Preparation method and application of modified nano cuprous oxide

Abstract

The invention belongs to the technical field of synthesis of inorganic nano materials, and relates to a preparation method and application of nano cuprous oxide, and the preparation method comprises the following steps: carrying out a synthesis reaction on a copper source, a reducing agent and a pH regulator in water; stirring and reacting the obtained solid-phase product and a silane modifier in an alcohol-water solution, and separating and purifying to obtain nano cuprous oxide; wherein the silane modifying agent is selected from one of gamma-methacryloxy propyl methyl dimethoxy silane, gamma-glycidyl ether oxypropyl trimethoxy silane, gamma-aminopropyl triethoxy silane and gamma-methacryloxy propyl trimethoxy silane, and the silane modifying agent is selected from one of gamma-methacryloxy propyl methyl dimethoxy silane, gamma-glycidyl ether oxypropyl trimethoxy silane, gamma-aminopropyl triethoxy silane and gamma-methacryloxy propyl trimethoxy silane. Compared with the prior art, the modified nano cuprous oxide powder is prepared on a large scale by adopting a liquid phase reduction method, a surfactant does not need to be added, the preparation process is simple, the reaction filtrate can be recycled, high-pressure and high-temperature operation risks are avoided, the particle size distribution of the product is 20-50nm, industrial amplification is easy, and the industrial recovery rate exceeds 95%; the chemical use effect of cuprous oxide is not influenced.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic nanomaterial synthesis, and relates to a preparation method and application of modified nano cuprous oxide. Background Art

[0002] Copper is a common metallic element in our daily lives, with widespread applications in electronics, electrical engineering, construction, transportation, and machinery manufacturing. Copper compounds, such as copper oxide, cuprous oxide, and cuprous iodide, as well as other inorganic materials, hold significant market potential in the processing and production of functional materials.

[0003] Cuprous oxide is a common copper-containing oxide with a P-type semiconductor structure. It is low-cost, readily available, and boasts excellent antimicrobial and photocatalytic properties, making it widely used in industries such as antimicrobial materials, photovoltaic cells, catalysts, and antifouling coatings. In the coatings industry, for example, cuprous oxide is the primary antimicrobial agent required for antifouling coatings on ocean-going vessels. Cuprous oxide slowly releases copper ions in seawater, reducing microbial adhesion on the vessel's surface and improving its antifouling capabilities and energy efficiency. In the field of antimicrobial textiles, as public awareness of safety increases, people are increasingly focusing on additives for antimicrobial fabrics. Antimicrobial ingredients such as copper and zinc are gradually replacing more toxic silver to reduce the biotoxicity of processed antimicrobial fibers. Ultrafine nanocuprous oxide powder exhibits a nanoscale effect, with a particle size distribution between 20 and 50 nm exhibiting strong chemical activity, making it a key focus of current industrial applications.

[0004] However, in terms of storage conditions, nano-cuprous oxide is highly reactive and will deteriorate into cupric oxide within one month when exposed to air, which seriously restricts the transportation and application potential of nano-cuprous oxide powder. On the other hand, the nanoparticles themselves aggregate due to van der Waals forces, which reduces the activity and dispersibility of cuprous oxide, hindering its application in coatings, fibers and other fields.

[0005] Prior art CN114959937A discloses a high-content nano-cuprous oxide antibacterial nylon yarn, and the raw materials for preparing the yarn include polyamide (PA-66), cuprous oxide powder, and a dispersant. This technical solution, by optimizing the particle size of cuprous oxide and the type of dispersant, enables nano-cuprous oxide to smoothly follow the polyamide in ejecting from the spinneret, thereby reducing the occurrence of melt nozzle blockage, and by optimizing the weight ratio of cuprous oxide, dispersant, and polyamide, enables nano-cuprous oxide to be uniformly dispersed in the polyamide melt, thereby increasing the content of nano-cuprous oxide in the polyamide, and achieving an ultra-high content of 6500ppm, thereby improving the antibacterial performance of the polyamide fiber. However, there is still a problem of poor antibacterial performance. When the cuprous oxide powder content is about 1%, the inhibition rate against Escherichia coli is only 96.7%, the inhibition rate against Staphylococcus aureus is only 97.8%, and the inhibition rate against Staphylococcus aureus is only 97.9%. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing and applying modified nano-cuprous oxide, which is used to address the problem of poor dispersibility of nano-cuprous oxide in polyamide and the resulting poor antibacterial properties of polyamide materials doped with nano-cuprous oxide. The present invention achieves graft modification of nano-cuprous oxide by stirring and reacting a silane modifier such as γ-methacryloxypropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, or γ-methacryloxypropyltrimethoxysilane with nano-cuprous oxide, thereby improving the dispersibility of nano-cuprous oxide in polyamide materials and effectively exerting its antibacterial properties. The present invention has the advantages of large-scale preparation, high purity, good dispersibility, easy operation, no generation of toxic substances, and high raw material utilization.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] The first aspect of the present invention provides a method for preparing modified nano-cuprous oxide, comprising: reacting a copper source, a reducing agent, and a pH regulator in water; reacting the obtained solid phase product with a silane modifier in an alcohol aqueous solution with stirring, and separating and purifying to obtain the modified nano-cuprous oxide;

[0009] The silane modifier is selected from one of γ-methacryloxypropylmethyldimethoxysilane, N-aminoethyl-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-methacryloxypropyltrimethoxysilane. In some specific embodiments, the mass ratio of the copper source to the silane modifier is 50-150:1-30.

[0010] In some specific embodiments, the copper source is selected from at least one of copper acetate monohydrate, copper chloride dihydrate, copper nitrate trihydrate, or copper sulfate pentahydrate.

[0011] In some specific embodiments, the reducing agent is selected from one of L-ascorbic acid, hydrazine hydrate, sodium borohydride or sodium thiosulfate.

[0012] In some specific embodiments, the pH adjuster is selected from one of sodium hydroxide, potassium hydroxide, urea or ammonia water.

[0013] In some specific embodiments, the mass ratio of the copper source, the reducing agent, and the pH adjuster is 5-15:3-8:3-8.

[0014] In some specific embodiments, in the synthesis reaction, the reaction temperature is room temperature and the reaction time is 15 to 60 minutes.

[0015] In some specific embodiments, during the stirring reaction, the reaction temperature is room temperature, the reaction time is 4 to 48 hours, and the stirring time affects the modification effect. The alcohol aqueous solution is an aqueous solution of 30 to 70 wt% methanol or ethanol.

[0016] In some specific embodiments, in the synthesis reaction, the initial concentration of copper ions should be controlled at 0.05 to 1 mol / L; in the stirring reaction, the mass of the alcohol-water solution should be no less than 10 times the mass of the copper source.

[0017] In some specific embodiments, the preparation method of modified nano-cuprous oxide, such as Figure 1 As shown, the following steps are included:

[0018] 1) A copper source, a reducing agent, and a pH adjuster are reacted in water to obtain product A;

[0019] 2) Filtering the product A and washing with water to obtain the product B; the resulting filtrate and washing liquid X (water) can be recovered and recycled as the reaction solvent for the synthesis reaction; if a white precipitate appears in the filtrate after multiple cycles, it is treated as waste liquid and is not used further;

[0020] 3) reacting the product B with a silane modifier in an alcohol-water solution with stirring to obtain a product C; the obtained product C is centrifugally dried to obtain a final product, nano-cuprous oxide; the filtrate (alcohol-water solution) after centrifugation is recovered and recycled as a reaction solvent for the stirring reaction; if a white precipitate appears in the filtrate after multiple cycles, it is treated as waste liquid and is not further used.

[0021] A second aspect of the present invention provides an application of modified nano-cuprous oxide prepared by the method described above, comprising using the nano-cuprous oxide to prepare antibacterial fibers or antifouling coatings (such as anti-algae coatings).

[0022] In some specific embodiments, the antibacterial fiber is an antibacterial nylon fiber, and the preparation method of the antibacterial nylon fiber comprises: blending and extruding nano cuprous oxide and nylon material;

[0023] The extrusion conditions are selected from one of the following conditions:

[0024] (1) Using a single screw extruder with an aspect ratio of >40:1, a screw speed of 25-40 r / min, a temperature of 250-280°C in zone 1, a temperature of 265-280°C in zones 2 to 4, and a temperature of 273-280°C in zone 5;

[0025] (2) A twin-screw extruder is used with an aspect ratio of >30:1, a screw speed of 25-40 r / min, a temperature in zone 1 of 250-280°C, a temperature in zones 2 to 4 of 265-280°C, and a temperature in zone 5 of 273-280°C.

[0026] Compared with the prior art, the present invention has the following characteristics:

[0027] The present invention prepares nano-cuprous oxide powder by modifying with a silane modifier such as γ-methacryloxypropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, or γ-methacryloxypropyltrimethoxysilane. The powder has a particle size distribution of 20 to 50 nm and a uniform particle distribution. The powder can be directly applied to polymers and coatings. Compared with unmodified nano-powders, the powder has better material dispersibility and oxidation resistance, which helps improve the material's stability and extend its service life. The powder is suitable for the preparation of antifouling coatings and antibacterial fibers.

[0028] Based on the good dispersibility of nano-cuprous oxide powder in polymer materials, especially nylon materials, the present invention effectively solves the problem of poor melt fluidity and difficult processing caused by nano-cuprous oxide powder agglomeration. Experiments have shown that the nano-cuprous oxide powder of the present invention can achieve a single continuous preparation of 50 kg of modified nylon material at a doping level of 0.5 wt%, providing a solid foundation for the large-scale industrial production of such materials.

[0029] The present invention adopts a liquid phase reduction method to prepare modified nano cuprous oxide powder, which has a simple process, can complete the reaction at room temperature and pressure, does not require heating treatment, does not have the risk of high-pressure and high-temperature operation, and is easy to scale up industrially; compared with thermal decomposition method and gas / solid phase synthesis method, the present invention has low energy demand, does not need to provide a reducing atmosphere, has a relatively simple production process, has a fast reaction speed, and has relatively low safety requirements; at the same time, compared with the conventional liquid phase reduction method, the silane reagent used in the present invention has no biological toxicity, has a high adhesion rate on nano cuprous oxide, and the hydrolysis byproduct is an organic silicon glass powder, which is also non-toxic, and does not need to add a surfactant (such as hexadecyl ammonium bromide, CTAB) to reduce Or control the powder particle size, effectively avoid the generation of organic waste liquid, avoid causing serious pollution to the environment, the reaction filtrate of the synthesis reaction and the stirring reaction can be recycled, the raw material cost is significantly reduced, and the water resource utilization rate is significantly improved (about 72g product / 1 liter of water), which is in line with the concept of modern green development; in summary, the present invention is based on the liquid phase reduction method, is simple to operate, green and environmentally friendly, and low in cost, can prepare nano cuprous oxide in large quantities and without pollution, fully utilizes the reaction solution, improves the raw material utilization rate, fully implements the concept of green chemistry, and also effectively improves the dispersibility and antioxidant properties of nano cuprous oxide, broadens its application scenarios and processability, and has broad industrialization prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a process flow chart for preparing a modified nano-cuprous oxide powder in the present invention;

[0031] Figure 2-1This is a scanning electron microscope image of the modified nano-cuprous oxide powder prepared in Example 1;

[0032] Figure 2-2 is the XRD pattern of the modified nano-cuprous oxide powder prepared in Example 1;

[0033] Figure 3 Figures 2 and 3 are the antioxidant test diagrams of the modified nano-cuprous oxide powder and the unmodified nano-cuprous oxide powder prepared in Example 2; (a, b) are their XRD patterns; (c, d) are their physical images;

[0034] Figure 4-1 This is a scanning electron microscope image of the modified nano-cuprous oxide powder prepared in Example 2;

[0035] Figure 4-2 is the XRD pattern of the modified nano-cuprous oxide powder prepared in Example 2;

[0036] Figure 5-1 This is a scanning electron microscope image of the modified nano-cuprous oxide powder prepared in Example 3;

[0037] Figure 5-2 : is the XRD pattern of the modified nano-cuprous oxide powder prepared in Example 3;

[0038] Figure 6 Graph showing infrared test results of the modified nano-cuprous oxide powder prepared in Examples 1, 2, and 3;

[0039] Figure 7 Graph showing the water dispersibility test results of the modified nano-cuprous oxide powder prepared in Examples 1 and 2;

[0040] Figure 8 This is a graph showing the change in melt extrusion outlet pressure of the modified nano-cuprous oxide powder prepared in Example 2;

[0041] Figure 9 The thermogravimetric performance test diagram of the antibacterial nylon material prepared in Example 4 (left: 0.1wt%, right: 0.3wt%);

[0042] Figure 10 Photos of the modified nano-cuprous oxide powder prepared in Example 2 (left), the antibacterial nylon material prepared in Example 4 (center), and the spinning material made using the modified nano-cuprous oxide powder prepared in Example 2 (right);

[0043] Figure 11 Photos of the antibacterial test of fibers P0-P3 in Example 2 against Escherichia coli (E) and Staphylococcus aureus (S);

[0044] Figure 12This is a graph showing the tensile properties of fibers P0-P3 in Application Example 2 (single fiber diameter 20 μm);

[0045] Figure 13 SEM comparison images of pure nylon monofilament and fibers P0-P3 in Application Example 2;

[0046] Figure 14 This is a diagram showing the anti-mildew performance of acrylic paint using modified cuprous oxide at different concentrations in Example 3. DETAILED DESCRIPTION

[0047] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0048] The following are more detailed implementation cases, which further illustrate the technical solutions of the present invention and the technical effects that can be obtained.

[0049] In the following examples, unless otherwise specified, raw materials, reagents or processing techniques are all conventional commercially available products or conventional processing techniques in the art.

[0050] Example 1:

[0051] A modified nano-cuprous oxide powder, the preparation method of which comprises:

[0052] 100 g of copper sulfate pentahydrate, 42 g of L-ascorbic acid, and 44 g of sodium hydroxide were added to 1000 g of water in sequence, stirred while adding, and reacted at room temperature for 30 min. After filtering and washing, the mixture was poured into an alcohol-water solution with a mass fraction of 60% ethanol.

[0053] 30 g of γ-methacryloyloxypropylmethyldimethoxysilane (Guangdong Yuanfeng Chemical Reagent Co., Ltd., KH571) was added to the solution obtained in the previous step, stirred at room temperature for 20 hours, centrifuged, and dried at 60° C. for 8 hours to finally obtain well-dispersed modified nano-cuprous oxide powder.

[0054] After SEM observation and testing, it was confirmed that the average particle size of the prepared modified powder was 30-50nm. The test characterization diagram is as follows Figure 2-1 , the surface coating is platinum; the product of the first step reaction was taken and tested by XRD. The result showed no impurity peaks, indicating that the product was pure cuprite structure cuprous oxide. The test characterization diagram is as follows Figure 2-2 .

[0055] Example 2:

[0056] A modified nano-cuprous oxide powder, the preparation method of which comprises:

[0057] 80g of copper acetate monohydrate, 45g of L-ascorbic acid, and 45g of sodium hydroxide were added to 1000g of water in sequence, stirring while adding, and reacted at room temperature for 20min. After filtering and washing, the mixture was poured into an alcohol-water solution with a methanol mass fraction of 50%;

[0058] 28 g of γ-aminopropyltriethoxysilane (Shin-Etsu Silicone (Nantong) Co., Ltd., KBM903) was added to the solution obtained in the previous step, stirred at room temperature for 8 hours, centrifuged, and dried at 60° C. for 8 hours to finally obtain well-dispersed modified nano-cuprous oxide powder.

[0059] After SEM observation and testing, it was confirmed that the average particle size of the prepared modified powder was 30-50nm. The test characterization diagram is as follows Figure 4-1 , the surface coating is platinum; the product of the first step reaction was taken and tested by XRD. The result showed no impurity peaks, indicating that the product was pure cuprite structure cuprous oxide. The test characterization diagram is as follows Figure 4-2 .

[0060] Nano-cuprous oxide will slowly oxidize to cupric oxide when placed in air for a long time. Therefore, this embodiment also includes an oxidation resistance test: different samples are exposed to room temperature for a period of time (3 days, 7 days, 14 days, 30 days) and then the effect is observed. The result shows that the oxidation resistance of the modified powder is significantly improved. Figure 3 ,in Figure 3 (c, d) are the actual pictures of modified powder and unmodified powder respectively. Figure 3 (a, b) are their XRD patterns. Experiments show that the XRD spectrum of the nano-cuprous oxide modified by this example still shows cuprous oxide after 30 days, while the unmodified nano-cuprous oxide shows a strong copper oxide peak after 14 days.

[0061] Dispersibility test: The modified Cu2O powder prepared in Example 1 and Example 2 and the Cu2O powder prepared without adding the corresponding silane reagent were respectively prepared into a 0.1wt% aqueous solution. After being ultrasonically treated at 100W for 15 minutes, the solution was transferred to a 100mL transparent beaker and placed in a constant temperature environment (25±1°C). The percentage of the delamination interface height of the suspension was recorded within 24 hours to evaluate the improvement effect of the modification on the anti-sedimentation performance of the particles. The results are shown in Figure 2. Figure 7 As shown in the figure, the modified cuprous oxide aqueous dispersion still had no obvious sedimentation after 72 hours.

[0062] Example 3:

[0063] A modified nano-cuprous oxide powder, the preparation method of which comprises:

[0064] 65 g of copper chloride dihydrate, 44 g of L-ascorbic acid, and 50 g of sodium hydroxide were added to 1000 g of water in sequence, stirring while adding, and reacted at room temperature for 20 min. After filtering and washing, the mixture was poured into an alcohol-water solution with an ethanol mass fraction of 70%;

[0065] 20 g of γ-methacryloxypropyltrimethoxysilane (Nanjing Chuangshi Chemical Additives Co., Ltd., KH570) was added to the solution obtained in the previous step, stirred at room temperature for 20 hours, centrifuged, and dried at 80° C. for 6 hours to finally obtain well-dispersed modified nano-cuprous oxide powder.

[0066] After SEM observation and testing, it was confirmed that the average particle size of the prepared modified powder was 20-40 nm. The test characterization diagram is as follows Figure 5-1 , the surface coating is platinum; the product of the first step reaction was taken and tested by XRD. The result showed no impurity peaks, indicating that the product was pure cuprite structure cuprous oxide. The test characterization diagram is as follows Figure 5-2 .

[0067] The infrared test results of the modified cuprous oxide obtained in the above implementation case are as follows: Figure 6 , indicating that the modifier has been coated on the surface of cuprous oxide powder.

[0068] Example 4

[0069] In this example, the modified nano-cuprous oxide powder prepared in Example 2 was used to prepare an antibacterial nylon material. Specifically, the modified cuprous oxide powder or unmodified cuprous oxide powder (without the addition of γ-aminopropyltriethoxysilane, the remaining steps being the same) was stirred with nylon particles (Haiyang Technology Co., Ltd., semi-matte PA6 chips with a viscosity of 2.7), and then added to a twin-screw extruder (Shanghai Yuesheng Engineering Technology Contracting Co., Ltd., with five screw temperatures of 250°C, 270°C, 270°C, 270°C, and 275°C from the feed end to the discharge end, respectively, and a screw speed of 30 r / min) to obtain the corresponding masterbatch. The cuprous oxide powder was used in amounts of 0.1, 0.3, and 0.5 wt% of the nylon particles (denoted as P1 to P3, respectively, and pure PA6 as P0).

[0070] Application Example 1:

[0071] This example performs a performance test on the masterbatch prepared in Example 4, including:

[0072] Wetting and dispersibility test:

[0073] The masterbatch was put into a twin-screw extruder for melt extrusion (the extrusion conditions were the same as in Example 4). After the masterbatch was melted, it was extruded out by the screw in the form of a melt. A 300-mesh screen was set at the extrusion outlet, and a pressure sensor was set in front of the screen. During the extrusion process, the pressure data fed back by the extruder outlet sensor over time was counted every 5 minutes. The dispersibility of the nano-cuprous oxide powder in nylon was evaluated based on the outlet pressure. The results are as follows: Figure 8 As shown. Figure 8 As can be seen from the figure, for the masterbatch made from unmodified cuprous oxide powder, the pressure at the extrusion outlet continued to rise throughout the extrusion process, reaching approximately 14 MPa at 25 minutes. This resulted in high extrusion difficulty, poor melt fluidity, and severe agglomeration of the nano-cuprous oxide powder. However, for the masterbatch made from modified cuprous oxide powder, the extrusion pressure only reached approximately 5 MPa at 25 minutes, then stabilized. The agglomeration of the nano-cuprous oxide powder was significantly resolved, resulting in better melt fluidity and processability.

[0074] Thermal stability: thermogravimetric method.

[0075] The results are as follows Figure 9 As shown in the figure, it can be seen that as the cuprous oxide content increases, the thermal decomposition temperature of the nylon material increases from 345°C of pure nylon to 363°C (0.1wt%), 370°C (0.3wt%), and 371°C (0.5wt%), respectively. The initial thermal decomposition temperature increases by 26°C, and the thermal stability is enhanced, which is beneficial to increase the processing temperature range of the nylon material and expand the application range of the nylon material.

[0076] Application Example 2:

[0077] In this embodiment, the masterbatch prepared in Example 4 is spun, and the spinning method includes:

[0078] The process was implemented using a ZYPM-M32 twin-screw melt spinning system, with the following specific parameters: (1) raw material pretreatment: the antibacterial masterbatch prepared in Example 4 was placed in a vacuum drying oven and dried at a constant temperature of 120°C for 24 h; (2) melt extrusion: the twin-screw extruder had an aspect ratio of 20:1, temperature zones were set as follows: feed section 240°C → plasticizing section 260°C → homogenizing section 270°C → die section 275°C, and screw speed 180 r / min; (3) spinning: the melt was cooled by side blowing, with a wind speed of 0.5 m / s, wind temperature of 20±2°C, humidity of 65%, oil coating and drawing and shaping, using a 0.3 mm aperture 24-hole spinneret; (4) fiber winding: the fiber was continuously wound by a guide roller and a winder, with a drum speed of 2000 r / min, to obtain drawn cuprous oxide antibacterial nylon fiber. SEM comparison of pure nylon monofilament and fibers P0-P3:

[0079] The surface of pure PA6 fiber (P0) is relatively smooth. As the amount of Cu2O antibacterial agent added increases, more particles gradually appear on the fiber surface. Figure 13 The Cu2O particles on the surface of the corresponding P3 sample are randomly distributed. This surface exposure structure is conducive to the antibacterial agent directly contacting with the pathogens to kill them.

[0080] Plate method test for antibacterial activity: According to GB / T 20944.3-2008 standard, each group was repeated 3 times to ensure data reliability. The antibacterial test process is as follows:

[0081] The first step is the preparation and pre-disinfection of bacterial solution: Staphylococcus aureus and Escherichia coli were selected as test strains in the experiment, and freeze-dried transformed strains within 10 generations were used. Among them, Staphylococcus aureus is a Gram-positive bacterium, and Escherichia coli is a Gram-negative bacterium. The process of bacterial activation is as follows: take an inoculation loop of bacterial moss from the slant of the preserved bacterial strain, streak inoculate it on nutrient agar medium, the culture temperature is 37°C, the culture time is 24h, pick a typical single colony and transfer it to a fresh slant to continue culturing to obtain fresh bacterial moss. When preparing the bacterial suspension, add 5mL of 0.03mol / L PBS buffer (pH=7.2) to the slant, shake it manually 80 times to elute the bacterial moss, and the initial bacterial suspension concentration is adjusted to 1×10 by spectrophotometry. 8 6-5×10 8 6 CFU / mL and use within 4 hours. Further gradient dilution to 2.5×10 5 6-3×10 5 CFU / mL for subsequent experiments. Add 2-3mm diameter glass beads during the dilution process to assist dispersion and ensure a uniform bacterial suspension. Before the experiment begins, sterilize the pipettes, coating plates, culture dishes, etc. used in the antibacterial test in a high-pressure steam autoclave at 121°C for 45 minutes. Place the treated experimental equipment in a sterile operating table with UV sterilization turned on and continue UV sterilization for 30 minutes.

[0082] The second step is contact culture: the experiment is divided into a control group, an antibacterial group, and a blank group. Each group is set up with three replicates. The Escherichia coli group is marked as (E) and the Staphylococcus aureus group is marked as (S). 0.75g of untreated fabric and 70mL of PBS buffer were added to the control flask; 0.75g of antibacterial fabric and an equal amount of buffer were added to the antibacterial group; and only 70mL of buffer was added to the blank group. During the initial inoculation, 5mL of bacterial suspension was added to each of the control and blank groups. The flasks were shaken at 250-300 rpm for 1 minute at 24°C, and the "0" contact time sampling was completed. Subsequently, the antibacterial group added an equal amount of bacterial suspension, and all groups were shaken continuously at 150 rpm for 18 hours in a constant temperature shaker at 24°C.

[0083] Step 3: Antimicrobial Activity Assay: After the contact culture, 1 mL of the test solution was diluted 10-fold in a series. One mL of the appropriate dilution was injected into a sterile plate. Then, 15 mL of nutrient agar was poured over the plate. After solidification at room temperature, the plate was inverted and incubated under incandescent light at 37°C for 48 hours. For colony counts, valid values between 30 and 300 CFU / mL were selected. If the colony count was less than 30, the actual value was recorded. No bacterial growth was recorded as "<1 CFU / mL." The antimicrobial rate was calculated using the following formula.

[0084]

[0085] Where Wt is the average concentration of live bacteria in the control group, and Qt is the average concentration of live bacteria in the antibacterial group. According to the GB / T20944.3-2008 standard, only when the sterilization effect of antibacterial fiber on Escherichia coli and Staphylococcus aureus reaches more than 70% can it be considered that the sample has antibacterial effect.

[0086] The test results are shown in Table 1. Figure 11 shown.

[0087] Table 1

[0088]

[0089]

[0090] From Table 1, Figure 11 It can be seen that the masterbatch made from modified cuprous oxide powder has a good antibacterial effect against Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) at an addition amount of 0.5wt%.

[0091] Tensile properties:

[0092] Test procedures (based on ASTM D3822, US standard): Elongation at break of nylon monofilament was measured using an MX-0850 single-filament fiber tensile tester. Test conditions were set as follows: initial clamping distance of 10 cm, and a tensile rate of 0.25 mm / s. Randomly selected stretched fiber samples were tested five times, and the arithmetic mean of these five measurements was used to ensure data reliability. The final results were the breaking strength and elongation of the samples.

[0093] The results are as follows Figure 12 As shown in the figure, the elongation at break of the fiber samples of pure PA6, 0.1wt% antibacterial agent and 0.3wt% antibacterial agent is stable at about 35%, while when the amount of antibacterial agent added is increased to 0.5wt%, the elongation at break of the fiber drops to 30%, which is 15% lower than the elongation at break of pure PA6. Figure 12The horizontal axis shows that the breaking strength of all samples remains around 5.37 cN / dtex, indicating that within the antibacterial agent addition concentration range set in the experiment, the introduction of Cu2O has no significant effect on the intrinsic strength of the fiber.

[0094] Application Example 3: Anti-mildew performance of coatings

[0095] The modified cuprous oxide obtained in Example 1 was directly added to an acrylic paint (E0503, manufactured by Shenzhen Jitian Chemical Co., Ltd.). Three concentrations of the antibacterial agent (modified cuprous oxide) were set: 1 wt %, 1.5 wt %, and 2 wt %.

[0096] Test steps (refer to national standard GB / T1741-2020): First, prepare a 5.0*5.0cm glass plate, wipe it with alcohol and dry it in advance, and apply the paint film on the sandblasted and cleaned aluminum plate with a thickness of 500μm. Dry it naturally and set aside. Secondly, dilute the spores (a mixed strain of six types of fungi: Aspergillus niger, Aspergillus flavus, Cladosporium herbarium, Paecilomyces variotii, Penicillium citrinum, and Trichoderma viride) with nutrient salt solution, adjust the concentration of each spore to 1.0*106 / ml, and then mix them in equal amounts. Prepare nutrient salt using a 9mm diameter disposable sterile plastic plate with a culture medium thickness of 4mm-6mm. Place the pretreated 5*5cm paint film in the center of the nutrient salt culture medium, spray the prepared mixed spore suspension on the entire paint film and plate agar, and the inoculation volume of each plate is 0.5ml. The incubation temperature is 28℃, the humidity is not less than 85%, and the results are observed after 28 days.

[0097] Observation results and evaluation: 0 = no growth, 1 = trace growth, 2 = growth with 1-10% area coverage, 3 = growth with 11-30% area coverage, 4 = growth with 31-70% area coverage, 5 = growth with 71-100% area coverage.

[0098] Test results: see Figure 14 From left to right in the figure are three nano cuprous oxide concentrations of 1wt%, 1.5wt%, and 2wt%. No mold grows on the paint films of the three concentrations, and the mildew resistance level reaches level 0.

[0099] Antibacterial and washable test:

[0100] After washing the fiber samples, the antibacterial properties were tested using the above-mentioned plate. The standard washing method was still in accordance with the household drum washing machine washing method in 10.1.2 of GB / T20944.3-2008:

[0101] From the large antimicrobial fabric sample, take a sample of at least 20g. Test conditions are 40°C ± 3°C, a bath ratio of 1:30, and a 0.2% AATCC 1993 WOB phosphate-free standard detergent. The following procedure is equivalent to five washes (using a 20g sample as an example; in actual testing, the water volume and detergent should be increased proportionally based on the sample size): Add 6L of hot water at 40°C ± 3°C to the washing machine, add 20g of the sample and 180g of the accompanying fabric, and 12g of detergent. Wash for 25 minutes. Drain, then refill with 6L of tap water for 2 minutes. Remove the fabric and spin dry it with centrifugation for 1 minute. Refill with 6L of tap water for 2 minutes, remove the fabric, and spin dry it with centrifugation for 1 minute. Repeat this procedure for the specified number of washes. To prevent residual detergent from interfering with the antimicrobial performance test, thoroughly rinse the sample at the end of the final wash cycle and then air dry or dry it in a tumble dryer.

[0102] The results are shown in Table 2. After being washed 150 times, the antibacterial nylon fiber still maintains effective antibacterial effects against Staphylococcus aureus (needs >85%), Escherichia coli (needs >70%), and Candida albicans (needs >70%).

[0103] Table 2 (Nano-cuprous oxide addition amount is 0.5wt%)

[0104]

[0105] Antiviral test, where the test virus is H1N1 influenza virus and the host cell is canine kidney host cell:

[0106] 1) Observe the confluence of the cell culture prepared in the 96-well plate under a microscope. If the cells are confluent, aspirate the growth medium from the plate. Add 0.1 mL of maintenance medium and gently swirl to rinse the cell surface. Remove the medium and repeat the washing procedure two more times.

[0107] 2) Inoculate 0.1 mL of the test virus eluted suspension and the diluted suspension into 8 wells, for example, inoculate the basic virus suspension into the first 8 wells, and inoculate the 1 / 10 diluted virus suspension into the second 8 wells, and inoculate the last 8 wells with pure maintenance medium to verify the medium.

[0108] 3) Place the microplate in a CO2 incubator at an appropriate temperature for 1 hour to allow the cells to absorb the virus. Aspirate the supernatant from the plate. Add 0.1 mL of maintenance medium, rinse the cell surface with this medium, and aspirate the excess maintenance medium.

[0109] 4) Add 0.2 mL of trypsin-containing maintenance medium for influenza virus, and place the previously obtained microplate in a CO2 incubator and store at an appropriate temperature for 7 days as required.

[0110] 5) Observe the cytopathic effect and record the results. Repeat three times. The results are shown in Table 3.

[0111] According to the standard ISO18184:2019: when the antiviral activity value 3.0>Mv≥2.0, the effect is good; when the antiviral activity value Mv≥3.0, the effect is excellent.

[0112] Table 3 (Nano-cuprous oxide addition amount is 0.5wt%)

[0113]

[0114] Antiviral activity: Mv = lg (Va) - lg (Vc). The average Mv obtained from the data in the table is 2.75, and the corresponding antiviral activity rate is 99.82%, which shows a good antiviral effect.

[0115] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A method for preparing modified nano cuprous oxide, characterized in that: include: A copper source, a reducing agent, and a pH regulator are synthesized and reacted in water; the obtained solid phase product is stirred and reacted with a silane modifier in an alcohol aqueous solution, and the modified nano-cuprous oxide is obtained by separation and purification; The silane modifier is selected from one of γ-methacryloxypropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-aminoethyl-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane or γ-methacryloxypropyltrimethoxysilane.

2. The method for preparing modified nano cuprous oxide according to claim 1, wherein The mass ratio of the copper source to the silane modifier is 50-150:1-30.

3. The preparation method of modified nano cuprous oxide according to claim 1, wherein The copper source is selected from at least one of copper acetate monohydrate, copper chloride dihydrate, copper nitrate trihydrate or copper sulfate pentahydrate.

4. The method for preparing modified nano cuprous oxide according to claim 1, wherein The reducing agent is selected from one of L-ascorbic acid, hydrazine hydrate, sodium borohydride or sodium thiosulfate.

5. The method for preparing modified nano cuprous oxide according to claim 1, wherein The pH regulator is selected from sodium hydroxide, potassium hydroxide, urea or ammonia water.

6. The method for preparing modified nano cuprous oxide according to claim 1, wherein: The mass ratio of the copper source, the reducing agent and the pH regulator is 5-15:3-8:3-8.

7. The method for preparing modified nano cuprous oxide according to claim 1, wherein: In the synthesis reaction, the reaction temperature is room temperature and the reaction time is 15 to 60 minutes; In the stirring reaction, the reaction temperature is room temperature, the reaction time is 4 to 48 hours, and the alcohol aqueous solution is an aqueous solution of 30 to 70 wt% methanol or ethanol.

8. The method for preparing modified nano cuprous oxide according to claim 1, wherein: In the synthesis reaction, the initial concentration of copper ions is 0.05 to 1 mol / L; in the stirring reaction, the mass of the alcohol-water solution is not less than 10 times the mass of the copper source.

9. An application of modified nano-cuprous oxide prepared by the method according to any one of claims 1 to 8, characterized in that: The nano cuprous oxide is used for preparing antibacterial fibers or antifouling coatings.

10. The use of modified nano cuprous oxide according to claim 9, characterized in that: The antibacterial fiber is an antibacterial nylon fiber, and the preparation method of the antibacterial nylon fiber comprises: blending and extruding nano cuprous oxide and nylon material; The extrusion conditions are selected from one of the following conditions: (1) Use a single screw extruder with an aspect ratio of >40:1, a screw speed of 25-40 r / min, a zone 1 temperature of 250-280°C, a zone 2 to 4 temperature of 265-272°C, and a zone 5 temperature of 273-280°C; (2) A twin-screw extruder is used with an aspect ratio of >30:1, a screw speed of 25-40 r / min, a temperature in zone 1 of 250-280°C, a temperature in zones 2 to 4 of 265-280°C, and a temperature in zone 5 of 273-280°C.

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