Antibacterial coating and preparation method thereof
By using a combination of mesoporous silica and modified lycypress seed extraction powder in antibacterial coatings, the problems of unstable antibacterial effect and low adhesion of composite antibacterial coatings are solved, and better durability and corrosion resistance are achieved.
Patent Information
- Application Number
- CN202510872819.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-07-29
AI Technical Summary
Existing composite antibacterial coatings are susceptible to environmental influences, and their antibacterial effects are difficult to maintain for a long time. The coating has low adhesion and poor corrosion resistance.
Mesoporous silica is used as the antibacterial carrier and modified lycose seed extraction powder is used as the filler. By combining modified silver nanoparticles, chitosan quaternary ammonium salt and titanium dioxide nanoparticles, the interface binding force and antibacterial properties of the coating are enhanced.
It improves the durability and antibacterial properties of the coating, reduces the impact on the photothermal environment, and enhances the adhesion and corrosion resistance of the coating.
Smart Images
Figure CN120383855A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of coatings, and particularly relates to an antibacterial coating and a preparation method thereof. Background Art
[0002] Antibacterial coatings are widely used in the fields of architecture, medical treatment, public facilities, daily necessities, food packaging, clothing, etc. They can directly kill or inhibit bacteria, fungi, and viruses, reduce surface contamination, reduce cross-infection, and enhance public health safety. The main types of current antibacterial coatings are: (1) Inorganic antibacterial coatings. Metal ion type: such as silver and copper ions, which act by destroying the microbial cell membrane. Photocatalytic type: Titanium dioxide (TiO2) generates reactive oxygen under light irradiation to decompose microorganisms. Oxide type: Zinc oxide (ZnO) has both antibacterial and ultraviolet protection functions. (2) Organic antibacterial coatings. Quaternary ammonium salts, triclosan, etc., which destroy the cell membrane through charge action but have poor persistence. (3) Natural antibacterial coatings. Chitosan, plant extracts (such as tea tree oil), which are environmentally friendly but have limited antibacterial strength. (4) Composite antibacterial coatings. Combining inorganic / organic materials (such as silver-quaternary ammonium salt composite) to enhance the synergistic effect.
[0003] Among the above types of antibacterial coatings, composite antibacterial coatings are more widely used due to their advantages such as high antibacterial rate, wide antibacterial surface, and good applicability. However, the current composite antibacterial coatings on the market also have the following defects: being easily affected by the environment (light, heat, etc.), and it is difficult to maintain the antibacterial effect for a long time; the composition is relatively complex, and the fusion effect between materials and with the substrate surface is poor, resulting in low coating adhesion and poor corrosion resistance. Summary of the Invention
[0004] The purpose of the present invention is to provide an antibacterial coating and a preparation method thereof, which solve the problems of difficult long-term maintenance of antibacterial effect, low coating adhesion, and poor corrosion resistance existing in the existing antibacterial coatings.
[0005] The present invention achieves the above purpose through the following technical solutions: A preparation method of an antibacterial coating, the steps include: S1. Take silver nanoparticles and perform modification treatment with a silane coupling agent to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt, add deionized water to make the solid-liquid ratio 1:8 - 10, ultrasonically disperse and then dry and grind to obtain antibacterial powder with a particle size of 10 - 20 μm, add the antibacterial powder to 0.8 - 1.2 times the mass of ethylene glycol, and ultrasonically disperse again to obtain an antibacterial material; S3. Add aqueous acrylic resin to a reaction kettle, heat up to 38 - 42 °C, and sequentially add a dispersant, a wetting agent, and an antifoaming agent, and stir and dissolve to obtain a resin material; S4. Prepare the modified Ficus pumila seed extract powder. Mix the nano kaolin and the modified Ficus pumila seed extract powder at a mass ratio of 4 - 6:1, add deionized water to make the solid-liquid ratio 1:4 - 6, then control the temperature at 45 - 50 °C, and shear and disperse at a rotation speed of 6000 - 8000 rpm for 30 - 35 min to obtain the filler; S5. First, mix the antibacterial agent into the resin material and stir at a rotation speed of 300 - 400 rpm. Then, mix the filler into the resin material, increase the stirring speed to 550 - 600 rpm, and continue for 50 - 60 min. Then, let it stand for 20 - 30 h to obtain the initial coating product; S6. Adjust the pH of the initial coating product to 8.5 ± 0.2 with ammonia water, and then filter it through a 380 - 420 mesh sieve to obtain the antibacterial coating.
[0006] Further improvement lies in that the specific operation of step S1 is: Take silver nanoparticles, mix them with 3 - aminopropyltriethoxysilane at a mass ratio of 1:0.1 - 0.2, stir and process in a water bath at 55 - 65 °C at a rotation speed of 500 - 600 rpm for 1.5 - 2.5 h, then centrifuge and wash with ethanol, and dry to obtain the modified silver nanoparticles.
[0007] Further improvement lies in that in step S2, the mixing mass ratio among the mesoporous silica, the modified silver nanoparticles, the titanium dioxide nanoparticles, and the chitosan quaternary ammonium salt is 5:1.5 - 2:2.5 - 3.5:2 - 2.5.
[0008] Further improvement lies in that in step S2, the power of both ultrasonic dispersions is 280 - 320 W, and the time is 25 - 35 min.
[0009] Further improvement lies in that in step S3, the rotation speed of the stirring and dissolving is 180 - 220 rpm, and the time is 25 - 30 min.
[0010] Further improvement lies in that in step S3, the dispersant is selected from one of sodium polyacrylate, polyoxyethylene ether, sodium hexametaphosphate, or sodium lignosulfonate, the wetting agent is selected from one of polyether-modified silicone, glycerol, or alkynediol, the defoaming agent is selected from one of silicone, polypropylene glycol glycerol ether, or tributyl phosphate, and the addition amounts of the dispersant, the wetting agent, and the defoaming agent in the resin material respectively account for 1.8 - 2.2%, 0.8 - 1.2%, and 0.4 - 0.6% of the waterborne acrylic resin.
[0011] Further improvement lies in that in step S4, the specific operation of preparing the modified Ficus pumila seed extract powder is: To prepare Ficus pumila L. fruit grains, add a citric acid buffer solution with a pH of 4.2 - 4.5 at a solid-liquid ratio of 1:10 - 12 g / mL, then add pectin esterase accounting for 0.6 - 1.2 U / g of the grain content, and carry out a constant-temperature stirring reaction at 48 - 52 °C for 2 - 2.5 h. Raise the temperature to 85 - 90 °C and keep it warm for 10 - 12 min, then filter to obtain the grains, wash and dry them; Add deionized water at 50 - 60 °C to the grains at a solid-liquid ratio of 1:12 - 15 g / mL, and carry out a constant-temperature water bath stirring extraction at 200 - 300 rpm for 20 - 25 min to obtain an aqueous extract; Vacuum concentrate the aqueous extract at 50 - 60 °C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 55 - 60%, let it stand for 1 - 2 h and then filter it dry. Wash the filter cake with alcohol with a mass concentration of 55 - 60% and 95% until no chloride ions are contained to obtain an extract. Finally, vacuum dry the extract at 55 - 60 °C, pulverize it, and obtain the modified Ficus pumila L. seed extract powder.
[0012] The further improvement lies in that the specific operation of preparing Ficus pumila L. fruit grains is as follows: Take mature Ficus pumila L. fruits, remove the fruit stalks and impurities, air-dry them until the moisture content is 8 - 12%, then roll them to separate the pericarp from the grains, sieve to obtain the grains, and carry out hot air circulation at 105 - 110 °C for 3 - 5 min and then cool them.
[0013] The further improvement lies in that in step S5, the mass ratio of the antibacterial material, the filler, and the resin material is 10:12 - 15:45 - 50.
[0014] The present invention also provides an antibacterial coating, which is prepared by the above preparation method.
[0015] The beneficial effects of the present invention are as follows: The present invention uses mesoporous silica as an antibacterial carrier and also uses modified Ficus pumila L. seed extract powder as a cooperating filler. Its own degree of methylation is low, the molecular weight range is narrow, and the stability is better. At the same time, through enzyme-assisted de-esterification modification treatment, the degree of esterification is further reduced, the number of free carboxyl groups increases, the hydrogen bond interaction with the waterborne acrylic resin is enhanced, the interfacial binding force and the coating adhesion are enhanced, thereby improving the corrosion resistance of the coating, reducing the influence of the light and heat environment on the antibacterial property of the coating, and improving the durability. In addition, the carboxyl group can complex with metal ions (such as Ag ＋ ), assisting in enhancing the antibacterial performance. Description of the Drawings
[0016] Figure 1 It is the colony map obtained after treating Escherichia coli in the antibacterial experiments of each experimental group; Figure 2 It is the colony map obtained after treating Staphylococcus aureus in the antibacterial experiments of each experimental group. Detailed Embodiments
[0017] The present application will be further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0018] I. Main materials Silver nanoparticles: with a particle size of 20 - 30 nm, purchased from Shanghai Pantian Powder Materials Co., Ltd.; Mesoporous silica: with a particle size of 100 - 200 nm and a pore diameter of 10 - 40 nm, purchased from Zhongke Leiming Technology Co., Ltd.; Titanium dioxide nanoparticles: type DK405, with a particle size of about 15 nm, purchased from Zhongke Leiming Technology Co., Ltd.; Chitosan quaternary ammonium salt: HACC - 02, purchased from Lanli Biotechnology (Xi'an) Co., Ltd.; Water - based acrylic resin: purchased from Guangzhou Changhao Trading Co., Ltd.; Ficus pumila: mature Ficus pumila fruits, purchased from Jishou, Hunan; Nano kaolin: 15000 mesh, purchased from Guangdong Senxin Industry and Trade Co., Ltd.
[0019] II. Implementation experiments Example 1 A preparation method of an antibacterial coating, the steps include: S1. Take silver nanoparticles, mix them with 3 - aminopropyltriethoxysilane according to a mass ratio of 1:0.1, stir - process in a water bath at 55°C at a rotation speed of 500 rpm for 2.5 h, then perform centrifugal separation and wash with ethanol, and dry to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt according to a mass ratio of 5:1.5:2.5:2, add deionized water to make the solid - liquid ratio 1:8, perform ultrasonic dispersion (power 280 W, time 35 min), then dry and grind to obtain an antibacterial powder with a particle size of about 10 μm. Add the antibacterial powder to 0.8 times its mass of ethylene glycol, and perform ultrasonic dispersion again (power 280 W, time 35 min) to obtain an antibacterial material; S3. Add the water - based acrylic resin to the reaction kettle, heat up to 38°C, and sequentially add sodium polyacrylate accounting for 1.8% of the mass of the water - based acrylic resin, polyether - modified silicone accounting for 0.8%, and silicone accounting for 0.4%, stir and dissolve, and the rotation speed for stirring and dissolving is 180 rpm and the time is 30 min to obtain a resin material; S4. Prepare the modified Ficus pumila seed extract powder. Mix the nano kaolin and the modified Ficus pumila seed extract powder at a mass ratio of 4:1, add deionized water to make the solid-liquid ratio 1:4, then control the temperature at 45 °C and shear and disperse at a speed of 6000 rpm for 35 min to obtain the filler; Among them, the specific operation for preparing the modified Ficus pumila seed extract powder is as follows: Take mature Ficus pumila fruits, remove the fruit stalks and impurities, air-dry until the moisture content is 8%, then roll to separate the pericarp from the seeds, sieve to obtain the seeds, subject the seeds to hot air circulation at 105 °C for 5 min and then cool, add citric acid buffer solution with a pH of 4.2 according to a solid-liquid ratio of 1:10 g / mL, add pectin esterase accounting for 0.6 U / g of the seed content, stir and react at a constant temperature of 48 °C for 2.5 h, raise the temperature to 85 °C and keep warm for 12 min, then filter to obtain the seeds, wash and dry; Add deionized water at 50 °C to the seeds according to a solid-liquid ratio of 1:12 g / mL, stir and extract at a constant temperature of 200 rpm for 25 min to obtain the water extract; Vacuum concentrate the water extract at 50 °C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 55%, let it stand for 1 h and then filter and dry, wash the filter cake with alcohol with a mass concentration of 55% and 95% until no chloride ions are contained to obtain the extract, and finally vacuum dry the extract at 55 °C, pulverize to obtain the modified Ficus pumila seed extract powder; S5. First mix the antibacterial material into the resin material and stir at a speed of 300 rpm, then mix the filler into the resin material, raise the stirring speed to 550 rpm and continue for 60 min, then let it stand for 20 h to obtain the initial coating product; the mass ratio of the antibacterial material, the filler, and the resin material is 10:12:45; S6. Adjust the pH of the initial coating product to 8.3 with ammonia water, and then filter through a 380-mesh sieve to obtain the antibacterial coating.
[0020] Example 2 A preparation method of an antibacterial coating, the steps include: Take silver nanoparticles, mix them with 3-aminopropyltriethoxysilane at a mass ratio of 1:0.15, stir and process in a water bath at 60 °C at a speed of 550 rpm for 2 h, then centrifuge and separate, wash with ethanol, and dry to obtain modified silver nanoparticles; Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt at a mass ratio of 5:1.8:3:2.2, add deionized water to make the solid-liquid ratio 1:9, ultrasonically disperse (power 300 W, time 30 min), then dry and grind to obtain an antibacterial powder with a particle size of about 15 μm, add the antibacterial powder to 1 times its mass of ethylene glycol, and ultrasonically disperse again (power 300 W, time 30 min) to obtain the antibacterial material; S3. Add the waterborne acrylic resin to the reaction kettle, heat up to 40 °C, and sequentially add sodium hexametaphosphate accounting for 2% of the mass of the waterborne acrylic resin, glycerol accounting for 1%, and polyoxypropylene glycerol ether accounting for 0.5%. Stir and dissolve at a rotation speed of 200 rpm for 28 min to obtain a resin material; S4. Prepare the modified Ficus pumila seed extract powder. Mix the nano kaolin and the modified Ficus pumila seed extract powder at a mass ratio of 5:1, add deionized water to make the solid-liquid ratio 1:5, then control the temperature at 48 °C, and shear and disperse at a rotation speed of 7000 rpm for 32 min to obtain a filler; Among them, the specific operation for preparing the modified Ficus pumila seed extract powder is as follows: Take mature Ficus pumila fruits, remove the fruit stalks and impurities, air-dry until the moisture content is 10%, then roll to separate the pericarp from the seeds, sieve to obtain the seeds, perform hot air circulation at 108 °C for 4 min and then cool the seeds. Add a citric acid buffer solution with a pH of 4.4 at a solid-liquid ratio of 1:11 g / mL, and then add pectin esterase accounting for 1 U / g of the seed content. Stir and react at a constant temperature of 50 °C for 2.2 h, heat up to 88 °C and keep warm for 11 min, then filter to obtain the seeds, wash and dry; Add deionized water at 55 °C to the seeds at a solid-liquid ratio of 1:14 g / mL, and stir and extract at a constant water bath rotation speed of 250 rpm for 22 min to obtain an aqueous extract; Vacuum concentrate the aqueous extract at 55 °C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 58%. Let it stand for 1.5 h and then filter and dry. Wash the filter cake with alcohol with a mass concentration of 58% and 95% respectively until no chloride ions are contained to obtain an extract. Finally, place the extract in a vacuum drying environment at 58 °C, pulverize to obtain the modified Ficus pumila seed extract powder; S5. First, mix the antibacterial material into the resin material and stir at a rotation speed of 350 rpm. Then mix the filler into the resin material, increase the stirring rotation speed to 580 rpm, and continue for 55 min. Then let it stand for 25 h to obtain a primary coating product; the mass ratio of the antibacterial material, the filler, and the resin material is 10:13:48; S6. Adjust the pH of the primary coating product to 8.5 with ammonia water, and then filter through a 400-mesh sieve to obtain the antibacterial coating.
[0021] Example 3 A preparation method of an antibacterial coating, the steps include: Take silver nanoparticles, mix them with 3-aminopropyltriethoxysilane at a mass ratio of 1:0.2, stir and process in a water bath at 65 °C at a rotation speed of 600 rpm for 1.5 h, then perform centrifugal separation and wash with ethanol, and dry to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and quaternary ammonium salt of chitosan in a mass ratio of 5:2:3.5:2.5. Add deionized water to make the solid-liquid ratio 1:10. After ultrasonic dispersion (power 320 W, time 25 min), dry and grind to obtain antibacterial powder with a particle size of about 20 μm. Add the antibacterial powder to ethylene glycol with a mass 1.2 times that of the powder, and ultrasonic disperse again (power 320 W, time 25 min) to obtain an antibacterial material; S3. Add waterborne acrylic resin to a reaction kettle, heat up to 42 °C, and successively add sodium lignosulfonate accounting for 2.2% of the mass of the waterborne acrylic resin, alkynediol accounting for 1.2%, and tributyl phosphate accounting for 0.6%. Stir to dissolve at a rotation speed of 220 rpm for 25 min to obtain a resin material; S4. Prepare modified Ficus pumila seed extract powder. Mix nano kaolin and modified Ficus pumila seed extract powder in a mass ratio of 6:1. Add deionized water to make the solid-liquid ratio 1:6, then control the temperature at 50 °C and shear disperse at a rotation speed of 8000 rpm for 30 min to obtain a filler; Among them, the specific operation for preparing the modified Ficus pumila seed extract powder is as follows: Take mature Ficus pumila fruits, remove the fruit stalks and impurities, air-dry to a moisture content of 12%, then roll to separate the pericarp from the seeds, sieve to obtain the seeds. Subject the seeds to hot air circulation at 110 °C for 3 min and then cool. Add a citric acid buffer solution with a pH of 4.5 at a solid-liquid ratio of 1:12 g / mL, and then add pectin esterase accounting for 1.2 U / g of the seed content. Stir and react at a constant temperature of 52 °C for 2 h, heat up to 90 °C and keep warm for 10 min, then filter to obtain the seeds, wash and dry; Add deionized water at 60 °C to the seeds at a solid-liquid ratio of 1:15 g / mL, and stir and extract at a constant temperature of 300 rpm for 20 min to obtain an aqueous extract; Vacuum concentrate the aqueous extract at 60 °C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 60%. Let it stand for 2 h and then filter and dry. Wash the filter cake with alcohol with a mass concentration of 60% and 95% until no chloride ions are contained to obtain an extract. Finally, place the extract in a vacuum drying environment at 60 °C, pulverize to obtain the modified Ficus pumila seed extract powder; S5. First, mix the antibacterial material into the resin material and stir at a rotation speed of 400 rpm. Then mix the filler into the resin material, increase the stirring speed to 600 rpm, and continue for 50 min. Then let it stand for 30 h to obtain a preliminary coating product; the mass ratio of the antibacterial material, filler, and resin material is 10:15:50; S6. Adjust the pH of the preliminary coating product to 8.7 with ammonia water, and then filter through a 420-mesh sieve to obtain the antibacterial coating.
[0022] Comparative Example 1 A preparation method of an antibacterial coating, the steps including: S1. Take silver nanoparticles, mix them with 3-aminopropyltriethoxysilane according to a mass ratio of 1:0.15, stir and process them in a water bath at 60 °C at a rotation speed of 550 rpm for 2 h, then perform centrifugal separation and wash with ethanol, and dry to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt according to a mass ratio of 5:1.8:3:2.2, add deionized water to make the solid-liquid ratio 1:9, perform ultrasonic dispersion (power 300 W, time 30 min), and then obtain an antibacterial powder with a particle size of about 15 μm after drying and grinding. Add the antibacterial powder to ethylene glycol with a mass of 1 time, and perform ultrasonic dispersion again (power 300 W, time 30 min) to obtain an antibacterial material; S3. Add waterborne acrylic resin to a reaction kettle, heat up to 40 °C, and sequentially add sodium hexametaphosphate accounting for 2% of the mass of the waterborne acrylic resin, glycerol accounting for 1%, and polyoxypropylene glycerol ether accounting for 0.5%, stir and dissolve, and the rotation speed for stirring and dissolving is 200 rpm and the time is 28 min to obtain a resin material; S4. Take nano kaolin, add deionized water to make the solid-liquid ratio 1:5, then control the temperature at 48 °C, and perform shear dispersion at a rotation speed of 7000 rpm for 32 min to obtain a filler; S5. First mix the antibacterial material into the resin material, stir at a rotation speed of 350 rpm at the same time, then mix the filler into the resin material, increase the stirring speed to 580 rpm, and continue for 55 min, and then stand for 25 h to obtain a preliminary coating product; the mass ratio of the antibacterial material, the filler, and the resin material is 10:13:48; S6. Adjust the pH of the preliminary coating product to 8.5 with ammonia water, and then filter through a 400-mesh sieve to obtain the antibacterial coating.
[0023] Comparative Example 2 A preparation method of an antibacterial coating, the steps including: S1. Take silver nanoparticles, mix them with 3-aminopropyltriethoxysilane according to a mass ratio of 1:0.15, stir and process them in a water bath at 60 °C at a rotation speed of 550 rpm for 2 h, then perform centrifugal separation and wash with ethanol, and dry to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt according to a mass ratio of 5:1.8:3:2.2, add deionized water to make the solid-liquid ratio 1:9, perform ultrasonic dispersion (power 300 W, time 30 min), and then obtain an antibacterial powder with a particle size of about 15 μm after drying and grinding. Add the antibacterial powder to ethylene glycol with a mass of 1 time, and perform ultrasonic dispersion again (power 300 W, time 30 min) to obtain an antibacterial material; S3. Add the waterborne acrylic resin to the reaction kettle, heat up to 40 °C, and successively add sodium hexametaphosphate accounting for 2% of the mass of the waterborne acrylic resin, glycerol accounting for 1%, and polyoxypropylene glycerol ether accounting for 0.5%. Stir and dissolve at a stirring speed of 200 rpm for 28 min to obtain a resin material; S4. Prepare the modified fig seed extract powder. Mix the nano kaolin and the modified fig seed extract powder at a mass ratio of 5:1, add deionized water to make the solid-liquid ratio 1:5, then control the temperature at 48 °C, and shear and disperse at a speed of 7000 rpm for 32 min to obtain a filler; Among them, the specific operation for preparing the modified fig seed extract powder is as follows: Take mature fig fruits, remove the fruit stalks and impurities, air-dry until the moisture content is 10%, then roll to separate the peel and seeds, sieve to obtain the seeds, perform hot air circulation at 108 °C for 4 min and then cool, add a citric acid buffer solution with a pH of 4.4 according to a solid-liquid ratio of 1:11 g / mL, then add pectin esterase accounting for 1 U / g of the seed content, stir and react at a constant temperature of 50 °C for 2.2 h, heat up to 88 °C and keep warm for 11 min, then filter to obtain the seeds, wash and dry; Add deionized water at 55 °C to the seeds according to a solid-liquid ratio of 1:14 g / mL, and stir and extract at a constant water bath of 250 rpm for 22 min to obtain an aqueous extract; Vacuum concentrate the aqueous extract at 55 °C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 58%, let it stand for 1.5 h and then filter and dry. Wash the filter cake with alcohol with a mass concentration of 58% and 95% until no chloride ions are contained to obtain an extract. Finally, place the extract in a vacuum drying environment at 58 °C, pulverize, and obtain the modified fig seed extract powder; S5. First, mix the antibacterial material into the resin material and stir at a speed of 350 rpm. Then mix the filler into the resin material, increase the stirring speed to 580 rpm, and continue for 55 min. Then let it stand for 25 h to obtain a preliminary coating product; the mass ratio of the antibacterial material, the filler, and the resin material is 10:13:48; S6. Adjust the pH of the preliminary coating product to 8.5 with ammonia water, and then filter through a 400-mesh sieve to obtain the antibacterial coating.
[0024] Comparative Example 3 A preparation method of an antibacterial coating, the steps include: Take silver nanoparticles, mix them with 3-aminopropyltriethoxysilane at a mass ratio of 1:0.15, stir and process in a water bath at 60 °C at a speed of 550 rpm for 2 h, then perform centrifugal separation and wash with ethanol, and dry to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and quaternary ammonium salt of chitosan in a mass ratio of 5:1.8:3:2.2. Add deionized water to make the solid-liquid ratio 1:9. After ultrasonic dispersion (power 300 W, time 30 min), dry and grind to obtain antibacterial powder with a particle size of about 15 μm. Add the antibacterial powder to ethylene glycol with a mass 1 time that of the powder, and ultrasonically disperse again (power 300 W, time 30 min) to obtain an antibacterial material; S3. Add waterborne acrylic resin to a reaction kettle, heat up to 40 °C, and successively add sodium hexametaphosphate accounting for 2% of the mass of the waterborne acrylic resin, glycerol 1%, and polyoxypropylene glycerol ether 0.5%. Stir and dissolve at a rotation speed of 200 rpm for 28 min to obtain a resin material; S4. Prepare Ficus pumila seed extract powder. Mix nano kaolin and Ficus pumila seed extract powder in a mass ratio of 5:1. Add deionized water to make the solid-liquid ratio 1:5, and then control the temperature at 48 °C and shear and disperse at a rotation speed of 7000 rpm for 32 min to obtain a filler; Among them, the specific operation for preparing Ficus pumila seed extract powder is as follows: Take mature Ficus pumila fruits, remove the fruit stalks and impurities, air-dry until the moisture content is 10%, then roll to separate the pericarp from the seeds, sieve to obtain the seeds, and carry out hot air circulation at 108 °C for 4 min and then cool; Add deionized water at 55 °C to the seeds at a solid-liquid ratio of 1:14 g / mL, and stir and extract at a constant temperature water bath of 250 rpm for 22 min to obtain an aqueous extract; Vacuum concentrate the aqueous extract at 55 °C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 58%, let stand for 1.5 h and then filter dry. Wash the filter cake with alcohol with a mass concentration of 58% and 95% until no chloride ions are contained to obtain an extract. Finally, place the extract in a vacuum drying environment at 58 °C, pulverize to obtain the modified Ficus pumila seed extract powder; S5. First, mix the antibacterial material into the resin material and stir at a rotation speed of 350 rpm. Then mix the filler into the resin material, increase the stirring speed to 580 rpm, and continue for 55 min, and then let stand for 25 h to obtain a preliminary coating product; the mass ratio of the antibacterial material, filler, and resin material is 10:13:48; S6. Adjust the pH of the preliminary coating product to 8.5 with ammonia water, and then filter through a 400-mesh sieve to obtain the antibacterial coating.
[0025] Comparative Example 4 A preparation method of an antibacterial coating, the steps include: S1. Take silver nanoparticles, mix them with 3-aminopropyltriethoxysilane at a mass ratio of 1:0.15, stir-treat them in a 60°C water bath at a rotation speed of 550 rpm for 2 h, then perform centrifugal separation and wash with ethanol, and dry to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt at a mass ratio of 5:1.8:3:2.2, add deionized water to make the solid-liquid ratio 1:9, perform ultrasonic dispersion (power 300 W, time 30 min), then dry and grind to obtain antibacterial powder with a particle size of about 15 μm. Add the antibacterial powder to 1-fold mass of ethylene glycol and perform ultrasonic dispersion again (power 300 W, time 30 min) to obtain an antibacterial material; S3. Add waterborne acrylic resin to a reaction kettle, heat up to 40°C, and sequentially add sodium hexametaphosphate accounting for 2% of the mass of the waterborne acrylic resin, glycerol accounting for 1%, and polyoxypropylene glycerol ether accounting for 0.5%, stir and dissolve, and the rotation speed for stirring and dissolving is 200 rpm and the time is 28 min to obtain a resin material; S4. Prepare modified Ficus pumila seed extract powder. Mix nano kaolin and modified Ficus pumila seed extract powder at a mass ratio of 1:1, add deionized water to make the solid-liquid ratio 1:5, then control the temperature at 48°C and perform shear dispersion at a rotation speed of 7000 rpm for 32 min to obtain a filler; Among them, the specific operation for preparing the modified Ficus pumila seed extract powder is as follows: Take mature Ficus pumila fruits, remove the fruit stalks and impurities, air-dry them until the moisture content is 10%, then roll them to separate the pericarp from the seeds, sieve to obtain the seeds, perform hot air circulation at 108°C for 4 min and then cool the seeds, add a citric acid buffer solution with a pH of 4.4 at a solid-liquid ratio of 1:11 g / mL, and then add pectin esterase accounting for 1 U / g of the seed content, perform constant-temperature stirring reaction at 50°C for 2.2 h, heat up to 88°C and keep warm for 11 min, then filter to obtain the seeds, wash and dry them; Add deionized water at 55°C to the seeds at a solid-liquid ratio of 1:14 g / mL, perform constant-temperature water bath stirring extraction at 250 rpm for 22 min to obtain an aqueous extract; Vacuum-concentrate the aqueous extract at 55°C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 58%, let it stand for 1.5 h and then filter it dry. Wash the filter cake with alcohol with a mass concentration of 58% and 95% until no chloride ions are contained to obtain an extract. Finally, place the extract in a vacuum drying environment at 58°C, pulverize it to obtain the modified Ficus pumila seed extract powder; S5. First, mix the antibacterial material into the resin material and stir at a rotation speed of 350 rpm, then mix the filler into the resin material, increase the stirring rotation speed to 580 rpm and continue for 55 min, then let it stand for 25 h to obtain a primary coating product; the mass ratio of the antibacterial material, filler, and resin material is 10:13:48; S6. Adjust the pH of the initial coating product to 8.5 with ammonia water, and then filter it through a 400-mesh sieve to obtain the antibacterial coating.
[0026] III. Performance Testing Take the antibacterial coatings prepared in Example 2 and Comparative Examples 1-4 above, prepare coating samples that meet the corresponding standards and have the same specifications, and conduct the following performance tests on them: (1) Coating Adhesion Test This test refers to the standard of GB / T9286-1998 "Cross-Cut Test for Paint and Varnish Films". Use rosin paraffin to protect the edges and back of the sample coating, immerse different coatings in 3.5% NaCl at room temperature of 20°C. Conduct adhesion grade tests on the sample coatings at different times in the soaking water, and conduct adhesion experiments on the sample coatings at 0h, 72h, 168h, and 720h respectively. The grade evaluation criteria refer to Table 1 below: Table 1: Adhesion Grade Evaluation Criteria
[0027] (2) Resistance to Media and Salt Spray Resistance Test Adopt the standard of GB / T1763-1979(89) "Determination Method for Resistance of Paint Films to Chemical Reagents" to test the water resistance, acid resistance, and alkali resistance of the coating samples. The test media are: 3.5% NaCl solution, 10% NaOH solution, and 10% H2SO4 solution. Before testing, use rosin paraffin to seal the edges of the back and sides of the coating. The situation of the back is not used as the basis for assessment. Two-thirds of the area of the coating sample plate needs to be immersed in a beaker containing the corrosive medium, and it is placed in a constant temperature water bath to maintain 25±1°C. After the specified time, take it out, dry the surface of the coating with a paper towel, observe whether there are any damage conditions such as peeling, wrinkling, and rusting, and record the time.
[0028] Adopt the standard of GB / T1771-91 "Determination of Resistance of Paints and Varnishes to Neutral Salt Spray" and use a salt spray test chamber to conduct salt spray resistance tests on the prepared sample coatings. The back and periphery of the sample coatings are coated with paraffin to ensure the influence of other conditions on the sample coatings. The configured NaCl concentration is 50g / L, the pH value is 6.8, it is injected into the equipment, and the test coatings are sprayed by a spraying device so that the salt spray completely covers and settles on the surface of the coating. The temperature requirement in the salt spray chamber is 35±2°C. Check the sample coatings once every 24h, observe whether there are any phenomena such as bulging and peeling on the surface, and record the time.
[0029] (3) Antibacterial Performance Test First, the coating was aged by ultraviolet light irradiation. Specifically, an ultraviolet lamp with a power of 30 W and a wavelength of 253.7 nm was used. The antibacterial coating test plate was fixed at a position 1 m away from the ultraviolet lamp and continuously irradiated for 100 h, and then the antibacterial rate was measured. When measuring the antibacterial rate, Escherichia coli and Staphylococcus aureus were used as the bacterial strains respectively. According to the standard of GB / T 21866—2008, the antibacterial performance of the coating was measured, and the bacteriostatic rate was measured by the plate coating counting method. After the petri dishes were cultured in a constant temperature incubator (37 °C) for 18 h, they were taken out, photographed, and the number of colonies was recorded, and the antibacterial rate was analyzed. The antibacterial rate was calculated according to the following formula:
[0030] In the formula: A and B are the average numbers of colonies on the plates of the blank group and the sample group respectively.
[0031] IV. Result Analysis (1) Coating Adhesion Test The coating adhesion test results of the above Example 2 and Comparative Examples 1-4 are shown in Table 2 below: Table 2: Coating Adhesion Grade
[0032] (2) Medium Resistance and Salt Spray Resistance Test The medium resistance and salt spray resistance test results of the above Example 2 and Comparative Examples 1-4 are shown in Table 3 below: Table 3: Medium Resistance and Salt Spray Resistance Time
[0033] (3) Antibacterial Performance Test The colony photos of the petri dishes of the above Example 2 and Comparative Examples 1-4 after 18 h of culture are as Figure 1 and Figure 2 shown. In addition, the colony number results of Escherichia coli and Staphylococcus aureus are shown in Table 4 below: Table 4: Colony Numbers of Escherichia coli and Staphylococcus aureus
[0034] Analysis: Referring to Tables 2-4 above and Figure 1 and Figure 2, the antibacterial coating prepared in Example 2 of the present invention exhibits excellent adhesion, resistance to media, salt spray resistance and antibacterial performance. Among them, the adhesion grade is S0 before 168h and reaches S1 grade at 720h. The duration for 10% H2SO4 is 94d, for 10% NaOH is 120 + d (the test was only carried out for 120d), for 3.5% NaCl is 120 + d, and for 5% NaCl salt spray is 62d. After aging treatment, the antibacterial rate against Escherichia coli reaches more than 99.5%, and the antibacterial rate against Staphylococcus aureus reaches more than 99.6%.
[0035] Comparative Examples 1-4 are all adjustments based on Example 2. Among them: In Comparative Example 1, only nano kaolin was used in the filler, and modified Ficus pumila seed extract powder was not used for compounding. Its adhesion performance decreased significantly compared with Example 2, and the duration of resistance to media and salt spray also decreased significantly. The antibacterial rate against Escherichia coli dropped to 85.4%, and the antibacterial rate against Staphylococcus aureus dropped to 85.6%; In Comparative Example 2, the modified Ficus pumila seed extract powder was replaced with modified Ficus carica seed extract powder of the same subgenus in the filler. Its adhesion performance decreased to a certain extent compared with Example 2, and the duration of resistance to media and salt spray decreased to a certain extent. The antibacterial rate against Escherichia coli dropped to 92.9%, and the antibacterial rate against Staphylococcus aureus dropped to 93.0%; In Comparative Example 3, no enzyme-assisted de-esterification modification treatment was carried out when preparing the Ficus pumila seed extract powder. Its adhesion performance decreased to a certain extent compared with Example 2, and the duration of resistance to media and salt spray decreased to a certain extent. The antibacterial rate against Escherichia coli dropped to 93.2%, and the antibacterial rate against Staphylococcus aureus dropped to 93.6%; In Comparative Example 4, the dosage of the modified Ficus pumila seed extract powder was increased in the filler, so that the dosage ratio with nano kaolin reached 1:1, resulting in a significant decrease in adhesion performance compared with Example 2, and the duration of resistance to media and salt spray also decreased significantly. The antibacterial rate against Escherichia coli dropped to 85.1%, and the antibacterial rate against Staphylococcus aureus dropped to 85.4%.
[0036] This shows that compounding with modified Ficus pumila seed extract powder can achieve unexpected effects, and the enzyme-assisted de-esterification modification treatment also plays a key role. In addition, when compounding the modified Ficus pumila seed extract powder, a suitable compounding ratio is required. Excessive addition of the modified Ficus pumila seed extract powder will have a negative impact, especially on antibacterial properties, and is even slightly inferior to not adding the modified Ficus pumila seed extract powder.
[0037] The above embodiments only represent several implementation modes of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.
Claims
1. A method for preparing an antibacterial coating, characterized in that the steps Including: S1. Modify silver nanoparticles with a silane coupling agent to obtain modified silver nanoparticles; S2. Mix mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt, add deionized water to make the solid-liquid ratio 1:8 - 10, ultrasonically disperse, then dry and grind to obtain antibacterial powder with a particle size of 10 - 20 μm. Add the antibacterial powder to 0.8 - 1.2 times the mass of ethylene glycol, and ultrasonically disperse again to obtain an antibacterial material; S3. Add waterborne acrylic resin to a reaction kettle, heat up to 38 - 42 °C, sequentially add a dispersant, a wetting agent, and an antifoaming agent, and stir to dissolve to obtain a resin material; S4. Prepare modified Ficus pumila seed extract powder, mix nano kaolin and modified Ficus pumila seed extract powder at a mass ratio of 4 - 6:1, add deionized water to make the solid-liquid ratio 1:4 - 6, then control the temperature at 45 - 50 °C, and shear and disperse at a speed of 6000 - 8000 rpm for 30 - 35 min to obtain a filler; S5. First, mix the antibacterial material into the resin material, and stir at a speed of 300 - 400 rpm. Then, mix the filler into the resin material, increase the stirring speed to 550 - 600 rpm, and continue for 50 - 60 min. Then, let it stand for 20 - 30 h to obtain a preliminary coating product; S6. Adjust the pH of the preliminary coating product to 8.5 ± 0.2 with ammonia water, and then filter through a 380 - 420 mesh sieve to obtain the antibacterial coating.
2. The preparation method of the antibacterial coating according to claim 1, characterized in that, The specific operation of step S1 is as follows: Take silver nanoparticles, mix them with 3-aminopropyltriethoxysilane at a mass ratio of 1:0.1 - 0.2, stir and process in a water bath at 55 - 65 °C at a speed of 500 - 600 rpm for 1.5 - 2.5 h, then centrifuge and wash with ethanol, and dry to obtain modified silver nanoparticles.
3. The preparation method of the antibacterial coating according to claim 1, characterized in that, In step S2, the mixing mass ratio of the mesoporous silica, modified silver nanoparticles, titanium dioxide nanoparticles, and chitosan quaternary ammonium salt is 5:1.5 - 2:2.5 - 3.5:2 - 2.
5.
4. The preparation method of the antibacterial coating according to claim 1, characterized in that, In step S2, the power of both ultrasonic dispersions is 280 - 320 W, and the time is 25 - 35 min.
5. The preparation method of the antibacterial coating according to claim 1, characterized in that, In step S3, the stirring speed for dissolution is 180 - 220 rpm, and the time is 25 - 30 min.
6. The preparation method of the antibacterial coating according to claim 1, characterized in that, In step S3, the dispersant is selected from one of sodium polyacrylate, polyoxyethylene ether, sodium hexametaphosphate, or sodium lignosulfonate; the wetting agent is selected from one of polyether-modified silicone, glycerol, or alkynediol; the antifoaming agent is selected from one of silicone, polypropylene glycol glycerol ether, or tributyl phosphate. And the addition amounts of the dispersant, wetting agent, and antifoaming agent in the resin material respectively account for 1.8 - 2.2%, 0.8 - 1.2%, and 0.4 - 0.6% of the waterborne acrylic resin.
7. The preparation method of the antibacterial coating according to claim 1, wherein, In step S4, the specific operation for preparing the modified Ficus pumila seed extract powder is as follows: To prepare Ficus pumila L. fruit seeds, add a citric acid buffer solution with a pH of 4.2 - 4.5 at a solid-liquid ratio of 1:10 - 12 g / mL, then add pectin esterase accounting for 0.6 - 1.2 U / g of the seed content, and carry out a constant-temperature stirring reaction at 48 - 52 °C for 2 - 2.5 h. Raise the temperature to 85 - 90 °C and keep it warm for 10 - 12 min, then filter to obtain the seeds, wash and dry them; Add deionized water at 50 - 60 °C to the seeds at a solid-liquid ratio of 1:12 - 15 g / mL, and carry out a constant-temperature water bath stirring extraction at 200 - 300 rpm for 20 - 25 min to obtain an aqueous extract; Vacuum concentrate the aqueous extract at 50 - 60 °C, then add alcohol for precipitation to make the alcohol mass concentration of the mixed solution 55 - 60%, let it stand for 1 - 2 h and then filter it dry. Wash the filter cake with alcohol with a mass concentration of 55 - 60% and 95% until no chloride ions are contained to obtain an extract. Finally, vacuum dry the extract at 55 - 60 °C, pulverize it to obtain the modified Ficus pumila L. seed extract powder.
8. The preparation method of the antibacterial coating according to claim 7, wherein, The specific operation for preparing Ficus pumila L. fruit seeds is as follows: Take mature Ficus pumila L. fruits, remove the fruit stalks and impurities, air-dry them until the moisture content is 8 - 12%, then roll them to separate the pericarp from the seeds, sieve to obtain the seeds, and carry out hot air circulation at 105 - 110 °C for 3 - 5 min and then cool them.
9. The preparation method of the antibacterial coating according to claim 1, characterized in that, In step S5, the mass ratio of the antibacterial material, the filler, and the resin material is 10:12 - 15:45 - 50.
10. An antibacterial coating, characterized in that, The antibacterial coating is prepared by the preparation method according to any one of claims 1 - 9.