A stress distribution time-lapse imaging film and a preparation method and application thereof

Abstract

The present application relates to stress luminescence elastic film and stress distribution time-lapse imaging detection technical field, specifically relates to a kind of stress distribution time-lapse imaging film and its preparation method and application.The specific preparation method includes: Sr source, silicon dioxide, Eu source and Dy source are mixed using wet grinding, after drying, sintering is carried out at 1200 ℃-1300 ℃, then grinding is carried out, and mixed powder is obtained;Mixed powder and precursor mixture of elastic matrix are mixed, then heated and solidified, and stress distribution time-lapse imaging film is obtained.The present application mainly uses high-temperature solid-phase method to synthesize a special mixed powder, the mixed powder is co-doped with Eu 2+ And Dy 3+ And multiple elements, not only give the prepared stress distribution time-lapse imaging film the characteristics of thermoluminescence, but also significantly enhance its stress luminescence intensity, effectively solve the problem of low stress luminescence intensity of existing stress luminescence elastic film in time-lapse stress display.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stress luminescence elastic film and stress distribution time-lapse imaging detection, and in particular relates to a stress distribution time-lapse imaging film and a preparation method and application thereof. BACKGROUND

[0002] As a new type of functional material, stress luminescence elastic film has attracted much attention due to its high sensitivity to external stress stimulation, visual luminescence, good stability and repeatability, and good compatibility with the surface of engineering structures. Stress luminescence elastic film can produce different stress luminescence phenomena of different colors and intensities when subjected to different forms and intensities of stress stimulation, which is also a key factor for stress luminescence elastic film to be applied to various stress distribution detection scenarios. However, most of the stress luminescence elastic films currently produce instantaneous luminescence when subjected to stress stimulation, which means that the luminescence phenomenon lasts for a very short time after the film is subjected to stress stimulation, and it is often difficult to be effectively captured and recorded, which limits the application of stress luminescence elastic film in some special scenarios such as detection of stress damage in closed engineering structures, increases the detection difficulty, and improves the complexity and uncertainty of detection.

[0003] The existing technical solution of stress luminescence time-lapse imaging mainly involves the development and preparation of stress luminescence materials, and the core of the solution is to develop stress luminescence materials with time-lapse luminescence characteristics, so that the film can continue to luminesce for a period of time after being subjected to stress stimulation, thereby allowing longer observation and recording.

[0004] Currently, it has been proposed that lithium niobate material doped with Pr 3+ is a very potential stress luminescence material with time-lapse luminescence characteristics, however, the preparation process of this material is complex, and the intensity of the time-lapse stress luminescence produced under stress stimulation is low and difficult to detect, especially difficult to be effectively captured by the naked eye or conventional detection equipment, which limits its performance in practical applications. SUMMARY

[0005] In order to solve the problem of low stress luminescence intensity of the existing stress luminescence elastic film in time-lapse stress display, the purpose of the present application is to provide a stress distribution time-lapse imaging film and a preparation method and application thereof.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is as follows.

[0007] The present application provides a preparation method of a stress distribution time-lapse imaging film, comprising the following steps:

[0008] The Sr source, silicon dioxide, Eu source and Dy source are mixed by wet grinding, dried, sintered at 1200-1300 DEG C, and then ground to obtain a mixed powder; the mixed powder is mixed with a precursor mixture of an elastic matrix, and then heated and solidified to obtain a stress distribution time-lapse imaging film.

[0009] The application mainly adopts a high-temperature solid phase method to synthesize a special mixed powder. 2+ The mixed powder is co-doped with Eu 3+ and Dy and other elements, which not only endows the prepared stress distribution time-lapse imaging film with the property of thermoluminescence, but also significantly enhances the stress luminescence intensity, effectively solving the problem of low stress luminescence intensity of the existing stress luminescence elastic film in the time-lapse stress display.

[0010] Specifically, the preparation process of the application involves uniformly mixing the mixed powder and a precursor mixture of an elastic matrix. The elastic matrix serves as a support platform, which not only provides a stable foundation for the mixed powder to withstand various stress forms such as torsion, stretching, friction, folding and tearing, but also ensures the overall flexibility and practicality of the stress distribution time-lapse imaging film. Then, the stress luminescence elastic film with stress sensitivity and thermoluminescence properties is formed by heating and solidification.

[0011] The stress luminescence elastic film prepared by the application has the unique feature that, when stress is applied and then removed for a period of time, the stress luminescence elastic film clearly displays the pattern of stress distribution through the thermoluminescence mechanism. This process not only realizes the time-lapse visualization of stress distribution, but also significantly improves the stress luminescence effect due to the co-doping strategy of multiple elements, making the stress distribution time-lapse imaging more distinct and persistent.

[0012] Therefore, the application prepares a thermoluminescence mixed powder co-doped with multiple elements by a high-temperature solid phase method, and combines it with a precursor mixture of an elastic matrix to form a stress distribution time-lapse imaging film that can display stress distribution through thermoluminescence after the stress is removed, and has high luminescence intensity.

[0013] Preferably, the Sr source is SrCO3, the Eu source is Eu2O3, and the Dy source is Dy2O3. The application realizes higher intensity yellow stress luminescence through the co-doping of Eu 2+ and Dy 3+ .

[0014] Preferably, the molar ratio of the Sr source, silicon dioxide, Eu source and Dy source is 1.8-2:1:0.2-0.25:0.8-1.

[0015] In the present application, with the increase of the doping amount of the Eu source and the Dy source, the influence on the stress distribution time-lapse imaging film is that the different doping amount of the Eu source and the Dy source causes the stress distribution time-lapse imaging film to have different light emission intensity under the stress. Specifically, with the increase of the doping amount of the Eu source and the Dy source, the stress luminescence intensity of the stress distribution time-lapse imaging film presents a trend of first increasing and then decreasing.

[0016] Preferably, the mass ratio of the mixed powder and the precursor mixture of the elastic matrix is 1.0-1.7:1.

[0017] Preferably, the temperature of the heat curing is 65-85 DEG C. The time of the heat curing is 0.5-2 hours.

[0018] Preferably, the solvent used in the wet grinding is ethanol; the grinding time is 15-30 minutes.

[0019] Preferably, the drying temperature is 85-90 DEG C; the drying time is 10-20 minutes. In the present application, the purpose of the drying is to remove the solvent, to avoid the safety problems caused by the volume expansion due to the solvent volatilization during the subsequent high-temperature sintering, and to avoid the influence on the subsequent sintering.

[0020] Preferably, the precursor mixture of the elastic matrix comprises a basic component and a curing agent component; the mass ratio of the basic component and the curing agent component is 10:1; the basic component is a vinyl-containing polydimethylsiloxane prepolymer; and the curing agent component is a mixture of a hydrogen-containing silicone oil crosslinking agent, a platinum catalyst and an inhibitor.

[0021] Further preferably, the precursor mixture of the elastic matrix is Dow Corning SYLGARD 184 silicone rubber.

[0022] In the present application, the elastic matrix provides a carrier for the prepared mixed powder, which can be subjected to various stress application modes such as torsion, stretching, friction, folding and tearing. The mixed powder is a thermoluminescent powder; the full name of polydimethylsiloxane in English is Polydimethylsiloxane, which is abbreviated as PDMS.

[0023] The precursor mixture of the elastic matrix used in the present application is Dow Corning DC184, also known as Dow Corning SYLGARD 184 silicone rubber. The precursor mixture of the elastic matrix is a two-component kit product produced by Dow Corning Company, which comprises a basic component and a curing agent component. The basic component is a PDMS basic component, and the curing agent component mainly comprises a crosslinking agent of a silicon-based polymer, which functions to cure the PDMS. Specifically, the crosslinking agent of the silicon-based polymer is a hydrogen-containing silicone oil crosslinking agent. The basic component and the curing agent component are completely mixed in a weight ratio of 10:1, and are cured into a transparent elastic matrix with toughness.

[0024] And the PDMS basic component is usually in the form of liquid prepolymer, which needs to form an elastic matrix through cross-linking reaction; the cross-linking system of the elastic matrix is a platinum catalytic addition curing system; thus, the cross-linking system includes a vinyl-containing PDMS prepolymer, a hydrogen-containing silicone oil cross-linking agent, a platinum catalyst and an inhibitor; wherein the vinyl-containing PDMS prepolymer is denoted as Vi-PDMS; the hydrogen-containing silicone oil cross-linking agent is denoted as a Si-H group cross-linking agent; the addition of the platinum catalyst can accelerate the cross-linking reaction; the inhibitor is used to control the reaction speed and prevent premature curing.

[0025] The precursor mixture of the elastic matrix described in the application is not unique, and PU glue, Ecoflex glue and the like can also be used. Among them, PU glue is also called bottom glue and forming glue, and its chemical name is polyurethane resin. Ecoflex glue is also called Ecoflex rubber, which belongs to platinum-catalyzed silicone material. Compared with the two, Dow Corning SYLGARD 184 silicone rubber has more excellent elastic performance, and its usage rate and applicability are also higher.

[0026] The second aspect of the application provides a stress distribution time-lapse imaging film, which is prepared by the preparation method of the stress distribution time-lapse imaging film described in the first aspect.

[0027] The stress distribution time-lapse imaging film of the application can be charged by a light source, and when stimulated by external stress, it can emit yellow light with a wavelength of 570nm, and can display the stress distribution situation through thermoluminescence within a period of time after the stress is removed, realizing the effect of stress distribution time-lapse imaging.

[0028] The third aspect of the application provides an application of a stress distribution time-lapse imaging film as a stress luminescent body for realizing stress distribution time-lapse imaging detection, wherein the stress distribution time-lapse imaging film is the stress distribution time-lapse imaging film described in the second aspect.

[0029] Preferably, the specific application method is as follows:

[0030] The stress luminescent body is exposed to a light source to charge the stress luminescent body; stress is applied to the stress luminescent body; then the applied stress is removed, and the stress luminescent body is dark treated and heat treated; the thermoluminescence spectrum data and the thermoluminescence image of the stress luminescent body during the heat treatment are obtained; the thermoluminescence spectrum data and the thermoluminescence image are processed and analyzed to identify the stress distribution information of the stress luminescent body, and a stress distribution time-lapse imaging image is generated.

[0031] In the present application, the stress application methods include stretching, twisting, folding, tearing and friction of the material, etc., and the stress applied by different stress application methods is different. The thermoluminescence spectrum data is monitored and obtained in real time by using a spectrum acquisition device. The thermoluminescence image includes an image and a video. Through the generated stress distribution time-lapse imaging diagram, the stress distribution of the stress luminescent body at different time points can be directly observed, so as to evaluate the mechanical properties and durability.

[0032] The present application has the following beneficial effects:

[0033] 1. The present application mainly uses a high-temperature solid-phase method to synthesize a special mixed powder, which is co-doped with multiple elements such as Eu 2+ and Dy 3+ , etc. The mixed powder not only has the characteristics of thermoluminescence, but also significantly enhances the stress luminescence intensity of the prepared stress distribution time-lapse imaging film, effectively solving the problem of low stress luminescence intensity of the existing stress luminescent elastic film in the time-lapse stress display.

[0034] 2. The preparation process of the present application involves uniformly mixing the mixed powder and the precursor mixture of the elastic matrix. The elastic matrix serves as a support platform, which not only provides a stable foundation for the mixed powder to withstand various stress forms such as twisting, stretching, friction, folding and tearing, but also ensures the overall flexibility and practicality of the stress distribution time-lapse imaging film. Subsequently, through heating and curing, a stress luminescent elastic film with stress sensitivity and thermoluminescence characteristics is formed.

[0035] 3. The stress luminescent elastic film prepared by the present application has the unique feature that when stress is applied and then removed for a period of time, the stress luminescent elastic film clearly displays the stress distribution pattern through the thermoluminescence mechanism. This process not only realizes the time-lapse visualization of stress distribution, but also benefits from the co-doping strategy of multiple elements, significantly improves the stress luminescence effect, and makes the stress distribution time-lapse imaging more distinct and persistent.

[0036] 4. The stress distribution time-lapse imaging film prepared by the present application can be used as a stress luminescent body to realize stress distribution time-lapse imaging detection, has high sensitivity and accuracy, and can provide strong support for the evaluation of the mechanical properties and durability of the stress luminescent body. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a real photo of the Sr2SiO4:Eu 2+ ,Dy 3+ fluorescent powder sample prepared in Example 1.

[0038] Figure 2 are two different specifications of Sr2SiO4:Eu2+ Dy 3+ @Physical photos of PDMS elastic film samples. Wherein, (a) is Sr2SiO4:Eu 2+ Dy 3+ @Physical photos of PDMS elastic film samples; (b) is Sr2SiO4:Eu 2+ Dy 3+ @Physical photos of PDMS elastic film samples.

[0039] Figure 3 are different pattern templates. (a)~(e) are different pattern templates, respectively.

[0040] Figure 4 is Sr2SiO4:Eu 2+ Dy 3+ @Schematic diagram of stress distribution time-lapse imaging of PDMS elastic film sample as stress luminescent body. Wherein, (a1) is the pattern stress information recorded by pressing the pattern template shown in Figure 3 (b) of the figure on the energized stress luminescent body; (a2) is the stress distribution information presented in the form of thermoluminescence recorded after dark treatment and 70℃ heat treatment of the stress luminescent body for 2h.

[0041] Figure 5 is Sr2SiO4:Eu 2+ Dy 3+ @Schematic diagram of stress distribution time-lapse imaging of PDMS elastic film sample as stress luminescent body. Wherein, (a1) is the pattern stress information recorded by pressing the pattern template shown in Figure 3 (a) of the figure on the energized stress luminescent body; (a2) is the stress distribution information presented in the form of thermoluminescence recorded after dark treatment and 70℃ heat treatment of the stress luminescent body for 4h.

[0042] Figure 6 is Sr2SiO4:Eu 2+ Dy 3+ @Schematic diagram of cyclic use of PDMS elastic film sample as stress luminescent body for stress distribution time-lapse imaging. Wherein, (a) is the stress luminescent body after energization of ultraviolet light source; (b) is the pattern stress information recorded by pressing the pattern template shown in Figure 3Fig. 4 is a stress distribution information of the stress luminescent body after the pattern template shown in Fig. 3 is pressed on the stress luminescent body after energized by the ultraviolet light source; Fig. 5 is a stress distribution information presented in the form of thermoluminescence after the stress luminescent body corresponding to the stress distribution information of Fig. 4 is dark treated and heat treated at 70°C for 4h; Fig. 6 is the stress luminescent body after the stress distribution information of Fig. 5 disappears and continues to be energized by the ultraviolet light source; Fig. 7 is a stress luminescent image of the stress luminescent body of Fig. 6 under the action of the pattern template; and Fig. 8 is a stress luminescent image of the stress luminescent body of Fig. 7 under the action of the pattern template. Figure 3 Fig. 9 is a stress distribution information of the stress luminescent body after the pattern template shown in Fig. 8 is pressed on the stress luminescent body after energized by the ultraviolet light source; Fig. 10 is a stress distribution information presented in the form of thermoluminescence after the stress luminescent body corresponding to the stress distribution information of Fig. 9 is dark treated and heat treated at 50°C for 4h.

[0043] Figure 7 Fig. 11 is a stress luminescent image of the stress luminescent body after energized by the ultraviolet light source in Example 4 under the action of the pattern template and a representation of imaging fineness of the stress luminescent image. Wherein, Fig. 11(a) is a stress luminescent image of the stress luminescent body after energized by the ultraviolet light source in Example 4 under the action of the pattern template; Figs. 11(i)-(iv) are local enlarged images of the corresponding regions in Fig. 11(a); and Fig. 11(b) is a representation of imaging fineness of the stress luminescent image.

[0044] Figure 8 Fig. 12 is a thermoluminescence image of the stress luminescent body in Example 4 and a representation of imaging fineness of the thermoluminescence image. Wherein, Fig. 12(a) is a thermoluminescence image of the stress luminescent body; Figs. 12(i)-(iv) are local enlarged images of the corresponding regions in Fig. 12(a); and Fig. 12(b) is a representation of imaging fineness of the thermoluminescence image.

[0045] Figure 9 Fig. 13 is a graph showing the change of luminescent intensity of the luminescent region and dark region of the thermoluminescence image of the stress luminescent body in Example 4 with the delay time.

[0046] Figure 10 Fig. 14 is a thermoluminescence image of the stress distribution delay imaging film doped with Pr 3+ in Comparative Example 1 at different delay times. Wherein, Figs. 14(a)-(f) are thermoluminescence images of the stress distribution delay imaging film doped with Pr 3+ at delay times of 5min, 30min, 1h, 6h, 12h and 24h, respectively.

[0047] Figure 11 Fig. 15 is a graph showing the change of luminescent intensity of the luminescent region and dark region of the thermoluminescence image of the stress distribution delay imaging film doped with Pr 3+ in Comparative Example 1 with the delay time. DETAILED DESCRIPTION

[0048] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0049] All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative labor fall within the scope of protection of the present application.

[0050] The present application aims to provide a stress distribution delay imaging film which is simple to prepare, has high light emission intensity and is reasonable in cost, and a preparation method thereof. 2+ and Dy 3+ The present application aims to provide a stress distribution delay imaging film which is simple to prepare, has high light emission intensity and is reasonable in cost, and a preparation method thereof. The stress distribution delay imaging film prepared in the present application can display the stress distribution by thermoluminescence within a period of time after the stress is removed, realize the effect of stress distribution delay imaging, and improve the light emission intensity by multi-element co-doping, thereby solving the problem of low light emission intensity of the existing stress light-emitting elastic film.

[0051] The stress distribution delay imaging film of the present application can be charged by a light source, can emit yellow light with a wavelength of 570nm when stimulated by external stress, and can display the stress distribution by thermoluminescence within a period of time after the stress is removed, realize the effect of stress distribution delay imaging, and the delay time can be up to 24h. Within the delay time of 0h-4h, the light emission intensity of thermoluminescence gradually decreases to 50% of the initial light emission intensity, and within 4h-24h, the light emission intensity of thermoluminescence remains at 50% of the initial light emission intensity.

[0052] In the present application, the light source can be sunlight or a man-made charging light source with different wavelengths, for example, an SVC Wood's lamp with a power of 5W and a wavelength of 365nm. Of course, the light source can also be an ultraviolet lamp.

[0053] The stress distribution delay imaging film of the present application can be used as a stress light-emitting body for the application of stress distribution delay imaging detection. The specific application method is as follows:

[0054] S1, light source charging: exposing the stress light-emitting body to a light source to charge the stress light-emitting body.

[0055] S2, applying stress: applying stress to the stress light-emitting body.

[0056] S3, dark treatment and heat treatment: after removing the applied stress, dark treatment and heat treatment are performed on the stress light-emitting body.

[0057] S4, processing and analyzing: obtaining the thermoluminescence spectral data and thermoluminescence images of the stress luminescent body during the heat treatment process; processing and analyzing the thermoluminescence spectral data and the thermoluminescence images to identify the stress distribution information of the stress luminescent body, and generating a stress distribution time-lapse imaging map.

[0058] The application further provides a stress detection system, which comprises a stress luminescent body, a light source, a stress applying device, a stress luminescence spectral detection device and a data processing module.

[0059] The stress applying device is used for applying stress to the stress luminescent body, and the stress is applied in the form of stretching, twisting, folding, tearing and friction of materials.

[0060] The stress luminescence spectral detection device is an Ocean QEpro spectrometer connected with an optical fiber, which is used for real-time monitoring and collecting the thermoluminescence spectral data and thermoluminescence images of the stress luminescent body during the heat treatment process, and sending the thermoluminescence spectral data and thermoluminescence images to the data processing module.

[0061] The data processing module comprises Origin2021 data processing software and Adobe PhotoShop software, which can receive the thermoluminescence spectral data and thermoluminescence images, and process and analyze the received thermoluminescence spectral data and thermoluminescence images to identify the stress distribution information of the stress luminescent body and generate a stress distribution time-lapse imaging map.

[0062] In the application, the stress distribution time-lapse imaging map can be used to intuitively see the stress distribution of the stress luminescent body at different time points, so as to evaluate the mechanical properties and durability thereof.

[0063] The technical solutions of the application are further described below through specific embodiments.

[0064] In each of the following embodiments, the method is a conventional method unless otherwise specified; and the reagents and materials can be commercially available unless otherwise specified.

[0065] The equipment used in the following examples includes a Wood's lamp with a power of 5W and a wavelength of 365nm; a film stretching platform; an Ocean QEPro spectrometer connected with an optical fiber; a thermoluminescence heating platform, wherein the model of the thermoluminescence heating platform is JFTOOLS JF966-1520.

[0066] The precursor mixture of the elastic matrix is Dow Corning SYLGARD 184 silicone rubber, which is a two-component kit product produced by Dow Corning Company, including a basic component and a curing agent component. The basic component is a PDMS basic component, and the curing agent component is a mixture of hydrogen-containing silicone oil crosslinking agent, platinum catalyst and inhibitor. The basic component and the curing agent component are completely mixed at a weight ratio of 10:1, and are cured into a transparent elastic matrix with toughness. The PDMS basic component is a vinyl-containing polydimethylsiloxane prepolymer, simply referred to as a vinyl-containing PDMS prepolymer, with a molecular weight range of about 3000-50000, and the molecular weight of the repeating unit is 74, so the polymerization degree is estimated to be between 40 and 675.

[0067] Example 1

[0068] A preparation method of a stress distribution time-lapse imaging film, comprising the following steps:

[0069] Step 1, preparation of Sr2SiO4:Eu 2+ ,Dy 3+ phosphor sample.

[0070] According to the stoichiometric ratio of SrCO3, SiO2, Eu2O3 and Dy2O3, the molar ratio is 2:1:0.25:1. The powder raw materials are weighed; SrCO3, SiO2, Eu2O3 and Dy2O3 are mixed in an agate mortar to obtain a mixed powder raw material. Take 4.2696g of the mixed powder raw material, add 15mL of anhydrous ethanol and grind for 30 minutes, and then put the ground mixed powder raw material into a 90℃ oven for drying for 15 minutes to remove the solvent, so as to avoid the safety problems caused by the volume expansion due to solvent volatilization during subsequent high-temperature sintering and to avoid the influence on subsequent sintering.

[0071] The dried mixed powder raw material is transferred to a crucible, and then the crucible is placed in a high-temperature muffle furnace and sintered at 1250℃ for 4 hours. After cooling to room temperature, the cooled sample is taken out and ground into powder in a mortar to obtain a sintered mixed powder; denoted as Sr2SiO4:Eu 2+ ,Dy 3+ phosphor sample.

[0072] Step 2, preparation of Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample.

[0073] The sintered mixed powder and the precursor mixture of Dow Corning SYLGARD 184 silicone rubber were mixed at a mass ratio of 1:1, stirred uniformly, and then transferred into an oven for heating and curing at 70°C for 1 hour to obtain a stress distribution time-lapse imaging film; denoted as Sr2SiO4:Eu 2+ ,Dy 3+ The actual photos of the PDMS elastic film samples are shown in FIG. 2.

[0074] In Example 1, Sr2SiO4:Eu 2+ ,Dy 3+ The actual photos of the fluorescent powder samples are shown in FIG. 1. Figure 1 In Example 2, Sr2SiO4:Eu 2+ ,Dy 3+ The actual photos of the PDMS elastic film samples are shown in FIG. 2. Figure 2

[0075] Example 2

[0076] A method for preparing a stress distribution time-lapse imaging film, comprising the following steps:

[0077] Step 1, preparing Sr2SiO4:Eu 2+ ,Dy 3+ fluorescent powder sample.

[0078] The powder raw materials of SrCO3, SiO2, Eu2O3 and Dy2O3 were weighed according to the stoichiometric ratio of 2:1:0.2:1, mixed in an agate mortar to obtain mixed powder raw materials. 4.27 g of the mixed powder raw materials were taken, added with 15 mL of anhydrous ethanol for grinding for 30 minutes, and the ground mixed powder raw materials were placed in a 90°C oven for drying for 15 minutes to remove the solvent, so as to avoid the safety problems caused by the volume expansion due to solvent volatilization during subsequent high-temperature sintering and the influence on subsequent sintering.

[0079] The dried mixed powder raw materials were transferred to a crucible, and then the crucible was placed in a high-temperature muffle furnace for sintering at 1200°C for 3 hours. After cooling to room temperature, the cooled sample was taken out and ground into powder in a mortar to obtain sintered mixed powder; denoted as Sr2SiO4:Eu 2+ ,Dy 3+ fluorescent powder sample.

[0080] Step 2, preparing Sr2SiO4:Eu 2+ ,Dy 3+ PDMS elastic film sample.

[0081] ​The sintered mixed powder and the precursor mixture of Dow Corning SYLGARD 184 silicone rubber are mixed at a mass ratio of 1.5:1, stirred uniformly, and then transferred into an oven for heating and curing at 65°C for 2 hours to obtain a stress distribution time-lapse imaging film; denoted as Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample.

[0082] Example 3

[0083] A preparation method of a stress distribution time-lapse imaging film, comprising the following steps:

[0084] Step 1, preparation of Sr2SiO4:Eu 2+ ,Dy 3+ fluorescent powder sample.

[0085] The raw powders of SrCO3, SiO2, Eu2O3 and Dy2O3 are weighed according to the stoichiometric ratio of 1.8:1:0.2:0.8, and then mixed in an agate mortar to obtain a mixed powder raw material. 4.27g of the mixed powder raw material is taken, 15mL of anhydrous ethanol is added, and grinding is performed for 30 minutes. The ground mixed powder raw material is placed in a 90°C oven for drying for 15 minutes to remove the solvent, so as to avoid the safety problems caused by the volume expansion due to solvent volatilization during subsequent high-temperature sintering and to avoid the influence on subsequent sintering.

[0086] The dried mixed powder raw material is transferred to a crucible, and then the crucible is placed in a high-temperature muffle furnace for sintering at 1300°C for 4 hours. After cooling to room temperature, the cooled sample is taken out and ground into powder in a mortar to obtain a sintered mixed powder; denoted as Sr2SiO4:Eu 2+ ,Dy 3+ fluorescent powder sample.

[0087] Step 2, preparation of Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample.

[0088] The sintered mixed powder and the precursor mixture of Dow Corning SYLGARD 184 silicone rubber are mixed at a mass ratio of 1.7:1, stirred uniformly, and then transferred into an oven for heating and curing at 85°C for 1 hour to obtain a stress distribution time-lapse imaging film; denoted as Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample.

[0089] The Sr2SiO4:Eu 2+ ,Dy3+ The application of the PDMS elastic film sample as a stress luminescent body in the stress distribution time-lapse imaging detection aspect is specifically described as follows.

[0090] Application Example 1

[0091] The Sr2SiO4:Eu 2+ ,Dy 3+ The application of the PDMS elastic film sample as a stress luminescent body in the stress distribution time-lapse imaging detection aspect is specifically described as follows.

[0092] S1, light source charging: the Sr2SiO4:Eu 2+ ,Dy 3+ The PDMS elastic film sample is used as a stress luminescent body; a Wood's lamp with a power of 5 W and a wavelength of 365 nm is used as a light source, and the stress luminescent body is exposed to the light source for 5 minutes to charge the stress luminescent body.

[0093] S2, stress application: a pattern template shown in FIG. (b) of Figure 3 is pressed on the stress luminescent body charged in step S1 for 8 seconds. After the pattern template is removed, the corresponding pattern on the pattern template is visible in the form of stress luminescence on the stress luminescent body, as shown in FIG. (a1) of Figure 4 .

[0094] S3, dark treatment and heat treatment: the stress luminescent body is then dark treated and transferred to a thermoluminescence heating platform for heat treatment at 70℃ for 2 h. The over-stressed pattern area on the stress luminescent body is displayed in the form of thermoluminescence, achieving the effect of stress distribution time-lapse imaging, as shown in FIG. (a2) of Figure 4 .

[0095] Application Example 2

[0096] The Sr2SiO4:Eu 2+ ,Dy 3+ The application of the PDMS elastic film sample as a stress luminescent body in the stress distribution time-lapse imaging detection aspect is specifically described as follows.

[0097] S1, light source charging: the Sr2SiO4:Eu 2+ ,Dy 3+ The PDMS elastic film sample is used as a stress luminescent body; a Wood's lamp with a power of 5 W and a wavelength of 365 nm is used as a light source, and the stress luminescent body is exposed to the light source for 5 minutes to charge the stress luminescent body.

[0098] S2, stress application: a pattern template shown in FIG. (b) of Figure 3The pattern template shown in Figure (a) is pressed onto the stress-emitting body after charging in step S1 for 8 seconds. After the pattern template is removed, the corresponding pattern on the pattern template is visible to the naked eye on the stress-emitting body in the form of stress luminescence, as shown in Figure (a). Figure 5 As shown in Figure (a1).

[0099] S3. Dark Processing and Heat Treatment: The stress-emitting body is then dark-processed and transferred to a thermoluminescent heating platform for heat treatment at 70°C for 4 hours. The patterned areas on the stress-emitting body that have been subjected to stress are displayed in the form of thermoluminescence, achieving a time-lapse imaging effect of stress distribution. Figure 5 As shown in Figure (a2).

[0100] Application Example 3

[0101] The Sr2SiO4:Eu prepared in Example 1 2+ ,Dy 3+ @PDMS elastic thin film samples are used as stress luminescent materials for the application of time-lapse imaging and cyclic detection of stress distribution. The specific application method is as follows:

[0102] S1, Light source charging: The Sr2SiO4:Eu prepared in Example 1 is charged. 2+ ,Dy 3+ @PDMS elastic film sample was used as a stress luminescent material; using an ultraviolet lamp as a light source, the stress luminescent material was exposed to the light source to charge it for 5 minutes, such as... Figure 6 As shown in Figure (a).

[0103] S2, Applying stress: with Figure 3 The pattern template shown in Figure (d) is pressed onto the stress-emitting body after charging in step S1 for 8 seconds. After removing the pattern template, the pattern stress information is recorded, such as... Figure 6 As shown in Figure (b).

[0104] S3. Dark Treatment and Heat Treatment: The stress-emitting body was then subjected to dark treatment and simultaneously transferred to a thermoluminescence heating platform for heat treatment at 70°C for 4 hours. The stress distribution information, presented in the form of thermoluminescence, was recorded. Figure 6 As shown in Figure (c).

[0105] S4. Light Source Charging: After the stress distribution information disappears, continue using an ultraviolet lamp as the light source to expose the stress-emitting body to the light source for 5 minutes to charge it. Figure 6 As shown in Figure (d).

[0106] S5, Apply stress: with Figure 3The pattern template shown in (c) of FIG. 1 is pressed on the stress luminescent body charged in step S4 for 6 seconds. After the pattern template is removed, the stress information of the pattern is recorded, as shown in (d) of FIG. 1. Figure 6 as shown in (e) of FIG. 1.

[0107] S6, dark treatment and heat treatment: the stress luminescent body is then dark treated for 4 hours, and is simultaneously transferred to a thermoluminescence heating platform to be heat treated at 50℃ for 4 hours. The stress distribution information presented in the form of thermoluminescence is recorded, as shown in (f) of FIG. 1. Then, the process returns to step S1. Figure 6

[0108] Figure 6 The cycle performance of the stress luminescent body is demonstrated, that is, a cycle of “light source charging, stress applying, dark treatment and heat treatment”. After the cycle is completed, the stress luminescent body can be charged again to enter the next cycle.

[0109] The Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample prepared in Example 1 is used as a stress luminescent body, and the temperature range of use is between -50℃ and +200℃. In the dark treatment and heat treatment steps, the stress distribution information is mainly displayed through thermoluminescence. In this step, the heating temperature of the stress luminescent body is 50℃ to 70℃. Within this heating temperature range, the stress luminescent body can be completely used normally, and there is no problem of internal or external film body structural damage.

[0110] In terms of mechanical properties, the Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample prepared in Example 1 is used as a stress luminescent body, and the damage pressure threshold is 2MPa to 5MPa. In the stress applying step, the stress luminescent body is applied with a stress in a pressure range of 10kPa to 20kPa. Within this pressure range, the stress luminescent body can be completely used normally, and there is no problem of internal or external film body structural damage.

[0111] Through the cycle test, it is found that the Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample prepared in Example 1 is used as a stress luminescent body, and the number of uses can reach at least 500 times.

[0112] Application Example 4

[0113] The Sr2SiO4:Eu 2+ ,Dy 3+ ​@PDMS elastic thin film samples are used as stress luminescent materials for time-lapse imaging detection of stress distribution. The specific application method is as follows:

[0114] S1, Light source charging: The Sr2SiO4:Eu prepared in Example 1 is charged. 2+ ,Dy 3+ The PDMS elastic film sample was used as a stress luminescent material; an ultraviolet lamp was used as a light source to expose the stress luminescent material to the light source to charge it for 5 minutes.

[0115] S2, Applying stress: with Figure 3 The pattern template shown in Figure (e) is pressed onto the stress-emitting body after charging in step S1 for 8 seconds. After the pattern template is removed, the corresponding pattern on the pattern template is visible to the naked eye on the stress-emitting body in the form of stress luminescence, such as... Figure 7 As shown in Figure (a).

[0116] S3. Dark Processing and Heat Treatment: The stress-emitting body is then dark-processed and transferred to a thermoluminescent heating platform for heat treatment at 70°C for 4 hours. The patterned areas on the stress-emitting body that have been subjected to stress are displayed in the form of thermoluminescence, achieving a time-lapse imaging effect of stress distribution. Figure 8 As shown in Figure (a).

[0117] Figure 7 This is a stress-emitting image of the stress-emitting body after being charged by the light source in Application Example 4, under the action of the pattern template, and a characterization diagram of the imaging fineness of the stress-emitting image. Among them, (a) is a stress-emitting image of the stress-emitting body after being charged by the light source in Application Example 4, under the action of the pattern template; (i) to (iv) are magnified views of the corresponding areas in (a); (b) is a characterization diagram of the imaging fineness of the stress-emitting image.

[0118] Depend on Figure 7 It can be seen that the average precision of the stress-luminescent image under the action of the pattern template can reach 0.6488mm±0.1988mm.

[0119] Figure 8 This is a thermoluminescence image of the stress luminescent body in Application Example 4, and a characterization diagram of the imaging fineness of the thermoluminescence image. Among them, (a) is a thermoluminescence image of the stress luminescent body; (i) to (iv) are magnified views of the corresponding areas in (a); and (b) is a characterization diagram of the imaging fineness of the thermoluminescence image.

[0120] Depend on Figure 8 It can be seen that the average resolution of thermoluminescent images can reach 0.7072mm ± 0.2041mm.

[0121] The formula for calculating the signal-to-noise ratio is: signal-to-noise ratio = luminescence intensity of the luminescence area / luminescence intensity of the dark area.

[0122] Wherein, the higher the signal-to-noise ratio, the clearer the pattern is visible. The luminescence area corresponds to the stress distribution area, and the dark area corresponds to the non-stress distribution area.

[0123] Figure 9 is the luminescence intensity of the luminescence area and the dark area of the thermoluminescence image of the stress luminescent body in application example 4 as a function of the delay time.

[0124] By Figure 9 It is shown that the Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample as a stress luminescent body can be used to realize stress distribution delay imaging detection, and the delay time can reach 24h; within 0h-4h of the delay time, the luminescence intensity of the thermoluminescence gradually decreases to 50% of the initial luminescence intensity; within 4h-24h, the luminescence intensity of the thermoluminescence is maintained at 50% of the initial luminescence intensity.

[0125] It is shown that the Sr2SiO4:Eu 2+ ,Dy 3+ @PDMS elastic film sample as a stress luminescent body has higher luminescence intensity when used to realize stress distribution delay imaging detection, and has higher signal-to-noise ratio and clearer pattern.

[0126] Application Comparative Example 1

[0127] A stress distribution delay imaging film doped with Pr 3+ is used as a stress luminescent body to realize stress distribution delay imaging detection. Reference from document 1: Controllable Modulation of Trapped Carriers in Mechano / Thermo Dual‐Responsive Particles for Advanced Stress‐Encoded Information Storage, DOI: 10.1002 / lpor.202400229. The Chinese name of document 1 is: Controllable Modulation of Trapped Carriers in Mechano / Thermo Dual‐Responsive Particles for Advanced Stress‐Encoded Information Storage.

[0128] Figure 10 is the thermoluminescence image of the stress distribution delay imaging film doped with Pr 3+ in application comparative example 1 under different delay times. Wherein, (a)-(f) are respectively the thermoluminescence images of the stress distribution delay imaging film doped with Pr 3+Thermoluminescence images of the stress distribution time-lapse imaging film at time delay times of 5 min, 30 min, 1 h, 6 h, 12 h and 24 h.

[0129] Figure 11 It is the application of Pr doping in Comparative Example 1 3+ The graph shows the variation of luminescence intensity in the luminescent and dark regions of the thermoluminescent thin film in the time-delay imaging of stress distribution.

[0130] Depend on Figure 10 It can be seen that the Pr doping in Comparative Example 1 is applied 3+ The stress distribution time-lapse imaging film emits red light when stimulated by external stress. It can display the stress distribution through thermoluminescence within 24 hours after the stress is removed, thus achieving time-lapse imaging of stress distribution. Moreover, after half an hour of stress removal, the intensity of its thermoluminescence drops to 50% of the initial intensity; after 6 hours, it drops to about 30% of the initial intensity; and after 24 hours, it is difficult to distinguish with the naked eye.

[0131] Depend on Figure 11 It can be seen that as the delay time increases, the difference in luminous intensity between the luminous and dark regions gradually decreases, which can also be understood as the signal-to-noise ratio (SNR) of the time-lapse imaging gradually decreasing over a certain period of time. Specifically, at 0h, the luminous intensity of the luminous region is 58, and the luminous intensity of the dark region is 28, resulting in an SNR of approximately 2.07. The SNR then gradually decreases; at a delay time of 24h, the luminous intensity of the luminous region is 29, and the luminous intensity of the dark region is 18, at which point the SNR is at its lowest, approximately 1.61.

[0132] Depend on Figure 9 As can be seen, the stress-emitting body in Application Example 4 can emit yellow light with a wavelength of 570nm when stimulated by external stress. It can display the stress distribution through thermoluminescence within 24 hours after the stress is removed, realizing time-lapse imaging of stress distribution. When the delay time is 2h, the signal-to-noise ratio of the emitting area to the dark area is 3.17; when the delay time is 4h, the signal-to-noise ratio of the emitting area to the dark area is approximately 2.38.

[0133] The above analysis results show that, compared with Comparative Example 1, the Sr2SiO4:Eu prepared in Examples 1 to 3 of this invention... 2+ ,Dy 3+ @PDMS elastic film samples, used as stress luminescent materials in time-lapse imaging of stress distribution detection, exhibit higher luminescence intensity, higher signal-to-noise ratio, and clearer patterns.

[0134] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a stress distribution time-lapse imaging film, characterized by, The method comprises the following steps: The Sr source, the silicon dioxide, the Eu source and the Dy source are mixed by wet grinding, dried, sintered at 1200-1300 DEG C, and then ground to obtain a mixed powder; the molar ratio of the Sr source, the silicon dioxide, the Eu source and the Dy source is 1.8-2:1:0.2-0.25:0.8-1; The mixed powder is mixed with a precursor mixture of an elastic matrix, and then heated and solidified to obtain a stress distribution time-lapse imaging film.

2. The method of claim 1, wherein the stress distribution time-lapse imaging film is prepared by the steps of: The Sr source is SrCO3; the Eu source is Eu2O3; and the Dy source is Dy2O3.

3. The method for preparing a stress distribution time-delay imaging thin film according to claim 1, characterized in that, The mass ratio of the mixed powder and the precursor mixture of the elastic matrix is 1.0-1.7:

1.

4. The method of claim 1, wherein the stress distribution time-lapse imaging film is prepared by the steps of: The temperature of the heating and solidification is 65-85 DEG C.

5. The method of claim 1, wherein the stress distribution time-lapse imaging film is prepared by the steps of: The precursor mixture of the elastic matrix comprises a basic component and a curing agent component; the mass ratio of the basic component and the curing agent component is 10:

1. The basic component is a vinyl-containing polydimethylsiloxane prepolymer; the curing agent component is a mixture of hydrogen-containing silicone oil crosslinking agent, platinum catalyst and inhibitor.

6. A stress distribution time-lapse imaging film, characterized by, The stress distribution time-lapse imaging film is prepared by the preparation method of any one of claims 1-5.

7. The use of a stress distribution time-lapse imaging film as a stress luminescer for stress distribution time-lapse imaging detection, characterized in that, The stress distribution time-lapse imaging film is the stress distribution time-lapse imaging film of claim 6.

8. The stress distribution time-lapse imaging film according to claim 7, as an application of stress luminescent body for realizing stress distribution time-lapse imaging detection, characterized in that, The specific application method is as follows: The stress luminescent body is exposed to a light source to charge the stress luminescent body; Stress is applied to the stress luminescent body, and then the applied stress is removed, and the stress luminescent body is dark treated and heat treated; Thermoluminescence spectral data and thermoluminescence images of the stress luminescent body during heat treatment are obtained; The thermoluminescence spectral data and the thermoluminescence images are processed and analyzed to identify stress distribution information of the stress luminescent body, and a stress distribution time-lapse imaging image is generated.

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