Preparation method of aircraft anti-icing fluid containing gram-level water-soluble aggregation-induced emission polymer
By adding a gram-level water-soluble aggregation-induced light-emitting polymer to aircraft anti-icing fluid and utilizing its photoluminescence behavior, the problem of subjective judgment of anti-icing effect caused by insufficient light at night is solved, realizing convenient and accurate visual detection of icing and enhancing the detection capability of anti-icing fluid.
Patent Information
- Application Number
- CN202511486950.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-17
- Publication Date
- 2026-01-16
AI Technical Summary
In existing aircraft de-icing technologies, it is difficult to accurately judge the anti-icing effect on the aircraft surface at night or in low light conditions, which poses a safety hazard. Furthermore, existing aggregation-induced emission materials have problems such as decreased viscosity, short emission duration, and the need for continuous ultraviolet light excitation when used in anti-icing fluids.
A gram-level water-soluble aggregation-induced emission polymer (AIE) material is synthesized and added to the anti-icing fluid. The photoluminescence behavior is used to achieve visual detection of icing, combined with UV light source for auxiliary inspection.
It enables rapid and accurate detection of secondary icing on aircraft surfaces in low-temperature climates, enhancing the detection function of anti-icing fluid without affecting the viscosity and anti-icing time of the anti-icing fluid.
Smart Images
Figure CN121343556A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aircraft de-icing and anti-icing, specifically relating to a method for preparing an aircraft anti-icing fluid containing a gram-level water-soluble aggregation-induced light-emitting polymer. Background Technology
[0003] To ensure aviation safety, domestic and international organizations mandate that aircraft with icing or snow accumulation undergo effective and thorough de-icing and anti-icing operations before being allowed to perform flight missions. Currently, de-icing and anti-icing operations for aircraft waiting on the ground for takeoff are primarily carried out using liquid de-icing and anti-icing technologies (spraying de-icing fluid), mechanical methods (pneumatic belt de-icing technology, electrical pulse de-icing), and electrothermal or pneumatic de-icing and anti-icing technologies. Typically, in the practical application of de-icing and anti-icing technologies, pre-takeoff icing inspection is an essential step, and according to de-icing and anti-icing standards, this should be assessed manually by observation and touch. However, since aircraft are far from the tarmac before takeoff, external manual inspection is difficult, and naked-eye observation of the aircraft's interior is often affected by external lighting conditions. Especially at night with insufficient light, the assessment of the anti-icing effect on the aircraft surface is often influenced by subjective factors, posing a significant hidden danger to safe flight. Therefore, in order to ensure flight safety, there is an urgent need to develop a convenient, accurate and intuitive method for detecting secondary icing of aircraft after de-icing operations are completed, for the visual judgment of fuselage icing. This is not only an important requirement to ensure safe flight, but also a necessity to promote and adapt to the development of smart civil aviation.
[0004] Currently, there are no reports worldwide on its application in visual detection of icing. Research is needed on functional materials exhibiting aggregation-induced emission (AIE) luminescence behavior, and based on this, to develop related anti-icing fluid systems. This involves realizing the transformation of AIE molecules from a freely dispersed low-energy state (extinction or weak light state) to a densely packed high-energy state (electron non-radiative transition) during the phase transition of anti-icing failure. Macroscopically, this would demonstrate photoluminescence behavior in the AIE-containing anti-icing fluid under icing conditions after anti-icing failure, thus enabling visual detection of aircraft secondary icing using optical signals. This has significant theoretical and practical value in ensuring flight safety. Some studies have attempted to use phosphorescent materials (such as boron-based carbon quantum dots), but these methods suffer from the following drawbacks: electrolyte properties lead to a decrease in anti-icing fluid viscosity, significantly reducing anti-icing time; the luminescence duration is short (<2 seconds), leaving no time for visual detection; continuous ultraviolet excitation is required, making it unsuitable for rapid on-site detection; and compatibility with anti-icing fluid components is poor. This invention utilizes AIE organic photoluminescent materials for the research and development of de-icing and anti-icing fluid systems and the practical application of icing visualization detection, thus improving and addressing the shortcomings of existing de-icing and anti-icing products in practical applications. In particular, it enables the establishment of an anti-icing fluid system with visualized early warning of anti-icing effects based on AIE molecules with independent intellectual property rights, providing a strong theoretical research foundation and applied technical support for the development of smart civil aviation. Summary of the Invention
[0005] In view of this, the present invention provides a method for preparing an aircraft anti-icing fluid containing a gram-level water-soluble aggregation-induced light-emitting polymer. Specifically, the technical solution is as follows:
[0006] A method for preparing a gram-scale water-soluble aggregation-induced emission polymer includes the following steps:
[0007] 1) Add bisacrylamide and a difunctional water-soluble basic amino acid to a mixed solution of ethanol and water at a molar ratio of 1.3 / 1, vortex mix to form a homogeneous reaction solution, bubble with nitrogen or argon to remove oxygen for 15-30 minutes, and then add triethylamine.
[0008] 2) The Michael addition reaction is carried out in a Schlenk polymerization tube, reaction flask or reaction vessel at a temperature of 50℃-90℃ for a time of 2-24 h.
[0009] 3) After the reaction is complete, the reaction solution is initially concentrated using a rotary evaporator and then precipitated in a large amount of ethanol to obtain a pale yellow or orange-red precipitate.
[0010] 4) After collection and drying, a polymer material emitting aggregation-induced white fluorescence is obtained.
[0011] 5) Add the polymer material from step 4) to the type IV anti-icing fluid at a rate of 0.2 wt%.
[0012] Furthermore, the bifunctional water-soluble basic amino acid mentioned in step 1) includes one or more of lysine, arginine, ornithine, and theanine.
[0013] Furthermore, the bifunctional water-soluble basic amino acid mentioned in step 1) is lysine.
[0014] Furthermore, the bisacrylamide mentioned in step 1) is N,N'-methylenebisacrylamide.
[0015] Furthermore, in step 1), the mass ratio of ethanol to water in the mixed solution is no higher than 9 / 1.
[0016] Furthermore, the reaction temperature in step 2) is 70°C, and the reaction time is 5 hours.
[0017] 7. A gram-scale water-soluble aggregation-induced emission polymer prepared by the preparation method according to any one of claims 1-6.
[0018] The beneficial effects of this invention are as follows: According to existing literature, the synthetic pathways for AIE molecules are relatively complex, requiring multiple steps of reaction and purification, metal catalysis, and group protection to obtain fluorescent products with high luminescence efficiency. In particular, the synthesis of tetraphenylethylene-based AIE molecules has not yet achieved a simplified and efficient synthetic route to obtain kilogram-level products. The gram-level water-soluble aggregation-induced emission polymer of this invention can be effectively dissolved in aircraft de-icing fluids (alcohol-water system), without significantly affecting the anti-icing time of the de-icing fluid. The synthesized AIE molecules do not require water-soluble modification or alteration, and can be integrated with existing commercial aircraft de-icing fluid systems. Only visual inspection assisted by a UV light source is needed to quickly, accurately, and efficiently detect secondary icing on critical aircraft surfaces under low-temperature conditions, giving in-use aircraft de-icing fluid products additional anti-icing detection capabilities, achieving compatibility between anti-icing performance and visual inspection. Attached Figure Description
[0019] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided:
[0020] Figure 1 The results are for molecular structure characterization.
[0021] Figure 2 The results show the optical properties and photoluminescence characterization of AIE polymer molecules.
[0022] Figure 3The luminescence behavior of the synthesized product in Example 1 under visible light and blue light (λ=365 nm) irradiation conditions is shown.
[0023] Figure 4 A visual comparison chart of test results simulating secondary icing after an aircraft is sprayed with anti-icing fluid. Detailed Implementation
[0024] The preferred embodiments of the present invention will now be described in detail.
[0025] Example 1
[0026] (1) Synthesis
[0027] Raw material: N,N'-methylenebisacrylamide / lysine, with a molar ratio of 1.3 / 1;
[0028] Reaction: Add to a mixed solution of ethanol and water, heat to 70°C and vortex mix to form a homogeneous reaction solution. After purging oxygen with nitrogen or argon for 15-30 minutes, add a small amount of triethylamine (catalytic grade). The reaction time is 5 hours.
[0029] Post-processing: After the reaction was completed, the reaction solution was initially concentrated using a rotary evaporator, precipitated in a large amount of ethanol, collected, and dried.
[0030] (2) Preparation of anti-icing fluid:
[0031] The product synthesized in step (1) was added to type IV anti-icing fluid at a rate of 0.2 wt%.
[0032] Comparative Example 1
[0033] (1) Synthesis
[0034] Raw material: N,N'-methylenebisacrylamide / lysine, with a molar ratio of 1.8 / 1;
[0035] Reaction: Add to a mixed solution of ethanol and water, heat to 70°C and vortex mix to form a homogeneous reaction solution. After purging oxygen with nitrogen or argon for 15-30 minutes, add a small amount of triethylamine (catalytic grade). The reaction time is 5 hours.
[0036] Post-processing: After the reaction was completed, the reaction solution was initially concentrated using a rotary evaporator, precipitated in a large amount of ethanol, collected, and dried.
[0037] (2) Preparation of anti-icing fluid:
[0038] The product synthesized in step (1) was added to type IV anti-icing fluid at a rate of 0.2 wt%.
[0039] Comparative Example 2
[0040] (1) Synthesis
[0041] Raw material: N,N'-methylenebisacrylamide / lysine, with a molar ratio of 1.3 / 1;
[0042] Reaction: Add to a mixed solution of ethanol and water, heat to 70°C and vortex mix to form a homogeneous reaction solution. After purging oxygen with nitrogen or argon for 15-30 minutes, add a small amount of triethylamine (catalytic grade). The reaction time is 5 hours.
[0043] Post-processing: After the reaction was completed, the reaction solution was initially concentrated using a rotary evaporator, precipitated in a large amount of ethanol, collected, and dried.
[0044] (2) Preparation of anti-icing fluid
[0045] The synthesized product was added to type IV anti-icing fluid at a rate of 0.4 wt%.
[0046] Comparative Example 3
[0047] (1) Synthesis
[0048] Raw material: N,N'-methylenebisacrylamide / lysine, with a molar ratio of 1.3 / 1;
[0049] Reaction: Add to a mixed solution of ethanol and water, heat to 40°C and vortex to form a homogeneous reaction solution. After purging oxygen with nitrogen or argon for 15-30 minutes, add a small amount of triethylamine (catalytic grade). The reaction time is 5 hours.
[0050] Post-processing: After the reaction was completed, the reaction solution was initially concentrated using a rotary evaporator, precipitated in a large amount of ethanol, collected, and dried.
[0051] (2) Preparation of anti-icing fluid
[0052] The synthesized product was added to type IV anti-icing fluid at a concentration of 0.2 wt%. No polymer was successfully synthesized.
[0053] Test Example 1
[0054] 1. Characterization of the molecular structure of the synthesized AIE polymer
[0055] The synthesis method in step (1) of Example 1 and Comparative Example 1 is the same, and both yield liquid products. However, in Comparative Example 1, the proportion of N,N'-methylenebisacrylamide was increased, resulting in a gel-like product that was difficult to dissolve in type IV de-icing fluid. This is because N,N'-methylenebisacrylamide contains double bonds, and excess N,N'-methylenebisacrylamide easily forms a cross-linked structure, resulting in a product with an excessively large molecular weight and a gel-like consistency. The raw material ratio of Comparative Example 3 was the same as in the examples, but the reaction temperature was lowered to 40°C. No polymer was generated within the same reaction time, indicating that this temperature did not reach the threshold for molecular reaction kinetics. The molecular structure of the product synthesized in step (1) of Example 1 was characterized by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). Figure 1 The results are for molecular structure characterization.
[0056] Figure 1 (A) is the 1H NMR spectrum. The characteristic signal of CH hydrogen on the methylene group is at 1.0-2.0 ppm, and the characteristic signal of CH2 on the methylene group is at 2.0-3.0 ppm. The signal peaks are blunt peaks, characteristic of the polymer's 1H NMR spectrum. HBP is known to be a hyperbranched polyamine, L-lysine is lysine, and MBA is N,N-dimethylformamide. Figure 1 In (B), a value at 3298 cm⁻¹ can be observed in the HBP infrared spectrum. -1 The peak value is the -NH2 stretching vibration peak at 2918 cm⁻¹. -1 The peak at 1724 cm⁻¹ represents the CH stretching vibration. -1 The peak at 1654 cm⁻¹ represents the carbonyl stretching vibration. -1 The peak at 1523 cm⁻¹ represents the -NC stretching vibration in the amide I band. -1 The peak is the -NH stretching vibration peak in the amide II band. Since the HBP infrared spectrum simultaneously shows the carbonyl group of MBA and the amide characteristic peak of lysine, and changes from NH2 (amine) to amide characteristic peak, it is determined that a hyperbranched polyamine has been synthesized. Figure 1 (C) The presence of three step peaks in the thermogravimetric analysis spectrum indicates that it is a non-homogeneous polymer with a multi-segment structure after polymerization of different monomers. Figure 1 Analysis of the results obtained by the three characterization methods shows that Example 1 indeed synthesized the designed AIE polymer molecule.
[0057] Test Example 2
[0058] 1. Luminescence behavior test
[0059] The optical properties of the product synthesized in Example 1 were characterized. Figure 2 The results show the characterization of the optical properties and photoluminescence of AIE polymer molecules. Figure 2As can be seen from the data, the UV-vis spectrum (A) shows that the synthesized product has three characteristic absorption peaks with absorption wavelengths of 286, 437, and 543 nm. This preliminarily confirms that the synthesized product conforms to the description of AIE molecular aggregation-induced emission. The mechanism by which it achieves photoluminescence is that the molecular structure contains red, blue, and green primary color absorption groups, which emit white fluorescence in the form of composite light under blue light excitation. The excitation-emission fluorescence spectrum (B) shows that under blue light source excitation (λ=365 nm) emission conditions, the synthesized product of Example 1 exhibits triple excitation characteristics, with optimal emission wavelengths located at 392, 472, and 576 nm, all in the visible light region, displaying an overall white spectrum. The luminescence mechanism indicates that this is beneficial for applications that visualize and detect icing effects.
[0060] 2. Specific light source test
[0061] Test method: The synthesized product of Example 1 was irradiated with visible light and a specific light source (λ=365 nm).
[0062] Test results: Figure 3 The image shows the luminescence behavior of the product synthesized in Example 1 under visible light and blue light (λ=365 nm) irradiation conditions. It can be seen that the product synthesized in Example 1 does not emit light under visible light irradiation, but only emits white light under a specific light source (λ=365 nm), further verifying the synthesis of the AIE polymer and its photoluminescence effect only under a specific light source.
[0063] 3. Visual test of secondary icing
[0064] Test method: Visual detection of secondary icing after the anti-icing fluid is sprayed on an aircraft. The Type IV anti-icing fluids obtained in Example 1 and Comparative Examples 1-3 were rapidly cooled to complete freezing and then irradiated with a specific light source (λ=365 nm). The comparative sample of the Type IV anti-icing fluid in Example 1 before and after freezing was irradiated with a specific light source (λ=365 nm).
[0065] Test results: Figure 4 This is a comparison chart showing the visual detection results of secondary icing after anti-icing fluid is sprayed on an aircraft. (B) shows the luminescence behavior of the Type IV anti-icing fluid from Example 1 before and after icing under a specific light source (λ=365 nm). It can be seen that the Type IV anti-icing fluid from Example 1 does not emit light under the specific light source when undisturbed at room temperature, but emits significant light when iced. (A) shows the luminescence behavior of Comparative Examples 1-3 and the Type IV anti-icing fluid from Example 1 after icing under a specific light source (λ=365 nm). Visually, Example 1 shows the highest luminescence intensity, Comparative Example 2 shows weak luminescence, and Comparative Examples 1 and 3 show no luminescence at all.
[0066] The actual luminescence results further confirmed the previous judgment. The gel in Comparative Example 1 was insoluble, and Comparative Example 3 did not synthesize the AIE polymer. Therefore, the corresponding Type IV anti-icing fluid did not contain luminescent material and could not achieve the application effect of visually detecting secondary icing. Example 1 and Comparative Example 2 successfully synthesized the AIE polymer, but the concentration added to the Type IV de-icing fluid in Example 1 was better than that in Comparative Example 2, and the strongest luminescence effect could be observed.
[0067] 4. Anti-icing fluid performance test
[0068] According to the SAE AMS 1428 SAE Type II, III and IV non-Newtonian fluid aircraft de-icing / anti-icing fluid standard requirements, the performance of the Type IV anti-icing fluids prepared in step (2) of Example 1 and Comparative Examples 1-3 was tested, and the specific results are shown in Table 1. In the viscosity test data, the viscosities of Example 1 and Comparative Example 3 are relatively close, while the viscosities of Comparative Examples 1 and Comparative Example 2 are significantly reduced. This is because the gel synthesized in Comparative Example 1 is slightly soluble in Type IV anti-icing fluid, and its addition has a certain impact on its viscosity. However, the AIE polymer is soluble in Type IV anti-icing fluid, and the addition concentration of Comparative Example 2 significantly reduces the viscosity of Type IV anti-icing fluid, which has a significant impact on its performance. The addition ratio of Example 1 has little effect on the final viscosity of Type IV anti-icing fluid, while Comparative Example 3 did not successfully synthesize polymer, so its effect on the final viscosity is negligible.
[0069] In the test data of water spray anti-icing time, Comparative Example 2 had the shortest anti-icing time because the anti-icing fluid needs a certain viscosity to adhere to the aircraft fuselage to achieve the anti-icing effect. The low viscosity also led to a significant decrease in the water spray anti-icing time. Example 1 slightly affected the viscosity of the Type IV anti-icing fluid, and the water spray anti-icing time also decreased slightly. Comparative Example 3 did not successfully synthesize a polymer, so the addition of Type IV anti-icing fluid had almost no effect on its viscosity. The gel synthesized in Comparative Example 1 was slightly soluble in Type IV anti-icing fluid, which affected its viscosity and caused a certain decrease.
[0070] Table 1. Test data of anti-icing fluid performance in Example 1 and Comparative Examples 1-3
[0071] Test Items Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Viscosity (20℃) 25920 cp 21470 cp 14950 cp 26480 cp Water spray anti-icing time 100min 65min 20min 110min
[0072] In summary, Comparative Examples 1 and 3 showed no luminescence under illumination, indicating that the AIE polymer product was not successfully synthesized and the goal of visual detection of secondary icing could not be achieved. The concentration in Comparative Example 2 was too high, leading to a significant decrease in the viscosity of the Type IV anti-icing fluid, resulting in a significant reduction in anti-icing time. Furthermore, the luminescence brightness under illumination was far inferior to that of Example 1, therefore it was not the optimal addition ratio.
[0073] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.
Claims
1. An aircraft comprising a gram-scale water-soluble aggregation-induced emission polymer The preparation method of the anti-icing liquid is characterized in that, The preparation method comprises the following steps: 1) adding double acrylamide and double functionality water-soluble basic amino acid in a molar ratio of 1.3 / 1 into a mixed solution of ethanol and water, vortex mixing to form a homogeneous reaction solution, bubbling with nitrogen or argon to remove oxygen for 15-30 minutes, and then adding triethylamine; 2) performing a Michael addition reaction in a Schlenk polymerization tube, a reaction bottle or a reaction kettle, the reaction temperature is 50-90°C, and the reaction time is 2-24 hours; 3) after the reaction is completed, the reaction liquid is preliminarily concentrated by a rotary evaporator, and then precipitated in a large amount of ethanol to obtain a light yellow or orange red precipitate; 4) after collection and drying, a polymer material emitting an aggregation-induced white light fluorescence performance is obtained; 5) the polymer material in step 4) is added into the type IV anti-icing liquid, and the addition amount is 0.2wt%.
2. The method for preparing a gram-level water-soluble aggregation-induced emission polymer-containing aircraft deicing fluid according to claim 1, characterized in that, The double functionality water-soluble basic amino acid in step 1) includes one or more of lysine, arginine, ornithine and theanine.
3. The method for preparing a gram-scale water-soluble aggregation-induced emission polymer-containing aircraft deicing fluid according to claim 1, characterized in that, The double functionality water-soluble basic amino acid in step 1) is lysine.
4. The method for preparing a gram-scale water-soluble aggregation-induced emission polymer-containing aircraft deicing fluid according to claim 1, characterized in that, The double acrylamide in step 1) is N, N'-methylene double acrylamide.
5. The method for preparing a gram-scale water-soluble aggregation-induced emission polymer-containing aircraft deicing fluid according to claim 1, characterized in that, The mixed solution of ethanol and water in step 1) has a mass ratio of ethanol to water not higher than 9 / 1.
6. The method for preparing a gram-scale water-soluble aggregation-induced emission polymer-containing aircraft deicing fluid according to claim 1, characterized in that, The reaction temperature in step 2) is 70°C, and the reaction time is 5 hours.
7. A gram-level water-soluble aggregation-induced light-emitting polymer anti-icing liquid prepared by the preparation method according to any one of claims 1-6.