Ship-borne anti-corrosion and wave-absorbing integrated metasurface elastomer and preparation method thereof

Abstract

The invention discloses a ship-borne anti-corrosion and wave-absorbing integrated super-surface elastomer and further discloses a preparation method of the elastomer, and the preparation method comprises the following steps: S1, preparing an inner protection matrix by using an anti-corrosion filler, an antioxidant, polyether amine and isocyanate; s2, preparing conductive ink by using dielectric loss filler, magnetic loss filler, a photosensitive polymer, a photoinitiator, a reactive diluent and a dispersing agent, and coating the conductive ink on the surface of the inner protection substrate in a patterned manner to form a super-surface wave-absorbing layer; s3, preparing an outer hydrophobic layer outside the metasurface wave-absorbing layer to obtain a metasurface elastomer; and S4, one side of the inner protection base body of the super-surface elastomer is attached to the outer surface of the ship electronic device, and anti-corrosion and wave-absorbing integrated packaging is achieved. The super-surface elastomer has the functions of corrosion prevention and wave absorption, is suitable for packaging and electromagnetic protection of devices such as ship-borne communication nodes and high-frequency electronic modules, and can remarkably improve the reliability and prolong the service life of the devices in a complex marine environment.

Description

Technical Field

[0001] This invention belongs to the field of electronic device packaging technology, specifically relating to a shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer. This invention also relates to a method for preparing the metasurface elastomer. Background Technology

[0002] Shipborne electronic components integrate multiple key systems such as radar, communication, navigation, and electronic countermeasures. As the core of modern naval equipment, their reliability directly determines the overall effectiveness of the ship's combat system. However, due to prolonged exposure to extreme marine environments such as high salt spray, high humidity, alternating temperatures, and high-frequency mechanical vibrations, electronic components are susceptible to direct corrosion, leading to short circuits and performance degradation. Simultaneously, the complex electromagnetic interference generated by the densely packed electronic equipment on board easily causes signal scattering and internal system interference, severely weakening the overall effectiveness of the combat system. Statistics show that corrosion and electromagnetic interference contribute 38% and 25% respectively to shipborne electronic system failures, far exceeding the failure rates of similar land-based systems.

[0003] Currently, the common approach to protecting shipborne electronic devices is to coat their surfaces with epoxy resin, silicone, or polyurethane coatings. While these provide basic moisture protection and electrical insulation, their overall performance is insufficient to meet the demands of the complex and ever-changing shipborne environment. More importantly, traditional coatings primarily focus on physical isolation and do not possess electromagnetic wave absorption capabilities. In recent years, the rise of metamaterials technology has provided a new technological path for the multifunctional protection of electronic devices. These materials, based on precisely designed periodic surface array structures, can effectively absorb and control electromagnetic waves in specific bands and exhibit potential for programmability and reconfigurability. However, most existing metasurface absorbing materials are based on rigid ceramics, fiber composites, or multilayer thin-film systems with metallic dielectrics. Their flexibility is severely insufficient, making them unable to withstand thermal shock and vibration fatigue on the ship's deck, thus greatly limiting their application under actual shipborne conditions. Therefore, developing a metasurface elastomer material that can effectively prevent marine corrosion, absorb electromagnetic waves, and possess good elasticity is of significant practical importance for improving the operational reliability and lifespan of shipborne electronic devices. Summary of the Invention

[0004] The purpose of this invention is to provide a metasurface elastomer that integrates shipborne corrosion protection and wave absorption, which has both corrosion protection and wave absorption functions. It is suitable for the packaging and electromagnetic protection of shipborne communication nodes, high-frequency electronic modules and other devices, and can significantly improve their reliability and service life in complex marine environments.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned metasurface elastomer.

[0006] The technical solution adopted in this invention is a method for preparing a metasurface elastomer that integrates shipborne corrosion protection and wave absorption, specifically implemented according to the following steps: S1, an inner protective matrix is ​​prepared using corrosion-resistant fillers, antioxidants, polyetheramines, and isocyanates; S2, conductive ink is prepared by using dielectric loss filler, magnetic loss filler, photosensitive polymer, photoinitiator, reactive diluent and dispersant, and the conductive ink is patterned and coated on the surface of the inner protective substrate to form a metasurface absorbing layer; S3, an outer hydrophobic layer is prepared outside the metasurface absorbing layer to obtain a metasurface elastomer; S4 integrates the inner protective substrate of the metasurface elastomer with the outer surface of the ship's electronic components to achieve a unified encapsulation for corrosion protection and wave absorption.

[0007] The invention is further characterized by: Step 1 is as follows: The corrosion-resistant filler and antioxidant are dispersed in a solvent and ultrasonically dispersed for 10-20 minutes. Then, polyetheramine is added under N2 atmosphere and mixed evenly. Isocyanate is then slowly added and reacted at 10-20°C for 2-3 hours. After the reaction is completed, the reaction solution is poured into a mold and cured at 60-80°C for 1-2 hours to obtain an inner protective matrix with a thickness of 0.5-1.0 mm.

[0008] The corrosion-resistant filler is one or a mixture of glass flakes, precipitated barium sulfate, and mica powder, with a particle size of 5-10 μm, and its addition amount is 5%-10% of the mass of polyetheramine; The antioxidant is one or a mixture of hindered phenolic and phosphite antioxidants, and its addition amount is 3% to 5% of the mass of polyetheramine; The solvent is N-methylpyrrolidone, N,N-dimethylformamide, or dimethyl sulfoxide; The polyetheramine is one or a mixture of two of D-2000 or D-4000; The isocyanate is one or a mixture of aliphatic isocyanate trimer, toluene diisocyanate, and diphenylmethane diisocyanate; The total mass of polyetheramine and isocyanate is 70%-80% of the mass of solvent, and the molar ratio of isocyanate to amine is 1:(0.95~1.05).

[0009] Step 2 is as follows: Dielectric loss filler and magnetic loss filler are mixed evenly, and then photosensitive polymer, photoinitiator, reactive diluent and dispersant are added sequentially. The mixture is ultrasonically mixed at room temperature for 10-20 minutes to obtain conductive ink. The conductive ink is then patterned and coated onto the surface of the inner protective substrate using a 325-420 mesh screen printing plate, and then subjected to light at 365-405 nm and an intensity of 50-150 mW / cm.2 UV light irradiation for 20–60 seconds cures to form a metasurface absorbing layer with a thickness of 15–30 μm.

[0010] The metasurface absorbing layer has a periodic pattern structure, which is selected from one or more of the following: square patch array, circular resonant ring array, cross-shaped structure array, and open ring structure array. The period of the unit of the periodic pattern structure is scaled proportionally to the free space wavelength corresponding to the target absorption frequency band, so that the metasurface absorbing layer generates electromagnetic resonance absorption in the 2-18 GHz and 0.1-1 THz frequency bands.

[0011] The composition and mass percentage of each component in the conductive ink are as follows: The dielectric loss filler is one or more of carbon nanotubes, graphene, and micene, with a mass percentage of 4 to 10 wt% and a size of 50 to 100 nm. The magnetic loss filler is one or more of ferric oxide, iron oxide, and iron cobalt ferrite, with a mass percentage of 9-15 wt% and a particle size of 50-100 nm. The photosensitive polymer is polyurethane acrylate, with a mass percentage of 60–80 wt%. The photoinitiator is Irgacure TPO, with a mass percentage of 1–3 wt%. The reactive diluent is TPGDA, with a mass percentage of 5-10 wt%. The dispersant is BYK-110, with a mass percentage of 1-2 wt%.

[0012] Step 3 specifically involves: Diluted fluorosilicone modified resin or a solution containing perfluoroalkyl polysiloxane is applied to the outside of the metasurface absorbing layer by spin coating or aerosol spraying to form a uniform matte or iridescent interference film. Then, it is heat-cured at 80-120℃ for 10-30 minutes to form an outer hydrophobic layer with a thickness of 5-8μm, thus obtaining the metasurface elastomer.

[0013] In spin coating or aerosol spraying, spray 2 to 3 cross-passes at a speed of 5 to 10 mm / s, with an interval of 10 to 30 seconds between each pass, and the wet film thickness of the coating is 15 to 20 μm.

[0014] Another technical solution adopted in this invention is a shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer, which is prepared by the above method.

[0015] The beneficial effects of this invention are: (1) This invention innovatively integrates corrosion protection and electromagnetic wave absorption functions into a single elastomer structure. Through the synergistic design of the inner protective matrix, the supersurface wave-absorbing layer and the outer hydrophobic layer, multifunctional integrated protection is achieved, which effectively solves the technical problem of the single function of traditional protective materials. (2) The three-layer composite structure of the metasurface elastomer of the present invention forms a complete protection system. The inner protective matrix significantly improves the anti-aging performance of the elastomer through the synergistic effect of corrosion-resistant filler and antioxidant, and provides excellent mechanical buffering and moisture-proof sealing performance. The metasurface absorbing layer, through the synergistic effect of periodic metasurface structure and dielectric / magnetic loss filler, enables the elastomer to exhibit wide-band and high-efficiency electromagnetic wave absorption characteristics. The screen printing and photocuring process is used to achieve precise control of the metasurface patterning. The preparation process is simple and fast, with good process applicability and industrialization potential. The outer hydrophobic layer effectively isolates salt spray corrosion, so that the elastomer can maintain stable performance in the harsh marine environment of high temperature and high salt, ensuring the stability of the wave absorption performance during long-term service, and providing a strong guarantee for the reliable operation of shipborne electronic devices in complex marine environments. (3) The outer hydrophobic layer, the outer wave-absorbing layer and the inner protective matrix of the metasurface elastomer of the present invention form an impedance gradient from the outside to the inside, which enables electromagnetic waves to couple step by step at the incident interface before entering the interior of the structure, effectively reducing interface reflection and significantly improving absorption efficiency. In addition, during the preparation of the inner protective matrix, a scheme of synergistic dispersion of corrosion-resistant fillers and antioxidants is adopted, and a step-by-step process of low-temperature stirring and medium-temperature curing is used, which not only improves the stability of the polyurea matrix structure but also ensures the uniformity of matrix performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the three-layer structure of the metasurface elastomer of the present invention; Figure 2 This is a schematic diagram of the periodic absorbing pattern in the metasurface elastomer of the present invention; Figure 3 The graph shows the hydrophobicity test results of the elastomers prepared in Example 1 and Comparative Examples 1, 3, and 4 of this invention. Figure 4 The stress-strain curves are those of the elastomers prepared in Example 1 and Comparative Examples 4 and 5 of this invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] The shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer of this invention has a multi-layer composite structure, such as... Figure 1As shown, it comprises an inner protective substrate, a metasurface absorbing layer, and an outer hydrophobic layer arranged sequentially from the inside out. The inner protective substrate is a modified polyurea elastomer, which coats the outer surface of the electronic device. It is made by polymerization of isocyanate, polyetheramine, corrosion-resistant filler, and antioxidant, and possesses excellent mechanical and corrosion-resistant properties. The metasurface absorbing layer is a periodic pattern formed on the surface of the inner protective substrate through screen printing and photopolymerization processes. Combined with dielectric / magnetic loss fillers such as graphene and iron(III) oxide, it achieves broadband electromagnetic wave absorption. The outer hydrophobic layer is based on fluorosilicone modified resin, which effectively isolates salt spray and moisture, ensuring the long-term stability of the wave absorption performance in a marine environment.

[0019] The preparation method of the shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer of the present invention is carried out according to the following steps: S1, Preparation of the inner protective matrix - polyurea elastomer matrix: The corrosion-resistant filler and antioxidant are dispersed in a solvent and ultrasonically dispersed for 10–20 min. Then, polyetheramine is added under a nitrogen atmosphere and mixed thoroughly. Isocyanate is then slowly added to the system and reacted at 10–20 °C for 2–3 h. After the reaction is complete, the reaction solution is poured into a mold and cured at 60–80 °C for 1–2 h to obtain an inner protective matrix with a thickness of 0.5–1.0 mm.

[0020] The corrosion-resistant filler improves the barrier properties and corrosion resistance of the polyurea matrix. Its addition amount is 5%–10% of the polyetheramine mass, and it is selected from one or more of surface-treated glass flakes, precipitated barium sulfate, and mica powder, with a particle size of 5–10 μm. Furthermore, to prevent photo-oxidation and thermal oxidation of the polyurea matrix during UV curing and long-term service, an antioxidant is introduced at 3%–5% of the polyetheramine mass. This antioxidant is one or a mixture of hindered phenols, phosphites, or both. By effectively capturing free radicals and peroxides, it ensures the long-term service life of the matrix.

[0021] The solvent is one of N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO); the polyetheramine is one or more of D-2000 or D-4000; the isocyanate is one or more of aliphatic isocyanate trimer (HDI trimer), toluene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI); the total mass of the polyetheramine and the isocyanate is 70%-80% of the mass of the solvent, and the molar ratio of isocyanate to amine is 1:(0.95~1.05).

[0022] S2, Preparation of metasurface absorbing layer: Dielectric loss filler and magnetic loss filler are mixed evenly, and then photosensitive polymer, photoinitiator, reactive diluent and dispersant are added sequentially. The mixture is ultrasonically mixed at room temperature for 10–20 min to obtain conductive ink. The conductive ink is patterned and coated onto the surface of the inner protective substrate obtained in step 1 using screen printing, and then exposed to light at 365–405 nm and an intensity of 50–150 mW / cm². 2 UV light irradiation for 20–60 seconds cures to form a metasurface absorbing layer.

[0023] The screen printing uses a 325-420 mesh screen with a printing thickness of 15-30 μm.

[0024] like Figure 2 As shown, the metasurface absorbing layer has a periodic pattern structure, which is selected from one or more of the following: square patch array, circular resonant ring array, cross-shaped structure array, and open ring structure array. The period of the unit of the periodic pattern is scaled proportionally to the free space wavelength corresponding to the target absorption frequency band, so that the metasurface absorbing layer generates electromagnetic resonance absorption in the 2-18 GHz and 0.1-1 THz frequency bands.

[0025] In addition, the composition and mass percentage of each component in the conductive ink are as follows: The dielectric loss filler is one or more of carbon nanotubes, graphene, and micene, with a mass percentage of 4–10 wt% and a size of 50–100 nm; the magnetic loss filler is one or more of ferric oxide, magnetite, and iron cobalt ferrite, with a mass percentage of 9–15 wt% and a particle size of 50–100 nm; the photosensitive polymer is polyurethane acrylate, with a mass percentage of 60–80 wt%; the photoinitiator is Irgacure TPO, with a mass percentage of 1–3 wt%; the reactive diluent is TPGDA, with a mass percentage of 5–10 wt%; and the dispersant is BYK-110, with a mass percentage of 1–2 wt%.

[0026] Preferably, graphene (GO) and iron oxide are selected as microwave absorbing fillers.

[0027] S3, coated with an outer hydrophobic layer: After purging the surface dust of the metasurface substrate layer obtained in step S2 with clean, dry air or nitrogen, a diluted fluorosilicone modified resin or a solution containing perfluoroalkyl polysiloxane is applied to the outside of the metasurface absorbing layer by spin coating or aerosol spraying. Specifically, 2-3 cross-passes are sprayed at a speed of 5-10 mm / s, with a 10-30 second interval between each pass to allow solvent evaporation. The wet film thickness of the coating is 15-20 μm, forming a uniform matte or iridescent interference film layer on the outside of the metasurface absorbing layer, without any sagging or liquid accumulation. Then, it is heat-cured in an oven at 80-120°C for 10-30 minutes to completely remove residual solvent and strengthen the coating adhesion, ultimately forming a 5-8 μm outer hydrophobic layer with a water contact angle greater than 110°, thus obtaining the metasurface elastomer.

[0028] Preferably, the hydrophobic coating solution is from the Dow Chemical DOWSIL™ OFS-2300 series.

[0029] S4, Electronic Component Packaging: The inner protective substrate side of the obtained metasurface elastomer is bonded to the outer surface of the ship's electronic devices to achieve integrated encapsulation for corrosion protection and wave absorption.

[0030] Example 1: S1. Add 1.3g of glass flakes and 0.7g of antioxidant (0.4g of antioxidant 1010 + 0.3g of antioxidant 168) to 25mL of DMSO and ultrasonically disperse for 10 minutes. Then, add 17.7g of D-2000 under N2 atmosphere and disperse evenly. Slowly add 2.95g of isocyanate N3300 and mix at 15℃ for 3 hours. After the reaction is complete, pour into a mold and cure at 60℃ for 2 hours to obtain a polyurea elastomer matrix with a thickness of 1mm.

[0031] S2, mix 0.7g graphene (GO) and 1.2g iron oxide in 10mL of ethanol, sonicate for 10min to ensure uniform dispersion, then add 7g polyurethane acrylate, 0.2g Irgacure TPO photocuring agent, 0.75g TPGDA reactive diluent, and 0.15g BYK-110 dispersant, sonicate again for 10min to ensure uniform mixing, and adjust the viscosity to approximately 1000cP to obtain conductive ink. Then, screen print using a 325-420 mesh screen to form a cross-shaped array pattern on the surface of the inner protective substrate, and then print at 395nm wavelength and 70mW / cm² light intensity. 2 The photosensitive polymer is cured by irradiation under ultraviolet light for 30 seconds to ensure complete curing and form a 25μm metasurface absorbing layer.

[0032] S3. Dilute Dow Chemical's DOWSIL™ OFS-2300 stock solution to a 2% concentration. Apply the solution via aerosol spraying at a speed of 8 mm / s in three overlapping passes, with a 30-second interval between each pass to allow for solvent evaporation. Apply the solution to the surface of the metasurface absorbing layer. Heat cure in a 120°C oven for 10 minutes to thoroughly remove residual solvent and enhance coating adhesion, ultimately forming a 5 μm protective layer.

[0033] Example 2: S1. Add 1.2g of glass flakes and 0.66g of antioxidant 1076 to 25mL of DMSO and ultrasonically disperse for 10 minutes. Then, add 16.5g of D-2000 under N2 atmosphere and disperse evenly. Slowly add 2.75g of isocyanate N3300 and mix at 20℃ for 2.5h. After the reaction is complete, pour into a mold and cure at 70℃ for 1.5h to obtain a polyurea elastomer matrix with a thickness of 0.75mm.

[0034] S2, mix 0.6g graphene (GO) and 1.3g iron oxide in 10mL of ethanol, and sonicate for 10min to ensure uniform dispersion. Then add 6.5g polyurethane acrylate, 0.1g Irgacure TPO photocuring agent, 0.7g TPGDA reactive diluent, and 0.2g BYK-110 dispersant, and sonicate again for 10min to ensure uniform mixing. Adjust the viscosity to approximately 1000cP to obtain conductive ink. Next, screen print using a 325-420 mesh screen to form a cross-shaped array pattern on the surface of the inner protective substrate. Then, print at 365nm wavelength and 50mW / cm² light intensity. 2 The photosensitive polymer is cured by irradiation under ultraviolet light for 30 seconds to ensure complete curing and form a 30μm metasurface absorbing layer.

[0035] S3. Dilute Dow Chemical's DOWSIL™ OFS-2300 stock solution to a 2% concentration. Apply the solution via aerosol spraying at a speed of 5 mm / s in three overlapping passes, with a 30-second interval between each pass to allow for solvent evaporation. Apply the solution to the surface of the metasurface absorbing layer. Heat cure in an oven at 80°C for 25 minutes to completely remove residual solvent and enhance coating adhesion, ultimately forming a 5 μm protective layer.

[0036] Example 3: S1, 1.4g of glass flakes and 0.76g of antioxidant 168 were added to 25mL of DMSO and ultrasonically dispersed for 10 minutes. Then, 18.9g of D-2000 was added under N2 atmosphere and dispersed evenly. Then, 3.14g of isocyanate N3300 was slowly added and mixed at 10℃ for 2 hours. After the reaction was completed, the mixture was poured into a mold and cured at 60℃ for 2 hours to obtain a polyurea elastomer matrix with a thickness of 0.5mm.

[0037] S2, mix 0.8g graphene (GO) and 1.4g iron oxide in 10mL of ethanol, and sonicate for 10min to ensure uniform dispersion. Then add 7.5g polyurethane acrylate, 0.3g Irgacure TPO photocuring agent, 0.8g TPGDA reactive diluent, and 0.2g BYK-110 dispersant, and sonicate again for 10min to ensure uniform mixing. Adjust the viscosity to approximately 1000cP to obtain conductive ink. Next, screen print using a 325-420 mesh screen to form a cross-shaped array pattern on the surface of the inner protective substrate. Then, print at 365nm wavelength and 150mW / cm² light intensity. 2 The photosensitive polymer is cured by irradiation under ultraviolet light for 30 seconds to ensure complete curing and form a 30μm metasurface absorbing layer.

[0038] S3. Dilute Dow Chemical's DOWSIL™ OFS-2300 stock solution to a 2% concentration. Apply the solution via aerosol spraying at a speed of 5 mm / s in three overlapping passes, with a 30-second interval between each pass to allow for solvent evaporation. Apply the solution to the surface of the metasurface absorbing layer. Heat cure in an oven at 110°C for 10 minutes to thoroughly remove residual solvent and enhance coating adhesion, ultimately forming a 5 μm protective layer.

[0039] Example 4: S1, 0.89g of precipitated barium sulfate and 0.53g of antioxidant (0.21g antioxidant 1076 + 0.32g antioxidant 12) were added to 25mL of DMSO and ultrasonically dispersed for 10 minutes. Then, 17.7g of D-2000 was added under N2 atmosphere and dispersed evenly. 2.95g of isocyanate N3300 was slowly added and mixed at 15℃ for 3 hours. After the reaction was completed, the mixture was poured into a mold and cured at 60℃ for 2 hours to obtain a polyurea elastomer matrix with a thickness of 1mm.

[0040] S2, mix 0.8g graphene (GO) and 1.4g iron oxide in 10mL of ethanol, and sonicate for 10min to ensure uniform dispersion. Then add 7.5g polyurethane acrylate, 0.3g Irgacure TPO photocuring agent, 0.8g TPGDA reactive diluent, and 0.2g BYK-110 dispersant, and sonicate again for 10min to ensure uniform mixing. Adjust the viscosity to approximately 1000cP to obtain conductive ink. Next, screen print using a 325-420 mesh screen to form a cross-shaped array pattern on the surface of the inner protective substrate. Then, print at 365nm wavelength and 150mW / cm² light intensity. 2 The photosensitive polymer is cured by irradiation under ultraviolet light for 30 seconds to ensure complete curing and form a 30μm metasurface absorbing layer.

[0041] S3. Dilute Dow Chemical's DOWSIL™ OFS-2300 stock solution to a 2% concentration. Apply the solution via aerosol spraying at a speed of 10 mm / s in three overlapping passes, with a 30-second interval between each pass to allow solvent evaporation. Apply the solution to the surface of the metasurface absorbing layer. Heat cure in an oven at 120°C for 25 minutes to completely remove residual solvent and enhance coating adhesion, ultimately forming a 7 μm protective layer.

[0042] Example 5: S1, 1.77g of precipitated barium sulfate and 0.89g of antioxidant (0.56g of antioxidant 1076 + 0.33g of antioxidant 12) were added to 25mL of DMSO and ultrasonically dispersed for 10 minutes. Then, 17.7g of D-2000 was added under N2 atmosphere and dispersed evenly. 2.95g of isocyanate N3300 was slowly added and mixed at 15℃ for 3 hours. After the reaction was completed, the mixture was poured into a mold and cured at 60℃ for 2 hours to obtain a polyurea elastomer matrix with a thickness of 1mm.

[0043] S2, mix 0.8g graphene (GO) and 1.4g iron oxide in 10mL of ethanol, and sonicate for 10min to ensure uniform dispersion. Then add 7.5g polyurethane acrylate, 0.3g Irgacure TPO photocuring agent, 0.8g TPGDA reactive diluent, and 0.2g BYK-110 dispersant, and sonicate again for 10min to ensure uniform mixing. Adjust the viscosity to approximately 1000cP to obtain conductive ink. Next, screen print using a 325-420 mesh screen to form a cross-shaped array pattern on the surface of the inner protective substrate. Then, print at 365nm wavelength and 150mW / cm² light intensity. 2 The photosensitive polymer is cured by irradiation under ultraviolet light for 30 seconds to ensure complete curing and form a 30μm metasurface absorbing layer.

[0044] S3. Dilute Dow Chemical's DOWSIL™ OFS-2300 stock solution to a 2% concentration. Apply the solution via aerosol spraying at a speed of 10 mm / s in three overlapping passes, with a 30-second interval between each pass to allow for solvent evaporation. Apply the solution to the surface of the metasurface absorbing layer. Heat cure in an oven at 120°C for 25 minutes to completely remove residual solvent and enhance coating adhesion, ultimately forming an 8 μm protective layer.

[0045] Example 6: S1. Add 1.3g of glass flakes and 0.7g of antioxidant (0.4g of antioxidant 1010 + 0.3g of antioxidant 168) to 25mL of DMSO and ultrasonically disperse for 10 minutes. Then, add 17.7g of D-2000 under N2 atmosphere and disperse evenly. Slowly add 2.95g of isocyanate N3300 and mix at 15℃ for 3 hours. After the reaction is complete, pour into a mold and cure at 60℃ for 2 hours to obtain a polyurea elastomer matrix with a thickness of 1mm.

[0046] S2, mix 0.7g graphene (GO) and 1.2g iron oxide in 10mL ethanol, sonicate for 10min to ensure uniform dispersion, then add 7g polyurethane acrylate, 0.2g Irgacure TPO photocuring agent, 0.75g TPGDA reactive diluent, and 0.15g BYK-110 dispersant, sonicate again for 10min to ensure uniform mixing, and adjust the viscosity to approximately 1000cP to obtain conductive ink. Then, screen print using a 325-420 mesh screen to form a cross-shaped array pattern on the surface of the inner protective substrate, and then print at a wavelength of 405nm and an intensity of 150mW / cm². 2 The photosensitive polymer is cured by irradiation under ultraviolet light for 30 seconds to ensure complete curing and form a 30μm metasurface absorbing layer.

[0047] S3. Dilute Dow Chemical's DOWSIL™ OFS-2300 stock solution to a 2% concentration. Apply the solution via aerosol spraying at a speed of 10 mm / s in three overlapping passes, with a 30-second interval between each pass to allow solvent evaporation. Apply the solution to the surface of the metasurface absorbing layer. Heat cure in an oven at 120°C for 30 minutes to thoroughly remove residual solvent and enhance coating adhesion, ultimately forming a 5 μm protective layer.

[0048] Comparative Example 1: This comparative example is basically the same as Example 1, except that no corrosion-resistant filler and antioxidant were added in step 1.

[0049] Comparative Example 2: This comparative example is basically the same as Example 1, except that no antioxidant was added in step 1.

[0050] Comparative Example 3: This comparative example is basically the same as Example 1, except that step S3 was not performed, that is, the prepared elastomer does not have an outer hydrophobic layer.

[0051] Comparative Example 4: This comparative example is basically the same as Example 1, except that only step S1 was performed, that is, the elastomer produced only has an inner protective matrix.

[0052] Comparative Example 5: This comparative example is basically the same as Example 1, except that only step S2 was performed, that is, the elastomer produced only has a metasurface absorbing layer.

[0053] The following performance tests were performed on the materials prepared in Examples 1-6 and Comparative Examples 1-5: Table 1 shows the test results of the mechanical properties of each material: Table 1 Mechanical stability test results

[0054] As can be seen from Table 1, the metasurface elastomer of the present invention has added corrosion-resistant fillers and antioxidants and adopted a three-layer composite structure. Compared with the elastomers in the comparative examples that did not add corrosion-resistant fillers and antioxidants or did not have a complete three-layer structure, it has higher tensile strength and elastic modulus, improves overall mechanical stability, and provides a basis for long-term service.

[0055] Table 2 shows the water contact angle test results for each material: Table 2 Water contact angle test results

[0056] In addition, the hydrophobic properties of different elastomers were tested using a contact angle meter, and the results are as follows: Figure 3 As shown, (a)-(d) correspond to the elastomers prepared in Comparative Example 1, Comparative Example 2, Comparative Example 4 and Example 1, respectively.

[0057] Combining the data in Table 2 with Figure 3 It can be seen that although the elastomer in Comparative Example 4 only has an inner protective matrix, it still exhibits good hydrophobic properties due to the combined effect of its stable polyurea network and filler. The metasurface structure of Comparative Example 5 has slightly poor hydrophobicity due to the large number of hydrophilic functional groups on its surface. Although the elastomers in Comparative Examples 1 and 2 did not have corrosion-resistant fillers or antioxidants, their thin hydrophobic layers on their surfaces still gave them good hydrophobicity. The three-layer structure of the elastomers in Examples 1, 2, and 4 works synergistically to exhibit the best hydrophobicity, which can adapt to complex marine environments and protect the stable operation of electronic devices.

[0058] Cyclic salt spray / UV testing was performed on each material. The specific procedure was as follows: a 5% NaCl solution was sprayed onto the elastomer surface at 35℃ and held for 15 minutes, then dried at 40℃ for 75 minutes, followed by standing in 70℃ water vapor for 120 minutes, and finally dried in sunlight. This process was repeated 5 times. The mass changes before and after the test are shown in Table 3. Table 3. Mass changes after cyclic salt spray / UV testing

[0059] As shown in Table 3, the elastomers in Comparative Examples 1 and 2, which have hydrophobic layers, can slow down corrosion by reducing bacterial adhesion in the initial stage. However, they cannot completely resist complex salt spray environments during repeated tests. Furthermore, the elastomer in Comparative Example 2, which contains corrosion-resistant fillers, performs slightly better than Comparative Example 1. This is because the corrosion-resistant fillers within the matrix play a role. However, observation of the elastomer morphology after testing reveals severe damage to its metasurface structure, with fine cracks and a small number of bubbles appearing in the internal matrix. In Comparative Example 3, the antioxidant and corrosion-resistant fillers work synergistically to improve the elastomer's corrosion resistance. However, due to the lack of a surface hydrophobic layer, the corrosion rate is high in the initial stage of testing. The rate of corrosion reduction was the fastest, and the metasurface structure almost disappeared, with obvious internal cracks. In Comparative Example 4, the stable isocyanate structure in the inner protective matrix, under the combined action of antioxidants and corrosion-resistant fillers, has beneficial anti-corrosion properties and a low mass reduction rate, proving that it has a protective effect when closely attached to the surface of electrical components. The metasurface structure of Comparative Example 5 performed the worst in the cyclic salt spray / UV test because its surface has a large number of hydrophilic functional groups, which cannot exist stably in the marine environment for a long time. In contrast, the three-layer structure of the elastomer in Example 6 can effectively combine the advantages of each layer structure. After repeated testing, almost no corrosion was observed, and the outer hydrophobic layer effectively protected the metasurface structure.

[0060] like Figure 4 As shown, the stress-strain curves of the elastomers prepared in Example 1, Comparative Example 4, and Comparative Example 5 are shown. It can be seen that compared with the single-layer elastomers in Comparative Examples 4 and 5, the three-layer structure elastomer in Example 1 has the highest fracture strength of 51 MPa, exhibiting excellent load-bearing capacity, high elongation, and good flexibility, and can adapt to deformation conditions such as bending and thermal expansion and contraction.

Claims

1. A method for preparing a shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer, characterized in that, The specific steps are as follows: S1, an inner protective matrix is ​​prepared using corrosion-resistant fillers, antioxidants, polyetheramines, and isocyanates; S2, conductive ink is prepared by using dielectric loss filler, magnetic loss filler, photosensitive polymer, photoinitiator, reactive diluent and dispersant, and the conductive ink is patterned and coated on the surface of the inner protective substrate to form a metasurface absorbing layer; S3, an outer hydrophobic layer is prepared outside the metasurface absorbing layer to obtain a metasurface elastomer; S4 integrates the inner protective substrate of the metasurface elastomer with the outer surface of the ship's electronic components to achieve a unified encapsulation for corrosion protection and wave absorption.

2. The method for preparing the integrated metasurface elastomer for shipborne corrosion protection and wave absorption according to claim 1, characterized in that, Step 1 is as follows: The corrosion-resistant filler and antioxidant are dispersed in a solvent and ultrasonically dispersed for 10-20 minutes. Then, polyetheramine is added under N2 atmosphere and mixed evenly. Isocyanate is then slowly added and reacted at 10-20°C for 2-3 hours. After the reaction is completed, the reaction solution is poured into a mold and cured at 60-80°C for 1-2 hours to obtain an inner protective matrix with a thickness of 0.5-1.0 mm.

3. The method for preparing the shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer according to claim 2, characterized in that, The corrosion-resistant filler is one or a mixture of glass flakes, precipitated barium sulfate, and mica powder, with a particle size of 5-10 μm, and its addition amount is 5%-10% of the mass of polyetheramine; The antioxidant is one or a mixture of hindered phenolic and phosphite antioxidants, and its addition amount is 3% to 5% of the mass of polyetheramine; The solvent is N-methylpyrrolidone, N,N-dimethylformamide, or dimethyl sulfoxide; The polyetheramine is one or a mixture of two of D-2000 or D-4000; The isocyanate is one or a mixture of aliphatic isocyanate trimer, toluene diisocyanate, and diphenylmethane diisocyanate; The total mass of the polyetheramine and isocyanate is 70%-80% of the mass of the solvent, and the molar ratio of isocyanate to amine is 1:(0.95~1.05).

4. The method for preparing the shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer according to claim 1, characterized in that, Step 2 is as follows: Dielectric loss filler and magnetic loss filler are mixed evenly, and then photosensitive polymer, photoinitiator, reactive diluent and dispersant are added sequentially. The mixture is ultrasonically mixed at room temperature for 10-20 minutes to obtain conductive ink. The conductive ink is then patterned and coated onto the surface of the inner protective substrate using a 325-420 mesh screen printing plate, and then subjected to light at 365-405 nm and an intensity of 50-150 mW / cm. 2 UV light irradiation for 20–60 seconds cures to form a metasurface absorbing layer with a thickness of 15–30 μm.

5. The method for preparing the shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer according to claim 4, characterized in that, The metasurface absorbing layer has a periodic pattern structure, which is selected from one or more of the following: square patch array, circular resonant ring array, cross-shaped structure array, and open ring structure array. The period of each unit of the periodic pattern structure is scaled proportionally to the free space wavelength corresponding to the target absorption frequency band, so that the metasurface absorbing layer generates electromagnetic resonance absorption in the 2-18 GHz and 0.1-1 THz frequency bands.

6. The method for preparing the shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer according to claim 4, characterized in that, The composition and mass percentage of each component in the conductive ink are as follows: The dielectric loss filler is one or more of carbon nanotubes, graphene, and MICRE, with a mass percentage of 4-10 wt% and a size of 50-100 nm. The magnetic loss filler is one or more of ferric oxide, iron oxide, and iron cobalt ferrite, with a mass percentage of 9-15 wt% and a particle size of 50-100 nm. The photosensitive polymer is polyurethane acrylate, with a mass percentage of 60-80 wt%. The photoinitiator is Irgacure TPO, with a mass percentage of 1–3 wt%. The active diluent is TPGDA, with a mass percentage of 5-10 wt%. The dispersant is BYK-110, with a mass percentage of 1 to 2 wt%.

7. The method for preparing the shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer according to claim 1, characterized in that, Step 3 specifically involves: Diluted fluorosilicone modified resin or a solution containing perfluoroalkyl polysiloxane is applied to the outside of the metasurface absorbing layer by spin coating or aerosol spraying to form a uniform matte or iridescent interference film. Then, it is heat-cured at 80-120℃ for 10-30 minutes to form an outer hydrophobic layer with a thickness of 5-8μm, thus obtaining the metasurface elastomer.

8. The method for preparing the shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer according to claim 7, characterized in that, In spin coating or aerosol spraying, spray 2 to 3 cross-passes at a speed of 5 to 10 mm / s, with an interval of 10 to 30 seconds between each pass, and the wet film thickness of the coating is 15 to 20 μm.

9. A shipborne anti-corrosion and wave-absorbing integrated metasurface elastomer, characterized in that, It is prepared by the method described in any one of claims 1-8.

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