinning equipment, which comprises the following specific operation steps: dissolving 18% wt of TPU and 12% wt of SBS in 4ml of THF/DMF mixed solvent (v/v ═ 1:1) and 4ml of DCM/DMF mixed solvent (v/v ═ 2:5), respectively, and magnetically stirring at room temperature for 4h to completely dissolve the polymer; then weighing a certain amount of fluorescent substances and adding the fluorescent substances into respective polymer solutions, wherein 1 wt% of blue fluorescent substance tetraphenylpyrazine derivative is added into the TPU solution, and 0.3 wt% of orange fluorescent substance tetraphenylethylene derivative is added into the PAN solution, and then stirring the mixture until the fluorescent substances are completely dissolved to obtain two kinds of spinning solutions containing the fluorescent substances.

And respectively adding the two fluorescent spinning solutions into a self-made parallel electrostatic spinning injector, placing the blue fluorescent spinning solution on the left side, placing the orange fluorescent spinning solution on the right side, and mixing the two fluorescent spinning solutions at the joint of the needles. Spinning parameters such as spinning voltage (11KV) and advancing speed (advancing rate on the left side: 0.006mL/min, advancing rate on the right side: 0.004mL/min) were adjusted, the reception distance 15cm, and the temperature of the spinning environment was 40 ℃, humidity: 35 +/-5%), continuously and stably electrospinning for a period of time by using a side-by-side electrospinning method to obtain the fluorescent nanofiber membrane with the Janus structure.

The nanofiber membrane obtained in the above way can be used for obtaining a stretchable white fluorescent nanofiber membrane under the action of 365nm exciting light. The nanofiber membrane can rapidly respond to a yellow-green color change under 0.5mol/L hydrochloric acid vapor.

Example 3

The embodiment of the invention provides a method for patterning a stretchable white light nanofiber membrane by self-made side-by-side electrostatic spinning equipment, which comprises the following specific operation steps: respectively dissolving 18 wt% of TPU and 12 wt% of SBS in proper amounts of THF and DMF mixed solvent (v/v ═ 1:1 and DCM/DMF mixed solvent (v/v ═ 2:5), and magnetically stirring at room temperature for 4h to completely dissolve the polymer; and then respectively weighing a certain amount of fluorescent substances and adding the fluorescent substances into respective polymer solutions, wherein 1 wt% of blue fluorescent substance tetraphenylpyrazine derivative is added into the TPU solution, and 0.3 wt% of orange fluorescent substance tetraphenylethylene derivative is added into the SBS solution, and then stirring is carried out until the fluorescent substances are completely dissolved, so as to obtain two spinning solutions containing the fluorescent substances.

And respectively adding the two obtained fluorescent spinning solutions into a self-made parallel spinning pushing injector, placing a blue fluorescent spinning solution on the left side, using an orange fluorescent spinning solution as a right spinning solution, using a roller covered with tinfoil paper as a receiver, setting the receiving distance to be 15cm, or using a program to control the two pushing injectors to move left and right, changing the pushing speeds of two channels to change constantly, using a parallel electrostatic spinning method, controlling the spinning environment (the humidity is 35 +/-5%, the temperature is 40 ℃) and performing electrospinning for a period of time to obtain the patterned fluorescent porous nanofiber membrane.

The obtained Janus structure fluorescent nanofiber membrane can be used for obtaining a high-elasticity stretchable fluorescent nanofiber membrane with various colors including white light under the action of 365nm exciting light, and the maximum breaking elongation can reach 550%.

In summary, the embodiments of the present invention provide a method for preparing a high-elasticity stretchable white fluorescent nanofiber membrane with a Janus structure by using a self-made parallel electrospinning device, and the prepared membrane has good elasticity and can be bent, curled, stretched and retracted at room temperature. The Janus structure effectively isolates two different fluorescent molecules, fluorescence quenching caused by excessive energy transfer is prevented, and meanwhile, the selected fluorescent molecules have an aggregation-induced luminescence effect, so that high-concentration high-brightness high-efficiency fluorescence emission can be realized. Meanwhile, the fiber has a porous structure, is light and breathable, is simple to operate, has good controllability, and is suitable for photoelectric intelligent materials and color development materials, particularly for multi-dimensional activities of high-elasticity organisms, and electronic skin and intelligent wearable equipment are constructed.

The examples are given solely for the purpose of illustration and are not intended to limit the scope of the invention. In addition, after reading the content of the authorization of the present invention, any modification, equivalent replacement, improvement, etc. made by those skilled in the art shall be included in the protection scope of the present invention.

Claims

1. A preparation method of an acid gas response high-elasticity stretchable white fluorescent nanofiber membrane is characterized in that two needle heads are closely arranged side by side, the two needle heads are fixed by sleeving a hard tube on the two needle heads, the hard tube is slightly longer than the tail ends of the needle heads by 1-2mm, and spinning solutions are converged at the tail ends of the hard tube and form a Taylor cone under an electrostatic field. By using a side-by-side electrostatic spinning method, the temperature, the humidity and the receiving distance of a spinning environment are controlled by adjusting spinning parameters, so that a spinning solution solvent is evaporated and rapidly solidified, and the Janus nanofibers with the heterostructure along the axial length direction of the fibers are stably and continuously obtained; by utilizing a side-by-side electrostatic spinning method, polymer spinning solutions of different fluorescent substances are respectively added into two injectors, electrostatic spinning parameters are adjusted, and the temperature and the humidity of a spinning environment are controlled, so that the fluorescent nanofiber membrane which is uniform in diameter, has a certain arrangement orientation, can be controlled in a patterning mode, and is high in elasticity can be prepared.

2. The preparation method of the acid gas responsive high-elasticity stretchable white fluorescent nanofiber membrane according to claim 1, characterized in that nanofibers each having a Janus structure are stably and continuously obtained, fluorescence energy transfer is controlled by utilizing a spatial isolation effect brought by the Janus structure, a large specific surface area of a nanofiber membrane porous structure is formed, an effective light emitting surface of the fiber is improved, and finally regulation of the fluorescence color of the nanofibers and efficient emission of white fluorescence are realized.

3. The method of claim 1, wherein the polymer is selected from Thermoplastic Polyurethane (TPU), styrene-butadiene-styrene block polymer (SBS), etc. elastic polymers useful for electrostatic spinning, and the organic solvent is a good solvent corresponding to the polymer, preferably Tetrahydrofuran (THF), N' N-Dimethylformamide (DMF), Dichloromethane (DCM), etc.

4. The method of claim 1 wherein the fluorescent material is a blue or orange fluorescent material with high fluorescent intensity and high fluorescent color purity, one syringe is a blue fluorescent material and the other syringe is an orange fluorescent material.

5. The method of claim 4 wherein the blue phosphor is selected from tetraphenylpyrazine derivatives, anthracene derivatives, acridine derivatives, polyfluorenes, etc., and the orange phosphor is selected from tetraphenylethylene derivatives, rhodamine 6G, perylene imides, etc.

6. The method of claim 1, wherein the side-by-side electrospinning process is controlled by using different receivers such as rollers, or by using programmed control of the movement of the spinneret orifice or the receiving plate, to obtain a highly elastic nanofiber membrane with oriented fibers or even patterned design.

7. The method for preparing the acid gas responsive high-elasticity stretchable white fluorescent nanofiber membrane as claimed in claim 1, which is characterized by comprising the following detailed operation steps:

(1) preparation of the polymer solution: respectively dissolving one or two polymers in an organic solvent, and magnetically stirring at room temperature until the polymers are completely dissolved to obtain a polymer solution;

(2) preparation of fluorescent spinning solutions: weighing a certain amount of fluorescent substances, respectively adding the fluorescent substances into the polymer solution, and magnetically stirring until the fluorescent substances are completely dissolved to obtain a spinning solution containing the fluorescent substances;

(3) assembling side-by-side electrostatic spinning equipment;

8. The method of making an acid gas responsive, highly elastic stretchable white fluorescent nanofiber membrane of claim 1, wherein the side-by-side electrospinning operating parameters are: spinning voltage is 9-15kV, distance from spinning nozzle to receiving plate is 10-20cm, temperature is 30-45 deg.C, humidity is 35 + -5%, and advancing speed at both sides is 0.004-0.006 mL/min.

9. An acid gas responsive highly elastic stretchable white fluorescent nanofiber membrane prepared according to the method of any one of claims 1 to 8.

10. The application of the acid gas response high elasticity stretchable white fluorescent nanofiber membrane prepared according to any one of claims 1-8, wherein the nanofiber membrane can emit uniform white fluorescence under the excitation of ultraviolet light, and the luminous effect is stable; when the white-light nanofiber membrane is placed in hydrochloric acid steam, the white-light nanofiber membrane can be observed within 1s, under 365nm ultraviolet light, the white-light-emitting nanofiber membrane turns yellow-green fluorescence and is placed in air within 5s, and then the white-light-emitting nanofiber membrane returns to white, so that the reversibility is good, the white-light-emitting nanofiber membrane can be recycled, and the white-light-emitting nanofiber membrane is used for detection and identification of an acidic environment.