Green electroluminescent composite elastic material and preparation method thereof

Abstract

This invention belongs to the field of inorganic solid-state luminescent materials technology, and discloses a green mechanoluminescent composite elastic material and its preparation method, comprising an elastic matrix and a green mechanoluminescent phosphor dispersed in the elastic matrix, wherein the chemical formula of the green mechanoluminescent phosphor is Ba. 0.79 Al 10.9‑x O 17.14 :xMn 2+ (0 < x ≤ 0.35). This green mechanoluminescent composite elastomer still exhibits bright green mechanoluminescence after more than 15,000 tensile cycles. By writing characters on the composite elastomer and mapping the luminescence intensity to different colors, the color changes caused by different stress magnitudes can be clearly observed. This indicates that the prepared mechanoluminescent composite elastomer has great potential in applications such as electronic signatures, anti-counterfeiting, and structural health monitoring.

Description

Technical Field

[0001] This invention belongs to the field of inorganic solid luminescent materials technology, specifically relating to a green mechanoluminescent composite elastic material and its preparation method. Background Technology

[0002] Mechanoluminescence (ML) is an optical phenomenon in which a material directly converts mechanical energy into light energy, typically excited by external mechanical stimuli such as pressure, tension, friction, or impact. This phenomenon was observed and recorded centuries ago, but its mechanism has only become clear in recent years with advancements in materials science and optoelectronic technology, allowing for deeper exploration of its application potential. Compared to the structural rigidity of traditional inorganic phosphors and the stability limitations of organic polymer materials, embedding inorganic luminescent components into flexible organic matrices can construct composite elastomer systems that possess excellent mechanical properties, chemical stability, and recoverable luminescence. These materials are not only easy to prepare but also exhibit high sensitivity, reproducible luminescence, and good environmental adaptability, demonstrating significant application value in several cutting-edge fields such as flexible sensing, structural health monitoring, wearable devices, human-computer interaction, and visual anti-counterfeiting.

[0003] The most typical mechanoluminescent composite system currently uses ZnS:Cu phosphor as the luminescent center dispersed in a polydimethylsiloxane (PDMS) elastic matrix. While this ZnS:Cu / PDMS composite exhibits good mechanical durability, maintaining bright and persistent green luminescence even after 10,000 repeated mechanical stimuli, this system also has significant limitations. Its core luminescent component, ZnS, is a sulfide, which is chemically unstable, resulting in poor material stability. After even more repeated mechanical stimuli, the luminescent performance cannot be guaranteed, thus limiting its application in more diverse scenarios.

[0004] Besides the typical ZnS:Cu / PDMS system, other PDMS-based composite elastic materials also face challenges in mechanical durability. For example, the high-brightness, long-afterglow material SrAl2O4:Eu... 2+ While composites with PDMS can achieve significant mechanoluminescence in the initial stage, their mechanical stability is often insufficient. In repeated bending or compression tests, the luminescence performance of these composites decays rapidly, typically only withstanding hundreds to thousands of cycles. The main reason is the weak interfacial bonding between the brittle phosphor particles and the elastomer matrix, which easily leads to microcracks or delamination under cyclic stress, resulting in stress transfer failure and weakened luminescence. Therefore, achieving high cycle stability and multifunctional integrated applications are currently critical bottlenecks that need to be addressed in PDMS-based composite elastic materials. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to provide a green mechanoluminescent composite elastic material and its preparation method. The composite material of this invention can still maintain stable green luminescence after undergoing 15,000 repeated mechanical stretching cycles.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A green mechanoluminescent composite elastic material includes an elastic matrix and a green mechanoluminescent phosphor dispersed in the elastic matrix; the general chemical formula of the green mechanoluminescent phosphor is: Ba 0.79 Al 10.9-x O 17.14 :xMn 2+ , where 0 < x ≤ 0.35.

[0007] Preferably, the elastic matrix is ​​a polydimethylsiloxane elastic matrix.

[0008] The present invention also provides a method for preparing the green mechanoluminescent composite elastic material as described above, comprising the following steps: The green mechanoluminescent phosphor is mixed with the raw materials of the elastic matrix and then cured to obtain the green mechanoluminescent composite elastic material.

[0009] Preferably, the preparation process of the green mechanoluminescent phosphor includes: The raw material powder of green metronome phosphor is mixed evenly to obtain a raw material mixture; The raw material mixture was pre-calcined at 800-1000℃ for 4-6 hours. After pre-calcination, it was cooled to room temperature, then ground into powder and mixed to obtain an intermediate. The intermediate is pressed into a sheet-like molded body; The sheet-shaped body was calcined in a reducing atmosphere at 1300–1500°C for 4–6 h. After calcination, it was naturally cooled to room temperature and ground into powder to obtain the green mechanoluminescent phosphor.

[0010] Preferably, the raw material for the green mechanoluminescent phosphor is a compound powder containing Ba, Al, O and Mn elements.

[0011] Preferably, the raw material powders for the green mechanoluminescent phosphor are BaCO3 powder, Al2O3 powder and MnCO3 powder.

[0012] Preferably, when the intermediate is pressed into a sheet-like molded body, the pressure used during the pressing process is 13 to 15 MPa.

[0013] Preferably, the reducing atmosphere is a mixture of hydrogen and an inert gas, wherein the volume fraction of H2 is 10% to 20%.

[0014] Preferably, the inert gas includes at least one of nitrogen and helium.

[0015] Preferably, the raw materials of the elastic matrix include polydimethylsiloxane and a curing agent, and the mass ratio of the green mechanoluminescent phosphor, polydimethylsiloxane and curing agent is (1-2):(1.9-2.1):(0.18-0.22). During curing, the curing temperature is 70–80 ℃ and the curing time is 0.5–2 h.

[0016] The present invention has the following beneficial effects: The green mechanoluminescent composite elastic material provided by this invention uses an elastic matrix as a carrier to disperse a green mechanoluminescent phosphor Ba with a specific chemical composition. 0.79 Al 10.9-x O 17.14 :xMn 2+ (0 < x ≤ 0.35), by using oxide-based phosphors to replace traditional sulfide luminescent components, the chemical stability of the material is improved from its intrinsic nature, effectively avoiding the problems of easy decomposition and poor stability of the existing ZnS:Cu system. Experimental verification of this invention shows that the aluminate-structured phosphor has better interfacial compatibility with the elastic matrix, which can improve the problems of weak bonding between traditional brittle phosphors and the matrix, and the tendency to generate microcracks or delamination under cyclic stress. This significantly improves the cyclic stability and luminescence durability of the material under repeated mechanical stimulation (experiments showed that under 3Hz frequency and 50% tensile strain conditions, the composite material of this invention can still maintain stable green luminescence after 15,000 repeated mechanical stretching cycles). Therefore, the composite elastic material of this invention can maintain stable green mechanoluminescence under long-term, high-frequency mechanical action, while simultaneously controlling Mn... 2+ The doping concentration allows for controllable adjustment of luminescence intensity, balancing luminescence performance and structural stability. This effectively addresses the technical bottlenecks of insufficient mechanical durability and easy degradation during recycling of existing mechanoluminescent composite elastic materials, providing a more stable and reliable material option for fields such as flexible sensing, structural health monitoring, and visual anti-counterfeiting. Attached Figure Description

[0017] Figure 1 Different Mn samples prepared according to Examples 1-6 of this invention 2+ X-ray diffraction patterns of phosphors with varying doping concentrations; Figure 2 Different Mn samples prepared according to Examples 1-6 of this invention 2+ Mechanoluminescence spectrum of composite elastic materials with high doping concentration (test conditions: 3 Hz frequency and 50% tensile strain); Figure 3The images show the mechanoluminescence spectra of the composite elastic material prepared in Example 4 of this invention under different tensile strains. Figure 4 This is a fitting graph of the mechanoluminescence intensity of the composite elastic material prepared in Example 4 of the present invention under different tensile strains; Figure 5 The tensile repeatability test diagram of the composite elastic material prepared in Example 4 of the present invention (test conditions are 3 Hz frequency and 50% tensile strain). Figure 6 Digital photographs and pressure mappings of the letter “XAUAT” written on the composite elastic material prepared in Example 4. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the embodiments and accompanying drawings. This is merely an explanation of the present invention, and the feasible implementation methods of the present invention are not limited thereto.

[0019] This invention relates to a green mechanoluminescent composite elastic material, comprising an elastic matrix and a green mechanoluminescent phosphor dispersed in the elastic matrix; the general chemical formula of the green mechanoluminescent phosphor is: Ba 0.79 Al 10.9-x O 17.14 :xMn 2+ , where 0 < x ≤ 0.35.

[0020] The preparation method of the above-mentioned green mechanoluminescent phosphor of the present invention includes the following steps: Step (1): Mix the raw materials required for preparing green mechanoluminescent phosphor evenly according to the stoichiometric ratio to obtain a raw material mixture; wherein, the raw materials required for preparing green mechanoluminescent phosphor are compounds containing Ba, Al, O and Mn elements. More specifically, the raw materials required for preparing green mechanoluminescent phosphor can be BaCO3 powder, Al2O3 powder and MnCO3 powder.

[0021] Step (2): Pre-calcine the raw material mixture in step (1) at 800-1000 °C for 4-6 h. After pre-calcine, cool to room temperature, grind into powder and mix evenly to obtain an intermediate. Step (3): Press the intermediate from step (2) into a sheet-shaped molded body; wherein the shape of the sheet-shaped molded body can be circular, and the pressure used when pressing it into a circular sheet is 13 to 15 MPa.

[0022] Step (4): Place the sheet-shaped molded body described in step (3) in a crucible and calcine it at high temperature in a tube furnace under a reducing atmosphere. The calcine temperature is 1300–1500°C, and the calcine time is 4–6 h. The reducing atmosphere can be a mixture of hydrogen and an inert gas. The volume fraction of H2 in the mixture is 10%–20%. The inert gas can be at least one of nitrogen and helium. After calcine, allow it to cool naturally to room temperature and grind it into powder to obtain the green mechanoluminescent phosphor.

[0023] In the above-described scheme of the present invention, the elastic matrix can be a polydimethylsiloxane (PDMS) elastic matrix, the raw materials of which include polydimethylsiloxane and curing agent.

[0024] The process of preparing the green mechanoluminescent composite elastic material of the present invention using the above-mentioned green mechanoluminescent phosphor and elastic matrix raw materials includes: The green metronic phosphor obtained in step (4) above is mixed evenly with the raw materials of polydimethylsiloxane elastic matrix (i.e., polydimethylsiloxane (also known as PDMS colloid) and curing agent) in a ratio of (1-2):(1.9-2.1):(0.18-0.22), then placed in a petri dish and placed in an oven to cure at 70-80 °C for 0.5-2 h to obtain the green metronic luminescent composite elastic material of the present invention.

[0025] Example 1 In this embodiment, the green mechanoluminescent composite elastic material contains a green mechanoluminescent phosphor with the general chemical formula: Ba. 0.79 Al 10.80 O 17.14 : 0.10 Mn 2+ (i.e., x=0.10), the preparation method of this green mechanoluminescent composite elastic material includes the following steps: Step (1), according to the chemical formula Ba 0.79 Al 10.80 O 17.14 : 0.10 Mn 2+The stoichiometric ratios of the elements were accurately determined by weighing 3.95 mmol BaCO3 powder, 27.00 mmol Al2O3 powder, and 0.50 mmol MnCO3 powder. The BaCO3, Al2O3, and MnCO3 powders were ground and mixed thoroughly, then placed in an alumina crucible and pre-fired in a box furnace. The temperature was raised to 800 °C and held for 6 hours. After natural cooling to room temperature, the mixture was discharged, ground into powder, and mixed evenly to obtain an intermediate. The intermediate was then pressed into disc-shaped pieces using a tablet press (pressure set to 13 MPa). These disc-shaped pieces were placed in a graphite crucible and then placed in a tube furnace with a mixed atmosphere of 20% H2-80% N2 (volume ratio). The temperature was raised to 1300 °C and held for 6 hours. After natural cooling to room temperature, the mixture was discharged, cooled, and ground into powder to obtain a high-purity green mechanoluminescent phosphor sample.

[0026] Step (2): Take the Ba obtained in step (1) 0.79 Al 10.80 O 17.14 : 0.10 Mn 2+ The green mechanoluminescent phosphor sample was mixed with PDMS colloid (Dow Corning SYLGARD 184 as the main agent in this embodiment) and curing agent (Dow Corning SYLGARD 184 as the curing agent in this embodiment) at a mass ratio of 1.5:2:0.2, with 1 g of phosphor as the reference. The well-mixed sample was transferred to a cuvette and then placed in a 70°C oven to dry for 1.5 hours to cure the composite elastic material. Finally, after cooling to room temperature, the sample was removed from the cuvette to obtain the Ba sample of this embodiment. 0.79 Al 10.80 O 17.14 0.10Mn 2+ / PDMS green mechanoluminescent composite elastic material.

[0027] Example 2 In this embodiment, the green mechanoluminescent composite elastic material contains a green mechanoluminescent phosphor with the general chemical formula: Ba. 0.79 Al 10.75 O 17.14 : 0.15 Mn 2+ (i.e., x=0.15), the preparation method of this green mechanoluminescent composite elastic material includes the following steps: Step (1) According to the chemical formula Ba 0.79 Al 10.75 O 17.14 : 0.15 Mn 2+The stoichiometric ratios of the elements were accurately determined by weighing 3.95 mmol BaCO3 powder, 26.88 mmol Al2O3 powder, and 0.75 mmol MnCO3 powder. The BaCO3, Al2O3, and MnCO3 powders were ground and mixed thoroughly, then placed in an alumina crucible and pre-fired in a box furnace. The temperature was raised to 1000 °C and held for 4 hours. After natural cooling to room temperature, the mixture was discharged, ground into powder, and mixed evenly to obtain an intermediate. The intermediate was then pressed into disc-shaped pieces using a tablet press (pressure set to 15 MPa). These disc-shaped pieces were placed in a graphite crucible and then placed in a tube furnace with a mixed atmosphere of 20% H2-80% N2 (volume ratio). The temperature was raised to 1500 °C and held for 4 hours. After natural cooling to room temperature, the mixture was discharged, cooled, and ground into powder to obtain a high-purity green mechanoluminescent phosphor sample.

[0028] Step (2) Take the Ba obtained in step (1) 0.79 Al 10.75 O 17.14 : 0.15 Mn 2+ The green mechanoluminescent phosphor sample was mixed with PDMS colloid (Dow Corning SYLGARD 184 as the main agent in this embodiment) and curing agent (Dow Corning SYLGARD 184 as the curing agent in this embodiment) at a mass ratio of 2:2:0.2, with 1 g of phosphor as the reference. The well-mixed sample was transferred to a cuvette and then placed in an 80°C oven to dry for 0.5 h to cure the composite elastic material. Finally, after cooling to room temperature, the sample was removed from the cuvette to obtain the Ba of this embodiment. 0.79 Al 10.75 O 17.14 : 0.15 Mn 2+ / PDMS green mechanoluminescent composite elastic material.

[0029] Example 3 In this embodiment, the green mechanoluminescent composite elastic material contains a green mechanoluminescent phosphor with the general chemical formula: Ba. 0.79 Al 10.70 O 17.14 : 0.20 Mn 2+ (i.e., x=0.20), the preparation method of this green mechanoluminescent composite elastic material includes the following steps: Step (1), according to the chemical formula Ba 0.79 Al 10.70 O 17.14 : 0.20 Mn 2+The stoichiometric ratios of the elements were accurately measured as follows: 3.95 mmol BaCO3 powder, 26.75 mmol Al2O3 powder, and 1.00 mmol MnCO3 powder. The BaCO3, Al2O3, and MnCO3 powders were ground and mixed thoroughly, then placed in an alumina crucible and pre-fired in a box furnace. The temperature was raised to 900 °C and held for 5 hours. After natural cooling to room temperature, the mixture was discharged, ground into powder, and mixed evenly to obtain an intermediate. The intermediate was then pressed into disc-shaped pieces using a tablet press (pressure set to 14 MPa). These disc-shaped pieces were placed in a graphite crucible and then placed in a high-temperature tube furnace with a mixed atmosphere of 20% H2-80% N2 (volume ratio). The temperature was raised to 1400 °C and held for 5 hours. After natural cooling to room temperature, the mixture was discharged, cooled, and ground into powder to obtain a high-purity green mechanoluminescent phosphor sample.

[0030] Step (2): Take the Ba obtained in step (1) 0.79 Al 10.70 O 17.14 : 0.20 Mn 2+ The green mechanoluminescent phosphor sample was mixed with PDMS colloid (Dow Corning SYLGARD 184 as the main agent in this embodiment) and curing agent (Dow Corning SYLGARD 184 as the curing agent in this embodiment) at a mass ratio of 1.6:2:0.2, with 1 g of phosphor as the reference. The well-mixed sample was transferred to a cuvette and then dried in a 70 °C oven for 1.5 h to cure the composite elastic material. Finally, after cooling to room temperature, the sample was removed from the cuvette to obtain the Ba of this embodiment. 0.79 Al 10.70 O 17.14 : 0.20 Mn 2+ / PDMS green mechanoluminescent composite elastic material.

[0031] Example 4 In this embodiment, the green mechanoluminescent composite elastic material contains a green mechanoluminescent phosphor with the general chemical formula: Ba. 0.79 Al 10.65 O 17.14 : 0.25 Mn 2+ (i.e., x=0.25), the preparation method of this green mechanoluminescent composite elastic material includes the following steps: Step (1), according to the chemical formula Ba 0.79 Al 10.65 O 17.14 : 0.25 Mn 2+The stoichiometric ratios of the elements were accurately measured as follows: 3.95 mmol BaCO3 powder, 26.625 mmol Al2O3 powder, and 1.25 mmol MnCO3 powder. The BaCO3, Al2O3, and MnCO3 powders were ground and mixed thoroughly, then placed in an alumina crucible and pre-fired in a box furnace. The temperature was raised to 1000 °C and held for 4 hours. After natural cooling to room temperature, the mixture was discharged, ground into powder, and mixed evenly to obtain an intermediate. The intermediate was then pressed into disc-shaped pieces using a tablet press (pressure set to 15 MPa). These disc-shaped pieces were placed in a graphite crucible and then placed in a tube furnace with a mixed atmosphere of 20% H2-80% N2 (volume ratio). The temperature was raised to 1400 °C and held for 4 hours. After natural cooling to room temperature, the mixture was discharged, cooled, and ground into powder to obtain a high-purity green metronome phosphor sample.

[0032] Step (2): Take the Ba obtained in step (1) 0.79 Al 10.65 O 17.14 : 0.25 Mn 2+ The green mechanoluminescent phosphor sample was mixed with PDMS colloid (Dow Corning SYLGARD 184 as the main agent in this embodiment) and curing agent (Dow Corning SYLGARD 184 as the curing agent in this embodiment) at a mass ratio of 1:2:0.2, with 1 g of phosphor as the reference. The well-mixed sample was transferred to a cuvette and then placed in a 70 ℃ oven for 1 h to cure the composite elastic material. Finally, after cooling to room temperature, the sample was removed from the cuvette to obtain the Ba of this embodiment. 0.79 Al 10.65 O 17.14 : 0.25 Mn 2+ / PDMS green mechanoluminescent composite elastic material.

[0033] Example 5 In this embodiment, the green mechanoluminescent composite elastic material contains a green mechanoluminescent phosphor with the general chemical formula: Ba. 0.79 Al 10.60 O 17.14 : 0.30 Mn 2+ (i.e., x=0.30), the preparation method of this green mechanoluminescent composite elastic material includes the following steps: Step (1), according to the chemical formula Ba 0.79 Al 10.60 O 17.14 : 0.30 Mn 2+The stoichiometric ratios of the elements in the sample were determined by accurately weighing: 3.95 mmol BaCO3 powder, 26.5 mmol Al2O3 powder, and 1.50 mmol MnCO3 powder. The BaCO3, Al2O3, and MnCO3 powders were ground and mixed thoroughly, then placed in an alumina crucible and pre-fired in a box furnace. The temperature was raised to 1000 °C and held for 5 h. After natural cooling to room temperature, the mixture was discharged, ground into powder, and mixed evenly to obtain an intermediate. The intermediate was then pressed into disc-shaped pieces using a tablet press (pressure set to 13 MPa). These disc-shaped pieces were placed in a graphite crucible and then placed in a high-temperature tube furnace under a mixed atmosphere of 20% H2-80% N2 (volume ratio). The temperature was raised to 1500 °C and held for 4 h. After natural cooling to room temperature, the mixture was discharged, cooled, and ground into powder to obtain a high-purity green mechanoluminescent phosphor sample.

[0034] Step (2): Take the Ba obtained in step (1) 0.79 Al 10.60 O 17.14 : 0.30 Mn 2+ The green mechanoluminescent phosphor sample was mixed with PDMS colloid (Dow Corning SYLGARD 184 as the main agent in this embodiment) and curing agent (Dow Corning SYLGARD 184 as the curing agent in this embodiment) at a mass ratio of 1.3:2:0.2, with 1 g of phosphor as the reference. The well-mixed sample was transferred to a cuvette and then placed in an 80°C oven to dry for 1 hour to cure the composite elastic material. Finally, after cooling to room temperature, the sample was removed from the cuvette to obtain the Ba of this embodiment. 0.79 Al 10.60 O 17.14 : 0.30 Mn 2+ / PDMS green mechanoluminescent composite elastic material.

[0035] Example 6 In this embodiment, the green mechanoluminescent composite elastic material contains a green mechanoluminescent phosphor with the general chemical formula: Ba. 0.79 Al 10.55 O 17.14 : 0.35 Mn 2+ (i.e., x=0.35), the preparation method of this green mechanoluminescent composite elastic material includes the following steps: Step (1), according to the chemical formula Ba 0.79 Al 10.55 O 17.14 : 0.35 Mn 2+The stoichiometric ratios of the elements were accurately measured as follows: 3.95 mmol BaCO3 powder, 26.375 mmol Al2O3 powder, and 1.75 mmol MnCO3 powder. The BaCO3, Al2O3, and MnCO3 powders were ground and mixed thoroughly, then placed in an alumina crucible and pre-fired in a box furnace. The temperature was raised to 900 °C and held for 6 hours. After natural cooling to room temperature, the mixture was discharged, ground into powder, and mixed evenly to obtain an intermediate. The intermediate was then pressed into disc-shaped pieces using a tablet press (pressure set to 15 MPa). These disc-shaped pieces were placed in a graphite crucible and then placed in a high-temperature tube furnace under a mixed atmosphere of 20% H2-80% N2 (volume ratio). The temperature was raised to 1400 °C and held for 5 hours. After natural cooling to room temperature, the mixture was discharged, cooled, and ground into powder to obtain a high-purity green mechanoluminescent phosphor sample.

[0036] Step (2): Take the Ba obtained in step (1) 0.79 Al 10.55 O 17.14 : 0.35 Mn 2+ The green mechanoluminescent phosphor sample was mixed with PDMS colloid (Dow Corning SYLGARD 184 as the main agent in this embodiment) and curing agent (Dow Corning SYLGARD 184 as the curing agent in this embodiment) at a mass ratio of 1.8:2:0.2, with 1 g of phosphor as the reference. The well-mixed sample was transferred to a cuvette and then placed in a 70 ℃ oven for 2 h to cure the composite elastic material. Finally, after cooling to room temperature, the sample was removed from the cuvette to obtain the Ba of this embodiment. 0.79 Al 10.55 O 17.14 : 0.35 Mn 2+ / PDMS green mechanoluminescent composite elastic material.

[0037] Figure 1 The mechanoluminescent phosphor Ba prepared in Examples 1-6 0.79 Al 10.9-x O 17.14 :xMn 2+ XRD pattern. Figure 1 The XRD of all instances in the array can be compared with Ba. 0.79 Al 10.9 O 17.14 The PDF standard card (JCPDS 77-1522) showed good match. No obvious impurity peaks were detected, indicating that the prepared phosphor has high phase purity.

[0038] Figure 2 Ba prepared in Examples 1-6 0.79 Al10.9-x O 17.14 :xMn 2+ Mechanoluminescent spectra of the PDMS mechanoluminescent composite elastic materials under the same test conditions (3 Hz frequency and 50% tensile strain). The example mechanoluminescent composite elastic materials all exhibited bright green emission covering 450-650 nm, with the mechanoluminescence intensity increasing with Mn. 2+ The effect of increasing doping concentration first enhances and then weakens during mechanoluminescence of Mn. 2+ The optimal doping content is x=0.25.

[0039] Figure 3 Ba prepared in Example 4 0.79 Al 10.65 O 17.14 0.25Mn 2+ / Spectral diagrams of PDMS composite elastic materials under different tensile strains. As the tensile strain in the tensile testing machine increases from 40% to 120%, Ba... 0.79 Al 10.65 O 17.14 0.25Mn 2+ The mechanoluminescence intensity of the PDMS composite elastic material is enhanced by 9.3 times, exhibiting excellent strain properties.

[0040] Figure 4 This is a fitting graph of the mechanoluminescence intensity of the composite elastic material prepared in Example 4 under different tensile strains. Ba 0.79 Al 10.65 O 17.14 0.25Mn 2+ The mechanoluminescence intensity of PDMS composite elastic material follows a linear relationship with the tensile strain of a tensile testing machine (i.e., y = -15919.2 + 498.12x). This property enables stress luminescence to meet the needs of various scenarios, and has great application potential in fields such as tensile sensing, health monitoring of engineering structures, anti-counterfeiting technology, and biomedicine.

[0041] Figure 5 Ba prepared in Example 4 0.79 Al 10.65 O 17.14 0.25Mn 2+ Repeatability test results of PDMS composite elastic material at 50% tensile strain and 3 Hz frequency. After undergoing more than 15,000 repeated mechanical stretching cycles, the composite elastic material still maintains a stable green emission with half of its initial strength.

[0042] Figure 6 To prepare Ba in Example 4 0.79 Al 10.65 O 17.14 0.25Mn2+ A PDMS composite elastic material is fixed to a table with transparent tape. One person writes on the film (i.e., the transparent tape), while another person uses time-lapse photography to record photos of the handwriting. Figure 6 The written "XAUAT" lettering is clearly visible, and the writing trajectory and pressure level can be visually mapped to different luminescence intensities and colors. This demonstrates the effectiveness of the prepared Ba... 0.79 Al 10.65 O 17.14 0.25Mn 2+ PDMS composite elastic materials have great potential in applications such as electronic signatures and anti-counterfeiting.

[0043] In summary, the preparation method of the green mechanoluminescent composite elastic material prepared by this invention is simple and can exhibit bright green luminescence under various forces. Under conditions of 3 Hz frequency and 50% tensile strain, the composite material maintains stable green luminescence even after 15,000 repeated mechanical stretching cycles. This green mechanoluminescent composite elastic material exhibits excellent repeatability and cyclic stability, effectively broadening its application range.

[0044] By writing the character "XAUAT" on the prepared composite elastic material, the writing and pressure levels can be visually mapped to different luminescence intensities and colors. This demonstrates the significant potential of the prepared mechanoluminescent material in applications such as electronic signatures and anti-counterfeiting.

[0045] The above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Those skilled in the art can make modifications and improvements based on the technical solutions of the present invention, but such modifications and improvements do not depart from the essential scope of the embodiments of the present invention and all fall within the protection scope of the technical solutions of the present invention.

Claims

1. A green mechanoluminescent composite elastic material, characterized in that, It includes an elastic matrix and a green mechanoluminescent phosphor dispersed in the elastic matrix; the general chemical formula of the green mechanoluminescent phosphor is: Ba 0.79 Al 10.9-x O 17.14 :xMn 2+ , where 0 < x ≤ 0.

35.

2. The green mechanoluminescent composite elastic material according to claim 1, characterized in that, The elastic matrix is ​​a polydimethylsiloxane elastic matrix.

3. The method for preparing a green mechanoluminescent composite elastic material according to claim 1 or 2, characterized in that, The process includes the following: The green mechanoluminescent phosphor is mixed with the raw materials of the elastic matrix and then cured to obtain the green mechanoluminescent composite elastic material.

4. The method for preparing a green mechanoluminescent composite elastic material according to claim 3, characterized in that, The preparation process of the green mechanoluminescent phosphor includes: The raw material powder of green metronome phosphor is mixed evenly to obtain a raw material mixture; The raw material mixture was pre-calcined at 800-1000℃ for 4-6 hours. After pre-calcination, it was cooled to room temperature, then ground into powder and mixed to obtain an intermediate. The intermediate is pressed into a sheet-like molded body; The sheet-shaped body was calcined in a reducing atmosphere at 1300–1500°C for 4–6 h. After calcination, it was naturally cooled to room temperature and ground into powder to obtain the green mechanoluminescent phosphor.

5. The method for preparing a green mechanoluminescent composite elastic material according to claim 4, characterized in that, The raw material for the green mechanoluminescent phosphor is a compound powder containing Ba, Al, O and Mn elements.

6. A method for preparing a green mechanoluminescent composite elastic material according to claim 4 or 5, characterized in that, The raw materials for the green phosphor are BaCO3 powder, Al2O3 powder and MnCO3 powder.

7. The method for preparing a green mechanoluminescent composite elastic material according to claim 4, characterized in that, When the intermediate is pressed into a sheet, the pressure used during the pressing process is 13 to 15 MPa.

8. The method for preparing a green mechanoluminescent composite elastic material according to claim 4, characterized in that, The reducing atmosphere is a mixture of hydrogen and an inert gas, wherein the volume fraction of H2 is 10% to 20%.

9. The method for preparing a green mechanoluminescent composite elastic material according to claim 8, characterized in that, The inert gas includes at least one of nitrogen and helium.

10. The method for preparing a green mechanoluminescent composite elastic material according to claim 3, characterized in that, The raw materials of the elastic matrix include polydimethylsiloxane and a curing agent, and the mass ratio of the green mechanoluminescent phosphor, polydimethylsiloxane and curing agent is (1-2):(1.9-2.1):(0.18-0.22). During curing, the curing temperature is 70–80 ℃ and the curing time is 0.5–2 h.

Images