A corrosion-resistant treatment method for infrared regulating film material

Abstract

The present application belongs to the field of infrared regulation material corrosion and protection, and specifically relates to an anti-corrosion treatment method for infrared regulation film material. The present application performs surface cleaning and oxygen plasma treatment on the film material to be protected, and then coats 10-40 mg / mL polystyrene toluene solution on the surface of the material, and heats and dries to form a film to prepare a polystyrene protective layer with a thickness of less than or equal to 200 nm. The present application prepares an ultrathin polystyrene protective layer by spin coating, solves the problem of the influence of traditional anti-corrosion strategies on the infrared performance of the film material, and through experimental verification, the influence of the protective layer with a thickness of less than or equal to 200 nm on the original infrared spectral characteristics of the film material can be ignored, and the corrosion resistance of the material can be significantly improved, and the material can be stably served at a high temperature of 250 DEG C. The process is controllable, the raw material cost is low, and is suitable for the structure and performance characteristics of the infrared regulation film material, retains the material design freedom, and expands the actual application scenarios of the material.

Description

Technical Field

[0001] This invention relates to the field of corrosion and protection technology for infrared modulated materials, specifically a corrosion-resistant treatment method for infrared modulated thin film materials. It is applicable to the corrosion-resistant modification of infrared modulated thin film materials prepared by methods such as electron beam evaporation, magnetron sputtering, and laser pulse deposition. It can improve corrosion resistance without significantly affecting the infrared optical performance, thus expanding the practical application scenarios of the materials in fields such as construction, industry, military, and energy. Background Technology

[0002] Infrared modulation technology has key applications in energy utilization, thermal management, national defense, and thermophotovoltaic (TPV) systems. Infrared-modulated thin film materials, with their extremely high degree of structural freedom, can achieve specific infrared properties as needed, and their performance is superior to that of coating materials. However, current research on improving the corrosion resistance of these thin film materials has many shortcomings:

[0003] 1. Existing corrosion resistance strategies are mostly aimed at coating materials, such as filler surface modification and the addition of corrosion inhibitors, which cannot be applied due to the differences in structure and preparation process between thin films and coatings;

[0004] 2. Existing research on thin film corrosion resistance focuses only on the selection of materials themselves (such as the precious metal Au), which limits the degree of design freedom and the upper limit of performance, and lacks economic applicability;

[0005] 3. The external inorganic infrared transparent protective layer (such as MgF2, ZnS) is nanometer-thick, which has limited protective effect. Moreover, this type of material is sensitive to humid environments and has poor anti-corrosion effect in humid environments. At the same time, the unavoidable structural defects in the film preparation process also restrict the improvement of corrosion resistance.

[0006] 4. The thickness of traditional organic polymer protective layers is tens to hundreds of micrometers, and their characteristic absorption peaks in the infrared band severely affect the infrared performance of thin film materials. Summary of the Invention

[0007] To address the aforementioned problems and shortcomings, and to resolve the contradiction between optical and corrosive properties in traditional corrosion strategies for existing infrared-controlled thin film materials, this invention provides a corrosion-resistant treatment method for infrared-controlled thin film materials. The core objective is to significantly improve the corrosion resistance of the thin film material without significantly affecting its original infrared spectral characteristics, thereby enhancing its performance in practical applications, while also considering the operability and economic applicability of the process.

[0008] A corrosion-resistant treatment method for infrared-controlled thin film materials includes three core steps: surface cleaning, oxygen plasma treatment, and spin-coating with a polystyrene solution to form a film, as detailed below:

[0009] Step 1, Surface Cleaning: Clean the surface of the infrared control film material to be protected to remove surface oil and adsorbed impurities. Ultrasonic cleaning is preferred.

[0010] Step 2, Oxygen plasma treatment: The cleaned film material surface is treated with oxygen plasma to increase the surface energy of the material, reduce the wetting angle, improve surface wettability, and ensure uniform distribution of the protective layer in subsequent coatings (such as spin coating).

[0011] Step 3, preparation of polystyrene protective layer: Coat the surface of the film material obtained in step 2 with a polystyrene toluene solution with a concentration of 10-40 mg / mL, and heat and dry to form a film. The thickness of the prepared polystyrene film (protective layer) is ≤200 nm.

[0012] Furthermore, the coating process employs spin coating technology, specifically as follows: ① The infrared-controlled thin film material to be protected is fixed on a spin coater; ② The spin coating speed, acceleration, and spin coating time are set according to the target film thickness; ③ 2 mL of polystyrene-toluene solution is dropped onto the material surface; ④ The spin coater is started to complete the spin coating; After spin coating, the sample is placed on a heating platform at 120°C and heated for 10 minutes to allow the remaining solvent to completely evaporate.

[0013] Furthermore, the preferred preparation process parameters for the 100nm thick polystyrene protective layer are as follows: using a 10mg / mL polystyrene-toluene solution, and spin coating parameters of 2000rpm rotation speed, 1000rpm / s acceleration, and 60s spin coating time.

[0014] Furthermore, the preferred preparation process parameters for the 200nm thick polystyrene protective layer are as follows: using a 20mg / mL polystyrene-toluene solution, and spin coating parameters of 2000rpm rotation speed, 1000rpm / s acceleration, and 60s spin coating time.

[0015] Furthermore, the above-mentioned corrosion-resistant treatment method for infrared-controlled thin film materials allows the polystyrene protective layer after treatment to operate stably at a high temperature of 250°C. Moreover, after neutral salt spray tests for 48h, 96h, and 144h, it can effectively protect the original infrared performance of the infrared-controlled thin film material.

[0016] Compared with the prior art, the present invention has the following significant advantages:

[0017] 1. No significant impact on optical performance: When the thickness of the prepared polystyrene protective layer is ≤200nm, the infrared emissivity of the film material is basically consistent with that of the original material. The infrared characteristic absorption peak of polystyrene in the 3-4μm range is weak, and the impact on the original infrared spectral characteristics is negligible. This avoids the problem of infrared performance degradation caused by excessive thickness of traditional organic protective layers.

[0018] 2. Significantly improved corrosion resistance: Verified by neutral salt spray tests for 48h, 96h, and 144h, the infrared emissivity data error of the film material with a spin-coated 200nm polystyrene protective layer is much smaller than that of the uncoated sample. The protective layer can effectively isolate the corrosive medium and protect the original infrared performance of the film material from corrosion damage.

[0019] 3. Excellent high temperature resistance: After the 200nm polystyrene protective layer is heated at 250℃ for 30 minutes, the infrared properties of the film material remain basically unchanged, and the infrared characteristic peaks of the protective layer still exist, proving that it can be used in special high temperature environments.

[0020] 4. Controllable and economical process: By precisely controlling parameters such as solution concentration, rotation speed, and acceleration through spin coating technology, controllable preparation of micro-nano-scale protective layers can be achieved; polystyrene raw materials are inexpensive, and the spin coating process is simple to operate, making it suitable for large-scale applications.

[0021] 5. Strong adaptability: This method is designed specifically for the structural and performance characteristics of infrared-controlled thin film materials, solving the problem of incompatibility of anti-corrosion strategies for coating materials. Furthermore, it does not require the selection of precious metal substrates, thus preserving the freedom of material design and the upper limit of performance.

[0022] 6. Polystyrene (PS) has high transparency, low cost, excellent electrical / thermal insulation, good chemical stability, low water absorption, weather resistance, and can withstand alkalis, salts and aqueous solutions, making it an excellent candidate for anti-corrosion materials; spin coating technology can prepare micro-nano-scale films by controlling process parameters, providing technical support for the preparation of ultrathin organic protective layers.

[0023] In summary, this invention, by controlling polystyrene (PS) to a specific thickness in a way that defies industry norms, allows it to be used as an infrared transparent protective layer in infrared modulated film materials, thereby significantly improving the corrosion resistance of the material without affecting the spectral characteristics of the original infrared modulated film materials. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the expected protection effect.

[0025] Figure 2 The infrared spectrum of polystyrene (PS) with a thickness of 100 μm;

[0026] Figure 3 The infrared transmittance test results of spin-coating polystyrene solution with a concentration of 10 mg / mL onto double-sided polished silicon wafers using different spin-coating process parameters;

[0027] Figure 4 for Figure 3 A magnified view of a portion of the image;

[0028] Figure 5The infrared transmittance test results of spin-coating polystyrene solution with a concentration of 20 mg / mL onto double-sided polished silicon wafers using different spin-coating process parameters;

[0029] Figure 6 for Figure 5 A magnified view of a portion of the image;

[0030] Figure 7 The infrared transmittance test results of spin-coating polystyrene solution with a concentration of 40 mg / mL onto double-sided polished silicon wafers using different spin-coating process parameters;

[0031] Figure 8 for Figure 7 A magnified view of a portion of the image;

[0032] Figure 9 The thickness of the spin-coated polystyrene was measured by AFM after spin-coating a 10 mg / mL polystyrene solution onto a double-sided polished silicon wafer using spin-coating parameters of 2000 rpm spin speed, 1000 rpm / s acceleration, and 60 s time. The polystyrene thickness was 93 nm.

[0033] Figure 10 The thickness of the spin-coated polystyrene was measured by AFM after spin-coating a 20 mg / mL polystyrene solution onto a double-sided polished silicon wafer using spin-coating parameters of 2000 rpm spin speed, 1000 rpm / s acceleration, and 60 s time. The polystyrene thickness was 192 nm.

[0034] Figure 11 The thickness of the spin-coated polystyrene was measured by AFM after spin-coating a 40 mg / mL polystyrene solution onto a double-sided polished silicon wafer using spin-coating process parameters of 4000 rpm, 2000 rpm / s, and 60 s. The polystyrene thickness was 379 nm.

[0035] Figure 12 The infrared emissivity of polystyrene solutions of different thicknesses loaded onto the surface of infrared modulated thin film materials at 3-5 μm and 8-14 μm was measured under three spin-coating processes: 10 mg / mL polystyrene solution (spin-coating speed 2000 rpm, acceleration 1000 rpm / s, time 60 s), 20 mg / mL polystyrene solution (spin-coating speed 2000 rpm, acceleration 1000 rpm / s, time 60 s), and 40 mg / mL polystyrene solution (spin-coating speed 4000 rpm, acceleration 2000 rpm / s, time 60 s).

[0036] Figure 13 for Figure 12 A magnified view of a portion of the image;

[0037] Figure 14-15 Infrared emissivity error band diagrams of spin-coated and unspin-coated polystyrene infrared modulated thin film materials after 48 hours of neutral salt spray test;

[0038] Figure 16-17 Infrared emissivity error band diagrams of spin-coated and unspin-coated polystyrene infrared modulated thin film materials after 96 hours of neutral salt spray test;

[0039] Figure 18-19 Infrared emissivity error band diagrams of spin-coated and unspin-coated polystyrene infrared modulated thin film materials after 144 hours of neutral salt spray test;

[0040] Figure 20 A comparison of the changes in infrared emissivity of an infrared-controlled thin film material with a 200 nm polystyrene protective layer prepared by spin coating with a polystyrene solution of 20 mg / mL and spin coating parameters of 2000 rpm spin speed, 1000 rpm / s acceleration and 60 s time.

[0041] Figure 21 for Figure 20 A magnified view of a portion of the image. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0043] Figure 1 This diagram illustrates the expected protective effect. The polystyrene layer can prevent corrosive media from contacting the protected material, thereby improving the material's corrosion resistance.

[0044] Experimental preparation:

[0045] 1. Prepare polystyrene solutions: Using toluene as a solvent, prepare polystyrene toluene solutions with concentrations of 10 mg / mL, 20 mg / mL, and 40 mg / mL, respectively, and stir until completely dissolved.

[0046] 2. Sample pretreatment: Select the infrared-controlled thin film material to be protected and the double-polished Si wafer (for process parameter verification). Use ultrasonic cleaning to remove surface oil and impurities. After drying, perform oxygen plasma treatment to improve surface wettability.

[0047] Preparation of polystyrene thin films by spin coating:

[0048] Pretreated double-sided polished Si wafers and infrared-controlled thin film materials were fixed on a spin coater, and 2 mL of polystyrene toluene solution of corresponding concentration was added. Spin coating was performed according to different spin coating parameters (rotation speed 1000-4000 rpm, acceleration 1000-2000 rpm / s, spin coating time 60 s). After spin coating, all samples were placed on a 120℃ heating table and heated for 10 min to evaporate the remaining solvent, thus obtaining polystyrene film samples.

[0049] For the addition of a 10 mg / mL polystyrene solution, the spin-coating test conditions were as follows: 4000 rpm, acceleration 2000 rpm / s, duration 60 s; 4000 rpm, acceleration 1000 rpm / s, duration 60 s; 2000 rpm, acceleration 2000 rpm / s, duration 60 s; 2000 rpm, acceleration 1000 rpm / s, duration 60 s; 1000 rpm, acceleration 1000 rpm / s, duration 60 s. A total of five groups of samples were tested, and the infrared transmittance test results for 3-14 μm are as follows. Figure 3 As shown, through Figure 3 Enlarged image within the black frame Figure 4 As shown, the infrared transmittance of samples under different test conditions was compared. For polystyrene, the peak intensity of the infrared characteristic absorption peaks at 3.3 μm and 3.4 μm (relative to the baseline) decreased with the decrease of polystyrene thickness, and the overall value was ≤1.9%.

[0050] For the addition of a 20 mg / mL polystyrene solution, the spin-coating test conditions were as follows: spin speed 4000 rpm, acceleration 2000 rpm / s, duration 60 s; spin speed 4000 rpm, acceleration 1000 rpm / s, duration 60 s; spin speed 2000 rpm, acceleration 2000 rpm / s, duration 60 s; spin speed 2000 rpm, acceleration 1000 rpm / s, duration 60 s; spin speed 1000 rpm, acceleration 1000 rpm / s, duration 60 s. A total of five groups of samples were tested, and the infrared transmittance test results are as follows: Figure 5 As shown, through Figure 5 Enlarged image of the area within the black frame Figure 6 As shown, the infrared transmittance of samples under different test conditions was compared. For polystyrene, the peak intensity of the infrared characteristic absorption peaks at 3.3 μm and 3.4 μm (relative to the baseline) decreased with the decrease of polystyrene thickness, and the overall value was ≤2.1%.

[0051] For the addition of a 40 mg / mL polystyrene solution, the spin-coating test conditions were as follows: spin speed 4000 rpm, acceleration 2000 rpm / s, duration 60 s; spin speed 4000 rpm, acceleration 1000 rpm / s, duration 60 s; spin speed 2000 rpm, acceleration 2000 rpm / s, duration 60 s; spin speed 2000 rpm, acceleration 1000 rpm / s, duration 60 s; spin speed 1000 rpm, acceleration 1000 rpm / s, duration 60 s. A total of five groups of samples were tested, and the infrared transmittance test results are as follows: Figure 7 As shown, through Figure 7 Enlarged image of the area within the black frame Figure 8 As shown, the infrared transmittance of samples under different test conditions was compared. For polystyrene, the peak intensity of the infrared characteristic absorption peaks at 3.3 μm and 3.4 μm (relative to the baseline) decreased with the decrease of polystyrene thickness, and the overall value was ≤6.1%.

[0052] Process parameter verification test

[0053] 1. Infrared transmittance test: Infrared transmittance tests were conducted on double-coated polished Si wafer samples with different concentrations and spin-coating processes at 3-14 μm. The results showed that the peak intensity of the characteristic infrared absorption peaks of polystyrene at 3.3 μm and 3.4 μm decreased with decreasing film thickness; the peak intensity of the sample prepared with 10 mg / mL solution was ≤1.9%, the peak intensity of the sample prepared with 20 mg / mL solution was ≤2.1%, and the peak intensity of the sample prepared with 40 mg / mL solution was ≤6.1%.

[0054] 2. Film thickness test: Use a blade to draw steps on the surface of the spin-coated double-polished Si wafer, and use AFM to test the film thickness to screen out the process parameters that can prepare protective layers of about 100nm, 200nm, and 400nm (i.e. the preferred parameters described in the invention).

[0055] Infrared performance impact verification

[0056] For infrared modulated thin film materials with spin-coated 100nm, 200nm, and 400nm polystyrene protective layers, the infrared emissivity (E=1-reflectivity R, transmittance T is considered 0) was measured using the integrating sphere reflectance test method of an infrared spectrometer. The results show:

[0057] 1. The 400nm protective layer causes a rightward shift of about 1μm in the infrared spectrum of the thin film material, and a distinct polystyrene characteristic absorption peak appears at 3-4μm, affecting the infrared performance;

[0058] 2. The emissivity of the 100nm and 200nm protective film materials is basically the same as that of the original material, and the characteristic absorption peak of 3-4μm is weak, so its influence on infrared performance is negligible.

[0059] Corrosion resistance verification

[0060] A 200nm polystyrene protective film material was selected as the experimental group, and the uncoated sample was selected as the control group. Neutral salt spray test was conducted. After corrosion for 48h, 96h, and 144h, the infrared emissivity was tested using the five-point sampling method. The results showed that the emissivity data error of the experimental group was much smaller than that of the control group. The protective layer can effectively block the corrosive medium, significantly improve the corrosion resistance of the film material, and protect the original infrared performance.

[0061] To verify the protective effect of the protective layer, a 200nm thick protective layer was spin-coated onto the surface of the infrared-controlled thin film material. The infrared-controlled thin film materials before and after spin-coating were subjected to neutral salt spray tests, and were removed after 48h, 96h, and 144h respectively. Samples at different corrosion times were tested multiple times using a five-point sampling method to compare the changes in infrared emissivity before and after corrosion. Figure 14-19 The error band diagram shows that the anti-corrosion effect is significant after adding the protective layer. The emissivity data error of the spin-coated polystyrene at different corrosion times is much smaller than that of the infrared modulated film material before spin-coating polystyrene, which proves that polystyrene protects the original infrared performance of the infrared modulated film material.

[0062] High temperature resistance performance verification

[0063] To further verify the durability of the polystyrene protective layer under special conditions, an infrared-modulated thin film material with a spin-coated 200nm thick protective layer was subjected to a heating and holding test using a heating stage. The test procedure was as follows: the heating stage was preheated to the specified temperature; the infrared-modulated thin film material was placed on the surface of the heating stage and heated; after the sample temperature stabilized, it was held at that temperature for 30 minutes; the power to the heating stage was turned off, and the sample was allowed to cool naturally to room temperature. Figure 20 As shown, by comparing the emissivity data of the infrared-controlled thin film material before and after heating, it can be seen that the infrared performance of the infrared-controlled thin film material remains basically unchanged before and after heating and heat preservation. Meanwhile, from... Figure 21 The characteristic peaks of polystyrene around 3.3μm and 3.4μm are still present, proving the feasibility of using the protective layer at 250 degrees Celsius.

Claims

1. A method for corrosion-resistant treatment of infrared-controlled thin film materials, characterized in that, Includes the following steps: Step 1: Clean the surface of the infrared modulation film material to be protected to remove surface oil and adsorbed impurities; Step 2: Perform oxygen plasma treatment on the cleaned film material surface to increase the surface energy and improve surface wettability; Step 3: Coat the surface of the thin film material obtained in Step 2 with a polystyrene toluene solution with a concentration of 10-40 mg / mL, and heat and dry it to form a film. The thickness of the prepared polystyrene film is ≤200 nm.

2. The corrosion-resistant treatment method for the infrared-controlled thin film material as described in claim 1, characterized in that: In step 1, ultrasonic cleaning is used to clean the surface of the thin film material.

3. The corrosion-resistant treatment method for the infrared-controlled thin film material as described in claim 1, characterized in that: The coating process in step 3 is spin coating. The specific operation is as follows: ① Fix the infrared-controlled film material to be protected on the spin coater; ② Set the spin coating speed, acceleration and spin coating time; ③ Add 2 mL of polystyrene toluene solution; ④ Start the spin coater to complete the spin coating.

4. The corrosion-resistant treatment method for the infrared-controlled thin film material as described in claim 1, characterized in that: The process parameters for preparing the 100nm polystyrene protective layer are as follows: using a 10mg / mL polystyrene-toluene solution, a spin coating speed of 2000rpm, an acceleration of 1000rpm / s, and a spin coating time of 60s.

5. The corrosion-resistant treatment method for the infrared-controlled thin film material as described in claim 1, characterized in that: The process parameters for preparing the 200nm polystyrene protective layer are as follows: using a 20mg / mL polystyrene-toluene solution, a spin coating speed of 2000rpm, an acceleration of 1000rpm / s, and a spin coating time of 60s.

6. The corrosion-resistant treatment method for the infrared-controlled thin film material as described in claim 1, characterized in that: The heating and drying process in step 3 is as follows: the spin-coated sample is placed on a heating table at 120°C and heated for 10 minutes to allow the remaining solvent to evaporate completely.

7. An infrared-controlled thin film material, characterized in that: The polystyrene protective layer treated by any one of the methods described in claims 1-6 can be stably used in a high-temperature environment of 250°C, and after neutral salt spray tests for 48h, 96h, and 144h, it can effectively protect the original infrared properties of the infrared modulated film material.

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