Piezoelectric / conductive difunctional composite nanoparticle with barium titanate (at) graphene-like carbon layer core-shell structure and preparation method and application thereof
By preparing a graphene-like carbon shell on the surface of barium titanate nanoparticles, the combination of piezoelectric and conductive properties is achieved, which solves the problem of insufficient combination of piezoelectric/conductive materials in the existing technology and improves the effect of biomedical applications.
Patent Information
- Application Number
- CN202510980834.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-16
- Publication Date
- 2025-10-21
AI Technical Summary
The existing technology lacks piezoelectric/conductive bifunctional composite materials that efficiently combine piezoelectric materials and conductive materials, which cannot fully utilize the synergistic advantages of the two and limits their application potential in the biomedical field.
By preparing a graphene-like carbon shell on the surface of barium titanate nanoparticles, combining piezoelectric materials and conductive materials, composite nanoparticles with a barium titanate@graphene-like carbon layer core-shell structure are formed, achieving a combination of piezoelectric and conductive properties.
This composite material can promote bone tissue growth and repair, enhance nerve regeneration, and provide a smart scaffold for simultaneous monitoring and treatment using multifunctional biomaterials in the biomedical field.
Smart Images
Figure CN120815218A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of biomedical materials, particularly multifunctional composite materials for tissue engineering and nerve repair. Specifically, the present invention relates to a piezoelectric / conductive bifunctional composite nanoparticle with a barium titanate and graphene-like carbon core-shell structure, as well as its preparation method and application. Background Art
[0002] Piezoelectric materials are a class of materials that can convert mechanical energy into electrical energy. They have characteristics such as fast response speed, high sensitivity, and corrosion resistance. In the biomedical field, piezoelectric materials are widely used in ultrasound imaging, biosensors, energy harvesting, and implantable medical devices (such as cochlear implants and pacemakers). For example, polyvinylidene fluoride (PVDF), as an organic piezoelectric material, is used to manufacture flexible biosensors and energy harvesters due to its excellent biocompatibility and piezoelectric properties. In addition, piezoelectric materials can also be used in bone tissue engineering, generating electric fields through mechanical stimulation to promote the growth and repair of bone tissue. Barium titanate, as a common piezoelectric material, has been widely studied for use in the biomedical field.
[0003] Conductive materials also have a wide range of applications in the biomedical field, including neural stimulation, tissue engineering, biosensors, and drug delivery. Conductive polymers and nanomaterials (such as graphene and carbon nanotubes) are used to manufacture neural electrodes, tissue engineering scaffolds, and wound dressings due to their excellent conductivity, biocompatibility, and mechanical properties. For example, conductive hydrogels and nanofibers have been used to promote nerve regeneration and bone tissue repair. In addition, conductive materials can also regulate cell behavior and accelerate tissue healing through electrical stimulation. Graphene-like structural materials are two-dimensional carbon materials with excellent conductivity, high specific surface area, good mechanical properties, and controllable surface properties.
[0004] However, the prior art in this field still lacks a piezoelectric / conductive bifunctional composite material that efficiently combines piezoelectric materials with conductive materials. Summary of the Invention
[0005] In response to the shortcomings of the existing technology, the present invention combines piezoelectric materials with conductive materials to develop a piezoelectric / conductive bifunctional composite nanoparticle with a barium titanate@graphene-like carbon layer core-shell structure, and utilizes its piezoelectric and conductive properties to provide an innovative solution for tissue repair and nerve regeneration. The composite nanoparticles of the present invention combine piezoelectric materials with conductive materials, which can give full play to the synergistic advantages of the two and bring new possibilities for biomedical applications. Piezoelectric materials can generate electric fields through mechanical stimulation, while conductive materials can conduct and regulate electric fields, thereby achieving more efficient electrical stimulation and signal conduction. This composite material can not only promote the growth and repair of bone tissue, but may also further enhance the tissue repair effect by regulating nerve regeneration. In addition, this combination also provides a basis for the development of multifunctional biomaterials, such as smart stents for simultaneous monitoring and treatment.
[0006] The present invention is achieved through the following technical solutions: A barium titanate and graphene-like carbon core-shell structured piezoelectric / conductive dual-functional composite nanoparticle characterized by a barium titanate core coated with a graphene-like carbon shell. Through an innovative surface modification and composite process, the graphene-like carbon shell is formed on the surface of the barium titanate nanoparticle, achieving both piezoelectric and conductive properties within the same material.
[0007] Alternatively, in the composite nanoparticles described above, the graphene-like carbon shell is prepared by polymerizing tannic acid on the surface of barium titanate nanoparticles in a neutral or alkaline environment to form an organic layer, followed by hydrothermal carbonization and atmospheric sintering. This method organically combines the piezoelectric material (barium titanate) with the conductive material (graphene-like carbon layer) by polymerizing tannic acid on the surface of barium titanate nanoparticles in a neutral environment to form an organic layer, followed by hydrothermal carbonization and atmospheric sintering. Ultimately, these composite nanoparticles not only retain the piezoelectric properties of barium titanate but also incorporate the high conductivity and biocompatibility of the graphene-like carbon layer, achieving a composite of conductive and piezoelectric materials.
[0008] As an option, in the above composite nanoparticles, the particle size of the barium titanate nanoparticles is in the range of 50-200 nm.
[0009] As an optional manner, in the above-mentioned composite nanoparticles, the thickness of the graphene-like carbon shell is 1-12 nm. This thickness range can enhance the piezoelectric properties of the barium titanate nanoparticles and increase the electrical conductivity.
[0010] The present invention also provides a method for preparing the composite nanoparticles, which is characterized by comprising the following steps: (1) Preparation of barium titanate nanoparticles with tannic acid shell; (2) Hydrothermal carbonization; (3) Atmosphere sintering.
[0011] As an optional manner, in the above preparation method, the step (1) is specifically as follows: In a neutral or alkaline environment, barium titanate nanoparticles are mixed with tannic acid to form a tannic acid coating layer on the surface of the barium titanate; Furthermore, the pH value of the neutral or alkaline environment is 6.8-8.5; the concentration of the tannic acid is 0.5-2.0 mg / mL, which can achieve good solubility while maintaining high efficiency.
[0012] As an optional manner, in the above preparation method, the step (2) is specifically as follows: The barium titanate nanoparticles coated with tannic acid are placed in a hydrothermal solution at 120-180° C. for hydrothermal carbonization, thereby forming a hydrothermal carbon layer on the surface of the barium titanate to obtain barium titanate nanoparticles with a hydrothermal carbon shell layer; Furthermore, the solution used in the hydrothermal carbonization is a neutral or alkaline solution of tannic acid, wherein the concentration of tannic acid is the same as that of tannic acid in step (1), and the hydrothermal carbonization reaction time is 12-24 hours.
[0013] As an optional manner, in the above preparation method, the step (3) is specifically as follows: The barium titanate nanoparticles with a hydrothermal carbon shell prepared in step (2) are sintered in a protective atmosphere or a vacuum environment to obtain piezoelectric / conductive bifunctional composite nanoparticles with a barium titanate@graphene-like carbon layer core-shell structure.
[0014] As an optional manner, in the above preparation method, the atmosphere sintering temperature is 400-800° C., the sintering atmosphere is nitrogen or argon, and the sintering time is 1-2 hours.
[0015] The present invention also provides an application of the composite nanoparticles, characterized in that the composite nanoparticles are used to prepare tissue regeneration and / or nerve repair materials.
[0016] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.
[0017] Beneficial effects of the present invention: (1) The present invention successfully integrates piezoelectric and conductive properties by coating the surface of barium titanate nanoparticles with a graphene-like carbon shell. This composite structure not only retains the piezoelectric properties of barium titanate, but also introduces the high conductivity and biocompatibility of the graphene-like carbon layer.
[0018] (2) The present invention significantly improves the biocompatibility and cell adhesion of barium titanate nanoparticles by forming a graphene-like carbon shell, making them more suitable for use in nerve repair and tissue engineering.
[0019] (3) The composite material of the present invention not only directly promotes cell growth and differentiation through its piezoelectric properties, but also regulates nerve regeneration through its conductive properties, further enhancing the tissue repair effect. This dual mechanism provides a synergistic effect between tissue repair and nerve regeneration, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 The figure is a schematic diagram of the preparation process of the piezoelectric / conductive dual-functional composite nanoparticles of the present invention.
[0021] Figure 2 These are actual photos of the piezoelectric / conductive bifunctional composite nanoparticles and their intermediate products prepared in the examples of the present invention, which include, from left to right: barium titanate nanoparticles, barium titanate nanoparticles coated with a tannic acid organic layer, and barium titanate nanoparticles with a graphene-like carbon shell.
[0022] Figure 3 The following are microscopic transmission electron microscope morphology photos of barium titanate nanoparticles before and after modification in the embodiment of the present invention, from left to right: pure barium titanate nanoparticles, nanoparticles with a barium titanate to tannic acid feed ratio of 1:1, nanoparticles with a barium titanate to tannic acid feed ratio of 1:4, and nanoparticles with a barium titanate to tannic acid feed ratio of 1:10.
[0023] Figure 4 These are transmission electron microscope microscopic morphology photos of the carbon shell on the surface of barium titanate nanoparticles prepared in an example of the present invention, which show, from left to right: without hydrothermal carbonization step and with hydrothermal carbonization step. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific implementation methods, but this should not be understood as the scope of the above-mentioned subject matter of the present invention being limited to the following embodiments.
[0025] A piezoelectric / conductive bifunctional composite nanoparticle with a barium titanate@graphene-like carbon layer core-shell structure, wherein the preparation method comprises the following steps: 1. Preparation of Tannic Acid Shell on Barium Titanate Nanoparticles (1) Add 100 mg of tannic acid to 100 ml of Tris-HCl buffer (pH 7.0) to obtain a 1 mg / ml tannic acid solution.
[0026] (2) Mix 100 mg of barium titanate nanoparticles and the above tannic acid solution in proportion and add them to a beaker. React with magnetic stirring at a speed of 300 rad for 12 h.
[0027] (3) The reaction solution was centrifuged at 5000 rad for 5 min. The supernatant was discarded and deionized water was added to disperse the nanoparticles.
[0028] (4) Repeat step (3) 3-5 times until the supernatant solution is transparent.
[0029] (5) The obtained nanoparticle precipitate was frozen at -20°C and freeze-dried for 24 hours to obtain barium titanate nanoparticles with a tannic acid shell.
[0030] 2. Preparation of Hydrothermal Carbon Layer on the Surface of Barium Titanate Nanoparticles (1) Add 50 mg of tannic acid to 50 ml of Tris-HCl buffer (pH 7.0) to obtain a hydrothermal solution.
[0031] (2) Add 50 mg of barium titanate nanoparticles with a tannic acid layer and the above hydrothermal solution into the lining of the hydrothermal kettle.
[0032] (3) Place the hydrothermal reactor in a vacuum drying oven and heat the reaction at 180°C for 12 hours.
[0033] (4) The reaction solution was centrifuged at 5000 rad for 5 min. After centrifugation, the supernatant was discarded and deionized water was added to disperse the nanoparticles.
[0034] (5) Repeat step (4) 3-5 times until the supernatant solution is transparent.
[0035] (6) The obtained nanoparticle precipitate was frozen at -20°C and freeze-dried for 24 hours to obtain barium titanate nanoparticles with a hydrothermal carbon shell.
[0036] 3. Preparation of graphene-like carbon layer on the surface of barium titanate nanoparticles The barium titanate nanoparticles with a hydrothermal carbon shell were placed in an atmosphere sintering furnace for argon atmosphere sintering. The basic heating curve was as follows: heating to 300°C at 2°C / min, heating to 600°C at 1°C / min, and then heating to 800°C at 2°C / min and holding for 2-4 hours. After the sintering, the particles were cooled to room temperature in the furnace.
[0037] Listed below are several best embodiments of the present invention. It should be understood that these embodiments are only for illustrative purposes and in no way limit the scope of protection of the present invention.
[0038] Example 1:
[0039] 1. Preparation of Tannic Acid Shell on Barium Titanate Nanoparticles (1) Add 100 mg of tannic acid to 100 ml of Tris-HCl buffer (pH 7.0) to obtain a 1 mg / ml tannic acid solution. (2) Add 100 mg of barium titanate nanoparticles and the above tannic acid solution to a beaker and react with a magnetic stirrer at 300 rad for 12 h. (3) Centrifuge the reaction solution at 5000 rad for 5 min. Discard the supernatant after centrifugation and add deionized water to disperse the nanoparticle precipitate. (4) Repeat step (3) 3-5 times until the supernatant of the solution is transparent. (5) Freeze the obtained nanoparticle precipitate at -20 °C and freeze-dry for 24 hours to obtain barium titanate nanoparticles with a tannic acid shell.
[0040] 2. Preparation of Hydrothermal Carbon Layer on the Surface of Barium Titanate Nanoparticles (1) Add 50 mg of tannic acid to 50 ml of Tris-HCl buffer at pH 7.0 to obtain a hydrothermal solution. (2) Add 50 mg of barium titanate nanoparticles with a tannic acid layer and the above hydrothermal solution to the inner lining of a hydrothermal reactor. (3) Place the hydrothermal reactor in a vacuum drying oven and heat at 180 °C for 12 hours. (4) Centrifuge the reaction solution at 5000 rad for 5 minutes. After centrifugation, discard the supernatant and add deionized water to disperse the nanoparticle precipitate. (5) Repeat step (4) 3-5 times until the supernatant of the solution is transparent. (6) Freeze the obtained nanoparticle precipitate at -20 °C and freeze-dry for 24 hours to obtain barium titanate nanoparticles with a hydrothermal carbon shell.
[0041] 3. Preparation of graphene-like carbon layer on the surface of barium titanate nanoparticles Place the bracket in an atmosphere sintering furnace and sinter in an argon atmosphere. The basic heating curve is as follows: heat up to 300°C at 2°C / min, heat up to 600°C at 1°C / min, and then heat up to 800°C at 2°C / min and keep warm for 2-4 hours. After the end, cool to room temperature in the furnace.
[0042] like Figure 1-Figure 3 As shown: Through the above steps, barium titanate nanoparticles with a graphene-like structure carbon layer with a thickness of 1~3nm can be obtained, and the particle size is 50-200nm. Hydrothermal carbonization and atmosphere sintering can realize the effect of converting the tannic acid layer into a graphene-like structure carbon layer, thereby realizing the composite of conductive material and piezoelectric material.
[0043] Example 2:
[0044] The method described in Example 1 is referred to, except that 400 mg of tannic acid is used, a 4 mg / ml tannic acid solution is prepared and compounded with barium titanate, and hydrothermal carbonization and atmosphere sintering are performed to obtain barium titanate nanoparticles with a graphene-like carbon layer having a thickness of 4 to 6 nm and a particle size of 50 to 200 nm. Figure 3 As shown in FIG1 , compared with Example 1, the tannic acid content is increased by 4 times, and the thickness of the final carbon layer is improved by more than 2-3 times.
[0045] Example 3:
[0046] The method described in Example 1 is referred to, except that: 1000 mg of tannic acid is used, a 10 mg / ml tannic acid solution is prepared and compounded with barium titanate, and hydrothermal carbonization and atmosphere sintering are performed respectively to obtain barium titanate nanoparticles with a graphene-like carbon layer having a thickness of 10-12 nm and a particle size of 50-200 nm. Figure 3 As shown in FIG1 , compared with Example 1, the content of tannic acid is increased by 10 times, and the thickness of the final carbon layer is improved by more than 5-6 times.
[0047] Example 4:
[0048] A 1 mg / ml tannic acid solution was prepared and compounded with barium titanate as in Example 1, and then subjected to hydrothermal carbonization and atmosphere sintering, respectively, to produce barium titanate nanoparticles having a graphene-like carbon layer with a thickness of 1 to 3 nm. Compared to Example 1, when the hydrothermal sintering temperature was set at 120°C, the proportion of the graphene-like carbon layer produced was lower than that produced in Example 1.
[0049] Example 5:
[0050] A 1 mg / ml tannic acid solution was prepared and compounded with barium titanate as in Example 1, and then subjected to hydrothermal carbonization and atmosphere sintering, respectively, to produce barium titanate nanoparticles having a graphene-like carbon layer with a thickness of 1 to 3 nm. Compared to Example 1, when the sintering temperature was set at 150°C during the hydrothermal sintering, the resulting graphene-like carbon layer had a lower proportion than that produced in Example 1, but a higher proportion than that produced in Example 4.
[0051] Example 6:
[0052] A 1 mg / ml tannic acid solution was prepared and compounded with barium titanate as in Example 1, and then subjected to hydrothermal carbonization and atmosphere sintering to produce barium titanate nanoparticles having a graphene-like carbon layer with a thickness of 1 to 3 nm. Compared to Example 1, the hydrothermal sintering time was set to 4 hours, resulting in a lower proportion of the graphene-like carbon layer than that produced in Example 1.
[0053] Example 7:
[0054] A 1 mg / ml tannic acid solution was prepared and compounded with barium titanate as in Example 1, and then subjected to hydrothermal carbonization and atmosphere sintering, respectively, to produce barium titanate nanoparticles having a graphene-like carbon layer with a thickness of 1 to 3 nm. Compared to Example 1, the hydrothermal sintering was performed for 8 hours. The resulting graphene-like carbon layer had a lower proportion than that produced in Example 1, but a higher proportion than that produced in Example 6.
[0055] Comparative Example 1:
[0056] A 10 mg / ml tannic acid solution was prepared and combined with barium titanate as in Example 1, followed by hydrothermal carbonization to produce barium titanate nanoparticles with a hydrothermal carbon layer 10-12 nm thick. Compared to Example 3, this example utilized only hydrothermal carbonization without high-temperature sintering. The resulting carbon layer exhibited a lower degree of graphitization and exhibited weaker electrical conductivity and thermal stability than a graphene-like carbon layer.
[0057] Comparative Example 2:
[0058] According to Example 1, 10 mg / ml tannic acid solution was prepared and compounded with barium titanate, and then atmosphere sintering was performed to obtain barium titanate nanoparticles with an amorphous carbon layer of 10-12 nm thickness. Compared with Example 3, this example only used high temperature atmosphere sintering without using hydrothermal carbonization technology first. The results are as follows Figure 4 As shown, the obtained carbon layer is amorphous carbon, and its conductivity is weaker than that of the graphene-like structured carbon layer.
Claims
1. A piezoelectric / conductive bifunctional composite nanoparticle with a barium titanate@graphene-like carbon layer core-shell structure, characterized in that: It consists of a barium titanate core and a graphene-like carbon shell covering its surface.
2. The composite nanoparticle according to claim 1, characterized in that The graphene-like carbon shell is prepared by polymerizing tannic acid on the surface of barium titanate nanoparticles in a neutral or alkaline environment to form an organic layer, followed by a hydrothermal carbonization and atmosphere sintering process.
3. The composite nanoparticle according to claim 1, characterized in that The particle size of the barium titanate nanoparticles ranges from 50 to 200 nm.
4. The composite nanoparticle according to claim 1, characterized in that The thickness of the graphene-like carbon shell is 1-12 nm.
5. The method for preparing composite nanoparticles according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) Preparation of barium titanate nanoparticles with tannic acid shell; (2) Hydrothermal carbonization; (3) Atmosphere sintering.
6. The preparation method according to claim 5, characterized in that The step (1) is specifically as follows: Barium titanate nanoparticles are mixed with tannic acid in a neutral or alkaline environment to form a tannic acid coating layer on the surface of the barium titanate; further, the pH value of the neutral environment is 6.8-7.4; and the concentration of the tannic acid is 0.5-2.0 mg / mL.
7. The preparation method according to claim 5, characterized in that The step (2) is specifically as follows: The barium titanate nanoparticles coated with tannic acid are placed in a hydrothermal solution at 180° C. for hydrothermal carbonization, forming a hydrothermal carbon layer on the surface of the barium titanate to obtain barium titanate nanoparticles with a hydrothermal carbon shell. Furthermore, the solution used for the hydrothermal carbonization is tannic acid in a neutral or alkaline solution, wherein the concentration of the tannic acid is the same as that of the tannic acid in step (1), and the hydrothermal carbonization reaction time is 12-24 hours.
8. The preparation method according to claim 5, characterized in that The step (3) is specifically as follows: The barium titanate nanoparticles with a hydrothermal carbon shell prepared in step (2) are sintered in a protective atmosphere or a vacuum environment to obtain piezoelectric / conductive bifunctional composite nanoparticles with a barium titanate@graphene-like carbon layer core-shell structure.
9. The preparation method according to claim 5, characterized in that The atmosphere sintering temperature is 800° C., the sintering atmosphere is nitrogen or argon, and the sintering time is 1-2 hours.
10. The use of the composite nanoparticles according to claim 1, characterized in that: The invention can be used to prepare tissue regeneration and / or nerve repair materials.