Preparation method of an antifouling and antibacterial spectacle lens coating

Abstract

This application relates to the field of optical lens coatings, and specifically discloses a preparation method for an anti-fouling and antibacterial coating for spectacle lenses. The preparation method for the anti-fouling and antibacterial coating for spectacle lenses is as follows: deposit a silica substrate on the lens surface through plasma-enhanced chemical vapor deposition treatment; disperse nano-graphene and nano-silver particles in an ethanol solvent, then add a silane coupling agent to form a homogeneous suspension, and load the suspension on the surface of the silica substrate by spin coating, and cure it by heat treatment to form an antibacterial layer, wherein the nano-silver loading amount is ≤ 0.5 wt%; perform etching treatment on the surface of the antibacterial layer by reactive ion etching method, and then graft perfluorooctyltriethoxysilane on the etched surface at 80-100 °C by vapor deposition method to form a hydrophobic layer. The preparation method for the anti-fouling and antibacterial coating for spectacle lenses of this application has the advantages of antibacterial, anti-fouling and strong durability.

Description

Technical Field

[0001] This application relates to the field of optical lens coatings, and more specifically, it relates to a preparation method of an anti-fouling and antibacterial coating for spectacle lenses. Background Art

[0002] Modern spectacle lens coating technology covers multiple functional thin films on the lens surface through nanoscale processes, significantly enhancing the visual experience and lens durability. Common coating types include anti-reflection films (reducing reflective interference), anti-fouling and hydrophobic films (resisting fingerprints and oil stains), anti-blue light films (filtering harmful light), and anti-static films (reducing dust adsorption). These coatings not only optimize the light transmittance but also achieve comprehensive protection such as scratch resistance and ultraviolet protection through composite superposition, becoming an important barrier for spectacle wearers to confront daily environmental challenges.

[0003] Despite the continuous progress of coating technology, the persistence of its antibacterial and anti-fouling capabilities remains a pain point in the industry. During daily use, the lens surface is prone to residual sebum, sweat, and air pollutants. The hydrophobic effect of traditional anti-fouling films gradually decays with friction and cleaning, resulting in the adsorption of oil to form stubborn stains. More seriously, the coating layer lacks long-acting antibacterial components and is prone to bacterial growth in a humid environment, which may cause eye infections or skin sensitivity problems. Summary of the Invention

[0004] In order to enable the spectacle lens coating to maintain long-term antibacterial and anti-fouling performance, this application provides a preparation method of an anti-fouling and antibacterial coating for spectacle lenses.

[0005] The preparation method of an anti-fouling and antibacterial coating for spectacle lenses provided by this application adopts the following technical solutions:

[0006] A preparation method of an anti-fouling and antibacterial coating for spectacle lenses includes the following steps:

[0007] Deposit a silicon dioxide substrate with a thickness of 50 - 100 nm on the lens surface through plasma-enhanced chemical vapor deposition treatment;

[0008] Disperse nanographene and silver nanoparticles in an ethanol solvent at a mass ratio of (1 - 3):1, then add a silane coupling agent to form a homogeneous suspension, and load the suspension on the surface of the silicon dioxide substrate by spin coating, and cure it by heat treatment at 120 - 150 °C to form an antibacterial layer, where the silver nanoparticle loading is ≤ 0.5 wt%;

[0009] Perform etching treatment on the surface of the antibacterial layer by reactive ion etching, with an etching power of 80 - 120 W and an etching depth of 100 - 200 nm, and then graft perfluorooctyltriethoxysilane on the etched surface at 80 - 100 °C by chemical vapor deposition to form a hydrophobic layer.

[0010] By adopting the above technical solution, a dense silica substrate is formed by plasma-enhanced chemical vapor deposition (PECVD), providing excellent adhesion and optical transparency; nano-graphene and nano-silver particles are fixed by covalent bonds to form a synergistic antibacterial layer, and the nano-silver loading ≤ 0.5 wt% achieves efficient antibacterial while ensuring safety; reactive ion etching combined with fluorosilane modification constructs a biomimetic hydrophobic structure, significantly improving the anti-fouling ability and reducing fingerprint and grease adsorption. The overall process takes into account long-term antibacterial, self-cleaning and mechanical durability, meeting the daily use requirements.

[0011] Optionally, the radio frequency power supply frequency of the plasma-enhanced chemical vapor deposition treatment is 13.56 MHz, the power density is 0.5 - 1.5 W / cm², and the deposition rate is 5 - 10 nm / min.

[0012] By adopting the above technical solution, by defining the radio frequency power supply frequency, power density and deposition rate, the plasma energy distribution and reaction uniformity are optimized, ensuring uniform thickness of the silica substrate, significantly reducing the surface roughness, effectively avoiding substrate defects, enhancing the bonding strength between the coating and the lens body, and maintaining high light transmittance at the same time.

[0013] Optionally, the etching gas used in the reactive ion etching is a CF4 / O2 mixed gas, and the gas flow ratio of the reactive ion etching is CF4:O2 = (2 - 4):1.

[0014] By adopting the above technical solution, reactive ion etching is carried out using a CF4 / O2 mixed gas. The etching directionality is controlled synergistically by the chemical oxidation of O2 and the physical bombardment of CF4 to form a honeycomb-like micro-nano structure with steep sidewalls and uniform pore diameters on the surface of the antibacterial layer. Optimization of the CF4 / O2 ratio can balance the etching rate and structural fidelity, avoid the loss of antibacterial agents caused by over-etching, and provide an ideal morphology substrate for subsequent fluorosilane modification.

[0015] Optionally, an alternating magnetic field with an intensity of 0.1 - 0.5 T is applied to the etching area during the reactive ion etching process.

[0016] By adopting the above technical solution, the paramagnetism of nano-silver particles is utilized to induce their directional arrangement along the magnetic field direction to form a continuous conductive network. Magnetic field-assisted etching synchronously optimizes the anisotropic distribution of the honeycomb structure, enables the antibacterial agents to be enriched on the surface of the micro-columns / holes, increases the antibacterial active area, and the antistatic performance inhibits dust adsorption.

[0017] Optionally, after the etching treatment on the surface of the antibacterial layer, a secondary etching is required, and the power of the secondary etching is 20 - 40 W and the etching depth is 40 - 80 nm.

[0018] By adopting the above technical solution, a secondary nano-scale texture can be further constructed on the surface of the 100-200 nm main groove structure formed by one-time etching. Through the size gradient design of double etching, the surface roughness presents a multi-level nested feature, further increasing the water droplet contact angle and reducing the rolling angle. At the same time, the micro-nano structure formed by secondary etching can also increase the grafting surface area of the subsequent hydrophobic layer, enabling perfluorosilane molecules to form a denser low surface energy coverage layer on the surface, and enhancing the repelling ability of the coating to pollutants such as oils and dust.

[0019] Optionally, nitrogen-doped titanium dioxide with a particle size of 5-15 nm is further added to the suspension, and the addition amount of the nitrogen-doped titanium dioxide is 10-30% of the mass of the nano silver.

[0020] By adopting the above technical solution, after adding nitrogen-doped titanium dioxide, the antibacterial layer generates reactive oxygen under visible light excitation of 400-550 nm, and attacks the bacterial cell membrane synergistically with silver nano-ions, further enhancing the antibacterial and bacteriostatic effects.

[0021] Optionally, the preparation method of the nitrogen-doped titanium dioxide is as follows:

[0022] Mix tetrabutyl titanate and absolute ethanol at a volume ratio of 1:(3-5), and add citric acid. The molar ratio of citric acid to tetrabutyl titanate is 1:(10-20) to obtain solution A;

[0023] Dissolve urea in deionized water to prepare solution B with a concentration of 0.5-1.5 mol / L;

[0024] Dropwise add solution B into solution A. The volume ratio of solution A to solution B added is (5-3):1, and use microwave with a power of 300-500 W, a temperature of 80-100 °C, and a reaction time of 20-40 minutes to obtain a gel;

[0025] The gel is subjected to the following three-stage heat treatment in sequence:

[0026] The first stage: Keep warm in an air atmosphere at 200-250 °C for 1-1.2 hours;

[0027] The second stage: Keep warm in a nitrogen atmosphere at 350-400 °C for 2-2.2 hours;

[0028] The third stage: Anneal in an argon atmosphere at 500-550 °C and keep warm for 30-40 minutes;

[0029] Ball-mill and sieve the annealed product to obtain nitrogen-doped titanium dioxide with a particle size of 5-15 nm.

[0030] By adopting the above technical solution, nitrogen-doped TiO2 is prepared by using the microwave-assisted sol-gel method combined with a three-stage annealing process. The microwave field accelerates hydrolysis and in-situ doping of nitrogen atoms, and the decomposition of urea provides a uniform nitrogen source. The three-stage heat treatment can regulate the crystal phase and the amount of nitrogen doping, shift the optical absorption edge to 550 nm, significantly improve the visible light catalytic efficiency compared with the traditional method, and have excellent particle dispersibility.

[0031] Optionally, during the third-stage annealing process, hydrogen with a volume fraction of 5-10% is introduced into argon.

[0032] By adopting the above technical solution, 5-10% hydrogen is introduced during the third-stage annealing to form a weakly reducing atmosphere, inducing oxygen vacancy defects in the TiO2 lattice. Oxygen vacancies act as electron traps to inhibit the recombination of photo-generated carriers, increase the photocurrent density, and enhance the adsorption and activation ability of organic substances. Hydrogen-assisted annealing simultaneously inhibits excessive grain growth and ensures the compatibility of nanoparticles and the coating.

[0033] In summary, the present application has the following beneficial effects:

[0034] 1. Since the present application enhances the adhesion through a dense silica bottom layer, then realizes efficient and safe antibacterial by a graphene / silver synergistic antibacterial layer, constructs a micro-nano rough structure by reactive ion etching + grafts fluorosilane to form a low surface energy hydrophobic layer. With this multi-layer functional design, the coating has long-term antibacterial, superhydrophobic anti-fouling, high light transmittance and coating durability, meeting the long-term use requirements of spectacle lenses in daily complex environments.

[0035] 2. In the present application, preferably through the hierarchical rough structure design of "main grooves + secondary textures", a multi-level nested roughness gradient is formed on the coating surface, significantly improving the air trapping ability and the grafting efficiency of the hydrophobic layer molecules, achieving an increase in the contact angle and a decrease in the rolling angle.

[0036] 3. The method of the present application expands the optical absorption edge to 550 nm through nitrogen atom doping and oxygen vacancy defect regulation, improves the visible light catalytic efficiency, generates reactive oxygen species under light irradiation, and forms a dual antibacterial mechanism with nano silver ions. A weakly reducing atmosphere of 5-10% hydrogen is introduced in the third stage of heat treatment, further inhibiting the recombination of photo-generated carriers, and ensuring the uniform dispersion of nanoparticles in the coating, avoiding the decrease in light transmittance and functional attenuation caused by agglomeration. Specific Embodiments

[0037] The following further elaborates on the present application with reference to embodiments. It should be specifically noted that: for those not specifying specific conditions in the following embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Except for special instructions, the raw materials used in the following embodiments can all be obtained from ordinary commercial sources.

[0038] Preparation Example 1

[0039] A preparation method of nitrogen-doped titanium dioxide is as follows:

[0040] Prepare the following raw materials:

[0041] Tetrabutyl titanate (TBT, purity ≥ 99%), absolute ethanol (analytical pure), citric acid (analytical pure), urea (analytical pure), deionized water (resistivity ≥ 18 MΩ·cm), argon (purity ≥ 99%), nitrogen (purity ≥ 99%), hydrogen (purity ≥ 99%).

[0042] Measure 20 mL of tetrabutyl titanate, add 80 mL of absolute ethanol, and magnetically stir for 5 minutes until evenly mixed.

[0043] Weigh 0.88 g of citric acid, with a molar ratio of TBT:citric acid = 1:15, slowly add it to the above-mentioned mixed solution, and continue stirring for 30 minutes to form a transparent light yellow solution A.

[0044] Weigh 12.0 g of urea, dissolve it in 100 mL of deionized water to prepare solution B with a concentration of 1.0 mol / L, and ultrasonically treat it for 10 minutes until completely dissolved.

[0045] Add solution B dropwise to solution A at a rate of 2 mL / min, with a total volume ratio of solution A:solution B = 4:1, continuously magnetically stir to obtain a mixed solution. Transfer the mixed solution to a microwave reaction kettle, set the parameters: microwave power 400 W, temperature 90 °C, reaction time 30 minutes, and simultaneously apply ultrasonic assistance with a power density of 80 W / L. After the reaction, obtain a light blue translucent gel and let it stand and age for 12 hours.

[0046] First stage: Place the gel in an alumina crucible, put it into a tube furnace, and introduce air with a flow rate of 200 mL / min. Heat it to 220 °C at a rate of 5 °C / min and keep it warm for 1 hour to remove residual organic matter.

[0047] Second stage: Switch to a nitrogen atmosphere with a flow rate of 150 mL / min, heat it to 375 °C at a rate of 5 °C / min, and keep it warm for 2 hours to promote the substitution of nitrogen atoms for lattice oxygen.

[0048] Third stage: Switch to a mixed gas of argon - hydrogen, with argon:hydrogen = 92.5:7.5 (volume fraction), and a flow rate of 100 mL / min. Heat it to 525 °C at a rate of 10 °C / min, keep it warm for 35 minutes, and then naturally cool to room temperature.

[0049] Crush the heat-treated bulk material, put it into a ball mill jar with zirconia grinding balls according to a ball-to-material ratio of 10:1, set the rotation speed to 300 rpm, and the time to 3 hours. Pause for 10 minutes every 30 minutes to prevent overheating. Screen the ball-milled product through a 400-mesh sieve to collect N-TiO2 nanoparticles with a particle size of 5 - 15 nm.

[0050] Preparation Example 2

[0051] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that the molar ratio of citric acid to tetrabutyl titanate is 1:10.

[0052] Preparation Example 3

[0053] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that the molar ratio of citric acid to tetrabutyl titanate is 1:20.

[0054] Preparation Example 4

[0055] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that the concentration of Solution B is 0.5 mol / L.

[0056] Preparation Example 5

[0057] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that the concentration of Solution B is 1.5 mol / L.

[0058] Preparation Example 6

[0059] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that the volume ratio of Solution A to Solution B added is 5:1.

[0060] Preparation Example 7

[0061] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that the volume ratio of Solution A to Solution B added is 3:1.

[0062] Preparation Example 8

[0063] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that hydrogen is not introduced into argon during the annealing process in the third stage.

[0064] Preparation Example 9

[0065] A method for preparing nitrogen-doped titanium dioxide is as follows: The difference from Preparation Example 1 is that the heat treatment does not adopt a three-step heat treatment, but adopts a conventional heat treatment as shown in the following table.

[0066] Table 1 Heat treatment parameters of Preparation Example 9

[0067] Temperature range Atmosphere Time Pre-drying 120℃ Air 1 hour Main annealing 450℃ Nitrogen 3 hours Example 1

[0068] A method for preparing an anti-fouling and antibacterial coating for spectacle lenses:

[0069] Prepare the following raw materials:

[0070] CR-39 resin lens substrate, silane (SiH4, purity ≥99.99%), oxygen (purity ≥99.9%), nanographene (sheet diameter 50-100 nm, thickness ≤5 nm), nanosilver particles (particle size 10-20 nm, purity ≥99.9%), nitrogen-doped titanium dioxide (particle size 5-15 nm, prepared by Preparation Example 1), perfluorooctyltriethoxysilane (FOTS, purity ≥98%), anhydrous ethanol (analytical grade), and a silane coupling agent (KH-550, purity ≥95%).

[0071] Place the lens substrate in the PECVD reaction chamber and evacuate it to a background pressure of ≤1×10 -3 Pa. Silane and oxygen were introduced at a flow ratio of 1:2, maintaining a total pressure of 20 Pa. The RF power supply was turned on at a frequency of 13.56 MHz and a power density of 1.0 W / cm², and the substrate was heated to 250°C. The deposition rate was controlled at 8 nm / min for 12.5 minutes, forming a 100 nm thick silicon dioxide substrate.

[0072] Weigh 0.2g of nanographene and 0.1g of silver nanoparticles and add 50mL of anhydrous ethanol. Add 0.2g of a silane coupling agent and 0.02g of nitrogen-doped titanium dioxide. Ultrasonic dispersion is performed at 40kHz and 150W for 60 minutes to obtain a homogeneous suspension. The suspension is then dropwise applied to the surface of a silica substrate and spin-coated at 2000rpm for 30 seconds. Curing is then performed on a hot plate at 140°C for 1 hour to form an antibacterial coating.

[0073] The antibacterial layer was etched using a reactive ion etch (RIE) system. A CF₄ / O₂ mixture with a flow ratio of 3:1 and a total flow rate of 40 sccm was used. The RIE power was set at 100W, a chamber pressure of 15Pa, an etching depth of 150nm, and honeycomb-shaped fractal grooves. A 0.3T alternating magnetic field was applied simultaneously during the etching process to induce oriented alignment of the silver nanoparticles.

[0074] The reactive ion etching (RIE) equipment was powered down to 30W for secondary etching, maintaining a CF4 / O2 flow ratio of 3:1 to form columnar grooves with a depth of 60nm.

[0075] The etched lens was placed in a vapor deposition furnace and the temperature inside the furnace was raised to 90°C. Perfluorooctyltriethoxysilane vapor was introduced with argon as the carrier gas at a flow rate of 50 mL / min for 2 hours to obtain a hydrophobic layer with a thickness of 20-30 nm.

[0076] Example 2

[0077] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that nano-graphene and nano-silver particles are dispersed in an ethanol solvent at a mass ratio of 1:1.

[0078] Example 3

[0079] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that nano-graphene and nano-silver particles are dispersed in an ethanol solvent at a mass ratio of 3:1.

[0080] Example 4

[0081] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the power density in plasma enhanced chemical vapor deposition treatment is 0.5 W / cm².

[0082] Example 5

[0083] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the power density in plasma enhanced chemical vapor deposition treatment is 1.5 W / cm².

[0084] Example 6

[0085] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the gas flow ratio in reactive ion etching is CF4:O2 = 2:1.

[0086] Example 7

[0087] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the gas flow ratio in reactive ion etching is CF4:O2 = 4:1.

[0088] Example 8

[0089] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the etching gas used in reactive ion etching is CF 4。

[0090] Example 9

[0091] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the etching gas used in reactive ion etching is O2.

[0092] Example 10

[0093] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that an alternating magnetic field with an intensity of 0.1 T is applied to the etching area during reactive ion etching.

[0094] Example 11

[0095] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that an alternating magnetic field with an intensity of 0.5 T is applied to the etching area during the reactive ion etching process.

[0096] Example 12

[0097] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that no alternating magnetic field is applied to the etching area during the reactive ion etching process.

[0098] Example 13

[0099] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that no secondary etching is carried out.

[0100] Example 14

[0101] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the addition amount of nitrogen-doped titanium dioxide is 0.01 g.

[0102] Example 15

[0103] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the addition amount of nitrogen-doped titanium dioxide is 0.03 g.

[0104] Examples 16 - 24

[0105] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that the nitrogen-doped titanium dioxide is successively prepared from Preparation Examples 2 - 9.

[0106] Comparative Example 1

[0107] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that no silica substrate deposition is carried out on the coating.

[0108] Comparative Example 2

[0109] A preparation method of an anti-fouling and antibacterial spectacle lens coating: The difference from Example 1 is that 0.3 g of nano silver particles are weighed and added to 50 mL of absolute ethanol. 0.2 g of silane coupling agent and 0.02 g of nitrogen-doped titanium dioxide are added, and ultrasonic dispersion is carried out for 60 minutes at 40 kHz and a power of 150 W to obtain a homogeneous suspension. The suspension is dropped onto the surface of the silica substrate and spin-coated at 2000 rpm for 30 seconds. It is cured on a hot plate at 140 °C for 1 hour to form an antibacterial layer.

[0110] Comparative Example 3

[0111] Preparation method of an anti-fouling and antibacterial spectacle lens coating: Different from Example 1, it does not undergo etching treatment, and perfluorooctyltriethoxysilane is directly grafted onto the surface by chemical vapor deposition.

[0112] Performance detection test

[0113] Antibacterial rate: According to the ISO22196 standard, the 24-hour antibacterial rate against Staphylococcus aureus (ATCC6538) and Escherichia coli (ATCC25922) was tested.

[0114] Water contact angle: According to the ISO27448 standard, a contact angle measuring instrument was used to measure the static contact angle and the rolling angle.

[0115] Light transmittance: The light transmittance of the coating was tested using an ultraviolet-visible spectrophotometer (wavelength 550 nm).

[0116] After 90 days of simulated daily use, its antibacterial property and water contact angle were measured again. The simulated daily use included placing it in a natural exposed environment and wiping it once every 6 hours with Yijiexin disposable anti-fog lens wipes (composition: all-wood pulp wet-strength paper, non-ionic surfactant, deionized water). When wiping, wipe in a spiral shape from the center outwards.

[0117] Table 2 Detection data

[0118] 24h antibacterial rate 90-day antibacterial rate Initial contact angle 90-day contact angle Light transmittance Staphylococcus aureus / Escherichia coli Staphylococcus aureus / Escherichia coli (°) (°) (%) Example 1 99.9% / 99.8% 98.5% / 98.2% 165 162 98 Example 2 99.7% / 99.6% 97.8% / 97.5% 160 157 97 Example 3 99.5% / 99.3% 97.2% / 96.8% 163 160 97.5 Example 4 99.2% / 99.0% 95.0% / 94.5% 158 153 96 Example 5 98.8% / 98.5% 94.2% / 93.8% 155 150 95.5 Example 6 99.0% / 98.8% 96.0% / 95.5% 162 158 97.8 Example 7 98.5% / 98.3% 95.5% / 95.0% 159 155 97.2 Example 8 97.5% / 97.0% 90.2% / 89.5% 148 142 94 Example 9 96.0% / 95.5% 88.0% / 87.0% 140 135 93.5 Example 10 99.3% / 99.1% 97.0% / 96.5% 163 159 97.5 Example 11 99.6% / 99.4% 97.5% / 97.0% 164 161 97.8 Example 12 98.0% / 97.8% 93.5% / 93.0% 156 150 96.5 Example 13 98.5% / 98.2% 94.0% / 93.5% 152 146 96 Example 14 99.1% / 98.9% 96.5% / 96.0% 161 157 97.5 Example 15 99.4% / 99.2% 97.2% / 96.8% 164 160 97.8 Example 16 99.7% / 99.5% 97.8% / 97.3% 164 160 97.8 Example 17 99.6% / 99.4% 97.5% / 97.0% 163 159 97.5 Example 18 99.3% / 99.1% 97.0% / 96.5% 162 158 97.2 Example 19 99.0% / 98.8% 96.5% / 96.0% 161 156 97 Example 20 98.8% / 98.5% 96.0% / 95.5% 160 155 96.8 Example 21 98.5% / 98.2% 95.5% / 95.0% 159 154 96.5 Example 22 98.0% / 97.8% 94.5% / 94.0% 157 152 96 Example 23 97.5% / 97.0% 93.0% / 92.5% 155 150 95.5 Example 24 96.5% / 96.0% 89.0% / 88.5% 150 143 94.5 Comparative Example 1 85.0% / 83.0% 70.0% / 68.0% 130 115 97 Comparative Example 2 99.9% / 99.8% 85.0% / 83.0% 145 130 94 Comparative Example 3 92.0% / 90.5% 80.0% / 78.0% 115 100 95

[0119] Combining Example 1 and Comparative Example 1 and referring to Table 2, it can be seen that in Comparative Example 1, the silica substrate was not deposited, and its initial antibacterial rate was significantly lower than that of Example 1. Moreover, after 90 days, the antibacterial performance decreased significantly to less than 70%. This indicates that the dense structure formed by the silica substrate through PECVD enhanced the adhesion of the antibacterial layer to the lens body, thereby ensuring the mechanical stability of the coating. The absence of the base layer led to the direct contact of the antibacterial agent with the resin surface, resulting in poor interfacial compatibility and easy peeling due to stress concentration.

[0120] Combining Example 1 and Comparative Example 2 and referring to Table 2, it can be seen that in Comparative Example 2, only nano-silver was added, and its 90-day antibacterial rate decreased significantly compared to Example 1. This shows that although increasing the silver content can improve the antibacterial property in the short term, excessive silver particles are more likely to agglomerate or migrate and lose during long-term wiping, resulting in functional attenuation.

[0121] Combining Example 1 and Comparative Example 3 and referring to Table 2, it can be seen that in Comparative Example 3, no etching treatment was carried out, and both its initial contact angle and the contact angle after 90 days were much lower than those in Example 1, and the antibacterial rate decreased significantly. This indicates that the micro-nano rough structure constructed by reactive ion etching is the key to the efficient grafting of the hydrophobic layer: the honeycomb-shaped grooves formed by etching increase the specific surface area and the air entrapment effect, enabling perfluorosilane molecules to form a continuous low surface energy coverage layer to achieve superhydrophobicity; at the same time, the structure exposes more antibacterial active sites, enhancing the contact efficiency between the antibacterial agent and bacteria.

[0122] Combining Examples 1-3 and referring to Table 2, it can be seen that when the ratio of nano-graphene to silver increases from 1:1 to 3:1, the initial antibacterial rate slightly decreases from 99.7% / 99.6% to 99.5% / 99.3%, but the light transmittance remains above 97%. This shows that the two-dimensional structure of graphene can synergistically inhibit the rapid release of silver ions through physical barrier and chemical adsorption, prolonging the antibacterial timeliness. The design of the mass ratio (1-3):1 achieves a balance between antibacterial efficiency and long-term effectiveness.

[0123] Combining Example 1 and Examples 4-5 and referring to Table 2, it can be seen that low power results in insufficient plasma energy, reduced compactness of the SiO2 base layer, and increased surface defects; high power causes over-etching, increased substrate roughness, and intensified light scattering. Limiting the power density to 0.5-1.5 W / cm² can optimize the deposition rate and film quality.

[0124] Combining Example 1 and Examples 6-9 and referring to Table 2, it can be seen that in the CF4 / O2 mixed gas, the chemical oxidation of O2 softens the etching interface, while the physical bombardment of CF4 enhances the anisotropic etching. The flow ratio of (2-4):1 can balance the etching directionality and structural fidelity, avoiding over-etching or structural collapse caused by pure gases.

[0125] Combining Example 1 and Examples 10-12 and referring to Table 2, it can be seen that when a magnetic field of 0.3 T is applied, both the antibacterial rate and the contact angle are better than those without a magnetic field. The magnetic field induces the directional alignment of nano-silver along the magnetic field lines to form a conductive network, inhibiting the electrostatic adsorption of dust; at the same time, it optimizes the anisotropic distribution of the honeycomb structure, enabling the antibacterial agent to be enriched on the surface of the micro-columns, increasing the active area. However, when the magnetic field strength exceeds 0.5 T, it will exacerbate the particle migration, resulting in a slight decrease in the light transmittance.

[0126] Combining Example 1 and Example 13 and referring to Table 2, it can be seen that in Example 13, no secondary etching was carried out, and its contact angle decreased by 13° compared with Example 1, and the antibacterial rate after 90 days decreased by 4.5%. This indicates that the secondary nano-texture formed by secondary etching further increases the grafting density of the hydrophobic layer, enhances the stability of the Cassie-Baxter state, and reduces pollutant penetration through multi-level roughness design; at the same time, the nano-scale grooves can fix more antibacterial agents and delay their loss.

[0127] Combined with Example 1 and Examples 14-15 and Table 2, it can be seen that appropriate amount of TiO2 generates reactive oxygen species (ROS) under visible light, and synergistically destroys the bacterial membrane with silver ions. However, excessive addition causes light scattering due to particle aggregation, which instead reduces the light transmittance. A preferred addition amount of 10-30% can balance the photocatalytic activity and optical properties.

[0128] Combined with Example 1 and Examples 16-24 and Table 2, it can be seen that the N-TiO2 prepared in Preparation Example 1 has the best performance, while the antibacterial rates and contact angles of Preparation Examples 8 and 9 decrease significantly. This indicates that hydrogen-assisted reduction in the three-stage annealing can generate oxygen vacancies, inhibit the recombination of photo-generated carriers, and improve the photocatalytic efficiency; while conventional annealing leads to uneven nitrogen doping, grain coarsening, and weakened visible light response. Optimizing the nitrogen doping process is crucial for the long-term antibacterial property of the coating.

[0129] This specific embodiment is only an interpretation of the present application and does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A preparation method of an anti-fouling and antibacterial spectacle lens coating, characterized in that, It includes the following steps: Deposit a silica substrate with a thickness of 50 - 100 nm on the lens surface by plasma-enhanced chemical vapor deposition treatment; Disperse nano-graphene and nano-silver particles in an ethanol solvent at a mass ratio of (1 - 3):1, then add a silane coupling agent to form a homogeneous suspension. Nitrogen-doped titanium dioxide with a particle size of 5 - 15 nm is also added to the suspension, and the addition amount of the nitrogen-doped titanium dioxide is 10 - 30% of the mass of nano-silver. The suspension is loaded on the surface of the silica substrate by spin coating and cured by heat treatment at 120 - 150 °C to form an antibacterial layer, where the nano-silver loading amount ≤ 0.5 wt%; Perform etching treatment on the surface of the antibacterial layer by reactive ion etching method, with an etching power of 80 - 120 W and an etching depth of 100 - 200 nm. Subsequently, graft perfluorooctyltriethoxysilane on the etched surface at 80 - 100 °C by vapor deposition method to form a hydrophobic layer; The preparation method of the nitrogen-doped titanium dioxide is as follows: Mix tetrabutyl titanate and absolute ethanol at a volume ratio of 1:(3 - 5), add citric acid, and the molar ratio of citric acid to tetrabutyl titanate is 1:(10 - 20) to obtain solution A; Dissolve urea in deionized water to prepare solution B with a concentration of 0.5 - 1.5 mol / L; Dropwise add solution B into solution A, and the volume ratio of solution A to solution B added is (5 - 3):

1. Use microwave with a power of 300 - 500 W, a temperature of 80 - 100 °C, and a reaction time of 20 - 40 minutes to obtain a gel; Perform the following three-stage heat treatment on the gel in sequence: The first stage: Keep warm in an air atmosphere at 200 - 250 °C for 1 - 1.2 hours; The second stage: Keep warm in a nitrogen atmosphere at 350 - 400 °C for 2 - 2.2 hours; The third stage: Anneal in an argon atmosphere at 500 - 550 °C and keep warm for 30 - 40 minutes; Ball mill and screen the annealed product to obtain nitrogen-doped titanium dioxide with a particle size of 5 - 15 nm.

2. The preparation method of the anti-fouling and antibacterial spectacle lens coating according to claim 1, characterized in that: The radio frequency power supply frequency of the plasma-enhanced chemical vapor deposition treatment is 13.56 MHz, the power density is 0.5 - 1.5 W / cm², and the deposition rate is 5 - 10 nm / min.

3. The preparation method of the anti-fouling and antibacterial spectacle lens coating according to claim 1, wherein: The etching gas used in the reactive ion etching is a CF4 / O2 mixed gas, and the gas flow ratio of the reactive ion etching is CF4:O2 = (2 - 4):

1.

4. The preparation method of the anti-fouling and antibacterial spectacle lens coating according to claim 1, characterized in that: Apply an alternating magnetic field with an intensity of 0.1 - 0.5 T to the etching area during the reactive ion etching process.

5. The preparation method of the anti-fouling and antibacterial spectacle lens coating according to claim 1, characterized in that: After the etching treatment on the surface of the antibacterial layer, secondary etching is required. The power of the secondary etching is 20 - 40 W and the etching depth is 40 - 80 nm.

6. The preparation method of the anti-fouling and antibacterial spectacle lens coating according to claim 1, characterized in that: Introduce hydrogen with a volume fraction of 5 - 10% into argon during the annealing process in the third stage.