Preparation method of ceramic tea set based on novel nano-antibacterial material

Abstract

The invention belongs to the technical field of new materials and ceramic products, and particularly relates to a preparation method of a ceramic tea set based on a nano antibacterial new material, which comprises the following steps: preparing core-shell structure composite powder consisting of a nano metal oxide antibacterial core and a silicon dioxide inorganic shell layer; mixing with basic glaze to prepare functional glaze slip, and applying the functional glaze slip to a green body; after high-temperature sintering, the inorganic shell layer forms a diffusion shielding interface to protect the antibacterial core and is selectively dissolved in a weak acid environment of tea soup, controlled release of antibacterial ions is achieved, the dispersity and activity of the antibacterial phase are effectively maintained, and the broad-spectrum antibacterial efficiency and long-acting stability of the tea set are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of new materials and ceramic products technology, specifically a method for preparing ceramic teaware based on nano-antibacterial new materials. Background Technology

[0002] The increasing public awareness of health and the pursuit of a refined quality of life have driven antibacterial daily-use ceramic teaware to become an important direction for the high-end development and transformation of the ceramic industry. Existing technologies generally introduce inorganic antibacterial phases such as nano zinc oxide (ZnO) into ceramic glazes. The antibacterial effect is achieved by destroying the structure of microorganisms through the release of metal cations or active oxygen free radicals. Theoretically, this can achieve the goal of self-cleaning and antibacterial properties of the glaze. It has shown certain antibacterial efficacy in a normal temperature laboratory environment and has the potential for theoretical feasibility at this stage.

[0003] Existing nano-antibacterial solutions face irreconcilable structural contradictions in industrial transformation. The preparation of ceramic teaware requires high-temperature sintering at 1280℃ to 1320℃ to ensure structural strength and glaze texture. However, under high-temperature conditions, nano-ZnO becomes thermodynamically unstable and coarsens. It also reacts with SiO2 and Al2O3 in the glaze matrix to form inert zinc aluminum spinel (ZnAl2O4), resulting in a significant decrease in the activity of the antibacterial phase.

[0004] The failure of the antibacterial phase caused by high-temperature sintering results in the release concentration of active Zn²⁺ on the finished glaze surface being far below the effective antibacterial threshold of 10 ppm. In actual use, mild acidic tea soup cannot activate the inert antibacterial phase, rendering the antibacterial function ineffective. The core challenge is to protect the nano antibacterial phase, precisely control the slow release of antibacterial ions, and achieve in-situ activation while ensuring the quality of ceramic sintering.

[0005] Therefore, the present invention provides a method for preparing ceramic teaware based on novel nano-antibacterial materials. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0007] The technical solution adopted by this invention to solve its technical problem is: a method for preparing ceramic teaware based on novel nano-antibacterial materials, comprising the following steps:

[0008] Step 1: Prepare core-shell structured antibacterial nanocomposite powder, which consists of an antibacterial active core and an inorganic shell layer covering the surface of the antibacterial active core;

[0009] Step 2: Mix the core-shell structured nano antibacterial composite powder, the base glaze, and the dispersion medium in a preset ratio, and prepare a functional glaze slurry through a grinding process;

[0010] Step 3: Apply the functional glaze slurry to the surface of the ceramic body to form a functional layer to be sintered;

[0011] Step 4: Place the ceramic blank with the functional layer to be sintered in the sintering equipment and sinter it at high temperature according to the preset heating curve, so that the inorganic shell layer forms a diffusion shielding interface for the antibacterial active core in the glaze matrix. After cooling, the ceramic tea set is obtained.

[0012] Furthermore, the antibacterial active core is made of nano-metal oxide, which is a composite phase of zinc oxide and copper oxide.

[0013] Furthermore, the inorganic shell is made of silicon dioxide.

[0014] Furthermore, the inorganic shell layer is coated onto the surface of the antibacterial active core using a sol-gel process or a liquid phase deposition process, and the thickness of the inorganic shell layer is configured to a first preset distance.

[0015] Further, step one specifically includes: suspending the antibacterial active core in an alcohol-water mixed solution, adding a precursor solution and adjusting the system to a preset pH, so that the precursor grows in situ on the surface of the antibacterial active core through a hydrolysis-condensation reaction to form a continuous inorganic shell.

[0016] Furthermore, in step two, the mass ratio of the core-shell structured nano-antibacterial composite powder to the basic glaze is a preset ratio, and the fineness of the functional glaze slurry is controlled below a second preset value.

[0017] Furthermore, in step four, the preset sintering temperature is higher than the melting temperature of the base glaze, and the inorganic shell layer maintains its physical integrity at the preset sintering temperature to inhibit the solid-phase reaction between the antibacterial active core and the silicate component in the base glaze.

[0018] Furthermore, the glaze structure of the ceramic teaware is configured such that when it comes into contact with a tea medium in a preset acidic or alkaline environment, the inorganic shell layer undergoes selective dissolution, thereby achieving in-situ exposure of the antibacterial active core and controlled release of antibacterial ions.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. The present invention discloses a method for preparing ceramic teaware based on novel nano-antibacterial materials. This invention constructs a core-shell structured nano-antibacterial composite powder. The inorganic shell provides physical isolation and thermodynamic protection to the antibacterial active core during high-temperature sintering, effectively blocking the Ostwald ripening process between nanoparticles and the chemical recombination reaction with the glaze matrix, ensuring the high dispersion and chemical activity of the antibacterial phase in the glaze layer. Simultaneously, this structure achieves an in-situ activation mechanism for antibacterial ion release kinetics, that is, by selectively eroding the inorganic shell using the weakly acidic environment of the tea medium. This solves the problem of ion migration channel blockage caused by glaze densification in traditional antibacterial ceramics, significantly improving the broad-spectrum antibacterial efficacy and long-term stability of the ceramic teaware under actual service conditions. Attached Figure Description

[0021] The invention will now be further described with reference to the accompanying drawings.

[0022] Figure 1 This is a flowchart of a method for preparing ceramic teaware based on novel nano-antibacterial materials in this invention. Detailed Implementation

[0023] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0024] like Figure 1 As shown in the embodiment of the present invention, a method for preparing ceramic teaware based on novel nano-antibacterial materials is presented. This method systematically solves the core technical contradictions that easily occur in the nanoscale antibacterial phase under high-temperature sintering conditions of ceramics, such as grain growth, chemical component diffusion and deactivation to the glaze surface, and the inability of antibacterial ions to migrate to the surface after glaze densification, by constructing a core-shell structure with specific physical barrier functions. In the specific process implementation, the preparation logic of the core-shell structure nano-antibacterial composite powder is first precisely controlled to ensure that the antibacterial active core remains in a thermodynamically stable state during subsequent high-temperature heat treatment.

[0025] In the initial stage of preparing core-shell structured antibacterial nanocomposite powders, the core construction logic lies in selecting nano-metal oxides with highly efficient and broad-spectrum antibacterial capabilities as the antibacterial active core. In engineering practice, although zinc oxide or copper oxide alone possesses certain antibacterial properties, when dealing with the complex chemical environment of teaware (such as tea polyphenols, alkaloids, etc.), the antibacterial rate and broad-spectrum activity of a single component are often difficult to achieve optimal results. Therefore, this invention preferably uses a composite phase of zinc oxide and copper oxide as the antibacterial active core. The construction of this composite phase is not a simple physical mixing, but rather a microscopic heterostructure formed through co-precipitation or pyrolysis. It utilizes the difference in semiconductor band gradients to enhance electron migration efficiency under weak light or no-light conditions, thereby increasing the generation rate of reactive oxygen species.

[0026] To enable the aforementioned antibacterial active core to withstand the high-temperature impact exceeding 1000 degrees Celsius in subsequent stages, a dense inorganic shell layer must be grown in situ on the surface of the antibacterial active core. In the specific engineering implementation, the material of the inorganic shell layer is set as silicon dioxide. The logic for choosing silicon dioxide lies in its excellent thermal stability and compatibility with the silicate components in traditional ceramic base glazes. In the specific coating process logic, a sol-gel process is used to uniformly suspend the antibacterial active core in an alcohol-water mixture solution. Here, the alcohol-water mixture solution is usually prepared by mixing ethanol and deionized water in a specific ratio, and its function is to adjust the dielectric constant of the system to ensure that the hydrolysis rate of the precursor molecules is controlled. Subsequently, silicate ester compounds as precursor solutions are slowly added to the system, and the pH of the system is precisely adjusted to a preset pH by adding an alkaline catalyst (such as ammonia), usually maintained in the weakly alkaline range. Under this acid-base environment, the silicate ester precursor undergoes a hydrolysis reaction to generate silica monomers, which then undergo a condensation reaction on the surface of the antibacterial active core. By controlling the concentration of the precursor solution, the dropping rate, and the reaction time, a continuous inorganic shell with a thickness of a first preset distance can be grown on the surface of the antibacterial active core. The setting of this first preset distance is crucial; if the thickness is insufficient, it will be unable to effectively prevent ion interdiffusion at high temperatures; if the thickness is too large, it will increase the difficulty of subsequent erosion of the inorganic shell by the tea infusion medium. Typically, this first preset distance is controlled between ten and fifty nanometers to achieve the optimal balance between protective efficacy and activation efficiency.

[0027] After preparing the core-shell structured antibacterial nanocomposite powder, the next step is to formulate the functional glaze slurry. The engineering logic of this step is to uniformly introduce the core-shell structured antibacterial nanocomposite powder as a functional additive phase into the base glaze system. The base glaze typically contains feldspar, quartz, kaolin, and flux components. During the mixing process, the mass ratio of the core-shell structured antibacterial nanocomposite powder to the base glaze must strictly adhere to a preset ratio. If the proportion of the core-shell structured antibacterial nanocomposite powder is too low, a sufficient effective antibacterial concentration cannot be formed on the glaze surface; if the proportion is too high, it may disrupt the expansion coefficient matching of the glaze surface, leading to glaze cracking or peeling. During the mixing process, a dispersion medium (usually deionized water with a small amount of organic dispersant) is introduced, and grinding is performed using a high-energy ball mill. The control objective of the grinding process is to control the fineness of the functional glaze slurry below a second preset value. This second preset value typically refers to the percentage of residue passing through a 325-mesh sieve. The technical purpose of controlling the fineness is to ensure that the core-shell structured nano-antibacterial composite powder is highly deagglomerated in the glaze slurry, preventing it from existing in the form of agglomerates, thereby forming a uniform distribution network in the sintered glaze layer.

[0028] Subsequently, the functional glaze is applied to the surface of the ceramic body. The glazing process can employ methods such as dipping, spraying, or pouring to form the functional layer to be sintered. During the glazing process, it is essential to maintain the uniformity of the thickness of the functional layer to be sintered. This layer exists not only to provide antibacterial properties but also to form a good intermediate bonding layer with the body during sintering.

[0029] The most crucial step lies in the logical control of the sintering process. The ceramic blank with the functional layer to be sintered is placed in the sintering equipment and sintered at high temperature according to a preset heating curve. During the heating process, the system undergoes water evaporation, organic matter oxidation and decomposition, mineral dehydration, and finally, eutectic melting. When the temperature rises to the preset sintering temperature (usually higher than the melting temperature of the base glaze), the base glaze transforms into a liquid phase. At this point, the silica inorganic shell layer of the core-shell structured nano-antibacterial composite powder exhibits extremely high physical integrity. This inorganic shell layer forms a microscopic diffusion shielding interface at high temperatures, effectively isolating the internal zinc oxide and copper oxide composite phases. This logic solves two deep-seated engineering problems: first, it prevents the nanoscale antibacterial active core from undergoing Ostwald ripening in the liquid phase environment, i.e., avoiding grain coarsening caused by large particles engulfing small particles, thus maintaining its high specific surface area; second, it inhibits the solid-phase reaction between the antibacterial active core and the silicate and aluminate components in the base glaze to generate non-antibacterial zinc silicate or copper aluminate.

[0030] During the cooling stage after sintering, the silica inorganic shell layer, due to its similar chemical affinity to the base glaze, can be stably anchored within the glaze matrix. Under normal conditions, the antibacterial phase of the prepared ceramic teaware is encapsulated within the inorganic shell layer, exhibiting extremely high chemical stability. Another core control logic of this invention lies in the "on-demand release" of the antibacterial function. When the ceramic teaware comes into contact with a tea infusion medium in a pre-set acidic or alkaline environment (tea infusion is typically weakly acidic and contains various complexing ligands), the inorganic shell layer selectively dissolves. Since the thickness of the inorganic shell layer is pre-set at the micro-nano level, the weakly acidic tea infusion environment can slowly erode this thin protective film, exposing the internal antibacterial active core in situ. Subsequently, zinc oxide and copper oxide release zinc and copper ions in the aqueous environment. These ions migrate to the surface through the fine diffusion channels in the glaze layer, thereby achieving a broad-spectrum bactericidal effect. This design logic cleverly solves the problem of "dead medicine" caused by traditional ceramic antibacterial agents being completely encapsulated by a dense glaze layer, ensuring the antibacterial continuity of teaware during long-term use.

[0031] Through the aforementioned complete logical chain, this invention not only achieves the survival of the antibacterial phase under extreme preparation environments, but also endows the teaware with intelligent responsive characteristics through ingenious microstructure design. The following specific embodiments and comparative examples provide data-driven verification of the technical parameters, implementation process, and technical effects of this invention.

[0032] Example 1

[0033] In Example 1, the preparation process of a high-proportion zinc oxide composite system is explored. First, a core-shell structured nano-antibacterial composite powder is prepared. Zinc oxide powder with an average particle size of 20 nanometers and copper oxide powder with an average particle size of 15 nanometers are selected and composited at a mass ratio of 4:1 to obtain an antibacterial active core. This antibacterial active core is placed in a solution with a volume ratio of ethanol to water of 5:1 and ultrasonically dispersed for 30 minutes to ensure no particle agglomeration. Subsequently, 10 ml of tetraethyl orthosilicate is added per 100 ml of suspension, with the dropping rate controlled at 1 ml per minute. The pH of the system is adjusted to 8.5. The reaction is stirred at room temperature for 6 hours, resulting in the formation of an inorganic shell layer of approximately 15 nanometers thickness on the surface of the antibacterial active core with silica. In the preparation of the functional glaze slurry, the core-shell structured nano-antibacterial composite powder is mixed with the base glaze at a mass ratio of 3:97. The base glaze is a feldspar glaze. Deionized water was added as the dispersion medium, and the mixture was ground in a ball mill for eight hours. The fineness of the functional glaze slurry was measured to be 0.1% residue after passing through a 325-mesh sieve. After glazing, the ceramic body was placed in an electric kiln. The preset heating curve was as follows: the temperature was increased to 600 degrees Celsius at a rate of 5 degrees Celsius per minute and held for one hour to remove structural water; then the temperature was increased to 1230 degrees Celsius at a rate of 8 degrees Celsius per minute and held for 30 minutes. After cooling, the ceramic teaware sample of Example 1 was obtained.

[0034] Example 2

[0035] In Example 2, the focus was on increasing the thickness of the inorganic shell and adjusting the sintering temperature. The antibacterial active core was a composite phase of zinc oxide and copper oxide in a 1:1 mass ratio. This antibacterial active core was suspended in an alcohol-water mixture. During the coating stage, the amount of tetraethyl orthosilicate added was increased to raise the precursor concentration by 50%, and the reaction time was extended to ten hours. The final inorganic shell thickness was approximately 35 nanometers. When preparing the functional glaze slurry, the mass ratio of the core-shell structured nano-antibacterial composite powder to the base glaze was set to 5:95. The base glaze was a lime-alkali glaze system. The fineness of the ground functional glaze slurry was controlled to below 0.05%. During the sintering stage, the highest preset sintering temperature was increased to 1280 degrees Celsius, and the holding time was extended to 40 minutes. This process was designed to verify the protective efficacy of a thicker inorganic shell for the internal active core under high sintering strength. After cooling, the ceramic teaware sample of Example 2 was obtained.

[0036] Example 3

[0037] In Example 3, an inorganic shell layer was prepared using liquid phase deposition. The antibacterial active core was a composite phase of zinc oxide and copper oxide in a 2:1 mass ratio. The antibacterial active core was placed in a mixed solution containing fluorosilicic acid and boric acid, and a continuous silica film was slowly deposited on the surface of the antibacterial active core using the principle of liquid phase deposition. The deposition temperature was controlled at 40 degrees Celsius for 12 hours, resulting in an inorganic shell layer with a thickness of approximately 25 nanometers. The above powder was mixed with the base glaze at a mass ratio of 4:96. The fineness of the functional glaze slurry was controlled to 0.08%. A rapid firing process was used for sintering, with a heating rate set at 15 degrees Celsius per minute, a maximum temperature of 1210 degrees Celsius, and a holding time shortened to 15 minutes. After cooling, the ceramic teaware sample of Example 3 was obtained.

[0038] Comparative Example 1

[0039] Comparative Example 1 served as a blank control group, using ordinary feldspar glaze completely free of antibacterial components, prepared according to the sintering curve of Example 1. Its purpose was to provide a baseline reference for the basic antibacterial level of ceramic teaware (theoretically, it should have no significant antibacterial properties).

[0040] Comparative Example 2

[0041] Comparative Example 2 aims to verify the necessity of the "core-shell structure." Zinc oxide and copper oxide composite powders (without silica coating) in the same proportions as in Example 1 were directly added to the base glaze at a mass ratio of 3:97. Subsequent grinding, glazing, and sintering processes were completely consistent with Example 1. This control group was used to observe whether unprotected nanoparticles would lose their antibacterial efficacy during high-temperature sintering due to solid-phase reactions or grain coarsening.

[0042] Comparative Example 3

[0043] Comparative Example 3 aims to verify the impact of the "silica shell" on the controlled ion release logic. Silver nanoparticles were used instead of the zinc oxide / copper oxide composite phase of this invention, and the silica was coated using the same sol-gel method. Since silver is readily oxidized and diffuses at high temperatures, and its ion release mechanism differs from that of transition metal oxides, this verifies the superiority of the specific material combination of this invention. The remaining steps are consistent with Example 1.

[0044] To quantitatively verify the technical effects of the above embodiments and comparative examples, we conducted bactericidal rate tests against Escherichia coli and Staphylococcus aureus (following national standard testing procedures) and simulated the long-term antibacterial performance under a real tea water environment (weakly acidic, pH approximately 5.5). The testing period was divided into immediate testing after sintering and performance testing simulating one year of use.

[0045] The data test results are shown in the table below:

[0046] Group Name Initial E. coli sterilization rate (%) Initial Staphylococcus aureus sterilization rate (%) Sterilization rate (%) after one year of simulated use Microscopic observation of the glaze surface (scanning electron microscope) Example 1 99.92 99.85 99.20 The antibacterial phase particles are uniform, without obvious coarsening, and the core-shell interface is clear. Example 2 99.95 99.90 99.55 The shell is intact, and the antibacterial phase is extremely well protected. Example 3 99.88 99.80 98.95 The glaze is dense and the antibacterial phase is highly dispersed. Comparative Example 1 12.50 10.20 5.30 No antibacterial characteristic phase Comparative Example 2 45.30 42.10 15.60 The particles are severely coarsened, and obvious zinc silicate crystals appear. Comparative Example 3 82.10 79.50 35.40 A significant loss of silver ions caused a change in the color of the glaze.

[0047] The above data analysis clearly leads to the following conclusions: Examples 1 to 3 all exhibited extremely high initial antibacterial efficacy, with sterilization rates exceeding 99%. More importantly, after one year of simulated use, the antibacterial performance of these examples remained above 98%. This demonstrates that the inorganic shell layer in the core-shell structure played a decisive protective role during sintering, successfully preventing the chemical deactivation of the antibacterial active core. Simultaneously, the selective dissolution mechanism of the silica shell layer in the tea infusion medium ensured the long-term controlled release of antibacterial ions.

[0048] In contrast, Comparative Example 2, lacking the protection of an inorganic shell, had an initial antibacterial rate of only about 45%. Microstructural analysis revealed that the uncoated nano-zinc oxide underwent a violent solid-phase reaction with the silica in the glaze at a high temperature of 1200 degrees Celsius, generating a zinc silicate phase lacking antibacterial ability, resulting in the complete loss of active ingredients. Furthermore, due to the absence of a core-shell structure, the nanoparticles experienced severe welding and coarsening, significantly reducing their chemical activity.

[0049] Although Comparative Example 3 initially exhibited some antibacterial activity, its bactericidal rate significantly decreased after one year of simulated use due to the rapid release of silver ions and the lack of a selective response mechanism to acidic and alkaline environments. This further demonstrates that the combination of the zinc oxide / copper oxide composite phase and the silica core-shell structure employed in this invention has irreplaceable technical advantages in the specific application scenario of ceramic teaware, solving not only the survival problem during high-temperature sintering but also the durability problem during service.

[0050] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing ceramic teaware based on novel nano-antibacterial materials, characterized in that, Includes the following steps: Step 1: Prepare core-shell structured antibacterial composite powder, which consists of an antibacterial active core and an inorganic shell layer covering the surface of the antibacterial active core; Step 2: Mix the core-shell structured antibacterial composite powder, the base glaze, and the dispersion medium in a preset ratio, and prepare a functional glaze slurry through a grinding process; Step 3: Apply the functional glaze slurry to the surface of the ceramic body to form a functional layer to be sintered; Step 4: Place the ceramic blank with the functional layer to be sintered in a sintering device and perform high-temperature sintering according to a preset heating curve, so that the inorganic shell layer forms a diffusion shielding interface for the antibacterial active core in the glaze matrix. After cooling, the ceramic tea set is obtained.

2. The method for preparing a ceramic teaware based on antibacterial materials according to claim 1, characterized in that, The antibacterial active core in the core-shell structured antibacterial composite powder is a metal oxide, which is a composite phase of zinc oxide and copper oxide.

3. The method for preparing ceramic teaware based on antibacterial materials according to claim 1, characterized in that, The inorganic shell in the core-shell structured antibacterial composite powder is made of silicon dioxide.

4. The method for preparing a ceramic teaware based on antibacterial materials according to claim 1, characterized in that, The inorganic shell layer in the core-shell structured antibacterial composite powder is coated onto the surface of the antibacterial active core by a sol-gel process or a liquid phase deposition process, and the thickness of the inorganic shell layer is configured to a first preset distance.

5. The method for preparing a ceramic teaware based on antibacterial materials according to claim 4, characterized in that, Step one specifically includes: suspending the antibacterial active core in an alcohol-water mixed solution, adding a precursor solution and adjusting the system to a preset pH, so that the precursor grows in situ on the surface of the antibacterial active core through a hydrolysis-condensation reaction to form a continuous inorganic shell.

6. The method for preparing a ceramic teaware based on antibacterial materials according to claim 1, characterized in that, In step two, the mass ratio of the core-shell structured antibacterial composite powder to the base glaze is a preset ratio, and the functional glaze slurry includes a dispersion medium and additives. The fineness of the functional glaze slurry is controlled below a second preset value, which is defined as the percentage of residue after passing through a 325-mesh sieve.

7. The method for preparing a ceramic teaware based on antibacterial materials according to claim 1, characterized in that, The preset sintering temperature in step four is higher than the melting temperature of the base glaze, and the inorganic shell layer maintains its physical integrity at the preset sintering temperature to inhibit the solid-phase reaction between the antibacterial active core and the silicate component in the base glaze.

8. The method for preparing a ceramic teaware based on antibacterial materials according to claim 1, characterized in that, The glaze structure of the ceramic teaware is configured such that when it comes into contact with a liquid medium in a preset acidic or alkaline environment, the inorganic shell layer undergoes selective dissolution, thereby achieving in-situ exposure of the antibacterial active core and controlled release of antibacterial ions.

9. The method for preparing a ceramic teaware based on antibacterial materials according to claim 4, characterized in that, The first preset distance is configured as a value between ten and fifty length references, so that the inorganic shell can have high-temperature protection performance while satisfying the solubility in a weakly acidic environment.

10. A ceramic tea set, characterized in that, The ceramic teaware is prepared by the method according to any one of claims 1 to 9, and the surface of the ceramic teaware has a glaze layer containing core-shell structured antibacterial composite powder, wherein the inorganic shell layer in the core-shell structured antibacterial composite powder forms a protective barrier against the internal antibacterial active core in the glaze layer.

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