Preparation method of photoresponsive thin film material, photoresponsive thin film material, ultraviolet light monitoring device and system

Abstract

The application provides a preparation method of a light response thin film material, the light response thin film material, an ultraviolet light monitoring device and a system. The method comprises the following steps: adding 4,4'-dihydroxyhexyloxy azobenzene into a polymer obtained by polymerization of a dihydroxy oligomer and a diisocyanate-based monomer to obtain polyurethane containing an azobenzene group; dissolving the polyurethane and a piezoelectric polymer in a high-boiling-point solvent to obtain an electrospinning solution; and performing electrospinning on the electrospinning solution to obtain the light response thin film material. The 4,4'-dihydroxyhexyloxy azobenzene containing a six-carbon spacer is added as a chain extender into the polymer of the dihydroxy oligomer and the diisocyanate-based monomer to obtain the ultraviolet light response polyurethane containing the azobenzene group. Furthermore, the light response thin film material with better flexibility, better mechanical properties and good ultraviolet light response can be prepared by combining the polyurethane and the piezoelectric polymer. The preparation process of the light response thin film material is simple, and the preparation cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric sensing, in particular to a preparation method of a light-responsive thin film material, the light-responsive thin film material, an ultraviolet light monitoring device and a system. BACKGROUND

[0002] Ultraviolet light is ubiquitous in daily life, both harmful and useful. In the field of health protection, ultraviolet light in sunlight can harm the human body, among which UVA (wavelength 320-400 nm) can accelerate skin aging, cause tanning and even cause skin cancer; UVB (wavelength 280-320 nm) can cause skin to appear red spots, edema and other phenomena. In the field of medical health, appropriate UVB irradiation can treat some skin diseases. At the same time, ultraviolet light has the effect of sterilization and disinfection, so it has wide application in water purification, preservation and other fields. Ultraviolet light monitoring is of great significance in the fields of health protection, medical health, electrical equipment health management, environmental protection monitoring and pollutant analysis.

[0003] Traditional ultraviolet light monitoring devices usually include two types of photoelectric ultraviolet light monitoring devices and photochromic ultraviolet light monitoring devices. Photoelectric ultraviolet light monitoring devices generally use semiconductors as response elements to convert ultraviolet light into electrical signals for output, and have the advantages of high test precision, high sensitivity and fast response speed, but photoelectric ultraviolet light monitoring devices are not flexible and have high production costs, so they are difficult to be widely used in daily life. Photochromic ultraviolet light monitoring devices use organic matter containing ultraviolet response groups such as azobenzene as response elements, which can determine the irradiation dose of ultraviolet light based on the color change of the response elements, and have the advantages of low cost, good flexibility and good combination with the human body, but photochromic ultraviolet light monitoring devices cannot output the intensity of ultraviolet light in real time, and the test results have large errors, so they can only be used for qualitative measurement.

[0004] In recent years, a method of combining ultraviolet light responsive organic material azobenzene with high polymer piezoelectric material to prepare a flexible ultraviolet light monitoring device has appeared. The ultraviolet light monitoring device used in the above method has a low molecular weight, has a certain flexibility, but has poor mechanical properties and cannot be dynamically served. Moreover, the above ultraviolet light monitoring device can only output the intensity of ultraviolet light, and cannot realize cumulative testing to obtain the irradiation dose of ultraviolet light. Therefore, how to realize the flexible ultraviolet light monitoring device, dynamic service, and real-time monitoring of ultraviolet light intensity and irradiation dose is a technical problem to be solved in the field. SUMMARY

[0005] The application provides a preparation method of a light response thin film material, a light response thin film material, an ultraviolet light monitoring device and a system, and aims to solve the defects that the conventional ultraviolet light monitoring device cannot realize good flexibility, dynamic service and real-time monitoring of ultraviolet light intensity and irradiation dose, and realize good flexibility, dynamic service and real-time monitoring of ultraviolet light intensity and irradiation dose.

[0006] The application provides a preparation method of a light response thin film material.

[0007] 4,4'-dihydroxy hexyloxy azobenzene is obtained by reacting 4,4'-dihydroxy azobenzene, 6-bromo n-hexanol and a catalyst under alkaline conditions at a temperature of 100-160 DEG C for 12-24 hours;

[0008] The dihydroxy oligomer is mixed with a diisocyanate-based monomer, and the obtained mixture is prepolymerized at a temperature of 60-100 DEG C for 2 hours under a nitrogen atmosphere to obtain a polymer;

[0009] 4,4'-dihydroxy hexyloxy azobenzene is added to the polymer to obtain a polyurethane containing an azobenzene group;

[0010] The polyurethane and a piezoelectric polymer are dissolved in a high-boiling-point solvent to obtain an electrospinning solution;

[0011] Electrospinning is performed by using the electrospinning solution to obtain the light response thin film material.

[0012] According to the preparation method of the light response thin film material, the dihydroxy oligomer comprises one or more of polyethylene glycol, polytetrahydrofuran and polycaprolactone diol, and the molecular weight of the dihydroxy oligomer is between 500 g / mol and 3000 g / mol.

[0013] According to the preparation method of the light response thin film material, the diisocyanate-based monomer comprises one or more of toluene diisocyanate, diphenyl methane diisocyanate, hexamethylene diisocyanate and isoflurone diisocyanate.

[0014] According to the preparation method of the light response thin film material, the molar ratio of the dihydroxy oligomer to the diisocyanate-based monomer is between 1:1.2 and 1:5.

[0015] According to the preparation method of the light response thin film material, in the step of adding 4,4'-dihydroxy hexyloxy azobenzene to the polymer, the sum of the moles of 4,4'-dihydroxy hexyloxy azobenzene and the moles of the dihydroxy oligomer is equal to the moles of the diisocyanate-based monomer.

[0016] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0017] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0018] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0019] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0020] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0021] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0022] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0023] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0024] The preparation method of the light-responsive film material provided by the present application comprises the following steps: dissolving polyurethane and piezoelectric polymer in a high-boiling solvent; and the mass ratio of the polyurethane and the piezoelectric polymer is between 1:0.4 and 1:5.

[0025] The present invention provides a method for preparing a photoresponsive thin film material, a photoresponsive thin film material, an ultraviolet light monitoring device, and a system. The method comprises the following steps: reacting 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol, and a catalyst under alkaline conditions at a temperature range of 100-160°C for 12-24 hours to obtain 4,4'-dihydroxyhexyloxyazobenzene; mixing a dihydroxy oligomer with a diisocyanate monomer; prepolymerizing the obtained mixture at a temperature range of 60-100°C under a nitrogen atmosphere for 2 hours to obtain a polymer; adding 4,4'-dihydroxyhexyloxyazobenzene to the polymer to obtain a polyurethane containing an azobenzene group; dissolving the polyurethane and the piezoelectric polymer in a high boiling point solvent to obtain an electrospun polymer. Liquid is prepared and electrospinning is performed using the electrospinning liquid to obtain a light-responsive thin film material. By adding 4,4'-dihydroxyhexyloxyazobenzene containing a six-carbon spacer as a chain extender to a polymer of a dihydroxy oligomer and a diisocyanate monomer, a polyurethane containing azobenzene groups that responds to ultraviolet light can be obtained. Then, by combining the above polyurethane with a piezoelectric polymer, a light-responsive thin film material with better flexibility, better mechanical properties and good ultraviolet light response can be prepared. The preparation process of the above light-responsive thin film material is simple, no large-scale equipment is required during preparation, and the preparation cost is relatively low. It can provide technical support for the preparation of ultraviolet light monitoring devices that have good flexibility, can be dynamically used, and can monitor ultraviolet light irradiation dose in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is a schematic flow chart of the method for preparing the light-responsive thin film material provided by the present invention.

[0028] Figure 2 It is a schematic diagram of the molecular structure of polyurethane containing azobenzene groups in the preparation method of the light-responsive thin film material provided by the present invention.

[0029] Figure 3 This is a scanning electron microscope photograph of the light-responsive thin film material provided by the present invention.

[0030] Figure 4 It is a schematic flow chart of the preparation method of the ultraviolet light monitoring device provided by the present invention.

[0031] Figure 5 The graph is a current change rate-time curve of the ultraviolet light monitoring device provided by the present invention under irradiation of ultraviolet light of different intensities.

[0032] Figure 6 is one of the current rate of change-time graphs of the ultraviolet light monitoring device provided by the present application under different stretching and bending lengths under ultraviolet light intensity irradiation.

[0033] Figure 7 is the second of the current rate of change-time graphs of the ultraviolet light monitoring device provided by the present application under different stretching and bending lengths under ultraviolet light intensity irradiation.

[0034] Figure 8 is the current rate of change-time graph of the ultraviolet light monitoring device provided by the present application under the cyclic irradiation of ultraviolet light.

[0035] Figure 9 is a comparative chart of the response degree of the ultraviolet light monitoring device with different mass ratios of the polyurethane containing azobenzene groups and the piezoelectric polymer in Comparative Example 1 to the ultraviolet light. DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] The endpoints of the ranges and any values in the ranges disclosed herein are not limited to the precise values stated. The ranges and values should be construed to be approximations that allow for significant variation. Within each range, other values are contemplated and should be considered as falling within the scope of the present application. For ranges expressed in the context of a number of values, such as, for example, two to five, or, more generally, a first number to a second number, the first number and the second number are understood to be inclusive of the recited numbers.

[0038] In the description of the present application, the terms "first", "second", and the like are used to distinguish similar objects, and are not used to describe a particular order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a class, not limited to the number of objects, for example, the first object can be one or more. In addition, in the description of the present application, "and / or" means at least one of the connected objects, and the character " / ", generally means that the objects before and after are in a "or" relationship.

[0039] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "specific embodiments", or "some specific embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0040] In the present application, the instruments and the like not marked with the manufacturer are all conventional products that can be purchased through regular channels. The methods are all conventional methods unless otherwise specified, and the raw materials can be obtained from public commercial channels unless otherwise specified. The specific techniques or conditions not marked in the examples are carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0041] Figure 1 is a flowchart of the preparation method of the photoresponsive film material provided by the present application. As shown in Figure 1 , the method comprises the following steps: step 101, reacting 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol and a catalyst under alkaline conditions at a temperature in the range of 100-160°C for 12-24 hours to obtain 4,4'-dihydroxyhexyloxyazobenzene;

[0042] Step 102, mixing the dihydroxy oligomer with a diisocyanate-based monomer, and pre-polymerizing the obtained mixture under a nitrogen atmosphere at a temperature in the range of 60-100°C for 2 hours to obtain a polymer;

[0043] Step 103, adding 4,4'-dihydroxyhexyloxyazobenzene to the polymer to obtain azobenzene group-containing polyurethane;

[0044] Step 104, dissolving the polyurethane and the piezoelectric polymer in a high-boiling-point solvent to obtain an electrospinning solution, the boiling point of the high-boiling-point solvent being not less than 120°C;

[0045] Step 105, electrospinning the electrospinning solution to obtain the photoresponsive film material.

[0046] It should be noted that the azobenzene group-containing polyurethane (Az-TPU) in the embodiments of the present application is synthesized independently in the laboratory. Figure 2 is a schematic diagram of the molecular structure of the azobenzene group-containing polyurethane in the preparation method of the photoresponsive film material provided by the present application. The schematic diagram of the molecular structure of the azobenzene group-containing polyurethane is as follows:Figure 2 as shown.

[0047] In step 102, the reaction temperature of the dihydroxy oligomer and the diisocyanate-based monomer is selected to be between 60-100℃, because the polymerization reaction is slow at too low temperature, the dihydroxy oligomer and the diisocyanate-based monomer are difficult to polymerize, the high-boiling-point solution is easy to volatilize at too high temperature, and the system is easy to crosslink after adding the chain extender at too high temperature.

[0048] In step 102, the polymerization reaction of the mixture of the dihydroxy oligomer and the diisocyanate-based monomer can be completed in 2 hours at a temperature of 60-100℃ under a nitrogen atmosphere.

[0049] In step 103, the conjugation effect of the benzene ring on the hydroxyl group is large when the spacer length is too short, and the polymerization reaction is difficult to proceed; the azobenzene group is affected to increase in the stretching process when the spacer length is too long, and the dynamic response signal is greatly affected, therefore, 4,4'-dihydroxyhexyloxy azobenzene containing a six-carbon spacer is added to the polymer as a chain extender in the embodiment of the application.

[0050] In step 105, the hydrogen bonding and microphase separation of the polyurethane can provide excellent mechanical properties for the light-responsive thin film material. In the stretching and bending process, the soft segment of the polyurethane is greatly deformed, and the deformation amount of the light-responsive unit azobenzene and the piezoelectric phase is small. Therefore, the stretching and bending behavior has little effect on the ultraviolet light responsiveness test of the ultraviolet light monitoring device prepared based on the light-responsive thin film material, and the above device can complete the dynamic test.

[0051] Optionally, the mass ratio of the polyurethane to the piezoelectric polymer in step 104 is 1:0.4-1:5.

[0052] Preferably, the mass ratio of the polyurethane to the piezoelectric polymer in step 104 is 1:2.

[0053] Optionally, the thin film substrate subjected to electrospinning in step 105 is a fiber thin film substrate, and the fiber thin film substrate is prepared by a spinning method. The spinning method is selected from one of a wet spinning method, a dry spinning method, an electrospinning method and a microfluidic spinning method.

[0054] Preferably, the direct current voltage used in the process of electrospinning in step 105 is 8-15KV, and the electrospinning liquid propelling speed in the syringe is 0.5-1mL / h. The electrospinning liquid, preferably 1-2mL, is continuously spun to obtain the light-responsive thin film material with a desired thickness; the receiving device is a cylindrical roller, and the receiving rotation speed is preferably 500r / min-2800r / min.

[0055] Optionally, the catalyst in step 101 can be potassium iodide.

[0056] Optionally, the piezoelectric polymer in step 101 may include one or more of polyvinylidene difluoride (PVDF), polyacrylonitrile (PAN), and polydimethylsiloxane (PDMS).

[0057] As an optional embodiment, the dihydroxy oligomer includes one or more of polyethylene glycol, polytetrahydrofuran, and polycaprolactone diol, and the molecular weight of the dihydroxy oligomer is between 500 g / mol and 3000 g / mol.

[0058] It should be noted that in the examples of the present invention, dihydroxy oligomers with a certain molecular weight, such as polyethylene glycol, polytetrahydrofuran, and polycaprolactone diol, are selected to act as soft segments in the polymer, which can provide flexibility and improve the polymer's elongation at break. Furthermore, when the prepared photoresponsive film material is stretched, the soft segments can replace the hard segments and photoresponsive groups to extend, thereby reducing the impact of stretching on UV light monitoring.

[0059] As an optional embodiment, the diisocyanate-based monomer includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

[0060] It should be noted that in the embodiments of the present invention, diisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate are selected to act as hard segments in the polymer, which can make the polyurethane obtained by polymerization easier to achieve microphase separation, thereby improving the mechanical properties of the prepared photoresponsive film material.

[0061] As an optional embodiment, the molar ratio of the dihydroxy oligomer to the diisocyanate monomer is between 1:1.2 and 1:5.

[0062] As an optional embodiment, in the step of adding 4,4'-dihydroxyhexyloxyazobenzene to the polymer, the sum of the moles of 4,4'-dihydroxyhexyloxyazobenzene and the dihydroxy oligomer is equal to the mole of the diisocyanate monomer.

[0063] As an optional embodiment, in the step of dissolving the polyurethane and the piezoelectric polymer in a high-boiling-point solvent, the mass ratio of the polyurethane to the piezoelectric polymer is between 1:0.4 and 1:5.

[0064] As an optional embodiment, the photoresponsive thin film material is stored in an ionic solution; the ionic solution includes one or more of 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

[0065] In the embodiment of the present invention, 4,4'-dihydroxyazobenzene, 6-bromohexanol and a catalyst are placed under alkaline conditions and reacted in a temperature range of 100-160°C for 12-24 hours to obtain 4,4'-dihydroxyhexyloxyazobenzene, a dihydroxy oligomer is mixed with a diisocyanate monomer, and the resulting mixture is prepolymerized in a nitrogen atmosphere at a temperature range of 60-100°C for 2 hours to obtain a polymer, 4,4'-dihydroxyhexyloxyazobenzene is added to the polymer to obtain a polyurethane containing an azobenzene group, the polyurethane and the piezoelectric polymer are dissolved in a high boiling point solvent to obtain an electrospinning solution, and the electrospinning solution is used for electrostatic spinning to obtain The photoresponsive thin film material can be prepared by adding 4,4'-dihydroxyhexyloxyazobenzene containing a six-carbon spacer as a chain extender to a polymer of a dihydroxy oligomer and a diisocyanate monomer to obtain a polyurethane containing azobenzene groups that responds to ultraviolet light. The polyurethane can then be combined with a piezoelectric polymer to prepare a photoresponsive thin film material with better flexibility, better mechanical properties and good ultraviolet light response. The preparation process of the photoresponsive thin film material is simple, does not require the participation of large equipment during preparation, and has a relatively low preparation cost. It can provide technical support for the preparation of ultraviolet light monitoring devices that are flexible, can be dynamically used, and can monitor ultraviolet light irradiation dose in real time.

[0066] Based on the contents of the above embodiments, a photoresponsive thin film material is provided. The photoresponsive thin film material is prepared based on any of the above methods for preparing the photoresponsive thin film material.

[0067] Based on the contents of the above embodiments, an ultraviolet light monitoring device includes: a first packaging tape layer, a first conductive adhesive layer, a first wire layer, a light-responsive thin film material layer, a second wire layer, a second conductive adhesive layer, and a second packaging tape layer, which are arranged in order from top to bottom;

[0068] The photoresponsive thin film material in the photoresponsive thin film material layer is prepared based on any of the above methods for preparing the photoresponsive thin film material.

[0069] The present invention prepares a stretchable and foldable light-responsive film material by blending azobenzene-containing, ultraviolet-light-responsive, high-molecular-weight polyurethane with a piezoelectric polymer. The light-responsive film material is then immersed in an ionic solution and then packaged with a copper wire, a graphite-based acrylate tape, and a polyacrylate tape to prepare a ultraviolet light monitoring device.

[0070] The ultraviolet light monitoring device can convert the ultraviolet light signal into a voltage signal to realize ultraviolet light intensity detection, because the azobenzene groups in the light-responsive thin film material layer of the ultraviolet light monitoring device produce cis-trans isomerization and volume change under ultraviolet light irradiation, drive the molecular chain to shrink to produce photo-induced stress, and cause the piezoelectric polymer in the light-responsive thin film material layer to generate a voltage signal.

[0071] In some preferred embodiments, in the characterization of the ultraviolet light detection capability, the azobenzene produces cis-trans isomerization and volume change under ultraviolet light irradiation, drives the molecular chain to shrink to produce photo-induced stress, and causes the piezoelectric material to generate a voltage, so that the change in ultraviolet light intensity can be monitored by detecting the change in current or voltage.

[0072] On the other hand, the ultraviolet light monitoring device can realize dynamic service by using the excellent flexibility and mechanical properties of the polyurethane, and can produce a stable light response signal by using the photo-induced shrinkage effect of the azobenzene groups, and thus can realize the cumulative monitoring of ultraviolet light, thereby realizing the monitoring of the ultraviolet light irradiation dose.

[0073] The ultraviolet light monitoring device in the embodiments of the present application is prepared based on the above-mentioned light-responsive thin film material, and can realize good flexibility, dynamic service, and real-time monitoring of ultraviolet light intensity and irradiation dose of the ultraviolet light monitoring device by using the good flexibility, mechanical properties, and ultraviolet light response performance of the light-responsive thin film material, and has a wide application prospect.

[0074] In order to facilitate the understanding of the preparation method of the light-responsive thin film material, the ultraviolet light monitoring device, and the ultraviolet light monitoring system provided by the present application, the preparation method of the light-responsive thin film material, the ultraviolet light monitoring device, and the ultraviolet light monitoring system provided by the present application are specifically described below through multiple embodiments.

[0075] Embodiment 1

[0076] 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol, and a catalyst are placed in an alkaline condition and reacted at a temperature range of 100-160℃ for 12-24 hours to obtain 4,4'-dihydroxyhexyloxyazobenzene.

[0077] The dihydroxy oligomer is mixed with a diisocyanate-based monomer, and the obtained mixture is pre-polymerized at a temperature range of 60-100℃ for 2 hours under a nitrogen atmosphere to obtain a polymer.

[0078] 4,4'-dihydroxyhexyloxyazobenzene is added to the polymer to obtain a polyurethane containing azobenzene groups.

[0079] A certain amount of 4,4'-dihydroxyhexyloxy azobenzene and piezoelectric polymer are mixed and dissolved in a high-boiling-point solvent, stirred at 40-60°C for 4-12h by a magnetic stirrer, fully mixed and dissolved, and then a flexible light-responsive film material is prepared by a spinning method.

[0080] Optionally, the high-boiling-point solvent is any one or more of dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF) and N-methyl pyrrolidone (NMP).

[0081] Preferably, the high-boiling-point solvent is N,N-dimethylformamide.

[0082] Figure 3 Figure 1 is a scanning electron microscope photo of the light-responsive film material provided by the present application. The surface morphology of the light-responsive film material provided by the present application is shown in Figure 1. Figure 3

[0083] Example 2

[0084] Figure 4 Figure 2 is a flowchart of the preparation method of the ultraviolet light monitoring device provided by the present application. As shown in Figure 2, the preparation method of the ultraviolet light monitoring device comprises: weighing 600mg of polyurethane powder containing azobenzene groups and 400mg of piezoelectric polymer powder respectively with an analytical balance and pouring them into a glass bottle. Figure 4

[0085] Electrospinning is performed using the electrospinning solution. During electrospinning, the direct current voltage used is 15KV, and the solution in the syringe is pushed at a speed of 1mL / h, to obtain the light-responsive film material with the required thickness. The receiving device is a stainless steel cylindrical drum with an aluminum foil on the surface, and a servo motor is used to control the receiving speed to 2800r / min.

[0086] After spinning, the light-responsive film material is torn off with tweezers, and is air-dried overnight at room temperature and normal pressure. Finally, the light-responsive film material is cut into a 30mm×15mm sample for standby, and the long side is the orientation direction.

[0087] 10ml of 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate ionic liquid is placed in a glass bottle, the cut light-responsive film material is placed in the glass bottle and the ionic liquid is completely immersed, soaked for 12h, taken out with tweezers, and the ionic liquid on the surface of the light-responsive film material is absorbed with two pieces of filter paper, and dried in a 40°C vacuum oven for 2h.

[0088] ​​After the ionic liquid on the surface of the light-responsive thin film material is dried, the light-responsive thin film material is flattened on filter paper. A 1 mm x 30 mm copper wire is cut, and is pasted along the short edge direction at one end of the device. Then, a conductive double-sided adhesive tape is pasted as a conductive layer, and the excess part is cut off with scissors. Then, a polyacrylate adhesive tape is pasted as a packaging layer, and the excess part is cut off. Then, the light-responsive thin film material is turned over, and the same operation is performed on the other side to obtain the packaged ultraviolet light monitoring device.

[0089] In the case where the ultraviolet light monitoring device receives ultraviolet light irradiation, the electrostatic meter is used to obtain the light response signal generated by the ultraviolet light monitoring device, and the voltage amplifier and electronic equipment are used to obtain the ultraviolet light intensity and / or ultraviolet light irradiation dose corresponding to the light response signal, and then the ultraviolet light intensity and / or ultraviolet light irradiation dose can be sent to the user terminal through Bluetooth for the user to view.

[0090] Example 3

[0091] The light response test method and test results of the ultraviolet light monitoring device are included in this embodiment, including photo-induced stress test, static light response test, dynamic light response test, and ultraviolet light irradiation dose test.

[0092] 1) Static light response test

[0093] The ultraviolet light intensity detection and analysis system is composed of an electrostatic meter (6517B), an ultraviolet light source (365 nm), and a computer and other equipment. The specific operation is as follows: the ultraviolet light monitoring device is connected to the circuit, and under the irradiation of different ultraviolet light intensities, the electrostatic meter (6517B) detects the current change of the light response signal emitted by the ultraviolet light monitoring device in real time, and records the time, current, and ultraviolet light intensity data.

[0094] Figure 5 is the current change rate-time curve of the ultraviolet light monitoring device provided by the present application under the irradiation of different intensity ultraviolet light intensities. The current change rate-time curve of the ultraviolet light monitoring device under the irradiation of different intensity ultraviolet light intensities in this embodiment is as shown in Figure 5 .

[0095] The ultraviolet light intensity range that can be detected by the ultraviolet light monitoring device is 0.05~50mW·cm -2 , and the rise time (current change rate reaching the peak time) is 0.1 seconds. The ultraviolet light monitoring device provided by the present application has a wide wavelength detection range, fast response speed, good linear relationship in the response interval, and a smooth and straight response signal under continuous ultraviolet irradiation, which can meet the real-time monitoring requirements of the ultraviolet intensity and dose in sunlight.

[0096] 2) Dynamic light response test

[0097] The UV intensity detection analysis system is composed of electrometer (6517B), UV light source (365nm) and computer, etc. The UV monitoring device is stretched or bent under clamping condition using stepping motor to control the UV monitoring device. The UV response of the UV monitoring device is tested under dynamic conditions of stretching and bending.

[0098] Figure 6 is one of the current rate-time curves of the UV monitoring device provided by the present application under different stretching and bending lengths under UV light intensity irradiation. Figure 7 is the second of the current rate-time curves of the UV monitoring device provided by the present application under different stretching and bending lengths under UV light intensity irradiation. The UV monitoring device of the present embodiment has a current rate of 0.5 under 30mW / cm 2 The current rate-time curves under different stretching and bending lengths under UV light intensity irradiation are shown in Figure 6 and Figure 7 .

[0099] The stretching length refers to the percentage of the length difference after stretching to the original length. The bending curvature refers to the curvature of the UV monitoring device with a gage length of 2cm after bending. In the figure, UV refers to UV irradiation, UV+10% or UV+30% refers to the current signal generated by stretching the device to 110% or 130% of the original length at a frequency of 0.5Hz under UV irradiation of 30mW / cm 2 intensity (UV light on for 1s-off for 1s).

[0100] As shown in Figure 6 and Figure 7 , when the stretching length is below 30% and the bending curvature is below 1.4cm -1 , the UV monitoring device provided by the present application is less affected by the stretching and bending signals, which can be ignored.

[0101] 3) UV dose test

[0102] The UV monitoring device is connected to the circuit, and the device is irradiated with 10mW / cm 2 , 7.5mW / cm 2 , 4mW / cm 2 , 1mW / cm 2 , 0mW / cm 2 intensity in turn, each light intensity lasts for 5s, and the device is repeated for 400 cycles. The real-time current change is detected by the electrometer (6517B), and the time, current, UV intensity, etc. data are recorded.

[0103] Figure 8is a current rate of change-time curve of the ultraviolet light monitoring device under the cyclic irradiation of ultraviolet light. The current rate of change-time curve of the ultraviolet light monitoring device under 400 cycles of ultraviolet light irradiation is shown in Figure 8 .

[0104] The theoretical ultraviolet dose tested by the ultraviolet light monitoring device is calculated to be 402.27 kJ / m 2 by integrating the curve by origin and according to the calibrated ultraviolet intensity-current linear relationship in the static light responsiveness test. The actual irradiation dose is 405 kJ / m 2 , and the error is less than 1%.

[0105] Comparative Example 1

[0106] The mass ratio of the polyurethane containing azobenzene groups to the piezoelectric polymer was adjusted, and three groups of ultraviolet light monitoring devices with different proportions were prepared using the same process. The ultraviolet light responsiveness of each group of ultraviolet light monitoring devices was tested.

[0107] Figure 9 is a response degree comparison chart of the ultraviolet light monitoring device with different mass ratios of the polyurethane containing azobenzene groups to the piezoelectric polymer in Comparative Example 1. As shown in Figure 9 , the ultraviolet light monitoring device with a mass ratio of the polyurethane containing azobenzene groups to the piezoelectric polymer of 1:2 has the highest responsiveness and the best linear correlation, and the response degree is 0.93 nA / mW·cm -2 , R 2 =0.998.

[0108] Based on the above contents of each embodiment, an ultraviolet light monitoring system includes the ultraviolet light monitoring device, the electrometer, the voltage amplifier and the electronic device as above; the electrometer, the voltage amplifier and the electronic device are connected in sequence;

[0109] The electrometer is used to collect the light response signal generated by the ultraviolet light monitoring device and send the collected light response signal to the voltage amplifier;

[0110] The voltage amplifier is used to amplify the light response signal when receiving the light response signal sent by the electrometer, and send the amplified light response signal to the electronic device;

[0111] The electronic device is used to receive the amplified light response signal sent by the voltage amplifier, and obtain the intensity and / or irradiation dose of the ultraviolet light irradiated on the ultraviolet light monitoring device based on the amplified light response signal.

[0112] Optionally, the electronic device in the embodiment of the present application can be a microcontroller, preferably an Arduino microcontroller.

[0113] Optionally, the ultraviolet light monitoring system in the embodiment of the present application can further comprise a display device.

[0114] Optionally, the ultraviolet light monitoring system in the embodiment of the present application can further comprise a power supply, which can be used to supply power to the voltage amplifier and the electronic device.

[0115] When the ultraviolet light monitoring system performs ultraviolet light monitoring, the light response signal generated by the ultraviolet light monitoring device is amplified by the voltage amplifier, and then the amplified light response signal is input into the Arduino microcontroller, and through computer programming, the amplified light response signal is converted into corresponding ultraviolet light intensity and / or ultraviolet light irradiation dose.

[0116] The ultraviolet light monitoring system can also send the obtained ultraviolet light intensity and / or ultraviolet light irradiation dose to the user terminal through Bluetooth for the user to view.

[0117] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a photoresponsive thin film material, characterized in that: include: placing 4,4'-dihydroxyazobenzene, 6-bromohexanol and a catalyst under alkaline conditions and reacting at a temperature range of 100-160°C for 12-24 hours to obtain 4,4'-dihydroxyhexyloxyazobenzene; Mixing a dihydroxy oligomer with a diisocyanate monomer, and prepolymerizing the resulting mixture in a nitrogen atmosphere at a temperature range of 60-100° C. for 2 hours to obtain a polymer; adding the 4,4'-dihydroxyhexyloxyazobenzene as a chain extender to the polymer to obtain a polyurethane containing an azobenzene group; dissolving the polyurethane and the piezoelectric polymer in a high boiling point solvent to obtain an electrospinning solution, wherein the boiling point of the high boiling point solvent is not less than 120° C.; The electrospinning solution is used to perform electrostatic spinning to obtain the light-responsive film material.

2. The method for preparing a light-responsive thin film material according to claim 1, wherein: The dihydroxy oligomer includes one or more of polyethylene glycol, polytetrahydrofuran, and polycaprolactone diol, and the molecular weight of the dihydroxy oligomer is between 500 g / mol and 3000 g / mol.

3. The method for preparing a light-responsive thin film material according to claim 1, wherein: The diisocyanate-based monomer includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

4. The method for preparing a light-responsive thin film material according to claim 1, wherein: The molar ratio of the dihydroxy oligomer to the diisocyanate monomer is between 1:1.2 and 1:

5.

5. The method for preparing a light-responsive thin film material according to claim 4, wherein: In the step of adding the 4,4'-dihydroxyhexyloxyazobenzene to the polymer, the sum of the moles of the 4,4'-dihydroxyhexyloxyazobenzene and the dihydroxy oligomer is equal to the mole of the diisocyanate monomer.

6. The method for preparing a light-responsive thin film material according to claim 1, wherein: In the step of dissolving the polyurethane and the piezoelectric polymer in a high boiling point solvent, the mass ratio of the polyurethane to the piezoelectric polymer is between 1:0.4 and 1:

5.

7. The method for preparing a photoresponsive thin film material according to any one of claims 1 to 6, characterized in that: The photoresponsive thin film material is stored in an ionic solution; the ionic solution includes one or more of 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

8. A photoresponsive thin film material, characterized in that: include: The photoresponsive thin film material is prepared based on the method for preparing the photoresponsive thin film material according to any one of claims 1 to 7.

9. An ultraviolet light monitoring device, characterized in that: include: A first packaging tape layer, a first conductive adhesive layer, a first wire layer, a light-responsive thin film material layer, a second wire layer, a second conductive adhesive layer, and a second packaging tape layer are sequentially arranged from top to bottom; The photoresponsive thin film material in the photoresponsive thin film material layer is prepared based on the method for preparing the photoresponsive thin film material according to any one of claims 1 to 7.

10. An ultraviolet light monitoring system, characterized in that: include: The ultraviolet light monitoring device, electrometer, voltage amplifier and electronic device according to claim 9; the electrometer, the voltage amplifier and the electronic device are connected in sequence; The electrometer is used to collect the light response signal generated by the ultraviolet light monitoring device and send the collected light response signal to the voltage amplifier; The voltage amplifier is used to amplify the light response signal when receiving the light response signal sent by the electrometer, and send the amplified light response signal to the electronic device; The electronic device is used to obtain the intensity and / or irradiation dose of the ultraviolet light irradiated to the ultraviolet light monitoring device based on the amplified light response signal after receiving the amplified light response signal sent by the voltage amplifier.

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