A modified rare earth antibacterial glaze and preparation method thereof

Abstract

The present invention provides a modified rare earth antibacterial glaze and a preparation method thereof, wherein the modified rare earth antibacterial glaze is made of the following raw materials in parts by weight: 3-5 parts of quartz, 9-11 parts of feldspar, 4-6 parts of clay, and 1-2 parts of a modified rare earth complex. The modified rare earth antibacterial glaze of the present invention uses a modified rare earth complex and has good killing or inhibition capabilities for microorganisms remaining in ceramic products during daily use.

Description

Technical Field

[0001] The invention belongs to the field of antibacterial, and in particular relates to a modified rare earth antibacterial glaze and a preparation method thereof. Background Art

[0002] With the development of economy, people's requirements for quality of life have also increased. The most important manifestation is that people pay more and more attention to the functionality of daily necessities in life, rather than other factors such as appearance. Among them, the antibacterial function of daily necessities has received widespread attention. Among these daily necessities, antibacterial ceramic cups are currently a hot topic of research, because they can be in close contact with drinking water entering the human body and are closely related to human health. Ordinary ceramic cups with general antibacterial properties are prone to retain some microorganisms that are pathogenic to the human body. These microorganisms are mainly Escherichia coli and Staphylococcus aureus. Therefore, antibacterial ceramic cups can kill or inhibit the above two microorganisms, which can have a positive impact on human health. Under normal circumstances, Escherichia coli will not cause any harm to our health and has a symbiotic relationship with the human body. However, as the living environment of Escherichia coli changes, such as entering other organs, it will destroy the microecological balance of the "invaded" organ, thus causing local infection. In severe cases, it can cause systemic disseminated infection and even endanger life. At present, Escherichia coli has been classified into five typical bacterial genera that are harmful to humans, such as enterotoxigenic Escherichia coli. Staphylococcus aureus is also a typical animal pathogen that can cause a variety of infectious diseases in humans, such as bacteremia, endocarditis, sepsis, and septic shock syndrome.

[0003] The ability of rare earth elements to kill or inhibit microorganisms has long been widely verified, especially for Escherichia coli and Staphylococcus aureus, which are widely pathogenic bacteria. On this basis, rare earth nanomaterials further enhance their antibacterial effects through small molecule effects. The antibacterial mechanisms of rare earth nanomaterials are mainly oxidative stress, ion release, and contact antibacterial. In addition, rare earth nanoparticles can also combine nanoparticles with bacterial cell membranes through electrostatic interactions, thereby affecting the transport and exchange of nutrients between bacteria and cell fluids and inhibiting bacterial growth. In addition to rare earths, zinc oxide is also a typical antibacterial material, which can kill or inhibit microorganisms through mechanisms such as ion dissolution, inhibition of bacterial metabolism, photocatalysis, and electron transfer. In addition, studies have shown that rare earth lanthanum-zinc oxide complexes can produce synergistic effects and further enhance the antibacterial effect. At the same time, although rare earth cerium-zinc oxide composites also have good antibacterial properties, due to the frequent changes in rare earth prices in the international market, it is also necessary to find a more cost-effective rare earth compound to ensure the possibility of future scale-up production. Summary of the invention

[0004] In view of this, the present invention aims to overcome the defects in the prior art and proposes a modified rare earth antibacterial glaze and a preparation method thereof.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A modified rare earth antibacterial glaze, the glaze is made of the following raw materials in parts by weight: 3-5 parts of quartz, 9-11 parts of feldspar, 4-6 parts of clay, and 1-2 parts of a modified rare earth complex;

[0007] The modified rare earth complex is prepared by a method comprising the following steps: adding ammonia water, anhydrous ethanol, modified rare earth nitrate and zinc oxide into deionized water, uniformly mixing to obtain a mixed solution, drying the mixed solution to obtain a solid sample, calcining, grinding and sand-milling the solid sample to obtain a nano-slurry, and drying and grinding the nano-slurry to obtain the modified rare earth complex.

[0008] Furthermore, the solid-liquid ratio of the ammonia water, anhydrous ethanol, modified rare earth nitrate, zinc oxide and deionized water is 4-6:4-6:4-5:1-2:23-25; and the mass concentration of the ammonia water is 25-28%.

[0009] Furthermore, the temperature of the drying step is 80-150°C and the time is 12-18 hours; the temperature of the calcining step is 1200-1450°C and the time is 3-4.5 hours; the sand milling rate is 2500-3500 r / min and the time is 3-4 hours; and the particle size of the modified rare earth complex is 80-100 nm.

[0010] Furthermore, the modified rare earth nitrate is prepared by a method comprising the following steps:

[0011] Step 1 is to add rare earth nitrate into deionized water and dissolve it to obtain a rare earth nitrate solution;

[0012] Step 2 is adding chitosan into the citric acid solution and dissolving the chitosan to obtain a chitosan solution;

[0013] Step 3 is to mix the chitosan solution with the rare earth nitrate solution, adjust the pH value of the solution, and then add sodium bicarbonate solution thereto. After the reaction is completed, the precipitated white precipitate is filtered, washed, dried, and ground to obtain the modified rare earth nitrate.

[0014] Furthermore, the concentration of the rare earth nitrate solution in step 1 is 0.5-0.7 mol / L; the mass concentration of the citric acid solution in step 2 is 0.7-1.5%; and the solid-liquid ratio of chitosan to citric acid solution in step 2 is 1-1.5 g:40-45 mL.

[0015] Furthermore, the rare earth nitrate is at least one of cerium, lanthanum or yttrium nitrate.

[0016] Furthermore, the volume ratio of the chitosan solution, the rare earth nitrate solution and the sodium bicarbonate solution in step 3 is 3.5-4.5:0.5-1.5:2.0-3.0; and the mass concentration of the sodium bicarbonate solution in step 3 is 30-40%.

[0017] Furthermore, the pH value in step 3 is 6.5-7.5; the temperature of the drying step in step 3 is 80-120° C., and the time is 10-15 hours.

[0018] The preparation method of the modified rare earth antibacterial glaze comprises the following steps: adding quartz, feldspar, clay and modified rare earth complex into 1.5-2.0 times the amount of deionized water, and mixing them evenly to obtain the modified rare earth antibacterial glaze.

[0019] The modified rare earth nitrate can use chitosan as a carrier to provide a stable spatial structure for rare earth ions with antibacterial efficacy, encapsulate the rare earth ions, and make the material structure more stable. Chitosan itself has the property of penetrating cell membranes and entering cells. After carrying rare earth ions with antibacterial efficacy, the rare earth ions can enter cells and inhibit the secretion of intracellular enzymes through the catalytic effect of the rare earth ions. The chitosan that enters the cells can chelate some metal ions that promote the growth and reproduction of bacteria. The two interact with each other, thereby more effectively inhibiting the reproduction of microorganisms.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The modified rare earth nitrate of the present invention can more efficiently penetrate the cell membrane on the surface of microorganisms through the electrostatic effect of chitosan, and after entering the cell, the chelation effect of chitosan and the catalytic effect of rare earth ions are used to synergistically resist bacteria, ultimately playing a significant inhibitory effect on Escherichia coli and Staphylococcus aureus.

[0022] The modified rare earth complex described in the present invention is a nano-scale material. The modified rare earth nitrate is compounded with zinc oxide, which not only has the special small-size antibacterial effect of nanomaterials, but also is more likely to cause changes in membrane permeability and lysis, and ultimately can have a very outstanding effect on inhibiting microorganisms.

[0023] The modified rare earth antibacterial glaze of the present invention adopts a modified rare earth complex and has good killing or inhibiting ability to the microorganisms remaining in the daily use of ceramic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze on Escherichia coli described in Example 1 of the present invention;

[0025] Figure 2 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze on Escherichia coli described in Example 2 of the present invention;

[0026] Figure 3 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze on Escherichia coli described in Example 3 of the present invention;

[0027] Figure 4 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze on Escherichia coli described in Comparative Example 1 of the present invention;

[0028] Figure 5 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze on Escherichia coli described in Comparative Example 2 of the present invention;

[0029] Figure 6 is a blank control diagram of the Escherichia coli of the present invention;

[0030] Figure 7 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze described in Example 1 of the present invention on Staphylococcus aureus;

[0031] Figure 8 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze described in Example 2 of the present invention on Staphylococcus aureus;

[0032] Fig. 9 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze described in Example 3 of the present invention on Staphylococcus aureus;

[0033] Fig.10 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze described in Comparative Example 1 of the present invention on Staphylococcus aureus;

[0034] Fig.11 This is a diagram showing the antibacterial effect of the modified rare earth antibacterial glaze described in Comparative Example 2 of the present invention on Staphylococcus aureus;

[0035] Fig.12 It is a blank control diagram of the Staphylococcus aureus described in the present invention. DETAILED DESCRIPTION

[0036] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0037] The present invention will be described in detail below with reference to the embodiments.

[0038] Example 1

[0039] A method for preparing a modified rare earth antibacterial glaze comprises the following steps:

[0040] (1) Add lanthanum nitrate hexahydrate to deionized water to obtain a 0.6 mol / L rare earth nitrate solution after dissolution, add 5 g of chitosan to 200 mL of 1% citric acid solution to obtain the chitosan solution after dissolution, mix 200 mL of the chitosan solution with 50 mL of the rare earth nitrate solution, adjust the pH value of the solution to about 7.0 with 5% ammonia water, and then add 100 mL of 35% sodium bicarbonate solution thereto. After the reaction is completed, filter the precipitated white precipitate, rinse it 3 times, dry it at 80°C for 12 h, and grind it to obtain the modified rare earth nitrate La-CHI;

[0041] (2) 10 mL of ammonia water, 10 mL of anhydrous ethanol, 10 g of modified rare earth nitrate and 2 g of zinc oxide were added to 50 mL of deionized water, and the mixture was uniformly mixed to obtain a mixed solution. The mixed solution was dried at 150°C for 18 hours to obtain a solid sample. The solid sample was calcined at 1400°C for 5 hours, and then ground once, and sand-milled at 3000 r / min for 4 hours to obtain a nano-slurry with a Dv(90) of 80-100 nm. The nano-slurry was dried at 0.01 MPa and 80°C for 24 hours, and ground again to obtain the modified rare earth complex La@YH.

[0042] (3) Add quartz, feldspar, clay and modified rare earth complex in a mass ratio of 4:10:5:1 to twice the amount of deionized water, mix well and obtain the modified rare earth antibacterial glaze.

[0043] Example 2

[0044] The only difference from Example 1 is that the rare earth nitrate is cerium nitrate hexahydrate.

[0045] Example 3

[0046] The only difference from Example 1 is that the rare earth nitrate is yttrium nitrate hexahydrate.

[0047] Comparative Example 1

[0048] A method for preparing a rare earth antibacterial glaze comprises the following steps:

[0049] (1) 10 mL of ammonia water, 10 mL of anhydrous ethanol, 10 g of modified rare earth nitrate and 2 g of zinc oxide were added to 50 mL of deionized water, and the mixture was uniformly mixed to obtain a mixed solution. The mixed solution was dried at 150°C for 18 hours to obtain a solid sample. The solid sample was calcined at 1400°C for 5 hours, and then ground once, sand-milled at 3000 r / min for 4 hours to obtain a nano-slurry with a Dv(90) of 80-100 nm. The nano-slurry was dried at 0.01 MPa and 80°C for 24 hours, and ground again to obtain the modified rare earth complex La@YH.

[0050] (2) Add quartz, feldspar, clay and modified rare earth complex in a mass ratio of 4:10:5:1 to twice the amount of deionized water, mix well and obtain the rare earth antibacterial glaze.

[0051] Comparative Example 2

[0052] A method for preparing a modified rare earth antibacterial glaze comprises the following steps:

[0053] (1) Add lanthanum nitrate hexahydrate to deionized water to obtain a 0.6 mol / L rare earth nitrate solution after dissolution, add 5 g of chitosan to 200 mL of 1% citric acid solution to obtain the chitosan solution after dissolution, mix 200 mL of the chitosan solution with 50 mL of the rare earth nitrate solution, adjust the pH value of the solution to about 7.0 with 5% ammonia water, and then add 100 mL of 35% sodium bicarbonate solution thereto. After the reaction is completed, filter the precipitated white precipitate, rinse it 3 times, dry it at 80°C for 12 h, and grind it to obtain the modified rare earth nitrate La-CHI;

[0054] (2) Add quartz, feldspar, clay and modified rare earth nitrate in a mass ratio of 4:10:5:1 to twice the amount of deionized water, mix well and obtain the modified rare earth antibacterial glaze.

[0055] The anti-Escherichia coli and Staphylococcus aureus performance of the rare earth ceramic cups made of the glaze products prepared in Examples 1-3 and Comparative Examples 1-2 was tested, and the specific method was as follows:

[0056] Use LB medium to activate Escherichia coli and Staphylococcus aureus to 1×10 9cfu / mL, 0.3 mL was drawn and dropped on the bottom of the antibacterial ceramic cup containing different rare earth complexes ((RE@YH)), and the bacterial solution was evenly covered with a 40mm (length) × 40mm (width) × 10mm (thickness) sterile polyethylene film. After there were no pores on the surface of the film, the ceramic cup was transferred to an incubator at 37°C for 24 h. Then the film was taken out and repeatedly rinsed with 10 mL of 0.9% NaCl solution with a pH of 7.0-7.2 as an eluent. Finally, the eluent was diluted 10 and 100 times with PBS buffer, and 1 mL was drawn into each blank culture dish, and then 20 mL of LB agar medium that was sterilized and cooled to 58°C was poured into it, and it was shaken evenly and placed in an incubator at 37°C for 24 h. After the culture was completed, the colonies were counted. The control group was 0.3 mL of Escherichia coli and Staphylococcus aureus culture solution after 24 h of culture at 37°C in the incubator, mixed with 10 mL of the eluate and poured onto the LB solid medium plate for counting. The inhibition rate = the number of colonies in the experimental group / the number of colonies in the control group.

[0057] like Figure 1-12 As shown, the ceramic cup prepared by the glaze in Example 1 has an antibacterial rate of more than 99.99% against Escherichia coli and Staphylococcus aureus. The ceramic cups prepared by the glaze in Example 2 and Example 3 also have an antibacterial rate of more than 99.99% against Staphylococcus aureus, but the antibacterial rate against Escherichia coli is less than 99%. The antibacterial rate of the ceramic cup prepared by the glaze in Comparative Example 1 against Escherichia coli and Staphylococcus aureus is less than 97%. It can be seen that the ceramic cup prepared by the antibacterial glaze obtained by the rare earth nitrate after the chitosan modification lacks the ability to efficiently penetrate the cell membrane, so the antibacterial ability is lower than the antibacterial ceramic cup prepared by the glaze in Example 1. The ceramic cup prepared by the glaze in Comparative Example 2 has an antibacterial rate against Escherichia coli and Staphylococcus aureus lower than 97%. It can be seen that zinc oxide is not added during the preparation of the glaze, and the rare earth in the obtained glaze cannot react synergistically with zinc oxide to enhance the antibacterial ability. Therefore, the antibacterial ability of the ceramic cup prepared by the glaze is lower than that of the antibacterial ceramic cup prepared by the glaze in Example 1.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A modified rare earth antibacterial glaze, characterized in that: The glaze comprises the following raw materials in parts by weight: 3-5 parts of quartz, 9-11 parts of feldspar, 4-6 parts of clay, and 1-2 parts of modified rare earth complex; The preparation method of the modified rare earth complex comprises the following steps: adding ammonia water, anhydrous ethanol, modified rare earth nitrate and zinc oxide to deionized water, uniformly mixing to obtain a mixed solution, drying the mixed solution to obtain a solid sample, calcining, grinding and sand-milling the solid sample to obtain a nano-slurry, and drying and grinding the nano-slurry to obtain the modified rare earth complex; The solid-liquid ratio of the ammonia water, anhydrous ethanol, modified rare earth nitrate, zinc oxide and deionized water is 4-6:4-6:4-5:1-2:23-25; the mass concentration of the ammonia water is 25-28%; the sand milling speed is 2500-3500 r / min, and the time is 3-4 hours; The preparation method of the modified rare earth nitrate comprises the following steps: Step 1 is to add rare earth nitrate into deionized water and dissolve it to obtain a rare earth nitrate solution; Step 2 is adding chitosan into the citric acid solution and dissolving the chitosan to obtain a chitosan solution; Step 3 is to mix the chitosan solution with the rare earth nitrate solution, adjust the pH value of the solution, and then add sodium bicarbonate solution thereto. After the reaction is completed, the precipitated white precipitate is filtered, washed, dried, and ground to obtain the modified rare earth nitrate.

2. The modified rare earth antibacterial glaze according to claim 1, characterized in that: The temperature of the drying step is 80-150°C and the time is 12-18 hours; the temperature of the calcination step is 1200-1450°C and the time is 3-4.5 hours; the particle size of the modified rare earth complex is 80-100 nm.

3. The modified rare earth antibacterial glaze according to claim 1, characterized in that: The concentration of the rare earth nitrate solution in step 1 is 0.5-0.7 mol / L; the mass concentration of the citric acid solution in step 2 is 0.7-1.5%; the solid-liquid ratio of chitosan to citric acid solution in step 2 is 1-1.5 g:40-45 mL.

4. The modified rare earth antibacterial glaze according to claim 1, characterized in that: The rare earth nitrate is at least one of cerium, lanthanum or yttrium nitrate.

5. The modified rare earth antibacterial glaze according to claim 1, characterized in that: The volume ratio of the chitosan solution, the rare earth nitrate solution and the sodium bicarbonate solution in step 3 is 3.5-4.5:0.5-1.5:2.0-3.0; the mass concentration of the sodium bicarbonate solution in step 3 is 30-40%.

6. The modified rare earth antibacterial glaze according to claim 1, characterized in that: The pH value in step 3 is 6.5-7.5; the temperature of the drying step in step 3 is 80-120° C. and the time is 10-15 hours.

7. The method for preparing the modified rare earth antibacterial glaze according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: adding quartz, feldspar, clay and modified rare earth complex into 1.5-2.0 times amount of deionized water, and mixing them evenly to obtain the modified rare earth antibacterial glaze.

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