Piezoelectric response enhanced toughened composite material, preparation method and application thereof

Abstract

The application discloses a piezoelectric response reinforced and toughened composite material and a preparation method and application thereof. The piezoelectric response reinforced and toughened composite material comprises organic polymer materials and inorganic piezoelectric materials, and the organic polymer materials and the piezoelectric materials are respectively connected to form a three-dimensional network structure. The piezoelectric response reinforced and toughened composite material considers the mechanical properties of the material as well as the electrical properties. Experimental results prove that the piezoelectric response reinforced and toughened composite material has excellent piezoelectric response and electrical stability, realizes the synergistic toughening and reinforcing of the material, has strong operability in clinical application, and can be used for development of biomedical materials.

Description

Technical Field

[0001] This invention relates to the field of tough materials, specifically to a piezoelectrically responsive reinforced and toughened composite material, its preparation method, and its application. Background Technology

[0002] Reinforced and toughened materials are a class of materials that significantly improve toughness and crack resistance while increasing hardness or strength. This property makes them widely used in numerous fields, such as construction, automotive, aerospace, electronics and communications, and medical devices. In these fields, materials not only need to withstand stress of a certain strength but also need sufficient toughness to resist deformation and fracture, thereby ensuring the safety and reliability of the products.

[0003] In clinical dentistry, implant abutments, inlays, crowns, and other restorations generally lack antibacterial properties, making them susceptible to bacterial invasion, leading to secondary caries or peri-implant disease and destruction of supporting bone tissue. Ultimately, the restorations may fall out or break due to insufficient supporting bone. Therefore, researchers hope to prevent secondary caries and peri-implant disease by developing restorations with self-antibacterial properties to prevent bacterial invasion. Current research mainly focuses on surface treatments of materials to exert antibacterial effects; however, surface treatments are easily affected by the oral environment and have poor long-term stability.

[0004] Research on reinforced and toughened materials has made some progress in the existing technology. For example, by adding diene or polyene crosslinking agents to the copolymerization of methyl methacrylate, the flexural strength of the material can be improved to some extent. However, this method often leads to increased brittleness and reduced impact resistance, meaning that a balance between strength and toughness is difficult to achieve. In addition, there are methods that utilize the interaction between polyol polymers and linking units to effectively improve the toughness and strength of materials by forming linking structures and closed-loop structures interwoven between polymer chains. While this method has achieved some success, certain challenges remain in terms of preparation processes and cost control.

[0005] In summary, reinforced and toughened materials, as novel materials possessing both high strength and high toughness, have broad application prospects in multiple fields. However, existing technologies still present some problems and challenges in the preparation and application of reinforced and toughened materials with both antibacterial and mechanical properties, requiring continuous exploration and innovation from researchers to promote the progress and development of materials science.

[0006] The information in the background section is merely intended to illustrate the general background of the invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] To address at least some of the technical problems in the prior art, this invention provides a piezoelectrically responsive reinforced and toughened composite material, its preparation method, and its applications. Specifically, this invention includes the following:

[0008] In a first aspect, the present invention provides a piezoelectric responsiveness-enhanced and toughened composite material, comprising an organic polymer material and an inorganic piezoelectric material, wherein the organic polymer material and the inorganic piezoelectric material are interconnected to form a three-dimensional network structure, wherein the mass ratio of the organic polymer material to the inorganic piezoelectric material ranges from 1:10 to 1:200.

[0009] In some embodiments, the piezoelectric responsiveness-enhanced and toughened composite material according to the present invention, wherein the inorganic piezoelectric material comprises barium titanate, strontium titanate, barium strontium titanate, lithium niobate, potassium niobate, sodium potassium niobate, bismuth ferrite, bismuth titanate, calcium bismuth niobate, bismuth iron titanate, sodium bismuth titanate, barium sodium bismuth titanate, zirconium oxide, lanthanum oxide, cerium oxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, calcium zirconate, barium calcium zirconate titanate, or at least one of the above-mentioned ternary or multi-component piezoelectric materials.

[0010] In some embodiments, the piezoelectrically responsive reinforced and toughened composite material according to the present invention includes an acrylate polymer.

[0011] In some embodiments, the piezoelectrically responsive reinforced and toughened composite material according to the present invention further includes a bonding-promoting unit coupled to the organic polymer material and the inorganic piezoelectric material, respectively.

[0012] In some embodiments, according to the piezoelectrically responsive reinforced and toughened composite material of the present invention, the promoting bonding unit is coupled to the organic polymer and the inorganic piezoelectric material via a compound reaction having the following structure:

[0013] X(CH2) n SiY3 formula I,

[0014] Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloyloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

[0015] In some embodiments, the piezoelectrically responsive reinforced and toughened composite material according to the present invention has a porosity of 0.1-50%.

[0016] A second aspect of the present invention provides a method for preparing the piezoelectrically responsive reinforced and toughened composite material as described above, comprising:

[0017] (1) The inorganic piezoelectric material is compacted and then sintered to obtain a porous green body. The compaction process includes dry pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa and holding it for 1-120 s to form a preliminary shape, and then compacting it with a pressure medium at 50-500 MPa and holding it for 1-120 s to obtain a dense green body.

[0018] (2) The sintered porous substrate is placed in a solution containing organic polymer materials and cured to obtain the reinforced and toughened composite material.

[0019] In some embodiments, according to the preparation method of the present invention, the sintering temperature is not lower than 1000°C.

[0020] In some embodiments, according to the preparation method of the present invention, the method further includes a step of polarizing the reinforced and toughened composite material, wherein the polarization field strength is 0.1-5 kV / mm, the polarization temperature is 10-40℃, and the treatment time is 1-120 min.

[0021] In some embodiments, according to the preparation method of the present invention, the step further includes treating the sintered porous substrate with a compound having the following structure:

[0022] X(CH2) n SiY3 formula I,

[0023] Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloyloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

[0024] A third aspect of the present invention provides the application of the piezoelectrically responsive reinforced and toughened composite material described herein in the preparation of biomedical materials (including but not limited to dental prostheses) that simultaneously possess antibacterial properties and mechanical service properties.

[0025] This invention achieves toughening and reinforcement of composite materials by controlling the sintering temperature of piezoelectric materials and the ratio of inorganic piezoelectric materials to organic polymer materials. Based on this, spatial electric field functionalization treatment of the reinforced and toughened composite materials can be applied to form reinforced and toughened composite materials with different electrical strengths, possessing excellent electrical and mechanical properties, and creating a long-term stable, self-antibacterial electrical microenvironment. The reinforced and toughened composite materials prepared by this invention are non-degradable, and the materials can maintain long-term stable electrical properties, avoiding potential health hazards such as ion release and absorption by the human body caused by material degradation.

[0026] Furthermore, due to its inherent ferroelectric properties, the reinforced and toughened composite material of the present invention can possess different piezoelectric responses after being functionalized by a spatial electric field. The predetermined spatial electrical microenvironment can achieve stable and controllable effects of promoting soft tissue cell adhesion and inhibiting bacteria. The antibacterial effect of the electrical microenvironment can enhance the sealing of surface soft tissue and inhibit the activity of surrounding bacteria, thereby preventing bacterial invasion. Attached Figure Description

[0027] Figure 1 Barium titanate reinforced and toughened composites with different sintering temperatures before and after toughening are shown.

[0028] Figure 2 The mass ratio of organic polymer materials to piezoelectric materials (barium titanate) within the material is shown.

[0029] Figure 3 The flexural strength of barium titanate matrices sintered at different temperatures before and after toughening with organic polymers is shown.

[0030] Figure 4 The elastic modulus of barium titanate matrices sintered at different temperatures before and after toughening with organic polymers is shown.

[0031] Figure 5 The fracture toughness of barium titanate matrices sintered at different temperatures before and after toughening with organic polymers is shown.

[0032] Figure 6 The XRD patterns of barium titanate matrix sintered at different temperatures are shown.

[0033] Figure 7 The comparison of flexural strength between barium titanate matrix sintered at 1200℃ and densely sintered barium titanate matrix before and after toughening with organic polymer materials is shown.

[0034] Figure 8 The elastic modulus of barium titanate matrix sintered at 1200℃ before and after toughening with organic polymer materials is shown to be compared with that of densely sintered barium titanate matrix.

[0035] Figure 9 The fracture toughness of barium titanate matrix sintered at 1200℃ before and after toughening is compared with that of densely sintered barium titanate matrix.

[0036] Figure 10 The image shows the observation of cracks in the reinforced and toughened composite material under nanoindentation.

[0037] Figure 11 This demonstrates that reinforced and toughened composite materials can effectively generate piezoelectric signals under pressure.

[0038] Figure 12A three-dimensional structural image of a porous barium titanate matrix sintered at 1200℃ is shown.

[0039] Figure 13 The results of electrical property measurements of reinforced and toughened composite materials after polarization treatment under different conditions are shown.

[0040] Figure 14 The results of electrical property measurements of reinforced and toughened composite materials sintered at different temperatures after polarization treatment are shown in (A) and (B) of electrical property measurements of reinforced and toughened composite materials sintered at different raw material ratios after polarization treatment.

[0041] Figure 15 The results of measuring the cell spread area and adhesion spot area on the surface of the reinforced and toughened composite material under pressure of different force values ​​are shown.

[0042] Figure 16 The results of cell proliferation and migration measurements on the surface of the reinforced and toughened composite material under pressure at different force values ​​are shown.

[0043] Figure 17 The experimental results of the antibacterial effect of the reinforced and toughened composite material are shown. Detailed Implementation

[0044] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0045] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0046] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0047] Reinforced and toughened composite materials

[0048] In one aspect, the present invention provides a piezoelectric responsiveness-enhanced and toughened composite material, the piezoelectric responsiveness-enhanced and toughened composite material comprising a piezoelectric material as a matrix and an organic polymer material filled in the matrix, wherein the organic polymer material and the piezoelectric material are interconnected to form a three-dimensional network (mesh) structure.

[0049] In this invention, examples of inorganic piezoelectric materials include, but are not limited to, barium titanate, strontium titanate, barium strontium titanate, lithium niobate, potassium niobate, sodium potassium niobate, bismuth ferrite, bismuth titanate, calcium bismuth niobate, ferric bismuth titanate, sodium bismuth titanate, barium sodium bismuth titanate, zirconium oxide, lanthanum oxide, cerium oxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, calcium zirconate, barium calcium zirconate titanate, or at least one of the above-mentioned ternary or multi-component piezoelectric materials. Those skilled in the art should understand that the above are only some examples of inorganic piezoelectric materials, and any inorganic piezoelectric material that can serve as a filling matrix for organic polymer materials can be used in this invention.

[0050] The morphology of the inorganic piezoelectric material of the present invention is not particularly limited, and it can be powder, granules, or fibers. In the case of granules, the particle size is not particularly limited, and can be 10 nm-200 μm, for example 100 nm-150 μm, 500 nm-150 μm, 1 μm-150 μm, or 50 μm-150 μm.

[0051] Unbound by any theoretical constraints, any organic polymer that can be cured in a porous inorganic piezoelectric matrix (e.g., but not limited to photocuring, thermocuring, etc.) can be used in the reinforcing and toughening composite material of this invention. Examples include, but are not limited to, acrylate polymers (copolymers), polyurethane polymers, organic polymers containing two or more epoxy groups, and phenolic polymers. In this invention, the organic polymer includes acrylate polymers, and examples of acrylate polymers include, but are not limited to, methyl methacrylate, ethyl acrylate, ethyl acrylate, and butyl acrylate. One acrylate polymer or a mixture of two or more acrylate polymers can be used. When using a mixture of two or more acrylate polymers, the ratio between the two or more acrylate polymers is not particularly limited and can be adjusted as needed. The molecular weight and viscosity of the acrylate polymer are not particularly limited, and those skilled in the art can select acrylate polymers with appropriate molecular weight and viscosity as needed.

[0052] In a preferred embodiment, the acrylate polymer used in this invention is a methacrylate polymer, including but not limited to methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, and benzyl methacrylate. In a specific embodiment, the acrylate polymer used in this invention is a mixture of bisphenol A glycerol dimethacrylate and triethylene glycol dimethacrylate.

[0053] In this invention, inorganic piezoelectric materials first form a porous matrix in the reinforced and toughened composite material, followed by the complete filling of the pores by organic polymer materials. Extensive research has revealed that in this three-dimensional network structure, the mass ratio of organic polymer materials to inorganic piezoelectric materials affects the mechanical properties of the reinforced and toughened composite material, and further influences its electrical properties. If the mass ratio of organic polymer materials to inorganic piezoelectric materials is too high, although the toughness requirement can be met, the elastic modulus and flexural strength are significantly reduced, and the electrical properties are also greatly diminished. On the other hand, if the mass ratio of organic polymer materials to inorganic piezoelectric materials is too low, although the elastic modulus of the composite material can be improved, it will lead to a decrease in the toughness and flexural strength of the composite material, thus making it unsuitable for use in biomedical materials (including but not limited to dental prostheses).

[0054] In this invention, the mass ratio of the organic polymer material to the inorganic piezoelectric material ranges from 1:10 to 1:200, preferably 1:10 to 1:150, even more preferably 1:10 to 1:145, even more preferably 1:10 to 1:100, and even more preferably 1:10 to 1:50, for example 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, and 1:50.

[0055] In the three-dimensional network structure of the piezoelectric responsive reinforced and toughened composite material of the present invention, a promoting bonding unit is further included to connect the organic polymer material and the piezoelectric material, and the promoting bonding unit is coupled to the organic polymer material and the inorganic piezoelectric material respectively. In a preferred embodiment, the promoting bonding unit is coupled to the organic polymer material and the inorganic piezoelectric material through a compound reaction having the following structure:

[0056] X(CH2) n SiY3 formula I,

[0057] Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloyloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

[0058] In one specific embodiment, the compound used in this invention is 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0059] Those skilled in the art will understand that the purpose of this invention can also be achieved without the use of compounds, i.e., without the presence of binding-promoting units in the three-dimensional structure.

[0060] In this invention, the reinforced and toughened composite material has a porosity of 0.1-50% before being filled with organic polymer material, preferably 1-50%, even more preferably 5-40%, further preferably 10-30%, and more preferably 10-20%.

[0061] Preparation method

[0062] One aspect of the present invention provides a method for preparing a piezoelectrically responsive reinforced and toughened composite material, comprising:

[0063] (1) The inorganic piezoelectric material is compacted and then sintered to obtain a porous green body. The compaction process includes dry pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa and holding it for 1-120 s to form a preliminary shape, and then dry pressing it at 50-500 MPa and holding it for 1-120 s to obtain a dense green body.

[0064] (2) The sintered porous substrate is placed in a solution containing organic polymer materials and cured to obtain the reinforced and toughened composite material.

[0065] In a preferred embodiment, the preparation method of the present invention includes:

[0066] (1') The inorganic piezoelectric material is compacted and then sintered to obtain a porous green body. The compaction process includes dry pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa and holding it for 1-120 s to form a preliminary shape, and then compacting it with a pressure medium at 50-500 MPa and holding it for 1-120 s to obtain a dense green body.

[0067] (2') The sintered porous green body (also referred to as porous piezoelectric material or porous substrate) is treated with a reagent, wherein the reagent is a compound having the following structure, and is coupled to the organic polymer material and the inorganic piezoelectric material through a reaction of the compound:

[0068] X(CH2) n SiY3 formula I,

[0069] Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

[0070] (3') The treated piezoelectric material is treated in a solution containing organic polymer materials to obtain the reinforced and toughened composite material.

[0071] Those skilled in the art should understand that the purpose of this invention can also be achieved without the use of reagents, i.e., without the absence of bonding-promoting units in the three-dimensional structure. This can be achieved by directly mixing the sintered material with a solution containing organic polymer materials, and then curing it to obtain an enhanced and toughened composite material.

[0072] Step (1') of the present invention is a compaction and sintering step. First, the piezoelectric material is compacted. Preferably, it includes a first compaction step and a second compaction step. The first compaction step includes dry pressing the powder or particles of the piezoelectric material through a pressure of 1-50 MPa, preferably 5-50 MPa, and even more preferably 10-50 MPa (e.g., 10, 20, 30, 40, 50 MPa) and holding it for 1-120 s, preferably 5-100 s, even more preferably 5-50 s, and even more preferably 10-50 s (e.g., 10, 15, 20, 25, 30, 35, 40, 45, 50 s) to initially form the blank. The second compaction involves compacting the green body after the first compaction using a pressure medium at 50-500 MPa, preferably 60-250 MPa, even more preferably 80-200 MPa, and further preferably 100-200 MPa (e.g., 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200 MPa) for 1-120 s, preferably 5-100 s, even more preferably 5-50 s, and further preferably 10-50 s (e.g., 10, 15, 20, 25, 30, 35, 40, 45, 50 s), to make the green body dense and uniform. The pressure medium is not particularly limited and can be a liquid medium such as water. The compaction temperature during the first and second compaction is not limited, but room temperature is preferred, and cold isostatic pressing is particularly preferred.

[0073] Following compaction and further sintering, the inventors discovered that sintering temperature affects the mechanical properties of the reinforced and toughened composite material, and further influences its electrical properties. If the sintering temperature is too low (e.g., not higher than 1000℃), although the toughness requirement can be met, the elastic modulus and flexural strength decrease significantly, and its electrical properties are also greatly reduced. These reduced mechanical and electrical properties prevent its application in biomedical materials (including but not limited to dental prostheses). On the other hand, if the sintering temperature is too high (e.g., not lower than 1300℃), although the elastic modulus of the composite material can be increased, it leads to a decrease in the toughness and flexural strength of the composite material, thus similarly preventing its application in biomedical materials (including but not limited to dental prostheses). In a preferred embodiment, the sintering temperature is in the range of 1000-1290°C, more preferably 1050-1290°C, even more preferably 1100-1280°C, and even more preferably 1150-1250°C, for example 1150, 1160, 1170, 1180, 1190, 1200, 1210, 1220, 1230, 1240, and 1250°C.

[0074] The heating method in step (1') is not specifically limited. Gradient heating can be used for sintering, for example, heating to a suitable temperature in the range of 50-200℃, 80-180℃, 80-150℃ or 80-120℃ and then sintering to obtain a porous matrix.

[0075] Step (2') of the present invention is a step of treating the sintered porous matrix with a reagent, which includes reacting a compound having formula (I), preferably a silane coupling agent, with water or a mixed solvent of water and alcohol under acidic conditions to obtain a coupling solution, and then keeping the matrix and the coupling solution under vacuum for a period of time, preferably 1-24 h, for example 1-12 h, 2-10 h, 2-8 h, 4-8 h, and then drying it under vacuum at 40-90°C (preferably 50-80°C, for example 50-70°C).

[0076] When using a mixed solvent of water and alcohol, the volume ratio of water, ethanol and the compound of formula (I) is 1-50:1-50:1, preferably 5-45:5-45:1, even more preferably 5-30:5-30:1, further preferably 10-25:10-25:1, and more preferably 10-20:10-20:1.

[0077] Step (3') of this invention is an organic polymer material filling and thermosetting step. To fully wet the matrix, the treated porous matrix and the organic polymer material are vacuum-assisted mixed and thermoset. The thermosetting temperature and time are not particularly limited and can be adjusted according to the adaptability of the selected organic polymer material. In a preferred embodiment, curing is performed at 80-200°C, preferably 80-180°C, even more preferably 80-160°C, further preferably 80-150°C for 0.1-24 h, preferably 1-12 h, and even more preferably 5-12 h.

[0078] The method of the present invention includes the step of optionally corona polarization treatment on the reinforced and toughened composite material, wherein the parameters of the corona polarization treatment include: a polarization field strength of 0.1-5 kV / mm, for example 0.1-4 kV / mm, 0.1-3 kV / mm, 0.1-2 kV / mm, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 2 kV / mm, etc.; and a polarization time of 1-120 min, preferably 15-90 min, such as 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90 min, etc.

[0079] application

[0080] One aspect of the present invention provides the application of piezoelectrically responsive reinforced and toughened composite materials in the preparation of biomedical materials (including but not limited to dental prostheses) that simultaneously possess antibacterial and mechanical service properties. Dental prostheses include, but are not limited to, implant abutments, inlays, crowns, artificial teeth, and denture bases.

[0081] The reinforced and toughened composite material of the present invention has broad-spectrum antibacterial properties, which can be used to inhibit or kill various bacteria, including Gram-positive bacteria represented by Streptococcus mutans or Gram-negative bacteria represented by Escherichia coli.

[0082] Example 1

[0083] I. Preparation Method

[0084] Barium titanate particles with a particle size of 30-100 μm are compacted and then sintered at 100°C intervals within a temperature range of 1000-1300°C to obtain a porous matrix. The compaction process includes a first compaction step and a second compaction step. The first compaction step involves subjecting barium titanate powder to dry pressing at 30 MPa for 25 seconds to initially form the green body. The second compaction step involves applying cold isostatic pressing at 180 MPa for 35 seconds after the first compaction to make the green body dense and uniform.

[0085] The substrate is subjected to coupling treatment, and the specific treatment steps include: mixing 45% volume water, 45% volume ethanol and 3% volume silane coupling agent KH570, and adding acetic acid to adjust the pH to 3-4 to prepare a silane coupling solution. Then, the barium titanate substrate is partially immersed in the solution, and the solution is fully wetted into the substrate under vacuum assistance. The substrate is then completely immersed in the solution for 6 hours, and then removed and vacuum dried at 60°C.

[0086] The coupled matrix is ​​filled with organic polymer material and thermosetting to enhance and toughen the piezoelectric material. The organic polymer material is a mixture of bisphenol A glycerol dimethacrylate and triethylene glycol dimethacrylate (Bis-GMA / TEGDMA), and the mass ratio of the organic polymer material to the piezoelectric material ranges from 1:10 to 1:200.

[0087] Control Group 1 (labeled as porous barium titanate in the figure): The material for Control Group 1 consisted of barium titanate particles with a particle size of 30-100 μm. After cold isostatic pressing, the material was sintered at 100°C intervals within a temperature range of 1000-1300°C to obtain a porous matrix. The cold isostatic pressing process included: after the barium titanate powder was initially formed by dry pressing at 30 MPa and holding for 25 seconds, it was then subjected to cold isostatic pressing at 180 MPa and held for 35 seconds to make the green body dense and uniform.

[0088] Control Group 2 (labeled as dense barium titanate in the figure): The material for Control Group 2 consisted of barium titanate particles with a particle size of 30-100 μm. After cold isostatic pressing, the particles were sintered at 1400℃ to obtain a dense barium titanate matrix. The cold isostatic pressing process included: after the barium titanate powder was initially formed by dry pressing at 30 MPa for 25 seconds, it was then subjected to cold isostatic pressing at 180 MPa for 35 seconds to make the green body dense and uniform.

[0089] For both the un-toughened and toughened materials, the flexural strength and elastic modulus were tested using a three-point bending test, and the fracture toughness was tested using a single-sided V-groove beam method. Furthermore, X-ray diffraction measurements were performed on barium titanate matrices sintered at different temperatures.

[0090] II. Results

[0091] Figure 1 Images of barium titanate reinforced and toughened composite materials with different sintering temperatures before and after toughening are shown. The top column shows the barium titanate reinforced and toughened material before toughening, and the bottom column shows the barium titanate reinforced and toughened composite material after toughening.

[0092] Figure 2The results show the mass ratio of polymer to barium titanate in the material, which can vary from 1:10 to 1:200. At a sintering temperature of 1200°C, the mass ratio of polymer to barium titanate is between 1:35 and 1:36.

[0093] Figure 3 The flexural strength of barium titanate matrices sintered at different temperatures before and after toughening with organic polymers is shown. The results indicate that the flexural strength of the barium titanate matrix is ​​significantly enhanced after toughening with organic polymers, with the barium titanate matrix sintered at 1200℃ exhibiting the highest flexural strength after being filled with organic polymers.

[0094] Figure 4 The elastic modulus of barium titanate matrices sintered at different temperatures before and after toughening with organic polymer materials is shown. The results show that the barium titanate matrix sintered at 1200℃ has the elastic modulus (16-20.3 GPa) closest to that of natural dentin after being filled with organic polymer materials, which is beneficial for the downward transmission of occlusal forces.

[0095] Figure 5 The fracture toughness data of barium titanate matrices sintered at different temperatures before and after toughening with organic polymers are shown. The results indicate that the barium titanate matrix sintered at 1200℃ exhibits higher fracture toughness after toughening. In summary, the barium titanate matrix sintered at 1200℃ possesses the best mechanical properties after toughening with organic polymers.

[0096] Figure 6 The XRD patterns of barium titanate matrix sintered at different temperatures are shown. It can be seen that the crystal phase of the barium titanate matrix did not change at the sintering temperature of the preparation method of the present invention, and both were tetragonal phases as before sintering.

[0097] Figure 7 The comparison of flexural strength between barium titanate matrix sintered at 1200℃ before and after toughening and barium titanate matrix sintered at density is shown. The flexural strength of barium titanate toughened with organic polymer is significantly higher than that of barium titanate matrix alone.

[0098] Figure 8 The comparison of the elastic modulus of barium titanate matrix sintered at 1200℃ before and after toughening with that of densely sintered barium titanate matrix is ​​shown. The elastic modulus of barium titanate toughened with organic polymer material is closer to that of natural dentin.

[0099] Figure 9 The fracture toughness of barium titanate matrix sintered at 1200℃ before and after toughening is compared with that of dense sintered barium titanate matrix. The fracture toughness of barium titanate toughened with organic polymer material is comparable to that of dense barium titanate matrix.

[0100] Figure 10The study shows the cracks in barium titanate toughened with organic polymers under nanoindentation. Crack bridging by organic polymers is observed at the cracks, thus clarifying the toughening mechanism by which organic polymers enhance the mechanical strength of barium titanate through crack bridging.

[0101] Figure 11 This invention demonstrates that even after toughening and reinforcement with organic polymers, the barium titanate matrix can still effectively generate piezoelectric signals under pressure. Furthermore, the invention utilizes high-precision CT scanning to construct a three-dimensional structural image of a porous barium titanate matrix sintered at 1200℃, as shown below. Figure 12 As shown, the pores are basically evenly distributed.

[0102] In summary, the mechanical strength of piezoelectric materials can be enhanced by adding organic polymer materials without significantly affecting the piezoelectric properties of the material itself.

[0103] Example 2

[0104] The reinforced and toughened composite material prepared in Example 1 was subjected to polarization treatment. The polarization conditions were: polarization time 15-90 minutes, polarization field strength 1 kV / mm, polarization medium air, and polarization temperature 25℃.

[0105] The results are as follows Figure 13 As shown in Figure A, the piezoelectric constant d of the reinforced and toughened composite material after polarization at different times is illustrated. 33 Figure B shows the surface potential data of the reinforced and toughened composite material after polarization for different times. These results indicate that the residual polarization properties of the material can be controlled by adjusting the polarization time. Figure C shows the piezoelectric signal images of the reinforced and toughened composite material after polarization for different times under a pressure of 200 N. Figure D shows the piezoelectric intensity data of the reinforced and toughened composite material after polarization for different times under a pressure of 200 N, indicating that the piezoelectric intensity is positively correlated with the polarization time. Figure E shows the piezoelectric signal diagrams of the reinforced and toughened composite material after 90 minutes of polarization under different pressures. Figure F shows the piezoelectric intensity data of the reinforced and toughened composite material after 90 minutes of polarization under different pressures, indicating that the piezoelectric intensity is positively correlated with the applied pressure. In summary, the required piezoelectric intensity of the reinforced and toughened composite material under different pressure conditions can be achieved by adjusting the polarization time. In this embodiment, the frequency of pressure applied to the composite material is 1.5 times / second, which is the normal physiological chewing frequency of a human.

[0106] This embodiment further demonstrates that barium titanate matrices sintered at different temperatures were polarized for 90 minutes after being filled with organic polymer materials, and the piezoelectric voltage strength data were tested under a pressure of 200 N. The results are as follows: Figure 14 As shown, barium titanate matrix sintered at 1200℃ exhibits significantly improved piezoelectric voltage strength after toughening compared to other temperatures (e.g., Figure 14 (As shown in Figure A).

[0107] This embodiment further subjected the reinforced and toughened composite materials with different raw material ratios to polarization for 90 minutes, and tested the piezoelectric voltage strength data under a pressure of 200 N. The results are as follows: Figure 14 As shown in Figure B, different raw material ratios affect the piezoelectric properties of the reinforced and toughened composite material. When the sintering temperature is 1200℃, the mass ratio of organic polymer material to piezoelectric material is 1:35 to 1:36, and the reinforced and toughened composite material has a significantly improved piezoelectric voltage strength.

[0108] Example 3

[0109] I. Effects of reinforced and toughened composite materials on gingival fibroblasts

[0110] Gingival fibroblasts were seeded onto the surface of a reinforced and toughened composite material after 90 minutes of polarization. Different pressure values ​​were applied to the reinforced and toughened composite material, with pressure applied 1200 times at a frequency of 1.5 times / second (half the number of chewing cycles per day). After 6 hours, immunofluorescence staining was performed on the cell adhesion plaques to measure the cell spreading area and adhesion plaque area under different pressure values. The control group was made of commercially available grade IV pure titanium, and its size was the same as the reinforced and toughened composite material.

[0111] The results are as follows Figure 15 As shown in Figures A and B, the cell spreading area and plaque area are maximized at approximately 100 N pressure (approximately 4.5 V). Figure C shows the ratio of plaque area to cell spreading area, which reaches its maximum at 100 N pressure. Figure D shows the quantitative distribution of gingival fibroblast cell spreading area, which is maximized at 100 N pressure.

[0112] II. CCK-8 assay of reinforced and toughened composite materials on cell proliferation

[0113] Gingival fibroblasts were seeded onto the surface of the reinforced and toughened composite material after 90 minutes of polarization. Pressure of varying forces was applied to the reinforced and toughened composite material at a frequency of 1.5 times / second for 2400 times daily. CCK-8 tests were performed at 1 and 3 days. The control group was made of commercially available grade IV pure titanium, and its size was identical to that of the reinforced and toughened composite material.

[0114] The results are as follows Figure 16 As shown in Figure A, after 3 days, cell proliferation was significantly enhanced under 100 N pressure (approximately 4.5 V).

[0115] III. Cell Scratch Test of Reinforced and Toughened Composite Materials

[0116] Using a cell-based scratch healing insert, gingival fibroblasts were seeded onto the surface of a reinforced and toughened composite material after 90 minutes of polarization. Pressure of varying forces was applied to the reinforced and toughened composite material at a frequency of 1.5 times / second for 2400 cycles. Cell nuclei were stained one day later to observe scratch healing. The control group was made of commercially available grade IV pure titanium, and its size was identical to that of the reinforced and toughened composite material.

[0117] The results are as follows Figure 16 As shown in Figure B, cell migration activity is significantly enhanced under 100 N pressure (approximately 4.5 V).

[0118] IV. Antibacterial Experiment of Reinforced and Toughened Composite Materials

[0119] Streptococcus mutans, a common oral pathogen, was inoculated onto the surface of the reinforced and toughened composite material after 90 minutes of polarization. Pressure of varying values ​​was applied to the reinforced and toughened composite material, with 1200 pressure cycles at a frequency of 1.5 cycles / second. For implant abutments, the sealing effect on marginal soft tissue is more important than the antibacterial effect; to avoid affecting the composite material's soft tissue integration promotion effect, the maximum force value was selected to be 100 N. The control group material was commercially available grade IV pure titanium, and the size of the control group was the same as that of the reinforced and toughened composite material.

[0120] The results of the antibacterial effect experiment are as follows: Figure 17 As shown in Figure A, the bacterial colony count decreased significantly under 50 N pressure. The quantitative statistical results of bacterial count are as follows: Figure 17 As shown in Figure B.

[0121] Streptococcus mutans was inoculated onto the surface of the reinforced and toughened composite material after 90 minutes of polarization. After 12 hours of incubation, pressure of varying values ​​was applied to the reinforced and toughened composite material at a frequency of 1.5 times / second, 1200 times in total. Incubation continued for another 12 hours, and crystal violet staining was used to quantify bacterial biofilm formation. The results were consistent with the antibacterial plate experiment; minimal bacterial biofilm formation was observed under 50 N pressure (e.g., ...). Figure 17 (As shown in Figure C).

[0122] After inoculating the surface of a reinforced and toughened composite material with Streptococcus mutans, a common oral pathogen, for 90 minutes after polarization, pressure of different values ​​was applied to the reinforced and toughened composite material. Pressure was applied 2400 times at a frequency of 1.5 times / second. After 24 hours, live and dead bacteria were stained and images were taken. The results matched those of previous antibacterial experiments (e.g., ...). Figure 17 (as shown in Figure D).

[0123] In summary, the piezoelectric signal of reinforced and toughened composite materials has a significant effect on promoting soft tissue adhesion, while also ensuring a certain antibacterial effect, which can prevent the occurrence of secondary oral caries, peri-implant disease, etc.

[0124] The reinforced and toughened composite material provided by this invention is highly operable in clinical applications. During the application of the reinforced and toughened composite material, it exhibits excellent piezoelectric response and electrical stability, while achieving synergistic reinforcement of mechanical and toughening properties. It considers both electrical characteristics and mechanical properties of the material, further realizing the synergistic effect of promoting cell adhesion, inhibiting bacteria and mechanical toughening, ensuring the feasibility of clinical use, and contributing to the development of biomedical materials, such as helping to prevent secondary caries, peri-implant disease and other diseases, and to ensure the long-term stability of implants.

[0125] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. Various adjustments or changes may be made to the exemplary embodiments described in this specification without departing from the scope or spirit of the invention. The scope of the claims should be interpreted in the broadest possible sense to cover all modifications and equivalent structures and functions.

Claims

1. A piezoelectrically responsive reinforced and toughened composite material, characterized in that, The material comprises organic polymer materials and inorganic piezoelectric materials, wherein the organic polymer materials and the inorganic piezoelectric materials are interconnected to form a three-dimensional network structure. The mass ratio of the organic polymer materials to the inorganic piezoelectric materials ranges from 1:10 to 1:

200. The inorganic piezoelectric materials include at least one of barium titanate, barium strontium titanate, lithium niobate, potassium niobate, sodium potassium niobate, calcium bismuth niobate, bismuth ferrite, bismuth titanate, bismuth iron titanate, sodium bismuth titanate, barium sodium bismuth titanate, and calcium barium zirconate titanate. The organic polymer materials are acrylate polymer organic polymer materials. The piezoelectrically responsive reinforced and toughened composite material is prepared by the following method: (1) The inorganic piezoelectric material is compacted and then sintered to obtain a porous green body with a porosity of 0.1-50% and a sintering temperature of 1000-1290℃. (2) The sintered porous substrate is placed in a solution containing organic polymer materials and cured to obtain the reinforced and toughened composite material; The method further includes a step of polarizing the reinforced and toughened composite material.

2. The piezoelectrically responsive reinforced and toughened composite material according to claim 1, characterized in that, The acrylate polymer organic polymer material includes at least one of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, and paraben methacrylate.

3. The piezoelectrically responsive reinforced and toughened composite material according to claim 1, characterized in that, The reinforced and toughened composite material further includes a bonding-promoting unit, which is coupled to the organic polymer material and the inorganic piezoelectric material, respectively.

4. The piezoelectrically responsive reinforced and toughened composite material according to claim 3, characterized in that, The promoting bonding unit is coupled to the organic polymer and the inorganic piezoelectric material through a compound reaction having the following structure: X(CH2) n SiY3 of formula I Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloyloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

5. The method for preparing the piezoelectrically responsive reinforced and toughened composite material according to any one of claims 1-4, characterized in that, include: (1) The inorganic piezoelectric material is compacted and then sintered to obtain a porous green body. The compaction process includes dry pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa and holding it for 1-120 s to form a preliminary shape, and then compacting it with a pressure medium at 50-500 MPa and holding it for 1-120 s to obtain a dense green body. (2) The sintered porous substrate is placed in a solution containing organic polymer materials and cured to obtain the reinforced and toughened composite material.

6. The method for preparing the piezoelectrically responsive reinforced and toughened composite material according to claim 5, characterized in that, The process further includes treating the sintered porous substrate with a compound having the structure of Formula I. X(CH2) n Formula I of SiY3 Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloyloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

7. The method for preparing the piezoelectrically responsive reinforced and toughened composite material according to claim 5, characterized in that, The polarization field strength is 0.1-5 kV / mm, the polarization temperature is 10-40℃, and the processing time is 1-120 min.

8. The application of the piezoelectrically responsive reinforced and toughened composite material according to any one of claims 1-4 in the preparation of biomedical materials that simultaneously possess antibacterial properties and mechanical service properties.

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