An antibacterial stainless steel strip with high surface quality and its preparation method

Abstract

The present invention discloses an antibacterial stainless steel strip with high surface quality and a preparation method thereof, which relates to the technical field of antibacterial stainless steel strips. The preparation method comprises the following steps: smelting ferroalloy raw materials, introducing argon into the ladle after tapping to stir the molten steel to be evenly mixed, and continuously casting the molten steel into a billet; sequentially subjecting the billet to blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment to obtain a stainless steel strip substrate; using the stainless steel strip as a working electrode, a platinum plate as a counter electrode, and a saturated calomel electrode as a reference electrode, depositing silver nanoparticles in an aqueous electrolyte through a three-electrode deposition system, taking out and drying to obtain an electro-deposition modified stainless steel strip; soaking the electro-deposition modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heating and reacting, performing ultrasonic washing with ethanol, drying at room temperature, then soaking in a chitosan-coupled heterojunction solution, maintaining at room temperature, washing with deionized water, and drying in vacuum to obtain the antibacterial stainless steel strip.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial stainless steel strips, and particularly to a high-surface-quality antibacterial stainless steel strip and a preparation method thereof. Background Art

[0002] With the progress of technology and the improvement of people's living standards, antibacterial materials are increasingly widely used in fields such as medical treatment, food processing, and construction. Among them, antibacterial stainless steel strips have attracted much attention due to their excellent mechanical properties and corrosion resistance. However, there are still some significant defects in the existing antibacterial stainless steel strips in practical applications.

[0003] First of all, the antibacterial mechanisms of many antibacterial stainless steel strips are relatively single, mainly relying on the addition of antibacterial agents on the surface or the release of metal ions, such as silver, copper, etc. Although these antibacterial agents are effective, they may be affected by environmental factors such as temperature and humidity in practical applications, resulting in a reduction in their antibacterial effects. In addition, some antibacterial agents may show migration or precipitation phenomena during use, which may potentially harm the environment or human health.

[0004] Secondly, there are also deficiencies in the surface quality of the existing antibacterial stainless steel strips. Traditional preparation methods often make it difficult to achieve high uniformity and delicate surface treatment, resulting in unstable antibacterial properties. In addition, materials with higher surface roughness are more conducive to the attachment and growth of bacteria, further reducing their antibacterial efficiency.

[0005] Therefore, it is urgent to develop a new type of antibacterial stainless steel strip that not only has a diversified antibacterial mechanism but also can improve its antibacterial performance while maintaining high surface quality to meet the growing market demand and application scenarios. Summary of the Invention

[0006] The purpose of the present invention is to provide a high-surface-quality antibacterial stainless steel strip and a preparation method thereof to solve the problems raised in the prior art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A preparation method of a high-surface-quality antibacterial stainless steel strip: including the following steps: S1: Smelt the ferroalloy raw materials, after tapping, introduce argon into the ladle to stir the molten steel to be evenly mixed, and continuously cast the molten steel into a billet;

[0009] S2: Pass the billet through blooming, hot rolling, cold rolling, annealing, solution treatment, and aging treatment in sequence to obtain the stainless steel strip substrate;

[0010] S3: Using a stainless-steel strip as the working electrode, a platinum plate as the counter electrode, and a saturated calomel electrode as the reference electrode, silver nanoparticles are deposited in an aqueous electrolyte through a three-electrode deposition system. After taking it out, it is dried at 40 - 60 °C for 4 - 6 h to obtain an electro-deposition modified stainless-steel strip;

[0011] S4: Immerse the electro-deposition modified stainless-steel strip in a mixed solution of dopamine and octadecylamine, heat it to 37 - 38 °C and react for 6 - 7 h, wash it ultrasonically with ethanol, dry it at room temperature, then immerse it in a chitosan-coupled heterojunction solution of 4 - 5 mg / mL, keep it at room temperature for 2 - 3 h, wash it with deionized water, and vacuum dry it at 40 - 45 °C for 8 - 12 h to obtain an antibacterial stainless-steel strip.

[0012] Furthermore, the ferroalloy raw materials include any one or more of scrap steel, sponge iron, ferrochrome, ferromanganese, and ferrosilicon;

[0013] Furthermore, the elemental composition of the stainless-steel strip substrate by mass percentage includes: C: 0.05 - 0.06, Mn: 4.4 - 4.6, Cr: 14.5 - 15, Ni: 5.5 - 6, Cu: 1.0 - 1.2, Ag: 0.6 - 0.8, Si: 1.2 - 1.4, S ≤ 0.025, P ≤ 0.060, Ce: 0.5 - 0.6, Ti: 0.4 - 0.6, and the rest are Fe and inevitable impurity elements.

[0014] Furthermore, in the step S2, the specific steps of blooming include casting blooming, the casting billet temperature is 1150 - 1160 °C; the hot rolling temperature is 1160 °C - 1180 °C; the annealing temperature is 950 - 960 °C; the solution treatment temperature is 1200 - 1210 °C, the solution treatment time is 2 - 2.5 h, the aging temperature is 620 - 630 °C, and the aging time is 8 - 8.5 h.

[0015] Furthermore, in the preparation process of the electro-deposition modified stainless-steel strip, the aqueous electrolyte is composed of 1 mM silver nitrate solution, 3 - 5 mM citric acid solution, and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process. The parameters of the nucleation process: the nucleation potential is -0.7 - 0.8 V, and the time is 100 s. The parameters of the growth process: the growth potential is -0.1 V, and the time is 600 - 3600 s.

[0016] Furthermore, in the step S4, the mixed solution of dopamine and octadecylamine is composed of 2 - 3 mg / L hydrochloric acid dopamine Tris buffer solution and 50 mM octadecylamine ethanol solution.

[0017] Further, the preparation method of the chitosan-coupled heterojunction includes the following steps: adding chitosan into 0.5-1% v / v acetic acid, heating to 50-52 °C and stirring for 1-1.5 h, cooling to room temperature, adding chitosan nanoparticles, and stirring evenly to obtain mixture A; adding N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysulfosuccinimide into ethanol, and stirring evenly to obtain mixture B; adding bismuth-based metal-organic framework into a mixed solvent of deionized water and glycerol, and stirring evenly to obtain mixture C; adding mixture B into mixture A, stirring for 10-15 min, adding mixture C, stirring at room temperature for 24 h, centrifuging, collecting the solid product, and washing with ethanol and deionized water to obtain the chitosan-coupled heterojunction.

[0018] Further, in the preparation process of the chitosan-coupled heterojunction, the mass ratio of chitosan: chitosan nanoparticles: N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride: N-hydroxysulfosuccinimide: bismuth-based metal-organic framework is 10: 10-20: 1: 1: 1.

[0019] Further, the solvent of the chitosan-coupled heterojunction solution is 0.5% v / v acetic acid.

[0020] Further, the preparation method of the chitosan nanoparticles includes the following steps: adding hematoporphyrin dihydrochloride and triethylamine into dimethyl sulfoxide, stirring at room temperature in the dark for 1-1.5 h, adding 1,3-dicyclohexylcarbodiimide and N-hydroxysuccinimide, keeping warm and stirring for 12-14 h, filtering, collecting the filtrate, adding excessive anhydrous ether, separating the precipitate, and washing with methanol to obtain hematoporphyrin ester; adding chitosan into deionized water, stirring evenly, under ice bath conditions, adding the dimethyl sulfoxide solution of hematoporphyrin ester, adding tetrabutylammonium bromide and 4-(N,N-dimethylamino)pyridine, stirring at room temperature in the dark for 72 h, dialyzing with deionized water for 3 d, and freeze-drying to obtain the crude conjugate; adding the crude conjugate into phosphate buffer solution, ultrasonically treating for 10-15 min, and filtering with a 0.4-0.45 μm filter membrane to obtain chitosan nanoparticles.

[0021] Further, in the preparation process of the hematoporphyrin ester, the mass ratio of hematoporphyrin dihydrochloride: triethylamine: 1,3-dicyclohexylcarbodiimide: N-hydroxysuccinimide is 10: 10: 6.2: 3.5; in the preparation process of the crude conjugate, the mass ratio of chitosan: hematoporphyrin ester: tetrabutylammonium bromide: 4-(N,N-dimethylamino)pyridine is 100: (8-12): 0.5: 0.5.

[0022] Further, the preparation method of the bismuth-based metal-organic framework includes the following steps: adding bismuth nitrate pentahydrate and trimesic acid into methanol, stirring the solution until it becomes clear, heating to 120 - 125 °C and reacting for 24 h, centrifuging, collecting the solid product, washing with methanol, and drying in vacuum at 70 - 75 °C for 12 h to obtain the bismuth-based metal-organic framework; during the preparation process of the bismuth-based metal-organic framework, the mass ratio of bismuth nitrate pentahydrate to trimesic acid is 0.84056:0.2424.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. By adding the complexing agent sodium citrate and adjusting its concentration in the present invention, the complex formed by silver ions and citric acid will accelerate the electrodeposition rate, improve the current efficiency, and reduce the activation overpotential, thereby improving the electrodeposition process of silver nanoparticles; adding the complexing agent sodium citrate to the electrolyte makes (CitAg) 2− in Cit 3− compete with the reduction process of Ag + to a certain extent, inhibiting the conversion of Ag + to Ag + . The addition of excessive CitNa makes silver ions mainly exist in the form of Ag 0 (Cit m ) 3− ) n , resulting in partial coating of Ag + ions by Cit 3− ions, thus promoting the regular deposition of Ag nanoparticles on the positive electrode. Utilizing the release of Ag + ions from the surface coating of Ag nanoparticles into the surrounding aqueous medium to promote the generation of reactive oxygen species or directly damage the cell membrane. At the same time, nano-Ag particles can directly adsorb on the cell membrane of bacteria, affecting membrane permeability and normal respiration. The coating formed by dopamine-octadecylamine on the surface of silver nanoparticles has a synergistic effect with the silver nanoparticles. On the one hand, the presence of silver nanoparticles helps to induce the adsorption of dopamine-octadecylamine complexes on the surface; on the other hand, the presence of the dopamine-octadecylamine coating helps to effectively control the release of Ag + , greatly improving the service life of the antibacterial stainless steel strip.

[0025] 2. The present invention activates hematoporphyrin and couples it to chitosan, and prepares antibacterial chitosan nanoparticles based on photodynamic action through ultrasonic treatment and filtration. On this basis, a chitosan-coupled heterojunction based on the coupling of chitosan and bismuth-based metal-organic frameworks is synthesized. On the one hand, the reactive oxygen species generated by hematoporphyrin under light can change the structure of the nanoparticles by oxidizing the chitosan backbone, thereby significantly improving the photodynamic antibacterial activity of hematoporphyrin; on the other hand, the chitosan-coupled heterojunction has a higher electron-hole separation efficiency, improves the light absorption rate, especially for visible light, prolongs the electron-hole lifetime, reduces the band gap, and more electrons can be excited into the conduction band and participate in the photocatalytic reaction, thereby greatly improving the photocatalytic performance. The chitosan-coupled heterojunction exhibits better photocatalytic antibacterial activity against Escherichia coli and Staphylococcus aureus than the pure catalyst under visible light irradiation. Silver nanoparticles and the chitosan-coupled heterojunction provide a dual antibacterial mechanism for the antibacterial stainless steel strip, greatly expanding the application scenarios of the antibacterial stainless steel strip and increasing the service life of the antibacterial stainless steel strip. Detailed implementation manners

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] In the following embodiments, the preparation method of chitosan nanoparticles includes the following steps: Add 10 mg of hematoporphyrin dihydrochloride and 10 mg of triethylamine to 20 mL of dimethyl sulfoxide, stir at room temperature in the dark for 1 h, add 6.2 mg of 1,3-dicyclohexylcarbodiimide and 3.5 mg of N-hydroxysuccinimide, stir at a constant temperature for 12 h, filter, collect the filtrate, add an excess of anhydrous ether, separate the precipitate, and wash with methanol to obtain hematoporphyrin ester; Add 100 mg of chitosan to deionized water, stir evenly, under ice bath conditions, add a dimethyl sulfoxide solution containing 8 mg of hematoporphyrin ester, add 0.5 mg of tetrabutylammonium bromide and 0.5 mg of 4-(N,N-dimethylamino)pyridine, stir at room temperature in the dark for 72 h, dialyze with deionized water for 3 d, and freeze-dry to obtain a crude conjugate; Add the crude conjugate to phosphate buffer solution, perform ultrasonic treatment for 10 min, and filter with a 0.45 μm filter membrane to obtain chitosan nanoparticles.

[0028] In the following examples, the preparation method of the bismuth-based metal-organic framework includes the following steps: Add 0.84056 g of bismuth nitrate pentahydrate and 0.2424 g of trimesic acid to 40 mL of methanol, stir the solution until it is clear, heat it to 120 °C and react for 24 h, centrifuge, collect the solid product, wash it with methanol, and dry it under vacuum at 70 °C for 12 h to obtain the bismuth-based metal-organic framework.

[0029] Example 1: A preparation method of an antibacterial stainless steel strip with high surface quality: includes the following steps: S1: Smelt the ferroalloy raw materials. After tapping, introduce argon into the ladle to stir the molten steel evenly, and continuously cast the molten steel into a billet;

[0030] S2: Pass the billet through blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain a stainless steel strip substrate;

[0031] S3: Use the stainless steel strip as the working electrode, the platinum plate as the counter electrode, and the saturated calomel electrode as the reference electrode. Deposit silver nanoparticles in the aqueous electrolyte through a three-electrode deposition system, take it out, and dry it at 40 - 60 °C for 4 - 6 h to obtain an electro-deposition modified stainless steel strip; Among them, in the step S2, the specific steps of blooming include casting blooming, the temperature of the billet is 1150 °C; the hot rolling temperature is 1160 °C; the annealing temperature is 950 °C; the solution treatment temperature is 1200 °C, the solution treatment time is 2 h, the aging temperature is 620 °C, and the aging time is 8 h; the aqueous electrolyte is composed of 1 mM silver nitrate solution, 3 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process. The parameters of the nucleation process: the nucleation potential is -0.7 V, and the time is 100 s. The parameters of the growth process: the growth potential is -0.1 V, and the time is 3600 s;

[0032] S4: Add 1 g of chitosan to 100 mL of 0.8% v / v acetic acid, heat it to 50 °C and stir for 1 - 1.5 h, cool it to room temperature, add 1 g of chitosan nanoparticles, and stir evenly to obtain mixture A; Add 0.1 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysulfosuccinimide to ethanol, and stir evenly to obtain mixture B; Add 0.1 g of the bismuth-based metal-organic framework to a mixed solvent of 20 mL of deionized water and 10 mL of glycerol, and stir evenly to obtain mixture C; Add mixture B to mixture A, stir for 10 min, add mixture C, and stir at room temperature for 24 h, centrifuge, collect the solid product, and wash it with ethanol and deionized water to obtain a chitosan-coupled heterojunction;

[0033] S5: Immerse the electroplated modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heat it to 37 °C and react for 6 h, wash it ultrasonically with ethanol, dry it at room temperature, then immerse it in a 4 mg / mL chitosan-coupled heterojunction solution, keep it at room temperature for 2 h, wash it with deionized water, and dry it under vacuum at 40 °C for 8 h to obtain the antibacterial stainless steel strip.

[0034] Example 2: A method for preparing an antibacterial stainless steel strip with high surface quality, comprising the following steps: S1: Smelt the ferroalloy raw materials, introduce argon into the ladle after tapping to stir the molten steel evenly, and continuously cast the molten steel into a billet;

[0035] S2: Pass the billet through blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain the stainless steel strip substrate;

[0036] S3: Use the stainless steel strip as the working electrode, the platinum plate as the counter electrode, and the saturated calomel electrode as the reference electrode. Deposit silver nanoparticles in the aqueous electrolyte through a three-electrode deposition system, take it out, and dry it at 40 - 60 °C for 4 - 6 h to obtain the electroplated modified stainless steel strip; wherein, in the step S2, the specific steps of blooming include casting blooming, and the billet temperature is 1150 °C; the hot rolling temperature is 1160 °C; the annealing temperature is 950 °C; the solution treatment temperature is 1200 °C, and the solution treatment time is 2 h, the aging temperature is 620 °C, and the aging time is 8 h; the aqueous electrolyte is composed of 1 mM silver nitrate solution, 3 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process. The parameters of the nucleation process: the nucleation potential is -0.7 V, and the time is 100 s. The parameters of the growth process: the growth potential is -0.1 V, and the time is 3600 s;

[0037] S4: Add 1 g of chitosan to 100 mL of 0.8% v / v acetic acid, heat it to 50 °C and stir for 1 - 1.5 h, cool it to room temperature, add 2 g of chitosan nanoparticles, and stir evenly to obtain mixture A; add 0.1 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysulfosuccinimide to ethanol, and stir evenly to obtain mixture B; add 0.1 g of bismuth-based metal-organic framework to a mixed solvent of 20 mL of deionized water and 10 mL of glycerol, and stir evenly to obtain mixture C; add mixture B to mixture A, stir for 10 min, add mixture C, stir at room temperature for 24 h, centrifuge, collect the solid product, and wash it with ethanol and deionized water to obtain the chitosan-coupled heterojunction;

[0038] S5: Immerse the electroplated modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heat to 37 °C and react for 6 h, perform ultrasonic washing with ethanol, dry at room temperature, then immerse in a 4 mg / mL chitosan-coupled heterojunction solution, keep at room temperature for 2 h, wash with deionized water, and dry in vacuum at 40 °C for 8 h to obtain the antibacterial stainless steel strip.

[0039] Example 3: A preparation method of an antibacterial stainless steel strip with high surface quality: The method comprises the following steps: S1: Smelt the ferroalloy raw materials, introduce argon into the ladle after tapping to stir the molten steel evenly, and continuously cast the molten steel into slabs;

[0040] S2: Pass the slab through blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain the stainless steel strip substrate;

[0041] S3: Use the stainless steel strip as the working electrode, the platinum plate as the counter electrode, and the saturated calomel electrode as the reference electrode, deposit silver nanoparticles in the aqueous electrolyte through a three-electrode deposition system, take out, and dry at 40 - 60 °C for 4 - 6 h to obtain the electroplated modified stainless steel strip; wherein, in the step S2, the specific steps of blooming include casting blooming, and the temperature of the slab is 1150 °C; the hot rolling temperature is 1160 °C; the annealing temperature is 950 °C; the solution treatment temperature is 1200 °C, and the solution treatment time is 2 h, the aging temperature is 620 °C, and the aging time is 8 h; the aqueous electrolyte is composed of 1 mM silver nitrate solution, 3 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process, the parameters of the nucleation process: the nucleation potential is -0.7 V, and the time is 100 s, the parameters of the growth process: the growth potential is -0.1 V, and the time is 3600 s;

[0042] S4: Add 1 g of chitosan to 100 mL of 0.8% v / v acetic acid, heat to 50 °C and stir for 1 - 1.5 h, cool to room temperature, add 2 g of chitosan nanoparticles, and stir evenly to obtain mixture A; add 0.1 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysulfosuccinimide to ethanol, and stir evenly to obtain mixture B; add 0.1 g of bismuth-based metal-organic framework to a mixed solvent of 20 mL of deionized water and 10 mL of glycerol, and stir evenly to obtain mixture C; add mixture B to mixture A, stir for 10 min, add mixture C, stir at room temperature for 24 h, centrifuge, collect the solid product, and wash with ethanol and deionized water to obtain the chitosan-coupled heterojunction;

[0043] S5: Immerse the electroplated modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heat it to 37 °C and react for 6 h, wash it ultrasonically with ethanol, dry it at room temperature, then immerse it in a 5 mg / mL chitosan-coupled heterojunction solution, keep it at room temperature for 2 h, wash it with deionized water, and dry it in vacuum at 40 °C for 8 h to obtain the antibacterial stainless steel strip.

[0044] Comparative Example 1: A method for preparing an antibacterial stainless steel strip with high surface quality, comprising the following steps: S1: Smelt the ferroalloy raw materials, introduce argon into the ladle after tapping to stir the molten steel evenly, and continuously cast the molten steel into a billet;

[0045] S2: Subject the billet to blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain the stainless steel strip substrate;

[0046] S3: Use the stainless steel strip as the working electrode, the platinum plate as the counter electrode, and the saturated calomel electrode as the reference electrode, deposit silver nanoparticles in the aqueous electrolyte through a three-electrode deposition system, take it out, and dry it at 40 - 60 °C for 4 - 6 h to obtain the electroplated modified stainless steel strip; wherein, in the step S2, the specific steps of blooming include casting blooming, and the temperature of the billet is 1150 °C; the hot rolling temperature is 1160 °C; the annealing temperature is 950 °C; the solution treatment temperature is 1200 °C, and the solution treatment time is 2 h, the aging temperature is 620 °C, and the aging time is 8 h; the aqueous electrolyte is composed of 1 mM silver nitrate solution, 0.5 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process, the parameters of the nucleation process: the nucleation potential is -0.7 V, and the time is 100 s, the parameters of the growth process: the growth potential is -0.1 V, and the time is 3600 s;

[0047] S4: Add 1 g of chitosan to 100 mL of 0.8% v / v acetic acid, heat it to 50 °C and stir for 1 - 1.5 h, cool it to room temperature, add 1 g of chitosan nanoparticles, and stir evenly to obtain mixture A; add 0.1 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysulfosuccinimide to ethanol, and stir evenly to obtain mixture B; add 0.1 g of bismuth-based metal-organic framework to a mixed solvent of 20 mL of deionized water and 10 mL of glycerol, and stir evenly to obtain mixture C; add mixture B to mixture A, stir for 10 min, add mixture C, stir at room temperature for 24 h, centrifuge, collect the solid product, and wash it with ethanol and deionized water to obtain chitosan-coupled heterojunction;

[0048] S5: Immerse the electroplated modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heat it to 37 °C and react for 6 h, wash it ultrasonically with ethanol, dry it at room temperature, then immerse it in a 4 mg / mL chitosan-coupled heterojunction solution, keep it at room temperature for 2 h, wash it with deionized water, and dry it under vacuum at 40 °C for 8 h to obtain an antibacterial stainless steel strip.

[0049] Comparative Example 2: A preparation method of an antibacterial stainless steel strip with high surface quality, comprising the following steps: S1: Smelt the ferroalloy raw materials, introduce argon into the ladle after tapping to stir the molten steel evenly, and continuously cast the molten steel into a billet;

[0050] S2: Subject the billet to blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain a stainless steel strip substrate;

[0051] S3: Use the stainless steel strip as the working electrode, the platinum plate as the counter electrode, and the saturated calomel electrode as the reference electrode. Deposit silver nanoparticles in the aqueous electrolyte through a three-electrode deposition system, take it out, and dry it at 40-60 °C for 4-6 h to obtain an electroplated modified stainless steel strip; wherein, in the step S2, the specific steps of blooming include casting blooming, and the temperature of the billet is 1150 °C; the hot rolling temperature is 1160 °C; the annealing temperature is 950 °C; the solution treatment temperature is 1200 °C, and the solution treatment time is 2 h, the aging temperature is 620 °C, and the aging time is 8 h; the aqueous electrolyte is composed of 0.5 mM silver nitrate solution, 3 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process. The parameters of the nucleation process: the nucleation potential is -0.7 V, and the time is 100 s. The parameters of the growth process: the growth potential is -0.1 V, and the time is 3600 s;

[0052] S4: Add 1 g of chitosan to 100 mL of 0.8% v / v acetic acid, heat it to 50 °C and stir for 1-1.5 h, cool it to room temperature, add 1 g of chitosan nanoparticles, and stir evenly to obtain mixture A; add 0.1 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysulfosuccinimide to ethanol, and stir evenly to obtain mixture B; add 0.1 g of bismuth-based metal-organic framework to a mixed solvent of 20 mL of deionized water and 10 mL of glycerol, and stir evenly to obtain mixture C; add mixture B to mixture A, stir for 10 min, add mixture C, stir at room temperature for 24 h, centrifuge, collect the solid product, and wash it with ethanol and deionized water to obtain chitosan-coupled heterojunction;

[0053] S5: Immerse the electroplated modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heat to 37 °C and react for 6 h, wash it ultrasonically with ethanol, dry it at room temperature, then immerse it in a 4 mg / mL chitosan-coupled heterojunction solution, keep it at room temperature for 2 h, wash it with deionized water, and vacuum dry it at 40 °C for 8 h to obtain an antibacterial stainless steel strip.

[0054] Comparative Example 3: A preparation method of an antibacterial stainless steel strip with high surface quality, comprising the following steps: S1: Smelt the ferroalloy raw materials, introduce argon into the ladle after tapping to stir the molten steel evenly, and continuously cast the molten steel into a billet;

[0055] S2: Pass the billet through blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain a stainless steel strip substrate;

[0056] S3: Use the stainless steel strip as the working electrode, the platinum plate as the counter electrode, and the saturated calomel electrode as the reference electrode. Deposit silver nanoparticles in the aqueous electrolyte through a three-electrode deposition system, take it out, and dry it at 40-60 °C for 4-6 h to obtain an electroplated modified stainless steel strip; wherein, in the step S2, the specific steps of blooming include casting blooming, and the temperature of the billet is 1150 °C; the hot rolling temperature is 1160 °C; the annealing temperature is 950 °C; the solution treatment temperature is 1200 °C, and the solution treatment time is 2 h, the aging temperature is 620 °C, and the aging time is 8 h; the aqueous electrolyte is composed of 1 mM silver nitrate solution, 3 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process. The parameters of the nucleation process: the nucleation potential is -0.7 V, and the time is 100 s. The parameters of the growth process: the growth potential is -0.1 V, and the time is 3600 s;

[0057] S4: Add 1 g of chitosan and 1 g of chitosan nanoparticles to 100 mL of 0.8% v / v acetic acid, heat to 50 °C and stir for 1-1.5 h, cool to room temperature to obtain mixture A; add 0.1 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysulfosuccinimide to ethanol, stir evenly to obtain mixture B; add 0.1 g of bismuth-based metal-organic framework to a mixed solvent of 20 mL of deionized water and 10 mL of glycerol, stir evenly to obtain mixture C; add mixture B to mixture A, stir for 10 min, add mixture C, stir at room temperature for 24 h, centrifuge, collect the solid product, and wash it with ethanol and deionized water to obtain chitosan-coupled heterojunction;

[0058] S5: Immerse the electroplated modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heat it to 37 °C and react for 6 h, wash it ultrasonically with ethanol, dry it at room temperature, then immerse it in a 4 mg / mL chitosan-coupled heterojunction solution, keep it at room temperature for 2 h, wash it with deionized water, and dry it in vacuum at 40 °C for 8 h to obtain the antibacterial stainless steel strip.

[0059] Comparative Example 4: A preparation method of an antibacterial stainless steel strip with high surface quality, comprising the following steps: S1: Smelt the ferroalloy raw materials, introduce argon into the ladle after tapping to stir the molten steel evenly, and continuously cast the molten steel into a billet.

[0060] S2: Subject the billet to blooming, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain the stainless steel strip substrate.

[0061] S3: Use the stainless steel strip as the working electrode, the platinum plate as the counter electrode, and the saturated calomel electrode as the reference electrode, deposit silver nanoparticles in the aqueous electrolyte through a three-electrode deposition system, take it out, and dry it at 40 - 60 °C for 4 - 6 h to obtain the electroplated modified stainless steel strip; wherein, in the step S2, the specific steps of blooming include casting blooming, and the temperature of the billet is 1150 °C; the hot rolling temperature is 1160 °C; the annealing temperature is 950 °C; the solution treatment temperature is 1200 °C, and the solution treatment time is 2 h, the aging temperature is 620 °C, and the aging time is 8 h; the aqueous electrolyte is composed of 1 mM silver nitrate solution, 3 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process, the parameters of the nucleation process: the nucleation potential is -0.7 V, and the time is 100 s, the parameters of the growth process: the growth potential is -0.1 V, and the time is 3600 s.

[0062] S4: Add 1 g of chitosan to 100 mL of 0.8% v / v acetic acid, heat it to 50 °C and stir for 1 - 1.5 h, cool it to room temperature, add 3 g of chitosan nanoparticles, and stir evenly to obtain mixture A; add 0.1 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysulfosuccinimide to ethanol, and stir evenly to obtain mixture B; add 0.1 g of bismuth-based metal-organic framework to a mixed solvent of 20 mL of deionized water and 10 mL of glycerol, and stir evenly to obtain mixture C; add mixture B to mixture A, stir for 10 min, add mixture C, stir at room temperature for 24 h, centrifuge, collect the solid product, and wash it with ethanol and deionized water to obtain chitosan-coupled heterojunction.

[0063] S5: Immerse the electroplated modified stainless steel strip in a mixed solution of dopamine and octadecylamine, heat it to 37 °C and react for 6 h, wash it ultrasonically with ethanol, dry it at room temperature, then immerse it in a 4 mg / mL chitosan-coupled heterojunction solution, keep it at room temperature for 2 h, wash it with deionized water, and dry it in vacuum at 40 °C for 8 h to obtain an antibacterial stainless steel strip.

[0064] Experiment: Antibacterial experiment: Activate and rejuvenate all strains (Staphylococcus aureus, Escherichia coli), and further dilute the rejuvenated strains to about 10 5 colony forming units (CFU.mL -1 ) for antibacterial determination; Place 10 mm × 10 mm sample fragments on the agar medium and incubate them simultaneously under light and dark conditions at 37 °C (illuminance ≥ 20,000 Lx, using a common LED light source), incubate for 24 h, and measure the diameter of the inhibition zone in millimeters.

[0065] The experimental data are shown in Table 1 below.

[0066] Table 1 Antibacterial performance data table of antibacterial stainless steel strip

[0067]

[0068] Conclusion: The antibacterial stainless steel strip prepared by the present invention has excellent antibacterial performance.

[0069] In Comparative Example 1, the concentration of sodium citrate added was too low, and in Comparative Example 2, the concentration of silver nitrate was too low; due to the low concentrations of sodium citrate and silver nitrate, the Ag + concentration on the particle surface was low, forming a so-called depletion layer, thus inhibiting the growth of Ag nanoparticles. In the preparation of chitosan-coupled heterojunction in Comparative Example 3, chitosan and chitosan nanoparticles were added simultaneously, resulting in the destruction of the structure of some chitosan nanoparticles; in the preparation of chitosan-coupled heterojunction in Comparative Example 4, the amount of chitosan nanoparticles added was too much, resulting in an imperfect structure of the chitosan-coupled heterojunction.

[0070] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A method for preparing an antibacterial stainless steel belt with high surface quality, characterized in that: The following steps are involved: S1: smelting the ferroalloy raw materials, introducing argon into the ladle after steel is tapped, stirring the molten steel to mix evenly, and continuously casting the molten steel into billets; S2: subjecting the ingot to blanking, hot rolling, cold rolling, annealing, solution treatment and aging treatment in sequence to obtain a stainless steel strip substrate; S3: Using a stainless steel strip as a working electrode, a platinum plate as a counter electrode, and a saturated calomel electrode as a reference electrode, silver nanoparticles are deposited in an aqueous electrolyte through a three-electrode deposition system, and then taken out and dried at 40-60°C for 4-6h to obtain an electrodeposited modified stainless steel strip; S4: soaking the electrodeposited modified stainless steel strip in a mixed solution of dopamine-octadecylamine, heating to 37-38°C for reaction for 6-7h, ultrasonically washing with ethanol, drying at room temperature, and then soaking in a 4-5mg / mL chitosan coupled heterojunction solution, keeping at room temperature for 2-3h, washing with deionized water, and vacuum drying at 40-45°C for 8-12h to obtain an antibacterial stainless steel strip; The preparation method of the chitosan coupled heterojunction comprises the following steps: adding chitosan to 0.5-1% v / v acetic acid, heating to 50-52° C. and stirring for 1-1.5 hours, cooling to room temperature, adding chitosan nanoparticles, stirring evenly, and obtaining a mixture A; adding N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysulfosuccinimide to ethanol, stirring evenly, and obtaining a mixture B; adding a bismuth-based metal organic framework to a mixed solvent of deionized water and glycerol, stirring evenly, and obtaining a mixture C; adding the mixture B to the mixture A, stirring for 10-15 minutes, adding the mixture C, stirring at room temperature for 24 hours, centrifuging, collecting the solid product, and washing with ethanol and deionized water to obtain a chitosan coupled heterojunction; The preparation method of chitosan nanoparticles comprises the following steps: adding hematoporphyrin dihydrochloride and triethylamine to dimethyl sulfoxide, stirring at room temperature in the dark for 1-1.5 hours, adding 1,3-dicyclohexylcarbodiimide and N-hydroxysuccinimide, stirring at the same temperature for 12-14 hours, filtering, collecting the filtrate, adding excess anhydrous ether, separating the precipitate, washing with methanol, and obtaining hematoporphyrin ester; adding chitosan to deionized water, stirring evenly, adding a dimethyl sulfoxide solution of hematoporphyrin ester under ice bath conditions, adding tetrabutylammonium bromide and 4-(N,N-dimethylamino)pyridine, stirring at room temperature in the dark for 72 hours, dialyzing with deionized water for 3 days, and freeze-drying to obtain a crude conjugate; adding the crude conjugate to a phosphate buffer, ultrasonically treating for 10-15 minutes, filtering with a 0.4-0.45 μm filter membrane, and obtaining chitosan nanoparticles; The preparation method of the bismuth-based metal organic framework comprises the following steps: adding bismuth nitrate pentahydrate and trimesic acid into methanol, stirring the solution until it is clear, heating it to 120-125° C. for reaction for 24 hours, centrifuging, collecting the solid product, washing it with methanol, and vacuum drying it at 70-75° C. for 12 hours to obtain the bismuth-based metal organic framework; during the preparation process of the bismuth-based metal organic framework, the mass ratio of bismuth nitrate pentahydrate: trimesic acid is 0.84056:0.2424.

2. The method for preparing an antibacterial stainless steel strip with high surface quality according to claim 1, characterized in that: In step S2, the specific steps of blanking include casting blanking, the blanking temperature is 1150-1160℃; the hot rolling temperature is 1160℃-1180℃; the annealing temperature is 950-960℃; the solid solution temperature is 1200-1210℃, the solid solution time is 2-2.5h, the aging temperature is 620-630℃, and the aging time is 8-8.5h.

3. The method for preparing an antibacterial stainless steel strip with high surface quality according to claim 1, characterized in that: During the preparation of the electrodeposited modified stainless steel strip, the aqueous electrolyte consists of 1 mM silver nitrate solution, 3-5 mM citric acid solution and 0.1 mM potassium nitrate solution; the silver nanoparticle deposition process includes a nucleation process and a growth process. The nucleation process parameters are: the nucleation potential is -0.7-0.8 V, the time is 100 s, and the growth process parameters are: the growth potential is -0.1 V, and the time is 600-3600 s.

4. The method for preparing an antibacterial stainless steel strip with high surface quality according to claim 1, characterized in that: In step S4, the mixed solution of dopamine-octadecylamine is composed of 2-3 mg / L dopamine hydrochloride Tris buffer solution and 50 mM octadecylamine ethanol solution.

5. The method for preparing an antibacterial stainless steel strip with high surface quality according to claim 1, characterized in that: In the preparation process of chitosan coupled heterojunction, the mass ratio of chitosan: chitosan nanoparticles: N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride: N-hydroxysulfosuccinimide: bismuth-based metal organic framework is 10:10-20:1:1:

1.

6. The method for preparing an antibacterial stainless steel strip with high surface quality according to claim 1, characterized in that: In the preparation process of hematoporphyrin ester, the mass ratio of hematoporphyrin dihydrochloride: triethylamine: 1,3-dicyclohexylcarbodiimide: N-hydroxysuccinimide is 10:10:6.2:3.5; in the preparation process of the crude conjugate, the mass ratio of chitosan: hematoporphyrin ester: tetrabutylammonium bromide: 4-(N,N-dimethylamino)pyridine is 100:(8-12):0.5:0.

5.

7. The antibacterial stainless steel strip prepared according to the method for preparing an antibacterial stainless steel strip with high surface quality according to any one of claims 1 to 6.

Images