Preparation method of flexible stretchable assembly film and flexible stretchable chiral film

Abstract

The invention relates to the technical field of preparation of chiral films, in particular to a flexible stretchable assembled film and a preparation method of a flexible stretchable chiral film. The method comprises the following steps: dropwise adding inorganic nanoparticles serving as functional elements to the surface of a double-sided tape by utilizing the stretchable-relaxation characteristic of a linear polymer and the birefringence effect generated after stretching, and promoting directional arrangement of the inorganic nanoparticles on the double-sided tape through stretching of the double-sided tape, so as to form a double-sided adhesive tape; and then, the flexible stretchable chiral thin film with a high g-factor is constructed in a twisting and stacking manner. According to the invention, different inorganic nanoparticles are added, so that chiral signals of different wave bands can be regulated and controlled. Besides, the strength of a chiral signal is controlled by regulating and controlling the stretch ratio, and in the flexible stretchable chiral film based on the Ag nanoparticles, the chiral signal of the flexible stretchable chiral film is stronger along with the increase of the stretch ratio.

Description

Technical Field

[0001] The present invention relates to the technical field of chiral film preparation, and in particular to a method for preparing a flexible stretchable assembly film and a flexible stretchable chiral film. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Chirality, the mirror-image asymmetry of matter, is a fundamental geometric property that permeates everything from amino acids to spiral galaxies. Chiral materials respond differently to left-handed and right-handed circularly polarized light. Leveraging this property, chiral materials have applications in 3D displays, information storage and processing, biological probes, information encryption, and photocatalysis.

[0004] Currently, conventional chiral thin films are mostly made of inorganic materials (such as chiral metal nanostructures and chiral photonic crystals) or rigid polymers (such as chiral liquid crystal polymers). These materials generally have high mechanical strength and stability, but poor flexibility. With the development of flexible electronics, biosensors, and wearable devices, flexible chiral thin films have gradually become a research hotspot.

[0005] However, in the visible light region, most polymer-based chiral materials exhibit only weak chiral responses, with optical asymmetry factors (g-factors) typically less than 0.1. This phenomenon is primarily due to the mismatch between the molecular scale and the visible light photon scale. Furthermore, the optical activity intensity of polymer-based chiral materials cannot be flexibly adjusted. These shortcomings limit the application of flexible chiral films in chiral optics. Therefore, there is an urgent need to develop polymer-based chiral materials with high optical activity, good mechanical deformability, and controllable chiral optical properties. Summary of the Invention

[0006] In order to overcome the above problems, the present invention provides a method for preparing a flexible stretchable assembly film and a flexible stretchable chiral film.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] A first aspect of the present invention provides a method for preparing a flexible stretchable assembly membrane, comprising the following steps:

[0009] (1) adding oleic acid to an inorganic nanomaterial solution to obtain an assembly solution;

[0010] (2) The assembly liquid is dropped onto one side of a transparent elastic double-sided tape. After drying, the tape is stretched to a defined length in both directions to obtain a flexible stretchable assembly film.

[0011] In one or more embodiments, the inorganic nanomaterial is selected from inorganic nanowires, inorganic nanoparticles, and inorganic nanorods;

[0012] Preferably, the inorganic nanowires are selected from cadmium sulfide nanowires, CeMoO x Nanowires and NiMoO4 nanowires, preferably cadmium sulfide nanowires; further preferably, the aspect ratio of the inorganic nanowires is greater than 1000;

[0013] Preferably, the inorganic nanoparticles are selected from one or more of gold nanoparticles and silver nanoparticles; further preferably, the particle size of the gold nanoparticles and silver nanoparticles is 5 to 30 nm;

[0014] Preferably, the inorganic nanorods are one or more of gold nanorods and silver nanorods; further preferably, the diameter of the gold nanorods and silver nanorods is 20-50 nm, and the long diameter is 50-200 nm.

[0015] In one or more embodiments, the solvent in the inorganic nanomaterial solution is n-hexane. N-hexane has good dispersibility for the inorganic nanomaterial and is highly volatile, making it easy to dry the assembly solution.

[0016] In one or more embodiments, the concentration of the inorganic nanomaterial solution is 4.5 to 6 g / L, preferably 5 g / L. At this concentration, a flexible, stretchable chiral film with a strong chiral signal can be obtained.

[0017] In one or more embodiments, the volume ratio of the inorganic nanomaterial solution to oleic acid is 1:(1-50‰), preferably 1:10‰. The addition of oleic acid acts like a lubricant, ensuring continuity in the deformation of the nanoparticles during stretching, rather than rigid disconnection.

[0018] In one or more embodiments, based on 500 to 1000 mm 2 The transparent elastic double-sided tape, the amount of assembly liquid is 450 ~ 600μL; preferably based on 800mm 2 The transparent elastic double-sided tape was prepared with a volume of 500 μL of assembly solution. Under this ratio, a flexible and stretchable chiral film with a strong chiral signal can be obtained.

[0019] In one or more embodiments, the drying method is natural drying.

[0020] In one or more embodiments, the defined direction is the length direction of the transparent elastic double-sided tape.

[0021] In one or more embodiments, the stretch ratio is 2 to 10, preferably 7, where the stretch ratio is the ratio of the length after stretching to the original length. At this stretch ratio, a flexible and stretchable chiral film with a strong chiral signal can be obtained.

[0022] The second aspect of the present invention provides a flexible stretchable assembly film prepared by the above preparation method.

[0023] A third aspect of the present invention provides a method for preparing a flexible stretchable chiral film, comprising the following steps:

[0024] stretching a blank transparent elastic double-sided tape in both directions to a defined length to obtain a blank assembly film;

[0025] The blank assembly film is placed on top of the flexible and stretchable assembly film described in the second aspect to obtain a flexible and stretchable chiral film.

[0026] In one or more embodiments, the defined direction is the length direction of the transparent elastic double-sided tape.

[0027] In one or more embodiments, the stretching ratio is 2 to 10, preferably 7, where the stretching ratio is the ratio of the length after stretching to the original length.

[0028] In one or more embodiments, the distance between the bottom surface of the blank assembly film and the top surface of the flexible stretchable assembly film is 0 to 6 cm. The strength of the chiral signal will not be affected by directly stacking the blank assembly film and the flexible stretchable assembly film or by placing a limited distance between them.

[0029] In one or more embodiments, the clockwise angle between the centerline of the blank assembly film and the centerline of the flexible stretchable assembly film is 0 to 90 degrees, preferably 45 degrees; the counterclockwise angle is 0 to 90 degrees, preferably 45 degrees. Clockwise represents a left-handed structure (LH); counterclockwise represents a right-handed structure (RH).

[0030] The flexible and stretchable chiral film of the present invention can selectively absorb left-handed / right-handed circularly polarized light, has a high asymmetry factor (g-factor), and exhibits ultrahigh optical activity.

[0031] The beneficial effects of the present invention are:

[0032] (1) During the stretching process, the molecular chains of linear polymers, such as transparent elastic double-sided tape, can be oriented along the stretching direction, forming an ordered structure with a certain degree of orientation, thereby endowing the polymer with birefringence. Therefore, utilizing the stretch-relaxation property of linear polymers and the birefringence effect produced after stretching, inorganic nanoparticles are added as functional elements to the surface of the double-sided tape. The stretching of the double-sided tape promotes the directional arrangement of the inorganic nanoparticles on the double-sided tape, and then a flexible stretchable chiral film with a high asymmetry factor (g-factor) is constructed by twisting and stacking. The flexible stretchable chiral film obtained by the present invention exhibits high optical activity, with an asymmetry factor (g-factor) as high as 0.2.

[0033] (2) The present invention can regulate chiral signals in different wavelength bands by adding different inorganic nanoparticles. Furthermore, the present invention controls the intensity of the chiral signal by adjusting the stretch ratio. In a flexible, stretchable chiral film based on Ag nanoparticles, the chiral signal of the flexible, stretchable chiral film increases with increasing stretch ratio.

[0034] (3) The present invention provides a series of flexible and stretchable chiral films with excellent performance, promoting their wide application in optoelectronic devices, biosensors, electromagnetic shielding and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 The preparation process of the blank assembly film and the flexible stretchable assembly film, wherein a is the preparation process of the blank assembly film, and b is the preparation process of the flexible stretchable assembly film;

[0037] Figure 2 These are optical microscope and polarizing microscope photos of the flexible stretchable assembly membrane in Example 1; wherein a is an optical microscope photo and b is a polarizing microscope photo;

[0038] Figure 3 This is a polarizing microscope photograph of the flexible stretchable assembly film in Example 1 when it is rotated in a clockwise direction;

[0039] Figure 4 : The first flexible stretchable chiral film based on Ag nanoparticles and the second flexible stretchable chiral film based on Ag nanoparticles are shown in Figure 1; wherein, a is the second flexible stretchable chiral film based on Ag nanoparticles (RH), and b is the first flexible stretchable chiral film based on Ag nanoparticles (LH);

[0040] Figure 5 Circular dichroism spectra and asymmetry factor (g-factor) diagrams of the first flexible stretchable chiral film based on Ag nanoparticles and the second flexible stretchable chiral film based on Ag nanoparticles; wherein a is the circular dichroism spectrum and b is the asymmetry factor (g-factor) diagram;

[0041] Figure 6 The asymmetry factor (g-factor) of the flexible stretchable chiral film based on Ag nanoparticles at different stretching ratios, where a is the asymmetry factor (g-factor) diagram at different stretching ratios, and b is the peak statistical diagram of the asymmetry factor (g-factor);

[0042] Figure 7 TEM image of cadmium sulfide nanowires;

[0043] Figure 8 Circular dichroism spectra and asymmetry factor (g-factor) diagrams of the first flexible stretchable chiral film based on cadmium sulfide nanowires and the second flexible stretchable chiral film based on cadmium sulfide nanowires; wherein a is the circular dichroism spectrum and b is the asymmetry factor (g-factor) diagram;

[0044] Figure 9 Circular dichroism spectra and asymmetry factor (g-factor) diagrams of the first flexible stretchable chiral film based on Au nanoparticles and the second flexible stretchable chiral film based on Au nanoparticles; wherein a is the circular dichroism spectrum and b is the asymmetry factor (g-factor) diagram. DETAILED DESCRIPTION

[0045] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0046] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0047] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0048] The transparent elastic double-sided adhesive tape in the present invention is a commercially available transparent double-sided adhesive tape, and brands include Deli, Chenguang, and Situ. In the following embodiments, the commercially available Deli transparent elastic double-sided adhesive tape is used, and the width is 20 mm.

[0049] Example 1

[0050] Preparation of flexible and stretchable chiral films based on Ag nanoparticles:

[0051] (1) Synthesis of Ag nanoparticles:

[0052] First, 1.78 g of AgNO3 and 30 mL of oleylamine were mixed in a 100 mL three-necked flask; then, the three-necked flask was placed on a 60°C heating platform to completely dissolve the AgNO3; the solution was rapidly heated to 180°C at a heating rate of 10°C / min under stirring and maintained at this temperature for 1 hour; finally, the reaction system was cooled to room temperature, toluene was added to dilute the product and washed with acetone; during the washing process, the particle size distribution of the nanoparticles was optimized through a size selection process to obtain Ag nanoparticles with a particle size of 8 to 12 nm. The Ag nanoparticles were dispersed in n-hexane to obtain an Ag nanoparticle solution (5 g / L) for later use.

[0053] (2) Oleic acid was added to the Ag nanoparticle solution (5 g / L) with a volume ratio of 1:10‰ to obtain an assembly solution; the assembly solution (500 μL) was deposited on the single-side surface of a transparent elastic double-sided tape (width × length × thickness of 20 mm × 40 mm × 1 mm), and after naturally drying in a fume hood, the transparent elastic double-sided tape was stretched in both directions along the length direction with a stretching ratio of 7, where the stretching ratio is the ratio of the stretched length to the original length; a flexible stretchable assembly film was obtained.

[0054] A blank transparent elastic double-sided tape (width × length × thickness: 20 mm × 40 mm × 1 mm) was stretched in both directions along the length direction at a stretch ratio of 7, where the stretch ratio is the ratio of the stretched length to the original length, to obtain a blank assembly film;

[0055] A blank assembly film was stacked on top of the flexible stretchable assembly film to obtain a flexible stretchable chiral film. When the clockwise angle between the centerline of the blank assembly film and the centerline of the flexible stretchable assembly film was 45°, a first flexible stretchable chiral film (LH) based on Ag nanoparticles was obtained. When the counterclockwise angle between the centerline of the blank assembly film and the centerline of the flexible stretchable assembly film was 45°, a second flexible stretchable chiral film (RH) based on Ag nanoparticles was obtained.

[0056] Figure 1 The preparation process of blank assembly membrane and flexible stretchable assembly membrane, from Figure 1It can be seen that the transparent elastic double-sided tape has good tensile properties and still has good tensile properties after loading the Ag nanoparticles, and the macroscopic wrinkles generated by the nanoparticles during the stretching process show one-dimensional stripes.

[0057] Figure 2 To obtain the optical microscope and polarizing microscope photos of the flexible stretchable assembled film in this embodiment, Figure 2 It can be seen that the Ag nanoparticles present a one-dimensional striped structure during the stretching process, proving that the nanoparticles can achieve structural reconstruction under the action of the stretching double-sided tape.

[0058] Figure 3 Polarized microscope photos of the flexible stretchable assembly membrane obtained in this embodiment when rotating in a clockwise direction are obtained. Figure 3 It can be seen that the Ag nanoparticles under the polarizing microscope show light and dark changes that depend on the rotation angle, proving that the stretched Ag nanoparticles have excellent polarization properties.

[0059] Figure 4 These are actual pictures of the first flexible and stretchable chiral film based on Ag nanoparticles and the second flexible and stretchable chiral film based on Ag nanoparticles.

[0060] Figure 5 Circular dichroism spectra and asymmetry factor (g-factor) diagram of the first flexible stretchable chiral film (LH) based on Ag nanoparticles and the second flexible stretchable chiral film (RH) based on Ag nanoparticles, Figure 5 It can be seen that the chirality of Ag nanoparticles can be controlled by stretching and rotation, with an asymmetry factor (g-factor) greater than 0.1, and good chiral optical properties.

[0061] The performance of chiral materials is evaluated by the asymmetry factor (g-factor), which is defined as: g-factor = 2(A L -A R ) / (A L +A R ); where A L and A R Represents the absorbance of left-circularly polarized light and right-circularly polarized light, respectively. Larger values ​​indicate stronger performance.

[0062] Figure 6 is the asymmetry factor (g-factor) of the flexible stretchable chiral film based on Ag nanoparticles at different stretching ratios, Figure 6 It can be seen that the intensity of the chiral signal can be controlled by adjusting the stretching ratio. As the stretching ratio increases, the chiral signal of the flexible stretchable chiral film becomes stronger.

[0063] Example 2

[0064] Preparation of flexible and stretchable chiral films based on cadmium sulfide nanowires:

[0065] (1) Preparation of cadmium sulfide nanowires:

[0066] 1.28 g of cadmium oxide (CdO) and 10 mL of oleic acid (OA) were added to a round-bottom flask and heated under N2 protection to prepare a cadmium oleate precursor (Cd-OA). The mixed solution was first heated to 160 ° C and maintained for 1 h until the solution turned transparent brown. Subsequently, the solution was cooled to 100 ° C and vacuum degassed for about 40 min until no bubbles were generated, and then cooled to 50 ° C. 2 mL of pre-prepared TOP-S solution (0.8 g of sulfur powder (S ) was dissolved in 10 mL of tri-n-octylphosphine (TOP) solution); the Cd-OA / TOP-S mixed solution was heated to 130° C., and the solution became turbid when cadmium sulfide nanowires were formed; the solution was maintained at this temperature for 1 hour, then quenched with an equal volume of ethyl acetate and centrifuged at 7000 rpm for 3 minutes; the precipitate was dissolved with n-hexane, precipitated with an equal volume of ethyl acetate and centrifuged; finally, the cadmium sulfide nanowires were dispersed in n-hexane to obtain a cadmium sulfide nanowire solution (5 g / L) for later use.

[0067] Figure 7 TEM image of cadmium sulfide nanowires. Figure 7 The assembled cadmium sulfide nanowires have a one-dimensional structure that is tens or even hundreds of microns long.

[0068] (2) Oleic acid was added to a cadmium sulfide nanowire solution (5 g / L) with a volume ratio of 1:10‰ to obtain an assembly solution; the assembly solution (500 μL) was deposited on a single surface of a transparent elastic double-sided tape (width × length × thickness of 20 mm × 40 mm × 1 mm), and after naturally drying in a fume hood, the transparent elastic double-sided tape was stretched in both directions along its length with a stretching ratio of 7, where the stretching ratio is the ratio of the length after stretching to the original length; and a flexible stretchable assembly film was obtained.

[0069] A blank transparent elastic double-sided tape (width × length × thickness: 20 mm × 40 mm × 1 mm) was stretched in both directions along the length direction at a stretch ratio of 7, where the stretch ratio is the ratio of the stretched length to the original length, to obtain a blank assembly film;

[0070] A blank assembly film was stacked on top of a flexible stretchable assembly film to obtain a flexible stretchable chiral film. When the clockwise angle between the centerline of the blank assembly film and the centerline of the flexible stretchable assembly film was 45°, a first flexible stretchable chiral film (LH) based on CdS nanowires was obtained. When the counterclockwise angle between the centerline of the blank assembly film and the centerline of the flexible stretchable assembly film was 45°, a second flexible stretchable chiral film (RH) based on CdS nanowires was obtained.

[0071] Figure 8 Circular dichroism spectra and asymmetry factor (g-factor) diagram of the first flexible stretchable chiral film (LH) based on cadmium sulfide nanowires and the second flexible stretchable chiral film (RH) based on cadmium sulfide nanowires, from Figure 8 It can be seen that the chirality of cadmium sulfide nanowires can be controlled by stretching and rotating, with an asymmetry factor greater than 0.1, and good chiral optical properties.

[0072] Example 3

[0073] Au nanoparticle synthesis: 100 mg of HAuCl₄·3H₂O, 10 mL of oleylamine, and 10 mL of toluene were added to a 100 mL three-necked flask. A toluene solution containing 30 mg of tert-butylamine borane was then quickly added. After stirring for 1 hour, oleylamine-ligand-modified Au nanoparticles were obtained. Au nanoparticles were purified by ethanol precipitation, centrifuged and washed at 7000 rpm for 2 min, and finally the precipitate was redispersed in 5 mL of toluene to prepare a seed solution with a concentration of 5 g / L; subsequently, a seed growth experiment was carried out to increase the particle size of the Au nanoparticles; 2 mL of toluene and 2 mL of oleylamine were added to a 20 mL glass bottle, 250 μL of the above seed solution was injected, and the glass bottle was placed on a 90°C heating platform for reaction for 3 h to promote full growth of the seeds; after the reaction was completed, the product was cooled to room temperature, and the Au nanoparticles were precipitated with ethanol, centrifuged and washed at 7000 rpm for 2 min, and finally redispersed in n-hexane to prepare a Au nanoparticle solution with a concentration of 5 g / L for use; the particle size of the Au nanoparticles was approximately 8 to 12 nm.

[0074] (2) Oleic acid was added to the Au nanoparticle solution (5 g / L) with a volume ratio of 1:10‰ to obtain an assembly solution; the assembly solution (500 μL) was deposited on the single-side surface of a transparent elastic double-sided tape (width × length × thickness of 20 mm × 40 mm × 1 mm), and after naturally drying in a fume hood, the transparent elastic double-sided tape was stretched in both directions along the length direction with a stretching ratio of 7, where the stretching ratio is the ratio of the stretched length to the original length; a flexible stretchable assembly film was obtained.

[0075] A blank transparent elastic double-sided tape (width × length × thickness: 20 mm × 40 mm × 1 mm) was stretched in both directions along the length direction at a stretch ratio of 7, where the stretch ratio is the ratio of the stretched length to the original length, to obtain a blank assembly film;

[0076] A blank assembly film was stacked on top of the flexible stretchable assembly film to obtain a flexible stretchable chiral film. When the clockwise angle between the centerline of the blank assembly film and the centerline of the flexible stretchable assembly film was 45°, a first Au nanoparticle-based flexible stretchable chiral film (LH) was obtained. When the counterclockwise angle between the centerline of the blank assembly film and the centerline of the flexible stretchable assembly film was 45°, a second Au nanoparticle-based flexible stretchable chiral film (RH) was obtained.

[0077] Figure 9 Circular dichroism spectra and asymmetry factor (g-factor) diagram of the first flexible stretchable chiral film (LH) based on Au nanoparticles and the second flexible stretchable chiral film (RH) based on Au nanoparticles, Figure 9 It can be seen that the chirality of Au nanoparticles can be controlled by stretching and rotation, with an asymmetry factor of about 0.2, and good chiral optical properties.

[0078] By comparing the circular dichroism spectra of flexible stretchable chiral films with different inorganic nanoparticles in Examples 1 to 3, it can be seen that chiral signals in different bands can be controlled by adding different inorganic nanoparticles.

[0079] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing a flexible stretchable assembly membrane, characterized in that: The steps include: (1) adding oleic acid to an inorganic nanomaterial solution to obtain an assembly solution; (2) The assembly liquid is dropped onto one side of a transparent elastic double-sided tape. After drying, the tape is stretched to a defined length in both directions to obtain a flexible stretchable assembly film.

2. The preparation method according to claim 1, wherein The inorganic nanomaterial is selected from inorganic nanowires, inorganic nanoparticles and inorganic nanorods; Preferably, the inorganic nanowires are selected from cadmium sulfide nanowires, CeMoO x Nanowires and NiMoO4 nanowires, preferably cadmium sulfide nanowires; further preferably, the aspect ratio of the inorganic nanowires is greater than 1000; Preferably, the inorganic nanoparticles are selected from one or more of gold nanoparticles and silver nanoparticles; further preferably, the particle size of the gold nanoparticles and silver nanoparticles is 5 to 30 nm; Preferably, the inorganic nanorods are one or more of gold nanorods and silver nanorods; further preferably, the diameter of the gold nanorods and silver nanorods is 20-50 nm, and the long diameter is 50-200 nm.

3. The preparation method according to claim 1, wherein In the inorganic nanomaterial solution, the solvent is n-hexane; Alternatively, the concentration of the inorganic nanomaterial solution is 4.5 to 6 g / L, preferably 5 g / L.

4. The preparation method according to claim 1, wherein The volume ratio of the inorganic nanomaterial solution to oleic acid is 1:(1-50‰), preferably 1:10‰.

5. The preparation method according to claim 1, wherein Based on 500~1000mm 2 The transparent elastic double-sided tape, the amount of assembly liquid is 450 ~ 600μL; preferably based on 800mm 2 The amount of assembly solution is 500 μL.

6. The preparation method according to claim 1, wherein The defined direction is the length direction of the transparent elastic double-sided tape Alternatively, the stretching ratio is 2 to 10, preferably 7, where the stretching ratio is the ratio of the length after stretching to the original length.

7. A flexible stretchable assembled membrane prepared by the preparation method according to any one of claims 1 to 6.

8. A method for preparing a flexible stretchable chiral film, characterized in that: The steps include: stretching a blank transparent elastic double-sided tape in both directions to a defined length to obtain a blank assembly film; The blank assembled film is placed on top of the flexible and stretchable assembled film according to claim 7 to obtain a flexible and stretchable chiral film.

9. The preparation method according to claim 8, wherein The defined direction is the length direction of the transparent elastic double-sided tape; Alternatively, the stretching ratio is 2 to 10, preferably 7, where the stretching ratio is the ratio of the length after stretching to the original length.

10. The preparation method according to claim 8, characterized in that The distance between the lower surface of the blank assembly film and the upper surface of the flexible stretchable assembly film is 0 to 6 cm.

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