Hydrophilic membranes, methods of making and products thereof

Abstract

Embodiments of the present disclosure provide a hydrophilic film, a method of manufacturing the same, and a product, the hydrophilic film being a plasma polymerized film formed by plasma deposition of an organic silicon monomer and a gas including an oxidizing gas on at least a part of a surface of a substrate under plasma excitation, or the hydrophilic film being a plasma polymerized hydrolyzed film formed by hydrolysis of the plasma polymerized film, the hydrophilic film having good hydrophilicity and light transmittance.

Description

Technical Field

[0001] This disclosure relates to the field of membrane technology, and in particular to a hydrophilic membrane and its preparation method and product. Background Technology

[0002] Wettability, as one of the fundamental properties of material surfaces, plays a vital role in production and daily life. Improving the wettability of substrates through hydrophilic modification can avoid or mitigate the negative effects of non-wetting in many applications and also expand new hydrophilic applications. For example, to prevent fogging in optical observation windows such as eyeglasses, automotive glass, and camera lenses, hydrophilic modification can be performed, allowing water vapor in the air to form a uniform water film on the surface of the cold substrate, with almost no impact on the original light transmittance. To maintain the cleanliness of photovoltaic glass covers and high-rise building glass, hydrophilic modification allows water rinsing to remove dust and other stains, maintaining self-cleaning properties. Furthermore, in the biomedical field, hydrophilic modification can be applied to the surfaces of medical devices to reduce biological pain caused by interventional catheter treatments.

[0003] There are various types of hydrophilic modified materials, one of which uses silicon as the material to prepare hydrophilic surfaces. Patent CN116179041A discloses a method for preparing a hydrophilic coating. First, hollow silica microspheres are prepared by mixing, aging, and calcining sodium silicate, graphene oxide, solvent, urea, and styrene-acrylic emulsion. Then, the hollow silica microspheres, vinyltrimethoxysilane, tetraethyl orthosilicate, and solvent are mixed and reacted to obtain modified hollow microspheres. Next, the modified hollow microspheres, 4,3',5'-trihydroxyresveratrol, butyl acrylate, and solvent are mixed, and azobisisobutyronitrile is added to react and obtain a block polymer. Finally, the block polymer, pentylene glycol diacrylate, initiator, and solvent are mixed to obtain a spraying liquid. The spraying liquid is sprayed onto the substrate surface and cured to obtain a hydrophilic coating with a water contact angle of less than 10 degrees. However, this preparation process is very cumbersome, with a calcination temperature reaching 480℃ and a long thermal curing time.

[0004] Patent CN116102977A discloses a transparent hydrophilic antifog coating and its preparation method using silicon-doped carbonized polymer dots as building blocks. First, a polyamino oligomeric siloxane (MAOS) is prepared via a hydrothermal method using 3-aminopropyltriethoxysilane as a raw material and tetramethylammonium hydroxide as a catalyst. This MAOS is then reacted with ethylenediaminetetraacetic acid (EDTA) to prepare Si-CPDs. Next, ethylene oxide, γ-glycidyl etheroxypropyltrimethoxysilane (GPTMS), a curing agent, and a leveling agent are added. The cured coating solution is then applied to a substrate, and after thermal curing, a Si-O-Si cross-linked network structure is formed, resulting in a transparent hydrophilic antifog coating. The resulting hydrophilic coating has a water contact angle of 53°, which is relatively large compared to typical hydrophilic coatings and may not meet the requirements of applications with higher hydrophilicity requirements.

[0005] Therefore, a new type of hydrophilic membrane needs to be developed. Summary of the Invention

[0006] Embodiments of this disclosure provide a hydrophilic membrane, which is a plasma-polymerized membrane formed by depositing an organosilicon monomer and a gas including an oxidizing gas on at least a portion of the surface of a substrate under plasma excitation, or the hydrophilic membrane is a plasma-polymerized hydrolyzed membrane formed by hydrolyzing the plasma-polymerized membrane; wherein the organosilicon monomer has the structure shown in formula (1) or formula (2).

[0007]

[0008] In formula (1), R1, R2, and R3 are independently selected from: hydrogen atom, halogen atom, C1-C8 hydrocarbon group, C1-C8 hydroxyl group, C1-C8 hydrocarbon group with hydrophilic substituent, C1-C8 hydroxyl group with hydrophilic substituent, or C1-C containing at least one heteroatom in the chain. 20 R4 is selected from hydrogen atom, C1-C8 hydrocarbon group or C1-C8 alkyl acyl group; n is an integer from 1 to 50; in formula (2), R5 is selected from: hydrogen atom, halogen atom, C1-C8 hydrocarbon group, C1-C8 alkyloxy group, C1-C8 hydrocarbon group with hydrophilic substituent, C1-C8 alkyloxy group with hydrophilic substituent, or C1-C containing at least one heteroatom in the chain. 20 The hydrocarbon group; R6 is selected from C1-C8 hydrocarbon oxy groups or C1-C8 hydrocarbon acyl oxy groups; m is an integer from 3 to 10.

[0009] In some embodiments, the hydrophilic substituent comprises one or more of the following: hydroxyl, amino, carboxyl, amine, ether, or sulfonic acid groups.

[0010] In some embodiments, the hydrophilic substituent has the structure shown in formula (3).

[0011]

[0012] In formula (3), X is selected from hydrogen atom, hydroxyl, amino, carboxyl or sulfonic acid group; Y is selected from linking bond, ether or amino group; Z is selected from linking bond or C1-C8 alkylene group; wherein, when X is hydrogen atom, Y is not linking bond; a is an integer from 1 to 4, and b is an integer from 1 to 4.

[0013] In some embodiments, n is 1, R1 is a hydrogen atom, a C1-C4 hydrocarbon group, a C1-C4 hydrocarbon group with a hydrophilic substituent, or a C1-C4 hydroxyl group, R2 is a hydrogen atom, a C1-C4 hydrocarbon group, or a C1-C4 hydroxyl group, R3 is a C1-C4 hydroxyl group or a C1-C4 hydrocarbon group, and R4 is a C1-C4 hydrocarbon group.

[0014] In some embodiments, R5 is a hydrogen atom, a C1-C4 hydrocarbon group, a C1-C4 hydrocarbon group with a hydrophilic substituent, or a C1-C4 hydroxyl group, and R6 is a C1-C4 hydroxyl group.

[0015] In some embodiments, the organosilicon monomer is selected from one or more of the following: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutyl silicate, tetraisopropyl orthosilicate, tetra(isopropoxy)silane, methyltripropoxysilane, triethoxysilane, methyltriethoxysilane, dimethoxydimethylsilane, di-tert-butoxydimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, diethylenetriaminopropyltrimethoxysilane, and 3-aminopropylmethyldimethoxysilane.

[0016] In some embodiments, the oxidizing gas includes one or more of oxygen, nitrogen dioxide, ozone, hydrogen peroxide, and carbon dioxide.

[0017] In some embodiments, the water contact angle of the hydrophilic membrane is not greater than 8°.

[0018] In some embodiments, the hydrophilic film is formed by hydrolysis after deposition of a substrate containing the organosilicon monomer in an atmosphere of oxidizing gas.

[0019] In some embodiments, after the hydrophilic membrane is immersed in deionized water for 10 minutes, the water contact angle of the hydrophilic membrane is no greater than 30°.

[0020] In some embodiments, the plasma-polymerized hydrolyzed membrane is placed in a room temperature environment, and the placement time is more than 1 day when the water contact angle of the plasma-polymerized hydrolyzed membrane is greater than 10°.

[0021] The embodiments of this disclosure also provide a method for preparing a hydrophilic membrane, for preparing any of the above-mentioned hydrophilic membranes. The preparation method includes: introducing the organosilicon monomer and a gas including an oxidizing gas into a cavity containing a substrate, and activating plasma discharge to perform plasma deposition on at least a portion of the surface of the substrate to form a plasma polymerized membrane.

[0022] In some embodiments, the preparation method further includes: hydrolyzing the plasma polymerized membrane to form the plasma polymerized hydrolyzed membrane.

[0023] In some embodiments, the hydrolysis includes contacting the plasma polymerized membrane with an alkaline solution of pH 8 to 14 to perform hydrolysis.

[0024] In some embodiments, the hydrolysis further includes: contacting the plasma-polymerized membrane formed on the substrate with an alkaline solution of pH 9 to 12 and immersing it at a temperature of 40°C to 100°C for more than 2 hours, thereby forming the plasma-polymerized hydrolyzed membrane on the substrate.

[0025] In some embodiments, the plasma deposition includes: introducing vapor including the organosilicon monomer into a reaction chamber, introducing oxygen, maintaining a vacuum of 10 to 200 mTorr in the reaction chamber, and activating plasma discharge to deposit a film on the substrate.

[0026] In some embodiments, before introducing the vapor comprising the organosilicon monomer into the reaction chamber, the substrate is provided and placed in the reaction chamber, the vacuum is evacuated to 10-200 mTorr, one or more of helium, argon or oxygen are introduced, and plasma discharge is activated to activate the substrate.

[0027] In some embodiments, the discharge power of the plasma discharge is 100W to 1000W; during the coating process, a pulse bias voltage is applied to the support frame supporting the substrate, the pulse bias voltage is 100V to 1000V, the pulse frequency is 10Hz to 300kHz, the pulse duty cycle is 5% to 80%, and the plasma discharge time is 100s to 36000s.

[0028] In some embodiments, the plasma discharge is performed via ICP discharge, wherein the ICP discharge power is 500W to 1000W.

[0029] In some embodiments, the substrate is glass.

[0030] Embodiments of this disclosure also provide a product having at least a portion of its surface covered with any of the hydrophilic films described above.

[0031] In some embodiments, the product is a transparent product, and the transmittance of the product is above 96% as measured by a UV-Vis spectrophotometer.

[0032] Compared with the prior art, the technical solutions of the embodiments of this disclosure have the following beneficial effects:

[0033] The hydrophilic membrane of the present disclosure is a plasma polymerized membrane formed by depositing an organosilicon monomer and a gas including an oxidizing gas on at least a portion of the surface of a substrate under plasma excitation, and the hydrophilic membrane has good hydrophilicity.

[0034] Furthermore, the hydrophilic membrane is a plasma-polymerized hydrolyzed membrane formed by hydrolysis of the plasma-polymerized membrane. The plasma-polymerized hydrolyzed membrane has good hydrophilicity and stable and durable hydrophilic properties.

[0035] The method for preparing a hydrophilic membrane according to embodiments of this disclosure involves plasma deposition of an organosilicon monomer and a gas including an oxidizing gas on at least a portion of the surface of a substrate under plasma discharge to form a plasma polymeric membrane, wherein the plasma polymeric membrane has good hydrophilicity.

[0036] Furthermore, the plasma polymer membrane is hydrolyzed, and the resulting plasma polymer hydrolyzed membrane exhibits good hydrophilicity and hydrophilic durability.

[0037] At least a portion of the surface of the product in the embodiments of this disclosure has a hydrophilic film with good hydrophilicity and transparency. The light transmittance of the hydrophilic film is above 96%. When the product is a transparent product, the hydrophilic film does not affect the overall transmittance of the product. Detailed Implementation

[0038] Siloxane monomers are commonly used in plasma deposition to prepare hydrophobic films. The inventors have discovered that, through monomer selection and process design, hydrophilic films can be prepared by plasma deposition of organosilicon monomers containing hydrolyzable groups. These hydrophilic films exhibit good hydrophilicity, hydrophilic durability, and good light transmittance. The specific embodiments of this disclosure are described in detail below.

[0039] A specific embodiment of this disclosure provides a hydrophilic membrane, which is a plasma-polymerized membrane formed by depositing an organosilicon monomer and a gas including an oxidizing gas on at least a portion of the surface of a substrate under plasma excitation, or the hydrophilic membrane is a plasma-polymerized hydrolyzed membrane formed after hydrolysis of the plasma-polymerized membrane; wherein the organosilicon monomer has the structure shown in formula (1) or formula (2).

[0040]

[0041] In formula (1), R1, R2, and R3 are independently selected from: hydrogen atom, halogen atom, C1-C8 hydrocarbon group, C1-C8 hydroxyl group, C1-C8 hydrocarbon group with hydrophilic substituent, C1-C8 hydroxyl group with hydrophilic substituent, or C1-C containing at least one heteroatom in the chain. 20The hydrocarbon group. In some specific embodiments, among the C1-C8 hydrocarbon group and the C1-C8 hydrocarbon group having a hydrophilic substituent, the hydrocarbon group can be alkyl, alkenyl, or alkynyl, and the hydrocarbon group can be a straight-chain hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group. In some specific embodiments, among the C1-C8 alkyloxy group and the C1-C8 alkyloxy group having a hydrophilic substituent, the alkyloxy group can be alkoxy, alkenyloxy, or alkynyloxy, and the alkyloxy group can be a straight-chain alkyloxy group, a branched alkyloxy group, or a cyclic alkyloxy group. In some specific embodiments, the C1-C8 group containing at least one heteroatom in the chain... 20 The heteroatom in the hydrocarbon group can be one or more of oxygen, nitrogen, or sulfur atoms; in some specific embodiments, the C1-C group containing at least one heteroatom in the chain... 20 The hydrocarbon group may also contain non-chain heteroatoms. In some specific embodiments, R1, R2, and R3 are each independently selected from C1-C6 hydrocarbon groups containing at least one chain heteroatom, such as -CH2OCH3, -CH2NHCH3, -CH2SCH3, -CH2CH2NHCH2CH2NHCH2CH3, -CH2CH2OCH2CH2NHCH2CH3, -CH2CH2OCH2CH2SCH2CH3, -CH2CH2SCH2CH2NHCH2CH3, -CH2CH2OCH2CH2OCH2CH2CH3, etc.

[0042] R4 is selected from hydrogen atoms, C1-C8 hydrocarbon groups, or C1-C8 hydrocarbon acyl groups; in some specific embodiments, among the C1-C8 hydrocarbon groups and C1-C8 hydrocarbon acyl groups, the hydrocarbon group connected to the acyl group can be alkyl, alkenyl, or alkynyl, and the hydrocarbon group connected to the acyl group can be a straight-chain hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group.

[0043] In equation (1), n ​​is an integer from 1 to 50; in some specific embodiments, n is an integer from 1 to 10; in some specific embodiments, n is 1, 2, 3, 4 or 5.

[0044] In some specific embodiments of the hydrophilic membrane disclosed herein, in formula (1), n ​​is 1, and R1 is a hydrogen atom, a C1-C4 hydrocarbon group, a C1-C4 hydrocarbon group with hydrophilic substituents, or a C1-C4 hydroxyl group. The hydrocarbon group and hydroxyl group can be straight-chain, branched, or have a cyclic structure. The C1-C4 hydrocarbon group can be a C1-C4 alkyl, alkenyl, or alkynyl group; the C1-C4 hydroxyl group can be a C1-C4 alkoxy, alkenyloxy, or alkynyloxy group. It should be noted that for C1-C4 hydrocarbon groups with hydrophilic substituents, C1-C4 only indicates that the number of carbon atoms in the hydrocarbon group itself is 1 to 4, excluding the number of carbon atoms in the hydrophilic substituents. The number of carbon atoms in the hydrophilic substituents is not limited here.

[0045] In some specific embodiments, in formula (1), n ​​is 1, and R2 is a hydrogen atom, a C1-C4 hydrocarbon group, or a C1-C4 alkyloxy group. The hydrocarbon group and alkyloxy group can be straight-chain, branched, or have a cyclic structure. The C1-C4 hydrocarbon group can be a C1-C4 alkyl, alkenyl, or alkynyl group; the C1-C4 alkyloxy group can be a C1-C4 alkoxy, alkenyloxy, or alkynyloxy group.

[0046] In some specific embodiments, in formula (1), n ​​is 1, and R3 is a C1-C4 alkyl group or a C1-C4 hydrocarbon group. The hydrocarbon group and alkyl group can be straight-chain, branched, or have a cyclic structure. The C1-C4 hydrocarbon group can be a C1-C4 alkyl, alkenyl, or alkynyl group; the C1-C4 alkyl group can be a C1-C4 alkoxy, alkenyl, or alkynyl group.

[0047] In some specific embodiments, in formula (1), n ​​is 1, and R4 is a C1-C4 hydrocarbon group, which may be a straight chain, a branched chain, or a ring structure; in some specific embodiments, R4 is a C1-C4 alkyl, alkenyl, or alkynyl group.

[0048] In some embodiments of the hydrophilic membrane disclosed herein, the organosilicon monomer has the structure of formula (1), wherein n is 1, R1 is a C1-C4 alkenyl, C1-C4 alkoxy, or C1-C4 alkyl with a hydrophilic substituent, R2 is a C1-C4 alkyl or C1-C4 alkoxy, R3 is a C1-C4 alkoxy, and R4 is a C1-C4 alkyl. In some embodiments, R1 is a C1-C4 alkyl with a hydrophilic substituent, wherein the hydrophilic substituent is an amino, hydroxyl, or carboxyl group.

[0049] In some specific embodiments, the organosilicon monomer is selected from one or more of the following: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutyl silicate, tetraisopropyl orthosilicate, tetra(isopropoxy)silane, methyltripropoxysilane, triethoxysilane, methyltriethoxysilane, dimethoxydimethylsilane, di-tert-butoxydimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, diethylenetriaminopropyltrimethoxysilane, and 3-aminopropylmethyldimethoxysilane.

[0050] In some specific embodiments, the organosilicon monomer is selected from one or more of vinyltrimethoxysilane, vinyltriethoxysilane, dimethyldimethoxysilane, or 3-aminopropylmethyldimethoxysilane.

[0051] In the hydrophilic membrane of a specific embodiment of this disclosure, in formula (2), R5 is selected from: hydrogen atom, halogen atom, C1-C8 hydrocarbon group, C1-C8 hydroxyl group, C1-C8 hydrocarbon group having hydrophilic substituent, C1-C8 hydroxyl group having hydrophilic substituent, or C1-C containing at least one heteroatom in the chain. 20 The hydrocarbon group. In some specific embodiments, among the C1-C8 hydrocarbon group and the C1-C8 hydrocarbon group having a hydrophilic substituent, the hydrocarbon group can be alkyl, alkenyl, or alkynyl, and the hydrocarbon group can be a straight-chain hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group. In some specific embodiments, among the C1-C8 alkyloxy group and the C1-C8 alkyloxy group having a hydrophilic substituent, the alkyloxy group can be alkoxy, alkenyloxy, or alkynyloxy, and the alkyloxy group can be a straight-chain alkyloxy group, a branched alkyloxy group, or a cyclic alkyloxy group. In some specific embodiments, the C1-C8 group containing at least one heteroatom in the chain... 20 The heteroatom in the hydrocarbon group can be one or more of oxygen, nitrogen, and sulfur atoms; in some specific embodiments, the C1-C group containing at least one heteroatom in the chain... 20 The hydrocarbon group may also contain non-chain heteroatoms. In some specific embodiments, R5 is selected from C1-C6 hydrocarbon groups containing at least one chain heteroatom, such as -CH2OCH3, -CH2NHCH3, -CH2SCH3, -CH2CH2NHCH2CH2NHCH2CH3, -CH2CH2OCH2CH2NHCH2CH3, -CH2CH2OCH2CH2SCH2CH3, -CH2CH2SCH2CH2NHCH2CH3, -CH2CH2OCH2CH2OCH2CH2CH3, etc.

[0052] R6 is selected from C1-C8 alkyloxy groups or C1-C8 alkylacyloxy groups; in some specific embodiments, among the C1-C8 alkyl groups and C1-C8 alkylacyl groups, the alkyl group connected to the acyl group can be alkyl, alkenyl or alkynyl, and the alkyl group connected to the acyl group can be a straight-chain alkyl group, a branched alkyl group or a cyclic alkyl group.

[0053] In equation (2), m is an integer from 3 to 10; in some specific implementations, m is 3, 4, 5 or 6.

[0054] In some specific embodiments of the hydrophilic membrane disclosed herein, in formula (2), R5 is a hydrogen atom, a C1-C4 hydrocarbon group, a C1-C4 hydrocarbon group with hydrophilic substituents, or a C1-C4 alkoxy group, and R6 is a C1-C4 alkoxy group. Specifically, the C1-C4 hydrocarbon group and the C1-C4 alkoxy group can be straight-chain, branched, or have a cyclic structure. The C1-C4 hydrocarbon group can be a C1-C4 alkyl, alkenyl, or alkynyl group; the C1-C4 alkoxy group can be a C1-C4 alkoxy, alkenyl, or alkynyl group. In some specific embodiments, R5 is a hydrogen atom, a C1-C4 alkyl group, a C1-C4 alkyl group with hydrophilic substituents, or a C1-C4 alkoxy group, and R6 is a C1-C4 alkoxy group.

[0055] In some embodiments of the hydrophilic membrane disclosed herein, the organosilicon monomer has hydrophilic substituents, such as the hydrophilic substituents in the structures of formulas (1) and (2), thereby further enhancing the hydrophilicity of the hydrophilic membrane.

[0056] In some specific embodiments, the hydrophilic substituent has the structure shown in formula (3).

[0057]

[0058] In formula (3), X is selected from hydrogen atom, hydroxyl, amino, carboxyl or sulfonic acid group; Y is selected from linking bond, ether group or amino group, wherein the ether group can be a monoether group or a mixed ether group, and the amino group can be a substituted or unsubstituted amino group; Z is selected from linking bond or C1-C8 alkylene group; wherein, when X is hydrogen atom, Y is not linking bond.

[0059] In equation (3), a is an integer from 1 to 4, and b is an integer from 1 to 4.

[0060] In some specific embodiments, the hydrophilic substituent comprises one or more of the following: hydroxyl, amino, carboxyl, amine, ether, or sulfonic acid groups.

[0061] The hydrophilic membrane of the specific embodiments of this disclosure includes an oxidizing gas, which means that the gas can be an oxidizing gas alone or a mixture of oxidizing gas and other gases. In some specific embodiments, the other gases include, but are not limited to, one or more of nitrogen, helium, argon and neon.

[0062] In some specific embodiments, the oxidizing gas includes, but is not limited to, one or more of oxygen, nitrogen dioxide, ozone, hydrogen peroxide, and carbon dioxide; in some specific embodiments, the oxidizing gas is oxygen.

[0063] In some specific embodiments, the hydrophilic membrane of this disclosure is a plasma-polymerized hydrolyzed membrane formed by hydrolysis of the plasma-polymerized membrane. The plasma-polymerized hydrolyzed membrane possesses good hydrophilic properties, hydrophilic durability, and light transmittance. Since the plasma-polymerized membrane formed by plasma deposition of the organosilicon monomer has hydrolyzable groups, further hydrolysis is beneficial for increasing the hydrophilic durability of the membrane layer.

[0064] In some specific embodiments, the water contact angle of the hydrophilic membrane in the specific embodiments of this disclosure is no greater than 8°.

[0065] In some specific embodiments, after immersing the hydrophilic membrane of the present disclosure in deionized water for 10 minutes, the water contact angle of the hydrophilic membrane is not greater than 30°; in some specific embodiments, it is not greater than 20°; in some specific embodiments, it is not greater than 15°.

[0066] In some specific embodiments, the hydrophilic membrane of the present disclosure is placed in a room temperature environment, and the water contact angle of the hydrophilic membrane is greater than 10° for more than 1 day; in some specific embodiments, it is placed for more than 10 days.

[0067] In some specific embodiments, the hydrophilic membrane of the present disclosure has a permeability of over 96%.

[0068] The specific embodiments of this disclosure also provide a method for preparing a hydrophilic membrane, which is used to prepare any of the above-mentioned hydrophilic membranes. The preparation method includes: introducing the organosilicon monomer and a gas including an oxidizing gas into a cavity containing a substrate, and activating plasma discharge to perform plasma deposition on at least a portion of the surface of the substrate to form a plasma polymerized membrane.

[0069] The preparation method of this disclosure, in some specific embodiments, involves forming the plasma polymerized film by: introducing vapor including an organosilicon monomer into a reaction chamber, introducing oxygen, maintaining a vacuum of 10–200 mTorr in the reaction chamber, and activating plasma discharge to deposit a film on the substrate. The organosilicon monomer is the same as that in any of the above embodiments and will not be described again here.

[0070] The preparation method of the specific embodiments disclosed herein involves plasma excitation to carry out plasma polymerization of organosilicon monomers at low temperature, and by adjusting the plasma polymerization process parameters, a dense and uniform hydrophilic film is formed on the substrate.

[0071] The preparation method of this disclosure, in which oxygen is introduced, facilitates the formation of hydroxyl groups on the polymer generated by plasma polymerization of organosilicon monomers, thereby improving the hydrophilicity of the hydrophilic membrane. By adjusting the amount of vapor including organosilicon monomers and the amount of oxygen introduced, the plasma polymerization reaction can be controlled more precisely. In some specific embodiments, the flow rate of vapor including organosilicon monomers is 50-1000 μL / min, and the flow rate of oxygen is 50-500 sccm.

[0072] In some specific embodiments of the preparation method disclosed herein, the plasma discharge is ICP (inductively coupled plasma) discharge, and the discharge mode is continuous discharge or pulsed discharge. The discharge power is 100-1000W, specifically, for example: 100W, 200W, 300W, 400W, 500W, 600W, 700W, 800W, 900W, or 1000W, etc. The discharge time is 60-36000s, specifically, for example: 60s, 120s, 180s, 240s, 300s, 360s, 400s, 460s, 520s, 600s, 1200s, 1800s, 2400s, 3600s, 6000s, 7200s, 10800s, 14400s, 18000s, 36000s, etc.

[0073] In some specific embodiments, the plasma discharge power source is provided via ICP, and the plasma discharge efficiency and the deposition rate of the hydrophilic film are further improved by applying a pulsed bias voltage to the support frame of the substrate. In some specific embodiments, the pulsed bias voltage is 100V to 1000V, specifically, for example, 100V, 200V, 300V, 400V, 500V, 600V, 700V, 800V, 900V, or 1000V, etc.; the pulse duty cycle is 5% to 80%, specifically... For example, it could be 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, or 80%, etc.; the pulse frequency is 10Hz to 300kHz, specifically for example: 10Hz, 60Hz, 100Hz, 200Hz, 250Hz, 300Hz, 500Hz, 1kHz, 2kHz, 3kHz, 4kHz, 5kHz, 10kHz, 20kHz, 50kHz, 100kHz, 200kHz, 300kHz, etc.

[0074] To better coordinate the ICP discharge with the pulse bias applied by the support frame, in some specific embodiments, pulse discharge is provided by ICP, while a pulse bias is applied to the support frame supporting the substrate. The pulse duty cycle and pulse frequency of the ICP pulse discharge are matched with the pulse duty cycle and pulse frequency of the pulse bias.

[0075] In some specific embodiments of the preparation method disclosed herein, the substrate is activated before introducing the vapor including organosilicon monomer into the reaction chamber. Specifically, this includes: providing the substrate and placing it in the reaction chamber, evacuating to a vacuum of 10-200 mTorr, introducing one or more of helium, argon, or oxygen, and activating plasma discharge to activate the substrate.

[0076] In some specific embodiments, when activating the substrate, the plasma discharge is a continuous discharge with a discharge power of 10–600 W, specifically, for example: 10 W, 50 W, 60 W, 100 W, 120 W, 200 W, 300 W, 400 W, 500 W, or 600 W, etc. The discharge time is 60–600 s, specifically, for example: 60 s, 120 s, 180 s, 240 s, 300 s, 360 s, 400 s, 460 s, 520 s, or 600 s, etc.

[0077] In some specific embodiments, when activating the substrate, the plasma discharge is a pulsed discharge with a discharge power of 10–600 W, specifically, for example: 10 W, 50 W, 100 W, 180 W, 200 W, 300 W, 400 W, 500 W, or 600 W, etc. The pulse duty cycle is 0.1%–70%, specifically, for example, 0.1%, 1%, 10%, 25%, 35%, 50%, 60%, 65%, or 70%, etc. The pulse frequency is 10 Hz–300 kHz, specifically, for example, 10 Hz, 100 Hz, 200 Hz, 250 Hz, 300 Hz, 500 Hz, 1 kHz, 2 kHz, 3 kHz, 4 kHz, 5 kHz, 10 kHz, 20 kHz, 50 kHz, 100 kHz, 200 kHz, 300 kHz, etc. The discharge time is 60 to 600 seconds, specifically for example: 60 seconds, 120 seconds, 180 seconds, 240 seconds, 300 seconds, 360 seconds, 400 seconds, 460 seconds, 520 seconds, or 600 seconds, etc.

[0078] In some specific embodiments of the preparation method disclosed herein, after the coating is completed on the surface of the substrate, clean compressed air or inert gas is introduced until the plasma reaction chamber returns to atmospheric pressure, the plasma reaction chamber is opened, and the substrate is removed. In some specific embodiments, an inert gas, namely helium or argon, is introduced, and the flow rate of the inert gas is 5–300 sccm.

[0079] In order to improve the hydrophilic durability of the hydrophilic membrane, the preparation method of the specific embodiments of this disclosure further includes, in some specific embodiments, forming a plasma polymer film on the substrate after plasma deposition, and hydrolyzing the plasma polymer film to form a plasma polymer hydrolyzed membrane.

[0080] In some specific embodiments, the hydrolysis temperature is room temperature; in some specific embodiments, to further improve the degree of hydrolysis reaction, the hydrolysis temperature is 40℃ to 100℃, specifically, for example, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃ or 100℃, etc.

[0081] In some specific implementations, the hydrolysis solution is a neutral or alkaline solution.

[0082] The preparation method of the specific embodiments disclosed herein is to fully hydrolyze the hydrolyzable groups in the polymer formed by organosilicon monomers to form hydrophilic groups such as hydroxyl groups, thereby improving the hydrophilic durability of the polymer film. Different hydrolysis conditions and hydrolysis reaction times are set according to different organosilicon monomers.

[0083] In some specific embodiments, the hydrolysis condition of the plasma polymer membrane is an alkaline solution with a pH of 8 to 14. In some specific embodiments, the plasma polymer membrane is immersed in an alkaline solution with a pH of 8 to 14 so that the hydrolyzable groups can fully contact the alkaline solution.

[0084] In some specific embodiments, hydrolysis specifically includes: contacting the plasma-polymerized film formed on the substrate with an alkaline solution with a pH of 9-12, and immersing it at a temperature of 40°C-100°C for more than 2 hours, thereby forming a plasma-polymerized hydrolyzed film on the substrate. The plasma-polymerized hydrolyzed film formed after the hydrolysis reaction has better hydrophilic durability than the unhydrolyzed plasma-polymerized film.

[0085] In some specific embodiments, the substrate is immersed in an alkaline solution at a temperature of 40°C to 100°C for 2 hours to 24 hours, specifically for 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 20 hours, 21 hours, 22 hours, 23 hours, or 24 hours, etc.

[0086] In some specific embodiments, the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution.

[0087] In some specific embodiments of the preparation method disclosed herein, the substrate is glass, and the hydrophilic film formed by the organosilicon monomer has a strong bonding force with the glass; in some specific embodiments, the substrate is transparent glass, and the hydrophilic film formed on the substrate has good light transmittance, and the transmittance of the glass with the hydrophilic film formed is above 96% according to the ultraviolet-visible spectrophotometer test.

[0088] In some embodiments, the hydrophilic film is formed on a portion of the surface of the substrate; in other embodiments, the hydrophilic film is formed on the entire surface of the substrate.

[0089] Specific embodiments of this disclosure also provide a product, wherein at least a portion of the surface of the product has any of the above-mentioned hydrophilic films, thereby the surface of the product having the hydrophilic film has good hydrophilic properties.

[0090] In some specific embodiments, the product is a transparent product. Due to the good light transmittance of the hydrophilic film, the transparent product as a whole has good light transmittance. According to the UV-Vis spectrophotometer test, the transmittance of the product is above 96%.

[0091] The present disclosure will be further illustrated by specific embodiments below.

[0092] Example

[0093] Test Method Description

[0094] Film thickness: measured using a Filmetrics F20-UV thin film thickness meter (USA);

[0095] Water contact angle: Tested according to GB / T 30447-2013 "Method for Measurement of Contact Angle of Nanofilms" standard;

[0096] Transmittance: Measured using a Perkin-Elmer-Lambda 950 UV-Vis spectrophotometer (USA).

[0097] Water immersion test: The substrate forming the hydrophilic film is immersed in a deionized water solution for a certain period of time, then taken out and dried, and the water contact angle and thickness of the hydrophilic film are tested.

[0098] Durability test: The substrate forming the hydrophilic film is placed in a room temperature environment, and the water contact angle of the hydrophilic film is tested for a period of time >10°.

[0099] Example 1

[0100] (1) Activation: After cleaning and drying the glass substrate, place it on the rotating rack in the chamber of the coating equipment, evacuate to 70 mTorr, introduce oxygen into the chamber at a flow rate of 100 sccm, turn on plasma discharge in the chamber, discharge power of 300 W, activation treatment time of 5 min, and activate the substrate.

[0101] (2) Coating: Vinyltriethoxysilane monomer is introduced at a flow rate of 120 μL / min and then introduced into the chamber after vaporization. Oxygen is introduced into the chamber at a flow rate of 100 sccm and argon is introduced into the chamber at a flow rate of 30 sccm. ICP plasma discharge is started with a discharge power of 300 W. At the same time, a pulse bias voltage of 600 V is applied to the rotating frame with a pulse duty cycle of 30%. The vacuum degree of the chamber is maintained at 70 mTorr during the coating process, and the coating time is 30 min to form a plasma polymer film on the substrate surface.

[0102] (3) Post-treatment: After the coating is completed, the substrate is taken out and immersed in a 0.01 mol / L sodium hydroxide solution. After maintaining the temperature at 80°C for 4 hours, the substrate is taken out, rinsed with deionized water, and dried to obtain a substrate with plasma polymerization hydrolysis film.

[0103] (4) Testing: The substrate with hydrophilic film is tested for film thickness, transmittance, water contact angle, immersion and durability. The test results are recorded in Table 1 below.

[0104] Example 2

[0105] Steps (1) and (3) are the same as in Example 1; in step (2), the ICP discharge power is 500W, the rotating frame is not loaded with pulse bias voltage, and the rest is the same as in Example 1.

[0106] Example 3

[0107] Steps (1) and (3) are the same as in Example 1; in step (2), the ICP discharge power is 500W, and the rest are the same as in Example 1.

[0108] Example 4

[0109] Steps (1) and (3) are the same as in Example 1; in step (2), the ICP discharge power is 800W, and the rest are the same as in Example 1.

[0110] Example 5

[0111] Steps (1) and (3) are the same as in Example 1; in step (2), the ICP discharge power is 800W, the coating time is 60min, and the rest are the same as in Example 1.

[0112] Example 6

[0113] Step (1) is the same as in Example 1; in step (2), the ICP discharge power is 800W, the coating time is 60min, and the rest is the same as in Example 1; in step (3), the immersion time is 12h, and the rest is the same as in Example 1.

[0114] Example 7

[0115] Step (1) is the same as in Example 1; in step (2), the ICP discharge power is 800W, the coating time is 60min, and the rest is the same as in Example 1; in step (3), the immersion time is 24h, and the rest is the same as in Example 1.

[0116] Example 8

[0117] Step (1) is the same as in Example 1; in step (2), the monomer is vinyltrimethoxysilane, the ICP discharge power is 800W, and the rest is the same as in Example 1; in step (3), the heating time is 12h, and the rest is the same as in Example 1.

[0118] Example 9

[0119] Step (1) is the same as in Example 1; in step (2), the monomer is a mixture of vinyltriethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1, the ICP discharge power is 800W, and the rest is the same as in Example 1; in step (3), the heating time is 12h, and the rest is the same as in Example 1.

[0120] Example 10

[0121] Step (1) is the same as in Example 1; in step (2), the monomer is 3-aminopropylmethyldimethoxysilane, the ICP discharge power is 800W, and the rest is the same as in Example 1; in step (3), the heating time is 12h, and the rest is the same as in Example 1.

[0122] Example 11

[0123] Step (1) is the same as in Example 1; in step (2), the monomer is dimethyldimethoxysilane, the ICP discharge power is 800W, and the rest is the same as in Example 1; in step (3), the heating time is 12h, and the rest is the same as in Example 1.

[0124] Example 12

[0125] Steps (1) and (2) are the same as in Example 3; in step (3), the coated substrate is immersed in deionized water, and the rest is the same as in Example 3.

[0126] Example 13

[0127] Steps (1) and (2) are the same as in Example 3; in step (3), the coated substrate is immersed at room temperature, and the rest is the same as in Example 3.

[0128] Example 14

[0129] Steps (1) and (2) are the same as in Example 3, except for step (3).

[0130] Comparative Example 1

[0131] A blank glass substrate was used as a comparison, without any coating or post-processing steps.

[0132] Comparative Example 2

[0133] (1) Activation: After cleaning and drying the glass substrate, place it on the rotating rack in the chamber of the coating equipment, evacuate to 70 mTorr, introduce oxygen into the chamber at a flow rate of 100 sccm, turn on plasma discharge in the chamber, ICP discharge power of 300 W, activation treatment time of 5 min, and activate the substrate.

[0134] (2) Coating: Acrylic monomer is introduced at a flow rate of 120 μL / min and then introduced into the chamber after vaporization. Oxygen is introduced into the chamber at a flow rate of 100 sccm and argon is introduced into the chamber at a flow rate of 40 sccm. ICP plasma discharge is turned on with an ICP discharge power of 100 W. No bias voltage is applied to the rotating frame. The vacuum degree of the chamber is maintained at 70 mTorr during the coating process. The coating time is 30 min, and a plasma polymer film is formed on the surface of the substrate.

[0135] Comparative Example 3

[0136] In step (1), oxygen is replaced with argon, and the gas flow rate remains unchanged; in step (2), oxygen is replaced with argon, and the gas flow rate remains unchanged, and the rest is the same as in Example 1; step (3) is the same as in Example 8.

[0137] Table 1. Test data on hydrophilic membrane performance

[0138]

[0139] As shown in Table 1, the hydrophilic films in Examples 1-14 all exhibit good hydrophilicity and transmittance, with water contact angles below 9°. In contrast, the film prepared in Comparative Example 3 in a non-oxidizing atmosphere lacks hydrophilicity and exhibits some hydrophobicity. Compared to the blank substrate in Comparative Example 1, Examples 1-14 demonstrate better hydrophilicity and similar transmittance, indicating that the hydrophilic films are transparent and have good transmittance, and their formation on the substrate does not affect the substrate's light transmittance.

[0140] Comparing the water immersion test results of Examples 1-14 and Comparative Example 2, after immersion in water for 2 hours, the film thickness on the substrate of Examples 1-14 remained unchanged, while the film in Comparative Example 2 had dissolved, indicating that the hydrophilic film prepared by the monomer in Comparative Example 2 was not resistant to water immersion.

[0141] Comparing the hydrophilic membranes prepared in Examples 1-11 with those prepared in Example 14, all exhibited good hydrophilicity. In Example 14, without a post-treatment hydrolysis step, the water contact angle of the hydrophilic membrane was greater than 10° after being placed in a room temperature environment for 8 hours. The time for the water contact angle to be greater than 10° in a room temperature environment was much shorter than that of the hydrophilic membranes in Examples 1-11. The water contact angle of the hydrophilic membrane in Example 14, measured after soaking in water for 10 minutes, was greater than that of the hydrophilic membranes in Examples 1-11, indicating that the hydrophilic membrane after hydrolysis had better hydrophilic durability.

[0142] Comparing Examples 1-11 with Examples 12 and 13, the pH or temperature of hydrolysis in Examples 12 and 13 differed from that in Examples 1-11. Based on the results of the 10-minute soaking test and the durability test at room temperature of the hydrophilic membrane after hydrolysis, the hydrophilic durability of the hydrophilic membranes in Examples 12 and 13 was not as good as that of the hydrophilic membranes in Examples 1-11. This indicates that hydrolysis in a suitable temperature and alkaline solution after post-treatment helps to improve the durability of the hydrophilic membrane.

[0143] Examples 1, 3, and 4 use different discharge powers. The thickness of the film layer is dependent on the power. Within a certain power range, the higher the power, the faster the coating speed and the thicker the film layer. Within a certain power range, the hydrophilic film prepared under higher power conditions has a smaller water contact angle after soaking in water for 10 minutes and a longer durability test time at room temperature.

[0144] In Examples 2 and 3, the rotating frame in Example 2 was not subjected to pulse bias voltage. Pulse bias voltage accelerates the film formation speed, resulting in a thicker hydrophilic film in Example 3. The pulse bias voltage has no significant effect on the durability of the hydrophilic film.

[0145] The coating process in Examples 5, 6 and 7 is the same. The difference in the post-treatment process is the different heating and alkali soaking time of the substrate. Within a certain range, extending the post-treatment time can provide durability of the hydrophilic film.

[0146] In Examples 8, 9, 10 and 11, different organosilicon monomers were used to form hydrophilic films through plasma polymerization. Compared with Examples 8, 9 and 11, the monomer in Example 10 has hydrophilic amino groups, and the hydrophilic film formed requires a longer time to maintain a water contact angle greater than 10° at room temperature, thus exhibiting better durability.

[0147] The above description is merely an exemplary embodiment used to illustrate the principles of this disclosure and is not intended to limit the scope of protection of this disclosure. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and substance of this disclosure, and these modifications and improvements are also within the scope of protection of this disclosure.

Claims

1. A hydrophilic membrane, characterized in that, The hydrophilic membrane is a plasma-polymerized hydrolyzed membrane formed by the hydrolysis of a plasma-polymerized membrane formed by depositing an organosilicon monomer and a gas including an oxidizing gas on at least a portion of the surface of a substrate under plasma excitation. The organosilicon monomer has the structure shown in formula (1) or formula (2). , （1） （2） In formula (1), R1, R2, and R3 are independently selected from: hydrogen atom, halogen atom, C1-C8 hydrocarbon group, C1-C8 hydroxyl group, C1-C8 hydrocarbon group with hydrophilic substituent, C1-C8 hydroxyl group with hydrophilic substituent, or C1-C containing at least one heteroatom in the chain. 20 The hydrocarbon group; R4 is selected from hydrogen atom, C1-C8 hydrocarbon group or C1-C8 hydrocarbon acyl group; n is an integer from 1 to 50; In formula (2), R5 is selected from: hydrogen atom, halogen atom, C1-C8 hydrocarbon group, C1-C8 hydroxyl group, C1-C8 hydrocarbon group with hydrophilic substituent, C1-C8 hydroxyl group with hydrophilic substituent, or C1-C containing at least one heteroatom in the chain. 20 The hydrocarbon group; R6 is selected from C1-C8 hydrocarbon oxy groups or C1-C8 hydrocarbon acyl oxy groups; m is an integer from 3 to 10.

2. The hydrophilic membrane according to claim 1, characterized in that, The hydrophilic substituents include one or more of the following: hydroxyl, amino, carboxyl, amine, ether, or sulfonic acid groups.

3. The hydrophilic membrane according to claim 1, characterized in that, The hydrophilic substituent has the structure shown in formula (3). ,（3） In formula (3), X is selected from hydrogen atom, hydroxyl, amino, carboxyl or sulfonic acid group; Y is selected from linkage, ether or amino group; Z is selected from linkage or C1-C8 alkylene group; wherein, when X is hydrogen atom, Y is not linkage. a is an integer from 1 to 4, and b is an integer from 1 to 4.

4. The hydrophilic membrane according to claim 1, characterized in that, The n is 1, R1 is a hydrogen atom, a C1-C4 hydrocarbon group, a C1-C4 hydrocarbon group with a hydrophilic substituent, or a C1-C4 hydroxyl group, R2 is a hydrogen atom, a C1-C4 hydrocarbon group, or a C1-C4 hydroxyl group, R3 is a C1-C4 hydroxyl group or a C1-C4 hydrocarbon group, and R4 is a C1-C4 hydrocarbon group.

5. The hydrophilic membrane according to claim 1, characterized in that, R5 is a hydrogen atom, a C1-C4 hydrocarbon group, a C1-C4 hydrocarbon group with a hydrophilic substituent, or a C1-C4 hydroxyl group, and R6 is a C1-C4 hydroxyl group.

6. The hydrophilic membrane according to claim 1, characterized in that, The organosilicon monomer is selected from one or more of the following: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutyl silicate, tetraisopropyl orthosilicate, tetra(isopropoxy)silane, methyltripropoxysilane, triethoxysilane, methyltriethoxysilane, dimethoxydimethylsilane, di-tert-butoxydimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, diethylenetriaminopropyltrimethoxysilane, and 3-aminopropylmethyldimethoxysilane.

7. The hydrophilic membrane according to claim 1, characterized in that, The oxidizing gases include one or more of the following: oxygen, nitrogen dioxide, ozone, hydrogen peroxide, and carbon dioxide.

8. The hydrophilic membrane according to any one of claims 1-7, characterized in that, The water contact angle of the hydrophilic membrane is no greater than 8°.

9. The hydrophilic membrane according to any one of claims 1-7, characterized in that, After the hydrophilic membrane is immersed in deionized water for 10 minutes, the water contact angle of the hydrophilic membrane is no greater than 30°.

10. The hydrophilic membrane according to any one of claims 1-7, characterized in that, The plasma-polymerized hydrolyzed membrane is placed in a room temperature environment, and the water contact angle of the plasma-polymerized hydrolyzed membrane is greater than 10° for more than 1 day.

11. A method for preparing a hydrophilic membrane, characterized in that, The method for preparing the hydrophilic membrane according to any one of claims 1-10 includes: The organosilicon monomer and a gas including an oxidizing gas are introduced into a cavity containing a substrate, and a plasma discharge is activated to perform plasma deposition on at least a portion of the surface of the substrate to form a plasma polymer film. The plasma polymerized membrane is hydrolyzed to form the plasma polymerized hydrolyzed membrane.

12. The preparation method according to claim 11, characterized in that, The hydrolysis includes contacting the plasma polymer membrane with an alkaline solution with a pH of 8-14 to perform hydrolysis.

13. The preparation method according to claim 12, characterized in that, The hydrolysis further includes: The plasma-polymerized membrane formed on the substrate is contacted with an alkaline solution with a pH of 9 to 12 and immersed at a temperature of 40°C to 100°C for more than 2 hours, thereby forming the plasma-polymerized hydrolyzed membrane on the substrate.

14. The preparation method according to claim 11, characterized in that, The plasma deposition includes: introducing vapor containing the organosilicon monomer into a reaction chamber, introducing oxygen, maintaining a vacuum of 10-200 mTorr in the reaction chamber, and activating plasma discharge to deposit a film on the substrate.

15. The preparation method according to claim 14, characterized in that, Before introducing the vapor containing the organosilicon monomer into the reaction chamber, the substrate is provided and placed in the reaction chamber, the vacuum is evacuated to 10-200 mTorr, one or more of helium, argon or oxygen are introduced, and plasma discharge is activated to activate the substrate.

16. The preparation method according to claim 14 or 15, characterized in that, The discharge power of the plasma discharge is 100W~1000W; During the coating process, a pulse bias voltage is applied to the support frame supporting the substrate. The pulse bias voltage is 100V~1000V, the pulse frequency is 10Hz~300kHz, the pulse duty cycle is 5%~80%, and the plasma discharge time is 100s~36000s.

17. The preparation method according to claim 16, characterized in that, The plasma discharge is performed via ICP discharge, and the ICP discharge power is 500W~1000W.

18. The preparation method according to any one of claims 11-15, characterized in that, The substrate is glass.

19. A product characterized in that, At least a portion of the surface of the product has a hydrophilic film as described in any one of claims 1-10.

20. The product according to claim 19, characterized in that, The product is transparent, and its transmittance, as measured by a UV-Vis spectrophotometer, is above 96%.

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