High-performance flexible bisphenol a polycarbonate piezoelectric film and preparation method thereof

Abstract

The present application relates to the technical field of nanofiber, and particularly relates to a high-performance flexible bisphenol A polycarbonate piezoelectric film and a preparation method thereof. By introducing CTAB into the spinning solution and selecting specific preparation process parameters, combined with electrospinning technology, a high-performance flexible bisphenol A polycarbonate piezoelectric film is successfully prepared. The piezoelectric film effectively improves the problem of string beads existing in the nanofiber, has controllable nanofiber structure, good fiber continuity, no bead formation, and significantly enhanced fiber film flexibility. At the same time, combined with the preparation process and test method of the piezoelectric device, the piezoelectric film is systematically characterized, and the results prove that it has excellent piezoelectric performance. It fills the research gap of BPAPC in the field of piezoelectric materials, and is expected to be applied in the fields of energy collection, self-powered sensing and the like. The preparation method is simple in operation, easy to control in condition, low in preparation cost, and conducive to realizing large-scale production.

Description

Technical Field

[0001] This invention relates to the field of nanofiber technology, and in particular to a high-performance flexible bisphenol A type polycarbonate piezoelectric film and its preparation method. Background Technology

[0002] With the rapid development of flexible electronics, wearable devices, self-powered sensing systems, and micro-energy harvesting technologies, there is an urgent need for functional materials possessing excellent flexibility, high voltage response, good environmental adaptability, and ease of processing. Piezoelectric materials, capable of directly converting mechanical energy into electrical energy, are among the ideal candidate materials for constructing such systems. Among numerous piezoelectric materials, polymer piezoelectric materials have attracted considerable attention due to their inherent flexibility, ease of processing into films, low density, and good fatigue resistance, making them particularly suitable for flexible, wearable, and complex surface-adhering applications.

[0003] Electrospinning technology, with its ability to efficiently prepare nanofiber membranes with high specific surface area, tunable porosity, and good flexibility, has become a key material preparation platform for developing next-generation flexible polymer piezoelectric devices (such as nanogenerators and self-powered sensors). In this process, a polymer solution or melt forms a jet under a high-voltage electric field. After stretching, refining, and solvent evaporation, it is finally deposited as micro / nanoscale fibers. This process not only enables the nanostructuring of materials, but the accompanying high-electric-field stretching and rapid curing kinetics also effectively induce polymer molecular chain orientation and promote the ordered arrangement of dipole moments, thereby directly endowing the fiber membrane with a significant piezoelectric response without complex post-processing.

[0004] Currently, the sources of polymer materials suitable for electrospinning and possessing well-defined piezoelectric properties are extremely limited. Polyvinylidene fluoride (PVDF) and its copolymers are the most widely studied and applied systems, with their piezoelectricity stemming from the ordered arrangement of -CF2 dipoles (primarily β-crystal). However, PVDF-based materials suffer from a narrow operating temperature window and their piezoelectric properties depend on complex polarization processes or copolymerization / composite modification, limiting their application in a wider range of environments. Besides PVDF, materials such as polyacrylonitrile, odd-numbered nylon, poly-L-lactic acid, and some polyimides have also been shown to possess piezoelectric potential, but each faces different challenges: polyacrylonitrile suffers from poor spinning solution stability and insufficient piezoelectric stability; odd-numbered nylon and other materials have high spinnability and large-scale production costs; and the piezoelectric properties of many high-performance engineering plastics have long remained unexplored or unstudied systematically. This limitation and singularity of material systems severely restricts the development and application innovation of high-performance, multifunctional, and customizable electrospun piezoelectric nanofiber membranes.

[0005] Bisphenol A type polycarbonate (BPAPC) possesses excellent mechanical properties, thermal stability, and transparency, and has been widely used in electronics, automotive, and medical fields. During the electrospinning preparation of BPAPC nanofibers, the rapid solvent evaporation rate and the quick solidification of the jet surface layer cause surface tension to overcome electrostatic forces, resulting in insufficient stretching of the spinning jet and the formation of beaded fibers. This beaded structure affects the uniformity of fiber morphology and the mechanical toughness of the film, limiting its reliability and durability in practical flexible devices. Existing research on electrospun BPAPC nanofibers mainly focuses on their applications in filtration, reinforcement, and sensing substrates; there is no systematic research confirming its potential as a high-performance piezoelectric material, and there is a lack of preparation methods optimized for its piezoelectric properties. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the related art. Therefore, the first objective of the present invention is to provide a method for preparing a high-performance flexible bisphenol A type polycarbonate piezoelectric film; the second objective of the present invention is to provide a high-performance flexible bisphenol A type polycarbonate piezoelectric film.

[0007] To achieve the first objective, the technical solution adopted by this invention is as follows:

[0008] A method for preparing a high-performance flexible bisphenol A type polycarbonate piezoelectric film includes the following steps:

[0009] S100. Dissolve the polymer in an organic solvent to obtain a polymer solution;

[0010] The polymer is selected from BPAPC, and the mass concentration of the polymer solution is 15% to 20%.

[0011] S200. Add an additive to the polymer solution and stir to evenly disperse the additive in the polymer solution to obtain a spinning solution containing the additive.

[0012] The additive is selected from cetyl trimethyl ammonium bromide (CTAB), and the mass concentration of the additive is 0.2% to 0.8%.

[0013] S300. Using the spinning solution as raw material, a high-performance flexible bisphenol A type polycarbonate piezoelectric film formed by nanofibers is prepared by electrospinning technology.

[0014] Currently, when preparing BPAPC nanofibers using electrospinning technology, beading often occurs, and the fiber membrane lacks toughness, making it difficult to apply on a large scale in sensing and power generation fields requiring continuous operation. Therefore, effectively improving fiber morphology and enhancing the spinnability of BPAPC materials has become an urgent problem to be solved. This invention improves the morphology of the prepared piezoelectric film containing nanofibers by adding CTAB to the polymer solution and selecting specific preparation process parameters, thereby obtaining a uniform and bead-free nanofiber membrane and improving the piezoelectric properties of the nanofiber membrane. As a typical cationic surfactant, CTAB improves the beading effect of BPAPC electrospinning by controlling the physicochemical properties of the solution and optimizing the jet stretching and solidification balance, specifically addressing the core issues of bead formation (insufficient molecular chain entanglement, imbalance between electric field and surface tension, and asynchronous solvent evaporation). The specific mechanism of action is mainly reflected in the following aspects:

[0015] I. Enhancing Solution Conductivity and Strengthening the Electric Field Tensioning Effect: One of the key factors contributing to bead formation is the low conductivity of the BPAPC solution, resulting in insufficient charge density carried by the jet, and the electric field tensile force cannot adequately overcome surface tension. CTAB, as an ionic surfactant, ionizes into trimethylammonium cations N(CH3)3 upon dissolution. + and bromide ions Br - This significantly increases the ion concentration and conductivity of the solution. The increased conductivity allows the jet to carry more charge in the high-voltage electric field, and the Coulomb repulsion is significantly enhanced. On the one hand, this strengthens the jet's stretching and refining effect, preventing the formation of droplets due to insufficient stretching; on the other hand, it improves the axial stability of the jet, reducing bead formation caused by jet fluctuations and breakage.

[0016] II. Reducing Solution Surface Tension and Suppressing Jet Contraction Tendency: The high surface tension of BPAPC spinning solutions (such as tetrahydrofuran systems) causes the jet to exhibit a strong tendency to contract, easily agglomerating into beads. CTAB has a typical amphiphilic molecular structure (long-chain hydrophobic alkyl groups and hydrophilic cationic head groups), and its molecules spontaneously adsorb at the gas-liquid interface of the solution, with the hydrophobic chains facing the air phase and the hydrophilic heads facing the solution phase. This directional alignment significantly reduces the solution surface tension. The reduction in surface tension weakens the jet's contraction driving force, making it easier for the jet to maintain a continuous filamentary shape during stretching, rather than contracting into discrete droplets.

[0017] Third, it promotes molecular chain entanglement and enhances solution viscoelasticity. Insufficient solution viscoelasticity and weak molecular chain entanglement are the core internal factors for bead formation. CTAB can enhance BPAPC molecular chain entanglement through two pathways: First, hydrophobic interaction, where the hexadecyl long chain of CTAB hydrophobically associates with the hydrophobic region of the aromatic ring in the BPAPC molecule, making it easier for the BPAPC molecular chains to aggregate and form a continuous elastic network; second, electrostatic adsorption and steric hindrance effects, where the cationic head groups of ionized CTAB can be adsorbed onto the polar sites (such as ether bonds and carbonyl groups) of the BPAPC molecular chain through electrostatic interaction, forming a bridging effect and reducing molecular chain slippage. At the same time, the adsorbed CTAB molecules can form steric hindrance, further inhibiting molecular chain de-entanglement.

[0018] IV. Optimize the solvent evaporation rhythm and synchronize jet stretching and curing. Asynchronous jet stretching and solvent evaporation (e.g., slow solvent evaporation causing the jet to remain in a fluid state for an extended period) can lead to bead formation. CTAB's interfacial adsorption properties can indirectly regulate the solvent evaporation rate: on one hand, the adsorption layer formed by CTAB on the solution surface can moderately reduce the evaporation resistance of high-boiling-point solvents (such as tetrahydrofuran), accelerating solvent evaporation; on the other hand, its molecular chains can form weak interactions with solvent molecules, preventing premature solidification and brittle fracture of the jet due to rapid solvent evaporation. This regulatory effect allows for a better match between the jet stretching process and the solvent curing process, reducing jet shrinkage and bead formation caused by delayed curing, or jet breakage and droplet formation caused by excessively rapid curing. Furthermore, CTAB can improve solution uniformity, avoiding differences in evaporation rates caused by local solvent imbalances, further reducing the probability of bead formation.

[0019] Preferably, in step S100, the organic solvent is selected from a mixed solvent composed of N,N-dimethylformamide and tetrahydrofuran.

[0020] Preferably, the mass ratio of N,N-dimethylformamide (DMF) to tetrahydrofuran (THF) is 2:3 to 3:2.

[0021] Preferably, the mass ratio of DMF to THF is 1:1.

[0022] Preferably, in step S200, the mass concentration of the additive is 0.4% to 0.7%.

[0023] Preferably, the mass concentration of the additive is 0.5% to 0.6%.

[0024] Preferably, in step S300, the process parameters for electrospinning are as follows:

[0025] The spinning voltage is 15kV~25kV, the solution propulsion rate is 0.3mL / h~0.8mL / h, the spinning distance is 10cm~15cm, and the collecting roller speed is 800rpm~1200rpm.

[0026] Preferably, the surface of the collecting roller is covered with aluminum foil, the thickness of which is 15μm to 25μm.

[0027] Preferably, in step S300, the thickness of the high-performance flexible bisphenol A type polycarbonate piezoelectric film is 10 to 100 μm.

[0028] To achieve the second objective, the technical solution adopted by this invention is as follows:

[0029] A high-performance flexible bisphenol A type polycarbonate piezoelectric film is prepared using any one of the above-described methods for preparing high-performance flexible bisphenol A type polycarbonate piezoelectric films.

[0030] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0031] This invention provides a method for preparing high-performance flexible bisphenol A (BPA) type polycarbonate piezoelectric films. By introducing a specific additive, hexadecyltrimethylammonium bromide (CTAB), into the spinning solution and selecting specific process parameters, combined with electrospinning technology, a high-performance flexible BPA type polycarbonate piezoelectric film was successfully prepared. This piezoelectric film effectively improves the problem of beading in BPAPC nanofibers prepared by previous electrospinning processes, possessing a controllable nanofiber structure, good fiber continuity, no bead formation, and significantly enhanced fiber membrane flexibility.

[0032] Simultaneously, this invention combines the fabrication process and testing methods of piezoelectric sensor devices to systematically characterize high-performance flexible bisphenol A (BPA) type polycarbonate (PCP) piezoelectric films. The results confirm their excellent piezoelectric properties, capable of generating an open-circuit voltage as high as 250.4 V and a short-circuit current of 142.8 μA. The output performance and piezoelectric properties are significantly improved compared to nanofibers with other additives (such as BMIM·BF4) or without additives. The piezoelectric film provided by this invention fills a research gap in BPAPC piezoelectric materials and is expected to find applications in energy harvesting, self-powered sensing, and other fields.

[0033] The preparation method provided by this invention is simple to operate, the conditions are easy to control, and the preparation cost is low, which is conducive to achieving large-scale production.

[0034] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0035] Figure 1 This is a surface morphology diagram of the nanofiber membranes obtained by observing Examples 1 to 7, Comparative Example 4 and Comparative Example 8 using an electron microscope, provided in Example 1 of the present invention.

[0036] Figure 2 This is a graph showing the relationship between different concentrations of additives and peak voltage and peak current provided in Example 2 of this invention.

[0037] Figure 3 This is the piezoelectric performance test result of the piezoelectric device made based on the nanofiber membrane prepared in Example 4 and Comparative Example 8 provided in Test Example 2 of the present invention.

[0038] Figure 4 This is the test result of the piezoelectric constant of the piezoelectric device prepared based on different nanofiber membranes provided in Test Example 2 of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention, but cannot be used to limit the scope of this invention.

[0040] In the following embodiments, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available, unless otherwise specified, and are carried out in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions.

[0041] Example 1

[0042] The process for preparing high-performance flexible bisphenol A type polycarbonate piezoelectric films is as follows:

[0043] 1. Prepare the spinning solution.

[0044] BPAPC (1.7 g) was dissolved in DMF (4.15 g) and THF (4.15 g) to form a mixed solvent. The solution was stirred continuously in an oil bath at 60 °C for 12 h until BPAPC was completely dissolved, resulting in a BPAPC solution with a concentration of 17%. Subsequently, CTAB (3.4 mg, corresponding to a mass concentration of 0.2%) was added to the BPAPC solution and stirred thoroughly for 2 h to obtain a spinning solution containing CTAB and BPAPC.

[0045] II. Preparation of high-performance flexible bisphenol A type polycarbonate piezoelectric films using electrospinning technology.

[0046] The spinning solution obtained above was loaded into a 10 mL syringe, and then the syringe was placed on the pusher of the high voltage electrospinning device. Spinning was carried out using needle electrospinning technology, with a roller collector covered with aluminum foil (about 20 μm thick) as the fiber receiving device.

[0047] The process parameters for electrospinning are set as follows:

[0048] The spinning voltage was 20 kV, the solution feed rate was 0.5 mL / h, the distance between the collecting roller and the needle electrode was 12 cm, and the collecting roller rotation speed was 1000 rpm. During the spinning process, the relative humidity was maintained at 30%–40%, and the spinning temperature was 15℃–30℃. The propeller reciprocated, and the polymer fibers were uniformly sprayed onto the aluminum foil. The spinning time was 2.5 h, resulting in a nanofiber membrane with a thickness of approximately 70 μm, namely a high-performance flexible bisphenol A type polycarbonate piezoelectric film.

[0049] The thickness of the fiber membrane is controlled by the spinning time, as follows: by controlling the effective spinning time of the needle electrode relative to a specific position on the collecting roller, the deposition thickness of the fiber membrane at that position can be directly controlled. The thickness (T) is proportional to the effective spinning time (t), satisfying T=k·t, where k is the deposition rate coefficient (28μm / h). By controlling the effective spinning time, the thickness of the nanofiber membrane can be controlled.

[0050] Example 2

[0051] Except for replacing the amount of CTAB added with 5.1 mg (corresponding to a mass concentration of 0.3%), the rest of the process is the same as in Example 1.

[0052] Example 3

[0053] Except for replacing the amount of CTAB added with 6.8 mg (corresponding to a mass concentration of 0.4%), the rest of the process is the same as in Example 1.

[0054] Example 4

[0055] Except for replacing the amount of CTAB added with 8.5 mg (corresponding to a mass concentration of 0.5%), the rest of the process is the same as in Example 1.

[0056] Example 5

[0057] Except for replacing the amount of CTAB added with 10.2 mg (corresponding to a mass concentration of 0.6%), the rest of the process is the same as in Example 1.

[0058] Example 6

[0059] Except for replacing the amount of CTAB added with 11.9 mg (corresponding to a mass concentration of 0.7%), the rest of the process is the same as in Example 1.

[0060] Example 7

[0061] Except for replacing the amount of CTAB added with 13.6 mg (corresponding to a mass concentration of 0.8%), the rest of the process is the same as in Example 1.

[0062] Comparative Example 1

[0063] Except for replacing CTAB with BMIM·BF4, the rest of the process is the same as in Example 1.

[0064] Comparative Example 2

[0065] Except for replacing the amount of BMIM·BF4 added with 5.1 mg (corresponding to a mass concentration of 0.3%), the rest of the process is the same as in Comparative Example 1.

[0066] Comparative Example 3

[0067] Except for replacing the amount of BMIM·BF4 added with 6.8 mg (corresponding to a mass concentration of 0.4%), the rest of the process is the same as in Comparative Example 1.

[0068] Comparative Example 4

[0069] Except for replacing the amount of BMIM·BF4 added with 8.5 mg (corresponding to a mass concentration of 0.5%), the rest of the process is the same as in Comparative Example 1.

[0070] Comparative Example 5

[0071] Except for replacing the amount of BMIM·BF4 added with 10.2 mg (corresponding to a mass concentration of 0.6%), the rest of the process is the same as in Comparative Example 1.

[0072] Comparative Example 6

[0073] Except for replacing the amount of BMIM·BF4 added with 11.9 mg (corresponding to a mass concentration of 0.7%), the rest of the process is the same as in Comparative Example 1.

[0074] Comparative Example 7

[0075] Except for replacing the amount of BMIM·BF4 added with 13.6 mg (corresponding to a mass concentration of 0.8%), the rest of the process is the same as in Comparative Example 1.

[0076] Comparative Example 8

[0077] Except for not adding CTAB, the rest of the process is the same as in Example 1.

[0078] Test Example 1

[0079] The surface morphology of the nanofiber membranes provided in the examples and comparative examples was observed using an electron microscope, and the results are as follows: Figure 1 As shown in the figure, the nanofibers containing the additive CTAB (Examples 1 to 7) exhibit a uniform and dense interwoven network structure with fine fiber diameters and uniform distribution. There are no obvious defects such as beading, agglomeration, or uneven thickness, and it is a regular fiber membrane structure. The nanofibers containing the additive BMIM·BF4 (Comparative Example 4) do not show obvious agglomeration or uneven thickness. The nanofibers without additives (Comparative Example 8) show obvious differences in fiber morphology compared to the fibers with additives, and obvious beading and uneven fiber thickness are observed on the nanofibers.

[0080] Test Example 2

[0081] The piezoelectric properties of the nanofiber membranes prepared in the aforementioned examples and comparative examples were tested, and the process is as follows:

[0082] I. Fabrication of piezoelectric devices.

[0083] The prepared BPAPC nanofiber membrane was cut into 2cm×2cm square samples and sandwiched between two clean copper foil electrodes to form a basic piezoelectric unit. Subsequently, the basic piezoelectric unit was encapsulated around the perimeter with a polyethylene terephthalate (PET) film to obtain a piezoelectric device based on flexible BPAPC nanofibers.

[0084] II. Piezoelectric performance test.

[0085] A mechanical excitation-electrical signal synchronous acquisition system was used for testing, and all tests were conducted at room temperature. The piezoelectric device was fixed on the test platform, and a periodic compressive force was applied to the device surface by a microcomputer-controlled linear actuator. The standard test conditions were set as follows: applied compressive force of 10N and operating frequency of 1Hz. The open-circuit voltage signal between the two electrodes of the device was directly measured and recorded using an oscilloscope, and the external circuit current signal flowing through the device was measured using an electrochemical workstation in short-circuit mode. The peak open-circuit voltage and peak short-circuit current were extracted from the recorded periodic signals as key indicators for evaluating the piezoelectric output performance. The test results for samples provided in different embodiments and comparative examples are shown in the table below:

[0086]

[0087] The relationship curves between different concentrations of additives and peak voltage and peak current, such as... Figure 2 As shown;

[0088] Figure A shows the relationship between the concentration of the additive CTAB and the peak voltage. It can be seen from the figure that as the concentration of CTAB increases, the peak voltage first rises significantly (the peak voltage is close to 250V when the concentration is about 0.5%), and then gradually decreases. The peak voltage of the nanofiber membrane with added CTAB (the nanofiber membranes provided in Examples 1 to 7) is higher than that of the nanofiber without additive (Comparative Example 8).

[0089] Figure B shows the relationship between the concentration of the additive CTAB and the peak current. From the figure, it can be seen that as the concentration of CTAB increases, the peak current first increases significantly (the peak current is close to 150 μA when the concentration is about 0.5%), and then gradually decreases. The peak current of the nanofiber membrane with added CTAB (the nanofiber membranes provided in Examples 1 to 7) is higher than that of the nanofiber without additive (Comparative Example 8).

[0090] Figure C shows the relationship between the concentration of additive BMIM·BF4 and the peak voltage. From the figure, it can be seen that as the concentration of BMIM·BF4 changes, the peak voltage remains at a low level of about 50V, which is much lower than the 81V without additive. The peak voltage of the nanofiber membrane with added BMIM·BF4 (the nanofiber membranes provided by Comparative Examples 1 to 7) is lower than that of the nanofiber without additive (Comparative Example 8), indicating that BMIM·BF4 will reduce the peak voltage of nanofiber.

[0091] Figure D shows the relationship between the concentration of additive BMIM·BF4 and the peak current. From the figure, it can be seen that as the concentration of BMIM·BF4 increases, the peak current first rises slightly (reaching about 97 μA at around 0.5%), then gradually decreases, and finally falls back to about 50 μA. The peak current of the nanofiber membranes with added BMIM·BF4 (the nanofiber membranes provided by Comparative Examples 1 to 7) is lower than that of the nanofiber membranes without additives (Comparative Example 8).

[0092] Piezoelectric devices were prepared using the sample with the best electrical performance from the examples (Example 4, CTAB concentration of 0.5%) and additive-free nanofibers (Comparative Example 8), and their piezoelectric properties were tested. The results are as follows: Figure 3 As shown;

[0093] Figure A shows the open-circuit voltage output curve of the piezoelectric device prepared based on the nanofiber membrane provided in Example 4.

[0094] Figure B shows the short-circuit current output curve of the piezoelectric device prepared based on the nanofiber membrane provided in Example 4;

[0095] Figure C shows the open-circuit voltage output curve of the piezoelectric device fabricated based on the nanofiber membrane provided in Comparative Example 8.

[0096] Figure D shows the short-circuit current output curve of the piezoelectric device fabricated based on the nanofiber membrane provided in Comparative Example 8.

[0097] The piezoelectric constants of piezoelectric devices fabricated based on different nanofiber membranes were measured, and the results are as follows: Figure 4 As shown;

[0098] Figure A shows the relationship between CTAB concentration and piezoelectric constant (d). 33 The graph shows the relationship between d and CTAB concentration. From this graph, we can see that as the CTAB concentration increases, d... 33 The concentration initially increases significantly, reaching a peak in the 0.5%–0.6% concentration range (close to 80 pC / N, much higher than the 44.5 pC / N without additives); then it decreases rapidly, dropping to around 20 pC / N at 0.8%. This result indicates that CTAB at a suitable concentration of 0.3%–0.7% can significantly improve the piezoelectric properties of nanofibers, but excessively high or low concentrations are detrimental to the improvement of piezoelectric properties.

[0099] Figure B shows the relationship between BMIM·BF4 concentration and piezoelectric constant. From this figure, it can be seen that BMIM·BF4 has a very weak effect on improving the piezoelectric properties of nanofibers, and it hardly exceeds the level of no additives.

[0100] In summary, the introduction of additives not only optimizes the morphology of the fiber membrane, but their type and concentration also directly affect the piezoelectric output of the final fiber membrane. This invention achieves a synergistic effect of fiber morphology optimization and piezoelectric performance enhancement by introducing the additive hexadecyltrimethylammonium bromide (CTAB). Furthermore, by adjusting the additive concentration, the voltage and current output of the final piezoelectric device can be effectively and controllably adjusted within a certain range. This provides a convenient control method to meet the specific output performance requirements of different application scenarios, demonstrating good design flexibility and customizability.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing high performance flexible bisphenol-A polycarbonate piezoelectric thin films, characterized by, The method comprises the following steps: S100, dissolving a polymer in an organic solvent to obtain a polymer solution; The polymer is selected from bisphenol A polycarbonate, and the mass concentration of the polymer solution is 15%-20%; The organic solvent is selected from a mixed solvent of N,N-dimethylformamide and tetrahydrofuran; S200, adding an additive to the polymer solution, and stirring to uniformly disperse the additive in the polymer solution to obtain a spinning solution containing the additive; The additive is selected from cetyltrimethylammonium bromide, and the mass concentration of the additive is 0.2%-0.8%; S300, using the spinning solution as raw material, and using electrospinning technology to prepare a high-performance flexible bisphenol A polycarbonate piezoelectric film formed by nanofibers; The process parameters of the electrospinning technology are as follows: The spinning voltage is 15 kV-25 kV, the solution propulsion rate is 0.3 mL / h-0.8 mL / h, the spinning distance is 10 cm-15 cm, and the collection roller speed is 800 rpm-1200 rpm; During the spinning process, the relative humidity of the environment is maintained at 30%-40%, and the spinning temperature is 15°C-30°C.

2. The method for preparing a high-performance flexible bisphenol A type polycarbonate piezoelectric film as described in claim 1, characterized in that, The mass ratio of N,N-dimethylformamide to tetrahydrofuran is 2:3-3:

2.

3. The method for preparing a high-performance flexible bisphenol A type polycarbonate piezoelectric film as described in claim 2, characterized in that, The mass ratio of N,N-dimethylformamide to tetrahydrofuran is 1:

1.

4. The method for preparing a high-performance flexible bisphenol A type polycarbonate piezoelectric film as described in claim 1, characterized in that, In step S200, the mass concentration of the additive is 0.4%-0.7%.

5. The method for preparing a high-performance flexible bisphenol A type polycarbonate piezoelectric film as described in claim 4, characterized in that, The mass concentration of the additive is 0.5%-0.6%.

6. The method for preparing a high-performance flexible bisphenol A type polycarbonate piezoelectric film as described in claim 5, characterized in that, The surface of the collection roller is covered with an aluminum foil, and the thickness of the aluminum foil is 15 μm-25 μm.

7. The method of claim 1, wherein the high performance flexible bisphenol-A polycarbonate piezoelectric film is prepared by the steps of: a) providing a solution of bisphenol-A polycarbonate in a solvent; b) coating the solution on a substrate; c) drying the coated solution; d) removing the solvent; and e) annealing the dried coated solution. In step S300, the thickness of the high-performance flexible bisphenol A polycarbonate piezoelectric film is 10-100 μm.

8. A high performance flexible bisphenol-A polycarbonate piezoelectric film characterized by, The high-performance flexible bisphenol A polycarbonate piezoelectric film is prepared by using the preparation method of any one of claims 1-7.

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