CN115723457A - Reversible humidity response fluorescent color-changing system, preparation method and application thereof - Google Patents
Reversible humidity response fluorescent color-changing system, preparation method and application thereof Download PDFInfo
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Abstract
The invention provides a preparation method of a reversible humidity response fluorescent color-changing system, which comprises the following steps: a) Mixing anionic polyelectrolyte, fluorescent molecules and water to obtain an electrostatic spinning aqueous solution; b) Carrying out electrostatic spinning on the electrostatic spinning aqueous solution, and arranging a mask at a receiving end to draw a first heavy fluorescent pattern to obtain an electrostatic spinning film with the first heavy fluorescent pattern; c) And B) drawing a second anti-counterfeiting pattern on the surface of the electrostatic spinning film obtained in the step B) by using the waterproof coating to obtain a reversible humidity response fluorescent color-changing system. The application also provides a reversible humidity-responsive fluorescent color-changing system and application thereof. The reversible humidity-response fluorescence color-changing system provided by the invention has a fluorescence double anti-counterfeiting function, and can present a first pattern under ultraviolet light and a second pattern when the humidity rises (such as haar), so that the anti-counterfeiting performance of the fluorescence pattern is greatly improved; and it has specificity to water and fluorescent color change reversible rapid humidity response color change.
Description
Technical Field
The invention relates to the technical field of anti-counterfeiting, in particular to a reversible humidity response fluorescent color-changing system, a preparation method and application thereof.
Background
The humidity measurement is closely related to the life of human beings, and through a plurality of technical iterations, the semiconductor humidity sensor is distinguished by the advantages of accurate measurement and convenient integration, but the semiconductor humidity sensor has the problems of complex and heavy manufacture and no electromagnetic interference resistance. With the demand of people for intelligent devices, people have created a need for humidity sensors that provide visualization of perceptual awareness.
The existing humidity-color response materials comprise water-made color-changing dyes, inorganic nanocrystals and structural color materials, but the water-made color-changing dyes have long synthesis flow, the inorganic nanocrystals have poor chemical stability, and the photonic crystal materials are complex to prepare. The organic fluorescence is bright and stable in color, and can be greatly improved if the organic fluorescence is used for a material with humidity-color response.
In addition, along with the development of economy and society, counterfeit and shoddy products become too defensive along with the reduction of technical thresholds, so the anti-counterfeiting technology is very important and needs to be continuously updated in an iterative manner. Current fluorescent anti-counterfeiting methods mostly rely on one or several emission wavelengths of specific colors for presenting the encrypted pattern. Most of the existing fluorescent pattern anti-counterfeiting technologies are designed for anti-counterfeiting patterns by using certain fluorescent substances to emit fluorescent light with specific colors through ultraviolet light excitation, and few fluorescent units with stimulus response are used for realizing appearance/disappearance or change of the fluorescent patterns, so that the anti-counterfeiting patterns are single and easy to imitate.
Disclosure of Invention
The invention aims to solve the technical problem of providing a reversible humidity-response fluorescent color-changing system and a preparation method thereof.
The application provides a preparation method of a reversible humidity response fluorescent color-changing system, which comprises the following steps:
a) Mixing anionic polyelectrolyte, fluorescent molecules and water to obtain an electrostatic spinning aqueous solution; the fluorescent molecules are fluorescent molecules with color changed after receiving protons;
b) Carrying out electrostatic spinning on the electrostatic spinning aqueous solution, and arranging a mask at a receiving end to draw a first heavy fluorescent pattern to obtain an electrostatic spinning film with the first heavy fluorescent pattern;
c) And B), drawing a second anti-counterfeiting pattern on the surface of the electrostatic spinning film obtained in the step B) by using the waterproof coating to obtain a reversible humidity-responsive fluorescent color-changing system.
Preferably, the anionic polyelectrolyte is polyacrylic acid, polymethacrylic acid or poly (2-acrylamido-2-methylpropanesulfonic acid); the fluorescent molecule is a compound with a conjugated skeleton directly connected with an amino group, an imino group and a pyridyl group, specifically, the fluorescent molecule is selected from tetra (4-pyridine biphenyl) ethylene, tetra (4-pyridine vinyl phenyl) ethylene or (2Z, 2 'Z) -2,2' - ((1, 4-phenylene) bis (3- (4-pyridyl phenyl) acrylonitrile), the waterproof coating comprises a waterproof material and a solvent, the waterproof material is selected from one or more of paraffin, polymethacrylic acid, polyethylene wax, polystyrene, polyvinyl fluoride and vaseline, and the mass ratio of the anionic polyelectrolyte to the fluorescent molecule is (500-1000): 1.
Preferably, the step of electrospinning specifically comprises:
sucking the electrostatic spinning aqueous solution into an injector, transferring the injector to an injection device for electrostatic spinning, and adjusting injection parameters; coating an aluminum foil on the receiving roller, connecting the receiving end with the negative pole of a power supply, and connecting the needle of the injector with the positive pole of the power supply; arranging a mask on a receiving end, starting a receiving end rolling device and an emitting end translation mode, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the voltage of the emitting end to reach a required voltage to obtain the electrostatic spinning film with the first heavy fluorescent pattern.
Preferably, the electrospinningThe filament voltage is 10-20 kV, the receiving end voltage is-1.5 kV to-2.5 kV, the receiving end distance is 15-20 cm, and the spinning speed is 8-15 μm.min -1 (ii) a The concentration of the electrostatic spinning aqueous solution is 5-15 wt%.
Preferably, the diameter of the spun fiber in the electrospun film is 200 to 300nm.
Preferably, step C) is specifically:
mixing a waterproof material with an organic solvent to obtain a waterproof coating; the waterproof material is selected from one or more of paraffin, polymethacrylic acid, polyethylene wax, polystyrene, polyvinyl fluoride and vaseline;
and transferring the target pattern onto the surface of the electrostatic spinning film by using a mask method or a stamping method and using waterproof paint, and drying the electrostatic spinning film after the pattern is transferred to obtain the reversible color-changing fluorescent double anti-counterfeiting pattern.
Preferably, the electrospinning aqueous solution further comprises an auxiliary polymer, wherein the auxiliary polymer is selected from one or more of polyvinylpyrrolidone, polyvinyl alcohol and polyethylene glycol.
The application also provides a reversible humidity response fluorescence discoloration system, which consists of an electrostatic spinning film with a first heavy fluorescent pattern and a second heavy anti-counterfeiting pattern compounded on the surface of the first heavy fluorescent pattern, wherein the electrostatic spinning film comprises anionic polyelectrolyte and fluorescent molecules, the fluorescent molecules are fluorescent molecules with color changed after receiving protons, and the second heavy anti-counterfeiting pattern is obtained by drawing waterproof paint.
Preferably, the electrospun film further comprises an auxiliary polymer, wherein the auxiliary polymer is one or more selected from polyvinylpyrrolidone, polyvinyl alcohol and polyethylene glycol.
The application also applies to the reversible humidity-responsive fluorescent color-changing system prepared by the preparation method or the application of the reversible humidity-responsive fluorescent color-changing system in the anti-counterfeiting field.
The application provides a reversible humidity-responsive fluorescence color-changing system which comprises a base material, an electrostatic spinning film which is compounded on the surface of the base material and is provided with a first heavy fluorescent pattern, and a waterproof layer which is compounded on the surface of the first heavy fluorescent pattern and is provided with an anti-counterfeiting pattern, wherein the electrostatic spinning film comprises an anionic polyelectrolyte and fluorescent molecules, and the fluorescent molecules are fluorescent molecules with color changing after receiving protons. The reversible humidity-responsive fluorescence discoloration system provided by the application constructs a stimulus-responsive system by means of fluorescent molecules and a polymer substrate, no pattern exists under visible light, the system presents a first heavy fluorescent pattern under an ultraviolet lamp due to the existence of the fluorescent molecules, and under the condition of humidity change, anion polyelectrolyte is ionized to generate protons, and the fluorescent molecules undergo proton discoloration, so that the second heavy fluorescent pattern is displayed under the condition of humidity change. Furthermore, the reversible humidity response fluorescence color-changing system provided by the application is prepared through electrostatic spinning, rapid humidity response can be realized, meanwhile, the fluorescence color-changing system has specific response to water, and the organic solvent interference resistance is strong.
Drawings
FIG. 1 is a scanning electron micrograph (FIG. 1 a) and fiber distribution (FIG. 1 b) of an electrospun fiber film prepared in example 1;
FIG. 2 is a comparison graph of the IR spectra of electrospun fiber films prepared in example 1 in dry and humid environments;
FIG. 3 shows the change of fluorescence color and fluorescence intensity of the electrospun fiber membrane prepared in example 1 in different humidity environments;
FIG. 4 is a graph of the fluorescence spectra of electrospun fiber films prepared in example 1 cycled in a dry-wet environment;
FIG. 5 is a graph of the fluorescence spectra of electrospun fiber films prepared in example 1 in different solvent fumigations;
FIG. 6 is a graph showing the current change under constant voltage conditions of the electrospun fiber film prepared in example 1;
fig. 7 is a fluorescence photograph of the first heavy fluorescent pattern drawn by the electrostatic spinning prepared in example 1 and the second heavy fluorescent pattern obtained after the transfer printing of the anti-counterfeiting pattern under visible light and ultraviolet light.
Detailed Description
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.
Aiming at the problems of humidity and anti-counterfeiting, the application provides a reversible humidity response fluorescence color-changing system, which can generate fluorescence red shift along with the rise of humidity to realize the visual sensing of the humidity, has the fluorescence double anti-counterfeiting function, presents a first heavy pattern under ultraviolet light, presents a second heavy pattern when the humidity rises (such as haar), and greatly improves the anti-counterfeiting performance of the fluorescence pattern; and has specificity to water and rapid humidity response color change which is reversible with fluorescence color change. Specifically, the application firstly provides a preparation method of a reversible humidity response fluorescence color-changing system, the method mixes anionic polyelectrolyte and fluorescent molecules to obtain an electrostatic spinning aqueous solution, and then utilizes an electrostatic spinning technology to prepare a first heavy fluorescent pattern; and the waterproof layer is transferred on the fluorescent patterns by using a mask method or a stamping method to realize the drawing of the second layer of anti-counterfeiting patterns, so that the anti-counterfeiting performance of the fluorescent anti-counterfeiting fiber is further improved, and the reversible conversion of fluorescence-humidity color change is realized. Specifically, the embodiment of the invention discloses a preparation method of a reversible humidity response fluorescence color-changing system, which comprises the following steps:
a) Mixing anionic polyelectrolyte, fluorescent molecules and water to obtain an electrostatic spinning aqueous solution; the fluorescent molecules are fluorescent molecules with color changed after receiving protons;
b) Carrying out electrostatic spinning on the electrostatic spinning aqueous solution, and arranging a mask at a receiving end to draw a first heavy fluorescent pattern to obtain an electrostatic spinning film with the first heavy fluorescent pattern;
c) And B) drawing a second anti-counterfeiting pattern on the surface of the electrostatic spinning film obtained in the step B) by using the waterproof coating to obtain a reversible humidity response fluorescent color-changing system.
In the process of preparing the reversible humidity response fluorescence discoloration system, the anionic polyelectrolyte, the fluorescent molecules and water are mixed to obtain the electrostatic spinning aqueous solution. In the present application, the anionic polyelectrolyte is a commercially available product or a product prepared by a method well known to those skilled in the art, including but not limited to one or more of acrylic acid, methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, copolymerized or mono-polymerized and then blended, and purified by dialysis to have a relatively narrow molecular weight distribution, which is advantageous for the subsequent relevant spinning step; specifically, the anionic polyelectrolyte is selected from polyacrylic acid, polymethacrylic acid or poly (2-acrylamido-2-methylpropanesulfonic acid). The fluorescent molecule is a fluorescent molecule that undergoes a color change upon acceptance of protons, i.e., a compound having an amino group, an imino group, a pyridyl group, a pyrrolyl group, a thiazolyl group, an imidazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrrolyl group, a quinolyl group, etc., directly attached to a conjugated backbone thereof, can undergo proton transfer or a ring opening/cyclization reaction catalyzed by protons, and thus cause a change in LUMO/HOMO level to change a fluorescent color, and more particularly, is selected from tetrakis (4-pyridylbiphenyl) ethylene, tetrakis (4-pyridylvinylphenyl) ethylene, or (2Z, 2 'Z) -2,2' - ((1, 4-phenylene) bis (3- (4-pyridylphenyl) acrylonitrile), is a commercially available product or is prepared according to methods well known to those skilled in the art.
In the electrostatic spinning aqueous solution, the mass ratio of the anionic polyelectrolyte to the fluorescent molecules is (500-1000): 1, specifically, the mass ratio of the anionic polyelectrolyte to the fluorescent molecule is (700-900): 1; the concentration of the electrospinning aqueous solution is 5 to 15wt%, and more specifically, the concentration of the electrospinning aqueous solution is 7 to 10wt%. In the application, the electrostatic spinning aqueous solution also comprises an auxiliary polymer which has good water solubility and better fiber forming and supporting performances so as to assist the electrostatic spinning of anionic polyelectrolyte, which is not easy to realize, in preparing an electrostatic spinning film; specifically, the auxiliary polymer is selected from one or more of polyvinylpyrrolidone, polyvinyl alcohol and polyethylene glycol.
According to the method, the electrostatic spinning aqueous solution is subjected to electrostatic spinning, and in the process, a mask is arranged at a receiving end to draw a first fluorescent pattern, so that an electrostatic spinning film with a first heavy fluorescent pattern is obtained; the electrostatic spinning process specifically comprises the following steps:
sucking the electrostatic spinning aqueous solution into an injector, transferring the injector to an injection device for electrostatic spinning, and adjusting injection parameters; coating an aluminum foil on the receiving roller, connecting the receiving end with the negative pole of a power supply, and connecting the needle of the injector with the positive pole of the power supply; arranging a mask at the receiving end, starting a receiving end rolling device and an emitting end translation device, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the power supply of the emitting end to reach a required voltage, and obtaining the electrostatic spinning film with the first heavy fluorescent pattern.
Electrospinning as described herein is a well known method in the art, but the use of electrospinning herein allows for a large specific surface area fast response of the electrospinning to light and humidity. In the electrostatic spinning process, an electrostatic spinning needle with the inner diameter of 1mm is adopted, and an aluminum foil is preferably adopted at a receiving end; the electrostatic spinning voltage is 10-20 kV, the receiving end voltage is-1.5 kV to-2.5 kV, the receiving end distance is 15-20 cm, and the spinning speed is 8-15 mu m.min -1 (ii) a The concentration of the electrostatic spinning aqueous solution is 5-15 wt%.
Through the electrostatic spinning and the arrangement of the mask, the electrostatic spinning film with the first heavy fluorescent pattern is prepared; the first heavy fluorescent patterns can be randomly arranged according to requirements and correspond to the patterns of the mask.
According to the invention, a second anti-counterfeiting pattern is drawn on the surface of the electrostatic spinning film so as to obtain a reversible humidity response fluorescence color-changing system. In the application, the second anti-counterfeiting pattern is prepared from waterproof paint, and the fluorescence of the pattern with a specific shape in an original dry state can be realized. The process comprises the following steps:
mixing a waterproof material with an organic solvent to obtain a waterproof coating;
and transferring the target pattern to the surface of the electrostatic spinning film by using a mask method or a stamping method and using waterproof paint, and drying the electrostatic spinning film after the pattern is transferred, so as to obtain the reversible color-changing fluorescent double anti-counterfeiting pattern.
In the above process, the waterproof material is well known to those skilled in the art, and is exemplified by one or more selected from paraffin, polymethacrylic acid, polyethylene wax, polystyrene, polyvinyl fluoride and vaseline; the organic solvent is well known to those skilled in the art, and exemplified by one selected from the group consisting of diethyl ether, acetone, n-hexane, toluene, ethyl acetate, cyclohexane, decahydronaphthalene, dichloromethane, chloroform, and the like. The transfer method is performed in a manner well known to those skilled in the art, and the present application is not particularly limited. The drying temperature is 25-60 ℃ to ensure that the waterproof layer is more compact.
The application also provides a reversible humidity-response fluorescence color-changing system prepared by the method, which consists of an electrostatic spinning film with a first heavy fluorescent pattern and a second heavy anti-counterfeiting pattern compounded on the surface of the first heavy fluorescent pattern, wherein the electrostatic spinning film comprises an anionic polyelectrolyte and fluorescent molecules, the fluorescent molecules are fluorescent molecules with color changed after receiving protons, and the second heavy anti-counterfeiting pattern is drawn by waterproof paint.
For the humidity-responsive fluorescence color-changing system provided by the application, the first double-fluorescence anti-counterfeiting pattern and the second double-fluorescence humidity-responsive anti-counterfeiting pattern can be optionally arranged according to requirements, and the application is not particularly limited.
The application also provides application of the reversible humidity response fluorescence color changing system in the anti-counterfeiting field.
The application provides a reversible humidity response fluorescence discoloration system constructs the stimulus response system with the help of fluorescence molecule and polymer substrate, can be encrypted twice on the basis of original fluorescence pattern, do not have the pattern under low humidity visible light, present first heavy fluorescence pattern under the ultraviolet lamp, can observe second heavy fluorescence pattern after carrying out local humidity promotion action, and the reversible humidity response fluorescence discoloration system that this application provided has the specificity to water and the quick humidity response of fluorescence discoloration reversible changes colour, the complexity of fluorescence anti-fake pattern is further promoted in this kind of design, security and convenience, this kind of stimulus response fluorescence multiple anti-fake has pioneering meaning, and have positive advancing action to the upgrading of fluorescence anti-fake technique.
For further understanding of the present invention, the reversible humidity-responsive fluorescence color-changing system, the preparation method and the application thereof provided by the present invention are described below with reference to the following examples, and the scope of the present invention is not limited by the following examples.
Example 1
A preparation method of a reversible color-changing fluorescent double anti-counterfeiting fiber comprises the following steps:
1) Preparation of Polymer matrix polyacrylic acid
(1) Weighing dissolved medicine
Respectively weighing 1.000g +/-0.001 g of acrylic acid and 0.040g +/-0.001 g of ammonium persulfate, adding into 4ml of deionized water, and shaking until the acrylic acid and the ammonium persulfate are fully dissolved;
(2) synthesis and purification of polymeric polyacrylic acid
Removing oxygen in the solution by bubbling nitrogen, preserving heat for 6 hours at 60 ℃ in nitrogen atmosphere, injecting the reacted solution into a dialysis bag with a pore diameter of 3000 after the reaction is finished, sealing, and dialyzing by putting the dialysis bag into deionized water to remove residual initiator, monomer and other impurities; carrying out dialysis for three days, replacing deionized water every 24h, carrying out freeze drying after dialysis to obtain purified polyacrylic acid powder, and carrying out vacuum drying and storage;
2) Electrostatic spinning preparation of humidity response fluorescent fiber
(1) Weighing dissolved medicine
Respectively weighing 0.800g +/-0.001 g of the synthesized and purified polyacrylic acid and 0.002g +/-0.0001 g of tetrapyridyl tetraphenylethylene, adding the weighed materials into 9.2g of deionized water, and fully and slowly stirring the materials for three days to obtain an electrostatic spinning aqueous solution with the solid content of 8 wt%;
(2) electrostatic spinning
The electrostatic spinning adopts an electrostatic spinning needle with the inner diameter of 1mm,the receiving end is an aluminum foil, the electrostatic spinning voltage is 15kV, and the voltage of the receiving end is-2 kV; the receiving distance is 18cm, and the spinning speed is 10 mu L min -1 (ii) a In the electrostatic spinning process, a mask can be arranged at a receiving end to realize the drawing of the first heavy fluorescent pattern;
firstly, sucking an electrostatic spinning aqueous solution into an injector, removing bubbles in the electrostatic spinning aqueous solution, transferring the injector to an electrostatic spinning injection device, and adjusting injection parameters; coating an aluminum foil on the receiving roller, flattening and dedusting, connecting the receiving end with a negative electrode of a power supply, and connecting the needle of the injector with a positive electrode of the power supply; arranging a mask on a receiving end, starting a receiving end rolling device and a transmitting end translation device, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the voltage of the transmitting end to reach a required voltage, and obtaining the electrostatic spinning film on an aluminum foil of the receiving end;
3) Drawing of second anti-counterfeiting pattern
(1) Weighing dissolved medicine
Weighing 0.500g of +/-0.001 g of paraffin, and dissolving in 20ml of diethyl ether to prepare a hydrophobic coating;
(2) pattern transfer
Transferring the target pattern onto the prepared electrostatic spinning film by using a mask method or a stamping method, after ether naturally volatilizes, placing the electrostatic spinning film with the transferred pattern in a vacuum drying oven for two hours at 50 ℃, and enabling the hydrophobic pattern to be compact to obtain the electrostatic spinning film with double patterns.
4) Detection, analysis and characterization of; the method comprises the following specific steps:
detecting, analyzing and representing the morphology, the fluorescence performance, the reaction of the fluorescent color change process, the response speed of the fluorescent color change and the like of the prepared electrostatic spinning film with the double patterns;
carrying out morphology analysis on the electrostatic spinning film by using a scanning electron microscope;
performing functional group analysis on the electrostatic spinning film by using a Fourier infrared spectrometer;
performing fluorescence performance analysis on the electrostatic spinning film by using an ultraviolet fluorescence spectrophotometer on fluorescence spectrum, fluorescence stimulation response performance, fluorescence color change repeatability, selectivity and the like;
the electrochemical workstation was used to analyze the color change response speed of the electrospun film.
FIG. 1 is a scanning electron micrograph (FIG. 1 a) and fiber distribution (FIG. 1 b) of an electrospun fiber film prepared in example 1; as can be seen from the figure, the spinning fibers are uniform, the diameter is about 200nm, the surfaces of the fibers are smooth and distributed randomly, and the fibers are mutually lapped to form micropores, so that the rapid circulation of water molecules can be realized, and the rapid humidity response can be realized.
FIG. 2 is a comparison graph of the IR spectra of the electrospun fiber film with dual patterns prepared in example 1 in dry and wet environments; as can be seen, the film can absorb water in a humid environment, and the polyacrylic acid substrate is quickly ionized to generate H + From the corresponding FT-IR spectrum, the C = O stretching vibration signal is 1710cm from COOH -1 Signal change to COO - 1635cm -1 The signal, while the tetrapyridylethylene is protonated to form 4H-TPE-4Py 4+ And the water-induced fluorescence color change is realized.
Fig. 3 is a graph showing the change of fluorescence color and fluorescence intensity of the electrospun fiber film prepared in example 1 in different humidity environments. As can be seen from the figure, the fluorescence color shows obvious change under different relative humidity environments, so that the film can generate obvious visual signals in response to the stimulation of water, the fluorescence color and the fluorescence intensity both show great change along with the increase of the environmental humidity, and the visual effect observed by human eyes is enhanced through the cooperation of the fluorescence color and the fluorescence intensity.
FIG. 4 is a graph of the fluorescence spectra of the electrospun fiber film with dual patterns prepared in example 1 cycling in a dry-wet environment; it can be seen from the figure that the prepared electrospun fiber film has stable change of fluorescence color and fluorescence intensity in multiple cycles of dry-wet environment.
FIG. 5 is a graph of the fluorescence spectra of electrospun fiber films with dual patterns prepared in example 1 in different solvent fumigations; as can be seen, the electrospun fiber membrane only produces specific response to water under the fumigating effect of different solvents.
FIG. 6 is a graph showing the current change under constant voltage conditions of the electrospun fiber film having a double pattern prepared in example 1; as can be seen from the figure, the electrostatic spinning fiber film has the advantages of rapid humidity response and rapid fluorescence recovery, and can realize real-time humidity sensing and rapid anti-counterfeiting authentication.
Fig. 7 is a fluorescent photograph of the first heavy fluorescent pattern drawn by electrospinning with double patterns and the second heavy fluorescent pattern obtained after transferring the anti-counterfeit pattern prepared in example 1 under visible light and ultraviolet light; as can be seen, the fluorescent pattern was not observed under visible light (fig. 7 a), the first heavy blue fluorescent pattern was observed under ultraviolet light under dry conditions (fig. 7 b), and by increasing the ambient humidity (haar), it was observed that a part of the first heavy fluorescent pattern remained the original color and another part turned yellow-green, showing a double fluorescent pattern (fig. 7 c).
Example 2
A preparation method of a reversible color-changing fluorescent double anti-counterfeiting fiber comprises the following steps:
1) Preparation of Polymer substrate polymethacrylic acid
(1) Weighing dissolved medicine
Respectively weighing 1.500g +/-0.001 g of methacrylic acid and 0.060g +/-0.001 g of ammonium persulfate, adding into 6ml of deionized water, and shaking to fully dissolve;
(2) synthesis and purification of polymer polymethacrylic acid
Removing oxygen in the solution by bubbling nitrogen, and keeping the temperature of the solution at 80 ℃ for 6 hours in the nitrogen atmosphere; after the reaction is finished, injecting the solution after the reaction into a dialysis bag with the aperture of 3000, sealing, and putting the dialysis bag into deionized water for dialysis to remove residual initiator, monomers and other impurities; the dialysis process is carried out for three days, and the deionized water is replaced every 24 hours; after dialysis, freeze drying is carried out to obtain purified polymethacrylic acid powder, and the powder is dried and stored in vacuum;
2) Preparation of fluorescent Unit tetra (4-pyridylbiphenyl) ethylene
(1) Weighing dissolved medicine
0.0648 g. + -. 0.0005g of tetrakis (4-bromophenyl) ethylene, 0.0123 g. + -. 0.0005g of pyridine-4-boronic acid, 0.022 g. + -. 0.001g of palladium acetate and 0.028 g. + -. 0.001g of tricyclohexylphosphine were weighed into a 50mL three-necked flask equipped with a reflux condenser, respectively; then 20mL of 1, 4-dioxane and 1mL of an aqueous solution of potassium phosphate (the content of potassium phosphate is 0.021g +/-0.001 g) were added to the flask under argon;
(2) synthesis of tetra (4-pyridylbiphenyl) ethylene
Removing oxygen in the reaction system by a freeze-thaw method for three times, and heating the mixture under reflux for 80 hours under argon; after removing the volatile solvent using a rotary evaporator, 10mL of deionized water was added and extracted three times with 20mL of chloroform; washing the collected organic layer with a saturated potassium carbonate aqueous solution and deionized water, and drying with anhydrous sodium sulfate; after removing the solvent using a rotary evaporator, the resulting crude product was purified by silica gel column chromatography using a methanol/chloroform mixed solvent (volume ratio 1;
3) Electrostatic spinning preparation of humidity response fluorescent fiber
(1) Weighing dissolved medicine
Respectively weighing 1.000g +/-0.001 g of the synthesized and purified polymethacrylic acid and 0.002g +/-0.0001 g of the synthesized and purified tetra (4-pyridylbiphenyl) ethylene, adding into 9.0 g of deionized water, and fully and slowly stirring for three days to obtain an electrostatic spinning aqueous solution with the solid content of 10 wt%;
(2) electrostatic spinning
Electrostatic spinning adopts an electrostatic spinning needle with the inner diameter of 1mm, the receiving end is an aluminum foil, the electrostatic spinning voltage is 17kV, and the voltage of the receiving end is-2 kV; the receiving distance is 18cm, and the spinning speed is 10 mu L.min -1 . In the electrostatic spinning process, a mask can be arranged at a receiving end to realize the drawing of the first heavy fluorescent pattern;
firstly, sucking a spinning solution into an injector, removing bubbles in the spinning solution, transferring the injector to an injection device for electrostatic spinning, and adjusting injection parameters; coating an aluminum foil on the receiving roller, flattening and dedusting, connecting the receiving end with a negative electrode of a power supply, and connecting the needle of the injector with a positive electrode of the power supply; arranging a mask at a receiving end, starting a receiving end rolling device and an emitting end translation device, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the power supply of the emitting end to reach a required voltage, and obtaining the electrostatic spinning film on the aluminum foil of the receiving end;
4) Drawing of secondary anti-counterfeiting pattern
(1) Weighing dissolved medicine
Weighing 0.500g +/-0.001 g of polymethyl methacrylate, and dissolving in 15ml of acetone to prepare a hydrophobic coating;
(2) pattern transfer
And transferring the target pattern onto the prepared electrostatic spinning film by using a mask method or a stamping method, and after acetone is naturally volatilized, placing the electrostatic spinning film with the transferred pattern into a vacuum drying oven for storage for two hours at the temperature of 60 ℃ to ensure that the hydrophobic pattern is compact.
Example 3
A preparation method of a reversible color-changing fluorescent double anti-counterfeiting fiber comprises the following steps:
1) Preparation of Polymer substrate Poly (2-acrylamido-2-methylpropanesulfonic acid)
(1) Weighing dissolved medicine
Respectively weighing 1.000g +/-0.001 g of 2-acrylamide-2-methylpropanesulfonic acid and 0.040g +/-0.001 g of ammonium persulfate, adding into 4ml of deionized water, and shaking to fully dissolve;
(2) synthesis and purification of polymer poly (2-acrylamido-2-methylpropanesulfonic acid)
Removing oxygen in the solution by bubbling nitrogen, preserving heat for 6h at 60 ℃ in nitrogen atmosphere, after the reaction is finished, injecting the solution after the reaction into a dialysis bag with a hole diameter of 3000, sealing, putting the dialysis bag into deionized water for dialysis, removing residual initiator, monomer and other impurities, carrying out the dialysis process for three days, replacing the deionized water every 24h, carrying out freeze drying after the dialysis is finished, obtaining purified poly (2-acrylamido-2-methylpropanesulfonic acid) powder, and carrying out vacuum drying and storage;
3) Electrostatic spinning preparation of humidity response fluorescent fiber
(1) Weighing dissolved medicine
0.600g +/-0.001 g of the synthesized and purified poly (2-acrylamide-2-methylpropanesulfonic acid) and 0.002g +/-0.0001 g of tetra (4-pyridine vinyl phenyl) ethylene are respectively weighed and added into 9.4g of deionized water, and the mixture is fully and slowly stirred for three days to obtain an electrostatic spinning aqueous solution with the solid content of 8 weight percent;
(2) electrostatic spinning
Electrostatic spinning adopts an electrostatic spinning needle with the inner diameter of 1mm, the receiving end is an aluminum foil, the electrostatic spinning voltage is 20kV, and the voltage of the receiving end is-2 kV; the receiving distance is 18cm, and the spinning speed is 15 mu L min -1 (ii) a In the electrostatic spinning process, a mask can be arranged at a receiving end to realize the drawing of the first heavy fluorescent pattern;
firstly, sucking a spinning solution into an injector, removing bubbles in the spinning solution, transferring the injector to an injection device for electrostatic spinning, and adjusting injection parameters; coating an aluminum foil on the receiving roller, flattening and dedusting, connecting the receiving end with a negative electrode of a power supply, and connecting the needle of the injector with a positive electrode of the power supply; arranging a mask at a receiving end, starting a receiving end rolling device and an emitting end translation device, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the power supply of the emitting end to reach a required voltage, and obtaining the electrostatic spinning film on the aluminum foil of the receiving end;
4) Drawing of secondary anti-counterfeiting pattern
(1) Weighing dissolved medicine
Weighing 0.500g +/-0.001 g of vaseline, and dissolving in 20ml of normal hexane to prepare a hydrophobic coating;
(2) pattern transfer
Transferring the target pattern onto the prepared electrostatic spinning film by using a mask method or a stamping method, naturally volatilizing n-hexane, and storing the electrostatic spinning film after pattern transfer in a vacuum drying oven at 30 ℃ for two hours to ensure that the hydrophobic pattern is compact.
Example 4
A preparation method of a reversible color-changing fluorescent double anti-counterfeiting fiber comprises the following steps:
1) Preparation of Polymer matrix polyacrylic acid
(1) Weighing dissolved medicine
Respectively weighing 1.000g +/-0.001 g of acrylic acid and 0.040g +/-0.001 g of ammonium persulfate, adding into 4ml of deionized water, and shaking until the acrylic acid and the ammonium persulfate are fully dissolved;
(2) synthesis and purification of polymeric polyacrylic acid
Removing oxygen in the solution by bubbling nitrogen, preserving heat for 6 hours at 60 ℃ in nitrogen atmosphere, injecting the reacted solution into a dialysis bag with a pore diameter of 3000 after the reaction is finished, sealing, and dialyzing by putting the dialysis bag into deionized water to remove residual initiator, monomer and other impurities; carrying out dialysis for three days, replacing deionized water every 24h, carrying out freeze drying after dialysis to obtain purified polyacrylic acid powder, and carrying out vacuum drying and storage;
2) Preparation of fluorescent Unit (2Z,2 'Z) -2,2' - ((1, 4-phenylene) bis (3- (4-pyridylphenyl) acrylonitrile)
(1) Weighing dissolved medicine
Respectively weighing 0.0642g +/-0.0005 g of terephthalonitrile, 0.183g +/-0.001 g of 4- (4-pyridyl) benzaldehyde and 0.1344g +/-0.0005 g of potassium tert-butoxide, respectively adding into a vial, adding 2ml of tert-butanol, and fully shaking for dissolving;
(2) synthesis of (2Z,2 'Z) -2,2' - ((1, 4-phenylene) bis (3- (4-pyridylphenyl) acrylonitrile)
Fully mixing a p-phenylenediacetonitrile solution and a 4- (4-pyridyl) benzaldehyde solution, adding a potassium tert-butoxide solution, fully shaking and stirring, preserving heat at 40 ℃ for 1h, filtering the mixture, removing tert-butanol by using a rotary evaporator, adding hot ethanol, fully shaking and dispersing, centrifuging, removing supernatant, and repeating for three times; vacuum drying in oven at room temperature for 24 hr to obtain yellowish powder;
3) Electrostatic spinning preparation of humidity response fluorescent fiber
(1) Weighing dissolved medicine
0.800 g. + -. 0.001g of the above-mentioned synthesized and purified polyacrylic acid and 0.002 g. + -. 0.0001g of the above-mentioned synthesized and purified (2Z, 2 'Z) -2,2' - ((1, 4-phenylene) bis (3- (4-pyridylphenyl) acrylonitrile) were weighed respectively, added to 9.2g of deionized water, and sufficiently and slowly stirred for three days to obtain an electrospinning aqueous solution having a solid content of 8% by weight;
(2) electrostatic spinning
The electrostatic spinning adopts an electrostatic spinning needle with the inner diameter of 1mm, and the receiving end is an aluminum foil. The electrostatic spinning voltage is 15kV, wherein the voltage of a receiving end is-2 kV; the receiving distance is 18cm, and the spinning speed is 10 mu L.min -1 . In the electrostatic spinning process, a mask can be arranged at a receiving end to realize the drawing of the first heavy fluorescent pattern;
firstly, sucking a spinning solution into an injector, removing bubbles in the spinning solution, transferring the injector to an injection device for electrostatic spinning, and adjusting injection parameters; coating an aluminum foil on a receiving roller, flattening and dedusting, connecting a receiving end with a negative electrode of a power supply, and connecting a syringe needle with a positive electrode of the power supply; starting a receiving end rolling device, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the power supply of the injector to reach a required voltage, and obtaining the electrostatic spinning film on the aluminum foil at the receiving end;
4) Drawing of second anti-counterfeiting pattern
(1) Weighing dissolved medicine
Weighing 0.500g of +/-0.001 g of paraffin, and dissolving in 20ml of diethyl ether to prepare a hydrophobic coating;
(2) pattern transfer
Transferring the target pattern onto the prepared electrostatic spinning film by using a mask method or a stamping method, and after ether is naturally volatilized, placing the electrostatic spinning film with the transferred pattern into a vacuum drying oven for storage for two hours at the temperature of 60 ℃ to ensure that the hydrophobic pattern is compact.
Example 5
1) Electrostatic spinning preparation of humidity response fluorescent fiber
(1) Weighing dissolved medicine
0.800g +/-0.01 g of a commercially available polyacrylic acid aqueous solution with the solid content of 50% and the molecular weight of 3000, 0.600g +/-0.01 g of commercially available polyvinylpyrrolidone with the molecular weight of 40000 and 0.002g +/-0.0001 g of tetrapyridyl tetraphenylethylene are respectively weighed and added into 8.6g of deionized water, and the mixture is fully and slowly stirred for three days to obtain an electrostatic spinning aqueous solution with the solid content of 10 wt%;
(2) electrostatic spinning
The electrostatic spinning adopts an electrostatic spinning needle with the inner diameter of 1mm, and the receiving end is an aluminum foil. The electrostatic spinning voltage is 15kV, wherein the voltage of a receiving end is-2 kV; the receiving distance is 18cm, and the spinning speed is 15 mu L.min -1 In the electrostatic spinning process, a mask can be arranged at a receiving end to realize the drawing of the first heavy fluorescent pattern;
firstly, sucking a spinning solution into an injector, removing bubbles in the spinning solution, transferring the injector to an injection device for electrostatic spinning, and adjusting injection parameters; coating an aluminum foil on the receiving roller, flattening and dedusting, connecting the receiving end with a negative electrode of a power supply, and connecting the needle of the injector with a positive electrode of the power supply; starting a receiving end rolling device, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the power supply of an injector to reach a required voltage, and obtaining the electrostatic spinning film on the aluminum foil at the receiving end;
2) Drawing of second anti-counterfeiting pattern
(1) Weighing dissolved medicine
Weighing 0.500g of +/-0.001 g of paraffin, and dissolving in 20ml of diethyl ether to prepare a hydrophobic coating;
(2) pattern transfer
Transferring the target pattern onto the prepared electrostatic spinning film by using a mask method or a stamping method, and after ether is naturally volatilized, placing the electrostatic spinning film with the transferred pattern into a vacuum drying oven for two hours at 50 ℃ to ensure that the hydrophobic pattern is compact.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A preparation method of a reversible humidity-response fluorescent color-changing system comprises the following steps:
a) Mixing anionic polyelectrolyte, fluorescent molecules and water to obtain an electrostatic spinning aqueous solution; the fluorescent molecules are fluorescent molecules with color changed after receiving protons;
b) Performing electrostatic spinning on the electrostatic spinning aqueous solution, and arranging a mask at a receiving end to draw a first heavy fluorescent pattern to obtain an electrostatic spinning film with the first heavy fluorescent pattern;
c) And B) drawing a second anti-counterfeiting pattern on the surface of the electrostatic spinning film obtained in the step B) by using the waterproof coating to obtain a reversible humidity response fluorescent color-changing system.
2. The method of claim 1, wherein the anionic polyelectrolyte is polyacrylic acid, polymethacrylic acid, or poly (2-acrylamido-2-methylpropanesulfonic acid); the fluorescent molecule is a compound with an amino group, an imino group and a pyridyl group directly connected to a conjugated skeleton, specifically, the fluorescent molecule is selected from tetra (4-pyridine biphenyl) ethylene, tetra (4-pyridine vinyl phenyl) ethylene or (2Z, 2 'Z) -2,2' - ((1, 4-phenylene) bis (3- (4-pyridyl phenyl) acrylonitrile), the waterproof coating comprises a waterproof material and a solvent, the waterproof material is selected from one or more of paraffin, polymethacrylic acid, polyethylene wax, polystyrene, polyvinyl fluoride and vaseline, and the mass ratio of the anionic polyelectrolyte to the fluorescent molecule is (500-1000): 1.
3. The preparation method according to claim 1, wherein the step of electrospinning specifically comprises:
sucking the electrostatic spinning aqueous solution into an injector, transferring the injector to an injection device for electrostatic spinning, and adjusting injection parameters; coating an aluminum foil on the receiving roller, connecting the receiving end with the negative pole of a power supply, and connecting the needle of the injector with the positive pole of the power supply; arranging a mask at the receiving end, starting a rolling device at the receiving end and a translation mode at the transmitting end, starting a high-voltage power supply, adjusting the voltage of the receiving end to reach an expected value, then starting an injection pump and gradually adjusting the power supply at the transmitting end to reach a required voltage, and obtaining the electrostatic spinning film with the first heavy fluorescent pattern.
4. The method according to claim 1 or 3, wherein the voltage of said electrospinning is 10 to 20kV, the voltage of receiving end is-1.5 kV to-2.5 kV, the distance of receiving end is 15 to 20cm, and the spinning speed is 8 to 15 μm-min -1 (ii) a The concentration of the electrostatic spinning aqueous solution is 5-15 wt%.
5. The method of claim 1 or 3, wherein the diameter of the spun fiber in the electrospun film is 200 to 300nm.
6. The method according to claim 1, wherein step C) is in particular:
mixing a waterproof material with an organic solvent to obtain a waterproof coating; the waterproof material is selected from one or more of paraffin, polymethacrylic acid, polyethylene wax, polystyrene, polyvinyl fluoride and vaseline;
and transferring the target pattern onto the surface of the electrostatic spinning film by using a mask method or a stamping method and using waterproof paint, and drying the electrostatic spinning film after the pattern is transferred to obtain the reversible color-changing fluorescent double anti-counterfeiting pattern.
7. The method according to any one of claims 1 to 6, wherein the electrospinning aqueous solution further comprises an auxiliary polymer selected from one or more of polyvinylpyrrolidone, polyvinyl alcohol and polyethylene glycol.
8. A reversible humidity-response fluorescent color-changing system comprises an electrostatic spinning film with a first heavy fluorescent pattern and a second heavy anti-counterfeiting pattern compounded on the surface of the first heavy fluorescent pattern, wherein the electrostatic spinning film comprises anionic polyelectrolyte and fluorescent molecules, the fluorescent molecules are fluorescent molecules with color changing after receiving protons, and the second heavy anti-counterfeiting pattern is obtained by drawing waterproof paint.
9. The system of claim 1, wherein the electrospun film further comprises an auxiliary polymer selected from one or more of polyvinylpyrrolidone, polyvinyl alcohol, and polyethylene glycol.
10. Use of the reversible humidity-responsive fluorescent color-changing system prepared by the preparation method of any one of claims 1 to 7 or the reversible humidity-responsive fluorescent color-changing system of any one of claims 8 to 9 in the field of anti-counterfeiting.
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| CN116254615B (en) * | 2023-05-15 | 2023-08-04 | 诺一迈尔（苏州）医学科技有限公司 | Preparation method of endometrium repair membrane and prepared endometrium repair membrane |
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