Hydrophilic coating solution, hydrophilic coating layer and manufacturing method thereof
Patent Information
- Application Number
- TW114109886
- Authority / Receiving Office
- TW · TW
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2026-10-01
- Estimated Expiration
- 2045-03-16
AI Technical Summary
Existing medical devices made of hydrophobic materials face issues with biocompatibility due to hydrophobic properties, and existing surface modification or coating methods result in temporary hydrophilicity that diminishes over time, leading to peeling and uneven hydrophilicity, affecting stability and reliability.
A hydrophilic coating comprising a silicate monomer, prepolymer, hydrophilic lubricating material, crosslinking agent, and initiator is applied to the substrate, forming a single-layer structure with siloxane or silane functional groups for covalent bonding, creating an interpenetrating polymer network that prevents peeling and maintains hydrophilicity.
The coating provides long-lasting hydrophilicity, improved biocompatibility, and reduced surface friction, preventing peeling and ensuring stability and reliability of medical devices.
Smart Images
Figure TWG2TA001077482_001 
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Figure TWG2TA001077482_003
Abstract
Description
Technical Field
[0001] This invention relates to a coating, a coating layer and a method for making the same, and particularly to a hydrophilic coating liquid, a hydrophilic coating layer and a method for making the same. Prior Technology
[0002] Many medical devices used in experiments on the market are usually made of materials with good chemical stability and heat resistance (e.g., silicon materials). However, these materials, which are not easily reactive with chemicals, often have hydrophobic properties, which makes their biocompatibility or other functional properties low. This is a limitation for most medical devices.
[0003] Accordingly, professionals in the field typically employ two methods—surface modification or coating—to make the surface of medical device substrates hydrophilic, thereby improving the biocompatibility of the medical devices. Surface modification usually involves treating the substrate surface using plasma technology; however, the hydrophilic effect of this method gradually diminishes over time, limiting the lifespan of the medical device. Coating, on the other hand, involves forming a hydrophilic film on the substrate surface. This typically involves first forming an interface layer for adhesion on the substrate surface, and then coating the hydrophilic film onto this interface layer. However, due to the limited bonding strength between the interface layer and the hydrophilic coating, the hydrophilic film is prone to peeling off during use, resulting in uneven hydrophilicity on the surface of the medical device substrate, affecting its stability and reliability.
[0004] Therefore, how to extend the duration and stability of the hydrophilicity of the surface of hydrophobic substrate materials, thereby extending the service life of medical devices, is a topic of great importance in related fields. Summary of the Invention
[0005] Therefore, the purpose of this invention is to provide a hydrophilic coating that enables the surface of a substrate to exhibit a hydrophilic effect for a long time and stably.
[0006] The hydrophilic coating of the present invention comprises a silicate monomer, a prepolymer, a hydrophilic lubricating material, a crosslinking agent, an initiator, and a solvent.
[0007] The prepolymer is obtained by polymerizing a functional monomer and a hydrophilic monomer, wherein the molar ratio of the functional monomer to the hydrophilic monomer is between 1:30 and 1:55.
[0008] The hydrophilic lubricating material is selected from at least one of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), ethylene oxide (PEO), and hyaluronic acid (HA). The functional monomer and the silicate monomer are silicate derivatives and have at least one active functional group. The active functional group is selected from at least one of vinyl, propylene, methpropylene, phenyl, and epoxy groups. The crosslinking agent is selected from acrylate or acrylamide.
[0009] Another object of the present invention is to provide a method for producing a hydrophilic coating.
[0010] The method for preparing the hydrophilic coating of the present invention is applicable to the hydrophilic coating liquid as described above and includes the following steps.
[0011] Step A involves prepolymerizing a functional monomer and a hydrophilic monomer to obtain a prepolymer, wherein the molar ratio of the functional monomer to the hydrophilic monomer is between 1:30 and 1:55.
[0012] Step B involves mixing the prepolymer, a silicate monomer, a hydrophilic lubricant, a crosslinking agent, and an initiator in a solvent to prepare a hydrophilic coating.
[0013] Step C involves applying the hydrophilic coating liquid to the surface of a substrate and then curing the hydrophilic coating liquid by photocuring or thermal curing to obtain a hydrophilic coating covering the surface of the substrate.
[0014] The hydrophilic coating is a single-layer structure, with at least a portion of its surface having a hydrophilic functional group and a siloxane functional group or a silane functional group. The hydrophilic coating is formed by grafting the siloxane functional group or the silane functional group onto the surface of the substrate.
[0015] Another object of the present invention is to provide a hydrophilic coating.
[0016] The hydrophilic coating of the present invention is obtained by applying the hydrophilic coating liquid as described above to a substrate and curing it, and the hydrophilic coating comprises a coating body.
[0017] The coating body has a single-layer structure, and at least a portion of its surface has a hydrophilic functional group and a siloxane functional group or a silane functional group formed thereon. The coating body is formed by grafting the siloxane functional group or the silane functional group onto the surface of the substrate and bonding it to the substrate by covalent bonding.
[0018] The advantages of this invention are as follows: the hydrophilic coating contains the prepolymer, which can react with the hydrophilic lubricating material and the siloxane monomer to produce crosslinking and curing reactions, avoiding phase separation. This allows the hydrophilic coating to be directly and uniformly grafted onto the substrate surface through the siloxane functional groups or silane functional groups without the need for additional adhesives, resulting in good adhesion between the coating and the substrate. It also makes the hydrophobic substrate surface hydrophilic. Furthermore, since the hydrophilicity of the coating comes from its own hydrophilic functional groups, the hydrophilic effect of the coating will not decrease over time, exhibiting good stability. Simple Explanation of the Diagram
[0019] Figure 1 is a schematic diagram illustrating an embodiment of the hydrophilic coating of the present invention; and Figure 2 is a flowchart illustrating the method for manufacturing the hydrophilic coating. Implementation
[0020] The technical content and effects of this invention will be clearly presented in conjunction with the drawings and the following detailed description of the embodiments. It should be noted that the drawings are only used to illustrate the relative positions of the components and are not related to the actual dimensions of each component.
[0021] In one embodiment of the hydrophilic coating liquid of the present invention, a hydrophilic coating 20 as shown in FIG1 can be formed on the surface of a substrate 10, the substrate 10 being made of materials such as glass, ceramic, metal or plastic as required.
[0022] In this embodiment, the substrate 10 is described as being made of silicon material, but this is not a limitation. The silicon material itself is hydrophobic and has good chemical stability and heat resistance. The structure of the substrate 10 may vary depending on the actual needs. For example, the substrate 10 may be a silicon wafer, a silicon sample, a container, a petri dish, a clamping device, or other experimental or medical device, and is not limited to the drawings and the examples mentioned above.
[0023] The hydrophilic coating 20 is a single-layer structure comprising a coating body 21, at least a portion of which has a hydrophilic functional group and a siloxane functional group or a silane functional group formed on its surface. The coating body 21 is formed by directly grafting the siloxane functional group or the silane functional group onto the surface of the substrate 10, and is covalently bonded to the substrate 10, resulting in good adhesion between the coating body 21 and the substrate 10. In use, the hydrophilic coating 20 reacts with water molecules in the external environment, generating a hydrophilic interface structure on its surface, giving the surface of the hydrophilic coating 20 a wetting effect, further enhancing its biocompatibility, and simultaneously preventing experimental substances that come into contact with the hydrophilic interface structure from adhering to the hydrophilic coating 20.
[0024] In this embodiment, the coating body 21 is an interpenetrating polymer network (IPN) structure, which has good dimensional stability and good internal flexibility. Therefore, during repeated use of the substrate 10, the occurrence of peeling or cracking of the hydrophilic coating 20 due to repeated friction can be reduced. Furthermore, since the interpenetrating polymer network structure exhibits a continuous phase distribution, phase separation of the hydrophilic coating 20 is less likely to occur during the manufacturing process.
[0025] In this embodiment, the surface friction coefficient (COF) of the coating body 21 is not higher than 0.4. Therefore, when a substrate 10 with the hydrophilic coating 20 on its surface is used to carry an experimental substance that is a biological matrix, the hydrophilic coating 20 is not likely to damage the experimental substance, and the experimental substance is not likely to stick and cause pollution.
[0026] Preferably, the coefficient of friction of the surface of the coating body 21 is 0.35 to 0.38. More preferably, the coefficient of friction of the surface of the coating body 21 is not higher than 0.1.
[0027] The hydrophilic coating 20 is obtained by applying a hydrophilic coating liquid onto the substrate 10 and then subjecting it to a curing reaction. The hydrophilic coating liquid comprises a prepolymer, a silicate monomer, a hydrophilic lubricating material, a crosslinking agent, an initiator, and a solvent.
[0028] The prepolymer is obtained by polymerizing a functional monomer and a hydrophilic monomer, and the molar ratio of the functional monomer to the hydrophilic monomer is between 1:30 and 1:55. In this embodiment, the siloxane monomer and the functional monomer are selected from the same material. When the molar ratio of the functional monomer to the hydrophilic monomer is less than 1:30, the hydrophilic coating is prone to phase separation or the formation of lumps, resulting in decreased film-forming properties or uneven film formation in the subsequent process. When the molar ratio of the functional monomer to the hydrophilic monomer is greater than 1:55, the adhesion between the hydrophilic coating 20 and the substrate 10 will decrease.
[0029] In this embodiment, based on the total weight of the hydrophilic coating liquid, the content of the prepolymer is 2.5 wt% to 5.5 wt%, the content of the hydrophilic lubricating material is 5 wt% to 7 wt%, the content of the crosslinking agent is 2 wt% to 4 wt%, and the content of the initiator is 0.1 wt% to 1 wt%.
[0030] The siloxane monomer and the functional monomer are siloxane derivatives and have at least one active functional group, wherein the active functional group is selected from at least one of vinyl, propenyl, methacrylyl, phenyl, and epoxy groups. The siloxane monomer and the functional monomer may be selected from vinylsiloxane, allylsiloxane, methacryloxysiloxane, or vinylphenylsiloxane.
[0031] In other embodiments, the siloxane monomer and the functional monomer may also be selected from different siloxane derivatives as needed.
[0032] The hydrophilic monomer may be selected from at least one of N-vinylpyrrolidone (NVP), polyethylene glycol methacrylate (PEGMA), sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), 2-methacryloyloxyethylphosphorylcholine (MPC), acrylic acid (AA), 2-hydroxyethyl acrylate (HEA), maleic anhydride (MA), and functional compounds containing an amino group (-NH2).
[0033] The crosslinking agent is selected from acrylates or acrylamides, such as polyethylene glycol diacrylate (PEGDA), ethylene glycol dimethacrylate (EGDMA), trimethylolpropane triacrylate (TMPTA), and N,N'-methylenebisacrylamide (NMBA).
[0034] The hydrophilic lubricating material is hydrophilic and is selected from at least one of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), ethylene oxide (PEO), and hyaluronic acid (HA). The initiator is selected from α-hydroxy ketones, azo compounds, phosphine oxides, benzoyl peroxide, or ammonium persulfate. The solvent is a polar solvent and is selected from at least one of water, ethanol, and isopropanol.
[0035] In some embodiments, the hydrophilic coating may further include a thickener to increase viscosity, allowing the hydrophilic coating to more densely coat the substrate 10. The thickener is selected from carboxymethyl cellulose (CMC).
[0036] Referring to Figure 2, an embodiment of a method for fabricating the hydrophilic layer 20 is described, comprising the steps A to C.
[0037] Step A involves prepolymerizing the functional monomer and the hydrophilic monomer in a molar ratio between 1:30 and 1:55 to obtain the prepolymer.
[0038] Step B involves mixing the prepolymer, the silicate monomer, the hydrophilic lubricating material, the crosslinking agent, and the initiator in the solvent to prepare the hydrophilic coating.
[0039] Specifically, step B involves mixing the prepolymer, the siloxane monomer, and the initiator in a first solvent to prepare a first solution; mixing the crosslinking agent and the hydrophilic lubricating material in a second solvent to prepare a second solution; and then mixing the first solution and the second solution to obtain the hydrophilic coating liquid, wherein the first solvent and the second solvent may be the same or different.
[0040] Step C involves applying the hydrophilic coating to the surface of the substrate 10 and then curing the hydrophilic coating on the surface of the substrate 10 by photocuring or thermal curing to obtain the hydrophilic coating 20 covering the surface of the substrate 10. In this embodiment, the substrate 10 is made of silicon material, but it is not limited to this.
[0041] During the curing process, the siloxane functional group or silane functional group of the hydrophilic coating 20 will form a bond with the hydroxyl group on the surface of the substrate 10 and be grafted onto the surface of the substrate 10, so that the hydrophilic coating 20 and the substrate 10 have good adhesion and are tightly attached to the surface of the substrate 10.
[0042] In detail, because the siloxane functional groups or silane functional groups of the siloxane monomer are hydrophobic, direct mixing with the hydrophilic lubricating material can easily lead to phase separation, resulting in structural inhomogeneity or insufficient film formation during subsequent polymer solution film formation. Therefore, the manufacturing method of this embodiment prepolymerizes the functional monomer and the hydrophilic monomer (which are homologous materials to the siloxane monomer) in step A to form a prepolymer. Then, in step B, the first solution containing the prepolymer and the siloxane monomer is mixed with the second solution containing the hydrophilic lubricating material. Through the interaction of the prepolymer with the siloxane monomer and the hydrophilic lubricating material respectively, phase separation problems can be avoided during the process, and the formation of the interpenetrating polymer network (IPN structure) can be promoted. In step C, the siloxane functional group or silane functional group of the functional monomer and the siloxane monomer can serve as anchor points, allowing the hydrophilic coating 20 to be directly grafted onto the surface of the substrate 10 made of silica material without being easily peeled off, and exhibiting good hydrophilicity. At the same time, the IPN structure can make the hydrophilic coating 20 exhibit good flexibility and a low coefficient of friction.
[0043] In some other embodiments, the substrate 10 may also be selected from glass, ceramic, metal or plastic, and the functional monomer and the siloxane functional group or silane functional group of the siloxane monomer may be grafted onto the substrate 10 as anchor points and closely adhered to the hydrophilic coating 20.
[0044] By using the hydrophilic coating liquid containing the prepolymer to form the hydrophilic coating 20, not only is it less likely for the solution to undergo phase separation during the process, thereby improving the process yield, but the hydrophilic effect of the formed hydrophilic coating 20 comes from the hydrophilic functional groups and will not disappear over time, thus extending the product's service life.
[0045] Referring again to Figures 1 and 2, the hydrophilic coating 20 prepared by the aforementioned method is described in the following specific examples 1 and 2. A friction test, a roughness test, and an adhesion test were performed on the hydrophilic coatings of these specific examples 1 and 2, and the results are summarized in Table 1.
[0046] The friction test was performed using a coefficient of friction tester (manufacturer: SHIMADZU, model: ASG-X), and the testing process conformed to the ASTM D1894 inspection standard. The roughness test was performed using a roughness measuring instrument (manufacturer: FSM, model: Nanoview 1000). After the friction test, the adhesion test was performed in a water bath environment, with the temperature of the water bath environment controlled between 36°C and 37.5°C to simulate the body temperature of the human body. During the test, a silicone clamp was used to clamp the substrate 10 with a clamping force not exceeding 500 g, and a tensile force orthogonal to the clamping direction was applied, so that the silicone clamp repeatedly rubbed the hydrophilic coating 20 to observe the change in its surface friction coefficient.
[0047] Specific example 1
[0048] First, step A is performed, in which 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) and 2-hydroxyethyl acrylate (HEA) are prepolymerized at a molar ratio of 1:50 to form a prepolymer. Then, step B is performed.
[0049] In step B, the prepolymer, trimethoxysilyl methacrylate (TMSPMA), and azobisisobutyronitrile (AIBN) are mixed in ethanol to prepare a first solution; polyvinylpyrrolidone (PVP) and polyethylene glycol diacrylate (PEGDA) are mixed in ethanol to prepare a second solution; then, the first solution and the second solution are mixed to obtain a hydrophilic coating. The component ratios of the hydrophilic coating are shown in Table 1.
[0050] Next, step C is performed, in which a hydrophilic coating is applied to the surface of a substrate 10 by means of coating (e.g., spin coating or spray coating), and heated at a temperature of 100°C to cause the hydrophilic coating to undergo a cross-linking and curing reaction, forming a hydrophilic coating 20. The thickness of the hydrophilic coating 20 is 6.5 μm, and according to the results of the friction test and the roughness test, the coefficient of friction (COF) of the hydrophilic coating 20 in Example 1 is 0.376, and the average roughness (RA) is 4.83 nm. Then, an adhesion test is performed, in which the hydrophilic coating 20 of Example 1 is repeatedly rubbed using a silicone jig. After more than 10 repeated rubbing cycles, the hydrophilic coating 20 did not peel off, and its coefficient of friction did not change significantly (the difference in COF was not higher than 0.015).
[0051] Specific example 2
[0052] The preparation method of Example 2 is largely the same as that of Example 1, except that the crosslinking agent in Example 2 is trimethylolpropane triacrylate (TMPTA). The hydrophilic coating 20 of Example 2 has a thickness of 4.7 μm, a coefficient of friction (COF) of 0.091, and an average roughness (RA) of 4.01 nm. Subsequently, an adhesion test was performed, in which the hydrophilic coating 20 of Example 1 was repeatedly rubbed using a silicone fixture. After more than 10 cycles of repeated rubbing, the hydrophilic coating 20 did not peel off, and its coefficient of friction did not change significantly (the difference in COF was no greater than 0.012).
[0053] Table 1. Specific Example 1. Specific Example 2. First Solution: Silicon Oxide Monomer TMSPMA 1.5 wt% TMSPMA 1.5 wt% Prepolymer TMSPMA-HEA 3.3 wt% TMSPMA-HEA 3.3 wt% Initiator AIBN 0.1 wt% AIBN 0.1 wt% First Solvent: Ethanol 48.4 wt% Ethanol 48.4 wt% Second Solution: Hydrophilic Lubricating Material PVP 6.65 wt% PVP 6.65 wt% Crosslinking Agent PEGDA 2.65 wt% TMPTA 2.65 wt% Second Solvent: Ethanol 37.4 wt% Ethanol 37.4 wt% Test Results: Coefficient of Friction (COF) 0.376 0.091 Roughness (nm) 4.83 4.01
[0054] When the hydrophilic coating 20 of these specific examples 1 and 2 is subjected to the adhesion test, it can be found that no peeling occurs even after repeated rubbing on its surface, and its coefficient of friction does not change significantly. It is evident that the hydrophilic coating 20 prepared by the method of this embodiment has sufficiently good adhesion to the substrate 10, is not easy to peel off, and also has good durability.
[0055] Furthermore, compared to the original surface of the substrate 10, which has a coefficient of friction of approximately 1.84, after the formation of the hydrophilic coating 20, the coefficient of friction of the surface of the hydrophilic coating 20 in Example 1 is 0.376, and the coefficient of friction of the surface of the hydrophilic coating 20 in Example 2 is 0.091, representing a decrease of at least 80%. Therefore, the hydrophilic coating 20 not only makes the surface of the substrate 10 hydrophilic but also reduces surface friction, thus preventing the carried material from adhering to the substrate 10. The hydrophilic coatings 20 in Examples 1 and 2 exhibit good lubricating properties.
[0056] In summary, the hydrophilic coating of the present invention contains the prepolymer, which can react with the hydrophilic lubricating material and the siloxane monomer to produce a cross-linking curing reaction, avoiding phase separation. This allows the hydrophilic coating 20 to simultaneously possess both hydrophilic functional groups and siloxane or silane functional groups. Therefore, without the need for additional adhesives, the hydrophilic coating 20 can be uniformly and directly grafted onto the surface of the substrate 10, exhibiting good adhesion. Furthermore, since the hydrophilic properties of the hydrophilic coating 20 originate from its own hydrophilic functional groups, the hydrophilic effect of the hydrophilic coating 20 will not decrease over time, exhibiting good stability. Thus, the purpose of the present invention is indeed achieved.
[0057] 10: Substrate 20: Hydrophilic coating 21: Coating Body A~C: Steps
Claims
1. A hydrophilic coating liquid, comprising: a silicate monomer, a prepolymer, a hydrophilic lubricating material, a crosslinking agent, an initiator, and a solvent, wherein the prepolymer is obtained by polymerizing a functional monomer and a hydrophilic monomer, the molar ratio of the functional monomer to the hydrophilic monomer being between 1:30 and 1:55, wherein, The hydrophilic lubricating material is selected from at least one of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and hyaluronic acid (HA). The siloxane monomer and the functional monomer are siloxane derivatives and have at least one active functional group, which is selected from at least one of vinyl, propylene, methpropylene, phenyl, and epoxy groups. The crosslinking agent is selected from acrylate or acrylamide.
2. The hydrophilic coating as described in claim 1, wherein, The content of the prepolymer is 2.5 wt% to 5.5 wt% based on the total weight of the hydrophilic coating liquid, the content of the hydrophilic lubricating material is 5 wt% to 7 wt%, the content of the crosslinking agent is 2 wt% to 4 wt%, and the content of the initiator is 0.1 wt% to 1 wt%.
3. The hydrophilic coating as described in claim 1, wherein, The hydrophilic monomer is selected from at least one of N-vinylpyrrolidone (NVP), polyethylene glycol methacrylate (PEGMA), sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), 2-methacryloyloxyethylphosphorylcholine (MPC), acrylic acid (AA), 2-hydroxyethyl acrylate (HEA), maleic anhydride (MA), and a functional compound containing an amino group. The solvent is a polar solvent selected from at least one of water, ethanol, and isopropanol. The initiator is selected from α-hydroxy ketones, azo compounds, phosphine oxides, benzoyl peroxide, or ammonium persulfate.
4. A method for preparing a hydrophilic coating, applicable to the hydrophilic coating liquid as described in any one of claims 1 to 3, comprising: Step A, prepolymerizing a functional monomer and a hydrophilic monomer to obtain a prepolymer, wherein the molar ratio of the functional monomer to the hydrophilic monomer is between 1:30 and 1:55; Step B, mixing the prepolymer, a silicate monomer, a hydrophilic lubricating material, a crosslinking agent, and an initiator in a solvent to prepare the hydrophilic coating liquid; and Step C, applying the hydrophilic coating liquid to the surface of a substrate, and curing the hydrophilic coating liquid by photocuring or thermocuring to obtain a hydrophilic coating covering the surface of the substrate, wherein... The hydrophilic coating is a single-layer structure, with at least a portion of its surface having a hydrophilic functional group and a siloxane functional group or a silane functional group. The hydrophilic coating is formed by grafting the siloxane functional group or the silane functional group onto the surface of the substrate.
5. The method for preparing the hydrophilic coating as described in claim 4, wherein, Step B involves mixing the prepolymer, the siloxane monomer, and the initiator in a first solvent to prepare a first solution, mixing the crosslinking agent and the hydrophilic lubricating material in a second solvent to prepare a second solution, and mixing the first solution and the second solution to obtain the hydrophilic coating liquid. The first solvent and the second solvent may be the same or different.
6. A hydrophilic coating, obtained by applying a hydrophilic coating liquid to a substrate and curing it, the hydrophilic coating comprising: a coating body having a single-layer structure, and at least a portion of its surface having a hydrophilic functional group, and a siloxane functional group or a silane functional group, wherein, The coating body is formed by grafting the siloxane functional group or silane functional group onto the surface of the substrate and bonding it to the substrate in a covalent manner. in, A hydrophilic coating liquid comprises: a silicate monomer, a prepolymer, a hydrophilic lubricating material, a crosslinking agent, an initiator, and a solvent. The prepolymer is obtained by polymerizing a functional monomer and a hydrophilic monomer, wherein the molar ratio of the functional monomer to the hydrophilic monomer is between 1:30 and 1:
55. The hydrophilic lubricating material is selected from at least one of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and hyaluronic acid (HA). The silicate monomer and the functional monomer are silicate derivatives and have at least one active functional group, wherein the active functional group is selected from at least one of vinyl, acrylyl, methacrylic, phenyl, and epoxy groups. The crosslinking agent is selected from acrylate or acrylamide.
7. The hydrophilic coating as described in claim 6, wherein, The coefficient of friction of the surface of the hydrophilic coating is no higher than 0.
4.
8. The hydrophilic coating as described in claim 6, wherein, The hydrophilic coating is an interpenetrating polymer network structure.
9. The hydrophilic coating as described in claim 6, wherein, This hydrophilic coating can react with water molecules to form a hydrophilic interface structure.