A modified rare earth complex RE@TC and its application in antibacterial ceramic glaze

Abstract

The present invention provides a modified rare earth complex RE@TC and its application in antibacterial ceramic glaze, wherein the modified rare earth complex RE@TC is prepared from modified rare earth chloride RE-FZ and zinc phosphate, and the preparation method of the modified rare earth chloride RE-FZ comprises the following steps: S1: washing humic acid and drying it, then adding sodium hydroxide solution, heating and stirring until dissolved to obtain humic acid solution; S2: adding rare earth chloride to deionized water and stirring and dissolving to obtain rare earth chloride solution, then mixing the humic acid solution and the rare earth chloride solution evenly and standing, standing and drying, grinding the dried solid to obtain modified rare earth chloride RE-FZ. The glaze prepared from the modified rare earth complex RE@TC of the present invention forms a coating with antibacterial effect on the surface of the ceramic cup, and finally makes the ceramic product have stable and efficient antibacterial function.

Description

Technical Field

[0001] The invention belongs to the field of ceramic glazes, and in particular relates to a modified rare earth complex RE@TC and application thereof in antibacterial ceramic glazes. Background Art

[0002] In modern society, people's pursuit of daily necessities is gradually inclined towards functionality, among which antibacterial products are gradually favored by consumers. The characteristics of this type of product are that its surface has the function of killing or inhibiting the growth of microorganisms. At present, there are many types of utensils used for daily drinking water. If distinguished by material, common ones are stainless steel, glass, plastic, ceramics, etc. Among them, the raw material of ceramic materials is soil, so the process of preparing ceramic cups will not waste natural resources. At the same time, it has the characteristics of being non-toxic and harmless, stable in nature, and not easy to corrode. In the process of making ceramic cups, the purpose of antibacterial and health care can be achieved by brushing glaze with directional functions, which can better meet the requirements of people's drinking vessels in the market.

[0003] Escherichia coli and Staphylococcus aureus are the two most typical pathogenic microorganisms. Escherichia coli includes pathogenic strains that cause a variety of human diseases, directly or indirectly causing more than 2 million deaths each year. There are six types of enteric pathogens of Escherichia coli, including Shiga toxin-producing Escherichia coli (STEC), enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), enteroaggregative Escherichia coli (EAEC), diffusely adherent Escherichia coli (DAEC) and enteroinvasive Escherichia coli (EIEC). These strains can cause gastrointestinal diseases such as diarrhea in humans. At the same time, some strains of Escherichia coli can also cause extraintestinal diseases, which are called extraintestinal pathogenic Escherichia coli (exic). Staphylococcus aureus is one of the most notorious human pathogens, causing diseases ranging from minor skin and wound infections to fatal sepsis or multiple organ failure. During the infection process, Staphylococcus aureus can induce cell apoptosis through various pathways. Staphylococcus aureus is a common foodborne pathogen that is widely present in the natural environment. Food poisoning caused by Staphylococcus aureus accounts for about 25% of foodborne microbial food poisoning incidents. Studies have shown that rare earth ions can inhibit or kill microorganisms by destroying the bacterial structure of microbial cells, such as cell walls, cell membranes, cell nuclei, mitochondria, and ribosomes, cross-linking DNA molecules, making them unable to unwind and replicate, and inhibiting the synthesis of multiple enzymes in cells, causing them to lose catalytic activity. 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 complex RE@TC and its application in antibacterial ceramic glaze.

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

[0006] In a first aspect, the present invention provides a modified rare earth complex RE@TC, wherein the modified rare earth complex RE@TC is prepared from a modified rare earth chloride RE-FZ and zinc phosphate, and the preparation method of the modified rare earth chloride RE-FZ comprises the following steps:

[0007] S1: washing and drying the humic acid, then adding sodium hydroxide solution, heating and stirring until dissolved to obtain a humic acid solution;

[0008] S2: adding rare earth chloride to deionized water and stirring to dissolve to obtain rare earth chloride solution, then mixing the humic acid solution and the rare earth chloride solution evenly and letting them stand, and then drying them in an oven at 75°C-90°C, and grinding the dried solid to obtain modified rare earth chloride RE-FZ.

[0009] Preferably, the mass ratio of humic acid to rare earth chloride is (1-1.5):(3-5).

[0010] Preferably, the mass concentration of the sodium hydroxide solution is 1.0%-1.5%.

[0011] Preferably, the rare earth chloride is one of lanthanum chloride hexahydrate, cerium chloride hexahydrate, and yttrium chloride hexahydrate, or a mixture of several of them.

[0012] Preferably, the preparation method of the modified rare earth complex RE@TC is:

[0013] Ammonia water is added to deionized water to prepare an ammonia solution, and then the modified rare earth complex RE@TC and zinc phosphate are added in sequence, stirred until they are completely dissolved, and then dried to a powder state, and then transferred to a muffle furnace for calcination. After calcination, the rare earth complex RE@TC is obtained by grinding, wet sand milling, drying, and then grinding again.

[0014] Preferably, the mass ratio of the modified rare earth complex RE@TC to zinc phosphate is (1.5-2.5): (0.5-1.0).

[0015] Preferably, the mass concentration of the aqueous ammonia solution is 8%-12%.

[0016] Preferably, the drying conditions are: drying at 50-60° C. for 24-36 h.

[0017] Preferably, the calcination conditions are: calcination at 1100-1300° C. for 3-4.5 h.

[0018] Preferably, the sand milling condition is sand milling in a sand mill at 2800-3500 r / min for 1.5-2.5 h.

[0019] Preferably, the average particle size of the rare earth complex RE@TC is 120-140 nm.

[0020] In a second aspect, the present invention also provides the use of the modified rare earth complex RE@TC in antibacterial ceramic glaze.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The rare earth material used in the modified rare earth complex RE@TC prepared by the present invention is rare earth chloride modified by humic acid. Compared with the use of rare earth chloride alone, the material synthesized by the modified rare earth chloride and zinc phosphate (humic acid containing rare earth ions) has a better antibacterial effect, because the addition of rare earth elements changes the surface properties of sodium humate, making it more adsorbable to bacteria, so more bacteria can be adsorbed on the surface of sodium humate, thereby increasing the antibacterial effect. Secondly, rare earth elements themselves have the ability to chelate with metal ions. When they are combined with sodium humate, they may promote the chelation reaction between sodium humate and metal ions on the bacterial cell wall or cell membrane, thereby destroying the normal physiological function of bacteria. Finally, the addition of rare earth elements will also promote sodium humate to release more oxidizing substances under specific conditions. These oxidizing substances can more effectively destroy the redox balance in bacterial cells, leading to bacterial death. Therefore, the combination of rare earth elements and humic acid can play a significant synergistic antibacterial effect.

[0023] (2) In the present invention, the modified rare earth complex RE@TC is added to the glaze on the surface of the ceramic cup instead of the green body, so that the functional material can better contact with the liquid in the ceramic cup and thus exert its effect. The average particle size of the modified rare earth complex RE@TC in the glaze is less than 140 nm, which is a nano-scale material and has strong dispersibility. The antibacterial ceramic cup prepared in this way has a more stable function. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a graph showing the antibacterial effect of antibacterial ceramic cups containing different rare earth complexes (RE@TC) on Escherichia coli;

[0025] Figure 2 This is a diagram showing the antibacterial effect of antibacterial ceramic cups containing different rare earth complexes (RE@TC) on Staphylococcus aureus. DETAILED DESCRIPTION

[0026] 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.

[0027] The present invention will be described in detail below with reference to the embodiments.

[0028] Example 1

[0029] (1) Preparation of rare earth chlorides (RE-FZ) after different modifications

[0030] The modification methods of rare earth chlorides were prepared according to the following steps: 50 g of humic acid was weighed into a beaker, and deionized water was added to wash repeatedly until the supernatant was clear, and then placed in an oven at 80°C for 12 h for drying. Then the dried humic acid was added to 200 mL of 1.0% sodium hydroxide solution, and the beaker was placed in a magnetic heating stirrer at 600 r / min, 1 h, 80°C, until fully dissolved. Then, 100 g of cerium chloride hexahydrate, 150 g of lanthanum chloride hexahydrate, and 250 g of yttrium chloride hexahydrate were added to different beakers, and 800 mL of deionized water was added to stir and dissolve, and then a 1 L volumetric flask was used to make up the volume. The concentration of the three rare earth chloride solutions was 1 mol / L. 200 mL of humic acid solution was weighed and mixed with 200 mL of different rare earth chloride solutions, respectively. The mixture was placed in an oven and dried at 80°C for 24 h. The obtained solid was ground in a mortar. The three modified rare earth chloride materials were named Ce-FZ, La-FZ, and Y-FZ, respectively.

[0031] (2) Preparation of different rare earth complexes (RE@TC)

[0032] Take an appropriate amount of ammonia water and add it to three beakers. Then, prepare a 10% ammonia solution with deionized water, add the modified rare earth chloride (La-FZ) prepared in step (1) at a mass ratio of 3:2, add the modified rare earth chloride (Ce-FZ) prepared in step (1) at a mass ratio of 3:1, and add the modified rare earth chloride (Y-FZ) prepared in step (1) and zinc phosphate at a mass ratio of 5:1. Then, stir the two powder materials in the three beakers until they are completely dissolved in water, pour them into an evaporating dish, place the evaporating dish in an oven at 55°C for 24 hours until it becomes a powder. After transferring the obtained solid into a crucible, place it in a muffle furnace for calcination at a calcination temperature of 1200°C for 4 hours. After calcination, grind the powder into fine powder using a grinder and transfer it into a beaker. After adding deionized water according to a solid / liquid configuration of 25%, use a sand mill for wet sand grinding. The speed of the sand mill is 3000. r / min, the sand grinding time was 2 h, and finally a nano RE@TC slurry with a Dv(90) of 120-140 nm was obtained. The sand-milled slurry was then transferred into a vacuum drying oven, the pressure was set to 0.01 MPa, the temperature was set to 80 °C, and the drying time was 24 h. The obtained powder was ground again using a grinder, and the obtained powder materials were the required different types of modified rare earth complexes (named Ce@TC, La@TC, and Y@TC, respectively).

[0033] Comparative Example 1

[0034] The modified rare earth chloride in Example 1 was replaced with unmodified rare earth chloride, and the remaining steps were carried out according to Example 1.

[0035] Comparative Example 2

[0036] In the preparation process of the modified rare earth complex in Example 1, the mass ratio of the modified rare earth chloride (La-FZ) to zinc phosphate was 1:1, and the remaining steps were carried out according to Example 1. The prepared modified rare earth complex was named La@TC-1.

[0037] Comparative Example 3

[0038] In the preparation process of the modified rare earth complex in Example 1, the mass ratio of the modified rare earth chloride (La-FZ) to zinc phosphate was 10:1, and the remaining steps were carried out according to Example 1. The prepared modified rare earth complex was named La@TC-2.

[0039] Comparative Example 4

[0040] The mass of lanthanum chloride hexahydrate in the preparation process of the modified rare earth chloride in Example 1 is 500 g, and the remaining steps are carried out according to Example 1. The prepared modified rare earth complex is named La@TC-3.

[0041] Comparative Example 5

[0042] The mass of lanthanum chloride hexahydrate in the preparation process of the modified rare earth chloride in Example 1 is 83 g, and the remaining steps are carried out according to Example 1. The prepared modified rare earth complex is named La@TC-4.

[0043] Application Example Preparation of antibacterial glaze containing different rare earth complexes (RE@TC)

[0044] Quartz, feldspar, and clay were respectively mixed with the modified rare earth complex (RE@TC prepared in Example 1) in a ratio of 5:10:7:1, and then diluted with deionized water to a concentration of 55% to obtain a rare earth antibacterial glaze water for use. The antibacterial materials prepared in Comparative Example 1 were named La@TC, Y@TC, and Ce@TC.

[0045] Comparative Application Examples

[0046] The different modified rare earth complexes (RE@TC) in the application examples were replaced with the rare earth complex samples prepared in comparative examples 1-5, and the remaining steps were carried out according to the application examples. According to the different rare earth elements in the rare earth complex control sample (RE@TC), the antibacterial materials prepared by comparative example 1 were named CK-La@TC, CK-Ce@TC, and CK-Y@TC. The antibacterial materials prepared by comparative examples 2-5 were named La@TC-1, La@TC-2, La@TC-3, and La@TC-4.

[0047] Experimental Example 1 Testing the anti-E. coli performance of rare earth ceramic cups containing different antibacterial glazes

[0048] The 11 different antibacterial glazes were sent to a ceramic manufacturer to prepare 11 different rare earth modified antibacterial ceramic cups. The following method was used to detect the 11 ceramic cups: Escherichia coli was activated with LB medium to a concentration of about 1×10 9cfu / mL, then draw 0.3 mL and drop it on the bottom of different types of antibacterial ceramic cups, and evenly cover the bacterial solution with a 40mm (length) × 40mm (width) × 10mm (thickness) sterile polyethylene film to ensure that there are no pores on the film, and then transfer the ceramic cup to the incubator at 37°C for 24 h. After incubation, take out the film, and repeatedly rinse the film with 10 mL of 0.9% NaCl solution with a pH of 7.0-7.2 as the eluent. Finally, dilute the eluent 10 times with deionized water, draw 1 mL each into a blank culture dish, pour in 20 mL of LB agar medium that has been sterilized and cooled to 55°C, shake evenly, and place in an incubator set to 37°C for 24h. After the incubation, count the colonies on the LB solid culture medium. The control group is 0.3 mL of Escherichia coli culture after 24 h incubation in the incubator at 37°C, and then pour the counted LB solid culture medium after mixing with 10 mL of eluent. The inhibition rate of E. coli = the number of colonies in the experimental group / the number of colonies in the control group. Figure 1 As shown in the figure, the first column from left to right is the blank control group, CK-La@TC, CK-Y@TC, CK-Ce@TC, the second column from left to right is La@TC-1, La@TC-2, La@TC-3, La@TC-4, and the third column from left to right is the antibacterial effect diagram of La@TC, Y@TC, Ce@TC on Escherichia coli. Among them, the antibacterial rate of Ce@TC on Escherichia coli is higher than 99.99%.

[0049] Experimental Example 2 Testing the anti-Staphylococcus aureus performance of rare earth ceramic cups containing different antibacterial glazes

[0050] The microorganism used in this experiment was replaced with Staphylococcus aureus, and the remaining experimental steps and the calculation method of the antibacterial rate were carried out according to Experimental Example 1. The antibacterial rate of Staphylococcus aureus = the number of colonies in the experimental group / the number of colonies in the control group. Figure 2 As shown, the order of pictures is Figure 1 Similarly, it can be seen that the inhibition rates of La@TC, Y@TC and Ce@TC against Staphylococcus aureus are all above 99.99%.

[0051] 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 complex RE@TC, characterized in that: The modified rare earth complex RE@TC is prepared from modified rare earth chloride RE-FZ and zinc phosphate. The preparation method of the modified rare earth chloride RE-FZ comprises the following steps: S1: washing and drying the humic acid, then adding sodium hydroxide solution, heating and stirring until dissolved to obtain a humic acid solution; S2: adding rare earth chloride to deionized water and stirring to dissolve to obtain a rare earth chloride solution, then mixing the humic acid solution and the rare earth chloride solution evenly and letting them stand, drying after standing, and grinding the dried solid to obtain a modified rare earth chloride RE-FZ; The mass ratio of humic acid to rare earth chloride is (1-1.5): (3-5); The preparation method of the modified rare earth complex RE@TC is: Ammonia water is added to deionized water to prepare an ammonia solution, and then modified rare earth chloride RE-FZ and zinc phosphate are added in sequence, stirred until they are completely dissolved, dried to a powder state, and transferred to a muffle furnace for calcination. After calcination, the modified rare earth complex RE@TC is obtained by grinding, wet sand milling, drying, and then grinding again; The mass ratio of the modified rare earth chloride RE-FZ to zinc phosphate is (1.5-2.5): (0.5-1.0); The drying conditions are: drying at 50-60°C for 24-36 h; the calcining conditions are: calcining at 1100-1300°C for 3-4.5 h; the sand milling conditions are sand milling in a sand mill at 2800-3500 r / min for 1.5-2.5 h.

2. The modified rare earth complex RE@TC according to claim 1, characterized in that: The mass concentration of the sodium hydroxide solution is 1.0%-1.5%.

3. The modified rare earth complex RE@TC according to claim 1, characterized in that: The rare earth chloride is one of lanthanum chloride hexahydrate, cerium chloride hexahydrate, and yttrium chloride hexahydrate, or a mixture of several of them.

4. The modified rare earth complex RE@TC according to claim 1, characterized in that: The mass concentration of the ammonia solution is 8%-12%.

5. The modified rare earth complex RE@TC according to claim 1, characterized in that: The average particle size of the modified rare earth complex RE@TC is 120-140 nm.

6. Use of the modified rare earth complex RE@TC according to any one of claims 1 to 5 in antibacterial ceramic glaze.

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