Preparation method of organic-inorganic ferroelectric polymer composite film

Abstract

The application discloses a preparation method of an organic-inorganic ferroelectric polymer composite film. The method takes a graphene / copper high-index surface with one-dimensional periodic potential as a substrate, uniformly dissolves poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) powder in a tetrahydrofuran organic solvent, adds ground monocrystal lead titanate (PbTiO3) mesoporous material, takes a proper amount of solution after sufficient stirring, spin coats the solution on the substrate, and performs vacuum drying and annealing treatment to obtain the organic-inorganic ferroelectric polymer composite film. The composite film prepared by the method has good orientation and exhibits excellent ferroelectric performance, and has a wide application prospect in flexible transducer devices, sensor devices and ferroelectric memory devices.

Description

Technical Field

[0001] This invention relates to the field of organic-inorganic ferroelectric composite materials, and more specifically to a method for preparing an organic-inorganic ferroelectric polymer composite film. Background Technology

[0002] Ferroelectric materials exhibit rich physicochemical properties and have attracted widespread attention in fields such as sensing, energy storage, electronics, catalysis, and energy. In practical device applications, such as smart sensors and medical imaging devices, the sensing surface is often curved to better receive signals, which places high demands on the design of flexible sensing materials. Among them, vinylidene fluoride-trifluoroethylene copolymer (P(VDF-TrFE)) has become one of the materials with great potential to simultaneously meet the requirements of high device performance and flexibility due to its excellent flexibility, corrosion resistance, low acoustic impedance, and the best piezoelectric properties among polymeric piezoelectric materials, showing great application potential. However, organic ferroelectric materials are usually limited by poor crystallinity, disorder, and certain performance gaps compared to inorganic materials. Therefore, the preparation of organic-inorganic composite ferroelectric materials has become a research hotspot in this field, which can effectively improve ferroelectric performance and expand device applications.

[0003] This study addresses the shortcomings of current ferroelectric composite materials, which typically combine disordered ferroelectric polymers with polycrystalline ferroelectric ceramics and fibers. The aim is to find a simple and effective method for preparing novel, highly oriented organic-inorganic ferroelectric polymer composite films, which is expected to further improve functionality. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for preparing organic-inorganic ferroelectric polymer composite films.

[0005] The objective of this invention is achieved through the following technical solution: a method for preparing an organic-inorganic ferroelectric polymer composite film, comprising the following steps:

[0006] 1) Dissolve 0.47-4.44g of P(VDF-TrFE) powder in 10-20ml of tetrahydrofuran and stir magnetically to form a homogeneous solution;

[0007] 2) Add the ground single-crystal PbTiO3 mesoporous material powder to the homogeneous solution prepared in step 1), wherein the mass ratio of the single-crystal PbTiO3 mesoporous material powder to P(VDF-TrFE) powder is 5-20:100, and stir magnetically to obtain a mixed solution.

[0008] 3) Take the mixed solution obtained in step 2) and drop it onto the graphene / copper high index crystal surface substrate, and spin coat it at a speed of 500-1000 rpm for 3-10 s, and then spin coat it at a speed of 1500-3000 rpm for 30-60 s.

[0009] 4) Finally, the spin-coated substrate is subjected to vacuum annealing to obtain an organic-inorganic ferroelectric polymer composite film.

[0010] Furthermore, the graphene / copper high index crystal plane substrate is a graphene / copper (122) substrate, a graphene / copper (431) substrate, or a graphene / copper (311) substrate.

[0011] Furthermore, the purity of the tetrahydrofuran is not lower than that of analytical grade.

[0012] Furthermore, the annealing temperature is 150-180℃, and the annealing time is 2-4 hours.

[0013] The beneficial effects of this invention are: the preparation process is simple and easy to control; the resulting organic-inorganic ferroelectric polymer composite film exhibits a large-area textured arrangement, unlike the ordinary crystalline state of P(VDF-TrFE) films; and the single-crystal lead titanate (PbTiO3) inorganic ferroelectric material is well coated within the organic film without damaging the orientation structure. Ferroelectric performance testing revealed that when the mass of PbTiO3 added was 20% of the P(VDF-TrFE) powder, the ferroelectric remanent polarization reached 12 μC / cm. 2 Compared to pure organic films, the ferroelectric properties of the composite film were improved by about 33%, showing a significant enhancement. Extensive experiments revealed that the highly oriented structure and improved ferroelectric properties of this organic-inorganic composite film stem from the electrostatic force of the one-dimensional periodic potential of the graphene / copper high-index surface, and the inductive effect of the polarization exposed near the mesopores of single-crystal PbTiO3 on the P(VDF-TrFE) polymer chains. Attached Figure Description

[0014] Figure 1 This is a SEM image of the organic-inorganic ferroelectric polymer composite film prepared in Example 1;

[0015] Figure 2 These are morphology images of organic-inorganic ferroelectric polymer composite films grown on ITO glass substrates under the same experimental conditions in a normal crystalline state.

[0016] Figure 3 This is a comparison diagram of the hysteresis loops of the organic-inorganic ferroelectric polymer composite film and the pure oriented P(VDF-TrFE) film prepared in Example 1;

[0017] Figure 4 This is a comparison diagram of the hysteresis loops of the organic-inorganic ferroelectric polymer composite film and the pure oriented P (VDF-TrFE) film prepared in Example 2. Detailed Implementation

[0018] The technical solution of the present invention will be further illustrated below with reference to the embodiments.

[0019] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the single-crystal PbTiO3 mesoporous material can be prepared according to the method shown in the paper "Ren, Z., et al. Mesopores induced zero thermal expansion in single-crystal ferroelectrics." Nature Communications 9, Article number: 1638 (2018)"; other reagents and materials, unless otherwise specified, can be obtained commercially.

[0020] Example 1

[0021] A method for preparing an organic-inorganic ferroelectric polymer composite film includes the following steps:

[0022] 1) Dissolve 1.973g of P(VDF-TrFE) powder in 20ml of tetrahydrofuran and stir magnetically to form a homogeneous solution with a mass fraction of 10%;

[0023] 2) Add 0.395g of the ground single-crystal PbTiO3 mesoporous material powder to the homogeneous solution prepared in step 1), and further stir magnetically to obtain a mixed solution;

[0024] 3) Take the mixed solution obtained in step 2) and drop it onto the graphene / copper (122) substrate. Place it on a spin coater for spin coating. First spin coat at 1000 rpm for 3s, then spin coat at 3000 rpm for 30s. The surface of the graphene / copper (122) substrate has a one-dimensional periodic potential.

[0025] 4) Finally, place the spin-coated substrate into a vacuum drying oven and anneal at 180°C for 2 hours to obtain an organic-inorganic ferroelectric polymer composite film.

[0026] The SEM image of the organic-inorganic ferroelectric polymer composite film prepared by the above method is shown below. Figure 1As shown, the composite film exhibits a large-area oriented structure, and the ground single-crystal PbTiO3 mesoporous material is essentially encapsulated within the film. The organic P(VDF-TrFE) and inorganic PbTiO3 materials show good interfacial compatibility, and the film shows no obvious cracks. For comparison, SEM images of the organic-inorganic ferroelectric polymer composite film prepared on an ITO glass substrate under the same experimental parameters are shown below. Figure 2 As shown; from Figure 2 As can be seen, the P(VDF-TrFE) film exhibits a disordered, ordinary crystalline state, and PbTiO3 mesoporous material particles can be observed encapsulated within it; through... Figure 1 and Figure 2 The comparison shows that the one-dimensional periodic potential has an effective regulating effect on the preparation of oriented organic-inorganic composite films. Experiments demonstrate that the oriented composite films exhibit superior ferroelectric properties compared to composite films with ordinary disordered structures.

[0027] Figure 3 This is a comparison of the hysteresis loops of the organic-inorganic ferroelectric polymer composite film prepared in Example 1 and the pure oriented P(VDF-TrFE) film. Figure 3 As can be seen, the organic-inorganic ferroelectric polymer composite film obtained in this embodiment exhibits significantly improved ferroelectric properties compared to the purely oriented P(VDF-TrFE) film. The saturated ferroelectric polarization of the organic-inorganic ferroelectric polymer composite film reaches 17.5 μC / cm. 2 This represents an improvement of approximately 45% compared to purely oriented P(VDF-TrFE) films. The ferroelectric remanent polarization of the organic-inorganic ferroelectric polymer composite film reaches 12 μC / cm. 2 It improves upon pure-oriented P(VDF-TrFE) films by about 33%.

[0028] Example 2

[0029] A method for preparing an organic-inorganic ferroelectric polymer composite film includes the following steps:

[0030] 1) Dissolve 1.973g of P(VDF-TrFE) powder in 20ml of tetrahydrofuran and stir magnetically to form a homogeneous solution with a mass fraction of 10%;

[0031] 2) Add 0.197g of the ground single-crystal PbTiO3 mesoporous material powder to the homogeneous solution prepared in step 1), and further stir magnetically to obtain a mixed solution;

[0032] 3) Take the mixed solution obtained in step 2) and drop it onto the graphene / copper (122) substrate. Place it on a spin coater for spin coating. First spin coat at 1000 rpm for 3s, then spin coat at 3000 rpm for 30s. The surface of the graphene / copper (122) substrate has a one-dimensional periodic potential.

[0033] 4) Finally, the spin-coated substrate is placed in a vacuum drying oven and annealed at 180°C for 2 hours to obtain an organic-inorganic ferroelectric polymer composite film.

[0034] Figure 4 This is a comparison of the hysteresis loops of the organic-inorganic ferroelectric polymer composite film prepared in Example 2 and the pure oriented P(VDF-TrFE) film. Figure 4 As can be seen, the organic-inorganic ferroelectric polymer composite film obtained in this embodiment exhibits significantly improved ferroelectric properties compared to the pure oriented P(VDF-TrFE) film. The saturated ferroelectric polarization of the organic-inorganic ferroelectric polymer composite film reaches 13.9 μC / cm. 2 This represents an improvement of approximately 20% compared to purely oriented P(VDF-TrFE) films. The ferroelectric remanent polarization of the organic-inorganic ferroelectric polymer composite film reaches 10.4 μC / cm. 2 It improves upon pure-oriented P(VDF-TrFE) films by about 15%.

[0035] Example 3

[0036] A method for preparing an organic-inorganic ferroelectric polymer composite film includes the following steps:

[0037] 1) Dissolve 0.47g of P(VDF-TrFE) powder in 10ml of tetrahydrofuran and stir magnetically to form a homogeneous solution;

[0038] 2) Add 0.0235g of the ground single-crystal PbTiO3 mesoporous material powder to the homogeneous solution prepared in step 1), and further stir magnetically to obtain a mixed solution;

[0039] 3) Take the mixed solution obtained in step 2) and drop it onto the graphene / copper (122) substrate. Place it on a spin coater for spin coating. First spin coat at 1000 rpm for 3s, then spin coat at 3000 rpm for 30s. The surface of the graphene / copper (122) substrate has a one-dimensional periodic potential.

[0040] 4) Finally, the spin-coated substrate is placed in a vacuum drying oven and annealed at 180°C for 2 hours to obtain an organic-inorganic ferroelectric polymer composite film.

[0041] Example 4

[0042] A method for preparing an organic-inorganic ferroelectric polymer composite film includes the following steps:

[0043] 1) Dissolve 4.44g of P(VDF-TrFE) powder in 10ml of tetrahydrofuran and stir magnetically to form a homogeneous solution;

[0044] 2) Add 0.888g of the ground single-crystal PbTiO3 mesoporous material powder to the homogeneous solution prepared in step 1), and further stir magnetically to obtain a mixed solution;

[0045] 3) Take the mixed solution obtained in step 2) and drop it onto the graphene / copper (122) substrate. Place it on a spin coater for spin coating. First spin coat at 1000 rpm for 3s, then spin coat at 3000 rpm for 30s. The surface of the graphene / copper (122) substrate has a one-dimensional periodic potential.

[0046] 4) Finally, the spin-coated substrate is placed in a vacuum drying oven and annealed at 180°C for 2 hours to obtain an organic-inorganic ferroelectric polymer composite film.

[0047] The organic-inorganic ferroelectric polymer composite films prepared in Examples 3 and 4 showed significantly improved ferroelectric properties compared to the pure oriented P(VDF-TrFE) films.

Claims

1. A method for preparing an organic-inorganic ferroelectric polymer composite film, characterized in that, Includes the following steps: 1) Dissolve 0.47-4.44 g of P(VDF-TrFE) powder in 10-20 mL of tetrahydrofuran and stir magnetically to form a homogeneous solution; 2) Add the ground single-crystal PbTiO3 mesoporous material powder to the homogeneous solution prepared in step 1), wherein the mass ratio of the single-crystal PbTiO3 mesoporous material powder to P(VDF-TrFE) powder is 5-20:100, and stir magnetically to obtain a mixed solution. 3) Take the mixed solution obtained in step 2) and drop it onto the graphene / copper high index crystal plane substrate, and spin coat it at a speed of 500-1000 rpm for 3-10 s, and then spin coat it at a speed of 1500-3000 rpm for 30-60 s. 4) Finally, the spin-coated substrate is subjected to vacuum annealing to obtain an organic-inorganic ferroelectric polymer composite film. The annealing temperature is 150-180 ℃, and the annealing time is 2-4 h.

2. The method for preparing an organic-inorganic ferroelectric polymer composite film according to claim 1, characterized in that, The graphene / copper high-index crystal plane substrate is a graphene / copper (122) substrate, a graphene / copper (431) substrate, or a graphene / copper (311) substrate.

3. The method for preparing an organic-inorganic ferroelectric polymer composite film according to claim 1, characterized in that, The purity of the tetrahydrofuran is not lower than that of analytical grade.

4. An organic-inorganic ferroelectric polymer composite film prepared by the method according to any one of claims 1-3.

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