A force-responsive luminescent material and its application in the field of detection

Abstract

The present invention discloses a force-responsive luminescent material and its application in the field of detection. The material contains a compound with the following structural formula: The initial powder of the material in the solution of the present invention only emits weak light, but when a force is applied to it (such as mechanical forces like scratching, shearing, etc.), it emits bright cyan light under ultraviolet light. After being fumed with a solvent, it returns to the initial emission state, has good reversibility, can be used repeatedly, and has good application prospects in the fields of detection and the like.

Description

Technical Field

[0001] The present invention relates to the technical field related to luminescent materials, and in particular to a force-induced responsive luminescent material and its application in the detection field. Background Art

[0002] Cracks and damage may occur on the surface or inside of goods, fabrics or films, such as packaging boxes, cargo stacking areas, and the use environment of fabric products or films during transportation. These scratches and damages may cause the quality of goods to decline, the functional performance to be damaged, and even make the goods unable to be used normally or cause safety hazards. For example, during transportation, the outer packaging of goods may be hit or scratched, causing damage or rupture of the internal goods, resulting in significant property losses, especially precision devices such as computer hosts, LCD screens and porcelain. Similarly, during the use of fabric products or films, if invisible scratches or damage occur, it may lead to quality degradation, shortened life, and even cause safety problems, such as fabric products or films rupture or loosening causing personal injury; for example, during the stretching process of fabrics, yield deformation or fracture may occur, which may cause the elastic recovery performance of the fabric to decline, causing it to lose its original elasticity and tightness. This damage may affect the appearance, comfort and performance of the fabric, and even make it unusable. Therefore, timely detection and treatment of these scratches and damages are of great significance to protecting property and personal safety.

[0003] Force-induced responsive materials refer to materials that can produce observable responses or changes when subjected to external forces or stresses. These materials show specific changes in physical (such as optical), chemical or electrical properties under mechanical stress and can be used to achieve various functions and applications. Among them, force-induced responsive luminescent materials are easier to be discovered or detected because they can show changes or responses in optical properties when subjected to force. Therefore, they have good application prospects in the field of detection. However, to date, there is no unified theory on the formation mechanism of force-induced responsive luminescent materials, and the number of types is relatively small compared to mechanochromic materials, which limits the practical application of this type of material. Therefore, it is of great significance to prepare new force-induced responsive luminescent materials. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a mechano-responsive luminescent material, which can undergo mechanochromic change and mechanofluorescence enhancement under mechanical action.

[0005] According to one aspect of the present invention, a mechanoresponsive luminescent material is provided, comprising a compound of the following structural formula:

[0006]

[0007] According to a preferred embodiment of the present invention, it has at least the following beneficial effects: Compounds that usually have aggregation-induced fluorescence (AIE) properties exhibit strong photoluminescence (PL) in the aggregated or solid state. However, the initial powder of the material of the present invention's solution only emits weak light. But when a force is applied to it (such as mechanical forces like scratching, shearing, etc.), it emits bright cyan light under ultraviolet light. After solvent fuming, it returns to the initial emission state, has good reversibility, can be reused, and has good application prospects in fields such as detection. The above-structured compound can be prepared into a force-responsive luminescent material with high molecular materials such as polyvinyl alcohol and polyethylene glycol, and thus can be applied to fields such as detection.

[0008] According to another aspect of the present invention, there is provided an application of a compound in the preparation of a force-responsive luminescent material, and the structural formula of the compound is as follows:

[0009]

[0010] According to still another aspect of the present invention, there is provided an application of the above force-responsive luminescent material in the field of detection.

[0011] In some embodiments of the present invention, the detection includes product defect detection and quality detection.

[0012] In some preferred embodiments of the present invention, the product includes at least one of goods, films or fabrics.

[0013] During transportation, goods may collide and scratch each other for various reasons. Sometimes such scratches are difficult to detect by the naked eye. If not discovered in time, it will cause property losses, especially for precision devices such as computer hosts, liquid crystal displays and porcelain. If the initial powder of the above force-responsive luminescent material is applied to the packaging box and two packaging boxes are scratched, bright cyan fluorescence emission can be observed in the scratched area under a 365 nm ultraviolet lamp, which is convenient for detecting damage.

[0014] The detection of film cracks also plays a crucial role in life. A micro-nano fiber membrane can be prepared by electrospinning technology. This micro-nano fiber membrane can completely retain all the characteristics of the initial powder and hardly emits light under a 365 nm ultraviolet lamp. When scratched with a sharp object on the micro-nano fiber membrane, obvious scratched marks can be observed on the micro-nano fiber membrane under ultraviolet light.

[0015] In addition, it can also be used to observe the yield deformation and fracture during the stretching process of fabrics. Through the above force-responsive light, the deformation and fracture accompanied during the stretching process of fabrics can be characterized. This can not only be used to determine whether there are defects in fabrics, but also be used to determine the quality of fabrics, providing a good basis for subsequent practical applications.

[0016] A method for detecting product defects or quality grades, comprising the following steps: applying the above-mentioned force-induced responsive luminescent material to the product to be detected and / or the packaging material of the product to be detected, irradiating the force-induced responsive luminescent material with an ultraviolet light source as an excitation source, and observing the fluorescence intensity to determine whether there are defects or determine the quality grade; wherein, the application includes applying to the surface and / or the interior.

[0017] Applying it to the surface or interior of the product to be tested is sufficient, without the need for complex operations such as photoinitiated polymerization. The detection method of the present invention's solution is simple to operate, has high detection efficiency, can achieve batch full-automatic detection, and has good industrial application prospects.

[0018] For some important goods, it can be directly applied to the packaging surface to better avoid damage.

[0019] In some preferred embodiments of the present invention, the application includes at least one of coating, impregnation, and electrospinning. By operations such as coating, impregnation, or electrospinning, the force-induced responsive luminescent material is applied to the surface of the product to be tested, and the operation is simple.

[0020] In some preferred embodiments of the present invention, the wavelength of the ultraviolet light source is 320 nm to 405 nm; preferably 345 nm to 385 nm; more preferably 365 nm.

[0021] In some preferred embodiments of the present invention, the detection method further includes fumigating the product to be detected and / or the packaging material of the product to be detected to restore the force-induced responsive luminescent material to its initial emission state. Utilizing the reversibility of the force-induced light response of the material of the present invention's solution, after fumigation, it is restored to its initial emission state, thereby realizing repeated use and achieving the effect of fluorescence switch switching. Especially for packaging materials, having this property can greatly improve economic benefits.

[0022] In some preferred embodiments of the present invention, the solvent used for fumigation is at least one of ethanol, dichloromethane, tetrahydrofuran, chloroform, or acetone. Any volatile solvent can be used.

[0023] In some embodiments of the present invention, the defects include damage, cracks, slips, or deformations, etc.

[0024] In some embodiments of the present invention, the defects refer to defects caused by mechanics; such as mechanical external forces like scratches and collisions.

[0025] In some embodiments of the present invention, the observation includes at least one of naked-eye observation and detection device observation; preferably, the detection device includes at least one of a spectrometer and a CCD camera system. The degree of damage and cracks can be qualitatively or semi-quantitatively detected and analyzed by naked-eye observation, and can also be fully quantitatively detected and analyzed by a spectrometer.

[0026] According to another aspect of the present invention, a stress detection method is provided, including the following steps: applying the above-mentioned force-induced response luminescent material to the product to be detected, realizing the force-induced response by applying mechanical force to the product to be detected, and irradiating the force-induced response luminescent material with an ultraviolet light source as the excitation source, and observing the change in fluorescence intensity to detect the stress change; wherein, the application includes applying to the surface and / or inside of the product to be detected; preferably, the application includes applying by at least one of coating, impregnation, and electrospinning.

[0027] According to another aspect of the present invention, the above-mentioned force-induced response luminescent material is proposed to be used in the preparation of toys, shape memory materials, impact-resistant protection materials, force sensor materials, and mechanical probe materials.

[0028] A material contains the above-mentioned force-induced response luminescent material; wherein, the material can be used to prepare at least one of the following products:

[0029] 1) Toys;

[0030] 2) Shape memory materials;

[0031] 3) Impact-resistant protection materials;

[0032] 4) Force sensor materials;

[0033] 5) Mechanical probe materials;

[0034] 6) Optical switch materials;

[0035] 7) Anti-counterfeiting materials;

[0036] 8) Flexible electronic products;

[0037] 9) Intelligent packaging materials.

[0038] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0040] Figure 1It is the application effect diagram in Application Example 1 of the present invention; a) Molecular structure of TPE-HXD, b) Corresponding fluorescence spectrum changes, c) Fluorescence images under different treatments;

[0041] Figure 2 It is the application effect diagram in Application Example 2 of the present invention;

[0042] Figure 3 It is the application effect diagram in Application Example 3 of the present invention;

[0043] Figure 4 It is the application effect diagram in Application Example 4 of the present invention; a) Fluorescence images under different strains; b) Stress-strain curve.

[0044] Figure 5 It is the effect diagram of fluorescence change by feedback of fluorescence image gray value through matlab in Application Example 4 of the present invention. Specific embodiments

[0045] The concept of the present invention and the technical effects produced will be clearly and completely described below in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention. The test methods used in the embodiments are all conventional methods unless otherwise specified; the materials, reagents, etc. used, unless otherwise specified, are all reagents and materials that can be obtained from commercial channels. Unless otherwise specified, the same parameter values are taken in each embodiment. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention.

[0046] In the description of the present invention, room temperature refers to 25 ± 5°C, specifically 25°C.

[0047] Embodiment

[0048] In this example, a force-responsive luminescent material was prepared. The specific process is as follows:

[0049] (1) Synthesis of intermediate tetraphenylethylene aldehyde:

[0050] Under N2 atmosphere, triphenylbromoethylene (3.35 g, 10 mmol) and 4-formylphenylboronic acid (3.00 g, 20 mmol) were added to a three-necked flask, then 50 mL of tetrahydrofuran (THF), 18 mL of 2 mol / L aqueous potassium carbonate solution, and tetrabutylammonium bromide (TBAB) (0.32 g, 1.0 mmol) were added. After stirring at room temperature and passing N2 for half an hour, Pd(PPh3)4 (0.010 g, 8.7×10 - 3(mmol), heated to 90 °C and reacted for 24 h. Then the reaction solution was poured into water, extracted three times with ethyl acetate, the organic layer was dried over anhydrous sodium sulfate, the solvent was removed by rotary evaporation under reduced pressure, and purified by silica gel column chromatography. The eluent was a mixed solvent of dichloromethane and n-hexane with a volume ratio of 1:2. 3.25 g of the product was obtained with a yield of 97%.

[0051]

[0052] (2) Synthesis of the target product

[0053] Synthesis of 9-(4-(1,2,2-triphenylethenyl)phenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione:

[0054] TPEA (0.361 g, 1 mmol) was added to 30 mL of anhydrous ethanol and heated with stirring. After TPEA was completely dissolved, anhydrous magnesium chloride (0.019 g, 0.2 mmol) and acetic acid (9 mL, 30% of ethanol) as the catalyst were added, and stirring was continued at 90 °C for 10 min. Urea (0.09 g, 1.5 mmol) and 1,3-cyclohexanedione (0.294 g, 3 mmol) were added to the three-necked flask. After reacting for 24 h, filtration was carried out, and the filter residue was washed repeatedly with ethanol 3 times to obtain a white powder (0.44 g, 80%, abbreviated as TPE-HXD).

[0055]

[0056] It was confirmed by NMR and mass spectrometry that the force-responsive luminescent material prepared by the embodiment of the present invention was consistent with the theoretical structure.

[0057] Application Example 1

[0058] In this application example, the force-responsive luminescent material prepared in the example was applied to stress detection. This material has good application prospects in stress detection.

[0059] Specifically, generally speaking, AIE compounds often show strong PL (Photoluminescence) in the aggregated state or solid state. However, the initial powder of the TPE-HXD compound (structural formula as Figure 1 shown in a)) obtained by the embodiment of the present invention emitted weak fluorescence, and the fluorescence quantum efficiency was only 4.37%. Surprisingly, when the initial powder was scratched, under a 365 nm ultraviolet lamp, it emitted bright cyan light, and the fluorescence quantum efficiency was 30.08%. Figure 1 b) is its corresponding fluorescence spectrum diagram. It can be seen from the figure that the emission spectrum of the ground powder is significantly red-shifted and the fluorescence intensity is enhanced. According to the change of the fluorescence intensity, the stress magnitude can be analyzed.

[0060] Furthermore, after fumigation with dichloromethane vapor, it can return to the initial emission state, showing good reversibility. As Figure 1 shown in c), the entire fluorescence change process can be distinguished with the naked eye.

[0061] Application Example 2

[0062] This application example applies the force-responsive luminescent material prepared in the example to the defect detection during the transportation of goods.

[0063] During the transportation of goods, collisions and scratches may occur due to various reasons. Sometimes such scratches are difficult to detect with the naked eye. If not discovered in time, it will cause property losses, especially for precision devices such as computer hosts, liquid crystal displays, and porcelain. Therefore, the initial powder of TPE-HXD was applied to the packaging box, and two packaging boxes were scratched. It can be observed under a 365 nm ultraviolet lamp that there is bright cyan fluorescence emission in the scratched area (as Figure 2 shown), which is convenient for detecting damage.

[0064] Application Example 3

[0065] This application example applies the force-responsive luminescent material prepared in the example to the detection of film defects.

[0066] The detection of film cracks also plays a crucial role in life. Therefore, the force-responsive luminescent material prepared in the above example was added to the electrospinning solution, and a micro-nano fiber membrane was prepared through electrospinning technology. This membrane completely retains all the characteristics of the initial powder and hardly emits light under a 365 nm ultraviolet lamp. When the film is scratched, a bright scratch mark with a width of 30 μm can be clearly observed on the film under the ultraviolet lamp (as Figure 3 shown). Therefore, through this method, the detection of film defects, especially defects caused by mechanics, can be achieved.

[0067] Application Example 4

[0068] This application example applies the force-responsive luminescent material prepared in the example to the detection of fabric defects or quality.

[0069] During the stretching process of fabrics, yield deformation and fracture often occur. Traditional detection methods only obtain a set of stretching data in the end. However, during the stretching process, it is difficult to accurately determine the positions where deformation and fracture occur, so it is difficult to monitor the specific whole process.

[0070] In view of this, by uniformly dispersing the force-responsive luminescent material powder prepared in the embodiment of the present invention in water, and immersing rattan twill fabric in it, and then drying it in a vacuum oven, a rattan twill fabric for stretching was prepared (as Figure 4 and5 As shown). Before stretching, the prepared rattan twill fabric had weak fluorescence emission and almost no luminescence. When stretched by 20%, two bright cyan fluorescence emissions began to appear. As the stretching continued, when the stretching reached 80%, a large area of cyan fluorescence emission appeared in the entire area of the fabric, indicating that the fabric was accompanied by deformation and fracture during the stretching process. Subsequently, the fluorescence images at different strains were converted into gray values and mapped with blue-red using Matlab software, which can further characterize the damage situation during the fabric stretching process (as Figure 5 shown). This result shows that the material of the solution of the present invention has good prospects in the subsequent practical application fields such as product defect and quality grade identification.

[0071] The above has described the embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention.

Claims

1. A force-responsive luminescent material, characterized in that, Compounds containing the following structural formula: 。 2. Use of a compound in the preparation of a force-responsive luminescent material, characterized in that, The structural formula of the said compound is as follows: 。 3. Use of the force-responsive luminescent material according to claim 1 in the field of detection.

4. The application according to claim 3, characterized in that, The said detection includes product defect detection and quality detection.

5. The application according to claim 4, characterized in that, The said products include at least one of goods, films or fabrics.

6. A method for detecting product defects or quality grades, characterized in that, It includes the following steps: applying the force-responsive luminescent material according to claim 1 to the product to be detected and / or the packaging material of the product to be detected, irradiating the force-responsive luminescent material with an ultraviolet light source as the excitation source, and observing the fluorescence intensity to determine whether there are defects or determine the quality grade; wherein, the said application includes applying to the surface and / or inside.

7. The product defect or quality grade detection method according to claim 6, characterized in that The said application includes at least one of coating, impregnation, electrospinning.

8. The detection method according to claim 7, wherein The said detection method further includes fumigating the product to be detected and / or the packaging material of the product to be detected to make the force-responsive luminescent material return to the initial emission state.

9. The detection method according to claim 8, wherein The solvent used for the said fumigation is at least one of ethanol, dichloromethane, tetrahydrofuran, chloroform or acetone.

10. The detection method according to claim 7, characterized in that, The said defects include damage, cracks, slips or deformations.

11. The detection method according to claim 7, characterized in that The said defects refer to defects caused by mechanics.

12. The detection method according to claim 11, wherein, The said mechanics is mechanical force.

13. The detection method according to claim 12, wherein, The said defects include defects caused by scratching and collision.

14. The detection method according to claim 7, wherein The said observation includes at least one of naked-eye observation and observation by a detection device.

15. The detection method according to claim 14, wherein The said detection device includes at least one of a spectrometer or a CCD imaging system.

16. A stress detection method, characterized in that, It includes the following steps: applying the force-responsive luminescent material according to claim 1 to the product to be detected, realizing force response by applying mechanical force to the product to be detected and irradiating the force-responsive luminescent material with an ultraviolet light source as the excitation source, and observing the change in fluorescence intensity to detect stress change; wherein, the said application includes applying to the surface and / or inside of the product to be detected.

17. The stress detection method according to claim 16, wherein The said application includes applying by at least one of coating, impregnation, electrospinning.

18. Use of the force-responsive luminescent material according to claim 1 in the preparation of toys, shape memory materials, impact-resistant protective materials, force sensor materials, mechanical probe materials.

19. A material, characterized in that, Containing the force-responsive luminescent material according to claim 1; wherein, the said material can be used to prepare at least one of the following products: 1) Toys; 2) Shape memory materials; 3) Impact-resistant protective materials; 4) Force sensor materials; 5) Mechanical probe materials; 6) Optical switch materials; 7) Anti-counterfeiting materials; 8) Flexible electronic products; 9) Smart packaging materials.

Images