A dual-probe photoluminescent coating, coating material, and its application that are both sensitive to oxygen concentration / pressure and temperature.

Abstract

This invention discloses a dual-probe photoluminescent coating, a coating material, and its applications that are sensitive to both oxygen concentration / pressure and temperature. Its composition includes temperature-sensitive photoluminescent microparticles of aggregation-induced emission (AIE) molecules encapsulated in a polymer and oxygen concentration / pressure-sensitive photoluminescent molecules. The oxygen concentration / pressure-sensitive photoluminescent molecules are ruthenium metal complexes. This invention utilizes polymer-encapsulated AIE molecules, restricting the crystallization behavior of AIE molecules through a polymer network, thus achieving reversible temperature measurement. The preparation method of the polymer-encapsulated AIE microparticles is simple and efficient, with uniform particle size distribution that can be adjusted within a certain range. The oxygen concentration / pressure and temperature-sensitive coating achieves a porous structure and faster response speed by using an oxygen-permeable polymer matrix and adding fillers. Experimental results show that the coating can achieve a microsecond-level response speed due to the addition of fillers.

Description

Technical Field

[0001] This invention relates to the field of coatings and coating preparation, specifically to a dual-sensitive polymer-based coating and coating based on temperature-sensitive photoluminescent microparticles of polymer-encapsulated aggregation-induced emission (AIE) molecules and oxygen concentration-sensitive photoluminescent molecules, as well as their preparation and application. Background Technology

[0002] Oxygen concentration / pressure sensitive coatings are a non-contact, large-area optical testing technology that forms a coating on a substrate surface and measures pressure. The principle is based on the dissipation of excited-state fluorescent molecule energy by oxygen molecules, leading to fluorescence quenching, and thus the pressure change is calculated from the oxygen concentration. Compared to traditional point measurement techniques, it offers advantages such as high spatial resolution, large data acquisition, and the ability to capture pressure peaks, making it widely used in aerodynamics. Commonly used oxygen-sensitive probes include polycyclic aromatic hydrocarbons such as pyrene and its derivatives, and metal complexes such as ruthenium, platinum, and palladium. Pyrene and its derivatives are prone to migration and sublimation in coatings, resulting in poor coating stability. While platinum and palladium metal porphyrin complexes offer high oxygen sensitivity and large Stokes shifts, their long fluorescence lifetimes make it difficult to achieve faster response times. Compared to these two types of oxygen-sensitive probes, ruthenium complexes possess a larger Stokes shift, stronger photobleaching resistance, and higher oxygen sensitivity, along with a shorter fluorescence lifetime and faster coating response, giving them unique advantages in unsteady flow field pressure measurement. However, since ruthenium complexes also exhibit temperature responsiveness, temperature correction is required for oxygen concentration / pressure measurements. Currently, reference probes used for temperature correction mainly include thermosensitive phosphors, small-molecule fluoresceins, and carbon quantum dots. However, these probes still suffer from problems such as low temperature sensitivity, slow response speed, and poor reversibility. Therefore, there are currently no mature oxygen concentration / pressure and temperature-sensitive coatings or coatings based on ruthenium complexes that have been widely applied.

[0003] Aggregation-induced emission (AIE) molecules are a new type of fluorescent molecule developed in recent years. They have a wide range of wavelength selectivity and have attracted widespread attention in the fields of biomedicine and chemical sensing. Summary of the Invention

[0004] The purpose of this invention is to provide a polymer-based coating with dual sensitivity to oxygen concentration / pressure and temperature, consisting of temperature-sensitive photoluminescent microparticles and oxygen concentration-sensitive photoluminescent molecules loaded with aggregation-induced emission (AIE) molecules, as well as a coating preparation method and application.

[0005] This invention encapsulates AIE molecules with a polymer to obtain temperature-sensitive photoluminescent nanoparticles with diameters ranging from nanometers to submicrometers. A coating formed from these particles, along with an oxygen concentration / pressure-sensitive photoluminescent ruthenium complex and a polymer matrix, creates a dual-sensitivity coating for both oxygen concentration / pressure and temperature. This coating enables simultaneous measurement of oxygen concentration and / or pressure and temperature, correcting for temperature effects during pressure measurements. By controlling the crystallization behavior of AIE molecules through a polymer network, reversible temperature responsiveness is achieved, resulting in a dual-probe oxygen concentration / pressure and temperature-sensitive coating capable of multiple repeatable measurements.

[0006] The photoluminescent coating provided by this invention, which is dually sensitive to oxygen concentration / pressure and temperature, comprises temperature-sensitive photoluminescent microparticles and oxygen concentration / pressure-sensitive photoluminescent molecules encapsulated with polymer-encapsulated aggregation-induced emission (AIE) molecules.

[0007] The mass ratio of the temperature-sensitive photoluminescent microparticles and the oxygen concentration / pressure-sensitive photoluminescent molecule loaded with the polymer aggregation-induced emission molecule (AIE) can be 4:1 to 20:1, and the specific mass ratio can be determined according to the light intensity ratio of the two components.

[0008] The oxygen concentration / pressure-sensitive photoluminescent molecule (oxygen-sensitive probe) is a complex with ruthenium as the central atom, i.e., a ruthenium metal complex;

[0009] The ruthenium metal complex has ruthenium as the central atom and bipyridine and / or biphenyl-phenanthroline compounds with carboxyl and / or amino groups as ligands.

[0010] Specifically, the ruthenium metal complex contains cations with the following structural formula:

[0011]

[0012] Wherein, R can be -H, C1-C6 alkyl (specifically -CH3, -C2H5, -C3H7, -C4H9, -C5H) 11 -C6H 13 ), -COOH or -NH2, but at least one or two Rs are amino or carboxyl functional groups;

[0013] or:

[0014]

[0015] Wherein, R can be -H, C1-C6 alkyl (specifically -CH3, -C2H5, -C3H7, -C4H9, -C5H). 11 -C6H 13 ), -COOH or -NH2, but at least one or two Rs are amino or carboxyl functional groups;

[0016] or:

[0017]

[0018] Wherein, R can be -H, C1-C6 alkyl (specifically -CH3, -C2H5, -C3H7, -C4H9, -C5H). 11 -C6H 13 ), -COOH or -NH2, but at least one or two Rs are amino or carboxyl functional groups;

[0019] or:

[0020]

[0021] Wherein, R can be -H, C1-C6 alkyl (specifically -CH3, -C2H5, -C3H7, -C4H9, -C5H). 11 -C6H 13 ), -COOH or -NH2, but at least one or two Rs are amino or carboxyl functional groups;

[0022] Or a mixture of them.

[0023] The temperature-sensitive photoluminescent microparticles of polymer-encapsulated aggregation-induced emission (AIE) molecules are polymer-encapsulated aggregation-induced emission (AIE) molecule microparticles;

[0024] The aggregation-induced emission molecule (AIE) is at least one of tetraphenylethylene and its derivatives, triphenylamine and its derivatives, phenoxazine and its derivatives, phenothiazine and its derivatives, and carbazole and its derivatives, which have different functional groups.

[0025] Specifically, the aggregation-induced emission molecule (AIE) includes at least one of the compounds represented by Formula I, Formula II, Formula III, Formula IV and Formula V:

[0026]

[0027] In Formula I and Formula II, R1 is independently selected from at least one of -H, -NO2, C1-C6 alkyl and nitro groups (such as nitrophenyl), and at least one R1 represents -NO2 or a nitro group;

[0028] In Formulas III, IV and V, R2 is independently selected from groups containing nitro groups (such as nitrophenyl).

[0029] More specifically, the aggregation-induced emission molecule is selected from at least one of the following compounds:

[0030]

[0031] The polymer carrying aggregation-induced emission (AIE) molecules can be at least one of the following: polyethylene-vinyl alcohol copolymer, acrylonitrile copolymer, polyacrylate, polyurethane, polyacrylonitrile, polyamide, polyester, epoxy resin, and silicone-based amphiphilic block copolymer.

[0032] The temperature-sensitive photoluminescent microparticles containing aggregation-induced emission (AIE) molecules loaded with polymers were prepared by a method comprising the following steps:

[0033] 1) Dissolve or disperse the aggregation-induced emission molecules and the polymer monomer or polymer in a solvent, and stir to obtain a homogeneous mixed solution;

[0034] 2) The mixed solution is used to prepare polymer-encapsulated AIE microparticles by at least one method such as solvent evaporation, emulsion polymerization, spray drying, or nanoprecipitation.

[0035] The mass ratio of aggregation-induced emission (AIE) molecules to polymer molecules can be 1:10 to 50, specifically 1:10, 1:20, 1:30, 1:40, or 1:50.

[0036] The solvent may be at least one or a mixture of N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, chloroform, ethanol, and water.

[0037] The diameter of the AIE microparticles encapsulated in the polymer ranges from 50 nm to 200 nm.

[0038] The photoluminescent coating, which is sensitive to both oxygen concentration / pressure and temperature, also includes an oxygen-permeable polymer matrix.

[0039] The oxygen concentration / pressure sensitive photoluminescent molecules (oxygen-sensitive probes) are distributed in the oxygen-permeable polymer matrix in the form of chemical reaction bonding and / or physical adsorption.

[0040] The oxygen-permeable polymer matrix may be at least one of silicon-based polymers, fluoroacrylic polymers, polystyrene, and cellulose polymers; preferably at least one of room temperature vulcanizing silicone rubber (RTV), polystyrene, polydimethylsiloxane, poly(4-tert-butylstyrene), polyisopropyl methacrylate, and ethyl cellulose, or a mixture thereof.

[0041] The photoluminescent oxygen concentration / pressure and temperature-sensitive coating further includes fillers.

[0042] The filler may be at least one of the following: organosilicon microspheres, titanium dioxide, silica, mesoporous silica, silica aerogel, boron nitride, aluminum oxide, barium sulfate, and calcium carbonate.

[0043] The particle size of the filler can be 30nm to 2μm, specifically 30nm, 50nm, 100nm, 500nm, 1μm, or 2μm.

[0044] Photoluminescent coatings that are sensitive to both oxygen concentration / pressure and temperature, as described above, are also within the scope of protection of this invention.

[0045] In the photoluminescent coating that is both oxygen concentration / pressure and temperature sensitive, the mass ratio of the temperature-sensitive photoluminescent microparticles to the oxygen concentration / pressure-sensitive photoluminescent molecules (ruthenium metal complex) can be 4:1 to 20:1; the mass of both accounts for 1% to 10% of the total mass of the coating (the total mass of the coating after solvent evaporation and curing includes the mass of the temperature-sensitive photoluminescent microparticles, the oxygen concentration / pressure-sensitive photoluminescent molecules (oxygen-sensitive probes), fillers, and oxygen-permeable polymer matrix; here it refers to the mass of the temperature-sensitive photoluminescent microparticles, the oxygen concentration / pressure-sensitive photoluminescent molecules, and their percentage of the final coating mass);

[0046] The oxygen-permeable polymer matrix accounts for 30% to 80% of the total mass of the coating;

[0047] The filler content is the remaining mass of the coating.

[0048] The present invention also provides a method for preparing the above-mentioned photoluminescent coating that is sensitive to both oxygen concentration / pressure and temperature.

[0049] The method for preparing photoluminescent oxygen concentration / pressure and temperature-sensitive coatings and coating layers provided by this invention includes the following steps:

[0050] 1) The coating is obtained by mixing temperature-sensitive photoluminescent microparticles of polymer-encapsulated aggregation-induced emission molecules (AIE) with oxygen concentration / pressure-sensitive photoluminescent molecules (ruthenium metal complex), solvent, optional oxygen-permeable polymer matrix, and filler, stirring, and ultrasonic homogenization.

[0051] 2) Apply the coating to the substrate and cure it to obtain a photoluminescent coating that is sensitive to both oxygen concentration / pressure and temperature.

[0052] In step 1) of the above method, the mass ratio of the temperature-sensitive photoluminescent particles and the oxygen concentration / pressure-sensitive photoluminescent molecules (ruthenium metal complex) can be 4:1 to 20:1. The specific mass ratio can be determined according to the light intensity ratio of the two components of the coating, and the mass of the two components accounts for 1% to 10% of the total mass of the coating.

[0053] In step 1), the oxygen-permeable polymer matrix accounts for 30% to 80% of the total mass of the coating, and the remainder is filler.

[0054] In step 1), the solvent is at least one or a mixture of dichloromethane, chloroform, chlorobenzene, toluene, tetrahydrofuran, and ethanol.

[0055] In step 1), the solvent content can be configured according to different coating preparation methods, and the total mass concentration of the coating is 20 mg / mL to 50 mg / mL.

[0056] In step 2), the coating method includes at least one of the following: casting method, spin coating method, stencil method, spraying method, brush coating method, and inkjet printing;

[0057] The curing is carried out at room temperature, and the substrate may be at least one of glass, metal, polymer, composite material, etc.

[0058] The application of the aforementioned photoluminescent oxygen concentration / pressure and temperature-sensitive coatings or coatings in the detection of oxygen concentration, air pressure and temperature is also within the scope of protection of this invention.

[0059] In the application described, the coating or coating layer is used to detect oxygen concentration, air pressure, or temperature individually, or to detect oxygen concentration, air pressure, and temperature simultaneously.

[0060] The detection is a non-contact optical curve or two-dimensional image detection.

[0061] The dual-probe photoluminescent polymer coating of the present invention has stable performance and can be reused for a long time.

[0062] The present invention has the following advantages:

[0063] 1. This invention employs polymer-encapsulated aggregation-induced emission (AIE) molecules and restricts the crystallization behavior of AIE molecules through a polymer network, thereby achieving reversible temperature measurement.

[0064] 2. The preparation method of polymer-encapsulated aggregation-induced emission (AIE) molecules is simple and efficient, with uniform particle size distribution that can be adjusted within a certain range.

[0065] 3. The oxygen concentration / pressure and temperature dual-sensitive coating achieves a porous structure and faster response speed by employing an oxygen-permeable polymer matrix and adding fillers. Experimental results show that the coating can achieve a microsecond-level response speed due to the addition of fillers.

[0066] This invention utilizes temperature-sensitive photoluminescent microparticles containing aggregation-induced emission (AIE) molecules as temperature-sensitive probes to develop a photoluminescent coating based on AIE molecules and ruthenium complexes that is sensitive to both oxygen concentration / pressure and temperature. The dual-sensitivity photoluminescent coating is prepared using various methods. This coating can be used alone as an oxygen concentration / pressure-sensitive or temperature-sensitive coating, or as a dual-sensitivity coating for both oxygen concentration / pressure and temperature, enabling temperature correction during oxygen concentration / pressure measurement and simultaneous measurement of temperature and oxygen concentration / pressure. Attached Figure Description

[0067] Figure 1 In Figure a, the particle size distribution of the polymer-encapsulated aggregation-induced emission molecular microparticles prepared in Example 1 of this invention is shown, and in Figure b, the surface temperature distribution of the experimental model measured using a dual-probe oxygen concentration / pressure and temperature-sensitive coating is shown.

[0068] Figure 2 In Figure a, the particle size distribution of the polymer-encapsulated AIE molecules prepared in Example 2 of this invention is shown, and in Figure b, the surface pressure distribution of the dynamic model measured using a dual-probe oxygen concentration / pressure and temperature-sensitive coating is shown.

[0069] Figure 3 and Figure 4 The figures show the oxygen concentration response spectrum and linear response curve obtained when the dual-sensitive coating of Example 3 of the present invention is used alone as an oxygen concentration / pressure coating.

[0070] Figure 5 The temperature response spectrum curve of the dual-sensitive coating prepared in Example 4 of the present invention when used alone as a temperature-sensitive coating.

[0071] Figure 6 , 7 The pressure and temperature results measured when the dual-sensitive coating prepared in Example 5 of this invention is used as a dual-sensitive coating, and the cyclic test results of the temperature-sensitive component are respectively.

[0072] Figure 8 , 9 The images shown are the dynamic response curve of the dual-sensitive coating prepared in Example 6 of this invention and a two-dimensional image of shock wave velocity measurement.

[0073] Figure 10 The time-scan measurement results of the light intensity change of the dual-sensitive coating prepared in Example 7 of the present invention under continuous excitation conditions.

[0074] Figure 11 This indicates that the coating prepared by adding uncoated TPE4N powder to Example 8 of the present invention exhibits irreversible light intensity and temperature deviation from the set value during the heating and cooling process. However, the coating with added TPE4N nanoparticles can achieve reversible temperature measurement. Detailed Implementation

[0075] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0076] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0077] Example 1

[0078] 4,4'-(2,2-stilbene-1,1-triyl)tri(nitrobenzene) (TPE-3N) was synthesized according to the reference (Zhao W, He Z, Peng Q, et al. Highly sensitive switching of solid-state luminescence by controlling intersystem crossing[J]. Nature Communications, 2018, 9(1):3044.).

[0079] A solution of tetraphenylethylene (3.32 g, 10 mmol, 100 mL DCM) was added dropwise to a mixture of nitric acid (68%, 48 mL) and glacial acetic acid (60 mL), and the mixture was stirred at room temperature (0 °C) for 4 h. The mixture was then poured into 100 mL of water and extracted with 150 mL of dichloromethane. The organic layer was washed with sodium bicarbonate solution, dried over anhydrous magnesium sulfate for 2 h, and filtered. The solvent was removed by evaporation. Finally, the product was recrystallized in a chloroform / n-hexane mixture to give yellow needle-like crystals.

[0080] 10 mg of TPE-3N dye (aggregation-induced emission molecule) and 200 mg of polyacrylonitrile were dissolved in 20 mL of N,N-dimethylformamide (DMF) (dye to polymer mass ratio 1:20). The solution was rapidly injected into 120 mL of deionized water under continuous stirring. The suspension was centrifuged, washed repeatedly with water, and then freeze-dried to obtain microparticles (AIE-NP) encapsulated with AIE molecules. The diameter of the nanoparticles was measured to be approximately 50 nm using a Malvern laser particle size analyzer. Figure 1 ).

[0081] According to the reference (Hou CC, Li TT, Cao S, et al. Incorporation of a[Ru(dcbpy)(bpy)2] 2+ photosensitizer and a Pt(dcbpy)Cl2catalyst into metal–organicframeworks for photocatalytic hydrogen evolution from aqueous solution[J].Journal of Materials Chemistry A, 2015, 3(19):10386-10394.) Synthesis [[Ru(dcbpy)(bpy)2] 2+ Cl2.

[0082]

[0083] 1mg of [[Ru(dcbpy)(bpy)2]] 2+ Cl2 was dissolved in a mixed solvent of 3 mL dichloromethane and toluene, and 4 g AIE-NP, 75 mg of 30 nm titanium dioxide nanoparticles and 50 mg of room temperature vulcanizing silicone rubber (RTV) were added. After ultrasonic treatment, the mixture was stirred evenly and sprayed onto the test aircraft model with a spray gun. The coating was cured at room temperature for 24 h to obtain a dual-probe oxygen concentration / pressure and temperature-sensitive coating.

[0084] The model was placed in a wind tunnel, and under 365nm excitation conditions, the light intensity changes of the green and red channels on the model wall were measured using a single color CCD camera under wind tunnel flow conditions. Based on the static calibration results, the surface temperature and pressure distribution were then obtained. Figure 1 (b)

[0085] Example 2

[0086] 20 mg of tetra(4-nitrophenyl)ethylene (TPE4N) dye and 600 mg of polyacrylonitrile (dye to polymer mass ratio 1:30) were dissolved in 30 mL of N,N-dimethylformamide (DMF). The solution was rapidly injected into 120 mL of deionized water under ultrasonic conditions. The suspension was centrifuged, washed repeatedly with water, and then freeze-dried to obtain nanoparticles coated with the AIE probe. The diameter of the nanoparticles was measured to be approximately 200 nm using a Malvern laser particle size analyzer. Figure 2 (a)

[0087] Preparation of ruthenium dichloride (4,4'-dicarboxy-bipyridine) complex Ru(dcbpy)2Cl2: Ruthenium trichloride trihydrate reacts with small molecules of 4,4'-dicarboxy-bipyridine using 0.4 mmol RuCl33H2O and 0.85 mmol (dcbby) as the solvent. The reaction temperature is 100–120 °C, and the reaction is carried out under a nitrogen atmosphere with stirring for 24 h. After the reaction is stopped, the insoluble matter is filtered off, the solvent is dried, and the mixture is recrystallized from acetone.

[0088] Preparation of [[Ru(dcbpy)2(bpy)] 2+ Cl2: Reaction of Ru(dcbpy)2Cl2 with bipyridine at a molar ratio of 1:1 (0.4 mmol each) using N,N-dimethylformamide as the solvent, at a reaction temperature of 100-120℃, under a nitrogen atmosphere, with stirring for 24 h, after which the reaction is stopped, insoluble matter is filtered off, and the solvent is dried under vacuum.

[0089] 1mg of [[Ru(dcbpy)2(bpy)]] 2+ Cl2 was dissolved in a mixed solvent of 3 mL dichloromethane and chlorobenzene, and 6 mg AIE-NP, 75 mg titanium dioxide nanoparticles with a particle size of 50 nm and 60 mg room temperature vulcanizing silicone rubber (RTV) were added. After ultrasonic treatment, the mixture was stirred evenly and sprayed onto polyetheretherketone (PEEK) pellets with a spray gun. The mixture was cured at room temperature for 24 h to obtain a dual-probe oxygen concentration / pressure and temperature-sensitive coating.

[0090]

[0091] The projectile was launched from a high-speed ballistic target at a speed of 500 m / s. It was excited by a high-power 405nm blue LED, and a color CCD camera captured the changes in light intensity across the projectile's surface via dual channels during flight. Based on static calibration, the surface pressure and temperature distribution of the projectile were then determined. Figure 2 (b)

[0092] Example 3

[0093] 50 mg of tris(4-nitrophenyl)amine dye and 500 mg of polyacrylonitrile were dissolved in 20 mL of N,N-dimethylformamide (DMF) (dye to polymer mass ratio 1:10). The solution was rapidly injected into 120 mL of deionized water under continuous stirring. The suspension was centrifuged and washed with water multiple times before being freeze-dried to obtain nanoparticles loaded with AIE probes. The diameter of the nanoparticles was measured to be 150 nm using a Malvern laser particle size analyzer.

[0094] Preparation of ruthenium trichloride (4,4'-dicarboxy-bipyridine) complex [Ru(dcbpy)3]Cl2: Ruthenium trichloride trihydrate (RuCl3·3H2O) was reacted with small molecules of 4,4'-dicarboxy-bipyridine (dcbpy). 0.3 mmol RuCl3·3H2O and 0.9 mmol (dcbpy) were added at a molar ratio of n(RuCl3·3H2O):n(dcbpy) = 1:3. N,N-dimethylformamide was used as the solvent, and the reaction was carried out at 100–120 °C under a nitrogen atmosphere. The mixture was stirred for 24 h, and the reaction was stopped. The insoluble matter was filtered off, the solvent was dried, and the mixture was recrystallized from acetone.

[0095] 1 mg of [Ru(dcbpy)3]Cl2 was dissolved in 3 mL of chloroform, and 10 mg of AIE-NP, 100 mg of boron nitride nanoparticles with a particle size of 100 nm and 60 mg of polystyrene were added. After ultrasonic treatment, the mixture was stirred evenly and coated onto a glass substrate using a spin coating method. The coating was cured at room temperature for 24 h to obtain a dual-probe oxygen concentration / pressure and temperature-sensitive coating.

[0096] The coating was used alone as an oxygen concentration sensor. The fluorescence spectrum of the coating in response to oxygen concentration was measured using a fluorophotometer. The coating was excited by 455 nm blue light. After purging with nitrogen for 3 minutes, its emission spectrum was measured, followed by purging with oxygen for 3 minutes, and finally, the fluorescence emission spectrum in response to oxygen concentration was obtained. Figure 3 ).

[0097] Furthermore, based on the fluorescence spectrum curves under different oxygen concentration conditions, the 560nm–600nm wavelength band was selected for intensity integration to obtain the sensitivity fitting curves of the coating under different oxygen concentration conditions. Figure 4 ).

[0098]

[0099] Example 4

[0100] 10 mg of 9-(4-nitrophenyl)-9-hydro-carbazole dye and 400 mg of polyacrylonitrile were dissolved in 20 mL of N,N-dimethylformamide (DMF) (dye to polymer mass ratio 1:40). The solution was rapidly injected into 120 mL of deionized water under continuous stirring or sonication. The suspension was centrifuged and washed with water multiple times before being freeze-dried to obtain nanoparticles coated with the AIE probe. The diameter of the nanoparticles was measured to be 100 nm using a Malvern laser particle size analyzer.

[0101] Preparation of bis(2,2'-bipyridine-4-carboxy-4'-methyl)ruthenium dichloride complex Ru(mcbpy)2Cl2: 0.3 mmol RuCl33H2O and 0.6 mmol 4'-methyl-2,2'-bipyridine-4-carboxylic acid (mcbby) were added to N,N-dimethylformamide solvent at a molar ratio of 1:2. The reaction was carried out at 100-120℃ under a nitrogen atmosphere and stirred for 24 h. The reaction was then stopped, the insoluble matter was filtered off, the solvent was dried, and the mixture was recrystallized from acetone.

[0102] Preparation of [[Ru(dpp)(mcbpy)2] 2+ Cl2: Ru(mcbpy)2Cl2 is reacted with 4,7-biphenyl-1,10-o-phenanthroline at a molar ratio of 1:1. The reaction solvent is N,N-dimethylformamide. The reaction temperature is 100-120℃. The reaction is stirred for 24 hours under a nitrogen atmosphere. The reaction is then stopped, the insoluble matter is filtered off, and the solvent is dried.

[0103]

[0104] 1 mg of [[Ru(dpp)(mcbpy)2] 2+ Cl2 was dissolved in 2 mL of dichloromethane, and 5 mg of AIE-NP, 60 mg of boron nitride nanoparticles with a particle size of 500 nm and 60 mg of room temperature vulcanizing silicone rubber (RTV) were added. The mixture was then brushed onto a metal model and cured at room temperature for 24 h to obtain a dual-probe oxygen concentration / pressure and temperature-sensitive coating.

[0105] The dual-probe coating was used alone as a temperature-sensitive coating, and its temperature spectrum curves under different temperature conditions were measured. The measurement equipment used a fluorescence spectrometer, and the temperature control was achieved using a matching high-temperature sample stage. A 1cm x 1cm square aluminum sheet coated with the coating was cut and fixed on the temperature control stage. Excitation was performed using 455nm blue light, and the temperature was set from 20℃ to 100℃. Fluorescence spectra were collected at room temperature (20℃), and after raising the temperature to 100℃ and holding for 10 minutes, the fluorescence spectra were measured again. This yielded the fluorescence spectrum curves of the dual-probe coating under different temperature conditions. The temperature distribution of the model wall could be measured by integrating the area within different wavelength ranges. Figure 5 ).

[0106] Example 5

[0107] 10-(4-nitrophenyl)-10-hydrophenoxazine was synthesized according to the literature (Damaceanu MD, Constantin CP, Bejan AE, et al. Heteroatom-mediated performance of dye-sensitized solar cells based on T-shaped molecules[J]. Dyes and Pigments, 2019, 166: 15-31.).

[0108] 10 mg of 10-(4-nitrophenyl)-10-hydro-phenoxazine dye and 300 mg of polyacrylonitrile were dissolved in 20 mL of N,N-dimethylformamide (DMF) (dye to polymer mass ratio 1:30). 120 mL of water was added dropwise to the solution while stirring continuously. The suspension was centrifuged and washed with water multiple times before being freeze-dried to obtain nanoparticles coated with the AIE probe. The diameter of the nanoparticles was approximately 75 nm, as measured by a Malvern laser particle size analyzer.

[0109] According to the literature (Szmacinski H, Castellano FN, Terpetschnig E, et al. Long-lifetime Ru(II) complexes for the measurement of high molecular weight protein hydrodynamics. [J]. Biochimica Et Biophysica Acta, 1998, 1383(1): 151-159.), bis(4,7-biphenyl-1,10-o-phenanthroline)(dicarboxylatedbipyridine)ruthenium dichloride [[Ru(dpp)2(dcbpy)]] was synthesized. 2+ Cl2.

[0110]

[0111] 1 mg of [[Ru(dpp)2(dcbpy)]] 2+ Cl2 was dissolved in a mixed solvent of dichloromethane and toluene to prepare a 1.0 mg / mL solution. 10 mg of AIE-NP, 100 mg of titanium dioxide nanoparticles and 50 mg of room temperature vulcanizing silicone rubber were added. The solution was then sprayed onto a glass substrate using a spray gun and cured at room temperature for 24 h to obtain a dual-probe oxygen concentration sensitive coating.

[0112] The dual-probe coating was used as a dual sensor sensitive to oxygen concentration / pressure and temperature. A model coated with the coating was cut and placed in a low-pressure chamber. The coating was excited by a 365nm LED light source, and images were captured using a color CCD camera with a 420nm long-pass filter in front of the lens. The pressure measurement range was set to 0–100 kPa, and the temperature range to 20–100℃. After the temperature reached the set value, it was held for 10 minutes before imaging. The obtained two-dimensional images under different pressure and temperature conditions were processed by channel segmentation, with the green channel being the temperature-sensitive channel and the red channel the pressure-sensitive channel. The average light intensity at the center of the sample (10 x 10 pixels) was taken as the light intensity under the set temperature and pressure conditions, obtaining the static calibration pressure and temperature results of the coating. Figure 6 )

[0113] The sample was used as a dual-sensor coating to test the surface temperature and pressure distribution under high-temperature jet conditions. The coating was excited by a 365nm LED light source and photographed by a color CCD camera. The changes in the dual-channel light intensity of the coating under alternating cold and hot jet conditions were obtained, and the surface pressure and temperature distribution of the model were then obtained based on static calibration. Figure 7 ).

[0114] Example 6

[0115] 20 mg of 10-(4-nitrophenyl)-10-hydro-phenoxazine dye and 600 mg of polyacrylonitrile were dissolved in 30 mL of N,N-dimethylformamide (DMF) (dye to polymer mass ratio 1:30). 120 mL of water was added dropwise to the solution while stirring continuously. The suspension was centrifuged and washed with water multiple times before being freeze-dried to obtain nanoparticles coated with the AIE probe. The diameter of the nanoparticles was measured to be approximately 200 nm using a Malvern laser particle size analyzer.

[0116]

[0117] 1 mg of [Ru(dpp)3]Cl2 was dissolved in 3 mL of a mixed solvent of dichloromethane and toluene. 4 mg of AIE-NP, 80 mg of silica nanoparticles with a particle size of 1 μm and 40 mg of room temperature vulcanizing silicone rubber (RTV) were added. The mixture was then sprayed onto a glass substrate using a spray gun and cured at room temperature for 24 h to obtain a dual-probe oxygen concentration / pressure and temperature-sensitive coating.

[0118] The prepared coating was fixed in a shock tube and irradiated with 455 nm blue excitation light (50 W) through a 12 cm diameter glass window. The sample was located in the low-pressure section. Gas was extracted from the shock tube using a vacuum pump to bring the low-pressure section to a pressure of 50 kPa. A plastic diaphragm isolated the low-pressure section from the high-pressure section. An air pump slowly pressurized the high-pressure section. When the pressure reached 0.378 MPa, the diaphragm ruptured, and high-pressure air rapidly entered the low-pressure section. When the airflow reached the first sensor, the oxygen partial pressure immediately increased. This pressure change generated a dynamic electrical signal, triggering a CCD camera to take a picture. The sample coating was located at the third sensor. The time it took for the airflow to reach the coating was determined based on the signal response of the third sensor. Combined with the image taken by the CCD camera, the change in fluorescence intensity of the sample coating was observed, indicating the coating's response time to the oxygen partial pressure change was approximately 50 μs. Figure 8 ).

[0119] By varying the pressures in different high and low pressure sections and selecting different diaphragms to obtain varying rupture pressures, the coating is placed in the low-pressure section glass window. The shock wave velocity under different flow field conditions is measured by utilizing the pressure change of the coating after the shock wave sweeps through it. Two-dimensional images reveal the influence of the boundary layer interference between the shock wave and the shock tube wall. Furthermore, changes in coating light intensity allow for the measurement of pressure and duration in different regions before and after the shock wave. Figure 9 ).

[0120] Example 7

[0121] 4,4'-(2,2-stilbene-1,1-diyl)bis(nitrobenzene) (TPE-2N) was synthesized according to the reference (Zhao W, He Z, Peng Q, et al. Highly sensitive switching of solid-state luminescence by controlling intersystem crossing[J]. Nature Communications, 2018, 9(1): 3044.).

[0122] A solution of tetraphenylethylene (3.32 g, 10 mmol, 100 mL DCM) was added dropwise to a mixture of nitric acid (68%, 12 mL) and glacial acetic acid (180 mL), and the mixture was stirred at room temperature (0 °C) for 30 min. A certain amount of nitric acid (68%, 12 mL) was added to the reaction solution, and the mixture was stirred for 30 min. Another portion of nitric acid (68%, 12 mL) was added to the reaction solution, and the mixture was stirred for 1.5 h. The mixture was poured into 100 mL of water and extracted with 150 mL of dichloromethane. The organic layer was washed with sodium bicarbonate solution, dried over anhydrous magnesium sulfate for 2 h, and filtered. The solvent was evaporated to remove the solvent. Finally, the residue was recrystallized from DCM / n-hexane to give yellow crystals.

[0123] 20 mg of TPE-2N dye and 200 mg of polyacrylonitrile were dissolved in 20 mL of N,N-dimethylformamide (DMF) (dye to polymer mass ratio 1:10). 120 mL of water was added dropwise to the solution while stirring continuously. The suspension was centrifuged and washed with water multiple times before being freeze-dried to obtain nanoparticles coated with the AIE probe. The diameter of the nanoparticles was measured to be approximately 50 nm using a Malvern laser particle size analyzer.

[0124] Preparation of ruthenium dichloride (2,2'-bipyridine) complex Ru(bpy)2Cl2: 0.3 mmol of ruthenium trichloride trihydrate (RuCl3·3H2O) and 0.6 mmol of 2,2'-bipyridine were added to N,N-dimethylformamide solvent at a molar ratio of n(RuCl3·3H2O):n(dcbpy) = 1:2. The reaction was carried out at 100–120 °C under a nitrogen atmosphere and stirred for 24 h. The reaction was then stopped, the insoluble matter was filtered off, the solvent was dried, and the mixture was recrystallized from acetone.

[0125] Preparation of [[Ru(bpy)3(NH2)] 2+ Cl2: React Ru(bpy)2Cl2 with 4,4'-diamino-2,2'-bipyridine at a molar ratio of 1:1, using N,N-dimethylformamide as the reaction solvent. The reaction temperature is 100-120℃, and the reaction is carried out under a nitrogen atmosphere with stirring for 24 hours. After the reaction is stopped, the insoluble matter is filtered off, and the solvent is dried.

[0126]

[0127] 1 mg of [[Ru(bpy)3(NH2)]] 2+ Cl2 was dissolved in 5 mL of dichloromethane solvent, and 5 mg of AIE-NP, 90 mg of silica nanoparticles with a particle size of 2 μm and 50 mg of room temperature vulcanizing silicone rubber (RTV) were added. The mixture was then sprayed onto a glass substrate using a spray gun and cured at room temperature for 24 h to obtain a dual-probe oxygen concentration / pressure and temperature-sensitive coating.

[0128] The sample was fixed on the test bench, and pressure and temperature changes under long-term variable gas jet conditions were measured. A 365nm LED light source was used for continuous excitation, and a time-scanning two-dimensional image of the coating's light intensity was continuously captured by a color CCD camera. Gas switching was controlled by a three-way valve, and the gas flow rate was adjusted by a rotor flow meter. The acquired images were processed by channel, and finally, the changes in pressure and temperature on the coating surface were calculated through fitting relationships. Before the above tests, the stability of the coating under continuous excitation conditions must be tested first, and the light intensity attenuation caused by continuous excitation light must be eliminated during data processing.

[0129] Figure 10 The time-scan measurement results of the light intensity change of the prepared dual-sensitive coating under continuous excitation conditions are shown.

[0130] Example 8

[0131] 20 mg of tetra(4-nitrophenyl)ethylene (TPE4N) dye and 600 mg of polyacrylonitrile (dye to polymer mass ratio 1:30) were dissolved in 30 mL of N,N-dimethylformamide (DMF) (mass concentration). Under ultrasonic conditions, the solution was rapidly injected into 120 mL of deionized water. The suspension was centrifuged and washed with water multiple times before being freeze-dried to obtain nanoparticles coated with the AIE probe. The diameter of the nanoparticles was measured to be approximately 200 nm using a Malvern laser particle size analyzer.

[0132] 1 mg of [Ru(dpp)3]Cl2 was dissolved in 3 mL of a mixed solvent of dichloromethane and toluene. 4 mg of AIE-NP, 80 mg of 1 μm silica nanoparticles, and 40 mg of room temperature vulcanizing silicone rubber (RTV) were added. The mixture was then sprayed onto a 1 cm x 1 cm aluminum sheet and cured at room temperature for 24 h to obtain sample one. For the other sample, 1 mg of [Ru(dpp)3]Cl2 was dissolved in 3 mL of a mixed solvent of dichloromethane and toluene. 1 mg of TPE4N powder, 80 mg of 1 μm silica nanoparticles, and 40 mg of room temperature vulcanizing silicone rubber (RTV) were added. The mixture was then sprayed onto another aluminum sheet and cured at room temperature to obtain sample two.

[0133]

[0134] Sample 1 and Sample 2 were placed on a heating stage, and the temperature distribution of the samples under non-uniform heating conditions was measured. The measuring equipment used was a fluorescence spectrometer, and the temperature control was achieved using a matching high-temperature sample stage. One side of each sample box was fixed to the temperature control stage. Excitation was performed using 365nm blue light, and the light intensity change was obtained through spectral integration from 450nm to 500nm. The initial temperature was 20℃, and the temperature ramp rate was set. Measurements were taken at 20℃ intervals. After heating to 120℃, the temperature was set to decrease, and measurements were taken again at 20℃ intervals. The final temperature distribution results under non-uniform heating conditions were obtained. The experimental results show that the coating prepared with uncoated TPE4N powder exhibited irreversible light intensity and temperature deviation from the set value during the heating and cooling process, while the coating with added TPE4N nanoparticles allowed for reversible temperature measurement. Figure 11 )

[0135] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. A photoluminescence oxygen concentration / pressure and temperature dual-sensitive coating, the composition comprising temperature-sensitive photoluminescence microparticles of high-molecular encapsulated aggregation-induced emission molecules (AIE) and oxygen concentration / pressure-sensitive photoluminescence molecules, wherein, The mass ratio of the temperature-sensitive photoluminescent microparticle of the polymer-encapsulated aggregation-induced emission molecule AIE and the oxygen concentration / pressure-sensitive photoluminescent molecule is 4:1-20:1; The oxygen concentration / pressure-sensitive photoluminescent molecule is a ruthenium metal complex; The ruthenium metal complex takes ruthenium as a central atom and takes a compound of bipyridyl and / or diphenyl phenanthroline with a carboxyl group and / or an amino group as a ligand; The temperature-sensitive photoluminescent microparticle of the polymer-encapsulated aggregation-induced emission molecule AIE is a polymer-encapsulated aggregation-induced emission molecule AIE microparticle; The aggregation-induced emission molecule AIE is at least one of tetraphenyl ethylene and its derivatives, triphenylamine and its derivatives, phenoxazine and its derivatives, phenothiazine and its derivatives, and carbazole and its derivatives; The polymer for encapsulating the aggregation-induced emission molecule AIE is at least one of polyethylene-vinyl alcohol copolymer, acrylonitrile-based copolymer, polyacrylate, polyurethane, polyacrylonitrile, polyamide, polyester, epoxy resin, and silicon-based amphiphilic block copolymer molecule; The photoluminescent oxygen concentration / pressure and temperature dual-sensitive coating further comprises an oxygen-permeable polymer matrix; The oxygen concentration / pressure-sensitive photoluminescent molecule is distributed in the oxygen-permeable polymer matrix in the form of chemical reaction bonding and / or physical adsorption; The photoluminescent oxygen concentration / pressure and temperature dual-sensitive coating further comprises a filler; The aggregation-induced emission molecule AIE comprises at least one of the following compounds of formula I, formula II, formula III, formula IV, and formula V: In formula I and formula II, each R1 is independently selected from at least one of -H, -NO2, C1-C6 alkyl, and a nitro-containing group, and at least one R1 represents -NO2 or a nitro-containing group; In formula III, formula IV, and formula V, each R2 is independently selected from a nitro-containing group; The ruthenium metal complex contains a cation as shown in the following structural formula: wherein R is -H, C1-C6 alkyl, -COOH, or -NH2, but at least one or two R is an amino or carboxyl functional group; or: wherein R is -H, C1-C6 alkyl, -COOH, or -NH2, but at least one or two R is an amino or carboxyl functional group; or: wherein R is -H, C1-C6 alkyl, -COOH, or -NH2, but at least one or two R is an amino or carboxyl functional group; or: wherein R is -H, C1-C6 alkyl, -COOH, or -NH2, but at least one or two R is an amino or carboxyl functional group; or a mixture thereof; The temperature-sensitive photoluminescent microparticle of the polymer-encapsulated aggregation-induced emission molecule AIE is prepared by a method comprising the following steps: 1) Dissolve or disperse the aggregation-induced emission molecule and the polymer monomer or polymer in a solvent to obtain a uniform mixed solution after stirring; 2) Prepare the polymer-encapsulated AIE microparticle from the mixed solution by at least one of solvent evaporation, emulsion polymerization, spray drying, and nano-precipitation; The mass ratio of the aggregation-induced emission molecule AIE and the polymer is 1:10-50; The solvent is at least one of N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, chloroform, ethanol, water or a mixed solvent; The diameter of the high-molecular-encapsulated AIE microparticle ranges from 50 nm to 200 nm.

2. The coating of claim 1, wherein, The oxygen-permeable high-molecular matrix is at least one of a silicon-based polymer, a fluoropropenoic acid polymer, polystyrene, and a cellulose-based polymer. The filler is at least one of silicone microspheres, titanium dioxide, silicon dioxide, mesoporous silicon dioxide, silicon dioxide aerogel, boron nitride, aluminum oxide, barium sulfate, and calcium carbonate. The particle size of the filler ranges from 30 nm to 2 μm.

3. A photoluminescence oxygen concentration / pressure and temperature dual-sensitive coating layer made of the photoluminescence oxygen concentration / pressure and temperature dual-sensitive coating material of claim 1 or 2.

4. The coating of claim 3, wherein, In the photoluminescence oxygen concentration / pressure and temperature dual-sensitive coating layer, the mass ratio of the temperature-sensitive photoluminescence microparticle and the oxygen concentration / pressure-sensitive photoluminescence molecule ranges from 4:1 to 20:1, and the mass of both accounts for 1% to 10% of the total mass of the coating layer. The oxygen-permeable high-molecular matrix accounts for 30% to 80% of the total mass of the coating layer, and the rest is the filler.

5. The photoluminescence oxygen concentration / pressure and temperature dual-sensitive coating material of claim 1 or 2 or the coating layer of claim 3 or 4 is applied in the detection of oxygen concentration, surface pressure, and temperature.

6. Use according to claim 5, characterized in that, The coating material or the coating layer is used for detecting oxygen concentration, surface pressure, or temperature alone or for simultaneously detecting oxygen concentration, surface pressure, and temperature. The detection is non-contact optical curve or two-dimensional image detection.

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