Hydrophilic self-cleaning archaized brick and preparation method thereof

Abstract

The invention relates to the technical field of architectural ceramics, in particular to a hydrophilic self-cleaning archaized brick and a preparation method thereof.The preparation method comprises the following steps that A, a ceramic blank is prepared, pressed and dried to obtain a blank with the concave-convex effect on the surface; b, preparing hydrophilic self-cleaning glaze; c, applying hydrophilic self-cleaning glaze to the surface of the green body to form a hydrophilic self-cleaning glaze layer; and D, drying and calcining in a kiln to obtain the hydrophilic self-cleaning archaized brick. According to the preparation method of the hydrophilic self-cleaning archaized brick, the preparation method is simple and high in operability, and the obtained hydrophilic self-cleaning archaized brick not only has excellent and lasting hydrophilic self-cleaning performance, but also has excellent and lasting antibacterial performance on the premise that the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of building ceramics technology, and in particular to a hydrophilic self-cleaning antique-style brick and its preparation method. Background Technology

[0002] Antique-style bricks, as an artistic building material that blends classical aesthetics with modern craftsmanship, are highly favored by consumers for their unique antique glaze effect, rich color layers, and strong historical charm. They are widely used in home decoration, commercial venues, and cultural tourism scenic spots.

[0003] To ensure the antique effect of antique-style bricks, their surfaces are usually designed to be uneven. While this uneven surface increases their anti-slip properties, it also easily accumulates dust, oil stains, and other dirt. Ordinary wiping is insufficient for thorough cleaning, and long-term accumulation not only affects the appearance but may also breed bacteria. Traditional cleaning methods typically rely on chemical cleaners or high-pressure water guns, which are not only inefficient but may also cause wear or corrosion to the brick surface.

[0004] To overcome the above-mentioned defects, existing technologies typically coat the surface of antique bricks with a hydrophilic self-cleaning coating, forming a hydrophilic self-cleaning coating on the surface of the antique bricks. This allows water to spread rapidly when it comes into contact with the coating surface (i.e., the static contact angle between water and the coating is small) and form a uniform water film. The water film can penetrate into the interface between dirt and the coating, thereby reducing the adhesion of dirt. Furthermore, under the action of gravity, the continuously flowing water film can carry away and remove dirt from the surface of the antique bricks, achieving the effect of hydrophilic self-cleaning. However, the above methods have the following drawbacks: (1) The hydrophilic self-cleaning coating has poor aging resistance. It is prone to aging when exposed to ultraviolet rays, rain and temperature changes for a long time, which leads to the gradual failure of the hydrophilic self-cleaning function and poor hydrophilic self-cleaning durability; (2) The hydrophilic self-cleaning coating has limited bonding force with the antique brick substrate. It is easy to peel off under frequent friction or temperature stress, which will also reduce the durability of hydrophilic self-cleaning; (3) The surface of existing antique bricks generally does not have hydrophilic self-cleaning properties. It is necessary to apply an additional layer of hydrophilic self-cleaning coating to make it have hydrophilic self-cleaning properties. However, applying an additional hydrophilic self-cleaning coating will easily increase production costs and is not conducive to large-scale promotion and application.

[0005] Therefore, how to achieve durable hydrophilic self-cleaning properties while reducing production costs has become an urgent technical challenge. Summary of the Invention

[0006] The primary objective of this invention is to provide a method for preparing hydrophilic self-cleaning antique-style bricks. The method is simple and easy to operate. The resulting hydrophilic self-cleaning antique-style bricks not only have excellent and long-lasting hydrophilic self-cleaning properties, but also excellent and long-lasting antibacterial properties, while reducing production costs.

[0007] The second objective of this invention is to provide a method for preparing hydrophilic self-cleaning antique-style bricks. The resulting hydrophilic self-cleaning antique-style bricks have a static contact angle of 2–7° before being soaked in boiling water, and a static contact angle of 9–15° after being soaked in boiling water for 30 days. They exhibit an antibacterial rate of ≥98.3% against Escherichia coli, an antibacterial rate of ≥98.5% against Staphylococcus aureus, an antibacterial durability of ≥88.1% against Escherichia coli, and an antibacterial durability of ≥87.6% against Staphylococcus aureus. They possess not only excellent and long-lasting hydrophilic self-cleaning properties but also excellent and long-lasting antibacterial performance.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] A method for preparing hydrophilic self-cleaning antique-style bricks includes the following steps:

[0010] A. Prepare ceramic blanks, press the ceramic blanks, and dry them to obtain blanks with a textured surface.

[0011] B. Prepare hydrophilic self-cleaning glaze;

[0012] According to mass fractions, the raw materials of the hydrophilic self-cleaning glaze include 42-52 parts of hydrophilic frit, 3-9 parts of nano-anatase titanium dioxide, 18-30 parts of quartz, 10-18 parts of calcite, 3-7 parts of nano-zinc oxide, and 2-6 parts of nano-bovine bone ash, and the chemical composition of the nano-bovine bone ash includes Ca. 10 (PO4)6(OH)2 and CaO;

[0013] According to the mass fractions, the raw materials of the hydrophilic frit include 15-19 parts of calcite, 15-19 parts of wollastonite, 32-52 parts of kaolin, 15-19 parts of alumina and 5-11 parts of quartz.

[0014] C. Apply the hydrophilic self-cleaning glaze to the surface of the body to form a hydrophilic self-cleaning glaze layer;

[0015] D. After drying, the bricks are fired in a kiln to obtain hydrophilic self-cleaning antique-style bricks.

[0016] Furthermore, in step B, the particle size of the nano-anatase phase titanium dioxide, the nano-zinc oxide, and the nano-bovine bone ash is all <20nm.

[0017] Further, in step B, the chemical composition of the nano-bovine bone ash, calculated by mass percentage, includes Ca. 10 (PO4)6(OH)2 60-75%, CaO 15-25%, MgO 5-8%, Na2O 3-5%, and K2O 1-2%.

[0018] Further, in step B, the hydrophilic self-cleaning glaze, calculated by mass percentage, leaves a residue of 0.2-0.4% after passing through a 325-mesh sieve.

[0019] Furthermore, in step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.15 to 1.2.

[0020] Further, in step B, the calcination temperature curve of the hydrophilic frit is as follows: the temperature is increased from room temperature to 1530°C at a heating rate of 8-10°C / min, and then held for 35-45 minutes.

[0021] Furthermore, in step B, the preparation steps for the hydrophilic self-cleaning glaze are as follows:

[0022] The raw materials for the hydrophilic frit are mixed evenly according to the formula, calcined, and then water-quenched to obtain the hydrophilic frit;

[0023] After mixing the raw materials of the hydrophilic self-cleaning glaze evenly according to the formula, sodium methyl cellulose, sodium hexametaphosphate and water are added and ball-milled, and then sieved to obtain the hydrophilic self-cleaning glaze; wherein, according to the mass percentage, the amount of water added is 33 to 50% of the dry material of the hydrophilic self-cleaning glaze.

[0024] Furthermore, in step C, the thickness of the hydrophilic self-cleaning glaze is 0.05–0.1 mm.

[0025] Furthermore, in step D, the firing temperature curve of the hydrophilic self-cleaning antique brick includes a preheating section, a preheating section, a high-temperature section, a heat preservation section, a transition section, a rapid cooling section, a slow cooling section, a strong cooling section, and a final cooling section.

[0026] The preheating section takes 3 to 6 minutes to raise the temperature from room temperature to 750°C.

[0027] The temperature rises from 750°C to 1050°C in the initial temperature range, taking 1.2 to 4 minutes.

[0028] The high-temperature section rises from 1050℃ to 1145℃ in 5–8 minutes;

[0029] The insulation section is maintained at 1145℃ for 4.5–10 minutes.

[0030] The transition section cools the temperature from 1145℃ to 950℃ in 1.8–5 minutes.

[0031] The rapid cooling section reduces the temperature from 950°C to 630°C in 2–3 minutes.

[0032] The slow cooling section reduces the temperature from 630°C to 610°C in 5–10 minutes.

[0033] The rapid cooling section reduces the temperature from 610°C to 210°C in 3.5–6 minutes.

[0034] The final cooling section cools the temperature from 310°C to 200°C in 4–8 minutes.

[0035] A hydrophilic self-cleaning antique-style brick is prepared using the above-mentioned method. The static contact angle of the hydrophilic self-cleaning antique-style brick without soaking in boiling water is 2-7°, and the static contact angle after soaking in boiling water for 30 days is 9-15°. The antibacterial rate against Escherichia coli is ≥98.3%, the antibacterial rate against Staphylococcus aureus is ≥98.5%, the antibacterial durability against Escherichia coli is ≥88.1%, and the antibacterial durability against Staphylococcus aureus is ≥87.6%.

[0036] The technical solution provided by this invention may include the following beneficial effects:

[0037] 1. This technical solution forms a micro-nano rough structure through multiple mechanisms. This micro-nano rough structure significantly increases the microscopic roughness of the hydrophilic self-cleaning glaze surface, thereby increasing its actual specific surface area. The increased specific surface area exposes more surface atoms or molecules. These surface atoms or molecules, due to the presence of unsaturated chemical bonds (such as dangling bonds), are in a high-energy unstable state. The accumulation of high-energy surface atoms can increase the surface energy of the glaze. Simultaneously, the micro-nano rough structure increases the local curvature of the hydrophilic self-cleaning glaze surface, raising the chemical potential of surface atoms, which is beneficial for improving the surface energy of the hydrophilic self-cleaning glaze.

[0038] 2. Through the synergistic effect of the above-mentioned multiple aspects, this technical solution enriches the surface of the hydrophilic self-cleaning glaze with hydroxyl groups, strengthens the hydrogen bond adsorption capacity between the hydrophilic self-cleaning glaze and water molecules, improves the hydrophilicity of the surface of the hydrophilic self-cleaning glaze, and makes it easier for water to spread on the glaze surface and form a uniform water film, thereby removing and cleaning the dirt on the surface of the antique brick, thus improving the hydrophilic self-cleaning performance.

[0039] 3. The nano-anatase phase titanium dioxide in this technical solution can also generate electron-hole pairs (e-hole pairs) under ultraviolet light excitation. - -h + Electron-hole pairs (e - -h + It can react with water vapor and / or oxygen in the air to generate substances such as hydroxyl radicals, superoxide radicals, and hydrogen peroxide. The reactive oxygen species in these substances can oxidize lipids, proteins, and nucleic acids in bacterial cells, leading to apoptosis. Simultaneously, nano-anatase titanium dioxide can continuously generate electron-hole pairs with antibacterial activity under photocatalysis, thus achieving a long-lasting antibacterial effect.

[0040] 4. The micro-nano rough structure and micro-nano porous structure of the glaze are beneficial to improving antibacterial properties. The specific principles are as follows: (1) The micro-nano rough structure and micro-nano porous structure of the glaze greatly increase its specific surface area, so that antibacterial components (such as titanium ions, zinc oxide, etc.) can be more fully exposed on the glaze, thereby providing more abundant reactive sites. The increase of the above-mentioned reactive sites enables antibacterial components to come into contact with bacteria more efficiently and trigger reactions, thereby accelerating the killing or growth inhibition process of bacteria. (2) The sharp edges of the micro-nano rough structure and micro-nano porous structure can directly pierce the cell wall or biofilm of bacteria when in contact with bacteria, causing physical damage to bacteria, thus providing additional protection for the antibacterial properties of the glaze; (3) The micro-nano rough structure and micro-nano porous structure of the glaze are also conducive to the effective diffusion of oxygen and moisture, promoting the reaction of antibacterial components with water vapor and / or oxygen in the air, generating more hydroxyl radicals, superoxide radicals and hydrogen peroxide and other active substances with strong oxidizing properties. The increased amount of the aforementioned active substances further enhances the antibacterial properties of the glaze. Detailed Implementation

[0041] This technical solution provides a method for preparing hydrophilic self-cleaning antique-style bricks, including the following steps:

[0042] A. Prepare ceramic blanks, press the ceramic blanks, and dry them to obtain blanks with a textured surface.

[0043] B. Prepare hydrophilic self-cleaning glaze;

[0044] According to mass fractions, the raw materials of the hydrophilic self-cleaning glaze include 42-52 parts of hydrophilic frit, 3-9 parts of nano-anatase titanium dioxide, 18-30 parts of quartz, 10-18 parts of calcite, 3-7 parts of nano-zinc oxide, and 2-6 parts of nano-bovine bone ash, and the chemical composition of the nano-bovine bone ash includes Ca. 10 (PO4)6(OH)2 and CaO;

[0045] According to the mass fractions, the raw materials of the hydrophilic frit include 15-19 parts of calcite, 15-19 parts of wollastonite, 32-52 parts of kaolin, 15-19 parts of alumina and 5-11 parts of quartz.

[0046] C. Apply the hydrophilic self-cleaning glaze to the surface of the body to form a hydrophilic self-cleaning glaze layer;

[0047] D. After drying, the bricks are fired in a kiln to obtain hydrophilic self-cleaning antique-style bricks.

[0048] To achieve durable hydrophilic self-cleaning properties while reducing costs, this technical solution proposes a hydrophilic self-cleaning glaze. Its raw materials include hydrophilic frit, nano-anatase titanium dioxide, quartz, calcium carbonate, nano-zinc oxide, and nano-bovine bone ash. The frit itself comprises calcite, wollastonite, kaolin, alumina, and quartz. It should be noted that the green body in this solution is formed by pressing and drying conventional ceramic green bodies; further description of the ceramic green body is omitted here.

[0049] First, during the calcination process, a series of chemical reactions occur in the raw materials of the formula system: calcite (mainly calcium carbonate) decomposes to generate calcium oxide; wollastonite (chemically calcium metasilicate) decomposes to generate calcium oxide and silicon dioxide; kaolin decomposes to generate silicon dioxide and aluminum oxide. The combined effects of these reaction products, along with the introduction of silicon dioxide by quartz, calcium oxide by nano-bone ash, and the aluminum oxide, zinc oxide, and titanium dioxide already present in the formula system, result in a hydrophilic self-cleaning glaze layer formed after calcination, primarily composed of calcium oxide, silicon dioxide, aluminum oxide, zinc oxide, and titanium dioxide. This is because calcium oxide (with a surface tension of 470 × 10⁻⁶)... -3 N / M), silica (surface tension of 290×10 -3 N / M), aluminum oxide (surface tension 380×10 -3 N / M), zinc oxide (surface tension 500×10 -3 N / M) and titanium dioxide (surface tension of 400×10 -3 The surface tension of N / M is much greater than that of water (surface tension is 73×10). -3 The surface tension (i.e., surface energy) of the hydrophilic self-cleaning glaze is significantly higher than that of water (N / m), thus endowing the hydrophilic self-cleaning glaze with higher surface energy. It should be noted that for the description of the surface properties of liquids and solids, liquids are generally described using surface tension, while solids are generally described using surface energy. Therefore, in the following description, the surface tension of the glaze layer will be described using surface energy.

[0050] Furthermore, in this technical solution's formulation system, the calcium oxide, aluminum oxide, and silicon dioxide introduced by the calcination of the raw materials react to form anorthite crystals (CaAl2Si2O8), while aluminum oxide and silicon dioxide can react to form mullite (3Al2O3·2SiO2). During the precipitation process, due to anisotropic growth and the presence of dislocation defects, some of these crystals exist in the form of microcrystals. The precipitated microcrystals are usually irregular in shape, such as polyhedra, needles, and plates. When these irregularly shaped microcrystals precipitate from the glaze glass phase (matrix), they form a micro-nano rough structure on the glaze surface.

[0051] Furthermore, due to its small particle size and large specific surface area, nano-bovine bone ash possesses high surface energy. This high surface energy drives its spontaneous adsorption and accumulation on the glaze surface. Since the decomposition initiation temperature of nano-bovine bone ash is approximately 1400℃, and the calcination temperature in existing kilns is generally below 1200℃, even if the formulation contains fluxes such as zinc oxide to promote its melting, only partial decomposition occurs. The skeletal structure of its nanoparticles is preserved, forming a micro-nano rough structure on the glaze surface.

[0052] In summary, this technical solution creates a micro-nano rough structure through multiple mechanisms. This micro-nano rough structure significantly increases the micro-roughness of the hydrophilic self-cleaning glaze surface, thereby increasing its actual specific surface area. The increased specific surface area exposes more surface atoms or molecules. These surface atoms or molecules, due to the presence of unsaturated chemical bonds (such as dangling bonds), are in a high-energy unstable state. The accumulation of these high-energy surface atoms enhances the surface energy of the glaze. Simultaneously, the micro-nano rough structure increases the local curvature of the hydrophilic self-cleaning glaze surface, raising the chemical potential of surface atoms and further improving the surface energy. It should be noted that only the micro-nano rough structure exhibiting a microscopic structure can affect the surface energy of the glaze. The millimeter- or even centimeter-level unevenness on the surface of antique-style tiles is a macroscopic scale that only affects the mechanical anti-slip properties of the tile and does not alter the chemical properties of the glaze surface. In addition, even though millimeter- or centimeter-level embossing effects may contain ordinary micro-rough structures, these micro-rough structures are generally unlikely to reach the critical scale of "significant increase in local curvature". This means that the contribution of these ordinary micro-roughness to surface energy may be limited, and millimeter-level embossing textures still mainly affect the mechanical anti-slip properties of the brick.

[0053] Furthermore, during calcination, calcite not only decomposes to form calcium oxide but also releases carbon dioxide gas. Under the current firing cycle of 30–60 minutes in kilns, the escaped carbon dioxide gas leaves behind submicron-sized pores, forming a micro / nano porous structure. This micro / nano porous structure significantly increases the actual surface area of ​​the glaze, which also helps to improve the surface energy of the glaze.

[0054] In summary, through the aforementioned multiple effects, the hydrophilic self-cleaning glaze layer is endowed with a high surface energy, making it easier for water to spread on its surface and form a uniform water film. This water film can carry away and remove dirt from the surface of the antique-style tiles, thus achieving the hydrophilic self-cleaning performance.

[0055] Secondly, calcium oxide is composed of calcium ions (Ca... 2+ ) and oxygen ions (O 2-Ionic compounds formed by ionic bonds readily react with moisture (such as ambient water vapor adsorbed on the surface of raw materials, crystal water bound between glaze components, or moisture introduced during the process) to generate calcium hydroxide (CaO+H2O→Ca(OH)2). The surface of calcium hydroxide contains a large number of highly polar hydroxyl groups.

[0056] Simultaneously, acidic oxides (such as silicon dioxide) in the formulation system react with basic oxides (such as calcium oxide and zinc oxide) to form a silicate network structure (i.e., a glassy phase). The alkali metal ions provided by the alkali metal oxides (such as calcium oxide and zinc oxide) can break the bridging oxygen bonds between silicon-oxygen tetrahedra in the silicate network structure, causing the silicate network structure to depolymerize and generate negatively charged non-bridging oxygen (Si-O). - Simultaneously, calcium ions in calcium oxide, due to their high charge density, strongly attract the negative charge of non-bridging oxygen and interact strongly with it, further weakening the bridging bonds between adjacent silicon-oxygen tetrahedra in the silicate network structure. This promotes the breakage of more bridging oxygens, generating new non-bridging oxygens, thus producing a large amount of non-bridging oxygen. Non-bridging oxygen dipoles can react with water to generate hydroxyl groups, increasing the number of hydroxyl groups on the surface of the hydrophilic self-cleaning glaze.

[0057] In addition, the Ca contained in nano bovine bone ash 10 The phosphate ions in (PO4)6(OH)2 (hydroxycalcium hydroxyphosphate) can undergo limited hydrolysis with water to generate hydrolysis products such as hydrogen phosphate or dihydrogen phosphate. The hydroxyl groups in these hydrolysis products migrate to the surface of the hydrophilic self-cleaning glaze at high temperatures and are directionally enriched through chemical bonding or hydrogen bonding with surface defects, thereby significantly increasing the number of hydroxyl groups on the glaze surface.

[0058] Furthermore, the crystal unit cells of nano-anatase titanium dioxide are composed of [TiO6] octahedra, each Ti 4+ With 6 O 2- Coordination, the above O 2- This forms lattice oxygen (Ti-O-Ti bonds). Simultaneously, under ultraviolet light irradiation, the valence band electrons of nano-anatase titanium dioxide are excited to the conduction band, generating photogenerated electron-hole pairs (e-hole pairs). - -h + Holes (h+) preferentially oxidize the lattice oxygen of nano-anatase titanium dioxide, generating oxygen vacancies. Simultaneously, electrons (e+)... - )Reduced Ti 4+ For unstable Ti 3+ This forms surface defect sites. The aforementioned oxygen vacancies and Ti... 3+ The sites are highly active, preferentially adsorbing water molecules in the environment and dissociating to generate a hydroxyl coating layer, which also helps to increase the number of hydroxyl groups on the glaze surface.

[0059] Furthermore, the Ti exposed on the surface of nano-anatase phase titanium dioxide 4+ The site exhibits Lewis acidity, allowing it to adsorb water molecules from the environment, undergo heterolytic dissociation, and generate hydroxyl groups and protons (Ti). 4+ +H₂O→Ti 4+ -OH+H + Simultaneously, holes (h+) directly oxidize adsorbed water molecules, causing heterolytic dissociation to generate hydroxyl radicals (·OH) and protons (H+). + ), and the hydroxyl radical (·OH) reacts further with electrons, and then with Ti 4+ The combination forms Ti-OH, generating a hydroxyl group; the proton can react with neighboring lattice oxygen (Ti-O-Ti+H). + →Ti-OH+Ti+) reacts to form hydroxyl groups.

[0060] Furthermore, both micro / nano porous structures and micro / nano rough structures can improve the performance of Ti. 4+ Components that form hydroxyl groups, such as non-bridging oxygen, are more fully exposed on the glaze surface, thus providing a richer number of reactive sites. This increase in reactive sites allows Ti... 4+ Non-bridging oxygen and other compounds can react more fully with water to form more hydroxyl groups.

[0061] In summary, through the synergistic effect of the above-mentioned multiple aspects, the surface of the hydrophilic self-cleaning glaze is enriched with hydroxyl groups, which enhances the hydrogen bond adsorption capacity between the hydrophilic self-cleaning glaze and water molecules, improves the hydrophilicity of the surface of the hydrophilic self-cleaning glaze, and makes it easier for water to spread on the glaze surface and form a uniform water film, thereby carrying away and removing dirt from the surface of the antique bricks, thus improving the hydrophilic self-cleaning performance.

[0062] Furthermore, during the cooling process of the hydrophilic self-cleaning glaze layer, due to the tendency to minimize energy, positively charged calcium ions and negatively charged non-bridging oxygen atoms accumulate on the surface of the hydrophilic self-cleaning glaze layer and interact to generate calcium-non-bridging oxygen dipoles, thus enriching the surface of the hydrophilic self-cleaning glaze layer with calcium-non-bridging oxygen dipoles. Due to the strong polarization effect of calcium ions, these dipoles cause the local electron cloud to deflect towards oxygen atoms, resulting in local charge imbalance and the formation of strong dipole moments (such as Si-O). - …Ca 2+ This process creates a highly asymmetrical electron cloud distribution on the surface of the hydrophilic self-cleaning glaze, giving it high polarity. The high polarity of the glaze leads to hydrogen bonds or dipole-dipole interactions between the glaze and water molecules, reducing interfacial energy, making water spread more easily, enhancing the surface wettability of the glaze, and improving its self-cleaning properties.

[0063] Meanwhile, the nano-bovine bone ash in the formulation contains hydroxyapatite, and the phosphate ions in hydroxyapatite carry three negative charges, which can strongly attract hydrogen ions (H+) from water molecules. +They also form a hydrogen bond network through electrostatic interactions. Furthermore, the electrostatic interaction between polyvalent phosphate ions and water is stronger than that between ordinary hydroxyl groups and water, making water molecules spread more easily and significantly enhancing the surface wettability of the hydrophilic self-cleaning glaze, thereby improving the hydrophilic self-cleaning properties of the glaze.

[0064] In addition, the micron / nano-scale grooves in the micro-nano rough structure and the micro-nano porous structure generated during the calcination of calcite can generate capillary forces, which promote the spontaneous penetration of water molecules (i.e., capillary hydrophilic effect), further enhancing the wettability of water molecules on the surface of the hydrophilic self-cleaning glaze and improving the hydrophilic self-cleaning effect.

[0065] In summary, this technical solution, through the aforementioned multiple effects, endows the hydrophilic self-cleaning glaze layer with hydrophilic self-cleaning properties, making it easier to remove dirt even if it adheres to the surface. Furthermore, compared to hydrophilic self-cleaning coatings, the hydrophilic self-cleaning glaze layer exhibits significantly improved aging resistance, overcoming the technical deficiency of poor aging resistance in existing technologies that leads to poor long-term effectiveness of hydrophilic self-cleaning properties. Moreover, since the hydrophilic self-cleaning glaze layer is directly fired from the hydrophilic self-cleaning glaze material, its adhesion to antique-style bricks is extremely high, overcoming the technical deficiency of limited adhesion between existing hydrophilic self-cleaning coatings and antique-style brick surfaces, resulting in poor long-term effectiveness of hydrophilic self-cleaning properties. The synergy of these factors contributes to achieving long-lasting and excellent hydrophilic self-cleaning properties in antique-style bricks. In addition, this technical solution eliminates the need for additional hydrophilic self-cleaning coatings on the surface of antique-style bricks, saving production costs and improving production efficiency.

[0066] Finally, the nano-anatase phase titanium dioxide in this technical solution can also generate electron-hole pairs (e-hole pairs) under ultraviolet light excitation. - -h + Electron-hole pairs (e - -h + It can react with water vapor and / or oxygen in the air to generate substances such as hydroxyl radicals, superoxide radicals, and hydrogen peroxide. The reactive oxygen species in these substances can oxidize lipids, proteins, and nucleic acids in bacterial cells, leading to apoptosis. Simultaneously, nano-anatase titanium dioxide can continuously generate electron-hole pairs with antibacterial activity under photocatalysis, thus achieving a long-lasting antibacterial effect.

[0067] Furthermore, the nano zinc oxide in this technical solution can also achieve excellent and long-lasting antibacterial properties through the release of zinc ions and photocatalysis. The reasons are as follows: (1) Zinc ions are positively charged and easily bind to negatively charged phospholipids and proteins in the cell membrane of bacteria (such as bacteria or fungi), causing perforation of the cell membrane structure and leakage of contents such as potassium ions and adenosine triphosphate, thereby blocking the life activities of the bacteria and achieving a bactericidal effect; (2) Zinc ions bind to thiol groups and carboxyl groups in the bacteria, inhibiting the activity of key enzymes (such as dehydrogenases) and blocking energy metabolism; (3) Zinc ions are embedded in the DNA chain, interfering with the activity of RNA polymerase and DNA helicase, and preventing the proliferation of bacteria; (4) Zinc oxide is a wide bandgap semiconductor, which generates electron-hole pairs (e-hole pairs) under the excitation of ultraviolet or visible light. - -h + Electron-hole pairs (e - -h + (5) It can react with water vapor and / or oxygen in the air to generate hydroxyl radicals, superoxide radicals and hydrogen peroxide. The reactive oxygen free radicals in the above substances can oxidize lipids, proteins and nucleic acids in bacterial cells, leading to bacterial apoptosis; (6) Nano zinc oxide can pierce the cell wall of bacteria, especially the thick peptidoglycan layer of Gram-positive bacteria, leading to bacterial apoptosis; (7) The high specific surface area of ​​nano zinc oxide can adsorb a large number of bacteria, blocking their nutrient exchange and motility; (8) After killing bacteria, zinc ions can be released from the cells of bacteria and repeat the above antibacterial process, thus having a long-lasting antibacterial effect.

[0068] Furthermore, the micro-nano rough and micro-nano porous structures of the glaze surface are beneficial to improving antibacterial properties. The specific principles are as follows: (1) The micro-nano rough and micro-nano porous structures of the glaze surface significantly increase its specific surface area, allowing antibacterial components (such as titanium ions, zinc oxide, etc.) to be more fully exposed on the glaze surface, thereby providing more abundant reactive sites. The increase of the above-mentioned reactive sites allows antibacterial components to come into contact with bacteria more efficiently and trigger reactions, thereby accelerating the killing or growth inhibition process of bacteria. (2) The sharp edges of the micro-nano rough and micro-nano porous structures can directly pierce the cell wall or biofilm of bacteria when in contact with them, causing physical damage to the bacteria, thus providing additional protection for the antibacterial properties of the glaze surface; (3) The micro-nano rough and micro-nano porous structures of the glaze surface are also conducive to the effective diffusion of oxygen and moisture, promoting the reaction of antibacterial components with water vapor and / or oxygen in the air, generating more hydroxyl radicals, superoxide radicals, and hydrogen peroxide and other active substances with strong oxidizing properties. The increased amount of the aforementioned active substances further enhances the antibacterial properties of the glaze.

[0069] In summary, this technical solution, through multiple mechanisms, helps to endow antique-style bricks with high antibacterial properties.

[0070] Furthermore, this technical solution cannot use rutile phase titanium dioxide to replace anatase phase titanium dioxide because: (1) the photocatalytic activity is reduced; the band gap of rutile phase titanium dioxide is narrower, and the recombination rate of photogenerated electron-hole pairs is higher than that of anatase phase titanium dioxide, resulting in a decrease in the efficiency of surface redox reaction. This not only makes it difficult to continuously generate oxygen vacancies and hydroxyl capping layers, affecting the hydrophilic self-cleaning performance, but also reduces the recombination rate of electron-hole pairs (e - -h + (1) The amount of strong oxidizing substances such as hydroxyl radicals, superoxide radicals and hydrogen peroxide generated by the reaction with water vapor and / or oxygen in the air is reduced, which affects the antibacterial performance; (2) Poor surface hydroxyl stability: The structure of rutile phase titanium dioxide is more compact than that of anatase phase titanium dioxide, the coordination number of surface Ti atoms is higher (mainly 6 coordination), the oxygen vacancy formation energy is higher, and the adsorbed water molecules are easy to desorb, making it difficult to maintain a stable hydrophilic surface. (3) Thermodynamic stability and surface energy: Rutile phase is the thermodynamically stable phase of titanium dioxide, and its surface energy is usually lower than that of anatase phase. It tends to reduce surface defects (such as oxygen vacancies), thereby weakening the adsorption capacity for water molecules.

[0071] As can be seen from the above description, when rutile titanium dioxide transforms into anatase titanium dioxide, it will reduce the hydrophilic self-cleaning and antibacterial properties of the glaze. During the high-temperature calcination of hydrophilic glazes, anatase titanium dioxide is prone to undergo phase transformation into the more structurally stable rutile titanium dioxide. The nano zinc oxide added to the formulation system of this technical solution can inhibit the transformation of anatase titanium dioxide into rutile titanium dioxide, thereby preserving the activity of anatase titanium dioxide. The mechanism of nano zinc oxide inhibiting the transformation is as follows: (1) Zn 2+ The ionic radius (74 pm) of Ti 4+ (68pm) is close and can partially replace Ti in the anatase phase titanium dioxide lattice. 4+ To form a solid solution The above doping will cause the 3d orbitals of Zn to hybridize with the 3d orbitals of Ti, changing the band structure of titanium dioxide and making the anatase phase titanium dioxide more thermodynamically stable; (2) The phase transformation process of anatase phase titanium dioxide to rutile phase titanium dioxide requires grain growth to the critical size, while nano zinc oxide can be distributed at the grain boundaries of anatase phase titanium dioxide, hindering grain merging, thereby inhibiting the transformation of anatase phase titanium dioxide to rutile phase titanium dioxide; (3) Since oxygen vacancies are Ti 4+ To Ti 3+ The medium of transformation, and Ti 3+ It readily promotes the nucleation of rutile phase titanium dioxide, transforming anatase phase titanium dioxide into rutile phase titanium dioxide. Meanwhile, nano-zinc oxide itself acts as an oxygen adsorbent, consuming free oxygen in the environment and reducing oxygen vacancy migration in anatase phase titanium dioxide, thereby inhibiting Ti... 3+The formation of , thereby inhibiting the transformation of anatase titanium dioxide into rutile titanium dioxide.

[0072] It should be noted that, since the stability of nano-zinc oxide is limited at high temperatures, this technical solution utilizes hydroxyapatite from nano-bovine bone ash to enhance the stability of nano-zinc oxide, making its antibacterial effect more stable. The specific mechanism for enhancing stability is as follows: (1) The phosphate ions in hydroxyapatite have a high charge density, which can form stable zinc phosphate complexes (such as Zn3(PO4)2 or CaZn2(PO4)4) with zinc ions in zinc oxide, reducing the free state of zinc oxide and inhibiting its dissolution or aggregation; (2) The calcium ions in hydroxyapatite can partially replace zinc ions to form Ca-Zn-PO4 solid solution, stabilizing the crystal structure of zinc oxide and reducing the migration and loss of zinc ions; (3) During the high-temperature sintering process, hydroxyapatite can form a dense inorganic coating layer on the surface of zinc oxide particles, isolating water, oxygen and corrosive media (such as H2O) from the surface. + (4) Hydroxyphosphate can pin the grain boundaries of zinc oxide, preventing excessive growth of zinc oxide grains at high temperatures and maintaining its nano-effect and activity; (5) The introduction of hydroxyphosphate can reduce the photocatalytic self-corrosion of hydroxyphosphate in the glaze layer (such as the oxidation of itself by valence band holes of hydroxyphosphate under ultraviolet light).

[0073] Furthermore, if the amount of nano-bovine bone ash added to the formulation is too high, it will lead to an excessively high phosphate content, easily exceeding the critical value. This causes the formation of a phosphate network structure incompatible with the silicate matrix during high-temperature calcination, resulting in microphase separation of the glaze layer, reduced optical transmittance, non-uniform opacity, and impact on hydrophilic stability. Simultaneously, nano-bovine bone ash has high thermal stability; excessive addition will increase the refractoriness of the glaze, slow down the melting process, and lead to under-firing defects. Therefore, this technical solution limits the addition of nano-bovine bone ash to 2–6 parts to ensure the high-temperature fluidity of the glaze, avoid the formation of microphase separation structures, and obtain ideal surface hydrophilic properties. It should be noted that bovine bone ash exists as an inert filler in the glaze. When added in small amounts, its physical effects are mainly dispersion and interface regulation, without interfering with the glaze melting kinetics. Instead, it promotes densification by optimizing the microstructure; therefore, adding small amounts will not cause under-firing.

[0074] It should be further explained that the nano-bovine bone ash in this technical solution cannot be added to the hydrophilic frit. The reason is that the calcination temperature of the hydrophilic frit in the existing technology generally exceeds 1500℃. At this high temperature, the hydroxyl calcium phosphate in the nano-bovine bone ash will completely melt and decompose. This will not only significantly reduce the number of hydroxyl groups in the formula system, but also prevent the hydroxyl calcium phosphate from being used to increase the micro-nano rough structure of the glaze due to its complete melting. As a result, the hydrophilic self-cleaning glaze layer obtained by calcining the hydrophilic self-cleaning glaze will have reduced hydrophilic self-cleaning and antibacterial properties.

[0075] Furthermore, this technical solution requires the addition of some calcite to the hydrophilic frit in the formulation system. This is because the hydrophilic frit is a calcined material, while all other raw materials in the hydrophilic self-cleaning glaze, except for the hydrophilic frit, are raw materials. By introducing calcite into the calcined hydrophilic frit, the amount of calcite added to the raw material can be reduced. This avoids excessive carbon dioxide gas production during the calcination process of the hydrophilic self-cleaning glaze, which could lead to defects such as pinholes and excessively large pores on the glaze surface, thus ensuring the quality of the glaze surface.

[0076] To further clarify, in step B, the particle size of the nano-anatase phase titanium dioxide, the nano-zinc oxide, and the nano-bovine bone ash are all <20nm.

[0077] Nano-sized ox bone ash is rich in hydroxyapatite. When the particle size of nano-sized ox bone ash is limited to <20nm, the specific surface area of ​​nano-sized ox bone ash increases significantly, allowing more hydroxyl groups to be exposed on the surface of the hydrophilic self-cleaning glaze. This increases the number of hydroxyl groups on the surface of the hydrophilic self-cleaning glaze, thereby strengthening the hydrogen bond adsorption capacity between the hydrophilic self-cleaning glaze and water molecules, improving the hydrophilicity of the surface of the hydrophilic self-cleaning glaze, and making it easier for water to spread on the surface of the hydrophilic self-cleaning glaze and form a uniform water film, thereby carrying away and removing dirt from the surface of antique bricks, achieving the purpose of improving the hydrophilic self-cleaning effect.

[0078] Meanwhile, when the particle size of nano-bovine bone ash is limited to <20nm, the nano-bovine bone ash particles can be more evenly distributed in the glaze layer. During the calcination process, it is beneficial to form a more refined and uniform micro-nano rough structure, thereby further enhancing the hydrophilic self-cleaning effect.

[0079] Furthermore, by limiting the particle size of nano-zinc oxide to <20nm, nano-zinc oxide can better exert its role in restricting the conversion of anatase phase titanium dioxide to rutile phase titanium dioxide, thereby maintaining the activity of anatase phase titanium dioxide.

[0080] Furthermore, by limiting the particle size of nano-anatase titanium dioxide to <20nm, the nano-anatase titanium dioxide is more uniformly dispersed in the formulation system, which helps to ensure the performance of the obtained antique bricks.

[0081] To further clarify, in step B, the chemical composition of the nano-bovine bone ash, calculated by mass percentage, includes Ca. 10 (PO4)6(OH)2 60-75%, CaO 15-25%, MgO 5-8%, Na2O 3-5%, and K2O 1-2%.

[0082] This technical solution preferably uses Ca calculated as a mass percentage. 10Adding nano-bovine bone ash with a (PO4)6(OH)2 (hydroxyphosphate) content of 60-75% to the raw materials of hydrophilic self-cleaning glaze is beneficial to increasing the content of hydroxyphosphate in the formula system. This not only increases the number of hydroxyl groups on the surface of the hydrophilic self-cleaning glaze layer obtained by calcination, thereby improving the hydrophilic self-cleaning effect of the glaze layer, but also helps to ensure the high-temperature stability of nano-zinc oxide, making the antibacterial effect of nano-zinc oxide more stable.

[0083] Furthermore, this technical solution preferably incorporates nano-bovine bone ash with a calcium oxide content of 15-25% (by mass) into the raw materials of the hydrophilic self-cleaning glaze. This increases the calcium oxide content in the formulation system, which not only improves the surface tension of the hydrophilic self-cleaning glaze layer but also increases the amount of calcium feldspar generated in the formulation system, leading to the formation of more micro-nano rough structures, thereby enhancing hydrophilic self-cleaning performance and antibacterial properties. Simultaneously, it also promotes the formation of more non-bridging oxygen and calcium hydroxide in the system, increasing the number of hydroxyl groups on the glaze surface and thus improving hydrophilic self-cleaning performance. Furthermore, the increased calcium oxide content in the formulation system also facilitates the formation of more calcium-non-bridging oxygen dipoles, increasing the polarity of the glaze surface and further enhancing hydrophilic self-cleaning performance.

[0084] To further explain, in step B, the hydrophilic self-cleaning glaze, calculated by mass percentage, leaves a residue of 0.2-0.4% after passing through a 325-mesh sieve.

[0085] By limiting the fineness of the hydrophilic self-cleaning glaze, the raw materials in the hydrophilic self-cleaning glaze can be evenly dispersed, thereby ensuring the performance of the product.

[0086] To further explain, in step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.15 to 1.2.

[0087] When the specific gravity of the hydrophilic self-cleaning glaze is too high, the glaze becomes too thick, resulting in poor fluidity and uneven application, easily leading to defects such as glaze streaks. Furthermore, an excessively high specific gravity can also obstruct the escape of gases and moisture generated during firing, causing the glaze layer to crack easily. Conversely, if the specific gravity is too low, the glaze becomes too fluid, easily flowing during application, also resulting in uneven application and glaze streaks. Additionally, an excessively low specific gravity leads to excessive moisture in the glaze, potentially causing brick cracking during firing. Therefore, this technical solution limits the specific gravity of the hydrophilic self-cleaning glaze to 1.15–1.2, which helps ensure the uniformity of the hydrophilic self-cleaning effect and the quality of the glaze surface in the resulting antique-style bricks.

[0088] It should be noted that glaze streaks refer to areas where the glaze layer is thicker, while it is thinner or absent in other areas.

[0089] To further explain, in step B, the calcination temperature curve of the hydrophilic frit is as follows: the temperature is increased from room temperature to 1530°C at a heating rate of 8-10°C / min, and then held for 35-45 minutes.

[0090] By optimizing the calcination temperature curve of the hydrophilic frit, all raw materials in the hydrophilic frit formulation can be melted, which is beneficial to promote phase separation, ensure the performance of the hydrophilic frit, and make the hydrophilic self-cleaning glaze with added hydrophilic frit have a certain transparency after calcination, thus improving its permeability.

[0091] To further explain, in step B, the preparation steps for the hydrophilic self-cleaning glaze are as follows:

[0092] The raw materials for the hydrophilic frit are mixed evenly according to the formula, calcined, and then water-quenched to obtain the hydrophilic frit;

[0093] After mixing the raw materials of the hydrophilic self-cleaning glaze evenly according to the formula, sodium methyl cellulose, sodium hexametaphosphate and water are added and ball-milled, and then sieved to obtain the hydrophilic self-cleaning glaze; wherein, according to the mass percentage, the amount of water added is 33 to 50% of the dry material of the hydrophilic self-cleaning glaze.

[0094] This technical solution also proposes a method for preparing hydrophilic self-cleaning glaze. The preparation method is simple and easy to operate. By limiting the amount of water added to 33-50% of the dry material of the hydrophilic self-cleaning glaze, the water content in the hydrophilic self-cleaning glaze is relatively high, which is conducive to the uniform dispersion of nano-bovine bone ash in the hydrophilic self-cleaning glaze, thereby helping to ensure the performance of the hydrophilic self-cleaning glaze.

[0095] Preferably, the amount of sodium carboxymethyl cellulose added is 0.4 to 0.6% of the dry material of the hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.4 to 0.8% of the dry material of the hydrophilic self-cleaning glaze. After adding the above additives to the mixture, the mixture is ball-milled for 12 hours and then sieved to obtain the hydrophilic self-cleaning glaze.

[0096] Furthermore, this technical solution introduces sodium hexametaphosphate as a key additive. The six phosphate groups in the sodium hexametaphosphate molecule can preferentially react with polyvalent metal ions (such as Ca) in the formulation. 2+ It forms a highly stable chelate structure, which blocks ion bridging through steric hindrance, thereby inhibiting component aggregation and flocculation. At the same time, sodium hexametaphosphate, with its polyphosphate chain structure, exhibits stronger steric hindrance dispersion ability compared to sodium tripolyphosphate. It can uniformly disperse the raw materials in the glaze, avoid glaze defects caused by agglomeration, and ensure that the glaze maintains homogeneity and rheological stability during high-temperature calcination. Ultimately, it improves the density, hydrophilic self-cleaning performance, and antibacterial properties of the hydrophilic self-cleaning glaze layer.

[0097] To further explain, in step C, the thickness of the hydrophilic self-cleaning glaze is 0.05 to 0.1 mm.

[0098] If the thickness of the hydrophilic self-cleaning glaze is too thin, it will easily lead to glaze defects such as missed areas in the body, which will not only affect the uniformity of the hydrophilic self-cleaning property and antibacterial properties, but also affect the appearance of the product. If the thickness of the hydrophilic self-cleaning glaze is too thick, the high water content in the glaze will easily cause a sudden increase in internal steam pressure during rapid drying, which may break the bond strength between the body and the glaze, causing the body to crack or the glaze layer to peel off. In addition, the nano-bone ash particles are prone to micro-cracks due to stress concentration during drying shrinkage, further weakening the hydrophilic self-cleaning and antibacterial properties of the glaze layer. Therefore, this technical solution limits the thickness of the hydrophilic self-cleaning glaze to 0.05-0.1 mm, which is beneficial to ensuring the glaze quality, hydrophilic self-cleaning performance, and antibacterial performance of the hydrophilic self-cleaning antique bricks.

[0099] To further explain, in step D, the firing temperature curve of the hydrophilic self-cleaning antique brick includes a preheating section, a preheating section, a high-temperature section, a heat preservation section, a transition section, a rapid cooling section, a slow cooling section, a strong cooling section, and a final cooling section.

[0100] The preheating section takes 3 to 6 minutes to raise the temperature from room temperature to 750°C.

[0101] The temperature rises from 750°C to 1050°C in the initial temperature range, taking 1.2 to 4 minutes.

[0102] The high-temperature section rises from 1050℃ to 1145℃ in 5–8 minutes;

[0103] The insulation section is maintained at 1145℃ for 4.5–10 minutes.

[0104] The transition section cools the temperature from 1145℃ to 950℃ in 1.8–5 minutes.

[0105] The rapid cooling section reduces the temperature from 950°C to 630°C in 2–3 minutes.

[0106] The slow cooling section reduces the temperature from 630°C to 610°C in 5–10 minutes.

[0107] The rapid cooling section reduces the temperature from 610°C to 210°C in 3.5–6 minutes.

[0108] The final cooling section cools the temperature from 310°C to 200°C in 4–8 minutes.

[0109] This technical solution incorporates a rapid cooling section, which quickly freezes the high-temperature liquid phase structure, retaining more non-bridging oxygen and promoting the reaction between non-bridging oxygen and water molecules to generate more hydroxyl groups. Simultaneously, rapid cooling can inhibit the dehydration reaction of hydroxyl groups in calcium hydroxyphosphate, preventing hydroxyl group loss. This dual mechanism synergistically enhances the surface hydroxyl content.

[0110] Furthermore, the calcination cycle of this technical solution is 30–60 minutes, which belongs to the rapid firing mechanism. Rapid firing can suppress the excessive growth of crystals such as anorthite during the decomposition of calcite, preserving the micro-nano-scale porous structure produced by calcination. The rapid cooling section further solidifies this micro-nano-scale porous structure, making it uniformly distributed in the glaze layer. The aforementioned porous structure serves as a moisture adsorption site, promoting the hydrogen bonding between non-bridging oxygen and adsorbed water in the glaze layer and subsequent dissociation reactions, generating more surface hydroxyl groups to enhance the hydrophilic self-cleaning properties of the hydrophilic self-cleaning glaze layer.

[0111] A hydrophilic self-cleaning antique-style brick is prepared using the above-mentioned method. The static contact angle of the hydrophilic self-cleaning antique-style brick without soaking in boiling water is 2-7°, and the static contact angle after soaking in boiling water for 30 days is 9-15°. The antibacterial rate against Escherichia coli is ≥98.3%, the antibacterial rate against Staphylococcus aureus is ≥98.5%, the antibacterial durability against Escherichia coli is ≥88.1%, and the antibacterial durability against Staphylococcus aureus is ≥87.6%.

[0112] A hydrophilic self-cleaning antique brick prepared by the above-mentioned method has a static contact angle of 2-7° when not soaked in boiling water, and a static contact angle of 9-15° after soaking in boiling water for 30 days. It has an antibacterial rate of ≥98.3% against Escherichia coli, an antibacterial rate of ≥98.5% against Staphylococcus aureus, an antibacterial durability of ≥88.1% against Escherichia coli, and an antibacterial durability of ≥87.6% against Staphylococcus aureus. It not only has excellent and long-lasting hydrophilic self-cleaning properties, but also excellent and long-lasting antibacterial properties.

[0113] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0114] Performance testing:

[0115] Static contact angle before soaking: After irradiating the antique bricks with a 15W low-pressure ultraviolet lamp for 5 minutes, test the static contact angle of the antique bricks before soaking in boiling water according to the test method of "GB / T30447-2013 Nanofilm Contact Angle Measurement Method". If the static contact angle is ≤7°, it is qualified.

[0116] Static contact angle after soaking: After irradiating the antique bricks with a 15W low-pressure ultraviolet lamp for 5 minutes, test the static contact angle of the antique bricks after soaking in boiling water for 30 days according to the test method of "GB / T30447-2013 Nanofilm Contact Angle Measurement Method". If the static contact angle is ≤15°, it is qualified.

[0117] Antibacterial rate test: The antique bricks were sterilized at 120℃ and 0.11MPa for 20 minutes for later use. 10 4 CFU test bacterial suspension was inoculated onto the surface of sterilized antique bricks, covered with sterilized plastic wrap, placed in a 37°C incubator, and irradiated with a 15W low-pressure ultraviolet lamp. After 24 hours of incubation, the sample and the bacterial suspension in the plastic wrap were washed into petri dishes with physiological saline, diluted 10-fold, and then inoculated into petri dishes. The petri dishes were then placed in a 37°C incubator and incubated for 24 hours. The antibacterial rate was then calculated.

[0118] Antibacterial durability test: The surface of the antique bricks was washed 500 times with hypochlorous acid disinfectant, and then rinsed with sterile distilled water to obtain the washed antique bricks; the washed antique bricks were sterilized for 20 minutes at a temperature of 120℃ and a pressure of 0.11MPa to obtain sterilized antique bricks; 10 4 CFU test bacterial suspension was inoculated onto the surface of sterilized antique bricks, covered with sterilized plastic wrap, and placed in a 37°C incubator under irradiation with a 15W low-pressure ultraviolet lamp for 24 hours. Afterward, the sample and the bacterial suspension from the plastic wrap were washed onto petri dishes with physiological saline, diluted 10-fold, and then inoculated back into petri dishes. The dishes were then incubated at 37°C for another 24 hours, and the antibacterial rate was calculated. The hypochlorous acid disinfectant was a 5% hypochlorous acid solution by mass percentage.

[0119] Example 1

[0120] A. Prepare ceramic blanks, press the ceramic blanks, and dry them to obtain blanks with a textured surface.

[0121] B. Prepare hydrophilic self-cleaning glaze;

[0122] A mixture of 16 parts calcite, 18 parts wollastonite, 42 parts kaolin, 17 parts alumina, and 7 parts quartz was calcined and then water-quenched to obtain a hydrophilic frit. A mixture of 45 parts hydrophilic frit, 5 parts nano-anatase titanium dioxide, 25 parts quartz, 15 parts calcite, 6 parts nano-zinc oxide, and 4 parts nano-ox bone ash was then ball-milled with sodium methylcellulose, sodium hexametaphosphate, and water, and sieved to obtain a hydrophilic self-cleaning glaze. The nano-anatase titanium dioxide had a particle size of 10 nm; the nano-zinc oxide had a particle size of 8 nm; and the nano-ox bone ash had a particle size of 12 nm. The chemical composition of the nano-ox bone ash, calculated by mass percentage, included Ca... 10The composition is as follows: (PO4)6(OH)2 70%, CaO 17%, MgO 8%, Na2O 3%, and K2O 2%; Calculated by mass percentage, the amount of sodium carboxymethyl cellulose added is 0.5% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium hexametaphosphate added is 0.6% of the dry material of the hydrophilic self-cleaning glaze, and the amount of water added is 4% of the dry material of the hydrophilic self-cleaning glaze; Calculated by mass percentage, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, with a residue of 0.3%; The specific gravity of the hydrophilic self-cleaning glaze is 1.15; The calcination temperature curve of the hydrophilic frit is: heated from room temperature to 1530℃ at a heating rate of 10℃ / min, and then held for 40min;

[0123] C. Apply the hydrophilic self-cleaning glaze to the surface of the body to form a hydrophilic self-cleaning glaze layer; wherein the thickness of the hydrophilic self-cleaning glaze is 0.08mm.

[0124] D. After drying, the bricks are fired in a kiln to obtain hydrophilic self-cleaning antique-style bricks. The firing temperature curve of the hydrophilic self-cleaning antique-style bricks includes a preheating section, a preheating section, a high-temperature section, a heat preservation section, a transition section, a rapid cooling section, a slow cooling section, a strong cooling section, and a final cooling section. The preheating section raises the temperature from room temperature to 750℃ in 4 minutes; the preheating section raises the temperature from 750℃ to 1050℃ in 2 minutes; the high-temperature section raises the temperature from 1050℃ to 1145℃ in 5 minutes; the heat preservation section holds the temperature at 1145℃ for 5 minutes; the transition section lowers the temperature from 1145℃ to 950℃ in 3 minutes; the rapid cooling section lowers the temperature from 950℃ to 630℃ in 2 minutes; the slow cooling section lowers the temperature from 630℃ to 610℃ in 5 minutes; the strong cooling section lowers the temperature from 610℃ to 210℃ in 4 minutes; and the final cooling section lowers the temperature from 310℃ to 200℃ in 4 minutes.

[0125] Example 2

[0126] A. Prepare ceramic blanks, press the ceramic blanks, and dry them to obtain blanks with a textured surface.

[0127] B. Prepare hydrophilic self-cleaning glaze;

[0128] A mixture of 18 parts calcite, 15 parts wollastonite, 39 parts kaolin, 18 parts alumina, and 10 parts quartz was calcined and then water-quenched to obtain a hydrophilic frit. A mixture of 50 parts hydrophilic frit, 8 parts nano-anatase titanium dioxide, 18 parts quartz, 12 parts calcite, 6 parts nano-zinc oxide, and 6 parts nano-ox bone ash was then added, followed by ball milling and sieving to obtain a hydrophilic self-cleaning glaze. The nano-anatase titanium dioxide had a particle size of 12 nm; the nano-zinc oxide had a particle size of 10 nm; and the nano-ox bone ash had a particle size of 5 nm. The chemical composition of the nano-ox bone ash, calculated by mass percentage, included Ca... 10The composition is as follows: (PO4)6(OH)2 70%, CaO 17%, MgO 8%, Na2O 3%, and K2O 2%; Calculated by mass percentage, the amount of sodium carboxymethyl cellulose added is 0.4% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium hexametaphosphate added is 0.6% of the dry material of the hydrophilic self-cleaning glaze, and the amount of water added is 50% of the dry material of the hydrophilic self-cleaning glaze; Calculated by mass percentage, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, with a residue of 0.2%; The specific gravity of the hydrophilic self-cleaning glaze is 1.2; The calcination temperature curve of the hydrophilic frit is: heated from room temperature to 1530℃ at a heating rate of 8℃ / min, and then held for 45min;

[0129] C. Apply the hydrophilic self-cleaning glaze to the surface of the body to form a hydrophilic self-cleaning glaze layer; wherein the thickness of the hydrophilic self-cleaning glaze is 0.05mm.

[0130] D. After drying, the bricks are fired in a kiln to obtain hydrophilic self-cleaning antique-style bricks. The firing temperature curve of the hydrophilic self-cleaning antique-style bricks includes a preheating section, a preheating section, a high-temperature section, a heat preservation section, a transition section, a rapid cooling section, a slow cooling section, a strong cooling section, and a final cooling section. The preheating section raises the temperature from room temperature to 750℃ in 4 minutes; the preheating section raises the temperature from 750℃ to 1050℃ in 3 minutes; the high-temperature section raises the temperature from 1050℃ to 1145℃ in 6 minutes; the heat preservation section maintains the temperature at 1145℃ for 6 minutes; the transition section lowers the temperature from 1145℃ to 950℃ in 2 minutes; the rapid cooling section lowers the temperature from 950℃ to 630℃ in 3 minutes; the slow cooling section lowers the temperature from 630℃ to 610℃ in 10 minutes; the strong cooling section lowers the temperature from 610℃ to 210℃ in 4 minutes; and the final cooling section lowers the temperature from 310℃ to 200℃ in 6 minutes.

[0131] Example 3

[0132] A. Prepare ceramic blanks, press the ceramic blanks, and dry them to obtain blanks with a textured surface.

[0133] B. Prepare hydrophilic self-cleaning glaze;

[0134] A mixture of 19 parts calcite, 18 parts wollastonite, 40 parts kaolin, 15 parts alumina, and 8 parts quartz was calcined and then water-quenched to obtain a hydrophilic frit. A mixture of 42 parts hydrophilic frit, 3 parts nano-anatase titanium dioxide, 28 parts quartz, 18 parts calcite, 5 parts nano-zinc oxide, and 4 parts nano-ox bone ash was then ball-milled with sodium methylcellulose, sodium hexametaphosphate, and water, and sieved to obtain a hydrophilic self-cleaning glaze. The nano-anatase titanium dioxide had a particle size of 15 nm; the nano-zinc oxide had a particle size of 14 nm; and the nano-ox bone ash had a particle size of 10 nm. The chemical composition of the nano-ox bone ash, calculated by mass percentage, included Ca... 10The composition is as follows: (PO4)6(OH)2 70%, CaO 17%, MgO 8%, Na2O 3%, and K2O 2%; Calculated by mass percentage, the amount of sodium carboxymethyl cellulose added is 0.6% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium hexametaphosphate added is 0.4% of the dry material of the hydrophilic self-cleaning glaze, and the amount of water added is 35% of the dry material of the hydrophilic self-cleaning glaze; Calculated by mass percentage, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, with a residue of 0.4%; The specific gravity of the hydrophilic self-cleaning glaze is 1.18; The calcination temperature curve of the hydrophilic frit is: heated from room temperature to 1530℃ at a heating rate of 8℃ / min, and then held for 35–45 min;

[0135] C. Apply the hydrophilic self-cleaning glaze to the surface of the body to form a hydrophilic self-cleaning glaze layer; wherein the thickness of the hydrophilic self-cleaning glaze is 0.1 mm.

[0136] D. After drying, the bricks are fired in a kiln to obtain hydrophilic self-cleaning antique-style bricks. The firing temperature curve of the hydrophilic self-cleaning antique-style bricks includes a preheating section, a preheating section, a high-temperature section, a heat preservation section, a transition section, a rapid cooling section, a slow cooling section, a strong cooling section, and a final cooling section. The preheating section raises the temperature from room temperature to 750℃ in 5 minutes; the preheating section raises the temperature from 750℃ to 1050℃ in 4 minutes; the high-temperature section raises the temperature from 1050℃ to 1145℃ in 7 minutes; the heat preservation section holds the temperature at 1145℃ for 8 minutes; the transition section lowers the temperature from 1145℃ to 950℃ in 3 minutes; the rapid cooling section lowers the temperature from 950℃ to 630℃ in 2 minutes; the slow cooling section lowers the temperature from 630℃ to 610℃ in 7 minutes; the strong cooling section lowers the temperature from 610℃ to 210℃ in 6 minutes; and the final cooling section lowers the temperature from 310℃ to 200℃ in 7 minutes.

[0137] Comparative Example 1

[0138] The hydrophilic self-cleaning antique brick in Comparative Example 1 includes an antique brick substrate and a hydrophilic self-cleaning coating distributed from bottom to top; the hydrophilic self-cleaning coating is obtained by curing a super-hydrophilic coating of model SM-TM-QS3500 / 3200 from Shangmeng Technology Wuxi Co., Ltd.

[0139] Comparative Example 2

[0140] The preparation method and raw materials of Comparative Example 2 are the same as those of Example 1, except that the hydrophilic self-cleaning glaze of Comparative Example 2 does not contain nano-bovine bone ash.

[0141] Comparative Example 3

[0142] The preparation method and raw materials of Comparative Example 3 are the same as those of Example 1, except that calcite was not added to either the hydrophilic self-cleaning glaze or the hydrophilic frit of Comparative Example 3.

[0143] Comparative Example 4

[0144] Comparative Example 4 was prepared using the same method and raw materials as Example 1, except that nano zinc oxide was not added to the hydrophilic self-cleaning glaze of Comparative Example 4.

[0145] Comparative Example 5

[0146] Comparative Example 5 was prepared using the same method and raw materials as Example 1, except that nano-anatase titanium dioxide was not added to the hydrophilic self-cleaning glaze of Comparative Example 5.

[0147] The performance of the hydrophilic self-cleaning antique-style bricks prepared in the examples and comparative examples was tested, and the results are shown in Table 1 below:

[0148] Table 1. Performance test results of different hydrophilic self-cleaning antique bricks in the examples and comparative examples.

[0149]

[0150] As shown in Table 1, the static contact angle of the antique bricks obtained by this technical solution is 2-7° without being soaked in boiling water, and 9-15° after being soaked in boiling water for 30 days. The antibacterial rate against Escherichia coli is ≥98.3%, the antibacterial rate against Staphylococcus aureus is ≥98.5%, the antibacterial durability against Escherichia coli is ≥88.1%, and the antibacterial durability against Staphylococcus aureus is ≥87.6%. It not only has excellent and long-lasting hydrophilic self-cleaning properties, but also excellent and long-lasting antibacterial properties to meet actual use needs.

[0151] In Comparative Example 1, a hydrophilic self-cleaning coating was applied to the surface of the antique-style brick substrate to obtain a hydrophilic self-cleaning antique-style brick. Although the resulting antique-style brick had a small static contact angle with water before immersion and exhibited good hydrophilic self-cleaning properties, the poor aging resistance of the hydrophilic self-cleaning coating and its limited adhesion to the brick surface caused the coating to peel off after immersion. This resulted in poor hydrophilic self-cleaning durability, and the static contact angle after immersion could not be measured. Furthermore, the hydrophilic self-cleaning coating in Comparative Example 1 lacked antibacterial properties, rendering the resulting antique-style brick non-antibacterial.

[0152] In Comparative Example 2, the absence of nano-bovine bone ash not only prevented the utilization of the nano-bovine bone ash itself to enhance hydrophilic self-cleaning and antibacterial properties, but also prevented the utilization of the nano-bovine bone ash to enhance the high-temperature stability of nano-zinc oxide. This resulted in phenomena such as easy grain growth and self-corrosion of nano-zinc oxide during calcination, which affected its antibacterial properties and thus the antibacterial and hydrophilic self-cleaning properties of the antique bricks.

[0153] In Comparative Example 3, the absence of lightweight calcite reduced the amount of calcium oxide generated during glaze firing. This not only decreased the amount of anorthite generated, leading to a reduction in the micro-nano rough structure of the glaze surface, but also prevented the formation of micro-nano porous structures from the carbon dioxide gas produced by the decomposition of lightweight calcite, thus reducing the number of micro-nano porous structures and affecting hydrophilic self-cleaning and antibacterial properties. Simultaneously, the reduced calcium oxide generation weakened its enhancing effect on the surface tension of the glaze layer, impacting hydrophilic self-cleaning performance. Furthermore, it prevented the use of calcium oxide generated from the decomposition of lightweight calcite to increase the number of hydroxyl groups on the glaze surface through various pathways (such as hydrolysis and promoting the formation of non-bridging oxygen), also affecting hydrophilic self-cleaning performance. Additionally, it prevented the use of calcium oxide generated from the decomposition of lightweight calcite to increase the polarity of the glaze surface by forming calcium-non-bridging oxygen dipoles, further affecting hydrophilic self-cleaning performance.

[0154] In Comparative Example 4, the absence of nano-zinc oxide not only prevented the utilization of the hydrophilic self-cleaning and antibacterial properties of nano-zinc oxide, but also prevented the utilization of nano-zinc oxide to inhibit the conversion of anatase titanium dioxide to rutile titanium dioxide, thus affecting the hydrophilic self-cleaning and antibacterial properties.

[0155] In Comparative Example 5, no nano-anatase phase titanium dioxide was added, which prevented the utilization of the antibacterial and hydrophilic self-cleaning properties of nano-anatase phase titanium dioxide, resulting in a decrease in both antibacterial and hydrophilic self-cleaning properties.

[0156] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A method for preparing hydrophilic self-cleaning antique-style bricks, characterized in that, Includes the following steps: A. Prepare ceramic blanks, press the ceramic blanks, and dry them to obtain blanks with a textured surface. B. Prepare hydrophilic self-cleaning glaze; According to mass fractions, the raw materials of the hydrophilic self-cleaning glaze include 42-52 parts of hydrophilic frit, 3-9 parts of nano-anatase titanium dioxide, 18-30 parts of quartz, 10-18 parts of calcite, 3-7 parts of nano-zinc oxide, and 2-6 parts of nano-bovine bone ash, and the chemical composition of the nano-bovine bone ash includes Ca. 10 (PO4)6(OH)2 and CaO; According to the mass fractions, the raw materials of the hydrophilic frit include 15-19 parts of calcite, 15-19 parts of wollastonite, 32-52 parts of kaolin, 15-19 parts of alumina and 5-11 parts of quartz. C. Apply the hydrophilic self-cleaning glaze to the surface of the body to form a hydrophilic self-cleaning glaze layer; D. After drying, the bricks are fired in a kiln to obtain hydrophilic self-cleaning antique-style bricks.

2. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step B, the particle size of the nano-anatase phase titanium dioxide, the nano-zinc oxide, and the nano-bovine bone ash is all <20nm.

3. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step B, the chemical composition of the nano-bovine bone ash, calculated by mass percentage, includes Ca. 10 (PO4)6(OH)2 60-75%, CaO 15-25%, MgO 5-8%, Na2O 3-5%, and K2O 1-2%.

4. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step B, the hydrophilic self-cleaning glaze, calculated by mass percentage, leaves a residue of 0.2-0.4% after passing through a 325-mesh sieve.

5. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.15 to 1.

2.

6. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step B, the calcination temperature curve of the hydrophilic frit is as follows: the temperature is increased from room temperature to 1530°C at a heating rate of 8-10°C / min, and then held for 35-45 minutes.

7. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step B, the preparation steps for the hydrophilic self-cleaning glaze are as follows: The raw materials for the hydrophilic frit are mixed evenly according to the formula, calcined, and then water-quenched to obtain the hydrophilic frit; After mixing the raw materials of the hydrophilic self-cleaning glaze evenly according to the formula, sodium methyl cellulose, sodium hexametaphosphate and water are added and ball-milled, and then sieved to obtain the hydrophilic self-cleaning glaze; wherein, according to the mass percentage, the amount of water added is 33 to 50% of the dry material of the hydrophilic self-cleaning glaze.

8. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step C, the thickness of the hydrophilic self-cleaning glaze is 0.05 to 0.1 mm.

9. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 1, characterized in that, In step D, the firing temperature curve of the hydrophilic self-cleaning antique brick includes a preheating section, a preheating section, a high temperature section, a heat preservation section, a transition section, a rapid cooling section, a slow cooling section, a strong cooling section, and a final cooling section. The preheating section takes 3 to 6 minutes to raise the temperature from room temperature to 750°C. The temperature rises from 750°C to 1050°C in the initial temperature range, taking 1.2 to 4 minutes. The high-temperature section rises from 1050℃ to 1145℃ in 5–8 minutes; The insulation section is maintained at 1145℃ for 4.5–10 minutes. The transition section cools the temperature from 1145℃ to 950℃ in 1.8–5 minutes. The rapid cooling section reduces the temperature from 950°C to 630°C in 2–3 minutes. The slow cooling section reduces the temperature from 630°C to 610°C in 5–10 minutes. The rapid cooling section reduces the temperature from 610°C to 210°C in 3.5–6 minutes. The final cooling section cools the temperature from 310°C to 200°C in 4–8 minutes.

10. A hydrophilic self-cleaning antique-style brick, characterized in that: The hydrophilic self-cleaning antique brick is prepared using the preparation method of any one of claims 1 to 9. The static contact angle of the hydrophilic self-cleaning antique brick without soaking in boiling water is 2 to 7°, and the static contact angle after soaking in boiling water for 30 days is 9 to 15°. The antibacterial rate against Escherichia coli is ≥98.3%, the antibacterial rate against Staphylococcus aureus is ≥98.5%, the antibacterial durability against Escherichia coli is ≥88.1%, and the antibacterial durability against Staphylococcus aureus is ≥87.6%.

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