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

Abstract

The invention provides a preparation method of a photoresponse thin film material, the photoresponse thin film material and an ultraviolet light monitoring device and system.The method comprises the steps that 4, 4 '-dihydroxy hexyloxy azobenzene is added into a polymer formed by polymerizing a dihydroxy oligomer and a diisocyanate-based monomer, polyurethane containing azobenzene groups is obtained, and the polyurethane containing the azobenzene groups is added into the polymer to obtain the photoresponse thin film material. The preparation method comprises the following steps: dissolving polyurethane and a piezoelectric polymer in a high-boiling-point solvent to obtain an electrospinning solution, and carrying out electrostatic spinning by adopting the electrospinning solution to obtain the photoresponse film material. According to the invention, 4, 4 '-dihydroxy hexyloxy azobenzene containing six-carbon spacer is used as a chain extender and is added into a polymer of a dihydroxy oligomer and a diisocyanate-based monomer to obtain azobenzene group-containing ultraviolet light response polyurethane, and then the polyurethane and a piezoelectric polymer are combined, so that the ultraviolet light response performance of the piezoelectric polymer is improved. The photoresponse thin film material with better flexibility, better mechanical property and good ultraviolet response is prepared, the preparation process of the photoresponse thin film material is simple, and the preparation cost is low.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric sensing technology, and in particular to a method for preparing a light-responsive thin film material, a light-responsive thin film material, an ultraviolet light monitoring device and a system. Background Art

[0002] Ultraviolet light can be seen everywhere in daily life, and it has both hazards and applications. In the field of health protection, ultraviolet rays in sunlight can cause harm to the human body. Among them, UVA (wavelength 320nm-400nm) can accelerate skin aging, cause tanning and even cause skin cancer; UVB (wavelength 280nm-320nm) can cause skin erythema, edema and other phenomena. In the field of medicine and health, appropriate amount of UVB irradiation can treat some skin diseases. At the same time, ultraviolet rays have the effect of sterilization and disinfection, so they are widely used in water purification, antiseptic and other fields. Ultraviolet light monitoring is of great significance in the fields of health protection, medical health, electrical equipment health management, environmental monitoring and pollutant analysis.

[0003] Traditional ultraviolet light monitoring devices usually include 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 signal outputs. They have the advantages of high test accuracy, high sensitivity, and fast response speed. However, photoelectric ultraviolet light monitoring devices are not flexible and have high production costs. Therefore, 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. The ultraviolet light dose can be determined based on the color change of the response element. They have the advantages of low cost, good flexibility, and good integration with the human body. However, 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 measurements.

[0004] In recent years, a method has emerged to combine the ultraviolet light responsive organic material azobenzene with a polymer piezoelectric material to prepare a flexible ultraviolet light monitoring device. The ultraviolet light monitoring device used in the above method has a low molecular weight. Although it has a certain flexibility, it has poor mechanical properties and cannot achieve dynamic service. In addition, the above ultraviolet light monitoring device can only output the intensity of ultraviolet light, and cannot achieve cumulative testing to obtain the ultraviolet light irradiation dose. Therefore, how to achieve the flexibility of ultraviolet light monitoring devices, dynamic service, and real-time monitoring of ultraviolet light intensity and irradiation dose is a technical problem that needs to be solved in this field. Summary of the invention

[0005] 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, so as to solve the defects in the prior art that the traditional ultraviolet light monitoring device is difficult to realize the good flexibility of the ultraviolet light monitoring device, the dynamic service and the real-time monitoring of the ultraviolet light intensity and the irradiation dose, and realize the good flexibility of the ultraviolet light monitoring device, the dynamic service and the real-time monitoring of the ultraviolet light intensity and the irradiation dose.

[0006] The invention provides a method for preparing a light-responsive thin film material, comprising the following steps.

[0007] placing 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol 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; The dihydroxy oligomer and the diisocyanate monomer are mixed, and the obtained mixture is prepolymerized in a nitrogen atmosphere at a temperature range of 60-100° C. for 2 hours to obtain a polymer; Adding the 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 electrospinning solution; The electrospinning liquid is used to perform electrostatic spinning to obtain the light-responsive film material.

[0008] According to a method for preparing a photoresponsive thin film material provided by the present invention, the dihydroxy oligomer includes one or more of polyethylene glycol, polytetrahydrofuran, and polycaprolactone diol, and the molecular weight of the dihydroxy oligomer is between 500g / mol and 3000g / mol.

[0009] According to a method for preparing a photoresponsive thin film material provided by the present invention, the diisocyanate-based monomer includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

[0010] According to a method for preparing a photoresponsive thin film material provided by the present invention, the molar ratio of the dihydroxy oligomer to the diisocyanate monomer is between 1:1.2 and 1:5.

[0011] According to a method for preparing a photoresponsive thin film material provided by the present invention, in the step of adding the 4,4'-dihydroxyhexyloxyazobenzene to the polymer, the sum of the molar number of the 4,4'-dihydroxyhexyloxyazobenzene and the molar number of the dihydroxy oligomer is equal to the molar number of the diisocyanate monomer.

[0012] According to a method for preparing a light-responsive thin film material provided by the present invention, 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.

[0013] According to a method for preparing a photoresponsive thin film material provided by the present invention, the photoresponsive thin film material is stored in an ion solution; the ion 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.

[0014] The present invention also provides a photoresponsive thin film material, which is prepared based on any of the above-mentioned methods for preparing the photoresponsive thin film material.

[0015] The present invention also provides an ultraviolet light monitoring device, comprising: 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 sequence from top to bottom; Wherein, the photoresponsive thin film material in the photoresponsive thin film material layer is prepared based on any of the above-mentioned methods for preparing the photoresponsive thin film material.

[0016] The present invention also provides an ultraviolet light monitoring system, comprising the ultraviolet light monitoring device, the electrometer, the voltage amplifier and the electronic device as described above; the electrometer, the voltage amplifier and the electronic device are electrically 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 for obtaining 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.

[0017] The invention provides a method for preparing a photoresponsive thin film material, a photoresponsive thin film material, an ultraviolet light monitoring device and a system, wherein 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol and a catalyst are placed under alkaline conditions and reacted within 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, the obtained mixture is prepolymerized within a temperature range of 60-100°C under a nitrogen atmosphere 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 a piezoelectric polymer are dissolved in a high boiling point solvent to obtain an electrospinning The electrospinning liquid is used for electrostatic spinning to obtain a light-responsive 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 an azobenzene group that responds to ultraviolet light can be obtained. Then, by combining the polyurethane with a piezoelectric polymer, a light-responsive film material with better flexibility, better mechanical properties and good ultraviolet light response can be prepared. The preparation process of the light-responsive film material is simple, no large-scale equipment is required during the preparation, and the preparation cost is relatively low. The material 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

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces 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 creative work.

[0019] Figure 1 It is a schematic flow chart of the method for preparing the light-responsive thin film material provided by the present invention.

[0020] Figure 2 It is a schematic diagram of the molecular structure of polyurethane containing azobenzene groups in the method for preparing the light-responsive thin film material provided by the present invention.

[0021] Figure 3 This is a scanning electron microscope photograph of the light-responsive thin film material provided by the present invention.

[0022] Figure 4 It is a schematic flow chart of the method for preparing the ultraviolet light monitoring device provided by the present invention.

[0023] Figure 5 It is a current change rate-time curve diagram of the ultraviolet light monitoring device provided by the present invention under the irradiation of ultraviolet light with different intensities.

[0024] Figure 6 It is one of the current change rate-time curves of the ultraviolet light monitoring device provided by the present invention under different stretching and bending lengths under ultraviolet light intensity irradiation.

[0025] Figure 7 This is the second current change rate-time curve diagram of the ultraviolet light monitoring device provided by the present invention under different stretching and bending lengths under ultraviolet light intensity irradiation.

[0026] Figure 8 It is a current change rate-time curve diagram of the ultraviolet light monitoring device provided by the present invention under the cyclic irradiation of ultraviolet light.

[0027] Fig. 9 This is a comparison chart of the responsiveness of ultraviolet light monitoring devices with different mass ratios of polyurethane containing azobenzene groups to piezoelectric polymer in Example 1 to ultraviolet light. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0030] In the description of the present application, the terms "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are usually a class, and the number of objects is not limited. For example, the first object can be one or more. In addition, in the description of the present application, "and / or" represents at least one of the connected objects, and the character " / " generally represents that the front and back associated objects are in an "or" relationship.

[0031] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "specific implementations", or "some specific implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0032] In the present invention, the instruments used, etc., without indicating the manufacturer, are all conventional products that can be purchased through regular channels. The methods described are conventional methods unless otherwise specified, and the raw materials described can be obtained from public commercial channels unless otherwise specified. If no specific technology or conditions are indicated in the examples, the technology or conditions described in the literature in the field or the product instructions are used.

[0033] Figure 1 FIG. 1 is a schematic diagram of a method for preparing a light-responsive thin film material provided by the present invention. Figure 1 As shown, the method comprises the following steps: step 101, placing 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol and a catalyst under alkaline conditions, reacting at a temperature range of 100-160° C. for 12-24 hours to obtain 4,4'-dihydroxyhexyloxyazobenzene; Step 102, mixing the dihydroxy oligomer and the diisocyanate monomer, and prepolymerizing the obtained mixture in a nitrogen atmosphere at a temperature range of 60-100° C. for 2 hours to obtain a polymer; Step 103, adding 4,4'-dihydroxyhexyloxyazobenzene to the polymer to obtain a polyurethane containing an azobenzene group; Step 104, 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.; Step 105: Perform electrospinning using the electrospinning solution to obtain a light-responsive thin film material.

[0034] It should be noted that the polyurethane containing azobenzene groups (Az-TPU) in the examples of the present invention was synthesized independently in the laboratory. Figure 2 Schematic diagram of the molecular structure of polyurethane containing azobenzene group in the method for preparing the light-responsive thin film material provided by the present invention. Figure 2 shown.

[0035] In step 102, since the polymerization reaction speed is slow when the temperature is too low, it is difficult for the dihydroxy oligomer and the diisocyanate monomer to polymerize, while the high boiling point solution is easy to volatilize when the temperature is too high, and the system is easy to cross-link when the chain extender is added. Therefore, the reaction temperature of the dihydroxy oligomer and the diisocyanate monomer is selected to be between 60°C and 100°C.

[0036] In step 102, the mixture of dihydroxy oligomer and diisocyanate monomer can complete polymerization reaction in a nitrogen atmosphere at a temperature range of 60-100° C. for 2 hours.

[0037] In step 103, since the length of the spacer is too short, the conjugation effect of the benzene ring has a great influence on the hydroxyl group, and the polymerization reaction is difficult to proceed; if the length of the spacer is too long, the azobenzene group is affected more during the tension process, which has a great impact on the dynamic response signal. Therefore, in the embodiment of the present invention, 4,4'-dihydroxyhexyloxyazobenzene containing a six-carbon spacer is added to the polymer as a chain extender.

[0038] In step 105, the hydrogen bonding and microphase separation of polyurethane can provide excellent mechanical properties for the photoresponsive film material. During the stretching and bending process of the photoresponsive film material, the soft segment of the polyurethane undergoes a large deformation, and the deformation of the photoresponsive element 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 photoresponsive film material, and the above device can complete dynamic testing.

[0039] Optionally, in step 104, the mass ratio of polyurethane to piezoelectric polymer is 1:0.4-1:5.

[0040] Preferably, in step 104, the mass ratio of polyurethane to piezoelectric polymer is 1:2.

[0041] Optionally, the film substrate subjected to electrospinning in step 105 is a fiber film substrate, and the fiber film substrate is prepared by a spinning method, wherein the spinning method is selected from one of wet spinning, dry spinning, electrospinning and microfluid spinning.

[0042] Preferably, the DC voltage used in the electrospinning process in step 105 is 8-15KV, and the electrospinning liquid in the syringe is pushed at a speed of 0.5-1mL / h. Continuously spinning preferably 1-2mL of the electrospinning liquid to obtain a light-responsive film material of a desired thickness; the receiving device is a cylindrical drum, and the receiving speed is preferably 500r / min-2800r / min.

[0043] Optionally, the catalyst in step 101 may be potassium iodide.

[0044] Optionally, the piezoelectric polymer in step 101 may include one or more of polyvinylidene difluoride (PVDF), polyacrylonitrile (PAN) and polydimethylsiloxane (PDMS).

[0045] 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.

[0046] It should be noted that in the embodiments 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 to the polymer and improve the elongation at break of the polymer. At the same time, when the prepared light-responsive film material is stretched, the soft segment can replace the hard segment and the light-responsive group to stretch, thereby reducing the effect of the light-responsive film material being stretched on ultraviolet light monitoring.

[0047] As an optional embodiment, the diisocyanate-based monomer includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

[0048] 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.

[0049] As an optional embodiment, the molar ratio of the dihydroxy oligomer to the diisocyanate monomer is between 1:1.2 and 1:5.

[0050] 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 moles of the dihydroxy oligomer is equal to the mole of the diisocyanate monomer.

[0051] 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.

[0052] 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.

[0053] In the embodiment of the present invention, 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol 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 obtained 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 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 an azobenzene group that responds to ultraviolet light. Then, by combining the polyurethane with a piezoelectric polymer, a photoresponsive film material with better flexibility, better mechanical properties and good ultraviolet light response can be prepared. The preparation process of the photoresponsive 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 are flexible, can be dynamically used, and can monitor ultraviolet light irradiation dose in real time.

[0054] 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.

[0055] 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 sequence from top to bottom; 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.

[0056] The present invention prepares a stretchable and foldable light-responsive film material by blending an azobenzene-containing, ultraviolet-light-responsive, high-molecular-weight polyurethane with a piezoelectric polymer, and then immerses the light-responsive film material in an ion solution, and then packages it with a copper wire, a graphite-based acrylate tape and a polyacrylate tape to prepare an ultraviolet light monitoring device.

[0057] During the ultraviolet light irradiation process of the above-mentioned ultraviolet light monitoring device, due to the photoinduced contraction effect of the azobenzene group, the azobenzene group in the light-responsive thin film material layer in the above-mentioned ultraviolet light monitoring device will produce cis-trans isomerism and volume change under ultraviolet light, driving the molecular chain to shrink and produce photoinduced stress, causing the piezoelectric polymer in the light-responsive thin film material layer to generate a voltage signal, thereby converting the ultraviolet light signal into a voltage signal to realize ultraviolet light intensity detection.

[0058] In some preferred embodiments, in the characterization of ultraviolet light detection capability, azobenzene produces cis-trans isomerization and volume changes under ultraviolet light, which drives the molecular chain to shrink and produce photoinduced stress, causing the piezoelectric material to generate voltage. The change in ultraviolet light intensity can be monitored by detecting the current or voltage change.

[0059] On the other hand, by utilizing the excellent flexibility and mechanical properties of the above-mentioned polyurethane, the above-mentioned ultraviolet light monitoring device can achieve dynamic service. By utilizing the photocontraction effect of the azobenzene group, the above-mentioned ultraviolet light monitoring device can generate a stable light response signal, and then realize the cumulative monitoring of ultraviolet light, thereby realizing the monitoring of ultraviolet light irradiation dose.

[0060] The ultraviolet light monitoring device in the embodiment of the present invention is prepared based on the above-mentioned photoresponsive thin film material. It can utilize the good flexibility, mechanical properties and ultraviolet light response performance of the above-mentioned photoresponsive thin film material to achieve the ultraviolet light monitoring device with good flexibility, dynamic service and real-time monitoring of ultraviolet light intensity and irradiation dose, and has broad application prospects.

[0061] In order to facilitate the understanding of the method for preparing the photoresponsive thin film material, the ultraviolet monitoring device and the ultraviolet monitoring system provided by the present invention, the method for preparing the photoresponsive thin film material, the ultraviolet monitoring device and the ultraviolet monitoring system provided by the present invention are specifically described below through multiple embodiments.

[0062] Example 1

[0063] 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol and a catalyst are placed under alkaline conditions and reacted at a temperature range of 100-160° C. for 12-24 hours to obtain 4,4'-dihydroxyhexyloxyazobenzene.

[0064] The dihydroxy oligomer and the diisocyanate monomer are mixed, 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.

[0065] By adding 4,4'-dihydroxyhexyloxyazobenzene into the polymer, a polyurethane containing azobenzene groups is obtained.

[0066] A certain amount of 4,4'-dihydroxyhexyloxyazobenzene and piezoelectric polymer are mixed and dissolved in a high boiling point solvent, stirred at 40-60°C for 4-12 hours using a magnetic stirrer to fully mix and dissolve, and then a flexible light-responsive thin film material is prepared by a spinning method.

[0067] Optionally, the high boiling point solvent is any one or more of dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF) and N-methylpyrrolidone (NMP).

[0068] Preferably, the high boiling point solvent is N,N-dimethylformamide.

[0069] Figure 3 is a scanning electron microscope photo of the photoresponsive thin film material provided by the present invention. The surface morphology of the photoresponsive thin film material provided by the present invention is as follows Figure 3 shown.

[0070] Example 2

[0071] Figure 4 FIG. 1 is a schematic diagram of a method for preparing an ultraviolet light monitoring device provided by the present invention. Figure 4 As shown, the preparation method of the ultraviolet monitoring device includes: using an analytical balance to weigh 600 mg of polyurethane powder containing azobenzene groups and 400 mg of piezoelectric polymer powder, respectively, and pouring them into a glass bottle. Using a syringe to take 5 ml of N,N-dimethylformamide, respectively, and adding it to the glass bottle for dissolution, to obtain an electrochemical solution.

[0072] Electrospinning liquid was used for electrospinning. The DC voltage used in the electrospinning process was 15KV, and the solution propulsion speed in the syringe was 1mL / h to obtain a photoresponsive film material of the desired thickness. The receiving device was a stainless steel cylindrical drum with a layer of aluminum foil on the surface, and the receiving speed was controlled by a servo motor at 2800r / min.

[0073] After spinning, tear off the photoresponsive film material with tweezers and dry it overnight at room temperature and pressure. Finally, cut the photoresponsive film material into 30 mm × 15 mm strips for later use, with the long side being the orientation direction.

[0074] Take 10 ml of 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate ionic liquid and put it in a glass bottle. Put the cut photoresponsive film material into the glass bottle and completely immerse it in the ionic liquid. Soak it for 12 hours. Take it out with tweezers and use two pieces of filter paper to absorb the ionic liquid on the surface of the photoresponsive film material. Dry it in a vacuum oven at 40°C for 2 hours.

[0075] After drying the ionic liquid on the surface of the photoresponsive film material, flatten the photoresponsive film material on the filter paper. Cut a 1mm×30mm copper wire and paste it along the short side at one end of the device. Then adhere a layer of conductive double-sided tape as a conductive layer, cut off the excess part with scissors, and then adhere polyacrylate tape as a packaging layer, and cut off the excess part. Then turn the photoresponsive film material over and perform the same operation on the other side to obtain a packaged ultraviolet light monitoring device.

[0076] When the ultraviolet light monitoring device is irradiated with ultraviolet light, an electrometer is used to obtain a light response signal generated by the ultraviolet light monitoring device, and a voltage amplifier and electronic equipment are used to obtain the ultraviolet light intensity and / or ultraviolet light irradiation dose corresponding to the above light response signal. The ultraviolet light intensity and / or ultraviolet light irradiation dose can then be sent to a user terminal via Bluetooth for the user to view.

[0077] Example 3

[0078] This embodiment includes a photoresponsivity test method and test results of an ultraviolet light monitoring device, including a photo-induced stress test, a static photoresponsivity test, a dynamic photoresponsivity test, and an ultraviolet light irradiation dose test.

[0079] 1) Static photoresponse test

[0080] The UV light intensity detection and analysis system consists of an electrometer (6517B), a UV light source (365nm), a computer and other equipment. The specific operation is: connect the UV light monitoring device to the circuit, and under the irradiation of different UV light intensities, the electrometer (6517B) detects the current change of the light response signal emitted by the real-time UV light monitoring device, and completes the recording of time, current and UV light intensity data.

[0081] Figure 5 : is a current change rate-time curve diagram of the ultraviolet light monitoring device provided by the present invention under the irradiation of ultraviolet light with different intensities. The current change rate-time curve diagram of the ultraviolet light monitoring device in this embodiment under the irradiation of ultraviolet light with different intensities is as follows Figure 5 shown.

[0082] The UV light intensity range that can be detected by the UV monitoring device is 0.05~50mW·cm -2 The rise time (the time when the current change rate reaches the peak value) is 0.1 second. The ultraviolet light monitoring device provided by the present invention has a wide detectable wavelength range, a fast response speed, and a good linear relationship within the response range. When the ultraviolet light is continuously irradiated, the response signal is a smooth straight line, which can meet the needs of real-time monitoring of ultraviolet intensity and dosage in sunlight.

[0083] 2) Dynamic photoresponsiveness test

[0084] The UV light intensity detection and analysis system consists of an electrometer (6517B), a UV light source (365nm), a computer and other equipment. A stepper motor is used to control the UV light monitoring device to stretch or bend under clamping conditions. The UV light responsiveness of the UV light monitoring device is tested under dynamic conditions of stretching and bending.

[0085] Figure 6 It is one of the current change rate-time curves of the ultraviolet light monitoring device provided by the present invention under different stretching and bending lengths under ultraviolet light intensity irradiation. Figure 7 This is the second current change rate-time curve of the ultraviolet monitoring device provided by the present invention under different stretching and bending lengths under ultraviolet light intensity. 2 The current change rate-time curves at different stretching and bending lengths under UV light intensity are shown in the figure below. Figure 6 and Figure 7 shown.

[0086] The stretched length refers to the percentage of the difference between the length before and after stretching as a percentage of the original length. The bending curvature refers to the curvature of the UV monitoring device with a finger distance of 2cm after bending. In the figure, UV refers to ultraviolet light, and UV+10% or UV+30% refers to 30mW / cm 2 Under high-intensity ultraviolet light irradiation (UV light on for 1s – off for 1s), the device is stretched to 110% or 130% of its original length at a frequency of 0.5Hz, generating a current signal.

[0087] like Figure 6 and Figure 7 As shown, when the stretch length is less than 30% and the bending curvature is 1.4cm -1 When the conditions are as follows, the ultraviolet light monitoring device provided by the present invention is less affected by the stretching and bending signals and can be ignored.

[0088] 3) UV dose test

[0089] Connect the UV monitoring device to the circuit and use 10mW / cm 2 、7.5mW / cm 2 , 4mW / cm 2 , 1mW / cm 2 , 0mW / cm 2 The device is irradiated with light intensity, each light intensity lasts for 5 seconds, and repeated 400 cycles. The electrometer (6517B) detects the real-time current changes and completes the recording of time, current, ultraviolet light intensity and other data.

[0090] Figure 8The current change rate-time curve of the ultraviolet light monitoring device provided by the present invention under the cycle irradiation of ultraviolet light. The current change rate-time curve of the ultraviolet light monitoring device provided by the present invention under the cycle irradiation of ultraviolet light of 400 cycles is as follows Figure 8 shown.

[0091] By integrating the curve with origin and according to the linear relationship between UV intensity and current calibrated in the static light responsiveness test, the theoretical UV dose tested by the UV monitoring device can be calculated to be 402.27 kJ / m 2 The actual irradiation dose is 405 kJ / m 2 , the error is less than 1%.

[0092] Comparative Example 1

[0093] The mass ratio of polyurethane containing azobenzene groups to piezoelectric polymer was adjusted, and three groups of UV monitoring devices with different ratios were prepared using the same process. The UV light responsiveness of each group of UV monitoring devices was tested.

[0094] Fig. 9 This is a comparison chart of the responsiveness of ultraviolet light monitoring devices with different mass ratios of polyurethane containing azobenzene groups to piezoelectric polymer in Example 1. Fig. 9 As shown in the figure, the UV light monitoring device with a mass ratio of 1:2 between polyurethane containing azobenzene groups and piezoelectric polymer has the highest responsiveness and the best linear correlation, with a responsivity of 0.93 nA / mW·cm -2 , R 2 =0.998.

[0095] Based on the contents of the above embodiments, a UV monitoring system includes: the above UV monitoring device, an electrometer, a voltage amplifier and an electronic device; 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.

[0096] Optionally, the electronic device in the embodiment of the present invention may be a microcontroller, preferably an Arduino microcontroller.

[0097] Optionally, the ultraviolet light monitoring system in the embodiment of the present invention may further include a display device.

[0098] Optionally, the ultraviolet light monitoring system in the embodiment of the present invention may further include a power supply, and the power supply may be used to power the voltage amplifier and the electronic equipment.

[0099] When the ultraviolet light monitoring system performs ultraviolet light monitoring, the light response signal generated by the ultraviolet light monitoring device is amplified by a voltage amplifier, and then the amplified light response signal is input into an Arduino microcontroller, and the amplified light response signal is converted into a corresponding ultraviolet light intensity and / or ultraviolet light irradiation dose through computer programming.

[0100] The ultraviolet light monitoring system can also send the obtained ultraviolet light intensity and / or ultraviolet light irradiation dosage to the user terminal via Bluetooth for the user to view.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a photoresponsive thin film material, characterized in that: include: placing 4,4'-dihydroxyazobenzene, 6-bromo-n-hexanol 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; The dihydroxy oligomer and the diisocyanate monomer are mixed, and the obtained mixture is prepolymerized in a nitrogen atmosphere at a temperature range of 60-100° C. for 2 hours to obtain a polymer; Adding the 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 electrospinning solution, wherein the boiling point of the high boiling point solvent is not less than 120° C.; The electrospinning liquid is used to perform electrostatic spinning to obtain the light-responsive film material.

2. The method for preparing a photoresponsive thin film material according to claim 1, characterized in that: 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 photoresponsive thin film material according to claim 1, characterized in that: The diisocyanate monomer includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

4. The method for preparing a photoresponsive thin film material according to claim 1, characterized in that: 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, characterized in that: 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 photoresponsive thin film material according to claim 1, characterized in that: 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 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; Wherein, 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 as claimed in 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 for obtaining 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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