Silica hydrogel material as well as preparation method and application thereof

Abstract

The invention discloses a silicon hydrogel material as well as a preparation method and application thereof. The preparation method comprises the following steps: curing and molding 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy) propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), a silane coupling agent and a photoinitiator through a photopolymerization reaction to obtain a silicon hydrogel substrate; performing oxygen plasma treatment; preparing a PDMS hydrophobic layer; performing oxygen plasma treatment; soaking in an organic solution containing a hydrophobic initiator; and forming a hydrophilic polymer layer. The high oxygen permeability, long-acting moisture retention, low friction and protein deposition resistance of the lens are realized by constructing a'hydrophobic water locking-hydrophilic lubrication 'double-layer functional interface.

Description

Technical Field

[0001] This invention belongs to the field of biomedical polymer materials and ophthalmic medical devices, and particularly relates to a silicone hydrogel material, its preparation method and application. Background Technology

[0002] Silicone hydrogel materials, due to their combination of high water content and excellent oxygen permeability, are widely used in contact lenses, bandage lenses, and biological soft tissue replacement materials. Existing silicone hydrogel bandage lenses typically utilize a copolymer system of hydroxyethyl methacrylate (HEMA) containing organosilicon monomers (such as 3-(trimethylsiloxy)propyl methacrylate, TRIS), prepared through photo-initiated polymerization or thermally initiated polymerization. This process ensures high oxygen permeability while maintaining appropriate softness. However, in actual clinical use, traditional silicone hydrogel bandage lenses generally suffer from the following problems: First, their strong surface hydrophobicity leads to poor tear wetting and rapid evaporation, causing lens surface dryness and discomfort. Second, their high surface friction coefficient easily damages the corneal epithelium during repeated eyelid rubbing. Third, the hydrophobic interface easily adsorbs protein and lipid impurities, affecting lens light transmittance and biocompatibility, limiting their long-term use in patients with dry eye and for postoperative care.

[0003] To improve the wetting properties and surface friction characteristics of silicone hydrogel materials, researchers have proposed various modification strategies, including copolymerization to introduce hydrophilic monomers, surface plasma treatment, surface coating with hydrophilic polymers, and mixed modification with hydrophilic additives (such as polyethylene glycol PEG, polyvinylpyrrolidone PVP, etc.). However, these methods generally have the following drawbacks: copolymerization modification reduces the proportion of silicon-oxygen segments, leading to a significant decrease in oxygen permeability; plasma treatment has a short-lived effect and is prone to decay over time; surface-coated modified layers have poor adhesion and are easily peeled off during wear or washing; additive modification can easily cause phase separation in the system, resulting in a decrease in mechanical properties and optical uniformity. Therefore, how to maintain high oxygen permeability while simultaneously achieving long-term stable moisture retention and low friction remains a key challenge in the research of silicone hydrogel bandage lenses. Summary of the Invention

[0004] The technical problem this invention aims to solve is that existing silicone hydrogel bandage lenses suffer from poor surface wettability, high coefficient of friction, insufficient moisturizing performance, and severe protein deposition. Therefore, this invention provides a silicone hydrogel material, its preparation method, and its application in contact lens manufacturing. The preparation method provided by this invention is simple and highly controllable, resulting in a clean and highly stable silicone hydrogel material with both superhydrophilicity and a low coefficient of friction. The silicone hydrogel material provided by this invention significantly improves the hydrophilicity and lubricity of the material surface while maintaining high oxygen permeability, thereby achieving long-term wearing comfort and biocompatibility, and further enabling applications in corneal repair, adjunctive treatment of dry eye syndrome, and postoperative protection.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On one hand, the present invention provides a method for preparing a silicone hydrogel material, comprising the following steps: 1) A silicone hydrogel substrate is obtained by photopolymerization of 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy)propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), silane coupling agent, and photoinitiator; or a silicone hydrogel substrate is obtained by photopolymerization of 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy)propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), N-vinylpyrrolidone (NVP), silane coupling agent, and photoinitiator. 2) The silica hydrogel substrate obtained in step 1) is subjected to oxygen plasma treatment; 3) Prepare a hydrophobic layer on the surface of the silicone hydrogel substrate after the treatment in step 2); the hydrophobic layer is polydimethylsiloxane (PDMS). 4) Perform oxygen plasma treatment on the PDMS layer obtained in step 3); 5) Immerse the sample treated with oxygen plasma in step 4) in an organic solution containing a hydrophobic initiator; 6) Immerse the sample obtained in step 5) in an aqueous solution containing hydrophilic monomers and water-soluble initiators to form a hydrophilic polymer layer through polymerization reaction.

[0006] In a preferred embodiment, in step 1), the silane coupling agent is methacryloyloxypropyltrimethoxysilane; Preferably, the photoinitiator is selected from either 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) or Irgacure-2959; Preferably, the mass ratio of 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy)propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), N-vinylpyrrolidone (NVP), silane coupling agent, and photoinitiator is 80~95:1~10:1~2:0~20:0.5~5:0.3~0.7, and more preferably 80~95:1~10:1~2:10~20:0.5~5:0.3~0.7; Preferably, the conditions for the photopolymerization reaction are: ultraviolet light intensity of 200~500 mW / cm². 2 The reaction time is 30s to 60min, preferably 5 to 30min; Preferably, the photopolymerization reaction is carried out under oxygen-free conditions.

[0007] In some specific embodiments, the thickness of the silicone hydrogel substrate is 100~300 µm.

[0008] In the technical solution of the present invention, 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy)propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), silane coupling agent and photoinitiator are cured and molded through photopolymerization reaction to obtain a transparent and dense silicone hydrogel substrate with high oxygen permeability, high mechanical stability and excellent lubrication performance.

[0009] In a preferred embodiment, in step 2), the power of the oxygen plasma treatment is 30-60 W, and the treatment time is 2-5 min. In the technical solution of this invention, oxygen plasma treatment can introduce hydrophilic functional groups such as hydroxyl and carboxyl groups onto the surface, thereby achieving surface activation.

[0010] In a preferred embodiment, step 3) involves preparing the hydrophobic layer by mixing PDMS with a curing agent and coating the mixture onto the surface of the silicone hydrogel substrate treated in step 2), followed by curing to form a hydrophobic layer. Preferably, the coating is spin-coating; Preferably, the spin coating speed is 500~4000 rpm; the spin coating time is 5~130 s; In some specific embodiments, the spin coating is a step-by-step spin coating, specifically, spin coating at a rate of 500-1500 rpm for 5-10 s, followed by spin coating at a rate of 2000-4000 rpm for 30-120 s. Preferably, the curing temperature is 60~100℃ and the curing time is 1~4 h.

[0011] In some specific embodiments, the static water contact angle of the hydrophobic layer prepared in step 3) is 110~130°, and the oxygen permeability coefficient Dk is 600~900 barrer.

[0012] In some specific embodiments, after step 3), there is also a washing and nitrogen drying step; the washing is isopropanol cleaning and water rinsing.

[0013] In a preferred embodiment, in step 4), the power of the oxygen plasma treatment is 30-60 W, and the treatment time is 2-5 min. In the technical solution of this invention, active silicon-oxygen functional groups are obtained through oxygen plasma treatment, enhancing the bonding force of subsequent grafting reactions.

[0014] In a preferred embodiment, in step 5), the hydrophobic initiator is a photoinitiator or a thermal initiator; the photoinitiator is benzophenone; the thermal initiator is benzoyl peroxide; the solvent of the organic solution containing benzophenone is an ethanol solution or isopropanol; the solvent of the organic solution containing benzoyl peroxide is acetone. Preferably, in the organic solution containing the hydrophobic initiator, the concentration of the hydrophobic initiator is 5-15 wt.%; Preferably, the soaking time is 3 to 5 minutes.

[0015] In the technical solution of the present invention, in step 5), after soaking, photosensitive initiating groups or thermosensitive initiating groups can be introduced on the substrate surface to form a hydrophobic initiating layer with photoinitiating activity or thermoinitiating activity.

[0016] In a preferred embodiment, in step 6), the hydrophilic monomer is a photoinitiating monomer or a thermal initiating monomer; the water-soluble initiator is a photoinitiator or a thermal initiator. Preferably, the photoinitiating monomer is selected from at least one of 2-hydroxyethyl methacrylate (HEMA), acrylamide (AAm), acrylic acid (AA), N-vinylpyrrolidone (VP), and N,N-dimethylacrylamide (DMAA); Preferably, the thermally initiated monomer is selected from at least one of acrylamide (AAm), acrylic acid (AA), and N,N-dimethylacrylamide (DMAA); Preferably, the photoinitiator is Irgacure-2959; Preferably, the thermal initiator is ammonium persulfate; Preferably, in the aqueous solution containing the hydrophilic monomer and the water-soluble initiator, the concentration of the hydrophilic monomer is 15-25 wt.%, and the concentration of the water-soluble initiator is 0.1-1 wt.%, preferably 0.5-1 wt.%. Preferably, the thickness of the hydrophilic polymer layer is 10~50 µm.

[0017] In the technical solution of the present invention, when the hydrophobic initiator in step 5) is a photoinitiator, the water-soluble initiator in step 6) is also a photoinitiator; when the hydrophobic initiator in step 5) is a thermal initiator, the water-soluble initiator in step 6) is also a thermal initiator.

[0018] In the technical solution of the present invention, in step 6), the polymerization reaction is a photopolymerization reaction or a thermal polymerization reaction; the conditions for the photopolymerization reaction are under ultraviolet irradiation for 40-60 min; the conditions for the thermal polymerization reaction are polymerization at room temperature to 90°C for 70-100 min.

[0019] In the technical solution of the present invention, a dual-layer functional interface of "hydrophobic water-locking and hydrophilic lubrication" can be obtained through steps 5) and 6).

[0020] In some specific embodiments, step 6) further includes cleaning and stabilization treatment; the cleaning is soaking in water to remove unreacted monomers, initiators and oligomers; the stabilization treatment is drying to fix the form; the soaking time is 20-30 h, and the water is changed every 4-6 h; the soaking time is preferably 12-24 h; the drying is natural drying or oven drying, preferably oven drying; the drying temperature is 40-60℃.

[0021] In another aspect, the present invention provides a silica hydrogel material obtained by the above preparation method.

[0022] In another aspect, the present invention provides the application of the above-described preparation method or the above-described silicone hydrogel material in the preparation of contact lenses.

[0023] Preferably, its application in the preparation of bandage lenses.

[0024] This invention forms a highly oxygen-permeable hydrophobic layer on the surface of a silicone hydrogel substrate, and then grafts hydrophilic monomers in situ onto the hydrophobic layer using a hydrophobic initiator to form a stable hydrophilic polymer layer, thereby constructing a "hydrophobic-water-locking-hydrophilic-lubricating" composite interface to achieve synergistic regulation of multiple properties. The silicone hydrogel material provided by this invention can effectively reduce the coefficient of friction, delay tear evaporation with the help of the hydrophobic layer, and significantly reduce protein deposition, thus possessing high oxygen permeability, high moisture retention, low friction, and excellent biocompatibility.

[0025] Compared with the prior art, the present invention has the following outstanding technical effects and advantages: (1) This invention is the first to adopt a two-layer modification strategy of "hydrophobic initiator grafting-in-situ hydrophilic polymerization", which significantly improves surface wettability and frictional stability while maintaining the high oxygen permeability of the silicone hydrogel. (2) The “hydrophobic-water-hydrophilic lubricating” interface formed by the present invention can effectively reduce tear evaporation and lower the coefficient of friction, thereby enhancing wearing comfort; (3) The hydrophilic polymer layer in this invention is covalently bonded, which has excellent stability and anti-peeling properties, and retains superhydrophilic characteristics even after long-term use; (4) The preparation method used in this invention does not require complex instruments and can be completed by relying solely on photopolymerization and plasma treatment. It is simple to operate, produces less pollution, and has high repeatability. (5) The material prepared by the present invention has high oxygen permeability, low friction, long-lasting moisturizing properties and good biocompatibility. The bandage lens prepared by it can be molded according to the curvature design. The thickness of its hydrophilic layer is controlled between 10-50 μm, which is particularly suitable for corneal repair, postoperative protection and adjunctive treatment of dry eye syndrome. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the preparation process of the silicone hydrogel bandage lens in this embodiment of the invention.

[0027] Figure 2 This is a graph showing the thickness test results of the lens sample prepared in the first step of Embodiment 1 of the present invention.

[0028] Figure 3 This is a graph showing the thickness test results of the lens sample prepared in step eight of Embodiment 1 of the present invention.

[0029] Figure 4 This is a diagram showing the contact angle test results of the material after the second step of oxygen plasma surface activation treatment in Embodiment 2 of the present invention.

[0030] Figure 5 This is a diagram showing the contact angle test results after spin-coating the PDMS hydrophobic layer in the third step of Embodiment 2 of the present invention.

[0031] Figure 6 This is a diagram showing the contact angle test results of the hydrophilic monomer prepared in the fifth step of Example 2 of the present invention after polymerization.

[0032] Figure 7 This is a graph showing the relationship between the mass fraction of PDMS and the thickness of the hydrophobic layer during spin coating in this invention.

[0033] Figure 8 This is a diagram showing the comparative experimental results of the evaporation behavior of artificial tears in Example 3 of the present invention. Detailed Implementation

[0034] The following embodiments are merely some, not all, of the embodiments of the present invention. Therefore, the detailed descriptions of the embodiments provided below are not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] In this invention, unless otherwise specified, all equipment and raw materials are commercially available or commonly used in the industry. The methods described in the following embodiments are conventional methods in the art, unless otherwise specified.

[0036] The PDMS and curing agent used in the following examples are Dow Corning Sylgard.TM 184; The spin coater is a KW-4T Chinese Academy of Sciences Microelectronics desktop spin coater.

[0037] Example 1 This embodiment provides a silicone hydrogel bandage lens, the preparation process of which is as follows: Figure 1 As shown, the specific steps include: Step 1: Preparation of silica hydrogel substrate Weigh out 6 g of 2-hydroxyethyl methacrylate (HEMA), 0.05 g of methacryloyloxypropyltrimethoxysilane (KH-570), 0.5 g of 3-(trimethylsiloxy)propyl methacrylate (TRIS), 0.11 g of ethylene glycol dimethacrylate (EGDMA), and 29 mg of photoinitiator TPO.

[0038] After mixing the above raw materials evenly and stirring to remove bubbles, the mixture is poured into an acrylic mold. Oxygen is isolated using the cast-molding method. The mixture is then subjected to ultraviolet light at a wavelength of 365 nm and an ultraviolet light intensity of 360 mW / cm². 2 After irradiation for 10 minutes, a transparent silicone hydrogel substrate with a thickness of approximately 150 µm was obtained.

[0039] Step 2: Oxygen plasma surface activation treatment The obtained substrate was placed in a plasma treatment instrument, oxygen was introduced, the power was 30~60 W, and the time was 3 min, so as to introduce functional groups such as -OH on the surface, thereby improving the surface energy and coating adhesion.

[0040] Step 3: Preparation of PDMS hydrophobic coating solution Mix Sylgard at a mass ratio of 10:1 TM Component A (PDMS) and component B (curing agent) of 184 were diluted with n-hexane solvent to a PDMS mass fraction of 80 wt.%, and stirred evenly for later use.

[0041] Step 4: Spin-coating a PDMS hydrophobic layer On a spin coater, the above PDMS solution was uniformly dropped onto the activated substrate surface and spin-coated at 500 rpm for 5 s, then accelerated to 2000 rpm for 30 s. After spin coating, the sample was placed on a 70°C constant temperature heating plate for curing for 3 h, resulting in a hydrophobic layer with a thickness of 26 µm, a surface contact angle of approximately 120°, and an oxygen permeability coefficient Dk of 700 Barrer.

[0042] Step 5: Hydrophilic surface pretreatment Clean with isopropanol and rinse with deionized water; then dry with nitrogen; perform oxygen plasma activation treatment for 3 minutes to introduce active hydroxyl groups.

[0043] Step 6: Grafting Initiator Immerse in an ethanol solution of 10 wt.% benzophenone for 3 min, remove and wash with isopropanol and blow dry to introduce photoinitiating groups on the surface.

[0044] Step 7: Photopolymerization of hydrophilic monomers The sample was immersed in an aqueous solution containing 20 wt.% HEMA and 1 wt.% Irgacure-2959 and irradiated under 365 nm ultraviolet light for 55 min to perform surface photografting polymerization, forming a hydrophilic polymer layer of about 20 µm thickness.

[0045] Step 8: Post-processing The polymerized sample was immersed in deionized water for 24 hours, with the water changed every 6 hours to remove residual monomers, initiators, etc. After removal, it was allowed to air dry at room temperature to obtain a silicone hydrogel bandage lens with a "hydrophobic-water-locking-hydrophilic-lubricating" double-layer interface.

[0046] Example 2 This embodiment provides a silicone hydrogel bandage lens, the preparation process of which is as follows: Figure 1 As shown, the specific steps include: Step 1: Preparation of silica hydrogel substrate Weigh out 10.7 g of 2-hydroxyethyl methacrylate (HEMA), 0.52 g of methacryloyloxypropyltrimethoxysilane (KH-570), 0.2 g of 3-(trimethylsiloxy)propyl methacrylate (TRIS), 0.21 g of ethylene glycol dimethacrylate (EGDMA), 1.5 g of N-vinylpyrrolidone (NVP), and 66 mg of photoinitiator TPO.

[0047] After mixing the above raw materials evenly and stirring to remove bubbles, the mixture is poured into an acrylic mold. Oxygen is isolated using the cast-molding method. The mixture is then subjected to ultraviolet light at a wavelength of 365 nm and an ultraviolet light intensity of 40 mW / cm². 2 After irradiation for 20 minutes, a transparent silicone hydrogel substrate with a thickness of approximately 100 µm was obtained.

[0048] Step 2: Oxygen plasma surface activation treatment In a plasma treatment instrument, oxygen was introduced for 3 min at a power of 30~60 W to introduce -OH functional groups.

[0049] Step 3: Spin-coating PDMS hydrophobic layer Mix Sylgard at a mass ratio of 10:1 TMComponent A (PDMS) and component B (curing agent) of 184 were diluted to 70%, degassed under vacuum, and then spin-coated on an activated substrate: spin-coated at 500 rpm for 5 s, and then at 2500 rpm for 30 s; after spin-coating, the substrate was cured at 70°C for 3 h to obtain a hydrophobic layer with a thickness of 21 µm, a static contact angle of 120°, and an oxygen permeability coefficient Dk of 700 Barrer.

[0050] Step 4: Hydrophilic surface pretreatment and grafting initiator The sample was cleaned with isopropanol and rinsed with deionized water; then dried with nitrogen; after being treated with oxygen plasma for 3 min, the sample was immersed in a 10 wt.% benzophenone ethanol solution for 3 min to introduce photosensitive groups on the surface; after removal, it was cleaned with isopropanol and dried.

[0051] Step 5: Photopolymerization of hydrophilic monomers The sample was immersed in an aqueous solution containing 20 wt.% N-vinylpyrrolidone (NVP) and 1 wt.% Irgacure-2959 and irradiated under 365 nm ultraviolet light for 55 min to perform surface photografting polymerization, forming a hydrophilic polymer layer of about 20 µm thickness.

[0052] The friction coefficient of the hydrophilic polymer layer prepared in this step is 0.019.

[0053] Step 6: Post-processing The polymer sample was soaked in deionized water for 30 hours, with the water changed every 5 hours to remove residual monomers, etc., to obtain a silicone hydrogel bandage lens, which was then stored in contact lens solution.

[0054] Example 3 This embodiment provides a silicone hydrogel bandage lens, the preparation process of which is as follows: Figure 1 As shown, the specific steps include: Step 1: Preparation of silica hydrogel substrate Weigh out 5.35 g of 2-hydroxyethyl methacrylate (HEMA), 0.104 g of methacryloyloxypropyltrimethoxysilane (KH-570), 0.2 g of 3-(trimethylsiloxy)propyl methacrylate (TRIS), 0.11 g of ethylene glycol dimethacrylate (EGDMA), and 29 mg of photoinitiator TPO.

[0055] After mixing the above raw materials evenly and stirring to remove bubbles, the mixture is poured into an acrylic mold. Oxygen is isolated using the cast-molding method. The mixture is then subjected to ultraviolet light at a wavelength of 365 nm and an ultraviolet light intensity of 400 mW / cm². 2 After irradiation for 5 minutes, a transparent silicone hydrogel substrate with a thickness of approximately 150 µm was obtained.

[0056] Step 2: Oxygen plasma surface activation treatment The obtained substrate was placed in a plasma treatment instrument, oxygen was introduced, the power was 30~60 W, and the time was 3 min.

[0057] Step 3: Spin-coating PDMS hydrophobic layer Mix Sylgard at a mass ratio of 10:1 TM Component A (PDMS) and component B (curing agent) of 184 were diluted to 90%, degassed under vacuum, and then spin-coated on an activated substrate: spin-coated at 2000 rpm for 30 s; cured at 70°C for 3 h to obtain a hydrophobic layer with a thickness of 38 µm, a static contact angle of 126.2°, and an oxygen permeability coefficient Dk of 700 Barrer.

[0058] Step 4: Hydrophilic surface pretreatment and grafting initiator The sample was cleaned with isopropanol, rinsed with deionized water, and dried with nitrogen. After being treated with oxygen plasma for 3 min, the sample was immersed in an acetone solution of 10 wt.% benzoyl peroxide (BPO) for 5 min to introduce thermally initiating groups on the surface. After removal, the sample was cleaned with isopropanol and dried.

[0059] Step 5: Thermal polymerization of hydrophilic monomers The sample was immersed in an aqueous solution containing 20 wt.% N,N-dimethylacrylamide (DMAA) and 1 wt.% APS (ammonium persulfate) and reacted at 80°C for 90 min to obtain a hydrophilic polymer layer with a thickness of about 30 µm.

[0060] Step 6: Post-processing The polymerized sample was immersed in deionized water for 24 hours, with the water changed every 6 hours to remove residual reactants; it was then removed and allowed to air dry. The final product was a silicone hydrogel bandage lens with a superhydrophilic surface, low coefficient of friction, and high oxygen permeability.

[0061] Performance testing 1. Figure 2 The image shows the thickness test results (in mm) of the lens sample prepared in the first step of Example 1. Figure 3 The image shows the thickness test results (in mm) of the lens sample prepared in step eight of Example 1.

[0062] 2. Figure 4 The figure shown is a test result of the contact angle of the material after the second step of oxygen plasma surface activation treatment in Example 2; Figure 5 The image shows the contact angle test results after spin-coating the PDMS hydrophobic layer in the third step of Example 2 (in the image, the contact angle on the left is 126.2° and the contact angle on the right is 120.3°). Figure 6This is a graph showing the contact angle test results after the polymerization of hydrophilic monomers in step 5 of Example 2.

[0063] 3. Figure 7 The figure shows the film thickness test results of PDMS hydrophobic layers prepared with PDMS mass fraction and other PDMS mass fractions in the embodiments of the present invention.

[0064] 4. Figure 8 The figure shows the comparative experimental results of the artificial tear evaporation behavior of the silicone hydrogel bandage lens prepared in Example 3.

[0065] In summary, the silicone hydrogel material prepared by this invention has the advantages of high oxygen permeability, low friction, long-lasting moisturizing properties and good biocompatibility, and has potential application value in corneal repair, postoperative protection and adjunctive treatment of dry eye syndrome.

[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a silica hydrogel material, characterized in that, Includes the following steps: 1) A silicone hydrogel substrate is obtained by photopolymerization of 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy)propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), silane coupling agent, and photoinitiator; or a silicone hydrogel substrate is obtained by photopolymerization of 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy)propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), N-vinylpyrrolidone (NVP), silane coupling agent, and photoinitiator. 2) The silica hydrogel substrate obtained in step 1) is subjected to oxygen plasma treatment; 3) Prepare a hydrophobic layer on the surface of the silicone hydrogel substrate after the treatment in step 2); the hydrophobic layer is polydimethylsiloxane (PDMS). 4) Perform oxygen plasma treatment on the PDMS layer obtained in step 3); 5) Immerse the sample treated with oxygen plasma in step 4) in an organic solution containing a hydrophobic initiator; 6) Immerse the sample obtained in step 5) in an aqueous solution containing hydrophilic monomers and water-soluble initiators to form a hydrophilic polymer layer through polymerization reaction.

2. The preparation method according to claim 1, characterized in that, In step 1), the silane coupling agent is methacryloyloxypropyltrimethoxysilane; Preferably, the photoinitiator is selected from either 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) or Irgacure-2959; Preferably, the mass ratio of 2-hydroxyethyl methacrylate (HEMA), 3-(trimethylsiloxy)propyl methacrylate (TRIS), ethylene glycol dimethacrylate (EGDMA), N-vinylpyrrolidone (NVP), silane coupling agent, and photoinitiator is 80~95:1~10:1~2:0~20:0.5~5:0.3~0.7, and more preferably 80~95:1~10:1~2:10~20:0.5~5:0.3~0.7; Preferably, the conditions for the photopolymerization reaction are: ultraviolet light intensity of 200~500 mW / cm². 2 The reaction time is 30s to 60min, preferably 5 to 30min; Preferably, the photopolymerization reaction is carried out under oxygen-free conditions.

3. The preparation method according to claim 1, characterized in that, In step 2), the power of the oxygen plasma treatment is 30~60 W, and the treatment time is 2~5 min.

4. The preparation method according to claim 1, characterized in that, In step 3), the step of preparing the hydrophobic layer is as follows: PDMS is mixed with a curing agent and then coated onto the surface of the silicone hydrogel substrate treated in step 2), and after curing, a hydrophobic layer is formed; Preferably, the coating is spin-coating; Preferably, the spin coating speed is 500~4000 rpm; the spin coating time is 5~130 s; Preferably, the spin coating is a step-by-step spin coating, specifically, spin coating at a speed of 500-1500 rpm for 5-10 s, followed by spin coating at a speed of 2000-4000 rpm for 30-120 s. Preferably, the curing temperature is 60~100℃, and the curing time is 1~4 h; Preferably, after step 3), the process further includes washing and nitrogen drying; the washing is isopropanol cleaning and water rinsing.

5. The preparation method according to claim 1, characterized in that, In step 4), the power of the oxygen plasma treatment is 30~60 W, and the treatment time is 2~5 min.

6. The preparation method according to claim 1, characterized in that, In step 5), the hydrophobic initiator is a photoinitiator or a thermal initiator; the photoinitiator is benzophenone; the thermal initiator is benzoyl peroxide; the solvent of the organic solution containing benzophenone is an ethanol solution or isopropanol; the solvent of the organic solution containing benzoyl peroxide is acetone. Preferably, in the organic solution containing the hydrophobic initiator, the concentration of the hydrophobic initiator is 5-15 wt.%; Preferably, the soaking time is 3 to 5 minutes.

7. The preparation method according to claim 1, characterized in that, In step 6), the hydrophilic monomer is a photoinitiating monomer or a thermal initiating monomer; the water-soluble initiator is a photoinitiator or a thermal initiator; Preferably, the photoinitiating monomer is selected from at least one of 2-hydroxyethyl methacrylate (HEMA), acrylamide (AAm), acrylic acid (AA), N-vinylpyrrolidone (VP), and N,N-dimethylacrylamide (DMAA); Preferably, the thermally initiated monomer is selected from at least one of acrylamide (AAm), acrylic acid (AA), and N,N-dimethylacrylamide (DMAA); Preferably, the photoinitiator is Irgacure-2959; Preferably, the thermal initiator is ammonium persulfate; Preferably, in the aqueous solution containing the hydrophilic monomer and the water-soluble initiator, the concentration of the hydrophilic monomer is 15-25 wt.%, and the concentration of the water-soluble initiator is 0.1-1 wt.%, preferably 0.5-1 wt.%. Preferably, the thickness of the hydrophilic polymer layer is 10~50 µm.

8. The preparation method according to claim 1, characterized in that, In step 6), the polymerization reaction is a photopolymerization reaction or a thermal polymerization reaction; the conditions for the photopolymerization reaction are under ultraviolet irradiation for 40-60 min; the conditions for the thermal polymerization reaction are polymerization at room temperature to 90°C for 70-100 min. Preferably, step 6) further includes cleaning and stabilization treatment; the cleaning is soaking in water to remove unreacted monomers, initiators and oligomers; the stabilization treatment is drying to fix the form; the soaking time is 20-30 hours, and the water is changed every 4-6 hours; the soaking time is preferably 12-24 hours; the drying is natural drying or oven drying, preferably oven drying; the drying temperature is 40-60°C.

9. The silica hydrogel material obtained by the preparation method according to any one of claims 1-8.

10. The preparation method according to any one of claims 1-8 or the application of the silicone hydrogel material according to claim 9 in the preparation of contact lenses; Preferably, its application in the preparation of bandage lenses.

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