A graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility and a preparation method thereof

Abstract

The present invention discloses a graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility and a preparation method thereof. The barium calcium zirconate titanate-based ceramic (Ba<subgt;0.85< / subgt;Ca<subgt;0.15< / subgt>Zr<subgt;0.1< / subgt>Ti<subgt;0.9< / subgt;)O<subgt;3< / subgt> is prepared according to the following steps: 1) proportioning, 2) ball milling, 3) drying, 4) calcination, 5) secondary ball milling, 6) drying, 7) sintering, 8) grinding and sieving. The graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic is prepared according to the following steps: 1) proportioning, 2) ball milling, 3) drying, 4) sieving, 5) sintering. The present invention combines the solid-phase sintering method and the rapid hot-pressing sintering method to successfully prepare the graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic. Moreover, the grain distribution of the prepared composite ceramic sample is relatively uniform, and the grain size is smaller, with high density. At the same time, the wettability and biocompatibility of the GO / BCZT composite piezoelectric ceramic material are relatively good. It is expected to further apply it in the field of biological materials and bone defect repair.

Description

Technical Field

[0001] The present technology relates to the field of functional ceramics, and particularly relates to a graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility and a preparation method thereof. Background Art

[0002] Bone, as a nanocomposite composed of living cells and minerals, is an important part of the human skeleton. However, due to congenital factors (such as genetics, infection, insufficient prenatal nutrition, etc.) or acquired factors (such as trauma, bone diseases, inflammation, etc.), bone tissue loss may occur, resulting in bone defects. Currently, the commonly used treatment plan for bone defects is to produce synthetic bone substitute materials that induce osteoconduction and integration, provide mechanical stability, and integrate them into the bone structure. Commonly used bone substitute materials mainly include medical metal materials, polymer materials, bioceramic materials, and composite materials, etc.

[0003] Among them, BCZT-based ceramic materials have excellent piezoelectric properties, can generate a large amount of electric charge and higher sensitivity, which is beneficial to improving the performance and response speed of sensors. They also have better electrode adhesion properties. When manufacturing devices such as biosensors, the connection between the electrode and the ceramic is more stable, which helps to improve the reliability and durability of the device. In particular, BCZT ceramics usually have relatively good biocompatibility and are suitable for applications in contact with organisms, such as biosensors, biomedical devices, etc. They do not produce significant toxicity or allergic reactions, which helps to reduce the adverse effects on biological tissues. Therefore, due to their good mechanical properties, excellent piezoelectric effect that can stimulate bone formation, and low cytotoxicity to human osteoblasts, BCZT-based ceramic materials have great potential to become artificial bone substitute materials.

[0004] Graphene and its derivatives have good ability to induce osteogenic differentiation of cells, can stimulate cell responses (cell adhesion, proliferation, and differentiation), and are expected to improve the biocompatibility of composite bioceramic materials. Among them, graphene oxide has the advantages of low production cost, large-scale production, easy processing, etc. Therefore, graphene oxide (GO) has become a potential substitute for graphene due to its similar structure and availability. And due to the presence of its functional groups (mainly hydroxyl groups and epoxy resins), graphene oxide shows excellent hydrophilicity, stable dispersibility, and high protein adsorption, which can minimize cytotoxicity.

[0005] Currently, solid-phase sintering is mainly used to prepare BCZT-based ceramic materials by mixing raw materials with powders, shaping them, drying them, and then sintering. It has the advantages of simple process and easy operation, and has been widely used in industry. However, it also has some disadvantages, such as high sintering temperature, difficult control of grain growth, and easy formation of pores. As a new type of electric field-assisted sintering principle and technology, rapid hot pressing sintering can quickly achieve dense sintering and high-temperature synthesis through direct current heating and axial pressure. The fully automatic program-controlled current regulation can activate the sintering process in the shortest time. The time for the entire densification process can be reduced to dozens of seconds to a few minutes, significantly improving the microstructure of the sample and enhancing its performance. The sintering speed is fast, the equipment investment is small, the cost performance is high, and the sintering process is precisely controllable: all sintering parameters can be accurately controlled (sintering temperature, pressing pressure, and ambient atmosphere, etc.). It is reliable, durable, and easy to operate, with a low sintering temperature and a short holding time, so that the sample grains have no time to grow. Summary of the Invention

[0006] In order to solve the above technical problems, the purpose of the present invention is to provide a graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility and its preparation method, in which the grain distribution is relatively uniform, the grain size is smaller, and it has high density and good biocompatibility.

[0007] To achieve the above object, the present invention provides the following technical solution: A preparation method of a graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility, which is characterized in that it is prepared according to the following method:

[0008] A Preparation of Barium Calcium Zirconate Titanate-Based Ceramic (Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 )O3

[0009] 1) Ingredient preparation: The raw materials barium carbonate, calcium carbonate, titanium dioxide, and zirconium dioxide powders are proportioned according to the corresponding stoichiometric ratio;

[0010] 2) Ball milling: The prepared raw materials are put into a ball milling tank for ball milling to mix the powders evenly;

[0011] 3) Drying: The wet materials are put into an oven for sufficient drying;

[0012] 4) Calcination: The dried powder is placed in a muffle furnace for calcination;

[0013] 5) Secondary ball milling: The calcined powder is subjected to secondary ball milling;

[0014] 6) Drying: The raw materials after secondary ball milling are put into an oven for drying;

[0015] 7) Sintering: The dried powder is placed in a tube furnace for sintering;

[0016] 8) Grinding and sieving: Grinding and pressing the sintered powder, and sieving to obtain barium calcium zirconate titanate ceramic powder;

[0017] B. Preparation of graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramics

[0018] 1) Ingredients: Graphene oxide is mixed with barium calcium zirconate titanate-based ceramic powder, wherein the molar ratio of graphene oxide to barium calcium zirconate titanate-based ceramic powder is 0.2%-0.5%:1;

[0019] 2) Ball milling: The prepared mixed materials are placed in a ball milling tank and ball milled;

[0020] 3) Drying: Dry the mixed material after ball milling;

[0021] 4) Sieving: Sieving the dried powder to obtain graphene oxide / barium calcium zirconate titanate ceramic composite powder;

[0022] 5) Sintering: The composite powder was sintered by rapid hot pressing to prepare a ceramic disc with a diameter of 12 mm and a thickness of 1.5 mm.

[0023] In the above solution: the purity of the barium carbonate, calcium carbonate, titanium dioxide, zirconium dioxide powder and graphene oxide is ≥99.9%.

[0024] In the above scheme: in step A and step B, Zr balls are used as the ball milling medium during ball milling. The ball milling medium is a mixture of Zr balls with diameters of 3 mm, 5 mm and 10 mm. The ball milling liquid is anhydrous ethanol. The ratio of raw material to anhydrous ethanol is 1 g:1.5 ml. The rotation speed is 300-500 rpm / min, and the ball milling time is 6-12 h.

[0025] In the above scheme: in step A and step B, drying is carried out by oven drying, and the oven drying conditions are drying at 80-100° C. for 12-16 hours.

[0026] In the above scheme: the calcination temperature in step A is set to start from room temperature and rise to 1100-1200°C at a rate of 3-5°C / min, and the holding time is 2-4h.

[0027] In the above scheme: in step A, the sintering temperature is set to start from room temperature and rise to 1300-1450°C at a rate of 3-5°C / min, and the holding time is 2-4h.

[0028] In the above scheme: in step A and step B, the size of the sieve used during sieving is 80-200 mesh.

[0029] In the above solution: In step B, the temperature setting for rapid hot pressing sintering starts from room temperature, rises to 1300 - 1450 °C at a rate of 50 - 100 °C / min, the holding time is 30 - 50 min, and it is carried out in a vacuum atmosphere with a pressure of 20 - 50 Mpa.

[0030] A graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility prepared by the preparation method of the graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility described above.

[0031] Beneficial effects: The present invention combines the solid-phase sintering method and the rapid hot pressing sintering method to successfully prepare a graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic. Moreover, the grain distribution of the prepared composite ceramic sample is relatively uniform, and the grain size is smaller, with high density. At the same time, the wettability and biocompatibility of the GO / BCZT composite piezoelectric ceramic material are relatively good. It is expected to be further applied in the field of biological materials and bone defect repair. Description of the Drawings

[0032] Figure 1 Is the X-ray diffraction pattern of xGO / BCZT ceramics, (a) 2θ = 20 - 80°, (b) the enlarged XRD pattern in the range of 44.5 - 46.5°.

[0033] Figure 2 Is the Raman spectrum of the xGO / BCZT composite piezoelectric ceramic.

[0034] Figure 3 Is the scanning electron microscope image of the xGO / BCZT composite piezoelectric ceramic, upper left x = 0.2 mol%, upper right x = 0.3 mol%, lower left x = 0.4 mol%, lower right x = 0.5 mol%.

[0035] Figure 4 Is the piezoelectric constant (d 33 ) of the xGO / BCZT composite piezoelectric ceramic.

[0036] Figure 5 Is the Vickers hardness map of the xGO / BCZT composite piezoelectric ceramic.

[0037] Figure 6 Is the water contact angle map of the xGO / BCZT composite piezoelectric ceramic.

[0038] Figure 7 Is the cytotoxicity detection map of the xGO / BCZT composite piezoelectric ceramic. Detailed Embodiments

[0039] The following further describes the present invention in conjunction with the drawings and embodiments.

[0040] Example 1

[0041] A preparation method of graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramics with good biocompatibility is prepared according to the following method:

[0042] A Preparation of barium calcium zirconate titanate-based ceramics (Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 )O3

[0043] 1) Batching: The raw materials barium carbonate, calcium carbonate, titanium dioxide, and zirconium dioxide powders are batched according to the corresponding stoichiometric ratios. The purities of barium carbonate, calcium carbonate, titanium dioxide, and zirconium dioxide powders are all ≥99.9%.

[0044] 2) Ball milling: The prepared raw materials are put into a ball milling tank for ball milling to mix the powders evenly. When ball milling, Zr balls are used as the ball milling medium. The ball milling medium is a mixture of Zr balls with diameters of 3 mm, 5 mm, and 10 mm. The ball milling liquid is anhydrous ethanol. The ratio of raw materials to anhydrous ethanol is 1 g:1.5 ml, the rotation speed is 300 - 500 rpm / min, and the ball milling time is 12 h.

[0045] 3) Drying: The wet materials are put into an oven for sufficient drying; the drying conditions in the oven are drying at 80°C for 16 h.

[0046] 4) Calcination: The dried powder is placed in a muffle furnace for calcination. The calcination temperature is set to start from room temperature and rise to 1100 - 1200°C at a rate of 3 - 5°C / min, and the holding time is 4 h.

[0047] 5) Secondary ball milling: The calcined powder is subjected to secondary ball milling. When ball milling, Zr balls are used as the ball milling medium. The ball milling medium is a mixture of Zr balls with diameters of 3 mm, 5 mm, and 10 mm. The ball milling liquid is anhydrous ethanol. The ratio of raw materials to anhydrous ethanol is 1 g:1.5 ml, the rotation speed is 300 - 500 rpm / min, and the ball milling time is 6 h.

[0048] 6) Drying: The raw materials after secondary ball milling are put into an oven for drying. The drying conditions in the oven are drying at 100°C for 12 h.

[0049] 7) Sintering: The dried powder is placed in a tube furnace for sintering; the sintering temperature is set to start from room temperature and rise to 1300 - 1450°C at a rate of 3 - 5°C / min, and the holding time is 2 h.

[0050] 8) Grinding and sieving: The sintered powder is ground and rolled, and sieved through an 80 - 200 mesh sieve to obtain barium calcium zirconate titanate ceramic powder.

[0051] B. Preparation of graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramics

[0052] 1) Ingredients: Graphene oxide and calcium barium zirconate titanate-based ceramic powder are mixed in a molar ratio of 0.2%:1, 0.3%:1, 0.4%:1, and 0.5%:1, respectively; the purity of the graphene oxide is ≥99.9%.

[0053] 2) Ball milling: The prepared mixed materials are placed in a ball mill and ball milled; Zr balls are used as the ball milling medium during ball milling. The ball milling medium is a mixture of Zr balls with diameters of 3 mm, 5 mm, and 10 mm. The ball milling liquid is anhydrous ethanol. The ratio of raw materials to anhydrous ethanol is 1 g:1.5 ml. The rotation speed is 300-500 rpm / min and the ball milling time is 8 hours.

[0054] 3) Drying: The ball-milled mixed material was dried in an oven at 80° C. for 14 h.

[0055] 4) Sieving: The dried powder was sieved through an 80-200 mesh sieve to obtain graphene oxide / barium calcium zirconate titanate ceramic composite powder.

[0056] 5) Sintering: The composite powders were sintered by rapid hot pressing to form ceramic discs with a diameter of 12 mm and a thickness of 1.5 mm, yielding xGO / BCZT composite piezoelectric ceramic materials, where x was 0.2%, 0.3%, 0.4%, and 0.5%, respectively. The rapid hot pressing sintering temperature was set starting from room temperature and increasing at a rate of 50-100°C / min to 1300-1450°C, with a holding time of 30 minutes, under vacuum at a pressure of 20-50 MPa.

[0057] Figure 1 X-ray diffraction patterns of xGO / BCZT ceramics, (a) 2θ = 20-80°, (b) magnified XRD patterns in the range of 44.5-46.5°. The addition of graphene causes a phase transition in the composite ceramic, and the characteristic diffraction peak of graphene (002) can be seen in the figure.

[0058] Figure 2 The Raman spectra of xGO / BCZT composite ceramics with different graphene oxide contents are shown in Figure 2. As the graphene oxide content increases, the characteristic peaks of graphene in the composite ceramic become more pronounced, and the composite ceramic material exhibits a multilayer graphene structure.

[0059] Depend on Figure 3 It can be seen that with the increase of graphene oxide content, the grain size of the composite ceramics gradually decreases, resulting in an increase in the densification degree of the composite ceramics.

[0060] from Figure 4It can be seen that with the increase in the content of graphene oxide, the piezoelectric properties of the composite ceramics first increase and then decrease. When the content of graphene oxide is 0.4 mol%, the optimal piezoelectric properties can be achieved.

[0061] It can be Figure 5 seen that with the increase in the content of graphene oxide, the hardness of the composite ceramics first increases and then decreases. When the graphene content is 0.4%, the hardness is the largest.

[0062] It can be Figure 6 seen that the contact angles of all composite ceramic samples are less than 90°, showing good wettability. Figure 7 shows the OD values of the xGO / BCZT composite ceramics after 1, 4, and 7 days of cell culture. The xGO / BCZT composite ceramics have no obvious toxicity to cells, can promote cell proliferation, and have good biocompatibility.

[0063] Example 2

[0064] A preparation method of graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramics with good biocompatibility is prepared according to the following method:

[0065] A barium calcium zirconate titanate-based ceramic (Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 )O3 preparation

[0066] 1) Ingredient preparation: The raw materials barium carbonate, calcium carbonate, titanium dioxide, and zirconium dioxide powders are proportioned according to the corresponding stoichiometric ratios. The purities of barium carbonate, calcium carbonate, titanium dioxide, and zirconium dioxide powders are all ≥99.9%.

[0067] 2) Ball milling: The prepared raw materials are put into a ball milling tank for ball milling to mix the powders evenly. When ball milling, Zr balls are used as the ball milling medium. The ball milling medium is a mixture of Zr balls with diameters of 3 mm, 5 mm, and 10 mm. The ball milling liquid is anhydrous ethanol. The ratio of raw materials to anhydrous ethanol is 1 g:1.5 ml, the rotation speed is 300 - 500 rpm / min, and the ball milling time is 12 h.

[0068] 3) Drying: The wet materials are put into an oven for sufficient drying; the drying conditions in the oven are drying at 80 °C for 16 h.

[0069] 4) Calcination: The dried powder is placed in a muffle furnace for calcination. The calcination temperature is set to start from room temperature and rise to 1100 - 1200 °C at a rate of 3 - 5 °C / min, and the holding time is 2 h.

[0070] 5) Secondary ball milling: The calcined powder was subjected to secondary ball milling. Zr balls were used as the milling medium. The milling medium was a mixture of Zr balls with diameters of 3 mm, 5 mm, and 10 mm. The milling liquid was anhydrous ethanol. The ratio of raw material to anhydrous ethanol was 1 g:1.5 ml. The milling speed was 300-500 rpm / min and the milling time was 6 hours.

[0071] 6) Drying: The secondary ball-milled raw material was placed in an oven for drying at 100°C for 12 hours.

[0072] 7) Sintering: The dried powder is placed in a tube furnace for sintering; the sintering temperature is set to start from room temperature and increase to 1300-1450°C at a rate of 3-5°C / min, and the holding time is 4 hours.

[0073] 8) Grinding and sieving: The sintered powder is ground and pressed, and passed through an 80-200 mesh sieve to obtain barium calcium zirconate titanate ceramic powder.

[0074] B. Preparation of graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramics

[0075] 1) Ingredients: Graphene oxide and calcium barium zirconate titanate-based ceramic powder are mixed in a molar ratio of 0.4%:1; the purity of the graphene oxide is ≥99.9%.

[0076] 2) Ball milling: The prepared mixed materials are placed in a ball mill and ball milled; Zr balls are used as the ball milling medium during ball milling. The ball milling medium is a mixture of Zr balls with diameters of 3 mm, 5 mm, and 10 mm. The ball milling liquid is anhydrous ethanol. The ratio of raw materials to anhydrous ethanol is 1 g:1.5 ml. The rotation speed is 300-500 rpm / min and the ball milling time is 8 hours.

[0077] 3) Drying: The ball-milled mixed material was dried in an oven at 80° C. for 14 h.

[0078] 4) Sieving: The dried powder was sieved through an 80-200 mesh sieve to obtain graphene oxide / barium calcium zirconate titanate ceramic composite powder.

[0079] 5) Sintering: The composite powder was sintered by rapid hot pressing to form ceramic discs with a diameter of 12 mm and a thickness of 1.5 mm. The sintering temperature was set from room temperature to 1300-1450°C at a rate of 50-100°C / min, with a holding time of 50 minutes, under a vacuum atmosphere at a pressure of 20-50 MPa. The resulting product had a piezoelectric constant of 19 pC / N, a hardness of 178 kg / mm², a water contact angle of 53°, and excellent wettability.

[0080] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramics with good biocompatibility, characterized in that, It is prepared according to the following method: Preparation of barium calcium zirconate titanate-based ceramic (Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 )O3 1) Ingredient preparation: The raw materials barium carbonate, calcium carbonate, titanium dioxide, and zirconium dioxide powders are proportioned according to the corresponding stoichiometric ratios; 2) Ball milling: The prepared raw materials are put into a ball milling tank for ball milling to mix the powders evenly; 3) Drying: The wet materials are put into an oven for thorough drying; 4) Calcination: The dried powder is placed in a muffle furnace for calcination; 5) Secondary ball milling: The calcined powder is subjected to secondary ball milling; 6) Drying: The raw materials after secondary ball milling are put into an oven for drying; 7) Sintering: The dried powder is placed in a tube furnace for sintering; 8) Grinding and sieving: The sintered powder is ground and rolled, and sieved to obtain barium calcium zirconate titanate ceramic powder; Preparation of B graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramics 1) Ingredient preparation: Graphene oxide is mixed with barium calcium zirconate titanate-based ceramic powder; the molar ratio of graphene oxide to barium calcium zirconate titanate-based ceramic powder is 0.2%-0.5%:1; 2) Ball milling: The prepared mixed materials are put into a ball milling tank for ball milling and mixing; 3) Drying: The ball-milled mixed materials are dried; 4) Sieving: The dried powder is sieved to obtain graphene oxide / barium calcium zirconate titanate ceramic composite powder; 5) Sintering: The composite powder is prepared into a ceramic wafer with a diameter of 12 mm and a thickness of 1.5 mm by rapid hot pressing sintering.

2. The preparation method of the graphene oxide / barium calcium titanate composite piezoelectric ceramic with good biocompatibility according to claim 1, characterized in that: The purities of the barium carbonate, calcium carbonate, titanium dioxide, zirconium dioxide powders, and graphene oxide are all ≥99.9%.

3. The preparation method of the graphene oxide / barium calcium titanate composite piezoelectric ceramic with good biocompatibility according to claim 2, wherein: In steps A and B, Zr balls are used as the ball milling medium during ball milling. The ball milling medium is a mixture of Zr balls with diameters of 3 mm, 5 mm, and 10 mm. The ball milling liquid is anhydrous ethanol. The ratio of raw materials to anhydrous ethanol is 1 g:1.5 ml, the rotation speed is 300-500 rpm / min, and the ball milling time is 6-12 h.

4. The preparation method of the graphene oxide / barium calcium titanate composite piezoelectric ceramic with good biocompatibility according to any one of claims 1-3, characterized in that: In steps A and B, drying is carried out using an oven. The conditions for oven drying are drying at 80-100°C for 12-16 h.

5. The preparation method of the graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility according to claim 4, characterized in that: In step A, the temperature of calcination is set to start from room temperature and rise to 1100-1200°C at a rate of 3-5°C / min, and the holding time is 2-4 h.

6. The preparation method of the graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility according to claim 5, characterized in that: In step A, the temperature of sintering is set to start from room temperature and rise to 1300-1450°C at a rate of 3-5°C / min, and the holding time is 2-4 h.

7. The preparation method of the graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility according to claim 6, wherein: In steps A and B, the mesh size of the sieve used during sieving is 80-200 mesh.

8. The preparation method of the graphene oxide / barium calcium titanate composite piezoelectric ceramic with good biocompatibility according to claim 7, characterized in that: In step B, the temperature of rapid hot pressing sintering is set to start from room temperature and rise to 1300-1450°C at a rate of 50-100°C / min, the holding time is 30-50 min, and it is carried out in a vacuum atmosphere with a pressure of 20-50 Mpa.

9. A graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility prepared by the preparation method of the graphene oxide / barium calcium zirconate titanate composite piezoelectric ceramic with good biocompatibility according to any one of claims 1-8.

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