Disclosure of Invention
Therefore, it is desirable to provide a white antibacterial ceramic using copper ions as an antibacterial agent at a low cost and a method for preparing the same.
In order to achieve the above object, a first aspect of the present invention provides a method for preparing a white antibacterial ceramic, comprising the steps of:
preheating the basic ceramic, then putting the basic ceramic into molten copper ion antibacterial molten salt for ion exchange, and cooling to obtain the white antibacterial ceramic;
the copper ion antibacterial molten salt comprises the following components in percentage by mass: CuSO4 40%-80%、Na2SO4 10%-30%、K2SO410% -30%; the ion exchange temperature is 440-560 ℃, and the ion exchange time is 20-60 min;
the composition of the base ceramic comprises: SiO 22、Al2O3、Na2O、K2O、B2O3CaO, ZnO; wherein Na2The content of O in percentage by mass is 0.3-1%; k2The content of O is 0-5% by mass. Preferably, the composition and mass percentage of the base ceramic are SiO2 48%-70%、Al2O3 9%-17%、ZrO2 0-12%、BaO 0-3%、CaO 1-12%、ZnO 0.1-7%、ZrO20-12%、MgO 0-2.5%、P2O5 0%-3.0%、Na2O 0.3-1%、K2O 0-5%。
Preferably, the antibacterial molten salt comprises the following components in percentage by mass: CuSO4 50%-60%、Na2SO4 20%-30%、K2SO420% -30%; the ion exchange time is 20-30 min.
Preferably, the white antibacterial ceramic has a Delta E less than or equal to 1 with the base ceramic before ion exchange.
In a second aspect of the present invention, a white antibacterial ceramic is provided, which is prepared by the preparation method of the first aspect of the present invention; the antibacterial ions in the white antibacterial ceramic are copper ions.
Preferably, the mass percentage content of copper ions in the white antibacterial ceramic is 0.01-0.05%.
Preferably, the mass percentage content of copper ions in the white antibacterial ceramic is 0.01-0.02%.
Preferably, the antibacterial R value of the white antibacterial ceramic is more than 3.
Preferably, the temperature difference of the instant heating resistance of the white antibacterial ceramic is more than or equal to 150 ℃.
Different from the prior art, the technical scheme at least comprises the following beneficial effects: by passing Na over2The content of O in percentage by mass is 0.3-1%; k2The basic white ceramic with the content of 0-5% by mass of O is immersed in the mixed molten salt of copper sulfate, sodium sulfate and potassium sulfate, so that copper ions are obtained on the surface of the ceramic, the wear resistance and the Vickers hardness are enhanced, the ceramic has antibacterial performance, the antibacterial activity value R is more than or equal to 3, and the delta E before and after antibacterial is less than or equal to 1.
Detailed Description
To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.
Examples 1-7 of the invention were prepared by the following method:
1. preparing base ceramics: uniformly mixing the ceramic raw materials in proportion: the water ratio is 1:0.7, the ball milling fineness is 250 meshes, the mixture is sieved and glazed, and the glaze surface is put into a kiln for heat treatment after being dried, the firing temperature is 1150-1300 ℃, and the firing time is 5-8 h.
In each example, three different ceramics were used as base ceramics, respectively:
the base ceramic 1 comprises the following components in percentage by weight: SiO 22 64.17%,Al2O3 14.66%,ZrO2 11.17%,BaO 2.6%,CaO 1.91%,ZnO 1.86%,MgO 0.83%,P2O5 0.85%,Na2O 0.45%,K2O 0.41%,
The base ceramic 2 comprises the following components in percentage by weight: SiO 22 59.08%,Al2O3 16.87%,CaO 11.93%,ZnO 3.02%,MgO 2.21%,P2O5 0.25%,Na2O 0.60%,K2O 4.34%,BaO 1.7%;
Base ceramic 3 (comparative) with a composition of: SiO 22 61.92%,Al2O3 13.68%,Na2O 12.95%,K2O 4.74%,CaO 1.93%,ZnO 3.52%,MgO 1.21%。
2. Preparation of molten salt: mixing CuSO4、Na2SO4、K2SO4Weighing according to the proportion shown in Table 1 and mixing uniformly; the melting point T0 of the antibacterial molten salt with different proportions is shown in Table 1;
placing the uniformly mixed molten salt into an alumina crucible, placing the alumina crucible into a high-temperature furnace, and melting the molten salt within the range of 440-530 ℃ for later use after the molten salt is molten;
3. ion exchange: the basic ceramic is placed in a preheating furnace to be preheated for 30min, the preheating temperature T1 and the molten salt temperature T2 need to be controlled to be T2-T1 less than 100 ℃, the preheated basic ceramic is placed in molten antibacterial molten salt to carry out ion exchange, and the exchange time and the exchange temperature are shown in table 1. And after finishing ion exchange, putting the ceramic into a muffle furnace for rapid cooling to obtain the antibacterial ceramic, cleaning residues on the surface of the antibacterial ceramic by using hot water, and carrying out performance test, wherein test items and results are shown in table 1.
The basic ceramic is firstly tested according to QB/T1503-2011, and then the antibacterial ceramic after ion exchange is tested according to La-b, and delta E is calculated, and the color difference judgment is carried out according to GB/T3532-1995, and the result is shown in Table 1.
Table 1 compositions, processes and performance tables for antibacterial ceramics prepared in examples 1-7
Examples 1-7 test items physical properties the definition and explanation or test methods are as follows:
(1) melting point T0: indicating the temperature of the high-temperature furnace after the mixed molten salt is completely melted;
(2) molten salt temperature T2: setting the temperature of ion exchange, and indicating the temperature of a high-temperature furnace;
(3) cu content: testing by adopting a handheld XRF;
(4)L*a*b*the value: the reflectivity is tested by adopting an Shimadzu UV-2600 ultraviolet spectrophotometer, and the L is obtained by converting the instrument with software' color anyist*Value a*Value b*A value;
(5) delta E: according to QB/T1503 and 2011,
△E=【(△L*)2+(△a*)2+(△b*)2】1/2
(6) antibacterial activity value R: according to the method in JIS Z2081:2010, test bacterial liquid is inoculated on a basic ceramic plate and an antibacterial ceramic plate, the ceramic plate is cultured for 24H in an aseptic plate, the average logarithmic value of the viable count obtained by culturing the ceramic plate for 24H is calculated, and the average logarithmic difference value of the viable count is calculated.
From the data in table 1, it can be seen that the temperature of the molten salt (ion exchange) has a significant effect on the effect of the ion exchange in examples 3 and 4. And the basic ceramic material has high Na and K contents, so that the ion exchange is more, the Cu content in the antibacterial ceramic is too high, the Delta E is more than 1, and the color of the ceramic has color difference.
And (3) wear resistance test:
equipment: an abrasion resistance tester, model A20-339, the revolution range is 0-3000, the fineness of abrasive paper is 150 meshes, and the sample size is phi 35 mm; the working temperature of the drying box is 110 +/-5 ℃; an electronic balance, accurate to 0.0001 g;
the test steps are as follows: weighing m1 before and after the antibacterial test piece, then placing the test piece on a sample table with the surface facing upwards, clamping the test piece by using a metal clamp, installing 150-mesh abrasive paper on a grinding head, enabling the abrasive paper on the grinding head to be in contact with the test piece, simultaneously selecting a load of 500g to be loaded on the grinding head, setting the revolution number of 500, and starting an instrument. Immediately stopping the machine when the grinding is carried out for the set times, taking down the test piece, washing the test piece by flowing water, drying the test piece in a drying box, weighing the test piece by using a balance m2, calculating the mass loss before and after grinding, and observing the surface abrasion condition by using a microscope, wherein the specific figures are shown in figures 1-7.
The vickers hardness and abrasion resistance results for examples 1-7 are shown in table 2,
TABLE 2 comparison of Vickers hardness and abrasion resistance of basic ceramics (before ion exchange) and antibacterial ceramics (after antibacterial)
Vickers hardness number: a Vickers hardness tester, model TMVP-1S, a diamond pressure head, a load of 300g and a load time of 15S.
As can be seen from FIGS. 1 to 7 and Table 2, base ceramic 1 (Na)2O 0.45%,K2O0.41%) and base ceramic 2 (Na)2O 0.60%,K2Na in O4.34%,)2The content of O is less than 1 percent, the Vickers hardness is higher, and the wear-resisting condition is better than that of the basic ceramic 3; and base ceramic 3 (Na)2O 12.95%,K2O4.74%) of Na2The content of O is high, and the component Na in the ceramic is found in research2The content of O is more than 1%, and the thermal expansion coefficient of the ceramic is increasedHigh, thermal stability, chemical stability and mechanical strength are all reduced. Thereby controlling Na in the base ceramic2The content of O in percentage by mass is 0.3-1.0%; k2The content of O in percentage by mass is 0-5%, which is beneficial to controlling the content of copper ions entering the ceramic in the later period to be 0.01-0.05 wt%, when the copper content on the surface of the ceramic is more than 0.01%, the R value is more than 3 with good antibacterial effect, and the appearance of the product is discolored due to the introduction of excessive copper ions into the ceramic.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the number.
It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.