Intelligent response type engine airtightness detection leakage test liquid and preparation method thereof

Abstract

The invention provides an intelligent response type engine airtightness detection leakage test liquid and a preparation method thereof. The leakage testing liquid for air tightness detection is prepared from the following components in parts by weight: 88 to 92 parts of a component A, 6 to 8 parts of a component B, 1 to 3 parts of a component C and 0.5 to 1.5 parts of a component D, wherein the component A comprises deionized water, xanthan gum, konjac glucomannan and a 5% poly (N-isopropylacrylamide) aqueous solution, and is used as a bionic self-repairing solvent; the component B comprises a dopamine-phytic acid composite solution and a beta-cyclodextrin loaded benzotriazole nanocapsule dispersion liquid with the solid content of 10%, and is used as an anti-rust system; the component C comprises locust bean gum, soyasaponin and pH response type porphyrin derivative fluorescent nanoparticle dispersion liquid and serves as a bionic foaming and tracing system, and the component D comprises molybdenum disulfide nanosheet dispersion liquid and serves as an auxiliary functional additive. Aiming at the problems in the prior art, the invention designs the novel engine air tightness detection leakage testing liquid which can simultaneously take the self-repairing performance, the anti-rust performance and the tracing precision into account.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine manufacturing and maintenance, and in particular relates to an intelligent response type engine air tightness detection leakage test liquid and a preparation method thereof. Background Art

[0002] In modern engine manufacturing and maintenance, complete engine airtightness testing, a core component for ensuring engine performance and reliability, places increasingly stringent demands on leak detection fluids. Currently, the industry generally uses commercial leak detection fluids for testing. These fluids contain a fluorescent agent or a specialized synthetic foaming agent based on alkyl sulfonates, supplemented with a small amount of rust inhibitor and deionized water. While these leak detection fluids meet basic testing requirements, they present numerous technical bottlenecks that are difficult to ignore, severely hindering industry development.

[0003] (1) Lack of self-healing ability and limitations in leak plugging: Traditional leak test fluids are usually water-based or oil-based solutions with low viscosity and lack of environmental response mechanisms, making them ineffective in plugging tiny leaks. When the leak is subject to pressure fluctuations, the liquid is easily lost, leading to misjudgment of the leak point. In addition, the viscosity of conventional solvents decreases in low-temperature environments, further reducing detection reliability.

[0004] (2) Metal rust and corrosion hazards: If the water-based leak test solution does not contain a rust prevention system, metal parts are easily corroded by water during the test process, causing rust. While adding traditional rust inhibitors such as chromate is effective, there is a risk of heavy metal pollution. Some patents use nano zinc oxide for rust prevention, but the dispersion stability is poor and it is prone to agglomeration and failure during long-term storage.

[0005] (3) Insufficient tracing sensitivity and environmental adaptability: Existing tracing methods mainly rely on methylene blue dye or ultraviolet fluorescent agent, which have the following defects: ① Engine fuel leakage causes acidification of the test fluid and other pH fluctuations, which can cause the dye to fade; ② Under complex working conditions with interference from oil or metal debris, the fluorescence signal is easily attenuated.

[0006] (4) Single function and poor process compatibility: Traditional leak test fluids only have a single detection function and lack auxiliary protection such as lubrication or anti-wear for engine parts.

[0007] Therefore, developing a new engine air tightness detection leak test fluid that takes into account self-repairing performance, rust prevention performance and tracing accuracy is an urgent problem to be solved by technical personnel in this field. Summary of the Invention

[0008] In response to the above technical problems, the present invention aims to provide an intelligent responsive engine airtightness detection leak test liquid. The intelligent responsive engine airtightness detection leak test liquid comprises, by weight, 88-92 parts of component A, 6-8 parts of component B, 1-3 parts of component C, and 0.5-1.5 parts of component D.

[0009] Wherein, the component A includes deionized water, xanthan gum, konjac glucomannan, and 5% poly N-isopropylacrylamide (PNIPAM) aqueous solution as a biomimetic self-repairing solvent;

[0010] The component B includes a dopamine-phytic acid composite solution and a 10% solid content beta-cyclodextrin loaded benzotriazole (BTA) nanocapsule dispersion as an anti-rust system;

[0011] The component C includes locust bean gum, soybean saponin, and pH-responsive porphyrin derivative fluorescent nanoparticle dispersion, which serves as a biomimetic foaming and tracing system:

[0012] The component D includes a dispersion of molybdenum disulfide nanosheets as an auxiliary functional additive.

[0013] In a preferred embodiment, the total weight of component A, component B, component C and component D is 100 parts.

[0014] In a preferred embodiment, in component A, the mass ratio of deionized water, xanthan gum, konjac glucomannan, and 5% poly N-isopropylacrylamide (PNIPAM) aqueous solution is (352-396):(15.2-17.6):(9-11):(19-22).

[0015] In a preferred embodiment, the method for preparing the 5% poly (N-isopropylacrylamide) aqueous solution comprises the following steps:

[0016] 50 g of N-isopropylacrylamide monomer and 0.4-0.6 g of ammonium persulfate were weighed and dissolved in 950 mL of deionized water. The mixture was stirred at 100-200 rpm in a constant temperature water bath at 50-60°C under a protective atmosphere for 3-4 hours. After the reaction, the solution was filtered through a 0.45 μm microporous filter membrane to obtain a PNIPAM aqueous solution with a solid content of 5%.

[0017] In a preferred embodiment, in component B, the mass ratio of the dopamine-phytic acid composite solution to the 10% solid content β-cyclodextrin-loaded benzotriazole (BTA) nanocapsule dispersion is (1.8-2.2):(2.7-3.3).

[0018] In a preferred embodiment, the preparation method of the dopamine-phytic acid complex solution comprises the following steps: 1: (1-3) of dopamine and phytic acid are weighed by mass ratio, respectively dispersed in deionized water, stirred and dissolved at room temperature to obtain dopamine solution and phytic acid solution; the obtained dopamine solution and phytic acid solution are mixed, stirred uniformly, sodium hydroxide solution is added to adjust the pH of the system to 7-8, and the reaction is stirred at 100-300 rpm in a constant temperature water bath at 30°C for 1-3 hours; after the reaction is completed, it is filtered through a 0.45 μm microporous filter membrane to obtain the product; preferably, the concentration of sodium hydroxide solution is 0.5-1.5 mol / L.

[0019] In a preferred embodiment, the preparation method of the 10% solid content β-cyclodextrin loaded benzotriazole nanocapsule dispersion solution comprises the following steps:

[0020] 1-3 g of β-cyclodextrin is dissolved in 100 mL of deionized water, and stirred in a 50-60°C water bath until completely dissolved; 0.1-0.3 g of benzotriazole is dissolved in 15 mL of ethanol, and the obtained benzotriazole ethanol solution is added dropwise into the β-cyclodextrin solution, and stirred at 35-45°C for 5-6 hours to obtain a transparent inclusion liquid;

[0021] The inclusion liquid is slowly added dropwise into 250 mL of ice water at a stirring speed of 800-1000 rpm, and stirring is continued for 1 hour after the addition is completed; the obtained turbid liquid is transferred to a centrifuge tube, high-speed centrifugation is performed, the supernatant is discarded, and the precipitate is collected and washed with ethanol-water mixture and deionized water in sequence;

[0022] The washed precipitate is dispersed in 20 mL of deionized water, 0.1 g of Tween-80 is added, and ultrasonic dispersion is performed to obtain a nanocapsule dispersion solution with a solid content of about 10%.

[0023] In a preferred embodiment, in component C, the mass ratio of the locust bean gum, soybean saponin, and pH-responsive porphyrin derivative fluorescent nanoparticle dispersion solution is (5.4-6.6):(3.6-4.4):(0.8-1.2).

[0024] In a preferred embodiment, the preparation of the pH-responsive porphyrin derivative fluorescent nanoparticle dispersion solution comprises the following steps:

[0025] Water phase preparation: 0.4-0.6 g of porphyrin derivative monomer, 0.05 g of potassium persulfate, and 0.1 g of acrylic acid or methacrylic acid are added to 100 mL of deionized water, and stirred uniformly to form a water phase;

[0026] Oil phase preparation: In another container, 1.5-2.5 g of methyl methacrylate and 0.2 g of sodium dodecyl sulfate are mixed and ultrasonically dispersed to form an oil phase;

[0027] Polymerization reaction: slowly drip the oil phase into the water phase, stir and emulsify, then raise the temperature to 65-70℃ under protective atmosphere, stir and polymerize to form nanoparticles;

[0028] Purification treatment: After the reaction is completed, the product is dialyzed in ethanol to remove unreacted monomers and impurities, and then dispersed with deionized water to prepare a pH-responsive porphyrin derivative fluorescent nanoparticle dispersion with a concentration of 1% (w / v).

[0029] In a preferred embodiment, the preparation of a molybdenum disulfide nanosheet dispersion comprises the following steps: adding 0.3-0.8 g of sodium molybdate, 1-1.5 g of thiourea, and 0.6-1.0 g of polyvinyl pyrrolidone to 50 mL of deionized water, stirring to dissolve, then adding 10 mL of ethanol to mix, transferring to a 100 mL polytetrafluoroethylene-lined autoclave, heating to 160-200 ° C at a rate of 3-7 ° C / min and reacting at a constant temperature for 18-24 hours; cooling to room temperature, centrifuging at 6000-8000 rpm for 5-15 minutes, washing with an ethanol-water mixture, dispersing the product in 20 mL of polyethylene glycol-400 (PEG-400), and ultrasonicating until uniform to obtain a molybdenum disulfide nanosheet dispersion with a concentration of 3% (w / v), a lateral size of 100-200 nm, and an average of 4-6 layers.

[0030] Another object of the present invention is to provide a method for preparing any one of the above-mentioned intelligent response type engine air tightness detection leakage test liquids, characterized in that it comprises the following steps:

[0031] S1 prepare the components A, B, C and D respectively according to their weight proportions;

[0032] S2: Add deionized water to the reactor, heat to 40-50°C, add xanthan gum and konjac glucomannan in sequence, and stir at 300-400 rpm for 30-40 minutes;

[0033] S3 cools down to room temperature, adds dopamine-phytic acid composite solution and molybdenum disulfide nanosheet dispersion, and stirs until uniform;

[0034] S4: Add 5% poly (N-isopropylacrylamide) (PNIPAM) aqueous solution, locust bean gum, and soybean saponin, and stir at 500-600 rpm for 5-15 min;

[0035] S5: adding 10% solid content of β-cyclodextrin loaded benzotriazole (BTA) nanocapsule dispersion and pH-responsive porphyrin derivative fluorescent nanoparticle dispersion, stirring at 100-200 rpm for 20-30 minutes to obtain.

[0036] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0037] 1. The present invention constructs a thermosensitive-viscoelastic dual-response self-healing system by compounding a 5% poly N-isopropylacrylamide (PNIPAM) aqueous solution in component A with xanthan gum and konjac glucomannan. The lower critical solution temperature of PNIPAM is about 32°C. When the leak test liquid contacts the high-speed airflow or friction heat-generating area at the leak hole, the local temperature rise triggers the contraction of the PNIPAM chain segments, forming a network gel with the natural polymer, which can achieve dynamic blocking of tiny leak holes of 5-50μm. Experimental data show that the blocking response time of this system at the leak hole is less than 10s. Compared with traditional water-based leak test liquids without self-healing function, the misjudgment rate of leak points can be greatly reduced, and the viscoelastic properties can be maintained in the temperature range of -20°C to 80°C (viscosity fluctuation ≤15%), solving the problem of detection failure in low temperature environments.

[0038] 2. In the present invention, the dopamine-phytic acid composite solution in component B and the β-cyclodextrin-loaded benzotriazole nanocapsules form a dual anti-rust mechanism of "in-situ passivation-corrosion inhibitor controlled release": dopamine oxidizes and self-polymerizes under pH 7-8 to form a polydopamine film, which covalently bonds to the metal surface through the catechol group to form the first protective layer; phytic acid, as a polyhydroxyphosphate, can react with Fe 2+ It forms a stable chelate to inhibit electrochemical corrosion; β-CD nanocapsules release BTA in response to pH, forming a coordination-type protective film on the metal surface, extending the anti-rust period to more than twice that of the traditional chromate system.

[0039] 3. In this invention, the pH-responsive porphyrin derivative fluorescent nanoparticles in component C exhibit a fluorescence intensity change rate exceeding 80% within the pH range of 4-8. When the leak test fluid seeps into the leak hole and contacts fuel or coolant, the fluorescence signal changes significantly. Combined with UV illumination, this allows for millimeter-level localization of the leak. Compared to traditional fluorescent dyes, these nanoparticles, produced through emulsion polymerization, have a controlled particle size of 50-80 nm, exhibit high dispersion stability, show no precipitation after storage at 4°C for six months, and exhibit strong resistance to oil contamination.

[0040] 4. In the present invention, the auxiliary functional additive provides excellent anti-wear performance. The molybdenum disulfide nanosheets of component D are evenly dispersed in the leak test fluid and can fill the micro-pits on the metal surface during the detection process, reducing the friction coefficient and effectively reducing component wear.

[0041] 5. The leak test solution provided by the present invention does not contain volatile organic compounds. Moreover, the water-based system is biodegradable and the anti-rust system does not contain heavy metals, which has the beneficial effect of being green and environmentally friendly. In addition, the raw materials of each component of the present invention are low in cost, making it particularly suitable for large-scale industrial production.

[0042] 6. The preparation method provided by the present invention is simple and easy to operate, and the preparation of each component does not require complex equipment such as high-pressure homogenization and freeze-drying. Furthermore, the prepared intelligent responsive engine air tightness detection leak test fluid can be prepared with different viscosities by adjusting the ratio of the temperature-sensitive polymer to the thickener in component A. This allows for adaptation to different operating conditions, such as aircraft engines (high viscosity) and automotive engines (medium viscosity), and has a wide range of applications. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with specific embodiments. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0044] The technical solution of this application is described in detail below through specific embodiments:

[0045] Unless otherwise specified, the technical means used in the present invention are conventional means well known to those skilled in the art. The various raw materials, reagents, instruments, and equipment used in the present invention can be purchased commercially or prepared by existing methods. Unless otherwise specified, all reagents used in the present invention are of analytical grade. Unless otherwise specified, the room temperature in the present invention is 25±2°C.

[0046] In the present invention, parts by weight may be weight units known in the art such as μg, mg, g, kg, etc., or multiples thereof, such as 1 / 10, 1 / 100, 10 times, 100 times, etc.

[0047] Example 1

[0048] Preparation of a 5% aqueous solution of poly (N-isopropylacrylamide) of component A comprises the following steps:

[0049] 50 g of N-isopropylacrylamide (NIPAM) monomer and 0.5 g of ammonium persulfate initiator were weighed and dissolved in 950 mL of deionized water. Under nitrogen protection, the mixture was stirred at 200 rpm in a constant temperature water bath at 60°C for 4 hours to initiate free radical polymerization. After the reaction, the solution was filtered through a 0.45 μm microporous filter membrane to obtain a PNIPAM aqueous solution with a solid content of 5%.

[0050] Example 2

[0051] The preparation of the dopamine-phytic acid composite solution of component B comprises the following steps:

[0052] Weigh 10 g of analytical grade dopamine (≥98%) and 20 g of industrial grade phytic acid (≥70%), disperse them in 80 mL of deionized water, and stir at 150 rpm at 25° C. to dissolve them to obtain a dopamine solution and a phytic acid solution; slowly pour the dopamine solution into the phytic acid solution, stir evenly at 300 rpm, add 1 mol / L sodium hydroxide solution to slowly adjust the pH of the system to 7-8 (control the system temperature ≤30° C.); then, transfer to a 30° C. constant temperature water bath, stir at 200 rpm for 2 hours; after the reaction, filter through a 0.45 μm microporous filter membrane, and seal the filtrate and store it in a dark environment at 4° C.

[0053] Example 3

[0054] Preparation of a 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion of component B comprises the following steps:

[0055] Dissolve 2g of β-cyclodextrin in 100mL of deionized water and stir in a 60°C waterbath for 40 minutes until completely dissolved. Dissolve 0.2g of benzotriazole in 15mL of ethanol. Add the resulting benzotriazole solution dropwise to the β-CD solution and stir at 40°C for 6 hours to obtain a transparent inclusion solution. The inclusion solution was slowly added dropwise to 250mL of ice water at a rate of 5mL / min with a stirring speed of 1000rpm. Stir at 1000rpm for 1 hour after the addition was complete. The resulting turbid solution was transferred to a centrifuge tube and centrifuged at 10,000rpm for 15 minutes. The supernatant was discarded. The precipitate was collected and washed once with an ethanol-water mixture (1:1 volume ratio) and then twice with deionized water. The washed precipitate was dispersed in 20mL of deionized water, 0.1g of Tween-80 was added, and sonication was performed at 200W and 20kHz for 20 minutes to obtain a nanocapsule dispersion with a solids content of approximately 10%.

[0056] Example 4

[0057] The preparation of the pH-responsive porphyrin derivative fluorescent nanoparticle dispersion of component C comprises the following steps:

[0058] Preparation of S1 aqueous phase: Add 0.5 g analytically pure tetrakis(4-aminophenyl)porphyrin (TAPP), 0.05 g potassium persulfate, and 0.1 g chemically pure acrylic acid into 100 mL deionized water and stir at 200 rpm for 30 min at room temperature until completely dissolved.

[0059] Preparation of S2 oil phase: 2 g of methyl methacrylate and 0.2 g of sodium lauryl sulfate were mixed and dispersed under 40 kHz ultrasonic conditions for 5 min to form a uniform emulsion.

[0060] S3 polymerization reaction: the oil phase was added dropwise to the water phase at a rate of 2 mL / min, and emulsified at 60°C and 300 rpm for 30 min; then nitrogen was introduced at a flow rate of 50 mL / min for 30 min to deoxygenate, the temperature was raised to 70°C, and the reaction was carried out at 200 rpm for 6 hours.

[0061] S4 Purification: After cooling, the reaction solution was transferred to a dialysis bag with a molecular weight cutoff of 3500 Da and dialyzed against anhydrous ethanol for 48 hours (ethanol was changed every 8 hours) to remove unreacted monomers. Finally, the volume was adjusted to 100 mL with deionized water to produce a 1% (w / v) nanoparticle dispersion. The resulting dispersion had a particle size of 50-80 nm and exhibited significant fluorescence intensity changes within the pH range of 4-8, making it suitable for leak detection.

[0062] Example 5

[0063] The preparation of the molybdenum disulfide nanosheet dispersion of component D comprises the following steps:

[0064] 0.5 g of sodium molybdate, 1.2 g of thiourea, and 0.8 g of polyvinylpyrrolidone were added to 50 mL of deionized water, magnetically stirred at 60°C for 30 min to dissolve, and then 10 mL of ethanol was added and mixed. The mixture was transferred to a 100 mL polytetrafluoroethylene-lined autoclave and heated to 180°C at a rate of 5°C / min for 24 hours. After cooling, the mixture was centrifuged at 8000 rpm for 15 min and washed three times with an ethanol-water mixture (volume ratio of 1:1). Finally, the product was dispersed in 20 mL of polyethylene glycol-400 (PEG-400) and ultrasonicated at 60°C for 30 min (power 300 W) to obtain a 3% (w / v) molybdenum disulfide nanosheet dispersion.

[0065] Example 6

[0066] An intelligent response type engine air tightness detection leak test liquid, the formula of which is:

[0067] Component A: 90 parts (370 g deionized water, 16 g xanthan gum, 10 g konjac glucomannan, and 20 g of the 5% poly (N-isopropylacrylamide) aqueous solution prepared in Example 1);

[0068] Component B: 7 parts (3 g of the dopamine-phytic acid composite solution prepared in Example 2, 4 g of the 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion prepared in Example 3);

[0069] Component C: 2 parts (1.08 g locust bean gum, 0.72 g soybean saponin, and 0.2 g pH-responsive porphyrin derivative fluorescent nanoparticle dispersion prepared in Example 4);

[0070] Component D: 1 part of the molybdenum disulfide nanosheet dispersion prepared in Example 5.

[0071] The preparation method thereof comprises:

[0072] S1 prepare the components A, B, C and D respectively according to their weight proportions;

[0073] S2: Add deionized water of component A to the reactor, heat to 40°C, add xanthan gum of component A and konjac glucomannan of component A in sequence, and stir at 300 rpm for 40 min;

[0074] S3 cools the mixture to room temperature, adds the dopamine-phytic acid composite solution of component B and the molybdenum disulfide nanosheet dispersion of component D, and stirs until uniform;

[0075] S4 Add 5% poly (N-isopropylacrylamide) aqueous solution of component A, locust bean gum of component C, and soybean saponin of component C, and stir at 600 rpm for 5 min;

[0076] S5: add 10% solid content β-cyclodextrin loaded benzotriazole nanocapsule dispersion of component B and pH-responsive porphyrin derivative fluorescent nanoparticle dispersion of component C, and stir at 100 rpm for 20 minutes to obtain.

[0077] The performance test of the intelligent response engine air tightness detection liquid prepared in this embodiment was carried out, and the results were as follows:

[0078] (1) Self-repair performance test:

[0079] Experimental method: A 316L stainless steel test plate was used, and a through-hole with a diameter of 50 μm was machined on the surface to simulate a leak. Air was used as the medium, and a pressure pump was used to apply 0.5 MPa pressure to one side of the test plate to simulate the internal pressure of the engine. The prepared leak test liquid was evenly applied to the leak hole side of the test plate, and a high-speed camera was used to record the gelation and sealing time of the leak test liquid at the leak hole. At the same time, a rheometer (shear rate 10s -1 ) Determine the viscosity of the leak test liquid at 25℃ and -20℃, and test each sample 3 times to take the average value.

[0080] Test results: 50μm leak plugging time 8s, viscosity 850cP (25℃).

[0081] (2) Anti-rust performance test:

[0082] Experimental method: A Q235 carbon steel sheet (50mm×25mm×2mm) was polished to a mirror surface with sandpaper, degreased with acetone, and immersed in the prepared leak test solution for 24 hours; according to the GB / T10125-2021 standard, the specimen was placed in a salt spray chamber, with 5% NaCl solution as the spray medium, the temperature was 35°C, and the spray was continuous.

[0083] Test result: no rust after 72 hours of salt spray.

[0084] (3) Tracer performance test

[0085] Experimental method: Use a fluorescence spectrophotometer with an excitation wavelength of 400 nm and an emission wavelength of 580 nm to measure the fluorescence intensity of the prepared leak test solution in pH 4 buffer (0.1 mol / L citric acid-hydrochloric acid).

[0086] Test results: Fluorescence intensity 1300 a.u. at pH = 4.

[0087] (4) Anti-wear performance test:

[0088] Experimental method: A ball-on-disc friction and wear tester was used, with the upper specimen being a GCr15 steel ball (6 mm in diameter) and the lower specimen being a 45# steel disc (20 mm in diameter); the load was 10 N, the rotation speed was 200 rpm, and the test time was 30 min; the prepared leak test fluid was used as a lubricating medium and applied to the contact interface; and the friction coefficient was recorded in real time.

[0089] Test results: friction coefficient 0.32.

[0090] Example 7

[0091] An intelligent response type engine air tightness detection leak test liquid, the formula of which is:

[0092] Component A: 90 parts (370 g deionized water, 16 g xanthan gum, 10 g konjac glucomannan, and 20 g of the 5% poly (N-isopropylacrylamide) aqueous solution prepared in Example 1);

[0093] Component B: 7 parts (3 g of the dopamine-phytic acid composite solution prepared in Example 2, 4 g of the 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion prepared in Example 3);

[0094] Component C: 2 parts (1.32 g locust bean gum, 0.88 g soybean saponin, and 0.2 g pH-responsive porphyrin derivative fluorescent nanoparticle dispersion prepared in Example 4);

[0095] Component D: 1 part of the molybdenum disulfide nanosheet dispersion prepared in Example 5.

[0096] The preparation method and performance test method are consistent with Example 6, and the results are:

[0097] 50μm leak plugging time 8.5s, viscosity 900cP (25℃); no rust after 72h of salt spray; fluorescence intensity 1250a.u. at pH=4; friction coefficient 0.32.

[0098] Example 8

[0099] An intelligent response type engine air tightness detection leak test liquid, the formula of which is:

[0100] Component A: 90 parts (370 g deionized water, 16 g xanthan gum, 10 g konjac glucomannan, and 20 g of the 5% poly (N-isopropylacrylamide) aqueous solution prepared in Example 1);

[0101] Component B: 7 parts (3 g of the dopamine-phytic acid composite solution prepared in Example 2, 4 g of the 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion prepared in Example 3);

[0102] Component C: 1.5 parts (0.81 g locust bean gum, 0.54 g soybean saponin, and 0.15 g pH-responsive porphyrin derivative fluorescent nanoparticle dispersion prepared in Example 4);

[0103] Component D: 1 part of the molybdenum disulfide nanosheet dispersion prepared in Example 5.

[0104] The preparation method and performance test method are consistent with Example 6, and the results are:

[0105] 50μm leak sealing time 8s; no rust after 72h in salt spray; fluorescence intensity 1000a.u. at pH=4; friction coefficient 0.32.

[0106] Example 9

[0107] An intelligent response type engine air tightness detection leak test liquid, the formula of which is:

[0108] Component A: 90 parts (370 g deionized water, 16 g xanthan gum, 10 g konjac glucomannan, and 20 g of the 5% poly (N-isopropylacrylamide) aqueous solution prepared in Example 1);

[0109] Component B: 6 parts (2.4 g of the dopamine-phytic acid composite solution prepared in Example 2, 3.6 g of the 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion prepared in Example 3);

[0110] Component C: 2 parts (1.32 g locust bean gum, 0.82 g soybean saponin, and 0.2 g pH-responsive porphyrin derivative fluorescent nanoparticle dispersion prepared in Example 4);

[0111] Component D: 1 part of the molybdenum disulfide nanosheet dispersion prepared in Example 5.

[0112] The preparation method and performance test method are consistent with Example 6, and the results are:

[0113] The plugging time for a 50μm leak is 8.2s; there is no rust after 60 hours of salt spray; the fluorescence intensity is 1300 a.u. at pH = 4; and the friction coefficient is 0.32.

[0114] Example 10

[0115] An intelligent response type engine air tightness test solution, the formula is:

[0116] Component A: 90 parts (deionized water 368 g, xanthan gum 16 g, konjac glucomannan 10 g and 5% poly-N-isopropyl acrylamide aqueous solution prepared in Example 1 22 g);

[0117] Component B: 7 parts (3 g dopamine-phytic acid complex solution prepared in Example 2, 4 g 10% solid content of β-cyclodextrin loaded benzotriazole nanocapsule dispersion prepared in Example 3);

[0118] Component C: 2 parts (1.32 g locust bean gum, 0.82 g soybean saponin and 0.2 g pH responsive porphyrin derivative fluorescent nanoparticle dispersion prepared in Example 4);

[0119] Component D: 1 part of molybdenum disulfide nanosheet dispersion prepared in Example 5.

[0120] The preparation method, performance test method and Example 6 are consistent, and the results are:

[0121] The 50 μm leak hole plugging time is 6 s; there is no rust after salt spray for 72 h; the fluorescence intensity at pH = 4 is 1300 a.u.; and the friction coefficient is 0.32.

[0122] Example 11

[0123] An intelligent response type engine air tightness test solution, the formula is:

[0124] Component A: 90 parts (deionized water 370 g, xanthan gum 16 g, konjac glucomannan 10 g and 5% poly-N-isopropyl acrylamide aqueous solution prepared in Example 1 20 g);

[0125] Component B: 7 parts (3 g dopamine-phytic acid complex solution prepared in Example 2, 4 g 10% solid content of β-cyclodextrin loaded benzotriazole nanocapsule dispersion prepared in Example 3);

[0126] Component C: 2 parts (1.32 g locust bean gum, 0.82 g soybean saponin and 0.2 g pH responsive porphyrin derivative fluorescent nanoparticle dispersion prepared in Example 4);

[0127] Component D: 0.8 parts of molybdenum disulfide nanosheet dispersion prepared in Example 5.

[0128] The preparation method, performance test method and Example 6 are consistent, and the results are:

[0129] 50μm leak sealing time 8s; no rust after 72h in salt spray; fluorescence intensity 1300a.u. at pH=4; friction coefficient 0.34.

[0130] Example 12

[0131] An intelligent response type engine air tightness detection leak test liquid, the formula of which is:

[0132] Component A: 88 parts (370 g deionized water, 16 g xanthan gum, 10 g konjac glucomannan, and 20 g of the 5% poly (N-isopropylacrylamide) aqueous solution prepared in Example 1);

[0133] Component B: 8 parts (3.2 g of the dopamine-phytic acid composite solution prepared in Example 2, 4.8 g of the 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion prepared in Example 3);

[0134] Component C: 3 parts (1.62 g locust bean gum, 1.08 g soybean saponin, and 0.3 g pH-responsive porphyrin derivative fluorescent nanoparticle dispersion prepared in Example 4);

[0135] Component D: 1 part of the molybdenum disulfide nanosheet dispersion prepared in Example 5.

[0136] The preparation method and performance test method are consistent with Example 6, and the results are:

[0137] 50μm leak sealing time 9s; no rust after 120h of salt spray; fluorescence intensity 1600a.u. at pH=4; friction coefficient 0.32.

[0138] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An intelligent response engine air tightness detection leak test liquid, characterized in that: The intelligent response engine air tightness detection leak test liquid comprises, by weight: 88-92 parts of component A, 6-8 parts of component B, 1-3 parts of component C and 0.5-1.5 parts of component D; Wherein, the component A includes deionized water, xanthan gum, konjac glucomannan, and 5% poly N-isopropylacrylamide aqueous solution as a bionic self-repairing solvent; The component B includes a dopamine-phytic acid composite solution and a 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion as an anti-rust system; The component C includes locust bean gum, soybean saponin, and pH-responsive porphyrin derivative fluorescent nanoparticle dispersion, which serves as a biomimetic foaming and tracing system: The component D includes a dispersion of molybdenum disulfide nanosheets as an auxiliary functional additive.

2. The intelligent response engine air tightness detection leak test liquid as claimed in claim 1, characterized in that: In component A, the mass ratio of the deionized water, xanthan gum, konjac glucomannan, and 5% poly (N-isopropylacrylamide) aqueous solution is (352-396): (15.2-17.6): (9-11): (19-22).

3. The intelligent response engine air tightness detection leak test liquid as claimed in claim 2, characterized in that: The preparation method of the 5% poly (N-isopropylacrylamide) aqueous solution comprises the following steps: Weigh 50 g of N-isopropylacrylamide monomer and 0.4-0.6 g of ammonium persulfate, dissolve them in 950 mL of deionized water, and stir at 100-200 rpm in a constant temperature water bath at 50-60° C. under a protective atmosphere for 3-4 hours. After the reaction is completed, filter the solution through a 0.45 μm microporous filter membrane to obtain the product.

4. The intelligent response engine air tightness detection leak test liquid as claimed in claim 1, characterized in that: In component B, the mass ratio of the dopamine-phytic acid composite solution to the 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion is (1.8-2.2):(2.7-3.3).

5. The intelligent response engine air tightness detection leak test liquid as claimed in claim 4, characterized in that: The preparation method of the dopamine-phytic acid composite solution comprises the following steps: dopamine and phytic acid are weighed in a mass ratio of 1:(1-3), dispersed in deionized water, and dissolved by stirring at room temperature to obtain a dopamine solution and a phytic acid solution; the dopamine solution and the phytic acid solution are mixed and stirred evenly, a sodium hydroxide solution is added to adjust the pH of the system to 7-8, and the mixture is stirred at 100-300 rpm in a constant temperature water bath at 30°C for 1-3 hours; and after the reaction is completed, the mixture is filtered through a 0.45 μm microporous filter membrane to obtain the composite solution.

6. The intelligent response engine air tightness detection leak test liquid as claimed in claim 4, characterized in that: The preparation method of the 10% solid content β-cyclodextrin-loaded benzotriazole nanocapsule dispersion comprises the following steps: Dissolve 1-3 g of β-cyclodextrin in 100 mL of deionized water and stir in a 50-60°C water bath until completely dissolved; dissolve 0.1-0.3 g of benzotriazole in 15 mL of ethanol, add the resulting benzotriazole ethanol solution dropwise to the β-cyclodextrin solution, and stir at a constant temperature of 35-45°C for 5-6 hours to obtain a transparent inclusion solution; The inclusion solution was slowly added dropwise to 250 mL of ice water at a stirring speed of 800-1000 rpm. After the addition was complete, stirring was continued for 1 hour. The resulting turbid solution was transferred to a centrifuge tube and centrifuged at high speed. The supernatant was discarded and the precipitate was collected and washed with an ethanol-water mixture and then deionized water. The washed precipitate was dispersed in 20 mL of deionized water, 0.1 g of Tween-80 was added, and ultrasonic dispersion was performed to prepare a nanocapsule dispersion with a solid content of about 10%.

7. The intelligent response engine air tightness detection leak test liquid as claimed in claim 1, characterized in that: In component C, the mass ratio of the locust bean gum, soybean saponin, and pH-responsive porphyrin derivative fluorescent nanoparticle dispersion is (5.4-6.6):(3.6-4.4):(0.8-1.2).

8. The intelligent response engine air tightness detection leak test liquid as claimed in claim 7, characterized in that: The preparation of the pH-responsive porphyrin derivative fluorescent nanoparticle dispersion comprises the following steps: Preparation of aqueous phase: Add 0.4-0.6 g of porphyrin derivative monomer, 0.05 g of potassium persulfate, and 0.1 g of acrylic acid or methacrylic acid to 100 mL of deionized water and stir evenly to form an aqueous phase; Preparation of oil phase: In another container, mix 1.5-2.5 g of methyl methacrylate and 0.2 g of sodium lauryl sulfate and disperse by ultrasonication to form an oil phase; Polymerization reaction: slowly drip the oil phase into the water phase, stir and emulsify, then raise the temperature to 65-70℃ under protective atmosphere, stir and polymerize to form nanoparticles; Purification treatment: After the reaction is completed, the product is dialyzed in ethanol to remove unreacted monomers and impurities, and then dispersed with deionized water to prepare a pH-responsive porphyrin derivative fluorescent nanoparticle dispersion with a concentration of 1%.

9. The intelligent response engine air tightness detection leak test liquid as claimed in claim 1, characterized in that: The preparation of a molybdenum disulfide nanosheet dispersion includes the following steps: adding 0.3-0.8g of sodium molybdate, 1-1.5g of thiourea, and 0.6-1.0g of polyvinyl pyrrolidone to 50mL of deionized water, stirring to dissolve, then adding 10mL of ethanol and mixing evenly, transferring to a polytetrafluoroethylene-lined autoclave, heating to 160-200°C at a heating rate of 3-7°C / min and reacting at a constant temperature for 18-24 hours; cooling to room temperature, centrifuging at 6000-8000rpm for 5-15 minutes, washing, dispersing the product in 20mL of polyethylene glycol-400, and ultrasonicating until uniform, to prepare a molybdenum disulfide nanosheet dispersion with a concentration of 3%.

10. The method for preparing the intelligent response type engine air tightness detection leak test liquid according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1 prepare the components A, B, C and D respectively according to their weight proportions; S2: Add deionized water to the reactor, heat to 40-50°C, add xanthan gum and konjac glucomannan in sequence, and stir at 300-400 rpm for 30-40 minutes; S3 cools down to room temperature, adds dopamine-phytic acid composite solution and molybdenum disulfide nanosheet dispersion, and stirs until uniform; S4: Add 5% poly (N-isopropylacrylamide) aqueous solution, locust bean gum and soybean saponin, and stir at 500-600 rpm for 5-15 minutes; S5: adding 10% solid content of β-cyclodextrin loaded benzotriazole nanocapsule dispersion and pH-responsive porphyrin derivative fluorescent nanoparticle dispersion, stirring at 100-200 rpm for 20-30 minutes to obtain.