Ceramic material with self-cleaning and antibacterial functions, and preparation method and application thereof

Abstract

The application provides a kind of ceramic material with self-cleaning and antibacterial function and its preparation method and application, which comprises the following components by mass percentage: 4.0-4.5% of rutile titanium dioxide, 3.0-4.0% of diiron trioxide, 2.5-3.0% of copper oxide, 1.0-2.0% of zinc oxide, 5.0-6.0% of aluminum trioxide, 40-50% of silicon dioxide, 30-35% of kaolin, 2.0-2.5% of magnesium oxide and 3.0-3.5% of calcium oxide. The material is prepared by the steps of batching and mixing, spray drying, shaping and sintering. The material is used for preparing building ceramic tiles, daily tableware or medical device parts. The application directly introduces specific proportion of rutile titanium dioxide, diiron trioxide and copper oxide functional components into ceramic matrix, builds multiple heterojunction and non-light-driven catalytic cycle system in the ceramic material, realizes efficient self-cleaning and antibacterial function of the ceramic material itself under lightless condition, introduces specific proportion of aluminum trioxide and silicon dioxide to significantly improve the mechanical properties of the ceramic material, and the integrated preparation process simplifies the production process.

Description

Technical Field

[0001] This invention belongs to the field of ceramic materials technology, specifically relating to a ceramic material with self-cleaning and antibacterial functions, its preparation method, and its application. Background Technology

[0002] Ceramic materials are widely used in construction, sanitary ware, home decoration, medical and public facilities due to their excellent mechanical strength, chemical stability, weather resistance and aesthetics. However, traditional ceramic materials are prone to stains, bacteria and microorganisms, especially in humid, frequently touched or poorly lit environments. This not only affects aesthetics and hygiene but may also become a medium for disease transmission. Therefore, developing ceramic materials with both long-lasting self-cleaning and antibacterial functions has become an important direction for industrial upgrading and meeting the demands of the high-end market.

[0003] For example, Chinese patent CN102898875A discloses a nano-self-cleaning antibacterial coating liquid and its application. This coating liquid is an ethanol solution containing TiO2 particles with a particle size of less than 50nm, as well as new elements such as V and Cr. It can convert visible light and infrared light into excitation light of TiO2, achieving the purpose of the nano-antibacterial film working in the absence of light. However, this patent uses an ethanol solution-type coating liquid, which needs to be coated on the surface of existing substrates such as ceramics and glass and cured at 500℃ to form a film. It cannot be directly used as a ceramic raw material for molding. At the same time, the coating relies on adhesion to the substrate for bonding, and long-term use is prone to wear, peeling, aging and other problems, resulting in the failure of the coating function.

[0004] Although existing technologies have attempted to prepare self-cleaning and antibacterial coatings for use in dark or low-light environments, the core mechanism of these coatings is the conversion of visible / infrared light into TiO2 excitation light, which essentially still relies on light and does not deviate from the core logic of photocatalysis. Furthermore, surface coating modifications easily lead to weak adhesion between the coating and the substrate, poor durability, and problems such as wear and peeling after long-term use. Therefore, how to achieve efficient self-cleaning and efficient antibacterial properties of ceramic materials in dark environments by integrating component and structure design, starting from the essence of the material, remains a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the above problems, the present invention provides a ceramic material with self-cleaning and antibacterial functions, its preparation method and application, which can prepare a ceramic material with efficient self-cleaning and antibacterial functions under no-light conditions, so as to overcome the dependence of traditional self-cleaning or antibacterial ceramic materials on light conditions, and avoid the problems of coating peeling and wear that may occur when coating is applied to the ceramic surface.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] The first aspect of the present invention provides a ceramic material with self-cleaning and antibacterial functions, comprising the following components in weight percentage: 4.0-4.5% rutile titanium dioxide, 3.0-4.0% ferric oxide, 2.5-3.0% copper oxide, 1.0-2.0% zinc oxide, 5.0-6.0% aluminum oxide, 40-50% silicon dioxide, 30-35% kaolin, 2.0-2.5% magnesium oxide, and 3.0-3.5% calcium oxide.

[0008] This invention provides a multiphase composite functional ceramic material that maintains highly efficient self-cleaning and antibacterial activity even in the absence of light, through specific component composition and microstructure design. Rutile titanium dioxide (TiO2), as one of the core functional components, participates in the construction of a multi-element heterojunction structure, promotes the separation and migration of photogenerated carriers, and introduces a non-photo-driven catalytic mechanism. Its definition does not involve concepts such as the number of carbon atoms or heteroatoms; its crystal structure is rutile, and this specific crystal structure is crucial for achieving the material's self-cleaning function in the absence of light. Its mass percentage content ranges from 4.0% to 4.5%, within which the ceramic material can effectively balance self-cleaning performance with other properties. Ferric oxide (Fe2O3) provides Fe... 3+ Participating in the valence change of metal ions (Fe 3+ / Fe 2+ The non-photocatalytic mechanism of copper oxide (CuO) is defined without involving the number of carbon atoms or heteroatoms. Its mass percentage is 3.0–4.0%, at which point it can effectively synergize with other components to achieve photofree self-cleaning and antibacterial functions. CuO provides Cu... 2+It possesses a dual antibacterial mechanism of contact killing (destroying cell membranes) and ion slow release (inactivating intracellular enzymes); its mass percentage is 2.5~3.0%, at which ratio it can effectively synergize with other components to achieve light-free self-cleaning and antibacterial functions. Zinc oxide (ZnO) has a mass percentage of 1.0~2.0%, and works synergistically with other metal oxides to jointly affect the self-cleaning and antibacterial properties of the material. Although it does not have the complex definition parameters of traditional substituents, a specific proportion range has a positive impact on the overall performance. Aluminum oxide (Al2O3) has a mass percentage of 5.0~6.0%, which significantly improves the mechanical strength and toughness of ceramic materials through a "pinning and toughening" effect; its definition is mainly based on its chemical composition, and it plays a key role in improving the mechanical properties of the material by interacting with other components. Silica (SiO2), as a matrix material, promotes sintering densification and synergistically improves the strength and maximum firing temperature of ceramics with other components. Kaolin, as a common raw material for ceramic preparation, provides the basic ceramic skeleton structure for the material, providing good plasticity and sintering performance. Magnesium oxide (MgO) participates in the formation of a stable crystal structure in the material, and together with other oxides, it influences the sintering process and final properties. Calcium oxide (CaO) plays a role in regulating the sintering temperature and improving the microstructure of the material, synergistically enhancing the overall performance of the material with other components, and improving its sintering characteristics and mechanical properties. Furthermore, the various components are interconnected through chemical bonds and physical interactions. It should be noted that this invention selects rutile titanium dioxide because its specific crystal structure plays a crucial role in achieving the material's properties; other metal oxides also participate in the material composition with their stable crystal structures, and the combination and interaction between different crystal structures jointly determine the material's properties.

[0009] Furthermore, the mass ratio of rutile titanium dioxide, ferric oxide and copper oxide is (4.0~4.5):(3.0~4.0):(2.5~3.0).

[0010] Among them, rutile titanium dioxide (TiO2), ferric oxide (Fe2O3) and copper oxide (CuO) in a specific ratio form a multi-element heterojunction structure. Through the interaction between atoms, a specific connection mode is formed inside the material, which promotes the separation and migration of photogenerated charge carriers.

[0011] Furthermore, the mass ratio of aluminum oxide to silicon dioxide is 1:(7.5~10.0).

[0012] In particular, aluminum oxide (Al2O3) and silicon dioxide (SiO2) in a specific ratio achieve a tight bond through the synergistic effect of "pinning toughening" and "promoting sintering densification", thereby improving the mechanical properties of the material.

[0013] Preferably, the composition comprises the following components in weight percentage: 4.2% rutile titanium dioxide, 3.5% ferric oxide, 2.8% copper oxide, 1.5% zinc oxide, 5.5% aluminum oxide, 45% silicon dioxide, 32% kaolin, 2.4% magnesium oxide, and 3.1% calcium oxide.

[0014] A second aspect of the present invention provides a method for preparing a ceramic material with self-cleaning and antibacterial functions, comprising the following steps:

[0015] S1. Ingredients and mixing: Weigh each raw material according to the ratio, and ball mill and mix them with deionized water as the medium for 3~5 hours to obtain a uniform slurry with a particle size D50≤2μm;

[0016] S2. Spray drying: The uniform slurry is spray dried to obtain a composite powder;

[0017] S3. Molding: The composite powder is dry-pressed to obtain a blank with dimensions of 100mm×100mm×100mm;

[0018] S4. Sintering: Sinter the green body for 1~3 hours to obtain the ceramic material.

[0019] Furthermore, the spray drying in step S2 is carried out under the conditions of an inlet air temperature of 160~200℃ and an outlet air temperature of 80~100℃.

[0020] Furthermore, the pressure for dry pressing in step S3 is 25~35MPa.

[0021] Furthermore, the heating rate of sintering in step S4 is 0.5~5℃ / min, and the sintering temperature is 1250~1350℃.

[0022] In step S1 of this invention, deionized water is used as the medium to mix and refine the raw materials using a ball mill, ensuring thorough and uniform mixing. In step S2, the uniform slurry is processed into granular powder using a spray drying device. In step S3, the composite powder is pressed into a blank of the desired shape using a dry pressing machine. In step S4, the blank is sintered at a high temperature of 1250~1350℃ in a high-temperature kiln; the specific sintering temperature is adjusted according to the specific product requirements, such as 1250℃ for self-cleaning antibacterial ceramic tiles and 1350℃ for high-toughness ceramic tableware.

[0023] A third aspect of the present invention provides an application of a ceramic material with self-cleaning and antibacterial functions for the manufacture of building ceramic tiles, tableware, or medical device components.

[0024] The ceramic materials with self-cleaning and antibacterial functions provided in this application can be widely used in various fields such as building decoration, daily necessities, and medical devices. Specific products include, but are not limited to, self-cleaning and antibacterial ceramic tiles, high-toughness ceramic tableware, and antibacterial medical device components.

[0025] Compared with the prior art, the technical solution of this application has at least the following beneficial effects:

[0026] This invention directly introduces functional components of rutile titanium dioxide, ferric oxide, and copper oxide in a specific ratio into a ceramic matrix. By constructing a multi-element heterostructure and a non-photo-driven catalytic cycle system within the ceramic material, it achieves highly efficient self-cleaning and antibacterial functions of the ceramic material itself under light-free conditions, fundamentally avoiding the problem of functional failure caused by easy wear and peeling of ceramic surface coatings. Specifically, the ceramic material of this invention achieves a 24-hour degradation rate of over 52% for methylene blue and over 85% for olive oil in a completely dark environment, and exhibits an antibacterial rate of over 99.9% against Escherichia coli and Staphylococcus aureus. Simultaneously, by introducing a specific ratio of aluminum oxide and silicon dioxide, this invention significantly improves the mechanical properties of the ceramic material, achieving a fracture toughness of 4.3 ± 0.4 MPa·m. 1 / 2 It boasts a flexural strength of 82±7MPa and a maximum applicable firing temperature of 1400℃. Furthermore, the ceramic material's long-lasting self-cleaning and antibacterial properties significantly reduce the use of cleaning and disinfectant agents, offering environmental advantages. Its integrated manufacturing process simplifies production and expands its application prospects in building tiles, tableware, and medical devices. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0028] The term "comprising" as used in this application is an open-ended inclusion, meaning "including but not limited to". The term "according to" means "at least in part according to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Definitions of other terms will be given in the description below.

[0029] Example 1

[0030] The first aspect of the present invention provides a ceramic material with self-cleaning and antibacterial functions, comprising the following components by mass percentage: 4.0% rutile titanium dioxide, 3.2% ferric oxide, 2.7% copper oxide, 1.6% zinc oxide, 5.8% aluminum oxide, 45% silicon dioxide, 32% kaolin, 2.5% magnesium oxide, and 3.2% calcium oxide.

[0031] The mass ratio of rutile titanium dioxide, ferric oxide and copper oxide is 4.0 : 3.2 : 2.7.

[0032] The mass ratio of aluminum oxide to silicon dioxide is 1:7.76.

[0033] A second aspect of this invention provides a method for preparing a ceramic material with self-cleaning and antibacterial functions, comprising the following steps:

[0034] S1. Ingredients and mixing: Weigh each raw material according to the ratio, and ball mill and mix them with deionized water as the medium for 3 hours to obtain a uniform slurry with a particle size D50≤2μm;

[0035] S2. Spray drying: The uniform slurry obtained in step S1 is spray dried at an inlet air temperature of 160°C and an outlet air temperature of 80°C to obtain a composite powder.

[0036] S3. Molding: The composite powder obtained in step S2 is dry-pressed under a pressure of 25MPa to obtain a blank with a size of 100mm×100mm×100mm;

[0037] S4. Sintering: The green body obtained in step S3 is heated to 1250℃ at a heating rate of 5℃ / min and sintered for 1 hour. After cooling, a dense ceramic plate is obtained.

[0038] A third aspect of the present invention provides an application of a ceramic material with self-cleaning and antibacterial functions. This ceramic slab can be used to prepare building ceramic tiles and is suitable for building decoration fields such as walls and countertops.

[0039] Example 2

[0040] The first aspect of the present invention provides a ceramic material with self-cleaning and antibacterial functions, comprising the following components by mass percentage: 4.1% rutile titanium dioxide, 3.7% ferric oxide, 2.9% copper oxide, 1.7% zinc oxide, 5.1% aluminum oxide, 45% silicon dioxide, 32% kaolin, 2.3% magnesium oxide, and 3.2% calcium oxide.

[0041] The mass ratio of rutile titanium dioxide, ferric oxide and copper oxide is 4.1:3.7:2.9.

[0042] The mass ratio of aluminum oxide to silicon dioxide is 1:8.82.

[0043] A second aspect of this invention provides a method for preparing a ceramic material with self-cleaning and antibacterial functions, comprising the following steps:

[0044] S1. Ingredients and mixing: Weigh each raw material according to the ratio, and ball mill and mix them with deionized water as the medium for 4 hours to obtain a uniform slurry with a particle size D50≤2μm;

[0045] S2. Spray drying: The uniform slurry obtained in step S1 is spray dried at an inlet air temperature of 180°C and an outlet air temperature of 90°C to obtain a composite powder.

[0046] S3. Molding: The composite powder obtained in step S2 is dry-pressed under a pressure of 30MPa to obtain a blank with dimensions of 100mm×100mm×100mm;

[0047] S4. Sintering: The green body obtained in step S3 is heated to 1300℃ at a heating rate of 2℃ / min and sintered for 2 hours. After cooling, a ceramic cup or bowl with a smooth surface is obtained.

[0048] A third aspect of the present invention provides an application of a ceramic material with self-cleaning and antibacterial functions for the preparation of everyday tableware.

[0049] Example 3

[0050] The first aspect of the present invention provides a ceramic material with self-cleaning and antibacterial functions, comprising the following components by mass percentage: 4.0% rutile titanium dioxide, 3.2% ferric oxide, 2.7% copper oxide, 1.8% zinc oxide, 6.0% aluminum oxide, 45% silicon dioxide, 32% kaolin, 2.2% magnesium oxide, and 3.1% calcium oxide.

[0051] The mass ratio of rutile titanium dioxide, ferric oxide and copper oxide is 4.0 : 3.2 : 2.7.

[0052] The mass ratio of aluminum oxide to silicon dioxide is 1:7.5.

[0053] A second aspect of this invention provides a method for preparing a ceramic material with self-cleaning and antibacterial functions, comprising the following steps:

[0054] S1. Ingredients and mixing: Weigh each raw material according to the ratio, and ball mill and mix them with deionized water as the medium for 5 hours to obtain a uniform slurry with a particle size D50≤2μm;

[0055] S2. Spray drying: The uniform slurry obtained in step S1 is spray dried at an inlet air temperature of 200℃ and an outlet air temperature of 100℃ to obtain a composite powder;

[0056] S3. Molding: The composite powder obtained in step S2 is dry-pressed under a pressure of 35MPa to obtain a blank with dimensions of 100mm×100mm×100mm;

[0057] S4. Sintering: The green body obtained in step S3 is heated to 1320℃ at a heating rate of 0.5℃ / min and sintered for 3 hours. After cooling, a high-density, net-size medical ceramic structural part is obtained.

[0058] A third aspect of the present invention provides an application of a ceramic material with self-cleaning and antibacterial functions for the manufacture of medical device components.

[0059] Comparative Example 1

[0060] Anatase titanium dioxide was used instead of rutile titanium dioxide as the raw material, and the remaining components and proportions were exactly the same as in Example 1 (70% kaolin, 5% anatase titanium dioxide TiO2, 2% iron oxide (Fe2O3), 2% copper oxide (CuO), 2% zinc oxide (ZnO), 10% aluminum oxide (Al2O3), and 9% silicon dioxide (SiO2). The preparation process was the same as in Example 1, and the sintering temperature was 1350℃.

[0061] Objective: To compare the effects of rutile and anatase TiO2 on the self-cleaning and antibacterial properties of matte-finish TiO2. Comparative Example 2

[0062] No copper oxide (CuO) and ferric oxide (Fe2O3) were added. The remaining components and proportions were exactly the same as in Example 1 (70% kaolin, 5% rutile TiO2, 2% zinc oxide (ZnO), 10% aluminum oxide (Al2O3), and 9% silicon dioxide (SiO2). The preparation process was the same as in Example 1, and the sintering temperature was 1350℃.

[0063] Objective: To verify the key synergistic effect of CuO and Fe2O3 in constructing multi-component heterojunctions, achieving photocatalysis-free and highly efficient antibacterial properties.

[0064] Comparative Example 3

[0065] Without the addition of aluminum oxide (Al2O3) and silicon dioxide (SiO2), the remaining components and proportions were exactly the same as in Example 2 (60% feldspar, 3% rutile TiO2, 1% Fe2O3, 1% CuO, and 1% ZnO). The preparation process was the same as in Example 2, but the sintering temperature was adjusted to 1180℃ (due to the lack of Al2O3 / SiO2, the maximum applicable sintering temperature of the material was reduced).

[0066] Objective: To verify the enhancing effects of Al2O3 and SiO2 on the mechanical properties (flexural strength, fracture toughness) and sintering temperature of ceramics.

[0067] Performance testing methods:

[0068] 1. Self-cleaning performance test: (1) According to the ISO 10678:2010 standard, in a completely dark and sealed environment, the ceramic samples prepared in Examples 1-3 and Comparative Examples 1-2 were immersed in a methylene blue solution with a concentration of 10 mg / L and the degradation rate was tested for 24 h; (2) Under light-free conditions, the surface of the ceramic samples prepared in Examples 1-3 and Comparative Examples 1-2 was uniformly coated with 0.1 ml of olive oil and placed in an environment of 25°C and 60% relative humidity for 24 h, and the oil degradation rate of the ceramic samples was measured.

[0069] 2. Antibacterial performance test: According to GB / T 21866-2008 "Test method for antibacterial performance of antibacterial ceramic products", Escherichia coli and Staphylococcus aureus were used as test bacteria. They were inoculated on the surface of ceramic samples of Examples 1-3 and Comparative Examples 1-2 and the inhibition rate was calculated after 24 hours of incubation.

[0070] 3. Mechanical property testing: According to GB / T 6569-2006, the three-point bending method (span 20mm, loading speed 0.5mm / min) was used to test the flexural strength, fracture toughness and maximum applicable firing temperature of ceramic samples of Examples 1-3 and Comparative Examples 1-2.

[0071] Results Analysis: The ceramic materials prepared in Examples 1-3 of this invention exhibit excellent and balanced comprehensive properties in terms of light-free self-cleaning, antibacterial properties, and mechanical properties. Specifically, in a completely dark environment, Examples 1-3 all achieved a degradation rate of over 40% for methylene blue after 24 hours (with Example 3 reaching as high as 68%), and the inhibition rates against Escherichia coli and Staphylococcus aureus all exceeded 99.0%. This fully demonstrates that the multi-component heterojunction structure constructed by rutile titanium dioxide, ferric oxide, and copper oxide successfully achieves a light-independent, non-photo-driven catalysis and highly efficient antibacterial mechanism. Comparative analysis showed that in Comparative Example 1, replacing rutile titanium dioxide with anatase titanium dioxide drastically reduced self-cleaning performance to 5%–20% and antibacterial rate to 50%–55%, confirming the decisive role of specific rutile crystal phases in achieving the anodized function. In Comparative Example 2, the simultaneous absence of ferric oxide and copper oxide significantly reduced self-cleaning performance (degradation rate only 15%–30%) and antibacterial rate below 45%, verifying the crucial role of these two components in constructing heterojunctions and synergistic catalysis. In Comparative Example 3, the absence of aluminum oxide and silicon dioxide maintained self-cleaning and antibacterial properties, but severely degraded mechanical properties (bending strength decreased to 58 MPa and fracture toughness decreased to 3.2 MPa·m).1 / 2 The maximum applicable firing temperature was reduced to 1180℃, which fully demonstrates the contribution of aluminum oxide and silicon dioxide to improving the mechanical strength of materials by promoting sintering densification.

[0072] Table 1. Test results of ceramic materials prepared in different embodiments and comparative examples.

[0073]

[0074] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A ceramic material with self-cleaning and antibacterial functions, characterized in that, It contains the following components by mass percentage: rutile titanium dioxide 4.0~4.5%, ferric oxide 3.0~4.0%, copper oxide 2.5~3.0%, zinc oxide 1.0~2.0%, aluminum oxide 5.0~6.0%, silicon dioxide 40~50%, kaolin 30~35%, magnesium oxide 2.0~2.5%, and calcium oxide 3.0~3.5%.

2. The ceramic material with self-cleaning and antibacterial functions according to claim 1, characterized in that, The mass ratio of rutile titanium dioxide, ferric oxide and copper oxide is (4.0~4.5): (3.0~4.0): (2.5~3.0).

3. The ceramic material with self-cleaning and antibacterial functions according to claim 1, characterized in that, The mass ratio of aluminum oxide to silicon dioxide is 1: (7.5~10.0).

4. The ceramic material with self-cleaning and antibacterial functions according to claim 1, characterized in that, It contains the following components by weight percentage: 4.2% rutile titanium dioxide, 3.5% ferric oxide, 2.8% copper oxide, 1.5% zinc oxide, 5.5% aluminum oxide, 45% silicon dioxide, 32% kaolin, 2.4% magnesium oxide, and 3.1% calcium oxide.

5. A method for preparing a ceramic material with self-cleaning and antibacterial functions as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Ingredients and mixing: Weigh each raw material according to the ratio, and ball mill and mix them with deionized water as the medium for 3~5 hours to obtain a uniform slurry with a particle size D50≤2μm; S2. Spray drying: The uniform slurry is spray dried to obtain a composite powder; S3. Molding: The composite powder is dry-pressed to obtain a blank with dimensions of 100mm×100mm×100mm; S4. Sintering: Sinter the green body for 1~3 hours to obtain the ceramic material.

6. The preparation method according to claim 5, characterized in that, The spray drying in step S2 is carried out under the conditions of an inlet air temperature of 160~200℃ and an outlet air temperature of 80~100℃.

7. The preparation method according to claim 5, characterized in that, The pressure for dry pressing in step S3 is 25~35MPa.

8. The preparation method according to claim 5, characterized in that, The heating rate for sintering in step S4 is 0.5~5℃ / min, and the sintering temperature is 1250~1350℃.

9. The application of a ceramic material with self-cleaning and antibacterial functions as described in any one of claims 1-4, characterized in that, Used to manufacture building tiles, tableware, or medical device components.

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