Antibacterial fabric based on nano-titanium dioxide and preparation method thereof

Abstract

The application belongs to the field of textile preparation, and particularly relates to a kind of antibacterial fabric based on nano titanium dioxide and a preparation method thereof.The antibacterial fabric based on nano titanium dioxide comprises a base cloth and a composite functional coating arranged on the surface of the base cloth;the composite functional coating is formed by applying a composite functional coating through a coating process and drying and curing;in terms of mass percentage, the components of the composite functional coating include 0.5-1 parts of nano titanium dioxide, 0-1 parts of an antibacterial synergist, 0.1-0.5 parts of a color paste, 5-10 parts of a binder, 0.5-1 parts of a thickening agent, 0.5-1 parts of a silane coupling agent, 0.1-0.5 parts of a surfactant and 86-93 parts of deionized water.The antibacterial fabric based on nano titanium dioxide provided by the application has excellent antibacterial properties under visible light without the need for ultraviolet light excitation, is washable and has good mechanical properties, is suitable for multiple scene applications, and the preparation process is environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of textile preparation, specifically relating to an antibacterial fabric based on nano-titanium dioxide and its preparation method. Background Technology

[0002] Traditional antibacterial textiles mostly use organic antibacterial agents, which suffer from low safety, easy development of drug resistance, and poor durability. Inorganic antibacterial materials, such as nano-titanium dioxide (TiO2), possess photocatalytic activity and can generate reactive oxygen species under visible light, efficiently decomposing bacteria and organic pollutants. They exhibit broad-spectrum antibacterial, UV-resistant, and self-cleaning functions, making them an important development direction for antibacterial textiles. However, the application of titanium dioxide in fabrics in existing technologies often faces problems such as agglomeration, uneven dispersion, and weak bonding with fibers, leading to rapid degradation of antibacterial performance and difficulty in meeting long-term use requirements. Furthermore, conventional TiO2 requires ultraviolet light excitation, while visible light accounts for over 90% of the ambient environment, resulting in low actual antibacterial efficiency. Summary of the Invention

[0003] Technical issues This invention aims to provide a titanium dioxide antibacterial fabric and its preparation method. By optimizing the formula and process, it solves the problems of poor dispersion and weak bonding of nano titanium dioxide in textiles, and achieves long-lasting antibacterial, anti-ultraviolet and self-cleaning functions of the fabric, while ensuring the environmental friendliness of the fabric preparation process and the durability of the fabric during use.

[0004] Technical solution The first aspect of this invention provides an antibacterial fabric based on nano-titanium dioxide, comprising: a base fabric and a composite functional coating disposed on the surface of the base fabric; the composite functional coating is formed by applying a composite functional coating through a coating process and then drying and curing; by mass percentage, the components of the composite functional coating include: 0.5-1 parts nano-titanium dioxide, 0-1 parts antibacterial synergist, 0.1-0.5 parts colorant, 5-10 parts adhesive, 0.5-1 parts thickener, 0.5-1 parts silane coupling agent, 0.1-0.5 parts surfactant, and 86-93 parts deionized water. The color paste in the composite functional coating of this invention imparts different colors to the fabric without affecting the antibacterial activity of titanium dioxide; the binder ensures that titanium dioxide adheres evenly to the fiber surface, enhances the bonding force between titanium dioxide and fiber, and reduces agglomeration; the thickener ensures stable viscosity and uniform coating of the slurry; the silane coupling agent enables a firm loading of the antibacterial agent on the titanium dioxide surface, slows down the loss of antibacterial components, and thus gives the material a long-lasting and stable antibacterial effect; the surfactant improves the wettability of the slurry, making the coating more uniform and avoiding local differences in antibacterial performance.

[0005] In some embodiments, the nano-titanium dioxide is visible light responsive TiO2 with anatase crystal form and a particle size of 7-30 nm; the antibacterial synergist is silver nitrate, nano-zinc oxide, or chitosan, and at least one of silver nitrate derivatives, nano-zinc oxide derivatives, or chitosan derivatives; the binder is an acrylate emulsion; the thickener is hydroxyethyl cellulose; the silane coupling agent is a 2.5%-3.5% KH-570 ethanol solution or a 0.5%-1.5% KH-570 deionized water solution; and the surfactant is sodium dodecyl sulfate or sodium dodecylbenzenesulfonate.

[0006] In some embodiments, the composite functional coating comprises 0.25-0.5 parts of antibacterial synergist, and the weight ratio of nano-titanium dioxide to antibacterial synergist is 1-2:1.

[0007] In some embodiments, the acrylate emulsion has a solid content of 50%, and the monomer composition of the acrylate is one or more of butyl acrylate, methyl methacrylate, or methacrylic acid. The acrylate emulsion further includes one or more of a comonomer, a crosslinking agent, an emulsifier, and an initiator, wherein the comonomer is styrene, the crosslinking agent is ethylene glycol dimethacrylate, and the initiator is persulfate.

[0008] In some embodiments, the acrylate emulsion comprises 30% butyl acrylate, 2% methyl methacrylate, 0.4% methacrylic acid, 13% styrene, 2% ethylene glycol dimethacrylate, 2% emulsifier, 0.6% persulfate, and 50% water.

[0009] In some embodiments, the silver nitrate derivative is silver nitrite; the nano zinc oxide derivative is a TiO2-ZnO nanocomposite; and the chitosan derivative is at least one of carboxymethyl chitosan and hydroxypropyl chitosan.

[0010] In some embodiments, the base fabric is pure cotton fabric, or a polyester-cotton blend fabric with a polyester-cotton ratio of 1.75-2:1. Pure cotton is a natural cellulose fiber with inherent core characteristics of high moisture absorption, high breathability, and skin-friendliness, making it suitable as a fabric for loungewear. A 1.75-2:1 polyester-cotton blend fabric combines the strength of polyester with the moisture absorption of cotton, and is also a common choice for medical and outdoor clothing fabrics.

[0011] In some embodiments, the amount of composite functional coating applied per square meter of the base fabric is 20 to 50 g.

[0012] In some embodiments, the antibacterial fabric based on nano-titanium dioxide exhibits an antibacterial rate of over 99% against Escherichia coli after 24 hours under visible light, and an antibacterial rate of over 90% against Escherichia coli after 24 hours under visible light after 10 standard washes.

[0013] In some embodiments, the antibacterial fabric based on nano-titanium dioxide retains approximately 95% of its tear strength and approximately 98% of its burst strength after 10 washes.

[0014] The second aspect of this invention provides a method for preparing the antibacterial fabric based on nano-titanium dioxide as described in any one of the above-mentioned methods, comprising the following steps: S1, alkaline washing treatment: washing a selected base fabric with an alkaline solution, then washing with water until neutral to obtain a clean base fabric; S2, silane coupling agent treatment: impregnating the clean base fabric from step S1 with a silane coupling agent, then drying to obtain a modified base fabric; S3, preparation of composite functional coating: mixing nano-titanium dioxide, antibacterial synergist, color paste, acrylic emulsion, thickener, silane coupling agent, surfactant, and deionized water according to a specified ratio to obtain a composite functional coating; S4, coating and curing treatment: coating the composite functional coating from step S3 onto the surface of the modified base fabric from step S2, and curing in stages to obtain a preliminary product; S5, post-treatment: cleaning and drying the preliminary product from step S4 to obtain the antibacterial fabric based on nano-titanium dioxide. Cleaning and chemical modification of natural fiber fabrics such as pure cotton can enhance their surface activity and strengthen their bonding with nanomaterials.

[0015] In some embodiments, the alkaline solution in step S1 is a 0.5% NaOH solution, and the alkaline washing treatment is performed at 60–80°C for 20–30 minutes. Alkaline washing can clean and modify the fabric, remove impurities from the surface of the base fabric fibers, slightly etch the fiber surface, and enhance its surface activity, thereby strengthening its adhesion to nanomaterials.

[0016] In some embodiments, the impregnation conditions in step S2 are room temperature for 25–35 minutes; the drying conditions are drying at 60°C for 30 minutes. The silane coupling agent treatment used in the impregnation enables a firm loading of the antibacterial agent on the titanium dioxide surface, slows down the loss of antibacterial components, and thus imparts a long-lasting and stable antibacterial effect to the material.

[0017] In some embodiments, the nano-titanium dioxide in step S3 is prepared by the following steps: thiourea and urea are dissolved in anhydrous ethanol, tetrabutyl titanate is added, the pH is adjusted to 3-4 with dilute nitric acid, and the mixture is stirred until homogeneous to obtain a mixed solution; deionized water is slowly added dropwise to the mixed solution, and after stirring until homogeneous, the mixture is allowed to stand to obtain a wet gel; the wet gel is dried at 50-80°C to obtain a dry gel; the dry gel is ground and refined to obtain sulfur and nitrogen co-doped nano-titanium dioxide powder.

[0018] In some embodiments, the mass ratio of thiourea, urea and tetrabutyl titanate ranges from 1:1:20-30.

[0019] In some embodiments, the specific conditions for the segmented curing process in step S4 are as follows: hot air drying at 110–130°C for 1.5–3 min, followed by hot pressing at 140–160°C for 0.5–2 min, and finally hot air drying at 90–110°C for 2–4 min followed by natural cooling to room temperature. Hot air drying can quickly evaporate moisture, ensuring the initial cross-linking of the acrylate emulsion and preventing titanium dioxide agglomeration caused by high temperature; high-temperature hot pressing can ensure complete curing of the adhesive, enhance fiber bonding, promote the chemical bonding of the silane coupling agent to the fiber surface, and improve antibacterial durability; gradual cooling can reduce internal stress, prevent thermal stress from causing coating cracking, and maintain the integrity of the antibacterial layer.

[0020] In some embodiments, the cleaning operation in step S5 specifically involves washing 2 to 4 times with laundry detergent or fiber softener; the drying operation specifically involves tumble drying at 50 to 70°C or at room temperature. Multiple washes are to remove excess pigment / residual reactants. After drying, avoid high temperatures and prolonged exposure to sunlight to prevent affecting the fabric's antibacterial effect.

[0021] Technical effect 1. The titanium dioxide antibacterial fabric prepared by this invention has excellent antibacterial properties under visible light, with a kill rate of over 99% against Escherichia coli in 24 hours; it also has good washability, with an antibacterial rate of about 90% after 10 standard washes, and the antibacterial function is long-lasting and stable. At the same time, the mechanical properties are low after washing, and the tear and burst strength retention rates after 10 washes are both higher than 95%, meeting the usage requirements.

[0022] 2. The base fabric of the material is modified by alkaline washing and silane coupling agent, which significantly improves the bonding strength between the fiber and the functional coating, making the nano-TiO2 evenly dispersed and firmly bonded to the fiber, effectively solving the industry pain points of agglomeration and easy detachment. At the same time, the nano-TiO2 in the fabric does not require ultraviolet light excitation and can achieve highly efficient antibacterial properties under visible light, making it suitable for daily use environments.

[0023] 3. The titanium dioxide antibacterial fabric prepared by this invention has antibacterial, anti-ultraviolet and self-cleaning functions. The preparation process is mild and environmentally friendly, with no harmful pollutant emissions. The finished fabric is skin-friendly and environmentally friendly, and can be adapted to multiple application scenarios such as medical, outdoor and home use.

[0024] 4. The antibacterial synergist works synergistically with nano-TiO2 to further enhance the antibacterial efficiency and washability of the fabric. Attached Figure Description

[0025] Figure 1 The visible light absorption spectrum of nano-titanium dioxide. Detailed Implementation

[0026] To facilitate the implementation of the technical solutions applied for, the terms and expressions involved in this invention will first be explained and defined in general terms and expressions below.

[0027] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0028] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0029] The room temperature mentioned in this invention specifically refers to 18-26℃.

[0030] The following is a further description of an antibacterial fabric based on nano-titanium dioxide and its preparation method provided by the present invention.

[0031] Example 1: Preparation of Nano-Titanium Dioxide Weigh out the components by weight, dissolve 1 part thiourea and 1 part urea in 12.5 parts anhydrous ethanol, then add 25 parts tetrabutyl titanate, adjust the pH to 3-4 with dilute nitric acid, and stir until homogeneous. Slowly add deionized water, continue stirring for 20 min, and let stand for 60 min to obtain a wet gel. Dry the wet gel at 60℃ to obtain a dry gel. Grind the dry gel into a fine powder to obtain sulfur-nitrogen co-doped titanium dioxide powder.

[0032] Example 2: Preparation of antibacterial fabric based on nano-titanium dioxide This embodiment specifically includes the following steps: Step 1, Base fabric selection: Use a polyester and cotton blend fabric (polyester / cotton ratio 65 / 35).

[0033] Step 2, Alkali washing treatment: Wash the base fabric with 0.5% NaOH solution at 60℃ for 20 min, then wash with water until neutral to obtain a clean base fabric.

[0034] Step 3, Silane Coupling Agent Treatment: The clean base fabric above was impregnated at room temperature for 30 min with a 3% γ-methacryloxypropyltrimethoxysilane (KH-570) ethanol solution and dried at 60℃ for 30 min to obtain the modified base fabric.

[0035] Step 4: Prepare the composite functional coating: Add the following components in sequence: 0.5% nano-titanium dioxide (prepared in Example 1, anatase crystal form, N and S doped), 0.2% blue pigment, 5% acrylate emulsion (manufacturer: Linxing Chemical; batch number: GH1537; solid content 50%: 30% butyl acrylate, 2% methyl methacrylate, 0.4% methacrylic acid, 13% styrene, 2% ethylene glycol dimethacrylate, 2% emulsifier, 0.6% persulfate), 0.5% hydroxyethyl cellulose, 0.5% silane coupling agent (3% KH-570 ethanol solution), 0.3% surfactant (sodium dodecyl sulfate, SDS), and 93% deionized water. The pH of the prepared composite functional coating is approximately 7.9.

[0036] Step 5, Coating and Curing Treatment: Apply the above-mentioned composite functional coating to the surface of the modified base fabric (the amount of composite functional coating applied per square meter of modified base fabric is 20 g), and obtain the initial product through segmented curing treatment; the segmented curing conditions are: hot air drying at about 120℃ for about 2 min, hot pressing at about 150℃ for about 1 min, treatment at about 100℃ for about 3 min, and then naturally cooling to room temperature.

[0037] Step 6, Post-treatment: Dry at 60℃ to obtain antibacterial fabric based on nano-titanium dioxide.

[0038] Example 3: Preparation of antibacterial fabric based on nano-titanium dioxide This embodiment specifically includes the following steps: Step 1, Base fabric selection: Use a polyester and cotton blend fabric (polyester / cotton ratio 65 / 35).

[0039] Step 2, Alkali washing treatment: Wash the base fabric with 0.5% NaOH solution at 60℃ for 20 min, then wash with water until neutral to obtain a clean base fabric.

[0040] Step 3, Silane Coupling Agent Treatment: The clean base fabric above was impregnated at room temperature for 30 min with a 3% γ-methacryloxypropyltrimethoxysilane (KH-570) ethanol solution and then dried to obtain the modified base fabric.

[0041] Step 4: Prepare the composite functional coating: Add the following in sequence: 1% nano-titanium dioxide (prepared in Example 1, anatase crystal form, N and S doped), 0.2% blue pigment, 5% acrylate emulsion (manufacturer: Linxing Chemical; batch number: GH1537; solid content 50%: 30% butyl acrylate, 2% methyl methacrylate, 0.4% methacrylic acid, 13% styrene, 2% ethylene glycol dimethacrylate, 2% emulsifier, 0.6% persulfate), 0.5% hydroxyethyl cellulose, 0.5% silane coupling agent (3% KH-570 ethanol solution), 0.3% surfactant (sodium dodecyl sulfate, SDS), and 92.5% deionized water.

[0042] Step 5, Coating and Curing Treatment: Apply the above-mentioned composite functional coating to the surface of the modified base fabric (the amount of composite functional coating applied per square meter of modified base fabric is 20 g), and obtain the initial product through segmented curing treatment; the segmented curing conditions are: hot air drying at about 120℃ for about 2 min, hot pressing at about 150℃ for about 1 min, treatment at about 100℃ for about 3 min, and then naturally cooling to room temperature.

[0043] Step 6, Post-treatment: Dry at 60℃ to obtain antibacterial fabric based on nano-titanium dioxide.

[0044] Example 4: Preparation of antibacterial fabric based on nano-titanium dioxide This embodiment specifically includes the following steps: Step 1, Base fabric selection: Use a polyester and cotton blend fabric (polyester / cotton ratio 65 / 35).

[0045] Step 2, Alkali washing treatment: Wash the base fabric with 0.5% NaOH solution at 60℃ for 20 min, then wash with water until neutral to obtain a clean base fabric.

[0046] Step 3, Silane Coupling Agent Treatment: The clean base fabric above was impregnated at room temperature for 30 min with a 3% γ-methacryloxypropyltrimethoxysilane (KH-570) ethanol solution and then dried to obtain the modified base fabric.

[0047] Step 4: Prepare the composite functional coating: Add the following in sequence: 1% nano-titanium dioxide (prepared in Example 1, anatase crystal form, N and S doped), 0.2% blue pigment, 5% acrylate emulsion (manufacturer: Linxing Chemical; batch number: GH1537; solid content 50%: 30% butyl acrylate, 2% methyl methacrylate, 0.4% methacrylic acid, 13% styrene, 2% ethylene glycol dimethacrylate, 2% emulsifier, 0.6% persulfate), 1% hydroxyethyl cellulose, 0.5% silane coupling agent (3% KH-570 ethanol solution), 0.3% surfactant (sodium dodecyl sulfate, SDS), and 92% deionized water.

[0048] Step 5, Coating and Curing Treatment: Apply the above-mentioned composite functional coating to the surface of the modified base fabric (the amount of composite functional coating applied per square meter of modified base fabric is 20 g), and obtain the initial product through segmented curing treatment; the segmented curing conditions are: hot air drying at about 120℃ for about 2 min, hot pressing at about 150℃ for about 1 min, treatment at about 100℃ for about 3 min, and then naturally cooling to room temperature.

[0049] Step 6, Post-processing: Dry at 60℃ to obtain antibacterial fabric based on nano-titanium dioxide.

[0050] Example 5: Preparation of antibacterial fabric based on nano-titanium dioxide Step 1, Base fabric selection: Use a polyester and cotton blend fabric (polyester / cotton ratio 65 / 35).

[0051] Step 2, Alkali washing treatment: Wash the base fabric with 0.5% NaOH solution at 60℃ for 20 min, then wash with water until neutral to obtain a clean base fabric.

[0052] Step 3, Silane Coupling Agent Treatment: The clean base fabric above was impregnated at room temperature for 30 min with a 3% γ-methacryloxypropyltrimethoxysilane (KH-570) ethanol solution and then dried to obtain the modified base fabric.

[0053] Step 4: Prepare the composite functional coating: Add the following in sequence: 1% nano-titanium dioxide (prepared in Example 1, anatase crystal form, N and S doped), 1% nano-zinc oxide, 0.2% color paste, 5% acrylic emulsion (manufacturer: Linxing Chemical; batch number: GH1537; solid content 50%: 30% butyl acrylate, 2% methyl methacrylate, 0.4% methacrylic acid, 13% styrene, 2% ethylene glycol dimethacrylate, 2% emulsifier, 0.6% persulfate), 1% hydroxyethyl cellulose, 0.5% silane coupling agent (3% KH-570 ethanol solution), 0.3% surfactant (sodium dodecyl sulfate, SDS), and 91% deionized water.

[0054] Step 5, Coating and Curing Treatment: Apply the above-mentioned composite functional coating to the surface of the modified base fabric (the amount of composite functional coating applied per square meter of modified base fabric is 20 g), and obtain the initial product through segmented curing treatment; the segmented curing conditions are: hot air drying at about 120℃ for about 2 min, hot pressing at about 150℃ for about 1 min, treatment at about 100℃ for about 3 min, and then naturally cooling to room temperature.

[0055] Step 6: Post-treatment, drying at 60℃ to obtain antibacterial fabric based on nano-titanium dioxide.

[0056] Comparative Example 1: Configuration of fabrics without antibacterial function Step 1, Base fabric selection: Use a polyester and cotton blend fabric (polyester / cotton ratio 65 / 35).

[0057] Step 2, Alkali washing treatment: Wash the base fabric with 0.5% NaOH solution at 80℃ for 30 min, then wash with water until neutral to obtain a clean base fabric.

[0058] Step 3, Silane Coupling Agent Treatment: The clean base fabric above was impregnated at room temperature for 30 min with a 3% γ-methacryloxypropyltrimethoxysilane (KH-570) ethanol solution and then dried to obtain the modified base fabric.

[0059] Step 4: Prepare a coating without antibacterial function: 0.2% color paste, 5% acrylic emulsion, 1% hydroxyethyl cellulose, 0.5% silane coupling agent (3% KH-570 ethanol solution), 0.3% surfactant (sodium dodecyl sulfate, SDS), and 93% deionized water.

[0060] Step 5, Coating and Curing Treatment: Apply the above-mentioned non-antibacterial coating to the surface of the modified base fabric (the amount of non-antibacterial coating per square meter of modified base fabric is 20 g), and obtain the initial product through segmented curing treatment; the segmented curing conditions are: hot air drying at about 120℃ for about 2 min, hot pressing at about 150℃ for about 1 min, treatment at about 100℃ for about 3 min, and then naturally cooling to room temperature.

[0061] Step 6, Post-treatment: Dry at 60℃.

[0062] Test Example 1: Determination of Antibacterial Properties The antibacterial performance was determined according to the testing standard of T / CIAA 103.1-2021 "Antibacterial Technical Specification Part 1: Antibacterial Products".

[0063] Table 1. Antibacterial rate of antimicrobial fabrics (taking Escherichia coli as an example)

[0064] As shown in Table 1, under 500 lux of visible light, the fabric prepared by this invention has a kill rate of about 99% against Escherichia coli after 24 h, while the comparative example without the addition of nano titanium dioxide has a kill rate of about 0% against Escherichia coli after 24 h.

[0065] Test Example 2: Wash Resistance Test Table 2. Antibacterial properties of antibacterial fabrics after ten washes (using Escherichia coli as an example)

[0066] As shown in Table 2, the antibacterial rate of the fabric prepared by the present invention is about 90% after 10 washes and 24 hours, while the comparative sample is still 0%.

[0067] Test Example 3 Mechanical Property Determination The breaking strength and elongation at break were determined according to GB / T 3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break". The fabric was required to retain approximately 80% of its tear strength and approximately 80% of its bursting strength after 10 washes.

[0068] Table 3 Mechanical properties of antibacterial fabrics

[0069] As shown in Table 3, the fabric prepared by the present invention has a tear strength retention rate of over 95% and a bursting strength retention rate of approximately 98% after 10 washes, which meets the requirements.

[0070] Experimental Example 4: Visible Light Response Test like Figure 1 As shown, the nano-titanium dioxide (prepared in Example 1) used in the fabric preparation of this invention has a characteristic absorption peak at 500 nm, proving that the nano-titanium dioxide is visible light responsive. Subsequent testing revealed that the fabric prepared using this nano-titanium dioxide still possesses antibacterial properties without ultraviolet light excitation, which is sufficient to prove that it is visible light responsive.

[0071] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. An antibacterial fabric based on nano-titanium dioxide, characterized in that, include: The base fabric and the composite functional coating applied to the surface of the base fabric; The composite functional coating is formed by applying composite functional paint through a coating process and then drying and curing it. The composite functional coating comprises, by mass percentage: 0.5-1 parts nano-titanium dioxide, 0-1 parts antibacterial synergist, 0.1-0.5 parts color paste, 5-10 parts binder, 0.5-1 parts thickener, 0.5-1 parts silane coupling agent, 0.1-0.5 parts surfactant, and 86-93 parts deionized water.

2. The antibacterial fabric based on nano-titanium dioxide according to claim 1, characterized in that, The nano-titanium dioxide is visible light responsive TiO2 with anatase crystal form and a particle size of 7-30 nm; the antibacterial synergist is silver nitrate, nano-zinc oxide, or chitosan, and at least one of silver nitrate derivatives, nano-zinc oxide derivatives, or chitosan derivatives; the adhesive is an acrylic emulsion; the thickener is hydroxyethyl cellulose or a polyurethane thickener; the silane coupling agent is a 2.5%-3.5% KH-570 ethanol solution or a 0.5%-1.5% KH-570 deionized water solution; the surfactant is sodium dodecyl sulfate or sodium dodecylbenzenesulfonate.

3. The antibacterial fabric based on nano-titanium dioxide according to claim 1, characterized in that, The base fabric is pure cotton fabric, or a polyester-cotton blend fabric with a polyester-cotton ratio of 1.75-2:

1.

4. The antibacterial fabric based on nano-titanium dioxide according to claim 1, characterized in that, The coating amount of the composite functional coating on the base fabric is 20-50 g per square meter.

5. The method for preparing the antibacterial fabric based on nano-titanium dioxide according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Alkaline washing treatment: The selected base fabric is washed with an alkaline solution and then washed with water until neutral to obtain a clean base fabric. S2, Silane Coupling Agent Treatment: The clean base fabric from step S1 is impregnated with a silane coupling agent and then dried to obtain the modified base fabric. S3. Preparation of composite functional coating: Nano titanium dioxide, antibacterial synergist, color paste, acrylic emulsion, thickener, silane coupling agent, surfactant and deionized water are mixed according to the formula to obtain composite functional coating. S4. Coating and curing treatment: The composite functional coating from step S3 is coated onto the surface of the modified base fabric from step S2, and the initial product is obtained through segmented curing treatment. S5. Post-processing: The initial product from step S4 is cleaned and dried to obtain the antibacterial fabric based on nano-titanium dioxide.

6. The preparation method according to claim 5, characterized in that, The alkaline solution mentioned in step S1 is a 0.5% NaOH solution, and the alkaline washing treatment conditions are 60-80℃ for 20-30 min.

7. The preparation method according to claim 5, characterized in that, The immersion conditions in step S2 are room temperature for 25–35 minutes; the drying conditions are hot air drying at 60°C for 25–35 minutes.

8. The preparation method according to claim 5, characterized in that, The nano-titanium dioxide described in step S3 is prepared through the following steps: Thiourea and urea were dissolved in anhydrous ethanol, tetrabutyl titanate was added, the pH was adjusted to 3-4 with dilute nitric acid, and the mixture was stirred until homogeneous to obtain a mixed solution. Deionized water was slowly added dropwise to the mixed solution, and after stirring until homogeneous, the mixture was allowed to stand to obtain a wet gel. The wet gel was dried at 50–80°C to obtain a dry gel. The dry gel is ground and refined to obtain sulfur and nitrogen co-doped nano-titanium dioxide powder.

9. The preparation method according to claim 5, characterized in that, The specific conditions for the segmented curing process in step S4 are as follows: hot air drying at 110–130°C for 1.5–3 min, followed by hot pressing at 140–160°C for 0.5–2 min, and finally hot air drying at 90–110°C for 2–4 min followed by natural cooling to room temperature.

10. The preparation method according to claim 5, characterized in that, The specific cleaning operation in step S5 is as follows: wash 2 to 4 times with laundry detergent or fabric softener; the specific drying operation is as follows: dry at 50 to 70°C or dry at room temperature.

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