Preparation method and application of zirconium oxide biological ceramic

Abstract

The invention belongs to the technical field of zirconium oxide biological ceramics, and particularly relates to a preparation method and application of zirconium oxide biological ceramics. The preparation method comprises the following steps: firstly, preparing porous hydroxyapatite of which the pore surface is loaded with silver nitrate, then preparing polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and then preparing a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide compound; then mixing the polycaprolactone coated silver nitrate loaded porous hydroxyapatite / zirconium oxide compound with an auxiliary agent, homogenizing to obtain uniform slurry, performing injection molding on the slurry to obtain a ceramic green body, finally putting the ceramic green body into a sintering furnace, performing programmed heating and heat preservation, and naturally cooling to room temperature to obtain the zirconium oxide biological ceramic. The zirconium oxide biological ceramic obtained by the invention combines good biological activity of hydroxyapatite and excellent mechanical properties of zirconium oxide, is not easy to wear, scratch and the like, and can maintain the form and function of a ceramic ferrule for a long time.

Description

Technical Field

[0001] The present invention belongs to the technical field of zirconium oxide bioceramics, and in particular relates to a preparation method and application of zirconium oxide bioceramics. Background Art

[0002] Antibacterial bioceramic ferrules have broad application prospects, mainly reflected in the following aspects:

[0003] (1) Fiber optic communication field

[0004] With the development of 5G and even future 6G communication technologies, the requirements for the stability and reliability of optical fiber communications are becoming increasingly stringent. Antimicrobial bioceramic ferrules not only ensure high-precision optical fiber connections and stable signal transmission, but their antimicrobial properties also reduce damage to optical fibers and equipment caused by bacterial growth, extending equipment life and reducing maintenance costs. Demand for these ferrules is expected to increase in scenarios such as communication base stations and data centers.

[0005] (2) Medical field

[0006] In medical fiber optic devices such as endoscopes and laser therapy equipment, antimicrobial bioceramic ferrules can reduce the risk of bacterial infection and ensure patient safety. Furthermore, in some implantable medical devices, the use of antimicrobial bioceramic ferrules as connectors can reduce bacterial adhesion and biofilm formation, lowering the probability of postoperative infection and improving the safety and reliability of the medical devices.

[0007] (3) Food, beverage and pharmaceutical industries

[0008] In the production workshops of the food, beverage and pharmaceutical industries, the use of antibacterial bio-ceramic ferrules in fiber optic detection and monitoring equipment can prevent bacteria from contaminating the production environment and products, meet strict hygiene standards and quality requirements, and help ensure food safety and drug quality.

[0009] (4) Smart home and Internet of Things

[0010] The fiber optic connection components in smart homes and IoT devices use antibacterial bio-ceramic ferrules, which can stay clean during long-term use, reduce equipment failures caused by bacterial growth, improve the stability and reliability of the entire smart home system, and provide people with a healthier and more comfortable living environment.

[0011] However, existing zirconia bioceramics have problems such as high density, poor antibacterial properties and large tolerance before and after sintering. Therefore, there is an urgent need to develop a bioceramic with low density, strong antibacterial persistence and small tolerance before and after sintering. Summary of the Invention

[0012] The purpose of the present invention is to provide a preparation method and application of zirconium oxide bioceramics.

[0013] The implementation process of the present invention is as follows:

[0014] A method for preparing a zirconium oxide bioceramic comprises the following steps:

[0015] (1) Porous hydroxyapatite and sodium carboxymethyl cellulose are added to a silver nitrate solution, stirred for adsorption reaction, filtered, and vacuum-dried to obtain porous hydroxyapatite with silver nitrate loaded on the pore surface, which is recorded as AgNO3 / porous hydroxyapatite;

[0016] (2) Polycaprolactone was dissolved in ethyl acetate, and then porous hydroxyapatite loaded with silver nitrate and lecithin were added, stirred at room temperature, filtered, and vacuum dried to obtain polycaprolactone-coated porous hydroxyapatite loaded with silver nitrate, which was recorded as AgNO3 / porous hydroxyapatite@PCL;

[0017] (3) adding zirconium oxychloride, polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and water into a reactor, stirring evenly and then performing a hydrothermal reaction. After the reaction is completed, filtering and freeze-drying are performed to obtain a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, recorded as AgNO3 / porous hydroxyapatite@PCL@ZrO2;

[0018] (4) mixing 100 parts by weight of a polycaprolactone-coated silver nitrate-supported porous hydroxyapatite / zirconia composite, 9 to 11 parts by weight of polypropylene, 18 to 22 parts by weight of polyethylene, 50 to 60 parts by weight of paraffin wax, 9 to 10 parts by weight of polyamide, 6 to 8 parts by weight of polyphenylene sulfide, and 5 to 7 parts by weight of polybutylene terephthalate, and homogenizing the mixture to obtain a uniform slurry, and injection-molding the slurry into a ceramic green body;

[0019] (5) The ceramic green body is placed in a sintering furnace, and the heating rate between room temperature and 200°C is 3°C / min, and the temperature is kept for 40 minutes; the heating rate between 200 and 350°C is 3.5°C / min, and the temperature is kept for 25 minutes to remove low-temperature decomposed organic matter in a staged manner and maintain the porous structure of hydroxyapatite; the heating rate between 350 and 400°C is 2°C / min, and the temperature is kept for 2 to 4 hours to remove polycaprolactone and degrease; the heating rate between 400 and 950°C is 3.5°C / min, and the temperature is kept for 2 to 3 hours; finally, it is naturally cooled to room temperature to obtain zirconia bioceramics.

[0020] Furthermore, in step (1), the mass ratio of the porous hydroxyapatite to the sodium carboxymethyl cellulose is (1.5-2): (0.3-0.5); the mass volume ratio of the porous hydroxyapatite to the silver nitrate solution is (1.5-2) g: 100 mL; the concentration of the silver nitrate solution is 0.5-1 mol·L -1 ;

[0021] Furthermore, in step (1), the stirring adsorption reaction time is 5 to 6 hours; and the vacuum drying temperature is 50 to 60°C.

[0022] Furthermore, in step (2), the molecular weight of polycaprolactone is 2000-4000, the mass volume ratio of polycaprolactone to ethyl acetate is (1-1.5) g:20 mL; the mass ratio of polycaprolactone to porous hydroxyapatite loaded with silver nitrate and lecithin is (1-1.5):(1.5-2):(0.1-0.2).

[0023] Furthermore, in step (2), the stirring time is 7 to 8 hours; and the vacuum drying temperature is 50 to 60°C.

[0024] Furthermore, in step (3), the mass ratio of the zirconium oxychloride to the polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite is 10:(1.5-2); and the mass volume ratio of the zirconium oxychloride to water is 10:(90-100) mL.

[0025] Furthermore, in step (3), the temperature of the hydrothermal reaction is 200-210° C., and the time of the hydrothermal reaction is 5-6 hours.

[0026] Furthermore, in step (4), the weight ratio of the polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, polypropylene, polyethylene, paraffin, polyamide, polyphenylene sulfide and polybutylene terephthalate is 100:(9-11):(18-22):(50-60):(9-10):(6-8):(5-7).

[0027] Furthermore, in step (4), the injection molding temperature is 200-260° C., the injection pressure is 50-70 MPa, and the molding time is 40-55 s;

[0028] Application of the zirconium oxide bioceramic obtained by the above method in ceramic ferrules.

[0029] Positive effects of the present invention:

[0030] (1) The zirconia bioceramic obtained by the present invention combines the good biological activity of hydroxyapatite with the excellent mechanical properties of zirconia. Zirconia itself has a high hardness. After adding hydroxyapatite, it can still maintain a high hardness and is not prone to wear and scratches. The shape and function of the ceramic ferrule can be maintained for a long time.

[0031] (2) The present invention loads silver nitrate onto the pore surface of hydroxyapatite, and then uses polycaprolactone to coat the porous hydroxyapatite loaded with silver nitrate to prevent the dissolution of silver nitrate during the subsequent preparation process. Then, the composite is mixed with zirconium oxychloride to prepare a porous hydroxyapatite / zirconium oxide composite loaded with polycaprolactone-coated silver nitrate. The composite is mixed with polypropylene, polyethylene, paraffin, polyamide, polyphenylene sulfide and polybutylene terephthalate and homogenized to obtain a slurry. The desired ceramic green body is injection molded and maintained by gradient heating to remove low-temperature decomposable organic matter and maintain the porous structure of hydroxyapatite to form a core-shell structure of AgNO3 / porous hydroxyapatite@ZrO2. When it is used as a ceramic ferrule, the silver nitrate loaded on the pore surface of the porous hydroxyapatite dissolves slowly due to the limitation of the pore structure, thereby achieving a long-lasting antibacterial effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a diagram of the preparation process of the zirconium oxide bioceramic described in the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the embodiments.

[0034] In the first aspect, a method for preparing zirconium oxide bioceramics is provided. Figure 1 , including the following steps:

[0035] (1) Add 1.5-2 g of porous hydroxyapatite and 0.3-0.5 g of sodium carboxymethyl cellulose to 100 mL of 0.5-1 mol·L -1 The adsorption reaction was stirred in a silver nitrate solution for 5 to 6 hours, and then filtered and dried in vacuum at 50 to 60°C to obtain porous hydroxyapatite with silver nitrate loaded on the pore surface, which was recorded as AgNO3 / porous hydroxyapatite;

[0036] (2) 1-1.5 g of polycaprolactone (molecular weight 2000-4000) was dissolved in 20 mL of ethyl acetate, and then 1-1.5 g of porous hydroxyapatite loaded with silver nitrate and 0.1-0.2 g of lecithin were added. The mixture was stirred at room temperature for 7-8 hours, filtered, and vacuum-dried at 50-60 °C to obtain polycaprolactone-coated porous hydroxyapatite loaded with silver nitrate, which was recorded as AgNO3 / porous hydroxyapatite@PCL.

[0037] (3) 10 g of zirconium oxychloride, 1.5-2 g of polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and 90-100 mL of water were added to a reactor, stirred evenly, and then hydrothermally reacted at 200-210° C. for 5-6 hours. After the reaction was completed, the mixture was filtered and freeze-dried to obtain a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, which was recorded as AgNO3 / porous hydroxyapatite@PCL@ZrO2;

[0038] (4) mixing 100 parts by weight of a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconia composite, 9 to 11 parts by weight of polypropylene, 18 to 22 parts by weight of polyethylene, 50 to 60 parts by weight of paraffin wax, 9 to 10 parts by weight of polyamide, 6 to 8 parts by weight of polyphenylene sulfide, and 5 to 7 parts by weight of polybutylene terephthalate, and homogenizing the mixture to obtain a uniform slurry, and injection molding the slurry into a ceramic green body, wherein the injection molding temperature is 200 to 260° C., the injection pressure is 50 to 70 MPa, and the molding time is 40 to 55 s;

[0039] (5) The ceramic green body is placed in a sintering furnace, and the heating rate between room temperature and 200°C is 3°C / min, and the temperature is kept for 40 minutes; the heating rate between 200 and 350°C is 3.5°C / min, and the temperature is kept for 25 minutes to remove low-temperature decomposed organic matter in a staged manner and maintain the porous structure of hydroxyapatite; the heating rate between 350 and 400°C is 2°C / min, and the temperature is kept for 2 to 4 hours to remove polycaprolactone and degrease; the heating rate between 400 and 950°C is 3.5°C / min, and the temperature is kept for 2 to 3 hours; finally, it is naturally cooled to room temperature to obtain zirconia bioceramics.

[0040] In a second aspect, the invention provides the application of the zirconium oxide bioceramic obtained by the above method in a ceramic ferrule.

[0041] Example 1

[0042] A method for preparing a zirconium oxide bioceramic comprises the following steps:

[0043] (1) Add 1.7 g of porous hydroxyapatite and 0.4 g of sodium carboxymethyl cellulose to 100 mL of 0.8 mol·L -1 The adsorption reaction was stirred in a silver nitrate solution for 5.5 hours, and after filtration and vacuum drying at 55°C, porous hydroxyapatite with silver nitrate loaded on the pore surface was obtained, which was recorded as AgNO3 / porous hydroxyapatite;

[0044] (2) 1.3 g of polycaprolactone (molecular weight 2000-4000) was dissolved in 20 mL of ethyl acetate, and then 1.3 g of porous hydroxyapatite loaded with silver nitrate and 0.15 g of lecithin were added. The mixture was stirred at room temperature for 7.5 hours, filtered, and vacuum-dried at 55 °C to obtain polycaprolactone-coated porous hydroxyapatite loaded with silver nitrate, which was recorded as AgNO3 / porous hydroxyapatite@PCL.

[0045] (3) 10 g zirconium oxychloride, 1.7 g polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and 95 mL water were added to a reactor, stirred evenly, and then hydrothermally reacted at 205 ° C for 5.5 hours. After the reaction, the mixture was filtered and freeze-dried to obtain a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, which was recorded as AgNO3 / porous hydroxyapatite@PCL@ZrO2;

[0046] (4) 100 parts by weight of a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconia composite, 10 parts by weight of polypropylene, 20 parts by weight of polyethylene, 55 parts by weight of paraffin wax, 9.5 parts by weight of polyamide, 7 parts by weight of polyphenylene sulfide, and 6 parts by weight of polybutylene terephthalate were mixed and homogenized to obtain a uniform slurry, and the slurry was injection molded into a ceramic ferrule green body at a temperature of 235° C., an injection pressure of 60 MPa, and a molding time of 50 s.

[0047] (5) The ceramic core green body is placed in a sintering furnace, and the heating rate between room temperature and 200°C is 3°C / min, and the temperature is kept for 40 minutes; the heating rate between 200 and 350°C is 3.5°C / min, and the temperature is kept for 25 minutes to remove low-temperature decomposed organic matter in a segmented manner and maintain the porous structure of hydroxyapatite; the heating rate between 350 and 400°C is 2°C / min, and the temperature is kept for 3 hours to remove polycaprolactone and degrease; the heating rate between 400 and 950°C is 3.5°C / min, and the temperature is kept for 2.5 hours; finally, it is naturally cooled to room temperature to obtain a zirconia bioceramic core.

[0048] Example 2

[0049] A method for preparing a zirconium oxide bioceramic comprises the following steps:

[0050] (1) Add 1.5 g of porous hydroxyapatite and 0.3 g of sodium carboxymethyl cellulose to 100 mL of 1 mol·L -1 The adsorption reaction was stirred in a silver nitrate solution for 5 hours, and then filtered and dried in vacuum at 50°C to obtain porous hydroxyapatite with silver nitrate loaded on the pore surface, which was recorded as AgNO3 / porous hydroxyapatite;

[0051] (2) 1 g of polycaprolactone (molecular weight 2000-4000) was dissolved in 20 mL of ethyl acetate, and then 1 g of porous hydroxyapatite loaded with silver nitrate and 0.1 g of lecithin were added. The mixture was stirred at room temperature for 7 h, filtered, and vacuum-dried at 50 °C to obtain polycaprolactone-coated porous hydroxyapatite loaded with silver nitrate, which was recorded as AgNO3 / porous hydroxyapatite@PCL.

[0052] (3) 10 g zirconium oxychloride, 1.5 g polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and 90 mL water were added to a reactor, stirred evenly, and then subjected to a hydrothermal reaction at 200 °C for 6 h. After the reaction was completed, the mixture was filtered and freeze-dried to obtain a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, which was recorded as AgNO3 / porous hydroxyapatite@PCL@ZrO2;

[0053] (4) 100 parts by weight of a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconia composite, 9 parts by weight of polypropylene, 22 parts by weight of polyethylene, 50 parts by weight of paraffin wax, 10 parts by weight of polyamide, 8 parts by weight of polyphenylene sulfide, and 7 parts by weight of polybutylene terephthalate were mixed and homogenized to obtain a uniform slurry, and the slurry was injection molded into a ceramic ferrule green body at a temperature of 260° C., an injection pressure of 50 MPa, and a molding time of 55 s.

[0054] (5) The ceramic core green body is placed in a sintering furnace, and the heating rate between room temperature and 200°C is 3°C / min, and the temperature is kept for 40 minutes; the heating rate between 200 and 350°C is 3.5°C / min, and the temperature is kept for 25 minutes to remove low-temperature decomposed organic matter in a segmented manner and maintain the porous structure of hydroxyapatite; the heating rate between 350 and 400°C is 2°C / min, and the temperature is kept for 4 hours to remove polycaprolactone and degrease; the heating rate between 400 and 950°C is 3.5°C / min, and the temperature is kept for 2 hours; finally, it is naturally cooled to room temperature to obtain a zirconia bioceramic core.

[0055] Example 3

[0056] A method for preparing a zirconium oxide bioceramic comprises the following steps:

[0057] (1) Add 2 g of porous hydroxyapatite and 0.5 g of sodium carboxymethyl cellulose to 100 mL of 0.5 mol·L -1 The adsorption reaction was stirred in a silver nitrate solution for 6 hours, and after filtration and vacuum drying at 60°C, porous hydroxyapatite with silver nitrate loaded on the pore surface was obtained, which was recorded as AgNO3 / porous hydroxyapatite;

[0058] (2) 1.5 g of polycaprolactone (molecular weight 2000-4000) was dissolved in 20 mL of ethyl acetate, and then 1.5 g of porous hydroxyapatite loaded with silver nitrate and 0.2 g of lecithin were added. The mixture was stirred at room temperature for 8 h, filtered, and vacuum-dried at 60 °C to obtain polycaprolactone-coated porous hydroxyapatite loaded with silver nitrate, which was recorded as AgNO3 / porous hydroxyapatite@PCL.

[0059] (3) 10 g of zirconium oxychloride, 2 g of polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and 100 mL of water were added to a reactor, stirred evenly, and then hydrothermally reacted at 210 °C for 5 hours. After the reaction was completed, the mixture was filtered and freeze-dried to obtain a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, which was recorded as AgNO3 / porous hydroxyapatite@PCL@ZrO2;

[0060] (4) 100 parts by weight of a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconia composite, 11 parts by weight of polypropylene, 18 parts by weight of polyethylene, 60 parts by weight of paraffin wax, 9 parts by weight of polyamide, 6 parts by weight of polyphenylene sulfide, and 5 parts by weight of polybutylene terephthalate were mixed and homogenized to obtain a uniform slurry, and the slurry was injection molded into a ceramic ferrule green body at a temperature of 200° C., an injection pressure of 70 MPa, and a molding time of 40 s.

[0061] (5) The ceramic core green body is placed in a sintering furnace, and the heating rate between room temperature and 200°C is 3°C / min, and the temperature is kept for 40 minutes; the heating rate between 200 and 350°C is 3.5°C / min, and the temperature is kept for 25 minutes to remove low-temperature decomposed organic matter in a segmented manner and maintain the porous structure of hydroxyapatite; the heating rate between 350 and 400°C is 2°C / min, and the temperature is kept for 2 hours to remove polycaprolactone and degrease; the heating rate between 400 and 950°C is 3.5°C / min, and the temperature is kept for 3 hours; finally, it is naturally cooled to room temperature to obtain a zirconia bioceramic core.

[0062] Example 4

[0063] A method for preparing a zirconium oxide bioceramic comprises the following steps:

[0064] (1) Add 2 g of porous hydroxyapatite and 0.3 g of sodium carboxymethyl cellulose to 100 mL of 1 mol·L -1 The adsorption reaction was stirred in a silver nitrate solution for 6 hours, and after filtration and vacuum drying at 60°C, porous hydroxyapatite with silver nitrate loaded on the pore surface was obtained, which was recorded as AgNO3 / porous hydroxyapatite;

[0065] (2) 1 g of polycaprolactone (molecular weight 2000-4000) was dissolved in 20 mL of ethyl acetate, and then 1.5 g of porous hydroxyapatite loaded with silver nitrate and 0.2 g of lecithin were added. The mixture was stirred at room temperature for 7 h, filtered, and vacuum-dried at 60 °C to obtain polycaprolactone-coated porous hydroxyapatite loaded with silver nitrate, which was recorded as AgNO3 / porous hydroxyapatite@PCL.

[0066] (3) 10 g zirconium oxychloride, 2 g polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and 100 mL water were added to a reactor, stirred evenly, and then subjected to a hydrothermal reaction at 210 °C for 6 h. After the reaction was completed, the mixture was filtered and freeze-dried to obtain a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, which was recorded as AgNO3 / porous hydroxyapatite@PCL@ZrO2;

[0067] (4) 100 parts by weight of a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconia composite, 11 parts by weight of polypropylene, 20 parts by weight of polyethylene, 55 parts by weight of paraffin wax, 10 parts by weight of polyamide, 8 parts by weight of polyphenylene sulfide, and 5 parts by weight of polybutylene terephthalate were mixed and homogenized to obtain a uniform slurry, and the slurry was injection molded into a ceramic ferrule green body at a temperature of 240° C., an injection pressure of 60 MPa, and a molding time of 45 s.

[0068] (5) The ceramic core green body is placed in a sintering furnace, and the heating rate between room temperature and 200°C is 3°C / min, and the temperature is kept for 40 minutes; the heating rate between 200 and 350°C is 3.5°C / min, and the temperature is kept for 25 minutes to remove low-temperature decomposed organic matter in a segmented manner and maintain the porous structure of hydroxyapatite; the heating rate between 350 and 400°C is 2°C / min, and the temperature is kept for 4 hours to remove polycaprolactone and degrease; the heating rate between 400 and 950°C is 3.5°C / min, and the temperature is kept for 2 hours; finally, it is naturally cooled to room temperature to obtain a zirconia bioceramic core.

[0069] Comparative Example 1

[0070] The method and parameters of this comparative example are the same as those of Example 1, except that steps (1) and (2) are omitted, and step (3) is modified to: 10 g zirconium oxychloride, 1.7 g porous hydroxyapatite, 100 mL 0.8 mol·L -1 The silver nitrate solution was added to the reaction kettle, stirred evenly, and then subjected to a hydrothermal reaction at 205° C. for 5.5 hours. After the reaction, the solution was filtered and freeze-dried to obtain a silver nitrate / porous hydroxyapatite / zirconium oxide composite.

[0071] Comparative Example 2

[0072] The method and parameters of this comparative example are the same as those of Example 1, except that the auxiliary agents in step (4) are 10 parts by weight of polypropylene, 20 parts by weight of polyethylene, and 55 parts by weight of paraffin.

[0073] The specific process of step (4) is to mix 100 parts by weight of a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, 15 parts by weight of polypropylene, 25 parts by weight of polyethylene, and 60 parts by weight of paraffin wax, and then homogenize to obtain a uniform slurry, and then injection mold the slurry into a ceramic green body at a temperature of 235° C., an injection pressure of 60 MPa, and a molding time of 50 s.

[0074] Comparative Example 3

[0075] The method and parameters of this comparative example are the same as those of Example 1, except that: in step (5), no staged heating and heating rate control are performed, the sintering furnace is directly heated to 950°C, and then the ceramic green body is placed in the sintering furnace and kept warm for 5.5 hours to obtain zirconia ceramics.

[0076] Performance testing:

[0077] (1) The density, hardness and inner diameter tolerance of the zirconia bioceramics prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were tested.

[0078] Table 1 Density, hardness and tolerance data of zirconia bioceramics

[0079] sample <![CDATA[Density (g / cm 3 )]]> Hardness (HRA) Inner diameter tolerance (μm) Example 1 3.86 82 ±0.5 Example 2 3.95 83 ±0.4 Example 3 3.82 80 ±0.7 Example 4 3.93 81 ±0.6 Comparative Example 1 4.01 81 ±0.6 Comparative Example 2 4.97 83 ±1.3 Comparative Example 3 5.99 89 ±1.7

[0080] As can be seen from Table 1, the preparation methods of Examples 1-4 yielded low-density, porous, dimensionally stable zirconia bioceramics with tight tolerances after sintering. However, after modifying the additives in Comparative Example 2, the density of the zirconia bioceramic produced increased significantly, resulting in significant dimensional variation and tolerance after sintering, which affected the precision of the ceramic structure. In Comparative Example 3, altering the sintering temperature setting resulted in a collapse of the porous hydroxyapatite pore structure, a significant increase in tolerance, and dimensional instability of the zirconia ceramic after sintering, affecting the precision of the ceramic structure.

[0081] (2) Antibacterial performance test of the zirconia bioceramics prepared in Example 1 and Comparative Examples 1 to 3.

[0082] Selection of strains: Standard strains of Escherichia coli and Staphylococcus aureus were inoculated into LB liquid medium and cultured in a constant temperature incubator at 37°C for 1 day. A piece of zirconia bioceramics prepared in Example 1 and Comparative Examples 1 to 3 of the same size was placed on a plate inoculated with Escherichia coli (inoculation size 1.2×10 7 CFU) and Staphylococcus aureus (inoculation size 1.2×10 7 The cells were cultured in 90 mm LB agar medium containing 500 CFU (100 μg / mL) and incubated in a 37°C constant temperature incubator for 18 h, and the size of the inhibition zone was recorded.

[0083] Table 2 Inhibition zone data of zirconia bioceramics prepared in Example 1 and Comparative Examples 1 to 3

[0084]

[0085] As can be seen from Table 2, in Example 1, because silver nitrate is loaded into the pores of porous hydroxyapatite, silver nitrate is more easily dissolved through the pores during the experiment, resulting in a larger inhibition zone. Since Comparative Example 1 does not load silver nitrate into the pores of porous hydroxyapatite, it is a zirconia bioceramic prepared by direct mixing, so that silver nitrate cannot be dissolved well and have an antibacterial effect. Although Comparative Example 2 uses porous hydroxyapatite loaded with silver nitrate, the tolerance is large and part of the pore structure collapses during the sintering process due to the problem of auxiliary agent selection, which hinders the dissolution of silver nitrate and weakens the antibacterial effect. Due to the sintering process, a large number of pore structures collapse in Comparative Example 3, forming a high-density zirconia ceramic, which makes it more difficult for silver nitrate to dissolve, so the antibacterial effect is the worst.

[0086] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in this application. The description and examples are to be considered merely as exemplary, and the present application is not limited to the precise structures described above and shown in the drawings, and various modifications and variations may be made without departing from the scope thereof.

Claims

1. A method for preparing zirconium oxide bioceramics, characterized in that: The steps include: (1) Porous hydroxyapatite and sodium carboxymethyl cellulose are added to a silver nitrate solution, stirred for adsorption reaction, filtered, and vacuum-dried to obtain porous hydroxyapatite with silver nitrate loaded on the pore surface, which is recorded as AgNO3 / porous hydroxyapatite; (2) Polycaprolactone was dissolved in ethyl acetate, and then porous hydroxyapatite loaded with silver nitrate and lecithin were added, stirred at room temperature, filtered, and vacuum dried to obtain polycaprolactone-coated porous hydroxyapatite loaded with silver nitrate, which was recorded as AgNO3 / porous hydroxyapatite@PCL; (3) adding zirconium oxychloride, polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite, and water into a reactor, stirring evenly and then performing a hydrothermal reaction. After the reaction is completed, filtering and freeze-drying are performed to obtain a polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, recorded as AgNO3 / porous hydroxyapatite@PCL@ZrO2; (4) mixing polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, polypropylene, polyethylene, paraffin wax, polyamide, polyphenylene sulfide, and polybutylene terephthalate, and homogenizing the mixture to obtain a uniform slurry, and injection-molding the slurry into a ceramic green body; (5) The ceramic green body is placed in a sintering furnace, and the heating rate between room temperature and 200°C is 3°C / min, and the temperature is kept for 40 minutes; the heating rate between 200 and 350°C is 3.5°C / min, and the temperature is kept for 25 minutes to remove low-temperature decomposed organic matter in a staged manner and maintain the porous structure of hydroxyapatite; the heating rate between 350 and 400°C is 2°C / min, and the temperature is kept for 2 to 4 hours to remove polycaprolactone and degrease; the heating rate between 400 and 950°C is 3.5°C / min, and the temperature is kept for 2 to 3 hours; finally, it is naturally cooled to room temperature to obtain zirconia bioceramics.

2. The method for preparing the zirconium oxide bioceramic according to claim 1, wherein: In step (1), the mass ratio of the porous hydroxyapatite to the sodium carboxymethyl cellulose is (1.5-2): (0.3-0.5); the mass volume ratio of the porous hydroxyapatite to the silver nitrate solution is (1.5-2) g: 100 mL; the concentration of the silver nitrate solution is 0.5-1 mol·L -1 .

3. The method for preparing the zirconium oxide bioceramic according to claim 1, characterized in that: In step (1), the stirring adsorption reaction time is 5 to 6 hours; and the vacuum drying temperature is 50 to 60°C.

4. The method for preparing the zirconium oxide bioceramic according to claim 1, characterized in that: In step (2), the molecular weight of polycaprolactone is 2000-4000, the mass volume ratio of polycaprolactone to ethyl acetate is (1-1.5) g:20 mL; the mass ratio of polycaprolactone to the porous hydroxyapatite loaded with silver nitrate and lecithin is (1-1.5):(1.5-2):(0.1-0.2).

5. The method for preparing the zirconium oxide bioceramic according to claim 1, characterized in that: In step (2), the stirring time is 7 to 8 hours; and the vacuum drying temperature is 50 to 60°C.

6. The method for preparing the zirconium oxide bioceramic according to claim 1, characterized in that: In step (3), the mass ratio of the zirconium oxychloride to the polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite is 10:(1.5-2); the mass volume ratio of the zirconium oxychloride to water is 10:(90-100) mL.

7. The method for preparing the zirconium oxide bioceramic according to claim 1, characterized in that: In step (3), the temperature of the hydrothermal reaction is 200-210° C., and the time of the hydrothermal reaction is 5-6 hours.

8. The method for preparing the zirconium oxide bioceramic according to claim 1, characterized in that: In step (4), the weight ratio of the polycaprolactone-coated silver nitrate-loaded porous hydroxyapatite / zirconium oxide composite, polypropylene, polyethylene, paraffin, polyamide, polyphenylene sulfide and polybutylene terephthalate is 100:(9-11):(18-22):(50-60):(9-10):(6-8):(5-7).

9. The method for preparing the zirconium oxide bioceramic according to claim 1, characterized in that: In step (4), the injection molding temperature is 200-260° C., the injection pressure is 50-70 MPa, and the molding time is 40-55 s.

10. Use of the zirconium oxide bioceramic obtained by the method of claim 1 in a ceramic ferrule.

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