A water speed sensor and a method of manufacturing the same

Abstract

This invention proposes a water velocity sensor and its fabrication method. The water velocity sensor includes a stress-luminescent thin film, which comprises an elastic polymer carrier doped with a stress-luminescent material. Based on the stress-luminescent material, this water velocity sensor emits light directly under external mechanical force without requiring an additional power source. Using an elastic polymer as a carrier to form a thin-film device, it not only allows for quantitative analysis of water velocity through luminescence intensity but also enables visual judgment of water velocity. Furthermore, it can be remotely collected via a spatial optical path or optical fiber, achieving self-powered, remote, non-contact water velocity sensing.

Description

Technical Field

[0001] This invention relates to the field of water velocity sensor technology, and in particular to a water velocity sensor and its preparation method. Background Technology

[0002] Existing water velocity sensors primarily measure flow velocity through the Hall effect, requiring an external power supply. Stress-luminescent materials, under various mechanical stimuli such as tension, compression, friction, and impact fracture, can achieve instantaneous response through photon emission, showing broad application prospects in stress sensing, electronic signature systems, optical anti-counterfeiting, self-powered displays, and lighting; however, the application of stress-luminescent materials to water velocity sensors has not yet been explored. Summary of the Invention

[0003] This invention proposes a water velocity sensor and its preparation method. Based on stress-luminescent materials, it does not require an additional power supply. It can not only quantitatively analyze the water velocity through luminescence intensity, but also realize the visual judgment of the water velocity, and has a remote non-contact sensing function.

[0004] The technical solution of the present invention is implemented as follows: a water velocity sensor includes a stress-luminescent thin film, the stress-luminescent thin film includes an elastic polymer carrier, and the elastic polymer carrier is doped with stress-luminescent material.

[0005] Furthermore, the stress-luminescent material is a micron-sized stress-luminescent powder.

[0006] Furthermore, nanoparticles are attached to the stress-luminescent powder, and the Mohs hardness of the nanoparticles is greater than that of the stress-luminescent powder. Under the premise of the same particle size, the greater the hardness, the better the luminescent performance of the stress-luminescent material. Using 100nm nanodiamonds (NDs) yields better results than 100nm alumina nanoparticles, which in turn yield better results than 100nm calcium carbonate nanoparticles. The nanoparticles can be spherical, plate-like, ellipsoidal, conical, or have various irregular morphologies.

[0007] Furthermore, the nanoparticles are attached to the stress luminescent powder via amide bonds.

[0008] Furthermore, the nanoparticles are one or more of diamond, alumina, silicon dioxide, calcium carbonate, zinc oxide, and zirconium oxide.

[0009] Furthermore, the stress-emitting phosphors are ZnS:Cu, ZnS:Mn, CaZnSOS:Bi,Li, and Sr3Al2O5Cl2:Eu. 2+ Sr3Al2O5Cl2:Tb 3+ Sr3Al2O5Cl2:Ce 3+ Ba2Ga2GeO7:Pr 3+ Er 3+CaAl2O4:Eu 2+ ,Sm 3+ Sr3Al2O6:Eu, CaZnGe2O6 / Mn 2+ CaLaAl3O7:Tb 3+ MgF2:Mn 2+ and ZnB2O4:Mn 2+ Any one or more of the following.

[0010] Furthermore, the elastic polymer is PDMS.

[0011] A method for fabricating a water velocity sensor includes the following steps:

[0012] (1) Add stress-luminescent material to the elastic polymer precursor liquid and stir evenly to obtain stress-luminescent mixed slurry;

[0013] (2) Apply the stress-luminescent mixed paste from step (1) evenly onto the substrate, and heat it to cure to form a stress-luminescent film; the substrate can be an acrylic plate, glass plate, PET film or silicone plate.

[0014] (3) The stress-emitting thin film from step (2) is used as the water velocity sensing part and fixed on the hollow bracket to form a water velocity sensor.

[0015] Further, in step (1), the weight ratio of the elastic polymer precursor liquid to the stress luminescent material is 1:(0.1-2.4).

[0016] Further, in step (2), the above-mentioned stress luminescent mixed slurry is evenly distributed on the substrate using a spin coater or a scraper coater. The spin coater speed is 200-1500 rad / min; the thickness of the stress luminescent film is 100-3000 μm; and the curing temperature is 60-120℃.

[0017] Furthermore, the preparation method of the stress-luminescent material is as follows:

[0018] 1) Amination treatment of micron-sized stress luminescent powder;

[0019] 2) Carboxylating the nanoparticles;

[0020] 3) The stress luminescent material is obtained by dehydration condensation reaction of aminated stress luminescent powder and carboxylated nanoparticles.

[0021] Furthermore, in step 1), the specific method for the amination treatment of the stress-induced luminescent powder is as follows:

[0022] Disperse 1-5g of stress luminescent powder in 20mL of ethanol solvent, then add 70-220μL of 3-aminopropyltriethoxysilane (APTES), stir for 2min, then add 210-660μL of deionized water, stir for more than 2h, then wash three times with deionized water, and dry to obtain amination-modified stress luminescent powder.

[0023] Furthermore, in step 3), the specific method for the dehydration condensation reaction is as follows:

[0024] 0.001-0.005 g of carboxylated nanoparticles were dispersed in 30 mL of morpholine ethanesulfonic acid buffer (MES), followed by the addition of 0.01 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and 0.02 g of N-hydroxythiosuccinimide sodium salt (NHS). The mixture was stirred, centrifuged, and the precipitate was collected. The precipitate was then dispersed in 20 mL of deionized water (pH = 7), and 1-5 g of aminated stress luminescent powder was added. The mixture was stirred for 12 h to obtain a stress luminescent material with a micro-nano structure.

[0025] Furthermore, the concentration of the morpholine ethanesulfonic acid buffer was 0.1M (M is an abbreviation for mol / L), and the pH was 6.0.

[0026] Furthermore, the diameter of the nanoparticles is 50-1000 nm, and the diameter of the stress luminescent powder is 10-50 μm.

[0027] Furthermore, the stress luminescent material obtained has the strongest stress luminescence intensity when the diameter ratio of the stress luminescent powder to the nanoparticles is 240 and the mass ratio is 400.

[0028] The beneficial effects of this invention are:

[0029] This invention involves encapsulating a stress-luminescent material within an elastic polymer to obtain a stress-luminescent thin film, which is then fixed onto a perforated support to form a water velocity sensor. Utilizing the property of the stress-luminescent material to emit light under external stress, this device responds to water velocity without requiring an external power source. It not only allows for quantitative analysis of water velocity through luminescence intensity but also enables visual judgment of water velocity. Remote collection can be achieved via spatial optical paths or optical fibers, realizing self-powered remote non-contact water velocity sensing. Compared to traditional water velocity sensors that require battery or power supply, this stress-luminescent material-based water velocity sensor achieves water velocity detection with zero energy consumption and is safe and environmentally friendly.

[0030] This invention modifies nanoparticles on the surface of stress luminescent powder with amide bonds to form a stress luminescent material with a micro-nano structure, which has better stress luminescence effect and good stress luminescence stability; the introduction of high-hardness nanoparticles improves the stress transmission efficiency of the stress luminescent material, making the luminescence intensity of the stress luminescent material much stronger than that of the stress luminescent powder. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A flowchart for testing the luminous intensity of a water velocity sensor;

[0033] Figure 2 The light intensity spectrum of the water velocity sensor under different water velocities in Example 1;

[0034] Figure 3 The image shows the luminescence intensity of the water velocity sensor under different water velocity stimuli in Example 1.

[0035] Figure 4 Example 2 shows the luminous intensity curves of the water velocity sensor under different water velocities;

[0036] Figure 5 The stress emission curves of the stress-emitting materials in Examples 2, 5, and 6 are shown.

[0037] Figure 6 The stress emission curves of the stress-emitting materials in Examples 2, 3, and 4 are shown.

[0038] Figure 7 The image shows the stress luminescence stability test result of the stress-luminescent material prepared in Example 2.

[0039] Figure 8 The stress emission curves are for the stress-luminescent materials prepared in Example 2 and Comparative Example 1. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1

[0042] A water velocity sensor includes a stress-luminescent thin film, which comprises an elastic polymer carrier doped with a stress-luminescent material. The stress-luminescent material is a micron-sized stress-luminescent powder. The stress-luminescent powder is ZnS:Cu, with a diameter of 24 μm, and the elastic polymer is PDMS.

[0043] A method for fabricating a water velocity sensor includes the following steps:

[0044] (1) Add stress-luminescent material to the elastic polymer precursor liquid and stir evenly to obtain stress-luminescent mixed slurry;

[0045] (2) Apply the stress-luminescent mixed paste from step (1) evenly onto the substrate, and heat it to cure to form a stress-luminescent film;

[0046] (3) The stress-emitting thin film from step (2) is used as the water velocity sensing part and fixed on the hollow bracket to form a water velocity sensor.

[0047] In step (1), the preparation method of the elastic polymer precursor liquid is as follows:

[0048] The PDMS prepolymer and curing agent were mixed and stirred evenly at a mass ratio of 9:1 to form a PDMS precursor solution. Air bubbles were removed by standing or using a vacuum pump. The standing time was 4 hours, and the vacuum pump extraction time was 30 minutes.

[0049] In step (1), the preparation method of the stress luminescent powder mixed slurry is as follows:

[0050] The mass ratio of PDMS precursor solution to stress luminescent powder is 1:0.7. Stress luminescent powder is added to the PDMS precursor solution and stirred evenly to obtain a stress luminescent mixture of stress luminescent powder and PDMS. Air bubbles are removed by standing or using a vacuum pump. The standing time is 4 hours, and the vacuum pump extraction time is 30 minutes.

[0051] In step (2), the method for preparing the stress-luminescent thin film is as follows:

[0052] like Figure 1 As shown, the stress-luminescent mixed slurry was dripped onto an acrylic plate and then coated using a spin coater or a scraper coater to ensure the slurry was evenly distributed across the entire acrylic plate. The spin coater was operated at a speed of 500 rad / min. The acrylic plate coated with the stress-luminescent mixed slurry was then placed in a forced-air drying oven at 80°C for 2 hours. After cooling, the stress-luminescent film was peeled off the acrylic plate, yielding a 5cm × 5cm square stress-luminescent film with a thickness of 280μm.

[0053] In step (3), the fabrication method of the water velocity sensor based on stress-luminescent materials is as follows:

[0054] The stress-emitting film was cut into a 5cm×2cm rectangular film using a metal cutting tool, and then fixed onto a hollowed-out rectangular acrylic mold to form a water velocity sensor.

[0055] The luminescence intensity of the water velocity sensor prepared in Example 1 was tested, and the testing procedure is as follows: Figure 2 As shown. Figure 3 The light intensity curves of the water velocity sensor at different water velocities are obtained from... Figure 3 It can be seen that the light intensity is positively correlated with the water velocity, and the water velocity can be distinguished by the change in light intensity.

[0056] Figure 4 This is a graph showing the luminescence intensity of a water velocity sensor under different water velocity stimuli. It can be seen that as the water velocity increases, the luminescence intensity of the water velocity sensor based on stress-luminescent material becomes stronger.

[0057] Example 2

[0058] This embodiment is basically the same as Embodiment 1, except that: the stress-luminescent material is a micron-sized stress-luminescent powder, and nanoparticles are attached to the stress-luminescent powder via amide bonds. The Mohs hardness of the nanoparticles is greater than that of the stress-luminescent powder. The stress-luminescent powder is ZnS:Cu, the elastic polymer is PDMS, and the nanoparticles are 100nm diameter nanodiamonds (NDs).

[0059] The method for preparing stress-luminescent materials includes the following steps:

[0060] 1) Amination treatment of stress luminescent powder

[0061] 1g of stress luminescent powder ZnS:Cu was dispersed in 20mL of ethanol and stirred for 10-30min. Then, 70μL of APTES was added and stirred for 2min. Next, 210μL of deionized water was added and stirred for 2h to allow APTES to be fully hydrolyzed. The supernatant was removed by centrifugation, and the precipitate was washed three times with deionized water. Then, it was placed in a forced-air drying oven to dry and obtain amination-modified stress luminescent powder.

[0062] 2) Carboxylation treatment of nanoparticles

[0063] 0.5 g of nanodiamonds (NDs) were placed in a muffle furnace and kept at 450 °C for 5 h. After cooling, they were immersed in 90 mL of a strong acid solution (H₂SO₄:HNO₃ = 3:1, vol / vol) and stirred with a magnetic stirrer at 80 °C for 24 h. The precipitate was then collected by centrifugation. The precipitate was placed in 100 mL of NaOH aqueous solution (0.1 M) and stirred at 100 °C for 1 h. After centrifugation, the precipitate was obtained again. The precipitate was then placed in 100 mL of HCl aqueous solution (0.1 M) and stirred at 100 °C for 1 h. Finally, the precipitate was washed three times with deionized water and dried in a forced-air drying oven to obtain carboxylated NDs with a size of 100 nm.

[0064] 3) Dehydration condensation reaction of aminated stress luminescent powder and carboxylated nanoparticles.

[0065] 0.0025 g of carboxylated NDs was dispersed in 30 mL of MES buffer (0.1 M, pH = 6.0), 0.01 g of EDC and 0.02 g of NHS were added and stirred for 20 min. After centrifugation, the precipitate was collected and dispersed in 20 mL of deionized water (pH = 7). 1 g of aminated stress luminescent powder was added and stirred for 12 h to obtain stress luminescent material (ZnS:Cu / NDs).

[0066] Example 3

[0067] This embodiment is basically the same as embodiment 2, except that the mass of carboxylated NDs in step (3) is 0.0015g.

[0068] Example 4

[0069] This embodiment is basically the same as embodiment 2, except that the mass of carboxylated NDs in step (3) is 0.004g.

[0070] Example 5

[0071] This embodiment is basically the same as embodiment 2, except that the size of NDs in step (2) is 300nm.

[0072] Example 6

[0073] This embodiment is basically the same as embodiment 2, except that the size of NDs in step (2) is 1000nm.

[0074] Figure 5 The figures show the stress luminescence curves of the stress luminescent materials prepared in Examples 2, 5, and 6. It can be seen that the luminescence intensity of the stress luminescent material with introduced NDs is stronger than that of the stress luminescent powder without modified NDs. Moreover, it can be seen that as the size of NDs decreases, the luminescence intensity enhancement factor increases.

[0075] Figure 6 The stress emission curves of the stress-emitting materials prepared in Examples 2, 3, and 4 show that the optimal concentration of carboxylated NDs is 0.25%.

[0076] Figure 7 The image shows the stress luminescence stability test result of the stress-luminescent material prepared in Example 2. The luminescence intensity of the composite material remained stable after 8000 stress cycles, indicating that the composite material has high stability.

[0077] Comparative Example 1

[0078] 0.0025g of NDs was uniformly dispersed in 20mL of ethanol solvent and sonicated for half an hour. Then, 1g of stress luminescent powder was added to the beaker and stirred on a magnetic stirrer at a speed of 500rad / min until the solvent was completely evaporated to obtain mechanically mixed stress luminescent material with a diameter of 100nm.

[0079] Figure 8 The stress luminescence curves of the stress luminescent materials prepared in Example 2 and Comparative Example 1 are shown. By conducting stress luminescence tests on the stress luminescent materials obtained by mechanically mixing ZnS:Cu with 100nm NDs and by linking them through amide bonds, it was found that the stress luminescent materials linked by chemical bonds have better stress luminescence effects than the mechanically mixed stress luminescent materials.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water velocity sensor, characterized in that: It is prepared according to the following steps: (1) Add stress-luminescent material to the elastic polymer precursor liquid and stir evenly to obtain stress-luminescent mixed slurry; (2) Apply the stress-luminescent mixed paste from step (1) evenly to the substrate, and heat it to cure to form a stress-luminescent film; (3) The stress-emitting thin film from step (2) is used as the water velocity sensing part and fixed on the hollow bracket to form a water velocity sensor; The preparation method of stress-luminescent materials is as follows: 1) Amination treatment of micron-sized stress luminescent powder; 2) Carboxylating the nanoparticles; 3) By dehydration condensation reaction, aminated stress luminescent powder and carboxylated nanoparticles are combined to obtain stress luminescent materials.

2. A water velocity sensor according to claim 1, characterized in that, In step 1), the specific method for amination of stress luminescent powder is as follows: 1-5g of stress luminescent powder is dispersed in 20 mL of ethanol solvent, then 70-220 mL of 3-aminopropyltriethoxysilane is added, and after stirring, 210-660 mL of deionized water is added and stirred for more than 2 hours. Then, the powder is washed three times with deionized water and dried to obtain amination of stress luminescent powder.

3. A water velocity sensor according to claim 1 or 2, characterized in that, The stress-luminescent thin film includes an elastic polymer carrier, and the elastic polymer carrier is doped with stress-luminescent material.

4. The water velocity sensor according to claim 3, characterized in that, The stress-luminescent material is a micron-sized stress-luminescent powder.

5. The water velocity sensor according to claim 4, characterized in that, The stress-emitting powder has nanoparticles attached to it, and the Mohs hardness of the nanoparticles is greater than that of the stress-emitting powder.

6. The water velocity sensor according to claim 5, characterized in that, Nanoparticles are attached to stress luminescent powder via amide bonds.

7. The water velocity sensor according to claim 6, characterized in that, The nanoparticles are one or more of the following: diamond, alumina, silicon dioxide, calcium carbonate, zinc oxide, and zirconium oxide.

8. The water velocity sensor according to claim 3, characterized in that, Stress-induced luminescent powders include ZnS:Cu, ZnS:Mn, CaZnS:Bi,Li, and Sr3Al2O5Cl2:Eu. 2+ Sr3Al2O5Cl2:Tb 3+ Sr3Al2O5Cl2:Ce 3+ Ba2Ga2GeO7: Pr 3+ Er 3+ CaAl2O4:Eu 2+ ,Sm 3+ Sr3Al2O6:Eu, CaZnGe2O6 / Mn 2+ CaLaAl3O7:Tb 3+ MgF2:Mn 2+ and ZnB2O4:Mn 2+ Any one or more of the following.

9. The water velocity sensor according to claim 3, characterized in that, The elastic polymer is PDMS.

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