Micromolecule coated nano zinc oxide monodisperse antibacterial colloid and preparation method thereof

Abstract

The invention belongs to the technical field of nano-antibacterial materials, and provides a micromolecule coated nano-zinc oxide monodisperse antibacterial colloid, the colloid comprises nano-zinc oxide powder, a dispersant and water, the total mass ratio of the nano-zinc oxide powder to the dispersant is (1: 1)-(10: 1), the mass ratio of the nano-zinc oxide powder to the water is (1: 100)-(1: 10000), the total mass ratio of the nano-zinc oxide powder to the dispersant is (1: 1)-(1: 10000), and the mass ratio of the nano-zinc oxide powder to the water is (1: 100)-(1: 10000). The diameter of the nano zinc oxide particles in the colloid is 60 nm to 100 nm. According to the invention, the micro-molecular dispersant is introduced to modify the nano-zinc oxide, and the total mass ratio of the nano-zinc oxide powder to the dispersant and the mass ratio of the nano-zinc oxide powder to water are optimized, so that the nano-zinc oxide can be completely coated with the nano-zinc oxide powder by micro-molecules, and the surface energy of the nano-zinc oxide and Van der Waals force and electrostatic attraction among particles are reduced; and the dispersion performance of the nano-zinc oxide in water can be improved.

Description

Technical Field

[0001] This invention relates to the field of nano-antibacterial materials technology, specifically to a small molecule-coated nano-zinc oxide monodisperse antibacterial colloid and its preparation method. Background Technology

[0002] Nano zinc oxide is a novel inorganic material with unique properties in catalysis, optics, and magnetism, and it has wide applications in chemical industries such as ceramics, rubber, and coatings. Nano zinc oxide releases free electrons, which react with oxygen to generate reactive oxygen species. Through oxidation, it effectively kills most bacteria and is commonly used as an antibacterial agent in daily-use plastics, building coatings, food packaging, and ceramics.

[0003] However, due to the small size and surface effects of nanomaterials, they possess large specific surface areas and surface energies, making them highly prone to aggregation. The size of nano-zinc oxide significantly impacts its bactericidal ability. To reduce the size of nano-zinc oxide, existing technologies typically employ mechanical dispersion methods. However, mechanically dispersed nanomaterials tend to have large particle sizes, poor stability, and frequent aggregation. Therefore, using mechanically dispersed nano-zinc oxide as a nanoscale material suffers from drawbacks such as easy aggregation and poor dispersibility in water, limiting its application effectiveness. Thus, finding a method to reduce the particle size of nano-zinc oxide as a nanoscale material, eliminate aggregation, and improve the dispersion stability of nano-zinc oxide has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a small-molecule coated nano-zinc oxide monodisperse antibacterial colloid and its preparation method. The nano-zinc oxide monodisperse antibacterial colloid obtained by this invention has small particle size, strong dispersion stability, excellent antibacterial properties, and is environmentally friendly.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a small molecule-coated nano-zinc oxide monodisperse antibacterial colloid, the colloid comprising: nano-zinc oxide powder, dispersant, and water, wherein the total mass ratio of nano-zinc oxide powder to dispersant is (1:1)-(10:1), the mass ratio of nano-zinc oxide powder to water is (1:100)-(1:10000), and the diameter of the nano-zinc oxide particles in the colloid is 60nm-100nm.

[0007] This invention modifies nano-zinc oxide by introducing a small-molecule dispersant. By optimizing the total mass ratio of nano-zinc oxide powder to dispersant and the mass ratio to water, the small molecules can completely coat the nano-zinc oxide powder, reducing the surface energy and interparticle van der Waals forces and electrostatic attraction, thus improving the dispersion performance of nano-zinc oxide in water. Furthermore, by optimizing the particle size of the nano-zinc oxide and limiting it to the range of 60nm-100nm, the nano-zinc oxide material exhibits higher dispersion performance in water, overcoming the tendency of nanomaterials to aggregate due to their high surface energy and large specific surface area, and ensuring long-term stability of the material size.

[0008] As a preferred embodiment of the first aspect, the total mass ratio of the nano zinc oxide powder to the dispersant can be any one of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1, or a range between two of them. More preferably, the total mass ratio of the nano zinc oxide to the small molecules is (2:1) to (8:1).

[0009] In a preferred embodiment of the first aspect, the mass ratio of the nano-zinc oxide powder to water can be any one of, or a range between, 1:100, 1:250, 1:500, 1:1000, 1:1500, 1:2000, 1:2500, 1:3000, 1:3500, 1:4000, 1:5000, 1:6000, 1:7000, 1:7500, 1:8000, 1:9000, or 1:10000. More preferably, the mass ratio of the nano-zinc oxide powder to water is (1:250) to (1:10000).

[0010] As a preferred embodiment of the first aspect, the diameter of the nano zinc oxide particles can be any one of 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, or a range between two of them.

[0011] As a preferred embodiment of the first aspect, the dispersant is a composite dispersant composed of sodium hexametaphosphate, sodium dodecylbenzenesulfonate (SDS) (SHMP), polyethylene glycol (PEG), and sodium tripolyphosphate (STTP).

[0012] In a preferred embodiment of the first aspect, the mass ratio of the components in the composite dispersant is: SHMP:SDS:PEG:STTP = (5-1):(4-1):(3-1):1. More preferably, their mass ratio is: SHMP:SDS:PEG:STTP = 3:2:1:1. Experimental studies have shown that the coating effect of the combined dispersant is better than that of the single dispersant, resulting in a more uniform and transparent colloid.

[0013] In a preferred embodiment of the first aspect, the purity of the small molecule dispersants is all AR grade.

[0014] Secondly, the present invention provides a method for preparing the small molecule-coated nano zinc oxide monodisperse antibacterial colloid described in the first aspect, specifically including the following steps: placing the ball milling media into a ball milling jar, then adding nano zinc oxide powder, dispersant and water, turning on the ball mill, ball milling for 2h-10h, removing the ball milling jar, removing the ball milling media, and obtaining the small molecule-coated nano zinc oxide monodisperse antibacterial colloid.

[0015] This invention utilizes a ball milling process to mix nano-zinc oxide, a small-molecule dispersant, and water, followed by stirring. This effectively coats the nano-zinc oxide with the small-molecule dispersant, resulting in colloidal particles with a nanoparticle size of 60nm-100nm. The ball milling-chemical modification of nano-zinc oxide significantly improves its dispersion performance in water, overcoming secondary agglomeration caused by thermodynamic and kinetic instability of nanomaterials and promoting the full expression of its superior properties. The small-molecule dispersant, through mechanical-chemical modification, coats the nano-zinc oxide particles, reducing van der Waals forces between particles and preventing secondary agglomeration of the ball-milled zinc oxide. The resulting colloid also exhibits excellent dispersibility in water, and the nano-zinc oxide colloid prepared by this invention can be stably stored for extended periods.

[0016] In a preferred embodiment of the second aspect, the mass ratio of the nano-zinc oxide to the milling media is (1:100)-(1:10000); the mass ratio of the nano-zinc oxide powder to the milling media can be any one of, or a range between, 1:100, 1:250, 1:500, 1:1000, 1:1500, 1:2000, 1:2500, 1:3000, 1:3500, 1:4000, 1:5000, 1:6000, 1:7000, 1:7500, 1:8000, 1:9000, and 1:10000. Experimental studies have shown that the mass ratio of nano-zinc oxide to the milling media affects the dispersion morphology of nano-zinc oxide in water. Controlling the mass ratio of nano-zinc oxide to the milling media can yield a more uniform and transparent colloid, resulting in a better antibacterial effect.

[0017] As a preferred embodiment of the second aspect, the total mass ratio of nano zinc oxide powder to dispersant is (1:1)-(10:1), and the mass ratio of nano zinc oxide powder to water is (1:100)-(1:10000).

[0018] In a preferred embodiment of the second aspect, the milling media is zirconia beads with a particle size of 0.1 mm to 0.5 mm, specifically any one or a range between 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm. More preferably, the particle size is 0.1 mm to 0.2 mm. Experimental studies have shown that the particle size of the milling media affects the dispersion morphology of nano-zinc oxide in water. Controlling the particle size of the milling media can yield a more uniform and transparent colloid, resulting in a better antibacterial effect.

[0019] In a preferred embodiment of the second aspect, the rotational speed of the ball mill is between 200 r / min and 800 r / min, and the rotational speed is any one or a range between two of 200 r / min, 300 r / min, 400 r / min, 500 r / min, 600 r / min, 700 r / min, and 800 r / min. More preferably, the rotational speed of the ball mill is 700 r / min.

[0020] In a preferred embodiment of the second aspect, the ball milling time can be any one of 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, and 10h, or a range between two of these values. More preferably, the ball milling time is 3h-6h. Experimental studies have shown that the length of the ball milling time affects the dispersion morphology of nano-zinc oxide in water. Controlling the ball milling time can yield a more uniform and transparent colloid, resulting in a better antibacterial effect. In a preferred embodiment of the second aspect, the ball milling temperature is 20℃-40℃, and the ball milling temperature can be any one of 20℃, 25℃, 30℃, 35℃, and 40℃, or a range between two of these values.

[0021] As a preferred embodiment of the second aspect, the liquid pH is maintained at 9-9.5 during ball milling.

[0022] Thirdly, the present invention provides the application of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid described in the first aspect in antibacterial applications.

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

[0024] This invention overcomes the tendency of nanomaterials to agglomerate by employing a ball milling-chemical modification method. Large nano-zinc oxide particles are dispersed into smaller particles through high-energy ball milling. Then, a small-molecule dispersant is introduced to modify the nano-zinc oxide particles, coating them with the dispersant. This reduces the surface energy of the nano-zinc oxide, improves its dispersion performance in water, and ensures long-term size stability. The small-molecule dispersant, through mechanical-chemical modification, coats the nano-zinc oxide particles, reducing van der Waals forces and electrostatic attraction between particles, thus preventing agglomeration of the dispersed nano-zinc oxide after ball milling.

[0025] The colloid of this invention also has antibacterial properties, exhibiting good antibacterial activity against both Staphylococcus aureus and Escherichia coli. Its minimum inhibitory concentration (MIC) against Staphylococcus aureus is 39-98 ppm, and against Escherichia coli it is 36-312 ppm, which is far lower than the inhibitory concentration of commercially available nano zinc oxide. This improves upon the current shortcomings of nano zinc oxide, which has weak antibacterial performance when directly applied to antibacterial materials.

[0026] The method for preparing nano-zinc oxide colloids in this invention is simple, easily scalable for industrial production, and uses inexpensive reagents. The resulting nano-zinc oxide colloids exhibit good stability and excellent dispersibility in water, further broadening the application fields of nano-zinc oxide and making it more suitable for research. Furthermore, it has no environmental impact, and the resulting solutions can be recovered. Attached Figure Description

[0027] Figure 1 Photographs of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid (a) prepared in Example 1 and the small molecule-coated nano zinc oxide monodisperse antibacterial colloid (b) prepared in Comparative Example 1;

[0028] Figure 2 This is a schematic diagram of the Tyndall effect in the colloid of Example 1;

[0029] Figure 3 This is a TEM image of the colloid from Example 1. Detailed Implementation

[0030] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] Unless otherwise specified, the experimental methods used in the examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified. The zinc oxide involved is a commercially available agglomerate raw material with a purity of 99.98%; the molecular weight of the sodium hexametaphosphate involved is 611.77; the molecular weight of the sodium dodecylbenzenesulfonate (SDS) involved is 288.38; the CAS Registry Number of the polyethylene glycol involved is 25322-68-3; and the molecular weight of the sodium tripolyphosphate involved is 367.864.

[0032] Example 1:

[0033] This embodiment provides a small molecule-coated nano-zinc oxide monodisperse antibacterial colloid, the colloid comprising: nano-zinc oxide powder, dispersant, and water, wherein the total mass ratio of nano-zinc oxide powder to dispersant is 5:1, the mass ratio of nano-zinc oxide powder to water is 1:1000, and the average diameter of the nano-zinc oxide particles in the colloid is 90 nm.

[0034] The preparation method of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid in this embodiment is as follows:

[0035] Zirconia beads were placed in a 100ml ball mill jar, along with 0.5g of commercially available nano zinc oxide powder, AR-grade small molecule reagent, and deionized water. The jar was then set up with a ball mill (model: UBE-V2L, Hunan Deco Equipment Co., Ltd.). During milling, the liquid pH was maintained between 9 and 9.5. After turning off the ball mill, the jar was removed, and the milling media were discarded, yielding a small molecule-coated nano zinc oxide antibacterial colloid. A digital photograph of the actual product is shown below. Figure 1 As shown on the left.

[0036] The total amount of small molecule dispersant added is 0.1g; the small molecule dispersant is a composite dispersant composed of sodium hexametaphosphate (SHMP), sodium dodecylbenzenesulfonate (SDS), polyethylene glycol (PEG), and sodium tripolyphosphate (STTP); and the mass ratio is SHMP:SDS:PEG:STTP = 3:2:1:1;

[0037] The zirconium oxide beads have a particle size of 0.3 mm, and the mass ratio of nano zinc oxide to the ball milling media is 1:100.

[0038] The ball milling speed was 500 r / min, the milling time was 3 hours, and the milling temperature was 30℃.

[0039] Example 2:

[0040] This embodiment provides a small molecule-coated nano-zinc oxide monodisperse antibacterial colloid, the colloid comprising: nano-zinc oxide powder, dispersant, and water, wherein the total mass ratio of nano-zinc oxide powder to dispersant is 1:1, the mass ratio of nano-zinc oxide powder to water is 1:100, and the average diameter of the nano-zinc oxide particles in the colloid is 80 nm.

[0041] The preparation method of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid in this embodiment is as follows:

[0042] Zirconia beads were placed in a 100ml ball mill jar, along with 0.5g of commercially available nano zinc oxide powder, AR-grade small molecule reagent, and deionized water. The jar was then set up with a ball mill (model: UBE-V2L, Hunan Deco Equipment Co., Ltd.). During milling, the liquid pH was maintained between 9 and 9.5. After turning off the ball mill, the jar was removed, and the milling media were discarded, yielding a small molecule-coated nano zinc oxide antibacterial colloid. A digital photograph of the actual product is shown below. Figure 1 As shown on the left.

[0043] The total amount of small molecule dispersant added is 0.5g; the small molecule dispersant is a composite dispersant composed of sodium hexametaphosphate (SHMP), sodium dodecylbenzenesulfonate (SDS), polyethylene glycol (PEG), and sodium tripolyphosphate (STTP); and the mass ratio is SHMP:SDS:PEG:STTP = 5:4:3:1;

[0044] The zirconium oxide beads have a particle size of 0.1 mm, and the mass ratio of nano zinc oxide to the ball milling media is 1:1000;

[0045] The ball milling speed was 200 r / min, the milling time was 5 h, and the milling temperature was 20℃.

[0046] Example 3:

[0047] This embodiment provides a small molecule-coated nano-zinc oxide monodisperse antibacterial colloid, the colloid comprising: nano-zinc oxide powder, dispersant, and water, wherein the total mass ratio of nano-zinc oxide powder to dispersant is 6:1, the mass ratio of nano-zinc oxide powder to water is 1:500, and the average diameter of the nano-zinc oxide particles in the colloid is 100 nm.

[0048] The preparation method of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid in this embodiment is as follows:

[0049] Zirconia beads were placed in a 100ml ball mill jar, along with 0.5g of commercially available nano zinc oxide powder, AR-grade small molecule reagent, and deionized water. The jar was then set up with a ball mill (model: UBE-V2L, Hunan Deco Equipment Co., Ltd.). During milling, the liquid pH was maintained between 9 and 9.5. After turning off the ball mill, the jar was removed, and the milling media were discarded, yielding a small molecule-coated nano zinc oxide antibacterial colloid. A digital photograph of the actual product is shown below. Figure 1 As shown on the left.

[0050] The total amount of small molecule dispersant added is 0.083g; the small molecule dispersant is a composite dispersant composed of sodium hexametaphosphate (SHMP), sodium dodecylbenzenesulfonate (SDS), polyethylene glycol (PEG), and sodium tripolyphosphate (STTP); and the mass ratio is SHMP:SDS:PEG:STTP = 1:1:1:1.

[0051] The zirconium oxide beads have a particle size of 0.4 mm, and the mass ratio of nano zinc oxide to the ball milling media is 1:5000;

[0052] The ball milling speed was 800 r / min, the milling time was 5 h, and the milling temperature was 35℃.

[0053] Example 4:

[0054] This embodiment provides a small molecule-coated nano-zinc oxide monodisperse antibacterial colloid, the colloid comprising: nano-zinc oxide powder, dispersant, and water, wherein the total mass ratio of nano-zinc oxide powder to dispersant is 5:1, the mass ratio of nano-zinc oxide powder to water is 1:5000, and the average diameter of the nano-zinc oxide particles in the colloid is 60 nm.

[0055] The preparation method of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid in this embodiment is as follows:

[0056] Zirconia beads were placed in a 100ml ball mill jar, along with 0.5g of commercially available nano zinc oxide powder, AR-grade small molecule reagent, and deionized water. The jar was then set up with a ball mill (model: UBE-V2L, Hunan Deco Equipment Co., Ltd.). During milling, the liquid pH was maintained between 9 and 9.5. After turning off the ball mill, the jar was removed, and the milling media were discarded, yielding a small molecule-coated nano zinc oxide antibacterial colloid. A digital photograph of the actual product is shown below. Figure 1 As shown on the left.

[0057] The total amount of small molecule dispersant added is 0.1g; the small molecule dispersant is a composite dispersant composed of sodium hexametaphosphate (SHMP), sodium dodecylbenzenesulfonate (SDS), polyethylene glycol (PEG), and sodium tripolyphosphate (STTP); and the mass ratio is SHMP:SDS:PEG:STTP = 2:3:3:1;

[0058] The zirconium oxide beads have a particle size of 0.1 mm, and the mass ratio of nano zinc oxide to the ball milling media is 1:800;

[0059] The ball milling speed was 700 r / min, the milling time was 4 hours, and the milling temperature was 35℃.

[0060] Example 5:

[0061] This embodiment provides a small molecule-coated nano-zinc oxide monodisperse antibacterial colloid, the colloid comprising: nano-zinc oxide powder, dispersant, and water, wherein the total mass ratio of nano-zinc oxide powder to dispersant is 10:1, the mass ratio of nano-zinc oxide powder to water is 1:10000, and the average diameter of the nano-zinc oxide particles in the colloid is 90 nm.

[0062] The preparation method of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid in this embodiment is as follows:

[0063] Zirconia beads were placed in a 100ml ball mill jar, along with 0.5g of commercially available nano zinc oxide powder, AR-grade small molecule reagent, and deionized water. The jar was then set up with a ball mill (model: UBE-V2L, Hunan Deco Equipment Co., Ltd.). During milling, the liquid pH was maintained between 9 and 9.5. After turning off the ball mill, the jar was removed, and the milling media were discarded, yielding a small molecule-coated nano zinc oxide antibacterial colloid. A digital photograph of the actual product is shown below. Figure 1 As shown on the left.

[0064] The total amount of small molecule dispersant added is 0.05g; the small molecule dispersant is a composite dispersant composed of sodium hexametaphosphate (SHMP), sodium dodecylbenzenesulfonate (SDS), polyethylene glycol (PEG), and sodium tripolyphosphate (STTP); and the mass ratio is SHMP:SDS:PEG:STTP = 2:4:1:1;

[0065] The zirconium oxide beads have a particle size of 0.5 mm, and the mass ratio of nano zinc oxide to the ball milling media is 1:10000;

[0066] The ball milling speed was 800 r / min, the milling time was 10 h, and the milling temperature was 40℃.

[0067] Comparative Example 1

[0068] The difference between Comparative Example 1 and Example 1 is that the small molecule dispersant is sodium hexametaphosphate, the total amount added remains the same, and the rest is the same as in Example 1.

[0069] Comparative Example 2

[0070] The difference between Comparative Example 2 and Example 1 is that the small molecule dispersant is sodium dodecylbenzenesulfonate, the total amount added remains the same, and the rest is the same as in Example 1.

[0071] Comparative Example 3

[0072] The difference between Comparative Example 3 and Example 1 is that the small molecule dispersant is polyethylene glycol, the total amount added remains the same, and the rest is the same as in Example 1.

[0073] Comparative Example 4

[0074] The difference between Comparative Example 4 and Example 1 is that the small molecule dispersant is sodium tripolyphosphate, the total amount added remains the same, and the rest is the same as in Example 1.

[0075] Comparative Example 5

[0076] The difference between Comparative Example 5 and Example 1 is that the small molecule dispersant is a composite dispersant composed of sodium hexametaphosphate and sodium dodecylbenzenesulfonate; and the mass ratio is SHMP:SDS = 3:2, the total amount added remains unchanged, and the rest is the same as in Example 1.

[0077] Comparative Example 6

[0078] The difference between Comparative Example 6 and Example 1 is that the small molecule dispersant is a composite dispersant composed of sodium dodecylbenzenesulfonate (SDS) and polyethylene glycol (PEG); and the mass ratio is SDS:PEG = 2:1, the total amount added remains unchanged, and the rest is the same as in Example 1.

[0079] Comparative Example 7

[0080] The difference between Comparative Example 7 and Example 1 is that the small molecule dispersant is a composite dispersant composed of sodium hexametaphosphate (SHMP), sodium dodecylbenzenesulfonate (SDS), and polyethylene glycol (PEG); and the mass ratio is SHMP:SDS:PEG = 3:2:1, the total amount added remains unchanged, and the rest is the same as in Example 1.

[0081] Comparative Example 8

[0082] The difference between Comparative Example 8 and Example 1 is that the small molecule dispersant is a composite dispersant composed of sodium dodecylbenzenesulfonate (SDS), polyethylene glycol (PEG), and sodium tripolyphosphate (STTP); and the mass ratio is SDS:PEG:STTP = 2:1:1, the total amount added remains unchanged, and the rest is the same as in Example 1.

[0083] Comparative Example 9

[0084] The difference between Comparative Example 9 and Example 1 is that: SHMP:SDS:PEG:STTP = 8:5:4:1, the total amount added remains the same, and the rest is the same as Example 1.

[0085] Comparative Example 10

[0086] The difference between Comparative Example 10 and Example 1 is that: SHMP:SDS:PEG:STTP = 1:1:1:2, the total amount added remains the same, and the rest is the same as Example 1.

[0087] Comparative Example 11

[0088] The difference between Comparative Example 11 and Example 1 is that no small molecule dispersant is added, while the rest is the same as Example 1.

[0089] Comparative Example 12

[0090] The difference between Comparative Example 12 and Example 1 is that mechanical stirring is used, and the specific operation is as follows:

[0091] Mix 0.5g of commercially available nano zinc oxide powder, 0.05g of AR-grade small molecule reagent sodium hexametaphosphate, and 50g of deionized water in a 50ml beaker and stir at high speed for 1 hour at a stirring speed of 500r / min to obtain nano zinc oxide aqueous antibacterial colloid.

[0092] Comparative Example 13

[0093] The difference between Comparative Example 13 and Example 1 is that ultrasonic dispersion is used, and the specific operation is as follows:

[0094] Mix 0.5g of commercially available nano zinc oxide powder, 0.05g of AR-grade small molecule reagent sodium hexametaphosphate, and 50g of deionized water, place the mixture in a 50ml sample bottle, and ultrasonically disperse for 30min to obtain nano zinc oxide aqueous antibacterial colloid.

[0095] Comparative Example 14

[0096] The difference between Comparative Example 14 and Example 1 is that the total mass ratio of nano zinc oxide to small molecules is 0.5:1, and the rest is the same as Example 1.

[0097] Comparative Example 5

[0098] The difference between Comparative Example 15 and Example 1 is that the total mass ratio of nano zinc oxide to small molecules is 12:1, and the rest is the same as Example 1.

[0099] Comparative Example 16

[0100] The difference between Comparative Example 16 and Example 1 is that the mass ratio of nano zinc oxide to water is 0.5:100, and the rest is the same as in Example 1.

[0101] Comparative Example 17

[0102] The difference between Comparative Example 17 and Example 1 is that the mass ratio of nano zinc oxide to water is 1:10500, and the rest is the same as in Example 1.

[0103] Comparative Example 18

[0104] The difference between Comparative Example 8 and Example 1 is that the mass ratio of nano zinc oxide to ball milling media is 0.5:100, and the rest is the same as in Example 1.

[0105] Comparative Example 19

[0106] The difference between Comparative Example 9 and Example 1 is that the mass ratio of nano zinc oxide to ball milling media is 1:10500, and the rest is the same as in Example 1.

[0107] Test case

[0108] 1. Particle size test: The colloids prepared in the examples and comparative examples were tested with a particle size analyzer to obtain the average particle size;

[0109] 2. Antibacterial Test: A portion of the above-mentioned small-molecule coated nano-zinc oxide antibacterial colloid was taken and subjected to a minimum inhibitory concentration (MIC) test according to Section 2.1.8.4 of the 2002 edition of the "Disinfection Technical Specifications". Tested bacteria: Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213.

[0110] 3. Stability test: No sedimentation occurred after standing for 30 min, 1 h, and 5 h, and no obvious stratification was observed after standing for 15 days.

[0111] Table 1: Test Results of Examples and Comparative Examples

[0112]

[0113]

[0114] As shown in Table 1, the colloids in the examples exhibit good antibacterial properties. Examples 1-5 show better antibacterial effects compared to Comparative Examples 1-8, which may be due to the synergistic effect of the four small-molecule dispersants, improving the coating rate of the dispersants on oxidants. Therefore, Comparative Examples 9 and 10 optimized the ratio of the four dispersants. The results showed that the synergistic effect was best when the mass ratio of the four dispersants was SHMP:SDS:PEG:STTP = 3:2:1:1. Comparative Example 11, due to the absence of a small-molecule dispersant, caused the nano-zinc oxide to agglomerate, reducing its dispersion stability. Comparative Examples 12 and 13 used mechanical or ultrasonic methods to make the nano-zinc oxide particle size greater than 300 nm, causing the nano-zinc oxide to agglomerate and reducing its dispersion stability, thus affecting its antibacterial properties. The preparation process parameters for the colloids of this invention, including the total mass of the dispersant, the mass of added water, the size of the milling media, the milling speed, and the milling time, are particularly important. In Comparative Example 14, the total mass of the dispersant was too small, failing to completely coat the nano-zinc oxide, leading to agglomeration. In Comparative Example 15, the total mass of the dispersant was too large, potentially causing a decrease in the absolute value of the Zeta potential, thereby reducing the stabilizing effect of electrostatic repulsion and affecting the stability of the slurry. The viscosity of the suspension also increased, possibly causing agglomeration. The stability of the nano-colloidal water is closely related to its concentration. When the concentration of the nano-colloidal water is too low, its stability may be affected. Therefore, in Comparative Example 16, the excessive addition of water may dilute the effective components of the nano-colloid, thus affecting the antibacterial properties of the colloid. In Comparative Example 17, the insufficient addition of water caused the colloidal particles to easily aggregate and precipitate, thus affecting its application effect. The quality of the added grinding media has a significant impact on the grinding effect of the ball mill. The quality of the grinding media directly affects the grinding efficiency and product quality. In Comparative Example 18, if the added grinding media is too small, the grinding effect may be poor, thus affecting the quality of the final product. In Comparative Example 19, if the added grinding media is too large, the ball mill will be difficult to start. Even if it is successfully started, it will result in excessive power consumption, thereby increasing energy consumption and equipment load.

[0115] In summary, the mechanical-chemical modification of small molecules by the present invention reduces the particle size of zinc oxide nanoparticles. At the same time, the synergistic antibacterial effect of the small molecule dispersant and zinc oxide nanoparticles results in better antibacterial effects for the well-dispersed zinc oxide nanoparticle colloids.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A small molecule-coated nano-zinc oxide monodisperse antibacterial colloid, characterized in that, The colloid comprises: nano zinc oxide powder, dispersant and water, wherein the total mass ratio of nano zinc oxide powder to dispersant is (1:1)-(10:1), the mass ratio of nano zinc oxide powder to water is (1:100)-(1:10000), and the diameter of the nano zinc oxide particles in the colloid is 60nm-100nm.

2. The small molecule-coated nano-zinc oxide monodisperse antibacterial colloid as described in claim 1, characterized in that, The dispersant is a composite dispersant composed of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, polyethylene glycol, and sodium tripolyphosphate.

3. The small molecule-coated nano-zinc oxide monodisperse antibacterial colloid as described in claim 2, characterized in that, The mass ratio of each component in the composite dispersant is: sodium hexametaphosphate: sodium dodecylbenzenesulfonate: polyethylene glycol: sodium tripolyphosphate = (5-1): (4-1): (3-1):

1.

4. A method for preparing the small molecule-coated nano-zinc oxide monodisperse antibacterial colloid as described in claim 1, characterized in that, Includes the following steps: Place the grinding media into the grinding jar, then add nano zinc oxide powder, dispersant and water, turn on the ball mill and grind for 2-10 hours. Remove the grinding jar and the grinding media to obtain small molecule coated nano zinc oxide monodisperse antibacterial colloid.

5. The preparation method according to claim 4, characterized in that, The mass ratio of the nano zinc oxide powder to the ball milling media is (1:100)-(1:10000); the total mass ratio of the nano zinc oxide powder to the dispersant is (1:1)-(10:1); and the mass ratio of the nano zinc oxide powder to water is (1:100)-(1:10000).

6. The preparation method according to claim 4, characterized in that, The ball milling media are zirconia beads with a particle size of 0.1 mm to 0.5 mm.

7. The preparation method according to claim 4, characterized in that, The ball mill rotates at a speed of 200 r / min to 800 r / min.

8. The preparation method according to claim 4, characterized in that, The ball milling temperature is 20℃-40℃; the pH value of the liquid during ball milling is 9-9.

5.

9. The application of the small molecule-coated nano zinc oxide monodisperse antibacterial colloid as described in claim 1 in antibacterial products.

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