Surface in-situ MOF (Metal Organic Framework) modified organic silicon photo-thermal anti-icing coating and preparation method thereof
By in situ growing MOF nanoparticles on the surface of the silicone coating, a surface in situ MOF-modified silicone photothermal anti-icing coating is formed, which solves the problems of high energy consumption, environmental pollution and limited effect of traditional anti-icing methods, achieves excellent anti-icing performance at low temperatures, reduces the freezing temperature and improves hydrophobicity.
Patent Information
- Application Number
- CN202511064719.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-09-16
AI Technical Summary
Existing technologies are difficult to effectively prevent icing. Traditional methods have problems such as high energy consumption, environmental pollution and limited effects. Traditional coating technologies lack durability and environmental friendliness in low-temperature environments.
By in situ growing MOF nanoparticles on the surface of the silicone coating, a surface in situ MOF-modified silicone photothermal anti-icing coating is formed, which improves the hydrophobicity and photothermal properties of the coating, reduces the freezing temperature, delays the freezing time, and quickly melts frost under light.
It achieves excellent anti-icing performance at low temperatures, reduces the freezing temperature, increases the water contact angle, extends the delayed freezing time, and reduces the ice adhesion strength, and has the ability of active photothermal deicing.
Smart Images
Figure CN120648378A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of organosilicon photothermal anti-icing coatings, and in particular to a method for preparing an organosilicon photothermal anti-icing coating with an in-situ MOF-modified surface. Background Art
[0002] Icing poses a serious threat to the industrial, aviation, rail, and wind power sectors, directly threatening the safe operation of equipment and the proper functioning of systems, and can even lead to severe economic losses and casualties. When aircraft fly at high altitudes, moisture in the air can easily freeze and adhere to key components such as wings, propellers, and landing gear, disrupting aerodynamic performance, increasing drag, reducing lift, and even causing a loss of lift and difficulty in flight. Wing ice, particularly during takeoff and landing, can cause emergencies, increase pilot workload, and even lead to accidents. Ice can also clog aircraft sensors and air intakes, disrupting the proper functioning of flight systems. These conditions can result in flight delays, diversions, or even tragic accidents. Icing on rails and signal systems can cause signal failures, impacting train scheduling and operational safety. Icing on wheels and tracks can cause trains to skid or extend braking distances, increasing the risk of accidents. Furthermore, if icing causes electrical components in railway signal systems to short-circuit or malfunction, it can disrupt train scheduling and even lead to rear-end collisions or derailments. If excessive snow accumulation or persistent low temperatures in winter cause railways to remain frozen for extended periods, rail transport may be forced to be interrupted, impacting the normal flow of people and goods. Wind turbine blades are prone to ice formation in cold and humid environments, causing the blade surface to become rough and uneven, disrupting their aerodynamic performance, reducing wind energy utilization efficiency, and even causing blade imbalance and vibration problems. Furthermore, ice formation may increase the weight of the blades, leading to increased mechanical loads and shortening the normal operating life of wind turbines. In extreme cases, ice formation may cause wind turbines to completely cease operation, resulting in significant economic losses. This is particularly true at offshore wind farms, where the combination of salt spray and sea breezes exacerbates the icing phenomenon, further exacerbating equipment corrosion and wear.
[0003] Icing problems in these areas not only lead to reduced equipment performance and threats to operational safety, but also cause serious economic losses and social impacts. Therefore, how to effectively prevent and resolve icing problems has become a core task to ensure the safe and efficient operation of these key areas. Traditional anti-icing methods, such as the use of anti-icing fluids, heating, and gas flow, can prevent icing to a certain extent, but these methods have obvious defects and limitations. For example, the use of anti-icing fluids, while simple and effective, may pollute the environment and, in some cases, may have a negative impact on product quality; heating antifreeze methods, while ensuring that the equipment temperature is above the freezing point, consumes a lot of energy and increases operating costs; gas flow technology is simple and easy to use, but its effect is limited in high humidity or extremely low temperature environments, making it difficult to fully resolve the icing problem.
[0004] As an effective means of defense, coating technology can prevent the occurrence of ice to a certain extent by coating specific anti-icing materials on the surface of the equipment, such as water-based coatings, thermal conductive coatings and super-hydrophobic coatings. However, these traditional coating technologies still have shortcomings in durability and environmental protection, and it is difficult to fundamentally solve the problem of ice. In low-temperature environments, photothermal coatings can optimize the conversion and distribution of thermal energy to keep the temperature of the equipment surface above the freezing point, effectively preventing the formation of ice. The present invention discloses a surface in-situ MOF-modified organosilicon photothermal anti-icing coating with excellent hydrophobic, photothermal and anti-icing properties. Summary of the Invention
[0005] The present invention provides a surface in-situ MOF-modified organosilicon photothermal anti-icing coating, which achieves excellent anti-icing performance at low temperatures, including increasing the water contact angle, lowering the freezing temperature, delaying the freezing time, and being able to quickly melt surface frost under light intensity.
[0006] A method for preparing an organosilicon photothermal anti-icing coating with in-situ MOF modified surface comprises the following steps:
[0007] Step S1: dissolving 1-3 parts of a metal salt hydrate in 50-75 parts of a diluent, then adding 50-80 parts of an organosiloxane, stirring at room temperature for 1-2 hours to obtain a coating with a viscosity of 0.1-0.5 Pa·s, spraying the coating on the surface of the substrate, and curing for 24 hours to obtain an unmodified organosilicon coating.
[0008] Step S2: dissolving 1-3 parts of the modifier in 10-20 parts of the solvent to form a modified solution, soaking the dried organic silicon coating in the modified solution for 3-6 hours, taking it out, and drying it at room temperature to obtain a MOF-modified organic silicon photothermal anti-icing coating.
[0009] In step S3, similarly, 1-3 parts of the modifier are dissolved in 5-10 parts of the solvent to form a modified solution, which is sprayed on the surface of the dried organic silicon coating. After the solvent evaporates, a MOF-modified organic silicon photothermal anti-icing coating is directly formed.
[0010] Furthermore, the hydrate of the metal salt described in step S1 is one or more of ferric nitrate nonahydrate, ferric chloride hexahydrate, cobalt nitrate hexahydrate, cobalt chloride hexahydrate, nickel nitrate hexahydrate, nickel chloride hexahydrate, copper nitrate trihydrate, copper chloride dihydrate, zinc nitrate hexahydrate, zinc chloride and hydrates thereof.
[0011] Furthermore, the diluent described in step S1 is one or more of tetrahydrofuran, toluene, xylene, ethyl acetate, and butyl acetate.
[0012] Furthermore, the organic siloxane raw material described in step S1 is one of the organic silicone emulsions selected from Dow Corning Sylgard 184 PDMS and Zhejiang Lingzhi New Materials Co., Ltd.
[0013] Furthermore, the modifier described in step S2 and step S3 is one of trimesic acid, terephthalic acid, 2-methylimidazole, benzimidazole, and 2-aminoimidazole.
[0014] Furthermore, the solvent in step S2 and step S3 is one of ethanol, ethyl acetate, and butyl acetate.
[0015] Another aspect of the present invention provides an organosilicon photothermal anti-icing surface with in-situ MOF modification prepared by the above preparation method.
[0016] This invention uses a seed-based growth method to in situ grow MOF nanoparticles on the surface of an organosilicon coating, creating an organosilicon photothermal anti-icing surface. The MOF nanoparticles on the organosilicon surface are distributed only in the top layer of the organosilicon coating and do not affect the overall internal performance of the organosilicon coating. MOF materials, nanomaterials composed of metal ions and organic ligands, can impart photothermal properties to the organosilicon coating surface. Furthermore, the MOF nanomaterial increases the surface roughness of the organosilicon coating, thereby enhancing the coating's surface hydrophobicity, which helps improve the coating's surface anti-icing properties.
[0017] The surface in-situ MOF-modified organosilicon photothermal anti-icing surface prepared by the present invention can be used for anti-icing of key surfaces in engineering steps, such as the surface of wind turbine blades. It can effectively reduce the ice adhesion strength between the ice layer and the coating, and realize active photothermal protection under the action of light, thereby comprehensively achieving higher anti-icing performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is the microscope image of Comparative Example 1.
[0019] Figure 2This is a microscope image of Example 1.
[0020] Figure 3 This is a microscope image of Example 2.
[0021] Figure 4 This is the infrared spectrum of Example 2.
[0022] Figure 5 This is the X-ray diffraction pattern of Example 2.
[0023] Figure 6 This is the contact angle diagram of Comparative Example 1.
[0024] Figure 7 The contact angle diagram of Example 2 DETAILED DESCRIPTION
[0025] The invention contents of the present invention are further described in detail below in the form of embodiments. The following contents are merely embodiments of the present invention, and all contents based on the invention contents of the present invention belong to the contents of the present invention.
[0026] Example 1
[0027] The preparation method of the organosilicon photothermal anti-icing coating with in-situ Fe-MOF modification on the surface is carried out according to the following steps:
[0028] 1) Dissolve 3 parts of ferric nitrate nonahydrate in 50 parts of tetrahydrofuran, then add 60 parts of Dow Corning Sylgard 184 PDMS and stir at room temperature for 1 hour. Then, add 6 parts of a matching curing agent and stir for another 0.5 hour. The resulting coating has a viscosity of 0.1-0.5 Pa·s. This coating is sprayed onto an aluminum sheet and cured for 24 hours to obtain an unmodified silicone coating.
[0029] 2) Dissolving 3 parts of 2-methylimidazole in 10 parts of ethanol to obtain a modified solution, soaking the dried organosilicon coating in the modified solution for 6 hours, removing it, and drying it at room temperature to obtain an organosilicon photothermal anti-icing coating with in situ Co-MOF modified surface.
[0030] Example 2
[0031] The preparation method of the surface in-situ Co-MOF modified organic silicon photothermal anti-icing coating is carried out according to the following steps:
[0032] 1) Dissolve 3 parts of cobalt nitrate hexahydrate in 50 parts of tetrahydrofuran, then add 60 parts of Dow Corning Sylgard 184 PDMS and stir at room temperature for 1 hour. Then, add 6 parts of a matching curing agent and stir for another 0.5 hour. The resulting coating has a viscosity of 0.1-0.5 Pa·s. This coating is sprayed onto an aluminum sheet and cured for 24 hours to obtain an unmodified silicone coating.
[0033] 2) 3 parts of benzimidazole imidazole were dissolved in 10 parts of ethanol to obtain a modified solution, and the dried organic silicon coating was immersed in the modified solution for 6 hours, taken out, and dried at room temperature to obtain an organic silicon photothermal anti-icing coating with in situ Co-MOF modified surface.
[0034] Example 3
[0035] The preparation method of the organosilicon photothermal anti-icing coating with in-situ Fe-MOF modification on the surface is carried out according to the following steps:
[0036] 1) Dissolve 3 parts of cobalt nitrate hexahydrate in 50 parts of tetrahydrofuran, then add 80 parts of organosilicon emulsion and stir at room temperature for 2 hours. This yields a coating with a viscosity of 0.1-0.5 Pa·s. This coating is sprayed onto an aluminum sheet and cured for 24 hours to yield an unmodified organosilicon coating.
[0037] 2) dissolving 3 parts of benzimidazole imidazole in 20 parts of ethanol to obtain a modified solution, spraying the modified solution onto the surface of the organosilicon coating, and drying at room temperature to obtain an organosilicon photothermal anti-icing coating with in situ Fe-MOF modified surface.
[0038] Example 4
[0039] The preparation method of the organosilicon photothermal anti-icing coating with in-situ Fe-MOF modification on the surface is carried out according to the following steps:
[0040] 1) Dissolve 3 parts of cobalt nitrate hexahydrate in 50 parts of tetrahydrofuran, then add 80 parts of organosilicon emulsion and stir at room temperature for 2 hours. This yields a coating with a viscosity of 0.1-0.5 Pa·s. This coating is sprayed onto an aluminum sheet and cured for 24 hours to yield an unmodified organosilicon coating.
[0041] 2) Dissolving 3 parts of trimesic acid in 20 parts of ethanol to obtain a modified solution, spraying the modified solution onto the surface of the organosilicon coating, and drying at room temperature to obtain an organosilicon photothermal anti-icing coating with in situ Fe-MOF modified surface.
[0042] Example 5
[0043] The preparation method of the organic silicon photothermal anti-icing coating with in-situ Cu-MOF modification on the surface is carried out according to the following steps:
[0044] 1) Dissolve 3 parts of copper nitrate trihydrate in 50 parts of tetrahydrofuran, then add 80 parts of organosilicon emulsion and stir at room temperature for 2 hours. This gives a coating with a viscosity of 0.1-0.5 Pa·s. This coating is sprayed onto an aluminum sheet and cured for 24 hours to yield an unmodified organosilicon coating.
[0045] 2) Dissolving 3 parts of trimesic acid in 20 parts of ethanol to obtain a modified solution, spraying the modified solution onto the surface of the organosilicon coating, and drying at room temperature to obtain an organosilicon photothermal anti-icing coating with in situ Fe-MOF modified surface.
[0046] Comparative Example 1
[0047] The preparation method of the organosilicon anti-icing coating is carried out according to the following steps:
[0048] 1) Disperse 60 parts of Dow Corning Sylgard 184 PDMS in 50 parts of tetrahydrofuran and stir for 1 hour. Then, add 6 parts of the matching curing agent and stir for another 0.5 hour. The resulting coating has a viscosity of 0.1-0.5 Pa·s. This coating is sprayed onto an aluminum sheet and cured for 24 hours to obtain an unmodified silicone coating.
[0049] Performance testing:
[0050] 1) Surface morphology and structure
[0051] The surface morphologies of the samples of different embodiments and comparative examples were observed using a laser confocal microscope.
[0052] Figure 1 The surface morphology of the unmodified organosilicon coating in Comparative Example 1 is shown. The surface of the unmodified organosilicon coating is relatively smooth.
[0053] Figure 2 The surface morphology of the organosilicon photothermal anti-icing coating with in situ Co-MOF modification in Example 1 is shown. Compared with Comparative Example 1, obvious MOF nanoparticles appear on the surface of the coating in Example 1. These particles will improve the anti-icing performance of the coating and give the coating surface active photothermal deicing performance.
[0054] Figure 3 The surface morphology of the organosilicon photothermal anti-icing coating with in situ Co-MOF modification in Example 2 is shown. Compared with Comparative Example 1 and Example 1, the MOF particles on the surface of the coating of Example 2 have a larger particle size and a more uniform distribution, which further improves the photothermal performance and anti-icing performance of the coating.
[0055] Figure 4 The infrared spectra of the different coatings in Example 2 and Comparative Example 1 are shown. The results show that at 1500 cm -1 A large number of organic peaks were formed nearby, which was attributed to the formation of Co-MOF by benzimidazole combined with cobalt ions, proving that the Co-MOF successfully modified the organosilicon coating.
[0056] Figure 5The surface X-ray diffraction patterns of the different coatings in Example 2 and Comparative Example 1 are shown, and the results show that there is an obvious crystallization peak near 9°, which indicates the formation of Co-MOF crystals, proving that the Co-MOF successfully modified the silicone coating.
[0057] 2) Photothermal performance and anti-icing performance
[0058] In January in Qingdao, at 10:00 AM, with a temperature of around -5°C, different examples and comparative examples were placed outdoors, and the surface photothermal temperatures of the coatings were measured using temperature sensors. The results are shown in Table 1. Comparative Example 1, an organosilicon coating without MOF modification, had a surface temperature of only -3°C, failing to achieve thermal deicing. Examples 3 and 4 were MOF-modified organosilicon photothermal anti-icing coatings formed by combining trimesic acid with iron and copper ions. Their surface temperatures reached approximately 4°C and 3°C, respectively, meeting basic anti-icing requirements. Notably, the Co-MOF-modified organosilicon anti-icing coatings in Examples 1 and 2, formed by combining cobalt ions with 2-methylimidazole and benzimidazole, respectively, achieved surface temperatures of 10°C and 12°C, respectively. This is likely due to the excellent light absorption and photothermal conversion efficiency of the imidazole compounds. The in-situ MOF-modified organosilicon coatings exhibited excellent photothermal deicing effectiveness under winter sunlight.
[0059] Table 1
[0060] Comparison Item Photothermal temperature contact angle Delayed freezing time Ice adhesion strength Example 1 10±2℃ 115.3±0.5° 232±11s 43±2kPa Example 2 12±2℃ 117.5±0.6° 263±9s 38±2kPa Example 3 4±2℃ 113.2±0.3° 233±9s 42±3kPa Example 4 3±2℃ 114.4±0.4° 231±10s 41±3kPa Comparative Example 1 -3±1℃ 90.3±0.2° 120±13s 97±4kPa
[0061] 3) Contact angle performance
[0062] The surface contact angles of various examples and comparative examples were measured using a contact angle meter. The results are shown in Table 1. The water contact angle of the silicone coating without MOF modification (Comparative Example 1) was only 90.3°. After MOF modification, the surface contact angle increased. This is attributed to the formation of MOF nanoparticles, which increased the surface roughness and, consequently, the water contact angle. The water contact angles of Examples 1-4 were 115.3°, 117.5°, 113.2°, and 114.4°, respectively.
[0063] 4) Delayed freezing time
[0064] The coating was placed on a cold table at -15°C, with an ambient temperature of 10±2°C and a humidity of 20RH. A 10uL water droplet was dropped on the coating surface, and the temperature change of the droplet was recorded with a temperature sensor. The starting time point was the temperature below 0°C, and the ending time point was the formation of an obvious ice droplet tip. The delayed freezing time of different coatings was tested, and the results are shown in Table 1. The delayed freezing time of the silicone coating that has not been modified by MOF (Comparative Example 1) is only 120s. The surface delayed freezing time of the silicone anti-icing coating modified with different MOFs is improved. This is attributed to the fact that MOF nanoparticles increase the surface roughness and promote the formation of the Cassie-Baxter wetting state, thereby reducing the heat transfer process at the solid-liquid interface and increasing the delayed freezing time.
[0065] 5) Ice adhesion strength
[0066] The coating was placed in a -20°C refrigerator for pre-cooling for 0.5h, and then the mold was placed on the coating surface. Supercooled water was injected into the mold. After standing for 12 hours to freeze, the force used to push the ice on the surface was recorded with a thrust meter, and the ice adhesion strength was calculated based on the area. The results are shown in Table 1. The ice adhesion strength of the organosilicon coating without MOF modification (Comparative Example 1) was 97kPa. The surface ice adhesion strength of the organosilicon anti-icing coating after modification with different MOFs decreased significantly. The ice adhesion strengths of Examples 1-4 were 43, 38, 42, and 41kPa, respectively. The significant reduction in surface adhesion strength is attributed to the increase in surface roughness of the coating. The nanoparticles on the surface of the coating provide stress support for the propagation of interfacial cracks, thereby reducing the surface ice adhesion strength.
[0067] In summary, the organosilicon photothermal anti-icing coating with in-situ MOF modified surface prepared by the present invention has excellent anti-icing effect.
[0068] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the scope of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for preparing an organosilicon photothermal anti-icing coating with in-situ MOF modification on the surface is characterized by: The following steps are involved: Step S1, dissolving the hydrate of the metal salt in a diluent, then adding the organosiloxane, stirring the obtained coating, spraying the coating on the surface of the substrate, and drying to obtain an unmodified organosilicon coating. Step S2: dissolving the modifier in a solvent to form a modified solution, immersing the dried organic silicon coating in the modified solution, or spraying the modified solution on the surface of the coating, and drying at room temperature to obtain a MOF-modified organic silicon photothermal anti-icing coating.
2. The method for preparing a surface in-situ MOF-modified organosilicon photothermal anti-icing coating according to claim 1, characterized in that: The hydrate of the metal salt described in step S1 is one or more of ferric nitrate nonahydrate, ferric chloride hexahydrate, cobalt nitrate hexahydrate, cobalt chloride hexahydrate, nickel nitrate hexahydrate, nickel chloride hexahydrate, copper nitrate trihydrate, copper chloride dihydrate, zinc nitrate hexahydrate, zinc chloride and hydrates thereof.
3. The method for preparing a surface in-situ MOF-modified organosilicon photothermal anti-icing coating according to claim 1, characterized in that: The diluent described in step S1 is one or more of tetrahydrofuran, toluene, xylene, ethyl acetate, and butyl acetate.
4. The method for preparing a surface in-situ MOF-modified organosilicon photothermal anti-icing coating according to claim 1, characterized in that: The organic siloxane raw material described in step S1 is one of Dow Corning sylgard 184 PDMS and the organic silicone emulsion of Zhejiang Lingzhi New Materials Co., Ltd.
5. The method for preparing a surface in-situ MOF-modified organosilicon photothermal anti-icing coating according to claim 1, characterized in that: The modifier described in step S2 is one of trimesic acid, terephthalic acid, 2-methylimidazole, benzimidazole, and 2-aminoimidazole.
6. The method for preparing a surface in-situ MOF-modified organosilicon photothermal anti-icing coating according to claim 1, characterized in that: The solvent described in step S2 is one of ethanol, ethyl acetate and butyl acetate.
7. The surface in-situ MOF-modified organosilicon photothermal anti-icing coating prepared by the method according to any one of claims 1 to 6, characterized in that: The modifier in the modified solution reacts with the metal ions on the surface of the silicone to form MOF nanoparticles in situ, improving the surface hydrophobicity and photothermal properties and enhancing the anti-icing ability of the silicone coating.