A transparent patterned self-healing and self-cleaning coating and its preparation method

Abstract

This invention belongs to the field of functional coating preparation / construction technology, specifically relating to a transparent patterned self-healing and self-cleaning coating and its preparation method. The invention first uses functionalized trimethylsiloxane to obtain cage-like silsesquioxane via hydrolysis and condensation, then generates hydroxyl-functionalized cage-like silsesquioxane through a mercapto-olefin click chemistry reaction. Next, a polyurethane prepolymer is prepared through a polymerization addition reaction of hydroxyl-functionalized polydimethylsiloxane, isophorone diisocyanate, and an initiator. Then, the hydroxyl-functionalized cage-like silsesquioxane reacts with the polyurethane prepolymer to form an inorganic-organic hybrid polyurethane polymer. The polymer is then formulated into a coating, drop-coated onto the sample surface, and cured at room temperature to obtain a transparent patterned self-healing and self-cleaning coating. The coating constructed by this invention achieves long-lasting interface self-cleaning and anti-fouling properties through an organic solvent-assisted self-healing strategy, maintains clear optical transparency, and can achieve self-repair of mechanical damage to optical glass devices, showing broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of functional coating preparation / construction technology, specifically relating to a transparent patterned self-healing and self-cleaning coating and its preparation method. Background Technology

[0002] Currently, optical display device interfaces frequently suffer from weakened optical performance and reduced service life due to mechanical abrasion / scratching during service. For example, smartphone screens using traditional inorganic and organic glass substrates, as well as special optical lenses and optical mirrors, experience reduced light transmittance and failure of surface protection functions if mechanically damaged during use, leading to a shortened service life. Furthermore, repairing these devices presents significant scientific challenges, including complex fabrication processes and high technical bottlenecks. Therefore, given the harmfulness and difficulty in repairing mechanical damage to optical display device surfaces, developing transparent, self-healing, and long-lasting engineering serviceability (strong interfacial adhesion, surface anti-fouling properties, etc.) surface protection technologies has important scientific significance and potential application value.

[0003] Polymer coating technology, through flexible molecular design, can endow materials with special functions and convenient construction, making it one of the effective technologies for achieving high optical transparency, multiple self-healing properties, and surface anti-fouling properties. Currently, to ensure that optically transparent coatings are not affected by friction, wear, or impact damage during use, and that their optical transparency and service performance are not compromised, a common strategy is to utilize self-healing properties in conjunction with special functional materials to achieve excellent optical transparency and long-lasting self-cleaning performance. However, current self-healing polymers face the technical bottleneck of weakened engineering performance (interfacial adhesion, surface anti-fouling, etc.) after multiple self-healing processes, which limits their practical application in surface anti-fouling of optical lenses, touch screens, and transparent optical devices. For example, Chinese invention patent CN115262231A proposes the preparation of a superhydrophobic self-cleaning composite fabric coating by blending comb-shaped hydrophobic self-healing polyurethane with garnet-shaped magnetic silica nanospheres modified graphene. Although this superhydrophobic coating has excellent self-cleaning properties, it cannot guarantee that it will maintain extremely low contact angle hysteresis (self-cleaning properties) after mechanical damage and multiple self-healing processes. Patent CN115874441A uses inorganic / organic composite microspheres, nano-titanium dioxide, and hydrophobic polyurethane acrylate resin to prepare a superhydrophobic coating with self-cleaning and self-healing capabilities. However, this method not only requires the blending and compounding of multiple raw materials, resulting in complex preparation and difficulties in proportioning and application, but also faces the challenge of maintaining a low solid-liquid contact area after multiple self-healing processes, making it difficult to guarantee long-term self-cleaning properties under engineering service conditions. Therefore, it is necessary to develop new self-healing and self-cleaning antifouling coating technologies that possess multiple self-healing properties, long-term antifouling effect, strong interfacial adhesion, and high transparency. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention proposes a simple, low-cost, and highly transparent method for preparing a patterned self-healing and self-cleaning polymer coating. This method can achieve long-term self-cleaning and anti-fouling of the interface, maintain clear optical transparency, and enable self-repair of mechanical damage to optical glass devices, thus having broad application prospects.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention discloses a method for preparing a transparent patterned self-healing and self-cleaning coating, the method comprising the following steps:

[0007] S1. Dissolve 3-mercaptopropyltrimethoxysilane in a methanol-hydrochloric acid mixed solvent, and then dehydrate and condense it to obtain cage-like silsesquioxane (POSS-SH8);

[0008] S2. Cage-like silsesquioxane crystals, diethylene glycol monovinyl ether, and photoinitiator 2,2-dimethoxy-2-phenylacetophenone were dissolved in tetrahydrofuran solvent. After degassing by nitrogen bubbling, hydroxyl-functionalized cage-like silsesquioxane (POSS-OH8) was prepared by mercapto-olefin click reaction under ultraviolet light irradiation.

[0009] S3. Dissolve hydroxyl-functionalized polydimethylsiloxane and catalyst in an organic solvent, then add isophorone diisocyanate dropwise. After the addition, a polyurethane prepolymer (PDMS-PU) solution is obtained through a polymerization addition reaction.

[0010] S4. The hydroxyl-functionalized cage-like silsesquioxane of S2 is added to the polyurethane prepolymer solution of S3, and the inorganic-organic hybrid polyurethane polymer POSS-PPU is obtained by reaction.

[0011] S5. Dissolve POSS-PPU in a mixture of acetone and ethyl acetate to prepare a coating. Then, apply the resulting coating onto the sample surface and cure it at room temperature to obtain a transparent patterned self-healing and self-cleaning coating.

[0012] This invention first prepares cage-like silsesquioxane (POSS-SH8) via hydrolysis and condensation of functionalized trimethylsiloxane, then converts it into hydroxyl-functionalized cage-like silsesquioxane (POSS-OH8) through a mercapto-olefin click chemistry reaction. Next, a polyurethane prepolymer (PDMS-PU) solution is prepared through a polymerization addition reaction of hydroxyl-functionalized polydimethylsiloxane, isophorone diisocyanate, and an initiator. POSS-OH8 is then reacted with PDMS-PU to form an inorganic-organic hybrid polyurethane polymer (POSS-PPU). The POSS-PPU is then formulated into a coating, drop-coated onto the sample surface, and cured at room temperature to obtain a transparent, patterned, self-healing, and self-cleaning coating. This invention offers a simple and low-cost method, and the resulting coating provides long-lasting self-cleaning and anti-fouling properties at the interface, maintains clear optical transparency, and enables self-repair of mechanical damage to optical glass devices, demonstrating broad application prospects.

[0013] Preferably, the dehydration condensation reaction in S1 is carried out at a temperature of 80-100°C for 40-60 hours.

[0014] Preferably, the volume ratio of methanol to hydrochloric acid in S1 is 10-15:1, and the volume ratio of 3-mercaptopropyltrimethoxysilane to the methanol-hydrochloric acid mixed solvent is 1:2-3.

[0015] Preferably, in S2, the diethylene glycol monovinyl ether is selected from ethylene glycol vinyl ether, the molar ratio of the cage-like silsesquioxane to the diethylene glycol monovinyl ether is 1:8-8.5, and the mass fraction of the photoinitiator is 1-2% of the mass of the cage-like silsesquioxane.

[0016] Preferably, in S2, the reaction temperature is room temperature and the time is 0.5-1.5 hours; the wavelength of the ultraviolet lamp irradiation is 365nm and the power is 40-60W.

[0017] Preferably, in S3, the catalyst is selected from dibutyltin dilaurate (DBTDL), the molar ratio of the hydroxyl-functionalized polydimethylsiloxane to isophorone diisocyanate is 1:2.2-3, and the mass fraction of the catalyst is 0.5-1.5% of the mass of the hydroxyl-functionalized polydimethylsiloxane.

[0018] Preferably, the polymerization addition reaction in S3 is carried out at a temperature of 65-80°C for 2-12 hours.

[0019] Preferably, the organic solvent in S3 is selected from chromatographically pure methanol, dimethylacetamide, acetone, tetrahydrofuran, or ethyl acetate.

[0020] Preferably, in S4, the mass fraction of the hydroxyl-functionalized cage-like silsesquioxane is 5-10% of the polyurethane prepolymer solution; the reaction temperature is 40-60°C, and the reaction time is 1-8 hours.

[0021] The present invention also discloses a transparent patterned self-healing and self-cleaning coating prepared by the above preparation method.

[0022] The coating obtained by this invention achieves a light transmittance of 81.3% (wavelength 550nm), WCA = 95°, CAH = 18°, and interfacial adhesion strengths of approximately 2.37 MPa and 12.01 MPa on inorganic bare glass substrates and organic polycarbonate substrates, respectively. Simulated motion tests with contaminating media such as acids, alkalis, salts, inks, orange juice, and milk beverages have demonstrated its excellent self-cleaning and anti-fouling properties. After mechanical damage to the coating surface, it can self-repair using solvents such as ethanol and ethyl acetate, while still maintaining excellent optical transparency and anti-fouling performance.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] This invention discloses a method for preparing a transparent patterned self-healing and self-cleaning coating. First, a cage-like silsesquioxane (POSS-SH8) is prepared using a functionalized trimethylsiloxane via hydrolysis-condensation. Then, a hydroxyl-functionalized cage-like silsesquioxane (POSS-OH8) is rapidly prepared using a mercapto-olefin click chemistry reaction. Simultaneously, a polyurethane prepolymer (PDMS-PU) solution is prepared by polymerization addition reaction of hydroxyl-functionalized polydimethylsiloxane, isophorone diisocyanate, and a small amount of initiator under nitrogen protection and heating conditions. The POSS-OH8 solution is then reacted with the PDMS-PU solution to obtain an inorganic-organic hybrid polyurethane polymer (POSS-PPU). Finally, the POSS-PPU is formulated into a coating and drop-coated onto the sample surface. Curing at room temperature yields the transparent patterned self-healing and self-cleaning coating. This invention utilizes POSS-PPU and employs a traditional drop-coating process combined with room-temperature curing to construct a patterned self-healing polymer coating that possesses reliable interface self-cleaning and antifouling properties. Simultaneously, an organic solvent-assisted self-healing strategy can achieve long-lasting interface self-cleaning and anti-fouling properties, maintain clear optical transparency, and enable self-repair of mechanical damage to optical glass devices. This invention has the following advantages:

[0025] (1) After the coating of the present invention is applied by drop, the sample can be cured at room temperature to form a film;

[0026] (2) The sample after being coated with the coating of the present invention has good adhesion to the surface of the engineering material;

[0027] (3) The sample after being coated with the coating of the present invention has the properties of self-cleaning and anti-fouling on the surface and the function of inhibiting fingerprint stains of ink pad, which can reduce the spreading area of ​​ink pad fingerprint droplets on the surface.

[0028] (4) The ordered array patterned surface constructed by the present invention can maintain long-term self-cleaning and anti-fouling properties through a multi-solvent-assisted self-healing strategy;

[0029] (5) The ordered array patterned surface constructed by the present invention can still maintain high optical transparency after multiple solvent wetting treatment. Attached Figure Description

[0030] Figure 1 The images are SEM images of the coating surface, including: water contact angle (a), SEM image of the self-healing process of the scratched surface (b), optical transparency and large-scale preparation of bare glass and polymer coating (c), movement of red ink and milk beverage contaminant on the tilted coating surface (d), fingerprint contamination behavior on bare glass and polymer coating surface (e), and engineering application of the mechanical properties of polymer coating (f).

[0031] Figure 2 SEM images of the surface after ethanol-assisted self-healing include: water contact angle (a), optical microscope image of ethanol-assisted scratch self-healing surface; macroscopic digital photograph of scratch self-healing (b), image of orange juice contaminant movement on the ethanol-assisted self-healing coating surface (c), and image of the mechanical properties and engineering applications of the ethanol-assisted self-healing coating (d).

[0032] Figure 3 The images show SEM images of the surface after ethyl acetate-assisted self-healing, including: water contact angle (a), optical microscope image of ethyl acetate-assisted scratch self-healing surface, macroscopic digital photograph of scratch self-healing (b), image of orange juice contaminant movement on the ethyl acetate-assisted self-healing coating surface (c), and engineering application image of the mechanical properties of the ethyl acetate-assisted self-healing coating (d). Detailed Implementation

[0033] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0035] Example 1: A transparent patterned self-healing and self-cleaning coating and its preparation method

[0036] (1) Mix 10 mL of 3-mercaptopropyltrimethoxysilane, 20 mL of 36% hydrochloric acid and 240 mL of methanol in a three-necked flask (equipped with magnetic stirring and reflux condensation), and allow the system to hydrolyze and condense at 90 °C for 48 hours to obtain cage-like silsesquioxane (POSS-SH8).

[0037] (2) 1.00 g of POSS-SH (1.00 mmol), 0.75 g of ethylene glycol ether (8.5 mmol, CAS No.: 764-48-7) and 50 mg of photocatalyst 2,2-dimethoxy-2-phenylacetophenone (0.2 mmol) were dissolved in 15 mL of anhydrous tetrahydrofuran. After degassing with nitrogen for 20 min, the solution was irradiated with a UV lamp (365 nm, 48 W) at room temperature for 1.5 h to obtain hydroxyl-functionalized cage-like silsesquioxane (POSS-OH8).

[0038] (3) 1.00 g of hydroxyl-functionalized polydimethylsiloxane (CAS: 156327-07-0) (1.00 mmol) and 2 drops of catalyst dibutyltin dilaurate (DBTDL) were dissolved in 10 mL of dimethylacetamide (DMAC). Then, 0.62 g of isophorone diisocyanate (2.8 mmol) dissolved in 15 mL of DMAC was added dropwise through a constant pressure dropping funnel under a nitrogen atmosphere. After the addition was completed, the system was heated to 80 °C and reacted for 2 hours to obtain a polyurethane prepolymer solution (PDMS-PU).

[0039] (4) Dissolve 0.28 g of POSS-OH in 15 mL of DMAC, and then add it to the three-necked flask containing the prepolymer from step (3) using a syringe. After reacting at 60 °C for 1 hour, the inorganic-organic hybrid polyurethane polymer POSS-PPU is obtained. Finally, remove the DMAC using a rotary evaporator, and dissolve the transparent, viscous POSS-PPU in a 1:1 mixture of acetone and ethyl acetate (concentration approximately 200 g / L) to prepare a coating.

[0040] (5) The mixed coating obtained in step (4) is drop-coated onto a glass substrate and cured at room temperature to obtain a transparent patterned self-healing and self-cleaning polymer coating. The coating surface has an ordered array of micro-nano textured patterns. Figure 1 a) The water static contact angle (WCA) is 92-97°, and the contact angle hysteresis (CAH) is 17-20°, exhibiting significant self-cleaning, non-stick, and hydrophobic surface properties. After scratches / damage to the coating surface, the damaged area can self-repair under ethanol solvent-assisted conditions. Figure 1(b) It possesses rapid self-healing properties. Large-scale fabrication of the coating on bare glass surfaces revealed excellent optical transparency, making it suitable for use in mobile phone screens, etc., while maintaining original optical characteristics. Quantitative characterization using UV-Vis testing showed its transmittance at 550nm wavelength to be approximately 81.3%. Figure 1 c). Evaluation of adhesion / pinning / slippage behavior of self-cleaning coated surfaces tilted at 15-20° under different soiling media (acids, alkalis, salts, inks, orange juice, and milk drinks, etc.). Figure 1 d) It was observed that under different acid and alkaline media, both inorganic and protein contaminants could slide / remove from the anti-fouling surface, reaching a sliding rate of 2-5 mm / s within 20-30 seconds, with no obvious contaminant residue visible on the surface. Fingerprint contamination tests, observed under an optical microscope, showed that the film formed on the glass substrate inhibited the spread of fingerprint droplets. The coverage rate of fingerprint droplets on the uncoated bare glass surface was 45-55%, while the coverage rate on the coated surface was only 10-15%. Figure 1 e). The adhesion strength of the coating on transparent bare glass substrate and polycarbonate substrate is 2.37 MPa and 12.01 MPa, respectively. Using POSS-PPU polymer as an adhesive to form an overlapping structure with two bare glass substrates, it can withstand a weight of 3 kg. Figure 1 f) demonstrates that the coating possesses robust interfacial adhesion properties.

[0041] Example 2: A transparent patterned self-healing and self-cleaning coating and its preparation method

[0042] (1) Mix 10 mL of 3-mercaptopropyltrimethoxysilane, 20 mL of 36% hydrochloric acid and 240 mL of methanol in a three-necked flask (equipped with magnetic stirring and reflux condensation), and allow the system to hydrolyze and condense at 90 °C for 48 hours to obtain cage-like silsesquioxane (POSS-SH8).

[0043] (2) Dissolve 1.00 g of POSS-SH (1.00 mmol), 0.72 g of ethylene glycol ether (8.2 mmol) and 50 mg of photocatalyst 2,2-dimethoxy-2-phenylacetophenone (0.2 mmol) in 15 mL of anhydrous tetrahydrofuran. After degassing with nitrogen for 20 min, irradiate with a UV lamp (365 nm, 48 W) at room temperature for 1 hour to obtain hydroxyl-functionalized cage-like silsesquioxane (POSS-OH8).

[0044] (3) 1.00 g of hydroxyl-functionalized polydimethylsiloxane (CAS: 156327-07-0) (1.00 mmol) and 2 drops of catalyst DBTDL were dissolved in 10 mL of DMAC. Then, 0.48 g of isophorone diisocyanate (2.2 mmol) dissolved in 5 mL of DMAC was added dropwise through a constant pressure dropping funnel under a nitrogen atmosphere. After the addition was completed, the system was heated to 65 °C and reacted for 12 hours to obtain a polyurethane prepolymer solution (PDMS-PU).

[0045] (4) Dissolve 0.14 g of POSS-OH in 5 mL of DMAC, and then add it to the three-necked flask containing the prepolymer from step (3) using a syringe. After reacting at 40 °C for 8 hours, the inorganic-organic hybrid polyurethane polymer POSS-PPU is obtained. Finally, remove the DMAC using a rotary evaporator, and dissolve the transparent, viscous POSS-PPU in a 1:1 mixture of acetone and ethyl acetate (concentration approximately 200 g / L) to prepare a coating.

[0046] (5) The mixed coating obtained in step (4) is drop-coated onto a glass substrate and cured at room temperature to obtain a transparent patterned self-healing and self-cleaning polymer coating. After self-healing with the aid of ethanol solvent, the surface of the coating exhibits a micro-nano scale wrinkled structure. Figure 2 a) The static water contact angle is 91-95°, and the contact angle hysteresis is 18-22°, exhibiting significant self-cleaning, anti-sticking, and hydrophobic surface properties. Optical microscopy observations showed that surface scratches disappeared / restored. After scratches / abrasions, the surface optical properties were restored through a synergistic ethanol solvent-assisted repair strategy. The original coating had a transmittance of 81.3% at 550nm, while the transmittance after ethanol organic solvent-assisted self-repair was 81.2%, demonstrating rapid self-repair characteristics. Figure 2 b). Simultaneously, the movement of the contaminated droplets was observed to evaluate the coating's self-cleaning and anti-fouling performance; the results are as follows: Figure 2 As shown in Figure c, the coating repaired with ethanol organic solvent multiple times can achieve the sliding / removal of orange juice stains on the surface. During the period t = 0-30s, the contaminated droplets moved approximately 60mm at an average speed of 2-2.5mm / s, and no obvious contamination residue was observed on the surface. This indicates that the coating still retains hydrophobic and self-cleaning anti-fouling surface properties after multiple ethanol-assisted self-repairs. Pull-out tests show that the interfacial adhesion strength of the ethanol-repaired coating is approximately 1.89MPa. After desorption of the bare glass substrate using ethanol solvent, reversible adhesion can be achieved by treating it at 80℃ for 10-30 minutes. Overlap tests prove that it can withstand the weight of a 2kg weight. Figure 2 d) demonstrates that the coating has strong interfacial adhesion properties.

[0047] Example 3: A transparent patterned self-healing and self-cleaning coating and its preparation method

[0048] (1) Mix 10 mL of 3-mercaptopropyltrimethoxysilane, 20 mL of 36% hydrochloric acid and 240 mL of methanol in a three-necked flask (equipped with magnetic stirring and reflux condensation), and allow the system to hydrolyze and condense at 90 °C for 48 hours to obtain cage-like silsesquioxane (POSS-SH8).

[0049] (2) Dissolve 1.00 g of POSS-SH (1.00 mmol), 0.71 g of ethylene glycol ether (8 mmol) and 50 mg of photocatalyst 2,2-dimethoxy-2-phenylacetophenone (0.2 mmol) in 15 mL of anhydrous tetrahydrofuran. After degassing with nitrogen for 20 min, irradiate with a UV lamp (365 nm, 48 W) at room temperature for 1 hour to obtain hydroxyl-functionalized cage-like silsesquioxane (POSS-OH8).

[0050] (3) 1.00 g of hydroxyl-functionalized polydimethylsiloxane (CAS: 156327-07-0) (1.00 mmol) and 2 drops of catalyst DBTDL were dissolved in 10 mL of dimethylacetamide. Then, 0.56 g of isophorone diisocyanate (2.5 mmol) dissolved in 10 mL of DMAC was added dropwise through a constant pressure dropping funnel under a nitrogen atmosphere. The system was heated to 70 °C and reacted for 8 hours to obtain a polyurethane prepolymer solution (PDMS-PU).

[0051] (4) Dissolve 0.19 g of POSS-OH in 10 mL of DMAC, and then add it to the three-necked flask containing the prepolymer from step (3) using a syringe. After reacting at 50 °C for 3 hours, the inorganic-organic hybrid polyurethane polymer POSS-PPU is obtained. Finally, remove the DMAC using a rotary evaporator, and dissolve the transparent and viscous POSS-PPU in a mixed solvent of acetone / ethyl acetate at a volume ratio of 1:1 (concentration of approximately 200 g / L) to prepare a coating.

[0052] (5) The mixed coating obtained in step (4) is drop-coated onto a glass substrate and cured at room temperature to obtain a transparent patterned self-healing and self-cleaning polymer coating. After self-healing with the assistance of ethyl acetate solvent, the surface of the coating exhibits a micro-nano porous structure. Figure 3 a) The static water contact angle is 80-90°, and the contact angle hysteresis is 30-40°. The disappearance / recovery of surface scratches was observed using an optical microscope. After scratches / abrasions, the surface optical properties can be restored through a synergistic repair strategy using ethyl acetate solvent. After self-repair with ethyl acetate organic solvent assistance, the surface transmittance is 73.1%, demonstrating rapid self-repair characteristics. Figure 3 b). Observe the movement of contaminated droplets to evaluate the self-cleaning and antifouling performance of the coating. The results are as follows: Figure 3As shown in Figure c, the coating repaired with ethyl acetate organic solvent multiple times can achieve the sliding of orange juice stains on the surface. Between t = 50-60 s, the stain droplets moved approximately 60 mm, with a sliding speed of about 1.0-1.5 mm / s. Only a small amount of residual stain residue was observed on the EA-SHS surface. Pull-out tests showed that the adhesion strength of the ethyl acetate-repaired coating interface was approximately 1.23 MPa. After desorption of the bare glass substrate using ethyl acetate solvent, reversible adhesion could be achieved by further treatment at 60℃ for 5-15 minutes. Overlap tests demonstrated that it could withstand the weight of a 1 kg weight. Figure 3 d) proves that the coating has strong adhesion properties.

[0053] In summary, the coating prepared using the method of this invention is a transparent patterned coating with an ordered array, possessing reliable interface self-cleaning and anti-fouling properties. Furthermore, the organic solvent-assisted self-healing strategy enables long-lasting interface self-cleaning and anti-fouling properties while maintaining clear optical transparency, allowing for self-repair of mechanical damage to optical glass devices and demonstrating broad application prospects.

[0054] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for preparing a transparent patterned self-healing and self-cleaning coating, characterized in that, Includes the following steps: S1. 3-Mercaptopropyltrimethoxysilane was dissolved in a methanol-hydrochloric acid mixed solvent and then dehydrated and condensed to obtain a cage-like silsesquioxane. S2. Cage-like silsesquioxane crystals, ethylene glycol vinyl ether, and photoinitiator 2,2-dimethoxy-2-phenylacetophenone were dissolved in tetrahydrofuran solvent. After degassing under nitrogen bubbling, the hydroxyl-functionalized cage-like silsesquioxane was prepared by a mercapto-olefin click reaction under ultraviolet light irradiation. The molar ratio of cage-like silsesquioxane to ethylene glycol vinyl ether was 1:8-8.

5. S3. Dissolve hydroxyl-functionalized polydimethylsiloxane and catalyst in an organic solvent, then add isophorone diisocyanate dropwise. After the addition, a polyurethane prepolymer solution is obtained through a polymerization addition reaction. S4. The hydroxyl-functionalized cage-like silsesquioxane from S2 is added to the polyurethane prepolymer solution from S3, and the inorganic-organic hybrid polyurethane polymer POSS-PPU is prepared by reaction; the mass fraction of the hydroxyl-functionalized cage-like silsesquioxane is 5-10% of the polyurethane prepolymer solution; S5. Dissolve POSS-PPU in a mixture of acetone and ethyl acetate to prepare a coating. Then, apply the resulting coating onto the sample surface and cure it at room temperature to obtain a transparent patterned self-healing and self-cleaning coating.

2. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, The dehydration condensation reaction described in S1 is carried out at a temperature of 80-100℃ for 40-60 hours.

3. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, The volume ratio of methanol to hydrochloric acid in S1 is 10-15:1, and the volume ratio of 3-mercaptopropyltrimethoxysilane to the methanol-hydrochloric acid mixed solvent is 1:2-3.

4. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, In S2, the mass fraction of the photoinitiator is 1-2% of the mass of the cage-like silsesquioxane.

5. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, In S2, the reaction temperature is room temperature and the time is 0.5-1.5 hours; the wavelength of the ultraviolet lamp irradiation is 365nm and the power is 40-60W.

6. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, In S3, the catalyst is dibutyltin dilaurate, the molar ratio of the hydroxyl-functionalized polydimethylsiloxane to isophorone diisocyanate is 1:2.2-3, and the mass fraction of the catalyst is 0.5-1.5% of the mass of the hydroxyl-functionalized polydimethylsiloxane.

7. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, The polymerization addition reaction described in S3 is carried out at a temperature of 65-80℃ for 2-12 hours.

8. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, The organic solvent in S3 is selected from chromatographically pure methanol, dimethylacetamide, acetone, tetrahydrofuran, or ethyl acetate.

9. The method for preparing a transparent patterned self-healing and self-cleaning coating according to claim 1, characterized in that, In S4, the reaction temperature is 40-60℃ and the reaction time is 1-8 hours.

10. A transparent patterned self-healing and self-cleaning coating prepared by the preparation method according to any one of claims 1-9.

Images