An antibacterial sealing element for an inner liner of a sterilization water path of a smart toilet and a preparation method thereof

Abstract

The application belongs to the technical field of sealing elements, and provides an inner lining antibacterial sealing element for a sterilization waterway of an intelligent toilet and a preparation method. The preparation method of the inner lining antibacterial sealing element comprises the following steps: S1. base pretreatment and plasma activation: after the vulcanized rubber base is ultrasonically cleaned and dried by isopropyl alcohol, the rubber base is placed in a reaction cavity of a low-pressure plasma treatment device; S2. in-situ graft polymerization: after the plasma treatment, a layer of antibacterial polymer brush coating is formed on the surface of the sealing element by using a gas phase deposition polymerization process or a liquid phase immersion-UV initiation polymerization process in an inert atmosphere without destroying the vacuum; S3. post-treatment: after the polymerization is completed, the sealing element is taken out, and deionized water at 60-70 DEG C is used for oscillation washing for 24-48 hours, so that the physical adsorption of the homopolymer and the unreacted monomer is completely removed, until the conductivity of the washing liquid is stable, and finally vacuum drying is performed until the weight is constant, and the preparation is completed.

Description

Technical Field

[0001] This invention belongs to the field of sealing technology, specifically relating to an antibacterial sealing component for the sterilization water circuit of a smart toilet and its preparation method. Background Technology

[0002] The warm air and warm water flushing functions of smart toilets rely on a complex internal water system. The rubber sealing rings, silicone pipes and other components in these water systems are in a humid and warm (25-40℃) environment for a long time, which makes them a breeding ground for microorganisms such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, forming a biofilm that is difficult to remove. There are three main types of existing solutions: (1) Adding antibacterial agents: Adding inorganic antibacterial agents (such as silver ions, nano zinc oxide) or organic antibacterial agents during rubber compounding. However, these additives have problems such as easy dissolution and failure, long-term decrease in antibacterial properties, possible changes in the physical properties of rubber or biosafety risks. (2) External sterilization module: such as ultraviolet (UV) lamps or electrolyzed water modules. These solutions are costly, energy-intensive, complex, and have blind spots or chemical residue risks. (3) Surface physical coating: Spraying or impregnating antibacterial coatings on the surface of the sealing components. The coating has weak adhesion to the substrate and is prone to wear and peeling under dynamic water flow and long-term deformation, resulting in a short antibacterial lifespan.

[0003] Therefore, there is an urgent need for a long-lasting antibacterial surface modification technology that can form a strong chemical bond with the matrix, prevent the migration of antibacterial components, and not affect the elasticity and durability of the seal body. Summary of the Invention

[0004] This invention aims to overcome the shortcomings of the prior art and provide an antibacterial sealing component for the sterilization water circuit of a smart toilet and its preparation method. The method uses gas phase plasma activated polymerization or liquid phase in-situ grafting polymerization to grow an antibacterial polymer brush coating layer firmly bonded by covalent bonds on the surface of a rubber matrix. This coating has excellent antibacterial properties, durability and biocompatibility.

[0005] The objective of this invention can be achieved through the following technical solutions: The first aspect of the present invention provides an antibacterial sealing element for the sterilization water circuit of a smart toilet, the antibacterial sealing element comprising a rubber matrix and an antibacterial polymer brush coating firmly bonded to the inner surface of the matrix by covalent bonds; the antibacterial polymer brush coating comprises a copolymer of polymerizable quaternary ammonium salt monomer and zwitterionic monomer.

[0006] Furthermore, the raw materials for the antibacterial polymer brush coating include the following components in parts by weight: 70-85 parts of polymerizable quaternary ammonium salt monomer, 15-30 parts of zwitterionic monomer, and 1-5 parts of crosslinking agent.

[0007] Furthermore, the raw materials for the antibacterial polymer brush coating include the following components in parts by weight: 70-85 parts of polymerizable quaternary ammonium salt monomer, 15-30 parts of zwitterionic monomer, 1-5 parts of crosslinking agent, and 0.5-2 parts of photoinitiator.

[0008] Furthermore, the polymerizable quaternary ammonium salt monomer is (meth)acryloyloxyethyltrimethylammonium chloride (DMC) or (meth)acryloyloxyethyldimethylbenzylammonium chloride (DBA). Its polymer backbone is covalently connected to the matrix, and the quaternary ammonium salt cationic end groups disrupt the bacterial cell membrane through electrostatic interaction, resulting in contact sterilization without releasing metal ions.

[0009] Furthermore, the zwitterionic comonomer is methacryloxyethyl phosphorylcholine (MPC) or sulfobetaine methacrylate (SBMA). The introduction of the zwitterionic comonomer forms a highly hydrophilic hydration layer, effectively resisting the adhesion of proteins and non-microbial dirt, preventing the formation of a protective dirt film that would affect antibacterial efficiency.

[0010] Furthermore, the crosslinking agent is polyethylene glycol diacrylate (PEGDA, Mn=400-700). The introduction of the crosslinking agent allows for the formation of a suitable crosslinked network between the polymer brushes, improving the wear resistance and stability of the coating and preventing excessive swelling or detachment of the polymer chains in the water flow.

[0011] Furthermore, the photoinitiator is photoinitiator 1173 (2-hydroxy-2-methyl-1-phenyl-1-propanone).

[0012] Furthermore, the rubber matrix is ​​addition-type liquid silicone rubber or peroxide-cured EPDM rubber.

[0013] A second aspect of the present invention provides a method for preparing an antibacterial sealing element for the sterilization water circuit of a smart toilet, comprising the following steps: S1. Matrix pretreatment and plasma activation After the vulcanized rubber matrix is ​​ultrasonically cleaned and dried with isopropanol, it is placed in the reaction chamber of a low-pressure plasma treatment device; the plasma bombardment generates a large number of free radicals and active groups (such as -OH, -COOH) on the rubber surface, forming highly reactive initiation sites; S2. In-situ grafting polymerization After plasma treatment, without breaking the vacuum or immediately in an inert atmosphere, an antibacterial polymer brush coating is formed on the surface of the seal using a vapor deposition polymerization process or a liquid phase impregnation-UV initiation polymerization process. S3. Post-processing After polymerization is complete, remove the sealed parts and wash them with deionized water at 60-70℃ for 24-48 hours to thoroughly remove physically adsorbed homopolymers and unreacted monomers until the conductivity of the washing solution stabilizes. Finally, vacuum dry them at 60℃ to constant weight to complete the process.

[0014] Furthermore, the activation gas used in the S1 reaction chamber is argon or a mixture of argon and oxygen in a volume ratio of 9:1.

[0015] Furthermore, the vacuum level of the S1 reaction chamber is 10-50 Pa, the radio frequency power is 100-300 W, and the processing time is 60-180 seconds.

[0016] Furthermore, the vapor deposition polymerization process in S2 includes the following steps: A mixed vapor consisting of polymerizable quaternary ammonium salt monomers, zwitterionic monomers, and crosslinking agents is introduced into the reaction chamber, and the pressure is controlled at 100-300 Pa for 30-60 minutes to complete the reaction. This technical solution utilizes residual free radicals on the surface to initiate a polymerization reaction of the monomers, resulting in a polymer brush coating with a long-lasting antibacterial effect on the surface of the sealing component.

[0017] Furthermore, the liquid-phase impregnation-UV-initiated polymerization process in S2 includes the following steps: The sealing component is rapidly immersed in an ethanol-water solution containing polymerizable quaternary ammonium salt monomers, zwitterionic monomers, crosslinking agents, and photoinitiators. After purging with nitrogen to remove oxygen, it is irradiated with ultraviolet light (wavelength 365nm) for 30-120 minutes to complete the process. This technical solution utilizes free radicals generated from surface free radicals or photoinitiator decomposition to initiate graft copolymerization of monomers in the solution onto the substrate surface, ultimately forming a polymer brush coating with a long-lasting antibacterial effect on the sealing component surface.

[0018] Furthermore, the total concentration of monomers in the ethanol-water solution of the liquid phase impregnation-UV initiated polymerization process is 5-15 wt%.

[0019] The beneficial effects of this invention are: 1. Long-lasting antibacterial mechanism: The polymer brush coating for contact sterilization is permanently connected to the rubber matrix through covalent bonds, with no leaching. The antibacterial lifespan is synchronized with the product lifespan, fundamentally solving the failure problem of traditional additive antibacterial agents.

[0020] 2. Superior overall hygiene performance: Quaternary ammonium salts provide highly effective sterilization, while zwitterionic polymers provide antifouling properties. The two work synergistically to keep the surface clean for a long time and prevent biofilm formation.

[0021] 3. High safety and compatibility: It does not introduce heavy metals and has no risk of releasing harmful substances; the ultra-thin coating does not affect the elasticity and sealing function of the seals and is fully compatible with existing smart toilet water systems.

[0022] 4. Strong process versatility: This method can be applied to various types of internal sealing components such as silicone tubes, rubber sealing rings, and silicone valve plates, and is easy to industrialize. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example Example 1 This embodiment provides an antibacterial sealing component for the sterilization water circuit of a smart toilet and its preparation method: A method for preparing an antibacterial sealing element for the sterilization water circuit of a smart toilet includes the following steps: S1. Matrix pretreatment and plasma activation After being ultrasonically cleaned and dried with isopropanol, the addition-cured liquid silicone rubber matrix after vulcanization was placed in the reaction chamber of a low-pressure plasma treatment device. Argon was used as the activation gas in the reaction chamber, with a vacuum of 20 Pa, a radio frequency power of 120 W, and a treatment time of 160 seconds. S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a vapor deposition polymerization process. The vapor deposition polymerization process includes the following steps: By weight, a mixed vapor consisting of 70 parts (meth)acryloyloxyethyltrimethylammonium chloride, 15 parts methacryloyloxyethylphosphorylcholine, and 1 part polyethylene glycol diacrylate is introduced into the reaction chamber, the pressure is controlled at 150 Pa, and it is maintained for 50 minutes to complete the process. S3. Post-processing After polymerization is complete, remove the sealed parts and wash them with deionized water at 60°C for 46 hours to thoroughly remove physically adsorbed homopolymers and unreacted monomers until the conductivity of the washing solution stabilizes. Finally, vacuum dry them at 60°C to constant weight to complete the process.

[0025] An antibacterial sealing liner for the sterilization water circuit of a smart toilet is prepared by the above steps.

[0026] Example 2 The only difference from Example 1 is that step S1 is different: S1. Matrix pretreatment and plasma activation After being ultrasonically cleaned and dried with isopropanol, the addition-cured liquid silicone rubber matrix after vulcanization is placed in the reaction chamber of a low-pressure plasma treatment device. The reaction chamber uses a mixture of argon and oxygen in a volume ratio of 9:1 as the activation gas, with a vacuum degree of 40 Pa, a radio frequency power of 250 W, and a treatment time of 120 seconds.

[0027] Example 3 The only difference from Example 1 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a vapor deposition polymerization process. The vapor deposition polymerization process includes the following steps: By weight, a mixed vapor consisting of 85 parts (meth)acryloyloxyethyl dimethyl benzyl ammonium chloride, 30 parts sulfonate betaine methacrylate, and 5 parts polyethylene glycol diacrylate is introduced into the reaction chamber, the pressure is controlled at 200 Pa, and it is maintained for 50 minutes to complete the process.

[0028] Example 4 The only difference from Example 1 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a liquid-phase impregnation-UV-initiated polymerization process. The liquid phase impregnation-UV initiated polymerization process includes the following steps: By weight, the sealing component is quickly immersed in an ethanol aqueous solution containing 70 parts (meth)acryloyloxyethyltrimethylammonium chloride, 15 parts sulfonate betaine methacrylate, 1 part polyethylene glycol diacrylate and 0.5 parts photoinitiator 1173 (total monomer concentration is 8 wt%). After purging with nitrogen to remove oxygen, it is irradiated with ultraviolet light (wavelength 365 nm) for 100 minutes to complete the process.

[0029] Example 5 The only difference from Example 1 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a liquid-phase impregnation-UV-initiated polymerization process. The liquid phase impregnation-UV initiated polymerization process includes the following steps: By weight, the sealing component is quickly immersed in an ethanol-water solution containing 85 parts (meth)acryloyloxyethyl dimethyl benzyl ammonium chloride, 30 parts methacryloyloxyethyl phosphorylcholine, 5 parts polyethylene glycol diacrylate, and 1.5 parts photoinitiator 1173 (total monomer concentration is 12 wt%). After purging with nitrogen to remove oxygen, it is irradiated with ultraviolet light (wavelength 365 nm) for 30-120 minutes to complete the process.

[0030] Example 6 The only difference from Example 1 is that step S3 is different: S3. Post-processing After polymerization is complete, remove the sealed parts and wash them with deionized water at 70°C for 24 hours to thoroughly remove physically adsorbed homopolymers and unreacted monomers until the conductivity of the washing solution stabilizes. Finally, vacuum dry them at 60°C to constant weight to complete the process.

[0031] Comparative Example Comparative Example 1 The only difference from Example 1 is that step S1 is different: S1. Matrix pretreatment and plasma activation After being ultrasonically cleaned and dried with isopropanol, the addition-cured liquid silicone rubber matrix after vulcanization is placed in the reaction chamber of a low-pressure plasma treatment device. The reaction chamber uses a mixture of argon and oxygen in a volume ratio of 9:3 as the activation gas, with a vacuum degree of 20 Pa, a radio frequency power of 120 W, and a treatment time of 160 seconds.

[0032] Comparative Example 2 The only difference from Example 1 is that step S1 is different: S1. Matrix pretreatment and plasma activation After being ultrasonically cleaned and dried with isopropanol, the addition-cured liquid silicone rubber matrix after vulcanization is placed in the reaction chamber of a low-pressure plasma treatment device. The reaction chamber uses argon as the activation gas, with a vacuum of 20 Pa, a radio frequency power of 80 W, and a treatment time of 40 seconds.

[0033] Comparative Example 3 The only difference from Example 1 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a vapor deposition polymerization process. The vapor deposition polymerization process includes the following steps: By weight, a mixed vapor consisting of 70 parts (meth)acryloyloxyethyltrimethylammonium chloride and 1 part polyethylene glycol diacrylate is introduced into the reaction chamber, the pressure is controlled at 150 Pa, and it is maintained for 50 minutes to complete the process.

[0034] Comparative Example 4 The only difference from Example 1 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a vapor deposition polymerization process. The vapor deposition polymerization process includes the following steps: By weight, a mixed vapor consisting of 15 parts of methacryloyloxyethyl phosphorylcholine and 1 part of polyethylene glycol diacrylate is introduced into the reaction chamber, the pressure is controlled at 150 Pa, and it is maintained for 50 minutes to complete the process.

[0035] Comparative Example 5 The only difference from Example 1 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a vapor deposition polymerization process. The vapor deposition polymerization process includes the following steps: By weight, a mixed vapor consisting of 50 parts (meth)acryloyloxyethyltrimethylammonium chloride, 47 parts methacryloyloxyethylphosphorylcholine, and 1 part polyethylene glycol diacrylate is introduced into the reaction chamber, the pressure is controlled at 150 Pa, and it is maintained for 50 minutes to complete the process.

[0036] Comparative Example 6 The only difference from Example 4 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a liquid-phase impregnation-UV-initiated polymerization process. The liquid phase impregnation-UV initiated polymerization process includes the following steps: By weight, the seal is quickly immersed in an ethanol aqueous solution containing 70 parts (meth)acryloyloxyethyltrimethylammonium chloride, 1 part polyethylene glycol diacrylate and 0.5 parts photoinitiator 1173 (total monomer concentration is 8 wt%). After purging with nitrogen to remove oxygen, it is irradiated with ultraviolet light (wavelength 365 nm) for 100 minutes to complete the process.

[0037] Comparative Example 7 The only difference from Example 4 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a liquid-phase impregnation-UV-initiated polymerization process. The liquid phase impregnation-UV initiated polymerization process includes the following steps: By weight, the sealing component is rapidly immersed in an ethanol-water solution containing 15 parts of sulfonate betaine methacrylate, 1 part of polyethylene glycol diacrylate, and 0.5 parts of photoinitiator 1173 (total monomer concentration 8 wt%). After purging with nitrogen to remove oxygen, it is irradiated with ultraviolet light (wavelength 365 nm) for 100 minutes to complete the process. Comparative Example 8 The only difference from Example 4 is that step S2 is different: S2. In-situ grafting polymerization After plasma treatment, without disrupting the vacuum or immediately under an inert atmosphere, an antibacterial polymer coating is formed on the surface of the seal using a liquid-phase impregnation-UV-initiated polymerization process. The liquid phase impregnation-UV initiated polymerization process includes the following steps: By weight, the sealing component is quickly immersed in an ethanol aqueous solution containing 95 parts (meth)acryloyloxyethyltrimethylammonium chloride, 8 parts sulfonate betaine methacrylate, 1 part polyethylene glycol diacrylate and 0.5 parts photoinitiator 1173 (total monomer concentration is 8 wt%). After purging with nitrogen to remove oxygen, it is irradiated with ultraviolet light (wavelength 365 nm) for 100 minutes to complete the process.

[0038] Comparative Example 9 The only difference from Example 1 is that step S3 is different: S3. Post-processing After polymerization is complete, remove the sealed parts and wash them with deionized water at 40°C for 46 hours to thoroughly remove physically adsorbed homopolymers and unreacted monomers until the conductivity of the washing solution stabilizes. Finally, vacuum dry them at 60°C to constant weight to complete the process.

[0039] Performance testing The seals prepared in Examples 1-6 and Comparative Examples 1-9 were subjected to the following performance tests: (1) Verification of chemical bonding The seals prepared in Examples 1-6 were analyzed using FT-IR and XPS. The presence of C=O and quaternary ammonium salt N on the surface of the silicone rubber of the seals was detected. + Characteristic absorption peaks of (CH3)3 and phosphate ester / sulfonic acid groups. After vigorous ultrasonic washing of the seal, the characteristic peak intensity remained unchanged upon re-examination, indicating that the antibacterial polymer brush coating is chemically bonded to the rubber matrix, rather than physically adsorbed.

[0040] (2) Security testing Metal ion leaching: The seals prepared in Examples 1-6 were immersed in deionized water at 40°C for 30 days. The immersion solution was analyzed by inductively coupled plasma mass spectrometry (ICP-MS), and no dissolved silver, zinc, or other metal ions were detected. The seals prepared by this invention do not release heavy metals during use. They employ a contact quaternary ammonium salt sterilization mechanism, fundamentally eliminating the risk of heavy metal leaching and avoiding the bioaccumulation and ecological risks that may be caused by traditional silver / zinc antibacterial agents.

[0041] Organic leaching: The seals from Examples 1-6 were immersed in deionized water at 40°C for 30 days. The immersion solution was analyzed by liquid chromatography-mass spectrometry (LC-MS), and no trace amounts of organic monomers were detected. This indicates that the seals prepared by this invention possess excellent chemical stability. Through covalent bonding treatment, zero organic residue is achieved, ensuring hygienic safety upon contact with water.

[0042] (3) Antibacterial performance test The antibacterial properties of the seals prepared in Examples 1-6 and Comparative Examples 1-9 were tested according to JIS Z 2801 / ISO 22196 standards. *Escherichia coli* and *Staphylococcus aureus* were used as test bacteria. After the seals were in contact with the bacterial solution for 24 hours, the antibacterial properties were tested. After accelerated aging in 85°C hot water for 1000 hours, the antibacterial rate was measured. The test results are shown in Table 1. Table 1

[0043] As shown in Table 1, the seals prepared in Examples 1-6 all achieved antibacterial rates >99.99% against Escherichia coli and Staphylococcus aureus. This indicates that the polymer brush coatings formed by plasma-activated graft polymerization or liquid-phase impregnation-UV-initiated graft polymerization can fully utilize the contact bactericidal effect of quaternary ammonium salt monomers to achieve highly efficient sterilization. Furthermore, after 1000 hours of accelerated aging in 85°C hot water, the antibacterial rate remained stably above 99.9%. This demonstrates that the coating is not simply a physical adhesion, but rather firmly bonded to the rubber matrix surface through covalent bonds, exhibiting extremely strong resistance to heat aging and hydrolysis, and a long antibacterial lifespan.

[0044] As can be seen from Comparative Examples 1-2 and Example 1, when the plasma process activation conditions are not right, it will lead to insufficient or excessive plasma activation, resulting in insufficient surface active sites, low grafting rate, poor antibacterial performance and insufficient durability of the seal.

[0045] As can be seen from the comparison of Comparative Examples 3 and 6 with Example 1, Comparative Examples 3 and 6 lack zwitterionic monomers. Although they contain quaternary ammonium salts for sterilization, their antifouling performance is poor. Therefore, after long-term use, proteins are easily adsorbed to form biofilms, resulting in a significant decrease in antibacterial rate after aging.

[0046] As can be seen from the comparison of Comparative Examples 4 and 7 with Example 1, Comparative Examples 4 and 7 lack quaternary ammonium salt monomers and only contain zwitterionic polymers, which have antifouling properties but poor bactericidal function, resulting in poor antibacterial performance and insufficient durability of the seals.

[0047] As can be seen from the comparison of Comparative Examples 5 and 8 with Example 1, different proportions of each component can affect the synergistic effect, resulting in poor antibacterial properties, insufficient antifouling properties, poor coating stability, and a significant decrease in antibacterial performance after aging.

[0048] As can be seen from the comparison of Comparative Example 9 and Example 1, when the washing temperature is insufficient, there are certain residues of unreacted monomers and homopolymers, which affect the purity and stability of the coating, resulting in antibacterial performance that is slightly lower than that of Example 1.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. It should be understood that, in the various embodiments of this application, the sequence number of each process does not imply a sequential order of execution; some or all steps may be performed in parallel or sequentially; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0050] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application are available on the market or can be prepared by existing methods.

[0051] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and all technical features and optional technical features of this application can be combined to form new technical solutions.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An antibacterial sealing element for the sterilization water circuit of a smart toilet, characterized in that, The antimicrobial lining seal includes a rubber matrix and an antimicrobial polymer brush coating that is covalently bonded to the inner surface of the matrix; the antimicrobial polymer brush coating comprises a copolymer of polymerizable quaternary ammonium salt monomers and zwitterionic monomers.

2. The antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 1, characterized in that, The raw materials for the antibacterial polymer brush coating include the following components in parts by weight: 70-85 parts of polymerizable quaternary ammonium salt monomer, 15-30 parts of zwitterionic monomer, and 1-5 parts of crosslinking agent.

3. The antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 1, characterized in that, The raw materials for the antibacterial polymer brush coating include the following components in parts by weight: 70-85 parts of polymerizable quaternary ammonium salt monomer, 15-30 parts of zwitterionic monomer, 1-5 parts of crosslinking agent, and 0.5-2 parts of photoinitiator.

4. The antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 2, characterized in that, The polymerizable quaternary ammonium salt monomer is (meth)acryloyloxyethyltrimethylammonium chloride or (meth)acryloyloxyethyldimethylbenzylammonium chloride.

5. The antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 2, characterized in that, The zwitterionic comonomer is methacryloyloxyethyl phosphorylcholine or sulfonate betaine methacrylate; the crosslinking agent is polyethylene glycol diacrylate.

6. The antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 3, characterized in that, The photoinitiator is photoinitiator 1173.

7. The method for preparing an antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 1, characterized in that, Includes the following steps: S1. Matrix pretreatment and plasma activation After the vulcanized rubber matrix is ​​ultrasonically cleaned and dried with isopropanol, it is placed in the reaction chamber of a low-pressure plasma treatment device. S2. In-situ grafting polymerization After plasma treatment, without breaking the vacuum or immediately in an inert atmosphere, an antibacterial polymer brush coating is formed on the surface of the seal using a vapor deposition polymerization process or a liquid phase impregnation-UV initiation polymerization process. S3. Post-processing After polymerization is complete, remove the sealed parts and wash them with deionized water at 60-70℃ for 24-48 hours to thoroughly remove physically adsorbed homopolymers and unreacted monomers until the conductivity of the washing solution stabilizes. Finally, vacuum dry them at 60℃ to constant weight to complete the process.

8. A method for preparing an antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 7, characterized in that, The S1 reaction chamber uses argon or a mixture of argon and oxygen in a volume ratio of 9:1 as the activation gas; the vacuum degree of the S1 reaction chamber is 10-50 Pa, the radio frequency power is 100-300 W, and the processing time is 60-180 seconds.

9. A method for preparing an antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 7, characterized in that, The vapor deposition polymerization process in S2 includes the following steps: A mixture of polymerizable quaternary ammonium salt monomers, zwitterionic monomers, and crosslinking agents is introduced into the reaction chamber. The pressure is controlled at 100-300 Pa and maintained for 30-60 minutes to complete the reaction.

10. A method for preparing an antibacterial sealing element for the sterilization water circuit of a smart toilet according to claim 7, characterized in that, The liquid phase impregnation-UV-initiated polymerization process in S2 includes the following steps: The sealing element is quickly immersed in an ethanol-water solution containing polymerizable quaternary ammonium salt monomers, zwitterionic monomers, crosslinking agents, and photoinitiators, wherein the total concentration of monomers in the ethanol-water solution is 5-15 wt%. After purging with nitrogen to remove oxygen, it is irradiated with ultraviolet light for 30-120 minutes to complete the process.

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