Platinum supported tungsten trioxide doped hydro-acid hydrogen-induced color change material, preparation method and application thereof

Abstract

The present application relates to a platinum-loaded tungsten trioxide doped aqueous hydrogen-induced photochromic material, a preparation method thereof and an application thereof, the preparation method comprising the following steps: preparing an initiator aqueous solution; preparing an emulsifier aqueous solution; preparing an acrylic acid emulsion by using an acrylic acid monomer, the initiator aqueous solution and the emulsifier aqueous solution; preparing a Pt / WO3 composite nanorod material by using a WO3 nanorod material, ethylene glycol, platinum chlorohydrate and deionized water; adding the Pt / WO3 composite nanorod material into the acrylic acid emulsion, and filtering the mixture to obtain a hydrogen-induced photochromic material. The hydrogen-induced photochromic material is prepared by using the preparation method. The application is the application of the hydrogen-induced photochromic material in hydrogen leakage detection. The preparation method is simple in process and low in cost, the prepared hydrogen-induced photochromic material can obviously change color when being subjected to gas-induced photochromism, has short response time, high sensitivity, strong adhesion, good flexibility and environmental protection.

Description

Technical Field

[0001] This invention relates to platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic materials, their preparation methods, and applications, belonging to the field of hydrogen-sensitive materials technology. Background Technology

[0002] As the global energy structure transitions towards cleaner and lower-carbon energy, hydrogen, as an abundant, high-calorific-value, and zero-carbon-emission secondary energy source, has shown enormous application potential in fuel cell vehicles, aerospace, chemical refining, and distributed energy. However, hydrogen itself is colorless and odorless, with a small molecular weight and high diffusion coefficient, making it highly susceptible to leakage even through tiny gaps. Hydrogen has an extremely wide flammability range in air (4%-75% by volume), and once it accumulates to its explosive limit in a confined or semi-confined space, it is highly likely to ignite or even explode upon contact with an open flame or high heat, posing a significant safety risk. Therefore, developing efficient, reliable, and real-time hydrogen leak detection technology is a crucial prerequisite for ensuring the safe and stable operation of all aspects of the hydrogen energy industry chain.

[0003] Currently, commonly used hydrogen detection technologies mainly include point sensors based on physical or electrochemical principles (such as catalytic combustion, electrochemical, and semiconductor sensors) and infrared imagers. While these technologies are mature and widely used, they still have the following limitations: point sensors require a deployment of sensors, which may miss leaks in uncovered areas, and they typically require power and signal cables, making installation and maintenance complex and costly; infrared imagers are expensive and sometimes lack sufficient sensitivity for operating environments and small-flow leaks. Therefore, the industry urgently needs a passive leak monitoring solution that can achieve large-area, low-cost, visualized detection without requiring external power.

[0004] Color-changing chemical indicator technology offers an innovative approach. This type of technology typically utilizes hydrogen gas, under the action of a specific catalyst, to undergo a reduction reaction with metal oxides (such as molybdenum dioxide and tungsten trioxide), causing reversible or irreversible changes in their optical properties (such as light absorption or reflection characteristics), resulting in a visible color change. Integrating such hydrogen-sensitive materials into coatings or adhesive systems can create "smart" coatings or tapes that can be directly applied to high-risk areas such as pipe joints, valves, and tank welds. In the event of a hydrogen leak, the material at the contact point will rapidly change color, accurately locating the leak and providing all-weather, comprehensive safety warnings.

[0005] However, the practical application of hydrogen-sensitive color-changing technology, especially the development of water-based products, still faces multiple challenges: hydrogen-sensitive metal oxide nanoparticles are prone to agglomeration and sedimentation in water-based systems, affecting the storage stability of coatings and the uniformity and sensitivity of the final film. Hydrogen-sensitive materials need to be exposed to the coating surface to contact hydrogen gas, but exposed nanoparticles are easily deactivated or undergo non-specific color changes due to the influence of water vapor, oxygen, and acidic or alkaline substances in the environment, resulting in slow response speed, decreased sensitivity, or shortened service life. As a functional coating or tape, it needs to possess good adhesion, flexibility, abrasion resistance, and weather resistance to adapt to the complex physical and chemical environments of industrial sites. Solvent-based systems pose safety and environmental protection issues such as VOC emissions and flammability. Developing high-performance water-based systems aligns with the development trend of green chemistry and is more convenient for on-site construction and maintenance.

[0006] Existing hydrogen-sensitive color-changing coatings or films mainly focus on the color-changing mechanism of the material itself, or adopt solvent-based systems, physical vapor deposition and other processes. They are still insufficient in solving the comprehensive engineering problems of the above-mentioned water-based applications. Summary of the Invention

[0007] To overcome the above-mentioned defects of the prior art, the present invention provides a platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material, its preparation method and application. The preparation method is simple and low in cost. The prepared hydrochromic material can undergo obvious color changes when gas is chromatic, with short response time, high sensitivity, strong adhesion, good flexibility and environmental protection.

[0008] The technical solution adopted in this invention is: a method for preparing platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material, comprising the following steps: S1: Mix the initiator with deionized water until homogeneous to obtain an initiator aqueous solution; S2: Mix the emulsifier, Triton-100 and deionized water evenly to obtain an emulsifier aqueous solution; S3: Add acrylic monomer to the emulsifier aqueous solution and stir evenly to obtain a pre-emulsified mixed monomer; S4: Add a portion of the pre-emulsified mixed monomers to the initiator aqueous solution, and then add a certain amount of initiator aqueous solution (the initiator aqueous solution with the same solute as the initiator aqueous solution prepared in S1) and stir until the liquid has a bluish tint; S5: Add the remaining pre-emulsified mixed monomers dropwise to the solution in S4 to obtain an acrylic emulsion; S6: Mix WO3 nanorod material, ethylene glycol, platinum chlorate hexahydrate and deionized water evenly and react them. After the reaction is complete, filter, wash and dry the product to obtain Pt / WO3 composite nanorod material. S7: Pt / WO3 composite nanorods were added to the acrylic emulsion, mixed evenly, and then filtered to obtain platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material.

[0009] Preferably, in S1, the mass ratio between the initiator and deionized water is 1:120 to 1:80.

[0010] Furthermore, the mass ratio of the initiator to deionized water is 1:100.

[0011] Preferably, the initiator in S1 is at least one selected from ammonium persulfate, azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, potassium persulfate, and sodium persulfate.

[0012] Preferably, the reaction conditions in S1 are: heating to 80°C under nitrogen protection and stirring under reflux.

[0013] Preferably, in S2, the mass ratio of emulsifier, Triton-100 and deionized water is 4:3:25 to 4:3:15.

[0014] Furthermore, the mass ratio of emulsifier, Triton-100, and deionized water is 4:3:20.

[0015] Preferably, the emulsifier is at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and allyloxyhydroxypropyl sulfonate.

[0016] Preferably, the reaction conditions in step S2 are stirring at room temperature.

[0017] Preferably, in S3, the mass ratio between the acrylic monomer and the emulsifier aqueous solution is 10:1 to 20:1.

[0018] Furthermore, the mass ratio between the acrylic monomer and the emulsifier aqueous solution is 20:1.

[0019] Preferably, the acrylic monomer is at least three of the following: acrylic acid, methyl methacrylate, isooctyl acrylate, ethyl acrylate, hydroxyethyl acrylate, and butyl acrylate.

[0020] Furthermore, the acrylic monomers include butyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, and isooctyl acrylate, with a mass ratio of butyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, and isooctyl acrylate of 2:1:1:4:12.

[0021] Preferably, in S4, the mass of the pre-emulsified mixed monomer added to the initiator aqueous solution is 10% of the mass of the pre-emulsified mixed monomer prepared in S3.

[0022] Preferably, in step S4, the initiator mass fraction of the initiator aqueous solution added again is 5%.

[0023] Preferably, the pH value of the acrylic emulsion in S5 is 6-8, which can be adjusted using an aqueous sodium bicarbonate solution.

[0024] Preferably, in step S6, the mass ratio of WO3 nanorod material, ethylene glycol, platinum chlorate hexahydrate and deionized water is 9:36:0.17:200.

[0025] Preferably, the reaction temperature in S6 is 150℃~190℃, the reaction time is 5h, the drying temperature is 80℃, and the drying time is 12h.

[0026] Preferably, in step S7, the amount of Pt / WO3 composite nanorod material added is 2% to 6% of the mass of the acrylic emulsion.

[0027] The platinum-supported tungsten trioxide-doped aqueous acrylate hydrochromic material is prepared using any of the preparation methods for platinum-supported tungsten trioxide-doped aqueous acrylate hydrochromic materials disclosed in this invention.

[0028] Preferably, the amount of Pt / WO3 composite nanorods added to the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material is 2% to 6% of the total mass of the hydrochromic material.

[0029] Furthermore, the amount of Pt / WO3 composite nanorods added to the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material is 6% of the total mass of the hydrochromic material.

[0030] The application of platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material prepared by any of the preparation methods of platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material disclosed in this invention, or any of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic materials disclosed in this invention, in hydrogen leak detection.

[0031] Preferably, a platinum-loaded tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material is coated onto a BOPP film, and PET is used as a release film to prepare a hydrogen-sensitive color-changing tape.

[0032] Preferably, the coating thickness of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material is 0.2 mm to 0.5 mm.

[0033] Furthermore, the coating thickness of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material is 0.2 mm.

[0034] The beneficial effects of this invention are: (1) This invention achieves highly stable and uniform dispersion of hydrogen-sensitive color-changing nanoparticles in water-based acrylic resin. Through innovative formulation and preparation process, while ensuring excellent adhesion, flexibility and durability of the coating, the hydrogen-sensitive color-changing material can efficiently and quickly make a significant color response to hydrogen leakage.

[0035] (2) This invention prepares an aqueous acrylic emulsion through semi-continuous emulsion polymerization and introduces platinum-supported tungsten trioxide nanopowder as a hydrogen-sensitive component. The prepared hydrogen-chromic material can undergo rapid and obvious color changes under hydrogen leakage conditions, and has the advantages of short response time, high sensitivity, strong adhesion, good flexibility, and environmental protection with no VOC emissions. The fast response and high sensitivity are mainly due to the fine control of the latex particle structure by semi-continuous emulsion polymerization. The latex particles prepared by this process have small particle size (50~150nm) and uniform distribution, and large specific surface area, so that Pt / WO3 nanoparticles can be distributed more on the surface of the latex particles rather than inside, which greatly shortens the contact path between hydrogen and active sites. At the same time, the core-shell structure enriches the functional groups containing carboxyl and hydroxyl groups in the shell layer, providing sufficient anchoring points for Pt / WO3, ensuring uniform response of the entire coating, thereby achieving rapid color development in a few seconds and a detection sensitivity as low as 0.1%. The good adhesion is due to the fact that the polar groups such as ester and carboxyl groups on the acrylic resin chain can form hydrogen bonds and dipole interactions with the surfaces of substrates such as metals and glass. Furthermore, the semi-continuous polymerization enriches these groups on the outer layer of the latex particles, allowing the film to directly adhere to the substrate after formation, resulting in a stronger anchoring effect. The good flexibility is achieved by adjusting the ratio of hard and soft monomers (such as by adding butyl acrylate) to lower the glass transition temperature of the resin below room temperature and form a moderately cross-linked network. Simultaneously, the semi-continuous process avoids uneven composition of chain segments during polymerization, ensuring that the coating film does not experience localized cracking during bending or impact, maintaining good overall elasticity.

[0036] (3) The core function of Pt in this invention is as a catalyst for hydrogen dissociation, and it enables WO3 to rapidly develop color at room temperature by means of the hydrogen spillover effect. Pt is loaded on the surface of WO3 in the form of tiny crystals of 2~5nm. Its special electronic structure can firmly grasp hydrogen molecules and significantly weaken the HH bond, so that hydrogen dissociates rapidly on the Pt surface into two active hydrogen atoms (H2O2, H ... This step reduces the reaction, which originally required high temperatures, to occur at room temperature. Subsequently, these hydrogen atoms do not remain on the Pt, but instead automatically "flow" into the adjacent WO3 lattice through the hydrogen spillover effect, injecting themselves as protons and electrons—the electrons carrying the W atoms from the WO3 lattice... 6+ Restore to W 5+ Protons are embedded in the interstitial spaces of the crystal lattice, forming deep blue tungsten bronze (H). xThe material's color changes from light yellow / gray to dark blue, a change clearly visible to the naked eye. This series of "dissociation-overflow-color change" processes forms an accelerated cycle, with a response speed far faster than that of a pure WO3 system without Pt.

[0037] (4) This invention solves the problem of easy aggregation and sedimentation of hydrogen-sensitive metal oxide nanoparticles in aqueous systems through a triple guarantee of "steric hindrance as the main factor, electrostatic repulsion as a supplement, and ultrasonic dispersion as the final safeguard". First, the carboxyl groups (-COOH) and hydroxyl groups (-OH) on the molecular chain of the aqueous acrylic resin can be adsorbed on the surface of Pt / WO3 particles like "hands" to form a layer of polymer molecular brush. When two particles approach each other, this brush generates a strong repulsive force, preventing them from sticking together due to van der Waals forces. This is the most critical stabilization mechanism. Second, by adjusting the pH of the emulsion to weakly alkaline (8.5~9.5), the hydroxyl groups on the surface of WO3 will become negatively charged, generating electrostatic repulsion between particles, which complements the steric hindrance and further prevents aggregation. Finally, a short-term ultrasonic treatment is applied during mixing, using the cavitation shock waves of ultrasound to disperse the soft aggregates that have already formed, ensuring that each original particle is released. The three work together: ultrasound is responsible for "opening," spatial steric hindrance and electrostatics are responsible for "locking," and finally, when the coating is drying, Pt / WO3 can be evenly distributed throughout the entire coating, without the problem of decreased sensitivity or uneven color development caused by agglomeration.

[0038] (5) The hydrogen-chromic material of the present invention is an environmentally friendly, safe and easy-to-prepare water-based product that can be flexibly prepared into self-adhesive tapes or coatings. It can be widely used in hydrogen leak detection, especially suitable for leak monitoring of hydrogen energy facilities, to achieve low-cost, large-area, and visualized passive safety early warning. Attached Figure Description

[0039] Figure 1 This is a flowchart of the preparation method of the hydrogen-induced color-changing material of the present invention; Figure 2 This is a comparison image of the color change before and after 4% H2 / Ar mixed gas was introduced under vacuum and sealed conditions in Application Example 7 of the present invention. Figure 3 This is an application example 7 of the present invention, showing the spectra before and after color change after introducing 4% H2 / Ar mixed gas under vacuum conditions. Detailed Implementation

[0040] See Figure 1 This invention discloses a method for preparing a platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material, comprising the following steps: S1. Preparation of initiator aqueous solution: The initiator is mixed evenly with deionized water to obtain an initiator aqueous solution.

[0041] The mass ratio between the initiator and deionized water can be 1:120 to 1:80, for example 1:120, 1:100 or 1:80, preferably 1:100.

[0042] The initiator can be at least one of ammonium persulfate, azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, potassium persulfate, and sodium persulfate. It can be one or a combination of two or more, with potassium persulfate being preferred.

[0043] The preferred reaction conditions are heating to 80°C and stirring under nitrogen protection.

[0044] S2. Preparation of emulsifier aqueous solution: The emulsifier, Triton-100 and deionized water were mixed evenly to obtain an emulsifier aqueous solution.

[0045] The mass ratio of emulsifier, Triton-100 and deionized water can be 4:3:25 to 4:3:15, for example 4:3:25, 4:3:20 or 4:3:15, preferably 4:3:20.

[0046] The emulsifier may be at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate and allyloxyhydroxypropyl sulfonate (e.g., sodium allyloxyhydroxypropyl sulfonate), that is, one or a combination of two or more, with sodium dodecyl sulfate being preferred.

[0047] The preferred reaction conditions are stirring at room temperature.

[0048] S3. Preparation of pre-emulsified mixed monomers: Acrylic monomers are added to an aqueous emulsifier solution and stirred until homogeneous to obtain a pre-emulsified mixed monomer.

[0049] The mass ratio between acrylic monomer and emulsifier aqueous solution can be 10:1 to 20:1, for example 10:1, 15:1, 20:1, preferably 20:1.

[0050] The acrylic monomer can be at least three of the following: acrylic acid, methyl methacrylate, isooctyl acrylate, ethyl acrylate, hydroxyethyl acrylate, and butyl acrylate, that is, a combination of three or more of them can be used.

[0051] The acrylic monomers preferably include butyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, and isooctyl acrylate, and the mass ratio of butyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate and isooctyl acrylate is preferably 2:1:1:4:12.

[0052] S4. Reaction of pre-emulsified mixed monomers with initiator: Add a portion of the pre-emulsified mixed monomers to the initiator aqueous solution, and then add a certain amount of initiator aqueous solution (the initiator aqueous solution with the same solute as the initiator aqueous solution prepared in S1) and stir until the liquid turns bluish.

[0053] The mass of the pre-emulsified mixed monomers added to the initiator aqueous solution is preferably 10% of the mass of the pre-emulsified mixed monomers prepared in step S3. After adding a portion of the pre-emulsified mixed monomers to the initiator aqueous solution, the mixture is stirred and emulsified for 15 minutes. The initiator mass fraction of the initiator aqueous solution added later is preferably 5%, and the mixture is stirred for 20 minutes after addition.

[0054] S5. Preparation of acrylic emulsion: The remaining pre-emulsified mixed monomers are added dropwise to the solution of S4 to obtain an acrylic emulsion.

[0055] The remaining pre-emulsified mixed monomers can be added to the solution of S4 in batches, preferably 10 mL per batch, and added dropwise over 3 to 4 hours. Then, the solution is heated to 85°C and kept at that temperature for 1 hour. After naturally cooling to room temperature, it is filtered to obtain an acrylic emulsion. The pH value of the acrylic emulsion is preferably 6 to 8, which can be adjusted using a sodium bicarbonate aqueous solution. Specifically, the adjustment can be made by adding a 10% sodium bicarbonate aqueous solution every 5 minutes.

[0056] S6. Preparation of platinum-supported tungsten trioxide composite nanorods: WO3 nanorods, ethylene glycol, platinum chlorate hexahydrate, and deionized water were mixed and reacted. After the reaction was complete, the product was separated by filtration, washed, and dried to obtain Pt / WO3 composite nanorods.

[0057] The preferred mass ratio of WO3 nanorods, ethylene glycol, platinum chlorate hexahydrate, and deionized water is 9:36:0.17:200.

[0058] After filtration and separation, it is preferable to wash with deionized water multiple times, such as 3, 4 or 5 times; the preferred reaction temperature is 150℃~190℃, and the preferred reaction time is 5h, which can be carried out in a reaction vessel; the preferred drying temperature is 80℃, and the preferred drying time is 12h.

[0059] S7. Preparation of hydrogen-induced color-changing materials: Pt / WO3 composite nanorods were added to an acrylic emulsion, mixed evenly, and then filtered to obtain a platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material.

[0060] The amount of Pt / WO3 composite nanorod material added can be 2% to 6% of the total mass of the hydrogen chromogenic material, for example 2%, 3%, 5% or 6%, preferably 6%.

[0061] This invention also discloses a platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material, which is prepared using any of the preparation methods for platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic materials disclosed in this invention.

[0062] The amount of Pt / WO3 composite nanorods added to the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material can be 2% to 6% of the total mass of the hydrochromic material, for example, 2%, 3%, 5% or 6%, preferably 6%.

[0063] This invention also discloses the application of platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material in hydrogen leak detection. The platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material can be prepared into hydrogen-sensitive color-changing tape, hydrogen-sensitive color-changing coating, or hydrogen-sensitive color-changing patch, and applied in hydrogen leak detection (e.g., hydrogen leak detection and continuous monitoring of potentially high-risk leak locations such as pipe joints, valves, tank welds, and hydrogen refueling ports in hydrogen energy facilities).

[0064] For example, a platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material can be coated onto a BOPP film, and PET can be used as a release film to prepare a hydrogen-sensitive color-changing tape. The coating thickness of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material can be 0.2 mm to 0.5 mm, for example, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm, preferably 0.2 mm.

[0065] The following are examples of methods for preparing platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic materials: Example 1: S1. Preparation of initiator aqueous solution: Add 20g of deionized water to a three-necked flask, place it in a water bath and heat it to 80℃. Add 0.1g of potassium persulfate and stir for 15 minutes to obtain an initiator aqueous solution.

[0066] S2. Preparation of emulsifier aqueous solution: Add 0.4g sodium dodecyl sulfate, 0.3g Triton-100 and 2g deionized water to a beaker and stir at room temperature to prepare an emulsifier aqueous solution.

[0067] S3. Preparation of pre-emulsified mixed monomers: 4g butyl acrylate, 2g acrylic acid, 2g hydroxyethyl acrylate, 24g isooctyl acrylate, and 8g methyl methacrylate were added to an aqueous emulsifier solution to prepare a pre-emulsified mixed monomer.

[0068] S4. Reaction of pre-emulsified mixed monomers with initiator: In a three-necked flask, heat the mixture to 80°C in a water bath. Add 10% (by mass) of the pre-emulsified mixed monomers prepared in step S3 to the three-necked flask and stir to emulsify for 15 minutes, ensuring the remaining pre-emulsified mixed monomer solution remains homogeneous. Add 1g of a 5% (by mass) initiator aqueous solution (i.e., a 5% (by mass) potassium persulfate aqueous solution) to the three-necked flask and stir for 20 minutes until the liquid system exhibits a bluish tint.

[0069] S5. Preparation of acrylic emulsion: The remaining pre-emulsified monomer mixture in S4 was added dropwise in batches of 10 mL to a three-necked flask over approximately 4 hours. The temperature was then raised to 85°C and maintained for 1 hour. After the mixture was allowed to cool naturally to room temperature, it was filtered through a wire mesh into a beaker. A 10% sodium bicarbonate aqueous solution was added dropwise every 5 minutes to adjust the pH to 7, thus obtaining the acrylic emulsion.

[0070] S6. Preparation of platinum-supported tungsten trioxide composite nanorods: 4.5 g of WO3 nanorod material, 18 g of ethylene glycol, 0.085 g of chloroplatinic acid hexahydrate and 100 mL of deionized water were placed in a beaker, magnetically stirred and mixed evenly, and then placed in a reaction vessel and heated at 180 °C for 5 h. After filtration and separation, the material was washed three times with deionized water and dried at 80 °C for 12 h to obtain Pt / WO3 composite nanorod material.

[0071] S7. Preparation of hydrogen-induced color-changing materials: Pt / WO3 composite nanorods were added to the acrylic emulsion prepared in step S5, with the amount of Pt / WO3 composite nanorods added being 2% of the total mass of the mixture, to obtain a platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material.

[0072] Example 2: The difference between this embodiment and Embodiment 1 is that: In S7, the amount of Pt / WO3 composite nanorod material added is 4% of the total mass of the mixture.

[0073] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0074] Example 3: The difference between this embodiment and Embodiment 1 is that: In step S7, the amount of Pt / WO3 composite nanorod material added is 6% of the total mass of the mixture.

[0075] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0076] Example 4: The difference between this embodiment and Embodiment 1 is that: In S1, the addition of 0.1g potassium persulfate is replaced with the addition of 0.1g ammonium persulfate.

[0077] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0078] Example 5: The difference between this embodiment and Embodiment 1 is that: In S1, the addition of 0.1g potassium persulfate is replaced by the addition of 0.05g potassium persulfate and 0.05g azobisisobutyronitrile.

[0079] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0080] Example 6: The difference between this embodiment and Embodiment 1 is that: In S1, the addition of 0.1g potassium persulfate is replaced by the addition of 0.04g ammonium persulfate, 0.03g azobisisobutyronitrile and 0.03g azobisisovalerate.

[0081] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0082] Example 7: The difference between this embodiment and Embodiment 1 is that: In S2, the addition of 0.4g sodium dodecyl sulfate is replaced with the addition of 0.4g sodium dodecylbenzenesulfonate.

[0083] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0084] Example 8: The difference between this embodiment and Embodiment 1 is that: In S2, the addition of 0.4g sodium dodecyl sulfate is replaced by the addition of 0.2g sodium dodecylbenzenesulfonate and 0.2g sodium dodecyl sulfate.

[0085] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0086] Example 9: The difference between this embodiment and Embodiment 1 is that: In S2, the addition of 0.4g sodium dodecyl sulfate is replaced by the addition of 0.1g sodium dodecylbenzenesulfonate, 0.2g sodium dodecyl sulfate, and 0.2g sodium allyloxyhydroxypropyl sulfonate.

[0087] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0088] Example 10: The difference between this embodiment and Embodiment 1 is that: In step S3, replacing the addition of 4g butyl acrylate, 2g acrylic acid, 2g hydroxyethyl acrylate, 24g isooctyl acrylate, and 8g methyl methacrylate to the emulsifier aqueous solution is to add 4g butyl acrylate, 2g acrylic acid, 2g hydroxyethyl acrylate, 28g isooctyl acrylate, and 4g methyl methacrylate to the emulsifier aqueous solution.

[0089] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0090] Example 11: The difference between this embodiment and Embodiment 1 is that: In step S3, replacing the addition of 4g butyl acrylate, 2g acrylic acid, 2g hydroxyethyl acrylate, 24g isooctyl acrylate, and 8g methyl methacrylate to the emulsifier aqueous solution is to add 4g butyl acrylate, 2g acrylic acid, 2g hydroxyethyl acrylate, 20g isooctyl acrylate, and 12g methyl methacrylate to the emulsifier aqueous solution.

[0091] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0092] Example 12: The difference between this embodiment and Embodiment 1 is that: In step S3, replacing the addition of 4g butyl acrylate, 2g acrylic acid, 2g hydroxyethyl acrylate, 24g isooctyl acrylate, and 8g methyl methacrylate to the emulsifier aqueous solution is to add 2g butyl acrylate, 4g acrylic acid, 2g hydroxyethyl acrylate, 24g isooctyl acrylate, and 8g methyl methacrylate to the emulsifier aqueous solution.

[0093] Apart from the differences mentioned above, the other implementation steps and methods are the same as in Example 1.

[0094] Application Example 1: Using BOPP film as the film-forming substrate, the platinum-loaded tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material prepared in Example 1 was coated onto the BOPP film using a coating machine. The coating thickness was 0.2 mm (the coating thickness was controlled by adjusting the doctor blade of the coating machine). PET was used as the release film to prepare hydrogen-sensitive color-changing tape.

[0095] Application Example 2: The difference between this application example and Application Example 1 is: The coating thickness was changed to 0.3mm.

[0096] Apart from the differences mentioned above, the other application steps and methods are the same as in Application Example 1.

[0097] Application Example 3: The difference between this application example and Application Example 1 is: The coating thickness has been changed to 0.5mm.

[0098] Apart from the differences mentioned above, the other application steps and methods are the same as in Application Example 1.

[0099] The prepared hydrogen-sensitive color-changing tape under vacuum conditions with 4% H2 / Ar mixed gas was compared before and after color change, and the spectra before and after color change are shown below. Figure 2 and Figure 3 As shown.

[0100] Application Example 4: Using BOPP film as the film-forming substrate, the platinum-loaded tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material prepared in Example 2 was coated onto the BOPP film using a coating machine. The coating thickness was 0.2 mm (the coating thickness was controlled by adjusting the doctor blade of the coating machine). PET was used as the release film to prepare hydrogen-sensitive color-changing tape.

[0101] Application Example 5: The difference between this application example and application example 4 is: The coating thickness was changed to 0.3mm.

[0102] Apart from the differences mentioned above, the other application steps and methods are the same as in application example 4.

[0103] Application Example 6: The difference between this application example and application example 4 is: The coating thickness has been changed to 0.5mm.

[0104] Apart from the differences mentioned above, the other application steps and methods are the same as in application example 4.

[0105] Application Example 7: Using BOPP film as the film-forming substrate, the platinum-loaded tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material prepared in Example 3 was coated onto the BOPP film using a coating machine. The coating thickness was 0.2 mm (the coating thickness was controlled by adjusting the doctor blade of the coating machine). PET was used as the release film to prepare hydrogen-sensitive color-changing tape.

[0106] Application Example 8: The difference between this application example and application example 7 is: The coating thickness was changed to 0.3mm.

[0107] Apart from the differences mentioned above, the other application steps and methods are the same as in Application Example 7.

[0108] Application Example 9: The difference between this application example and application example 7 is: The coating thickness has been changed to 0.5mm.

[0109] Apart from the differences mentioned above, the other application steps and methods are the same as in Application Example 7.

[0110] Table 1 shows the comparison results of the color-changing performance of the hydrogen-sensitive color-changing tapes prepared in Application Examples 1-9 under vacuum sealing conditions after being purged with 4% H2 / Ar mixed gas and 1% H2 / Ar mixed gas, respectively.

[0111] Table 1. Comparison of the color-changing properties of hydrogen-sensitive color-changing tapes prepared in Application Examples 1-9

[0112] Table 2 shows the comparison results of the color change time and peel strength of the hydrogen-sensitive color-changing tapes prepared in Application Examples 1-9 after being introduced into a vacuum-sealed environment with 4% H2 / Ar mixed gas.

[0113] Table 2 Comparison of color-changing time and peel strength of hydrogen-sensitive color-changing tapes prepared in Application Examples 1-9

[0114] Table 1 shows that, regardless of whether the H2 / Ar mixed gas condition is 1% or 4%, the hydrogen-sensitive color-changing tape prepared with 6% Pt / WO3 composite nanorods exhibits the shortest color-changing response time compared to tapes prepared with 2% and 4% Pt / WO3 composite nanorods. Furthermore, with a 6% Pt / WO3 composite nanorod addition, among hydrogen-sensitive color-changing tapes with different coating thicknesses, the 0.2 mm coating thickness results in the shortest color-changing response time. Table 2 shows that, with the same Pt / WO3 composite nanorod addition, a thicker coating results in greater peel strength. Similarly, with the same coating thickness, a higher Pt / WO3 composite nanorod addition results in greater peel strength. Therefore, taking into account both the color change response time and peel strength, the optimal addition amount of Pt / WO3 composite nanorod material in the preparation method of the hydrogen-chromic material of the present invention is 6% of the total mass of the hydrogen-chromic material, and the optimal coating thickness of the hydrogen-chromic material in the application of the hydrogen-chromic material of the present invention is 0.2 mm.

[0115] The various embodiments and application examples of this invention are not intended to limit the invention. In actual production and application, the process parameters and proportions can be scaled up by multiples to meet production needs.

[0116] Unless otherwise specified or further limited to one preferred or optional technical means being another, the preferred and optional technical means disclosed in this invention can be arbitrarily combined to form several different technical solutions.

Claims

1. A method for preparing platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material, characterized in that... Includes the following steps: S1: Mix the initiator with deionized water until homogeneous to obtain an initiator aqueous solution; S2: Mix the emulsifier, Triton-100 and deionized water evenly to obtain an emulsifier aqueous solution; S3: Add acrylic monomer to the emulsifier aqueous solution and stir evenly to obtain a pre-emulsified mixed monomer; S4: Add a portion of the pre-emulsified mixed monomers to the initiator aqueous solution, and then add a certain amount of initiator aqueous solution and stir until the liquid turns bluish; S5: Add the remaining pre-emulsified mixed monomers dropwise to the solution in S4 to obtain an acrylic emulsion; S6: Mix WO3 nanorod material, ethylene glycol, platinum chlorate hexahydrate and deionized water evenly and react them. After the reaction is complete, filter, wash and dry the product to obtain Pt / WO3 composite nanorod material. S7: Pt / WO3 composite nanorods were added to the acrylic emulsion, mixed evenly, and then filtered to obtain platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material.

2. The preparation method of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material according to claim 1, characterized in that... In S1, the mass ratio between the initiator and deionized water is 1:120 to 1:80, and the initiator is at least one of ammonium persulfate, azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, potassium persulfate, and sodium persulfate.

3. The preparation method of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material according to claim 1, characterized in that... In S2, the mass ratio of emulsifier, Triton-100 and deionized water is 4:3:25 to 4:3:15, and the emulsifier is at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate and allyloxyhydroxypropyl sulfonate.

4. The preparation method of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material according to claim 1, characterized in that... In S3, the mass ratio between the acrylic monomer and the emulsifier aqueous solution is 10:1 to 20:1, and the acrylic monomer is at least three of the following: acrylic acid, methyl methacrylate, isooctyl acrylate, ethyl acrylate, hydroxyethyl acrylate, and butyl acrylate.

5. The preparation method of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material according to claim 1, characterized in that... In step S4, the mass of the pre-emulsified mixed monomer added to the initiator aqueous solution is 10% of the mass of the pre-emulsified mixed monomer prepared in step S3.

6. The preparation method of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material according to claim 1, characterized in that... The pH value of the acrylic emulsion in S5 is 6-8.

7. The preparation method of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material according to claim 1, characterized in that... In S6, the mass ratio of WO3 nanorod material, ethylene glycol, platinum chlorate hexahydrate and deionized water is 9:36:0.17:

200.

8. The preparation method of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material according to claim 1, characterized in that... In S7, the amount of Pt / WO3 composite nanorod material added is 2% to 6% of the total mass of the hydrogen chromogenic material.

9. A platinum-supported tungsten trioxide-doped aqueous acrylic hydrochromic material, characterized in that... The platinum-supported tungsten trioxide-doped aqueous acrylate hydrochromic material was prepared using any one of claims 1-8.

10. The application of the platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material prepared by the preparation method of any one of claims 1-8, or the platinum-supported tungsten trioxide-doped aqueous acrylic hydrogen chromogenic material of claim 9, in hydrogen leak detection.

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