Silver-doped carbon quantum dots-based antibacterial cotton fiber, and preparation method and application thereof
By synthesizing silver-doped carbon quantum dots using a microwave method and then chemically modifying cotton fibers, the problem of weak bonding force was solved, and efficient and stable antibacterial cotton fiber preparation was achieved, which is suitable for a variety of textiles and filter materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI ACAD OF AGRI SCI ECONOMIC CROPS RES INST
- Filing Date
- 2026-04-20
- Publication Date
- 2026-06-09
AI Technical Summary
Existing carbon quantum dots have weak adhesion and poor fastness to cotton fibers, making them easy to fall off, resulting in insufficient antibacterial efficiency and uneven effects. Existing preparation methods are cumbersome and difficult to achieve long-term stable antibacterial effects.
Silver-doped carbon quantum dots were synthesized using a microwave method. Through chemical modification of cotton fibers, a covalent/coordination composite structure of silver-doped carbon quantum dots was formed. Ag-CQDs were firmly loaded onto the surface of cotton fibers using covalent bonds, coordination bonds, and hydrogen bonds to form a uniform, continuous, and robust antibacterial coating.
A highly efficient combination of silver-doped carbon quantum dots and cotton fibers was achieved, resulting in a long-lasting antibacterial fiber with low toxicity, high stability, and good bonding strength, suitable for medical, daily textiles, and filter materials.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of functional textile materials technology, and in particular to an antibacterial cotton fiber based on silver-doped carbon quantum dots, its preparation method, and its application. Background Technology
[0002] With the improvement of living standards and the enhancement of health awareness, people are paying increasing attention to the impact of bacteria and other microorganisms on their health. The rational selection of antibacterial textile products is crucial for reducing bacterial infections and safeguarding human health. Cotton fiber, as one of the most widely used natural fibers, occupies an important position in the textile industry due to its excellent moisture absorption, breathability, and wearing comfort, and is widely used in clothing, home textiles, and medical supplies. However, cotton fiber itself does not possess antibacterial properties. Its main component is cellulose, which is rich in hydrophilic groups such as hydroxyl groups. In humid environments, it easily absorbs moisture, providing an ideal environment for microbial growth. Once microorganisms multiply rapidly on cotton fiber products, it can not only cause odors, discoloration, and decreased strength in the fabric, shortening its lifespan, but more seriously, it may trigger health problems such as skin allergies and infections, posing a greater threat, especially to people with weakened immune systems. With the improvement of people's living standards, the demand for antibacterial modification or finishing of cotton fiber products is also increasing.
[0003] Carbon quantum dots, as a novel zero-dimensional carbon nanomaterial, possess advantages such as abundant raw materials, high biocompatibility, low toxicity, easily tunable surface functional groups, and unique optoelectronic properties. Recent studies have shown that by rationally designing precursors and synthetic pathways, carbon quantum dots with excellent antibacterial activity can be obtained. Their antibacterial mechanisms mainly include physical puncture and disruption of bacterial cell membranes, generation of reactive oxygen species for oxidative killing, and interference with bacterial metabolism through electrostatic adsorption. Compared with conventional antibacterial agents, carbon quantum dots are less likely to induce drug resistance in microorganisms, resulting in higher safety.
[0004] However, while carbon quantum dots possess excellent antibacterial potential, their application to cotton fibers generally suffers from weak bonding and poor fastness, easily detaching after washing or rubbing, making it difficult to achieve long-lasting and stable antibacterial effects. Furthermore, the low loading and poor dispersibility of carbon quantum dots on cotton fiber surfaces lead to agglomeration, resulting in insufficient and uneven antibacterial efficiency. In addition, existing preparation methods often involve multi-step modification and complex processes, limiting their practical application and industrialization in the textile industry. Summary of the Invention
[0005] The purpose of this invention is to provide an antibacterial cotton fiber based on silver-doped carbon quantum dots, its preparation method and application. Silver and carbon quantum dots are loaded onto the surface of cotton fibers as efficient and safe antibacterial agents, which can improve the antibacterial effect of cotton fibers and achieve long-term antibacterial properties. Moreover, the preparation method is simple and easy to implement.
[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing antibacterial cotton fibers based on silver-doped carbon quantum dots, comprising the following steps: The silver salt solution and carbon source solution were mixed and subjected to microwave heat treatment, followed by separation and dialysis to obtain a silver-doped carbon quantum dot dispersion. Cotton fibers are mixed with an aqueous solution of a surfactant for pretreatment to obtain pretreated cotton fibers. The pretreated cotton fibers, benzenesulfonyl chloride, triethylamine and organic solvent are mixed and activated to obtain activated cotton fibers; The activated cotton fibers were impregnated in a silver-doped carbon quantum dot dispersion and loaded to obtain antibacterial cotton fibers based on silver-doped carbon quantum dots.
[0007] Preferably, the silver salt in the silver salt solution includes silver nitrate; the carbon source in the carbon source solution includes tryptophan or citric acid; the concentration of the silver salt solution is 0.1~0.2 mol / L; and the concentration of the carbon source solution is 0.01~0.05 mol / L. The volume ratio of the silver salt solution to the carbon source solution is 0.5~5:10~100.
[0008] Preferably, the microwave heat treatment has a power of 500-800 W and a time of 20-40 min; the dialysis bag used for dialysis has a molecular weight cutoff of 500-1000 Da; and the dialysis time is 24-48 h.
[0009] Preferably, the surfactant in the aqueous surfactant solution includes Triton X-100; the concentration of the aqueous surfactant solution is 0.5~2g / L, and the volume ratio of the aqueous surfactant solution to the mass of the cotton fiber is 50~150mL:1g.
[0010] Preferably, the pretreatment temperature is 45~70°C and the time is 20~60 min.
[0011] Preferably, the mass ratio of the pretreated cotton fiber to benzenesulfonyl chloride is 1~2:0.05~0.1; the mass ratio of benzenesulfonyl chloride to triethylamine is 3~4:4~6; and the mass ratio of the pretreated cotton fiber to the organic solvent is 1~2:25~50.
[0012] Preferably, the activation treatment conditions include: pH=7, temperature 45~60℃, and reaction time in the dark 24~72h.
[0013] Preferably, the mass ratio of the activated cotton fiber to the silver-doped carbon quantum dots in the silver-doped carbon quantum dot dispersion is 1~3g:0.5~2mg; the loading temperature is room temperature, and the loading time is 36~72h; the loading is carried out under light-protected and static conditions.
[0014] This invention provides antibacterial cotton fibers based on silver-doped carbon quantum dots prepared by the preparation method described in the above technical solution.
[0015] The present invention provides the application of the antibacterial cotton fiber based on silver-doped carbon quantum dots described above in medical textiles, daily textiles or filter materials.
[0016] This invention provides a method for preparing antibacterial cotton fibers based on silver-doped carbon quantum dots (Ag-CQDs). The method employs a microwave method to rapidly synthesize silver-doped carbon quantum dots (Ag-CQDs). Utilizing the instantaneous high temperature, uniform heating, and electron transfer-promoting properties of microwaves, silver ions rapidly combine with the oxygen- and nitrogen-containing functional groups of the carbon precursor, forming a covalent / coordination composite structure of silver-doped carbon quantum dots. Further chemical modification of the cotton fibers generates numerous active reaction sites on the fiber surface. Finally, Ag-CQDs are firmly loaded onto the cotton fiber surface and surface voids through covalent bonds, coordination bonds, and hydrogen bonds, forming a uniform, continuous, robust, and washable antibacterial coating. The process of this invention is simple, green, environmentally friendly and efficient. Compared with single carbon quantum dots or silver-based antibacterial agents, the cotton fiber based on silver-doped carbon quantum dots has long-lasting antibacterial properties due to the synergistic bactericidal effect of multiple mechanisms (silver + carbon quantum dots). It also has low toxicity, high stability and good binding strength. It can be applied to medical textiles, daily textiles and filter materials, showing excellent application prospects in the field of long-lasting antibacterial textile materials. Detailed Implementation
[0017] In this invention, unless otherwise specified, the raw materials or reagents required for preparation are all commercially available products well known to those skilled in the art.
[0018] This invention provides a method for preparing antibacterial cotton fibers based on silver-doped carbon quantum dots, comprising the following steps: The silver salt solution and carbon source solution were mixed and subjected to microwave heat treatment, followed by separation and dialysis to obtain a silver-doped carbon quantum dot dispersion. Cotton fibers are mixed with an aqueous solution of a surfactant for pretreatment to obtain pretreated cotton fibers. The pretreated cotton fibers, benzenesulfonyl chloride, triethylamine and organic solvent are mixed and activated to obtain activated cotton fibers; The activated cotton fibers were impregnated in a silver-doped carbon quantum dot dispersion and loaded to obtain antibacterial cotton fibers based on silver-doped carbon quantum dots.
[0019] In this invention, the silver salt in the silver salt solution preferably includes silver nitrate; the concentration of the silver salt solution is preferably 0.1~0.2 mol / L, more preferably 0.1~0.15 mol / L; and the solvent used for the silver salt solution is preferably water.
[0020] In this invention, the carbon source in the carbon source solution preferably includes tryptophan or citric acid; the concentration of the carbon source solution is preferably 0.01~0.05 mol / L, more preferably 0.02~0.04 mol / L; and the solvent used for the carbon source solution is preferably distilled water.
[0021] In this invention, the volume ratio of the silver salt solution to the carbon source solution is preferably 0.5~5:10~100, more preferably 1~1.5:25~50, and even more preferably 1:25~40.
[0022] In this invention, the silver salt solution is mixed with the carbon source solution and then heat-treated in a microwave oven.
[0023] In this invention, the power of the microwave heat treatment is preferably 500~800 W, more preferably 600~700 W, and the time is preferably 20~40 min, more preferably 30 min.
[0024] After microwave heat treatment, the resulting mixture was cooled to room temperature, ultrapure water was added and centrifuged, and then filtered with a polytetrafluoroethylene syringe filter with a pore size of 0.22µm to remove large particles. The filtered solution was dialyzed with a dialysis bag to obtain a silver-doped carbon quantum dot dispersion in which silver exists in the form of nano-silver.
[0025] In this invention, the molecular weight cutoff of the dialysis bag used for dialysis is preferably 500-1000 Da, more preferably 600-800 Da, and the dialysis time is preferably 24-48 h, more preferably 36 h.
[0026] In this invention, the surfactant in the surfactant aqueous solution preferably includes Triton X-100; the concentration of the surfactant aqueous solution is preferably 0.5~2g / L, more preferably 1~1.5g / L, and the solvent used is preferably distilled water; the volume ratio of the surfactant aqueous solution to the mass of cotton fiber is preferably 50~150mL:1g, more preferably 60~100mL:1g.
[0027] In this invention, it is preferable to pretreat the cotton fibers by immersing them entirely in an aqueous solution of a surfactant.
[0028] In this invention, the pretreatment temperature is preferably 45~70°C, more preferably 55~60°C, and the pretreatment time is preferably 20~60 min, more preferably 30~50 min. This invention removes wax and hydrophobic impurities from the surface of cotton fibers through pretreatment, allowing the fibers to become fully hydrophilic and swollen, exposing more hydroxyl groups, thereby improving the uniformity and binding strength of the subsequent silver-doped carbon quantum dots loading.
[0029] After pretreatment, the obtained fibers are rinsed repeatedly with distilled water until residual detergent is removed, and then dried in an oven to obtain pretreated cotton fibers. The drying temperature is preferably 45~60℃, more preferably 50~55℃, and the drying time is preferably 6~8h, more preferably 7~8h.
[0030] In this invention, the mass ratio of the pretreated cotton fiber to benzenesulfonyl chloride is preferably 1~2:0.05~0.1, more preferably 1~1.5:0.05~0.08; the mass ratio of benzenesulfonyl chloride to triethylamine is preferably 3~4:4~6, more preferably 3~4:4~5.
[0031] In this invention, the organic solvent preferably includes acetonitrile; the mass ratio of the pretreated cotton fiber to the organic solvent is preferably 1~2:25~50, more preferably 1~2:30~50.
[0032] In this invention, pretreated cotton fibers are preferably immersed in an organic solvent, and benzenesulfonyl chloride (BSC) and triethylamine (TEA) are added. The mixture is stirred in the dark to activate the fibers. In this invention, benzenesulfonyl chloride acts as a sulfonation activator, converting the low-activity hydroxyl groups on the surface of the cotton fibers into highly active benzenesulfonate intermediates; triethylamine acts as an acid-binding agent and catalyst, promoting the deprotonation of hydroxyl groups and neutralizing the hydrogen chloride generated in the reaction.
[0033] In this invention, the activation treatment conditions preferably include: pH=7, temperature 45~60℃, more preferably 50~55℃, and reaction time in the dark 24~72h, more preferably 36~48h. This invention converts the main active group cellulose hydroxyl (-OH) on the surface of cotton fibers into a highly active sulfonate intermediate through activation treatment, significantly improving surface reactivity and enhancing the binding force with carbon quantum dots.
[0034] After activation treatment, the present invention preferably washes the fabric with acetonitrile and dries it at room temperature to obtain activated cotton fibers.
[0035] The present invention preferably involves immersing activated cotton fibers in a silver-doped carbon quantum dot dispersion, allowing them to stand in the dark for loading, so that the silver-doped carbon quantum dots are adsorbed onto the fiber surface, removing the fibers, and drying them at room temperature to obtain antibacterial cotton fibers based on silver-doped carbon quantum dots.
[0036] The present invention does not impose any special limitation on the concentration of the silver-doped carbon quantum dot dispersion; the concentration can be adjusted according to the requirements to meet the usage ratio.
[0037] In this invention, the mass ratio of the activated cotton fiber to the silver-doped carbon quantum dots in the silver-doped carbon quantum dot dispersion is 1~3g:0.5~2mg, more preferably 1~2g:1~1.5mg; the loading temperature is preferably room temperature, and the loading time is preferably 36~72h, more preferably 48h; the loading is preferably carried out under light-protected and static conditions.
[0038] This invention provides antibacterial cotton fibers based on silver-doped carbon quantum dots prepared by the preparation method described in the above technical solution.
[0039] This invention provides the application of the silver-doped carbon quantum dot-based antibacterial cotton fiber described above in medical textiles, daily textiles, or filter materials. This invention does not specifically limit the method of application; any method well-known in the art can be used.
[0040] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0041] Unless otherwise specified, the experimental methods described in the various embodiments of this invention are conventional methods; unless otherwise specified, the raw materials used are all commercially available products, and the proportions are all by mass percentage.
[0042] In the following examples, the cotton fiber used is cotton linter, which is sourced from the Institute of Economic Crops, Anhui Academy of Agricultural Sciences.
[0043] Example 1
[0044] A 0.1 mol / L aqueous solution of AgNO3 was mixed with a 0.01 mol / L aqueous solution of tryptophan, wherein the volume ratio of AgNO3 solution to tryptophan solution was 1:25. The resulting mixture was placed in a microwave oven and heated at 500 W for 20 minutes. After microwave treatment, the mixture was cooled to room temperature, 10 mL of ultrapure water was added, and the mixture was centrifuged. The mixture was then filtered through a polytetrafluoroethylene syringe filter with a pore size of 0.22 µm to remove large particles. The filtered solution was dialyzed through a dialysis bag (molecular weight cutoff of 500 Da) for 24 h to obtain a silver-doped carbon quantum dot dispersion. Cotton fibers were immersed in a 1 g / L Triton X-100 distilled aqueous solution (the ratio of solution volume to cotton fiber mass was 50 mL: 1 g), heated to 60°C, soaked for 30 minutes, then rinsed with distilled water, and dried in an oven at 45°C for 6 hours to obtain pretreated cotton fibers. Pretreated cotton fibers were immersed in 50 mL of acetonitrile, with a mass ratio of pretreated cotton fibers to acetonitrile of 1:50. Benzenesulfonyl chloride (BSC) and triethylamine (TEA) were added in a mass ratio of 3:4, with a mass ratio of pretreated cotton fibers to benzenesulfonyl chloride of 1:0.05. The mixture was stirred and reacted in the dark at 50 °C and pH=7 for 36 h. The fabric was then washed with acetonitrile and dried at room temperature to obtain activated cotton fibers. Activated cotton fibers were immersed in a silver-doped carbon quantum dot dispersion with a mass ratio of 1 g to 0.5 mg. The mixture was left to stand for 48 hours in the dark, and then the fibers were removed and dried at room temperature to obtain antibacterial cotton fibers based on silver-doped carbon quantum dots.
[0045] Example 2
[0046] A 0.2 mol / L aqueous solution of AgNO3 was mixed with a 0.05 mol / L aqueous solution of tryptophan, wherein the volume ratio of AgNO3 solution to tryptophan solution was 1.5:50. The resulting mixture was placed in a microwave oven and heated at 600 W for 30 minutes. After microwave treatment, the mixture was cooled to room temperature, 10 mL of ultrapure water was added, and the mixture was centrifuged. The mixture was then filtered through a polytetrafluoroethylene syringe filter with a pore size of 0.22 µm to remove large particles. The filtered solution was dialyzed through a dialysis bag (molecular weight cutoff of 1000 Da) for 36 h to obtain a silver-carbon quantum dot dispersion. Cotton fibers were immersed in a 1 g / L Triton X-100 distilled aqueous solution (the ratio of solution volume to cotton fiber mass was 60 mL: 1 g), heated to 60 °C, soaked for 60 minutes, then rinsed with distilled water, and dried in a 60 °C oven for 8 hours to obtain pretreated cotton fibers. Pretreated cotton fibers were immersed in 50 mL of acetonitrile, with a mass ratio of pretreated cotton fibers to acetonitrile of 1:30. Benzenesulfonyl chloride (BSC) and triethylamine (TEA) were added in a mass ratio of 4:5, with a mass ratio of pretreated cotton fibers to benzenesulfonyl chloride of 1:0.1. The mixture was stirred and reacted in the dark at 60 °C and pH=7 for 48 h. The fabric was then washed with acetonitrile and dried at room temperature to obtain activated cotton fibers. Activated cotton fibers were immersed in a silver-doped carbon quantum dot dispersion with a mass ratio of 1g to 2mg. The fibers were left to stand for 48 hours in the dark, then removed and dried at room temperature to obtain antibacterial cotton fibers based on silver-doped carbon quantum dots.
[0047] Example 3
[0048] A 0.1 mol / L aqueous solution of AgNO3 was mixed with a 0.04 mol / L aqueous solution of tryptophan, wherein the volume ratio of AgNO3 solution to tryptophan solution was 1:40. The resulting mixture was placed in a microwave oven and heated at 600 W for 30 minutes. After microwave treatment, the mixture was cooled to room temperature, 10 mL of ultrapure water was added, and the mixture was centrifuged. The mixture was then filtered through a polytetrafluoroethylene syringe filter with a pore size of 0.22 µm to remove large particles. The filtered solution was dialyzed through a dialysis bag (molecular weight cutoff of 1000 Da) for 48 h to obtain a silver-doped carbon quantum dot dispersion. Cotton fibers were immersed in a 1 g / L Triton X-100 distilled aqueous solution (the ratio of solution volume to cotton fiber mass was 100 mL: 1 g), heated to 55°C, soaked for 60 minutes, then rinsed with distilled water, and dried in an oven at 55°C for 8 hours to obtain pretreated cotton fibers. Pretreated cotton fibers were immersed in 50 mL of acetonitrile, with a mass ratio of pretreated cotton fibers to acetonitrile of 1:30. Benzenesulfonyl chloride (BSC) and triethylamine (TEA) were added in a mass ratio of 4:5, with a mass ratio of pretreated cotton fibers to benzenesulfonyl chloride of 1:0.08. The mixture was stirred and reacted in the dark at 50 °C and pH=7 for 48 h. The fabric was then washed with acetonitrile and dried at room temperature to obtain activated cotton fibers. Activated cotton fibers were immersed in a silver-doped carbon quantum dot dispersion with a mass ratio of 1 g to 1 mg. The fibers were then left to stand for 72 hours in the dark, removed, and dried at room temperature to obtain antibacterial cotton fibers based on silver-doped carbon quantum dots.
[0049] Performance testing
[0050] Antimicrobial performance test: The cotton fibers obtained in Examples 1-3 and the untreated cotton fibers were tested for antimicrobial performance according to standard GB / T 20944.3-2008 "Evaluation of antimicrobial properties of textiles - Part 3: Shaking method". Staphylococcus aureus was selected as the test strain.
[0051] Antibacterial rate = (A - B) / A × 100%
[0052] A: Number of viable bacteria in the control group (untreated cotton fibers) after culture; B: The number of viable bacteria in the experimental group (antibacterial cotton fiber to be tested) under the same conditions.
[0053] The test results are shown in Table 1.
[0054] Table 1. Antibacterial rate of antibacterial cotton fibers based on silver-doped carbon quantum dots in Examples 1-3
[0055] As shown in Table 1, the carbon quantum dot antibacterial cotton fiber provided by the present invention has excellent antibacterial properties and is washable, indicating that the antibacterial coating is firmly bonded.
[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing antibacterial cotton fiber based on silver-doped carbon quantum dots, characterized in that, Includes the following steps: The silver salt solution and carbon source solution were mixed and subjected to microwave heat treatment, followed by separation and dialysis to obtain a silver-doped carbon quantum dot dispersion. Cotton fibers are mixed with an aqueous solution of a surfactant for pretreatment to obtain pretreated cotton fibers. The pretreated cotton fibers, benzenesulfonyl chloride, triethylamine and organic solvent are mixed and activated to obtain activated cotton fibers; The activated cotton fibers were impregnated in a silver-doped carbon quantum dot dispersion and loaded to obtain antibacterial cotton fibers based on silver-doped carbon quantum dots.
2. The preparation method according to claim 1, characterized in that, The silver salt in the silver salt solution includes silver nitrate; the carbon source in the carbon source solution includes tryptophan or citric acid; the concentration of the silver salt solution is 0.1~0.2 mol / L; the concentration of the carbon source solution is 0.01~0.05 mol / L. The volume ratio of the silver salt solution to the carbon source solution is 0.5~5:10~100.
3. The preparation method according to claim 1, characterized in that, The microwave heat treatment has a power of 500-800 W and a time of 20-40 min; the dialysis bag used for dialysis has a molecular weight cutoff of 500-1000 Da, and the dialysis time is 24-48 h.
4. The preparation method according to claim 1, characterized in that, The surfactant in the aqueous solution includes Triton X-100; the concentration of the aqueous solution is 0.5~2g / L, and the volume ratio of the aqueous solution to the mass of the cotton fiber is 50~150mL:1g.
5. The preparation method according to claim 1 or 4, characterized in that, The pretreatment temperature is 45~70°C and the time is 20~60 min.
6. The preparation method according to claim 1, characterized in that, The mass ratio of the pretreated cotton fiber to benzenesulfonyl chloride is 1~2:0.05~0.1; the mass ratio of the benzenesulfonyl chloride to triethylamine is 3~4:4~6; and the mass ratio of the pretreated cotton fiber to the organic solvent is 1~2:25~50.
7. The preparation method according to claim 1 or 6, characterized in that, The activation treatment conditions include: pH=7, temperature 45~60℃, and reaction time in the dark 24~72h.
8. The preparation method according to claim 1, characterized in that, The mass ratio of activated cotton fiber to silver-doped carbon quantum dots in the silver-doped carbon quantum dot dispersion is 1~3g:0.5~2mg; the loading temperature is room temperature, and the loading time is 36~72h; the loading is carried out under light-protected and static conditions.
9. The antibacterial cotton fiber based on silver-doped carbon quantum dots prepared by the preparation method according to any one of claims 1 to 8.
10. The application of the antibacterial cotton fiber based on silver-doped carbon quantum dots as described in claim 9 in medical textiles, daily textiles or filter materials.