Optically active polydiacetylene film, method for preparing the same, and use thereof

Abstract

The application provides an optically active polydiacetylene film and a preparation method and application thereof. The preparation method comprises the following steps: forming a nanowire array on a substrate, which comprises a first nanowire layer and a second nanowire layer arranged in sequence in a direction away from the substrate, and the nanowires contained in the first and second nanowire layers have a non-zero torsion angle; depositing an achiral diacetylene monomer on the nanowire array, removing the nanowire array to obtain a diacetylene monomer crystal layer; and irradiating the diacetylene monomer crystal layer with ultraviolet light to make it polymerize to form a helical polydiacetylene chain, thereby obtaining the optically active polydiacetylene film. The method provided by the application forms stereoregulated diacetylene crystals through the heteroepitaxy effect of the twisted stacked nanowire array, and only needs to be irradiated with ultraviolet light to initiate the asymmetric polymerization of diacetylene, thereby solving the problems that the crystal structure is difficult to be regulated as required and an exogenous chirality needs to be introduced in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of chiral functional polymer technology, specifically relating to an optically active polydiacetylene thin film, its preparation method, and its application. Background Technology

[0002] Twisted epitaxy-mediated asymmetric polymerization and chiral regulation have long been hot topics in the fields of materials science and nanotechnology. Related research involves multiple disciplines, such as materials science, nanotechnology, organic chemistry, and optics. Its continuous development has also promoted scientific and technological progress and innovation in the fields of two-dimensional material synthesis and chiral functional materials.

[0003] Currently, existing methods for achieving asymmetric polymerization typically rely on exogenous chiral input, which leads to high costs and stringent requirements for the purity of the introduced chiral source. Furthermore, existing epitaxial growth techniques for optically active thin films usually employ a single substrate, resulting in difficulties in controlling the crystal structure grown on demand. Summary of the Invention

[0004] To solve all or part of the above-mentioned technical problems, the present invention provides the following technical solutions:

[0005] A first aspect of the present invention provides a method for preparing an optically active polyacetylene thin film, comprising:

[0006] A nanowire array is formed on a substrate, the nanowire array comprising a first nanowire layer and a second nanowire layer arranged sequentially in a direction away from the substrate, wherein the orientation of the first nanowire contained in the first nanowire layer and the orientation of the second nanowire contained in the second nanowire layer are different, thereby forming a non-zero twist angle between the first nanowire and the second nanowire.

[0007] Chiral diacetylene monomers are deposited on the nanowire array, and the nanowire array induces the chiral diacetylene monomers to form a stereoregular stacking structure, thereby obtaining a diacetylene monomer crystal layer.

[0008] The diacetylene monomer crystal layer is irradiated with ultraviolet light to cause it to polymerize and form helical polyacetylene chains, thereby obtaining an optically active polyacetylene film.

[0009] The method provided by this invention forms stereoregular diacetylene (DA) crystals through heteroepitaxial growth of twisted and stacked nanowire arrays, solving the problem of difficulty in controlling the crystal structure as needed in the prior art. Subsequently, asymmetric polymerization of diacetylene can be initiated by ultraviolet light irradiation to form helical polydiacetylene chains without the need for external chiral input, solving the problems of high cost and stringent requirements for the purity of chiral sources (such as chiral catalysts, chiral reactants, etc.) in the prior art.

[0010] In some embodiments, the angle between the first nanowire and a designated side of the substrate is defined as a first angle (i.e., the "orientation" of the first nanowire is the first angle), and the angle between the second nanowire and the designated side is defined as a second angle (i.e., the "orientation" of the second nanowire is the second angle). The absolute value of the difference between the first angle and the second angle is the magnitude of the torsion angle, such that the magnitude of the torsion angle is 15° to 45°. Therefore, the diacetylene monomer crystal structure contained in the diacetylene monomer crystal layer deposited on the nanowire array is "V"-shaped, with a crystal opening angle of 15° to 45°.

[0011] In some embodiments, the non-chiral diacetylene monomer is deposited on the nanowire array using vapor deposition.

[0012] In some embodiments, the deposition temperature of the vapor deposition method is -5℃ to 35℃, preferably 30℃ to 35℃.

[0013] In some embodiments, the deposition pressure of the vapor deposition method is 1.0 × 10⁻⁶. -1 Pa ~ 1.0 × 10 -3 Pa.

[0014] In some embodiments, the deposition rate of the vapor deposition method is 0.01 nm / s to 0.05 nm / s.

[0015] In some embodiments, the diacetylene monomer crystal layer is irradiated with conventional ultraviolet light or circularly polarized ultraviolet light. The "conventional ultraviolet light" referred to in this invention means unpolarized ultraviolet light.

[0016] In some embodiments, the conventional ultraviolet light irradiation conditions include: a light power density of 0.5 mW / cm². 2 ~10mW / cm 2 The irradiation time is 1 min to 25 min.

[0017] In some embodiments, the circularly polarized ultraviolet light is either left-handed or right-handed circularly polarized ultraviolet light.

[0018] In some embodiments, the conditions for the circularly polarized ultraviolet light irradiation include: using left-handed or right-handed circularly polarized ultraviolet light as the light source, with a light power density of 0.5 mW / cm². 2 ~10 mW / cm 2 The irradiation time is 1 min to 25 min.

[0019] In some embodiments, the direction of the second nanowire's rotational stacking relative to the first nanowire is adjusted to control the direction of crystal stacking in the diacetylene monomer crystal layer to be clockwise or counterclockwise; the chirality of the helical polyacetylene chain is controlled by adjusting the direction of crystal stacking in the diacetylene monomer crystal layer to match or oppose the chirality of the circularly polarized ultraviolet light, thereby generating a synergistic chiral amplification effect or an antagonistic chiral attenuation effect.

[0020] In some embodiments, the preparation method further includes: removing the nanowire array before subjecting it to ultraviolet light irradiation. The method for removing the nanowire array can be, for example, etching, such as nitric acid etching.

[0021] In some embodiments, the non-chiral diacetylene monomer includes one or more of 10,12-pentacarbazide diacetic acid, azophenyl 10,12-pentacarbazide diacetic acid, benzaldehyde-10,12-pentacarbazide diacetic acid, and 10,12-tricarbazide diacetic acid.

[0022] In some embodiments, the first nanowire and the second nanowire may be metal nanowires or metal oxide nanowires. The metal element involved may be a metal commonly known for preparing nanowires. For example, the metal may include one or more of silver, gold, tellurium, copper, and zinc, and the metal oxide may include one or more of oxides of silver, gold, tellurium, copper, and zinc, but is not limited thereto.

[0023] In some embodiments, the methods for forming the first nanowire layer and the second nanowire layer include, but are not limited to, any one of the LB (Langmuir-Blodgett) film method and the dip-coating method.

[0024] In some embodiments, the substrate material includes one or more combinations of glass, quartz, and transparent polymers. The transparent polymer may, for example, include one or more combinations of polyvinyl alcohol (PVA), polyethylene terephthalate (PET), and polydimethylsiloxane (PDMS).

[0025] In some embodiments, the preparation method further includes: subjecting the substrate to plasma treatment to reduce the water contact angle on the substrate surface and enhance the adhesion between the nanowires and the substrate.

[0026] A second aspect of the present invention provides an optically active polyacetylene film, which is prepared by the method for preparing an optically active polyacetylene film as described in any of the technical solutions.

[0027] A third aspect of the present invention provides the application of the optically active polyacetylene thin film described in any of the technical solutions in 3D optical displays, chiral sensing, or information encryption. For example, its application in the fabrication of 3D optical display products or chiral sensors.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] (1) The preparation method provided by the present invention forms a “V” oriented structure of diacetylene (DA) crystal through heteroepitaxial effect of twisted stacked nanowire arrays, which solves the problem that the crystal structure is difficult to control as needed in the prior art; the asymmetric polymerization of diacetylene can be initiated by ultraviolet light (UV) irradiation without the need for external chiral input, which solves the problems of high cost and strict requirements for the purity of chiral source in the prior art when introducing chiral source (such as chiral catalyst, chiral reactant, etc.);

[0030] (2) In some preferred embodiments of the present invention, selective adjustment of chiral deviation is achieved by synergistic irradiation with circularly polarized ultraviolet light (CPUL): when the chirality of CPUL matches the direction of crystal stacking in the diacetylene monomer crystal layer, a synergistic chiral amplification effect is triggered; when the chirality of CPUL is opposite to the direction of crystal stacking in the diacetylene monomer crystal layer, the helical preference of the helical PDA chain is changed; compared with a single chiral control method, the flexibility and controllability of the chiral response of polydiacetylene film are significantly improved. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart illustrating the preparation process of one embodiment of the present invention;

[0033] Figure 2a This is a structural diagram of a diacetylene crystal epitaxial thin film in one embodiment of the present invention;

[0034] Figure 2b This is a schematic diagram of the structure of the optically active polyacetylene film finally obtained in one embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram illustrating the formation principle of an optically active polyacetylene film in one embodiment of the present invention.

[0036] Figure 4aThis is a schematic diagram showing that in Example 1, the direction of the rotational stacking of the second nanowire relative to the first nanowire is clockwise;

[0037] Figure 4b This is a schematic diagram showing that in Example 1, the direction of the second nanowire's rotational stacking relative to the first nanowire is counterclockwise.

[0038] Figure 5 This is a transmission electron microscope image of the self-made silver nanowires used in Example 1a;

[0039] Figure 6 The polar coordinate diagram shows the absorbance of the monolayer oriented silver nanowires prepared in Example 1a at different angles at 385 nm.

[0040] Figure 7 The polarization absorption spectrum of the polydiacetylene film obtained by using the monolayer oriented silver nanowires prepared in Example 1a as an epitaxial template and the polar coordinate diagram of the absorbance at different angles at 660 nm.

[0041] Figure 8 Transmission electron microscope image of the twisted stacked silver nanowire array prepared in Example 1a;

[0042] Figure 9 The circular dichroism chromatogram of the twisted stacked silver nanowire array prepared in Example 1a;

[0043] Figure 10 The circular dichroism chromatogram of the optically active polyacetylene film obtained by using the twisted stacked silver nanowire array prepared in Example 1a as an epitaxial template.

[0044] Figure 11a The circular dichroism chromatogram of the optically active polyacetylene thin film prepared in Example 1a under phase transition (blue phase to red phase upon heating) with a twist angle of 45° and a clockwise (CW) twisted stack.

[0045] Figure 11b The circular dichroism chromatogram of the optically active polyacetylene film prepared in Example 1a under phase transition (blue phase to red phase upon heating) with a twist angle of 45° and counterclockwise (CCW) twisted stacking.

[0046] Figure 12a This is a confocal microscope image of the optically active polyacetylene film prepared in Example 1a;

[0047] Figure 12b This is a confocal microscope image of the optically active polyacetylene film prepared in Example 1b;

[0048] Figure 12c This is a confocal microscope image of the optically active polyacetylene film prepared in Example 1c;

[0049] Figure 13a The X-ray diffraction patterns of the optically active polyacetylene films prepared in Examples 1a, 1b, and 1c are shown.

[0050] Figure 13b The polymerization rates of the optically active polyacetylene films prepared in Examples 1a, 1b, and 1c are shown.

[0051] Figure 13c The circular dichroism chromatograms of the optically active polyacetylene films prepared in Examples 1a, 1b, and 1c are shown.

[0052] Figure 14a The diagram shows a schematic (left) of the “V”-shaped stacked diacetylene monomer crystal structure obtained by epitaxy on a silver nanowire array with a twist angle of 15° in Example 1e, and a circular dichroism chromatogram (right) of the obtained optically active polyacetylene film.

[0053] Figure 14b The diagram shows a schematic (left) of the “V”-shaped stacked diacetylene monomer crystal structure obtained by epitaxy on a silver nanowire array with a twist angle of 30° in Example 1f, and a circular dichroism chromatogram (right) of the obtained optically active polyacetylene film.

[0054] Figure 14c The diagram shows a schematic (left) of the “V”-shaped stacked diacetylene monomer crystal structure obtained by epitaxy on a silver nanowire array with a twist angle of 45° in Example 1a, and a circular dichroism chromatogram (right) of the obtained optically active polyacetylene film.

[0055] Figure 15a This is a schematic diagram illustrating the multi-scale synergistic chiral amplification effect achieved by photopolymerization of epitaxially grown CW-type diathyne monomer crystal layers using L-CPUL in Example 2a.

[0056] Figure 15b The asymmetric absorption factor (g) of the three optically active polyacetylene films obtained in Examples 1a, 2a, and Comparative Example 1a is given. abs ) Spectrum;

[0057] Figure 15c The optically active polyacetylene films of Examples 1a, 1d, 1e (corresponding to "CW+UV" in the figure) and Examples 2a-2c (corresponding to "CW+L-CPUL" in the figure) at 690 nm are g abs Bar chart;

[0058] Figure 15d The optically active polyacetylene films of Examples 2a and 2d-2g under different polymerization light intensities are g at 690 nm. abs Bar chart;

[0059] Figure 16a Asymmetric absorption factors (g abs ) spectra of three optically active polydiacetylene films obtained in Example 1a, Example 3a, and Comparative Example 1b;

[0060] Figure 16b Variation of the chiral signal intensity at 690 nm with polymerization time of a polydiacetylene film formed by photopolymerization of a CW-type diacetylene crystal with a twist angle of 15° grown epitaxially using R-CPUL in Example 3c;

[0061] Figure 16c g at 690 nm of optically active polydiacetylene films obtained in Example 1a, 1d, 1e (corresponding to "CW+UV" in the figure) and Example 3a-3c (corresponding to "CW+R-CPUL" in the figure); abs Bar chart

[0062] Figure 16d g at 690 nm of optically active polydiacetylene films in Example 3a and Example 3d-3g under different polymerization light intensities; abs Bar chart;

[0063] Figure 17a Shows the physical diagram of the PDA film obtained by irradiation with circularly polarized ultraviolet light of different polarization states, and its g abs Bar chart at 690 nm and ultraviolet-visible absorption broken line chart at 660 nm;

[0064] Figure 17b Shows the realization of PDA patterning by mask lithography technology, and compares the g abs Spectrum and absorption spectrum before (i) and after (ii) bending of the flexible patterned PDA film;

[0065] Figure 17c Shows that through mask lithography technology, a patterned PDA film with independent absorption and g abs values realizes the ASCII encoding-decryption and decoding of the Chinese character "Ning".

[0066] Figure 17d Shows that through mask lithography technology, a patterned PDA film with independent absorption and g abs value channels uses Morse code encoding and decoding to achieve multi-information encryption. Detailed implementation manners

[0067] The invention will be more fully understood through the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the specific functional details disclosed herein should not be construed as limiting, but rather as the basis for the claims and as intended to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0068] In addition, unless otherwise specified, all raw materials used in the following embodiments can be purchased from the market or other sources, and all production and testing equipment used are known in the art, as are the testing methods used.

[0069] This invention provides a method for preparing an optically active polyacetylene thin film. Figure 1 This is a flowchart illustrating the preparation process for one embodiment. Figure 2a This is a structural diagram of a diacetylene crystal epitaxial thin film according to one embodiment. Figure 2b This is a schematic diagram of the structure of the optically active polyacetylene film finally obtained in one embodiment; Figure 3 This is a schematic diagram illustrating the formation principle of an optically active polydiacetylene thin film according to one embodiment. Please refer to the reference. Figure 1 , Figure 2a , Figure 2b , Figure 3 The preparation method includes:

[0070] S1: Provides substrate 100;

[0071] S2: A twisted and stacked array of silver nanowires 200 is formed on the surface of substrate 100, which serves as a heteroepitaxial template to provide a spatial confinement template for the subsequent growth of "V"-shaped diacetylene crystals.

[0072] The silver nanowire array 200 includes a first silver nanowire layer 210 and a second silver nanowire layer 220 sequentially disposed along a direction away from the substrate 100. The orientation of the first silver nanowires contained in the first silver nanowire layer 210 is at a first angle (referring to the angle between the first silver nanowire and a specified side direction of the substrate 100). The orientation of the second silver nanowires contained in the second silver nanowire layer 220 is at a second angle (referring to the angle between the second silver nanowire and the same specified side direction). The first angle and the second angle are different, so there is a non-zero twist angle between the first silver nanowire and the second silver nanowire (the magnitude of the twist angle is the absolute value of the difference between the first angle and the second angle, i.e., θ in Figure 4).

[0073] S3: A non-chiral diacetylene monomer is deposited on the surface of the silver nanowire array 200. The epitaxial interaction and van der Waals forces between the silver nanowires and the diacetylene monomer are used to induce the diacetylene monomer to form a stereoregular "V" shaped stacking structure, thus obtaining the diacetylene monomer crystal layer 300.

[0074] S4: Remove silver nanowire array 200;

[0075] S5: The diacetylene monomer crystal layer 300 is irradiated with conventional ultraviolet light (UV) or circularly polarized ultraviolet light (CPUL) to form an optically active polyacetylene film 400 with a controllable helical direction.

[0076] In one embodiment, step S2 specifically includes S21 and S22:

[0077] S21: A first silver nanowire layer 210 is formed on the surface of the substrate 100, and the orientation of the first silver nanowire layer 210 is at a first angle;

[0078] S22: A second silver nanowire layer 220 is formed on the surface of the first silver nanowire layer 210, such that the orientation of the second silver nanowire layer 220 is a second angle.

[0079] The specific methods for forming the first silver nanowire layer 210 and the second silver nanowire layer 220 can be the LB film method, dip-coating method, etc., and the present invention does not impose any particular limitation on this method; the specific method depends on the circumstances. The LB film method, dip-coating method, etc., can all form nanowire layers composed of multiple nanowires with the same orientation. For example, multiple nanowires may be parallel to a specified edge of the substrate, or may all be at the same angle to a specified edge of the substrate.

[0080] For example, the preparation method of the first silver nanowire layer 210 may include: taking an AgNWs solution (concentration can be 0.5~5 mg / ml) and dripping it onto the center of the surface of the ethylene glycol container at an injection rate of 0~30 ml / h; immediately after injection, dripping a hexadecyltrimethylammonium chloride aqueous solution (CTAC, concentration can be 50~150 mM) into the center of the container to induce the AgNWs to align at the liquid edge; after the solvent evaporates, transferring the AgNWs oriented onto the surface of the substrate 100 to form a continuous first silver nanowire layer 210. The preparation method of the second silver nanowire layer 220 may, for example, use an AgNWs solution of the same concentration as the first silver nanowire layer 210, and adjust the substrate fixing angle of the LB film device to make the orientation of the second silver nanowire layer at a second angle to form the second silver nanowire layer 220.

[0081] By making the first angle different from the second angle, a non-zero twist angle is formed between the first silver nanowire and the second silver nanowire. The specific size of the first angle and the second angle can be flexibly adjusted according to the actual situation.

[0082] The rotational stacking direction of the silver nanowire layers determines the crystal stacking direction in the diacetylene monomer crystal layer and affects the helical direction of the polyacetylene. For example, in a typical embodiment, the first angle is set to 0°, meaning the silver nanowires of the first silver nanowire layer are parallel to a specified edge of the substrate. Then, the second silver nanowire layer is rotated and stacked on top of the first silver nanowire layer in a clockwise or counterclockwise direction, with a twist angle of 15° to 45°. When the second silver nanowire layer is rotated and stacked clockwise on top of the first silver nanowire layer, the resulting diacetylene monomer crystal layer has a clockwise crystal stacking direction, denoted as a CW-type diacetylene monomer crystal layer. When the second silver nanowire layer is rotated and stacked counterclockwise on top of the first silver nanowire layer, the resulting diacetylene monomer crystal layer has a counterclockwise crystal stacking direction, denoted as a CCW-type diacetylene monomer crystal layer.

[0083] Furthermore, the diameter and length of the silver nanowires used can be flexibly selected as needed, and there are no particular limitations on them. Silver nanowires can be prepared by any known method, such as the hydrothermal method. Preferably, the silver nanowires are hydroxylated to enhance their interaction with the DA monomer.

[0084] In one embodiment, step S3 specifically includes:

[0085] Chiral diacetylene monomers were deposited on the surface of a twisted stacked silver nanowire array 200 using chemical vapor deposition. Deposition conditions included: deposition temperature -5℃ to 35℃, and deposition pressure 1.0 × 10⁻⁶. -1 Pa ~ 1.0 × 10 -3 Pa, deposition rate 0.01 nm / s ~ 0.05 nm / s, deposition thickness 5 μm ~ 30 μm, to obtain 300 diacetylene monomer crystal layers.

[0086] The relative orientation (twist angle) and deposition temperature of the twisted stacked silver nanowire array are independent experimental parameters for customizing the DA monomer crystal structure. The orientation of the dominant helical chains in the PDA film is strictly controlled by the relative orientation of the silver nanowires. When the twist angle is 15°~45° and the growth temperature is -5℃~35℃, the opening angle (15°~45°) and crystal orientation degree of the "V"-shaped diacetylene monomer crystal can be customized. When the twist angle is 15°~45° and the deposition temperature is 30~35℃, the crystal orientation of the "V"-shaped diacetylene crystal is obvious, which is the preferred condition. When the angle difference is 45° and the deposition temperature is 35℃, the crystal orientation of the "V"-shaped diacetylene crystal is greatly enhanced, which is the optimal condition. When the temperature is too low, the deposition rate of diacetylene monomer is too slow, and the crystal orientation weakens.

[0087] In one embodiment, step S4 specifically includes: removing the twisted stacked silver nanowire array 200 by nitric acid etching.

[0088] For example, the conditions for nitric acid etching may include immersion in a 14 mol / L to 15 mol / L nitric acid solution for 3 to 5 minutes to ensure complete removal of silver nanowires without damaging the diacetylene crystal structure.

[0089] In one embodiment, step S5 includes: irradiating the diacetylene monomer crystal layer 300 with conventional ultraviolet light (unpolarized ultraviolet light) to achieve enantioselective polymerization of the chiral diacetylene monomer. The irradiation conditions may include: using an ultraviolet mercury lamp with a light power density of 0.5 mW / cm² to 10 mW / cm². 2 Irradiation time is 1 min to 25 min to form an optically active poly(diacetylene) film 400. Thus, without any chiral input, the diacetylene monomer forms a preliminary helical poly(diacetylene) (PDA) chain through solid-state topological photopolymerization, resulting in a helical poly(diacetylene) material with a controllable helical direction, namely the optically active poly(diacetylene) film 400.

[0090] In the above-described embodiment of conventional ultraviolet irradiation, the CW-type diethyne monomer crystal layer ultimately forms a left-handed polydiethyne chain, and the CCW-type diethyne monomer crystal layer ultimately forms a right-handed polydiethyne chain.

[0091] In another embodiment, step S5 includes: irradiating the "V"-shaped diacetylene monomer crystal layer 300 with circularly polarized ultraviolet light (CPUL) to adjust its helical direction. Specifically, this may include: using left-handed circularly polarized ultraviolet light (L-CPUL) or right-handed circularly polarized ultraviolet light (R-CPUL) to irradiate the diacetylene monomer crystal layer 300, with a light power density of 0.5 W / cm². 2 ~10mW / cm 2 Irradiation time is 1 min to 25 min to form an optically active polydiacetylene film 400.

[0092] When the chirality of CPUL matches the crystal stacking direction in the diacetylene monomer crystal layer, it means that L-CPUL acts on a CW-type diacetylene monomer crystal layer, or R-CPUL acts on a CCW-type diacetylene monomer crystal layer. In this case, a synergistic chiral amplification effect is triggered, and the intensity of the CD characteristic peak is significantly increased. When the chirality of CPUL is opposite to the crystal stacking direction in the diacetylene monomer crystal layer, it means that R-CPUL acts on a CW-type diacetylene monomer crystal layer, or L-CPUL acts on a CCW-type diacetylene monomer crystal layer. In this case, an antagonistic chiral attenuation effect is produced, changing the helical preference of the initial helical PDA chain, and the intensity of the CD characteristic peak decreases or flips.

[0093] Single-factor regulation in helical polymer chirality control refers to relying solely on epitaxy on a single substrate or a single chiral bias (e.g., a single chiral catalyst or a single circularly polarized light). Multi-factor synergistic regulation refers to combining different regulatory methods (e.g., the synergistic effect of twisted epitaxial structured templates and circularly polarized ultraviolet light). Single-factor regulation is, to some extent, detrimental to the precise matching of monomer assembly and crystal orientation. For example, in the preparation of helical polymers and the optimization of chiral properties, especially in the dynamic adjustment of the conversion of achiral monomers to chiral polymers, asynchronous regulation often occurs. Furthermore, existing single-factor regulation techniques cannot independently modulate the crystal orientation-inducing effect of twisted epitaxial templates and the chiral amplification / reversal effect of circularly polarized ultraviolet light, making it difficult to clarify their respective contributions and interactions in asymmetric polymerization. In the preferred embodiment of this invention, a dual mechanism of "twisted stacked silver nanowire array template induction" combined with "CPUL synergistic / antagonistic" is used to achieve precise control of the helical direction. Specifically, nanowire arrays fix the initial stacking orientation of DA crystals through heteroepitaxial growth, providing a "topological template" for the PDA helical structure; CPUL further modulates the symmetry breaking during the polymerization process through a chiral light field, achieving precise control of the helical direction. By controlling the twist angle, the twist stacking direction, and the CPUL helix direction, 4 to 6 different chiral response modes can be constructed, and all control parameters exhibit good repeatability. This provides customizable functional materials for fields such as chiral sensing and 3D optical displays, showing significant application potential.

[0094] like Figure 2b As shown, the final structure of the optically active polyacetylene film includes a substrate 100 and an optically active polyacetylene film 400 located on the surface of the substrate 100.

[0095] The technical solution of the present invention will be further described below with reference to specific embodiments:

[0096] Example 1a

[0097] This embodiment provides an optically active polydiacetylene thin film and its preparation method, specifically including the following steps:

[0098] S1: Prepare the substrate. The substrate material is PDMS.

[0099] S2: A twisted stacked silver nanowire array is formed on the substrate surface using the LB film method as a heteroepitaxial template. This twisted stacked silver nanowire array is directly attached to the substrate surface, and its twisted structure provides a spatially confined template for the subsequent growth of "V"-shaped DA crystals. S2 specifically includes S21 and S22:

[0100] S21: Take 3 ml of AgNWs solution (silver nanowires with a diameter of 40 nm and a length of 3 µm, AgNWs solution concentration of 1 mg / ml) and drip it into the center of the ethylene glycol-filled container (diameter of 15 cm) at an injection rate of 20 ml / h. After injection, immediately drip 3 mL of hexadecyltrimethylammonium chloride aqueous solution (100 mM) into the center of the container to induce AgNWs to align at the liquid edge. After the solvent evaporates, transfer AgNWs to the substrate surface in a directional manner, making AgNWs parallel to the specified edge direction of the substrate (i.e., the first angle is 0°), to form a continuous first silver nanowire layer.

[0101] S22: The second silver nanowire layer is prepared using an AgNWs solution of the same concentration as in step S21. The preparation method is basically the same, except that the substrate fixing angle of the LB film device is adjusted so that the second silver nanowire layer is rotated 45° clockwise along the specified side direction (since the first angle is 0°, the twist angle between the silver nanowires contained in the first and second silver nanowire layers is 45°). Figure 4a This is a schematic diagram showing that the second nanowire is rotated and stacked in a clockwise direction relative to the first nanowire.

[0102] S3: 10,12-pentacarbazinoic acid was deposited on the surface of a twisted stacked silver nanowire array via chemical vapor deposition; the specific deposition conditions were: deposition temperature 35℃, deposition pressure 1.0×10⁻⁶. -1 Pa, deposition rate 0.01 nm / s, deposition thickness 5 μm; by utilizing the epitaxial interaction and van der Waals forces between silver nanowires and 10,12-tetrapentacardiyne, a stereoregular "V" shaped stacking structure of 10,12-tetrapentacardiyne was induced, and a CW-type diacetylene monomer crystal layer was obtained.

[0103] S4: Soak the structure obtained in step S3 in 14 mol / L nitric acid solution for 3 min to completely remove the silver nanowire array.

[0104] S5: The diacetylene monomer crystal layer was subjected to conventional ultraviolet irradiation, specifically including: using an ultraviolet mercury lamp as the light source, with a light power density of 8.5 mW / cm². 2 The irradiation time is 10 min to achieve enantioselective polymerization of diacetylene monomers, forming levorotatory polyacetylene chains, thereby obtaining optically active polyacetylene films.

[0105] In addition, Example 1a also prepared an optically active polydiacetylene film based on a right-handed polydiacetylene chain. The only difference from the above method is that in step S22, the second silver nanowire layer is rotated counterclockwise by 45° along the specified side direction (since the first angle is 0°, the twist angle between the silver nanowires contained in the first silver nanowire layer and the second silver nanowire layer is 45°). Figure 4bThis is a schematic diagram showing the second nanowire being stacked in a counter-clockwise direction relative to the first nanowire. Thus, under the same deposition conditions as described above, step S3 yields a CCW-type diacetylene monomer crystal layer. After conventional ultraviolet irradiation as described above, a right-handed polyacetylene chain is formed, thereby obtaining an optically active polyacetylene film.

[0106] Figure 5 This is a transmission electron microscope image of the self-made silver nanowires used in Example 1a. Figure 6 This is a polar coordinate diagram showing the absorbance of the monolayer oriented silver nanowires prepared in Example 1a at different angles at 385 nm. Figure 7 The polarization absorption spectrum of the poly(diacetylene) film obtained by using the monolayer oriented silver nanowires prepared in Example 1a as an epitaxial template, and its polar coordinate plots at different angles at 660 nm, are shown. Combined with... Figure 5 , Figure 6 as well as Figure 7 It can be seen that the diacetylene monomer and polyacetylene crystal achieved precise orientation along the oriented silver nanowires.

[0107] Figure 8 This is a transmission electron microscope (TEM) image of the twisted stacked silver nanowire array prepared in Example 1a. Figure 9 The image shows a circular dichroism chromatogram of the twisted stacked silver nanowire array prepared in Example 1a. Figure 10 The image shows a circular dichroism chromatogram of an optically active polyacetylene film obtained using the twisted stacked silver nanowire array prepared in Example 1a as an epitaxial template. Figure 11a The image shows a circular dichroism chromatogram of the optically active polyacetylene thin film prepared in Example 1a, which is twisted and stacked in a clockwise direction (CW) with a twist angle of 45°, under the phase transition (blue phase to red phase upon heating). Figure 11b The image shows a circular dichroism chromatogram of the optically active polyacetylene thin film prepared in Example 1a, with a counterclockwise (CCW) twisted stack and a twist angle of 45°, during the phase transition (blue phase to red phase upon heating). Combined with... Figure 8 , Figure 9 , Figure 10 , Figure 11a , Figure 11b It is known that the diacetylene monomer achieved selective spatial matching on the surface of the twisted and stacked silver nanowire bilayer structure through a heteroepitaxial growth strategy, ultimately yielding an optically active polyacetylene film.

[0108] Examples 1b-1c

[0109] Examples 1b and 1c are basically the same as Example 1a, except that the deposition temperature of step S3 is changed according to Table 1. The rest of the examples are the same as Example 1a, and will not be described again here.

[0110] Table 1

[0111] Group Example 1a Example 1b Example 1c Example 1d Deposition temperature 35℃ 15℃ -5℃ 30℃

[0112] Figure 12a , Figure 12b , Figure 12c The images shown in sequence are confocal microscope images of the optically active polyacetylene films prepared in Examples 1a, 1b, and 1c. Figure 13a The X-ray diffraction patterns of the optically active polyacetylene films prepared in Examples 1a (corresponding to "i" in the figure), 1b (corresponding to "ii" in the figure), and 1c (corresponding to "iii" in the figure) are shown. Figure 13b The polymerization rates of the optically active polyacetylene films prepared in Example 1a (corresponding to "i" in the figure), Example 1b (corresponding to "ii" in the figure), and Example 1c (corresponding to "iii" in the figure) are shown. Figure 13c Circular dichroism chromatograms of the optically active polyacetylene films prepared in Examples 1a (corresponding to "i" in the figure), 1b (corresponding to "ii" in the figure), and 1c (corresponding to "iii" in the figure) are shown. The effect of Example 1d is essentially equivalent to that of Example 1a. (Refer to reference...) Figures 12a-12c , Figures 13a-13c It is known that, with the torsion angle unchanged, different deposition temperatures correspond to different crystallization states. The preferred deposition temperature is 30℃~35℃. Within this preferred temperature range, a uniformly twisted and stacked polydiacetylene crystal structure can be successfully achieved through a heteroepitaxial growth strategy. This breaks the in-plane and out-of-plane symmetry, thereby generating a strong chiral optical response.

[0113] Example 1e-Example 1f

[0114] Examples 1e and 1f are basically the same as Example 1a, except that in step S22, the substrate fixing angle of the LB film device is adjusted to adjust the angle between the second silver nanowire layer and the specified edge direction, thereby controlling the size of the twist angle (as shown in Table 2). CW-type and CCW-type diacetylene monomer crystal layers are then obtained by controlling the direction of the twisted stacking, thus obtaining optically active polyacetylene films with different chiralities. The rest of the examples are the same as Example 1a and will not be repeated here.

[0115] Table 2

[0116] Group Example 1a Example 1e Example 1f Twist angle size 45° 15° 30°

[0117] Figure 14a The diagram shows a schematic (left) of the “V”-shaped stacked diacetylene monomer crystal structure obtained by epitaxy on a silver nanowire array with a twist angle of 15° in Example 1e, and a circular dichroism chromatogram (right) of the obtained optically active polyacetylene film. Figure 14bA schematic diagram (left) of the “V”-shaped stacked diacetylene monomer crystal structure obtained by epitaxy on a silver nanowire array with a twist angle of 30° in Example 1f is shown, as well as a circular dichroism chromatogram (right) of the obtained optically active polyacetylene film. Figure 14c A schematic diagram (left) of the “V”-shaped stacked diacetylene monomer crystal structure obtained by epitaxy on a silver nanowire array with a twist angle of 45° in Example 1a is shown, along with a circular dichroism chromatogram (right) of the obtained optically active polyacetylene film. (Refer to reference...) Figures 14a-14c It can be seen that, under the condition that other factors remain unchanged, the optical activity of polydiacetylene crystal films increases with the increase of the twist angle (15°~45°), and its optical activity is the strongest when the twist angle reaches 45°.

[0118] Example 2a

[0119] This embodiment provides an optically active polydiacetylene thin film and its preparation method, specifically including the following steps:

[0120] S1: Prepare the substrate. The substrate material is PDMS.

[0121] S2: A twisted stacked silver nanowire array is formed on the substrate surface using the LB film method as a heteroepitaxial template. This twisted stacked silver nanowire array is directly attached to the substrate surface, and its twisted structure provides a spatially confined template for the subsequent growth of "V"-shaped DA crystals. S2 specifically includes S21 and S22:

[0122] S21: Take 3 ml of AgNWs solution (silver nanowires with a diameter of 40 nm and a length of 3 µm, AgNWs solution concentration of 1 mg / ml) and drip it into the center of the ethylene glycol-filled container (diameter of 15 cm) at an injection rate of 20 ml / h. After injection, immediately drip 3 mL of hexadecyltrimethylammonium chloride aqueous solution (100 mM) into the center of the container to induce AgNWs to align at the liquid edge. After the solvent evaporates, transfer AgNWs to the substrate surface in a directional manner, making AgNWs parallel to the specified edge direction of the substrate (i.e., the first angle is 0°), to form a continuous first silver nanowire layer.

[0123] S22: The second silver nanowire layer is prepared using an AgNWs solution of the same concentration as in step S21. The preparation method is basically the same, except that the substrate fixing angle of the LB film device is adjusted so that the angle between the second silver nanowire layer and the direction along the specified side is rotated clockwise by 45° (since the first angle is 0°, the twist angle between the silver nanowires contained in the first silver nanowire layer and the second silver nanowire layer is 45°).

[0124] S3: 10,12-pentacarbazinoic acid was deposited on the surface of a twisted stacked silver nanowire array via chemical vapor deposition; the specific deposition conditions were: deposition temperature 35℃, deposition pressure 1.0×10⁻⁶. -1 Pa, deposition rate 0.01 nm / s, deposition thickness 5 μm; by utilizing the epitaxial interaction and van der Waals forces between silver nanowires and 10,12-tetrapentacardiyne, a stereoregular "V" shaped stacking structure of 10,12-tetrapentacardiyne was induced, and a CW-type diacetylene monomer crystal layer was obtained.

[0125] S4: Soak the structure obtained in step S3 in 14 mol / L nitric acid solution for 3 min to completely remove the silver nanowire array.

[0126] S5: Irradiate the above-mentioned CW-type diacetylene monomer crystal layer with left-handed circularly polarized ultraviolet light, specifically including: using left-handed circularly polarized ultraviolet light as the light source, with a light power density of 8.5 mW / cm². 2 An optically active polyacetylene film was obtained by irradiation for 10 minutes.

[0127] Examples 2b-2c

[0128] The only difference between Examples 2b-2c and Example 2a is that the size of the torsion angle is changed according to Table 3. The rest is the same as Example 2a and will not be described again here.

[0129] Table 3

[0130] Group Example 2a Example 2b Example 2c Torsion angle size 45° 30° 15°

[0131] Example 2d-2g

[0132] The only difference between Examples 2d-2g and Example 2a is that the optical power density of the left-handed circularly polarized ultraviolet light in step S5 is changed according to Table 4. The rest are the same as in Example 2a and will not be repeated here.

[0133] Table 4

[0134] Group Example 2a Example 2d Example 2e Example 2f Example 2g <![CDATA[Optical power density of left-handed circularly polarized ultraviolet light (mW / cm 2 )]]> 8.5 1.7 3.4 5.1 6.8

[0135] Example 3a

[0136] This embodiment provides an optically active polydiacetylene thin film and its preparation method, specifically including the following steps:

[0137] S1: Prepare the substrate. The substrate material is PDMS.

[0138] S2: A twisted stacked silver nanowire array is formed on the substrate surface using the LB film method as a heteroepitaxial template. This twisted stacked silver nanowire array is directly attached to the substrate surface, and its twisted structure provides a spatially confined template for the subsequent growth of "V"-shaped DA crystals. S2 specifically includes S21 and S22:

[0139] S21: Take 3 ml of AgNWs solution (silver nanowires with a diameter of 40 nm and a length of 3 µm, AgNWs solution concentration of 1 mg / ml) and drip it into the center of the ethylene glycol-filled container (diameter of 15 cm) at an injection rate of 20 ml / h. After injection, immediately drip 3 mL of hexadecyltrimethylammonium chloride aqueous solution (100 mM) into the center of the container to induce AgNWs to align at the liquid edge. After the solvent evaporates, transfer AgNWs to the substrate surface in a directional manner, making AgNWs parallel to the specified edge direction of the substrate (i.e., the first angle is 0°), to form a continuous first silver nanowire layer.

[0140] S22: The second silver nanowire layer is prepared using an AgNWs solution of the same concentration as in step S21. The preparation method is basically the same, except that the substrate fixing angle of the LB film device is adjusted so that the angle between the second silver nanowire layer and the direction along the specified side is rotated counterclockwise by 45° (since the first angle is 0°, the twist angle between the silver nanowires contained in the first silver nanowire layer and the second silver nanowire layer is 45°).

[0141] S3: 10,12-pentacarbazinoic acid was deposited on the surface of a twisted stacked silver nanowire array via chemical vapor deposition; the specific deposition conditions were: deposition temperature 35℃, deposition pressure 1.0×10⁻⁶. -1 Pa, deposition rate 0.01 nm / s, deposition thickness 5 μm; by utilizing the epitaxial interaction and van der Waals forces between silver nanowires and 10,12-tetrapentacardiyne, a stereoregular "V" shaped stacking structure of 10,12-tetrapentacardiyne was induced, and a CW-type diacetylene monomer crystal layer was obtained.

[0142] S4: Soak the structure obtained in step S3 in 14 mol / L nitric acid solution for 3 min to completely remove the silver nanowire array.

[0143] S5: Irradiate the above-mentioned CW-type diacetylene monomer crystal layer with right-handed circularly polarized ultraviolet light, specifically including: using right-handed circularly polarized ultraviolet light as the light source, with a light power density of 8.5 mW / cm². 2 An optically active polyacetylene film was obtained by irradiation for 10 minutes.

[0144] Examples 3b-3c

[0145] The only difference between Examples 3b-3c and Example 3a is that the size of the torsion angle is changed according to Table 5. The rest is the same as Example 3a and will not be described again here.

[0146] Table 5

[0147] Group Example 3a Example 3b Example 3c Torsion angle size 45° 30° 15°

[0148] Example 3d-3g

[0149] The only difference between Examples 3d-3g and Example 3a is that the optical power density of the right-hand circularly polarized ultraviolet light in step S5 is changed according to Table 6. The rest are the same as in Example 3a and will not be repeated here.

[0150] Table 6

[0151] Group Example 3a Example 3d Example 3e Example 3f Example 3g <![CDATA[Optical power density (mW / cm 2 )]]> 8.5 1.7 3.4 5.1 6.8

[0152] Comparative Example 1a

[0153] S1: Prepare the substrate. The substrate material is PDMS.

[0154] S2: 10,12-tetradecanoic acid was deposited on the above substrate by chemical vapor deposition; the specific deposition conditions were: deposition temperature 35℃, deposition pressure 1.0×10⁻⁶. -1 Pa, deposition rate 0.01 nm / s, deposition thickness 5 μm, forming a randomly oriented diacetylene monomer crystal layer.

[0155] S5: Irradiate the randomly oriented diacetylene monomer crystal layer with left-handed circularly polarized ultraviolet light, specifically including: using left-handed circularly polarized ultraviolet light as the light source, with a power density of 8.5 mW / cm². 2 The irradiation time is 10 minutes.

[0156] Comparative Example 1b

[0157] S1: Prepare the substrate. The substrate material is PDMS.

[0158] S2: 10,12-tetradecanoic acid was deposited on the above substrate by chemical vapor deposition; the specific deposition conditions were: deposition temperature 35℃, deposition pressure 1.0×10⁻⁶. -1 Pa, deposition rate 0.01 nm / s, deposition thickness 5 μm, forming a randomly oriented diacetylene monomer crystal layer.

[0159] S5: Irradiate the randomly oriented diacetylene monomer crystal layer with right-handed circularly polarized ultraviolet light, specifically including: using right-handed circularly polarized ultraviolet light as the light source, with a power density of 8.5 mW / cm². 2 The irradiation time is 10 minutes.

[0160] Figure 15a This is a schematic diagram of using L-CPUL to perform photopolymerization on an epitaxially grown CW-type diathyne monomer crystal layer to achieve chiral synergistic amplification in Example 2a. Figure 15b The asymmetric absorption factor (g) of the three optically active polyacetylene films obtained in Example 1a (corresponding to "i" in the figure), Example 2a (corresponding to "iii" in the figure), and Comparative Example 1a (corresponding to "ii" in the figure) is... abs ) Spectrum. Figure 15c The optically active polyacetylene films of Examples 1a, 1d, 1e (corresponding to "CW+UV" in the figure) and Examples 2a-2c (corresponding to "CW+L-CPUL" in the figure) at 690 nm are g abs Bar chart. Figure 15d The optically active polyacetylene films under different polymerization light intensities in Examples 2a and 2d-2g are g at 690 nm. abs Bar chart. (Refer to reference) Figures 15a-15d It is evident that far-field circularly polarized ultraviolet light plays a crucial role in the chiral regulation of poly(diacetylene) molecular chain growth. When the chirality of the circularly polarized ultraviolet light matches the chirality of the poly(diacetylene), a synergistic chiral amplification effect is triggered. This "chiral matching" refers to irradiating a CW-type diacetylene monomer crystal layer with left-handed circularly polarized ultraviolet light, or irradiating a CCW-type diacetylene monomer crystal layer with right-handed circularly polarized ultraviolet light. The synergistic effect between the intrinsic geometric chirality of the V-shaped diacetylene monomer crystal and the far-field circularly polarized ultraviolet light-induced polymerization jointly achieves the chiral amplification effect in the asymmetric photopolymerization reaction.

[0161] Figure 16a The circular dichroism chromatograms are for the three optically active polyacetylene films obtained in Example 1d (corresponding to "i" in the figure), Example 3a (corresponding to "iii" in the figure), and Comparative Example 1b (corresponding to "ii" in the figure). Figure 16b The graph shows the change in chiral signal intensity at 690 nm as a function of polymerization time for a polydiacetylene film formed by photopolymerization of CW-type acetylene monomer crystals with a twist angle of 15° grown epitaxially using R-CPUL in Example 3c. Figure 16c The optically active polyacetylene films obtained in Examples 1a, 1d, 1e (corresponding to "CW+UV" in the figure) and Examples 3a-3c (corresponding to "CW+R-CPUL" in the figure) at 690 nm are g. abs Bar chart. Figure 16d The optically active polyacetylene films under different polymerization light intensities in Examples 3a and 3d-3g are g at 690 nm. abs Bar chart. (Refer to reference) Figures 16a-16d It can be seen that when the intensity of right-handed circularly polarized ultraviolet light (R-CPUL) is fixed at 8.5 mW / cm 2When the torsional angle of the diacetylene monomer crystal is relatively large (such as 30° - 45°), the overall enantioselectivity of the PDA film is mainly dominated by the intrinsic chirality of the monomer crystal; while when the torsional angle is small (within the range of 0° - 30°), the chiral regulation effect of circularly polarized ultraviolet light (CPUL) dominates (as Figure 16c shown). This phenomenon stems from the fact that the intrinsic chirality formed by the diacetylene monomer crystal at a large torsional angle is stronger, and the regulation effect of the externally applied reverse chiral CPUL is not sufficient to reverse its inherent chirality. Similarly, when the torsional angle of the diacetylene monomer crystal is fixed at 15°, the irradiation of high-intensity CPUL (such as an intensity of 3.4 mW / cm 2 ~8.5 mW / cm 2 ) can completely cover the intrinsic chirality regulation effect of the monomer crystal, thereby dominating the overall optical activity of the PDA film (as Figure 16d shown). The overall enantioselectivity of the polydiacetylene (PDA) film is a direct manifestation of the dynamic interaction between the far-field chirality of circularly polarized ultraviolet light (CPUL) and the spatial geometric intrinsic chirality of the V-shaped diacetylene (DA) monomer crystal.

[0162] Figure 17a shows the physical pictures of the PDA films obtained by irradiating with circularly polarized ultraviolet light of different polarization states, as well as their g abs histogram at 690 nm and the UV-visible absorption broken line graph at 660 nm.

[0163] The present invention also uses a mask lithography technique to achieve patterning of the PDA film, and to achieve ASCII encoding-decoding and Morse code encoding and decoding. Figure 17b shows the "flower" PDA patterning on the flexible PDMS film achieved by the mask lithography technique and compares the g abs spectra and absorption spectra of the flexible patterned PDA film before (i) and after (ii) bending. Figure 17c shows that through the mask lithography technique, the patterned PDA film with independent absorption and g abs values realizes the ASCII encoding-decoding and decoding of the Chinese character "Ning". Figure 17d shows that through the mask lithography technique, the patterned PDA film with channels of independent absorption and g abs values realizes multi-information encryption using Morse code encoding and decoding.

[0164] Combined with reference Figures 17a-17d it can be seen that by regulating the polarization state of circularly polarized ultraviolet light (CPUL), fine regulation of the chirality of the PDA film can be achieved under the same irradiation time while keeping the absorption intensity basically constant (as Figure 17a(As shown). This characteristic stems from the fact that the polarization states corresponding to different latitudes on the Poincaré sphere can be effectively inscribed onto the PDA thin film, allowing for stepless adjustment of optical activity in the positive and negative ranges, and decoupling of chiral modulation and absorption characteristics. Similarly, patterned PDA structures can be fabricated on flexible PDMS thin films using photomask lithography, and their absorption intensity is related to g. abs The value remains stable even after high bending (e.g.) Figure 17b As shown in the figure, this is due to the excellent mechanical deformability of the PDMS substrate and the structural stability of the PDA thin film. Furthermore, based on the absorption intensity (dominant channel) and g... abs The dual-parameter independent control of the value (latent channel) allows the patterned PDA film to achieve ASCII encoding decryption and Chinese character decoding (e.g., Figure 17c (as shown); and by g abs The values ​​correspond to Morse code symbols, which can be used to construct a second layer of encrypted information channels to achieve multi-mode information encryption (such as...). Figure 17d (As shown). The multidimensional information encryption and high-density storage capabilities of polydiacetylene (PDA) thin films are a direct manifestation of the synergistic effect of polarization state control of polarized light, mask lithography patterning technology, and the chiral optical properties of PDA. Its orthogonal and controllable parameter system provides core support for high-performance optical anti-counterfeiting and information storage.

[0165] The above description illustrates that the preparation method provided by this invention can control the structure of the "V"-shaped DA crystal by adjusting the relative orientation (twist angle) of the nanowire array and the deposition temperature, thereby controlling the helical direction of the PDA film. In some preferred embodiments, chirality can be further amplified or antagonistically adjusted through CPUL. By controlling the nanowire array orientation and CPUL parameters, the chirality of the optically active poly(diacetylene) film can be programmable, facilitating functional customization in 3D optical displays, chiral sensing, and information encryption. This provides a feasible solution for the precise design of chiral functional materials and has significant application prospects. The preparation method of this invention enables full-process controllability from "crystal structure customization - chiral input-free polymerization - precise chiral adjustment." The prepared optically active PDA film has unique application value in chiral sensing (such as enantiomer recognition), 3D optical displays (tunable helical polarization), and information encryption (chiral response switching). It solves the problems of existing technologies where chiral control depends on external chiral input and the crystal structure and chiral response are difficult to optimize synergistically, demonstrating significant technological breakthrough and industrialization potential.

[0166] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0167] All aspects, embodiments, features, and examples of this invention should be considered illustrative and used to explain and illustrate the invention, but not to limit the invention. The scope of the invention is defined only by the claims.

[0168] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the described embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims.

Claims

1. A method for preparing an optically active polyacetylene thin film, characterized in that, include: A nanowire array is formed on a substrate, comprising a first nanowire layer and a second nanowire layer arranged sequentially in a direction away from the substrate. The orientations of the first nanowires in the first nanowire layer and the second nanowires in the second nanowire layer are different, resulting in a non-zero twist angle between the first nanowires and the second nanowires. Chiral diacetylene monomers are deposited on the nanowire array, and the nanowire array induces the chiral diacetylene monomers to form a stereoregular stacking structure, thereby obtaining a diacetylene monomer crystal layer. The diacetylene monomer crystal layer is irradiated with ultraviolet light to cause it to polymerize and form helical polyacetylene chains, thereby obtaining an optically active polyacetylene film.

2. The preparation method according to claim 1, characterized in that: The angle between the first nanowire and a specified side of the substrate is defined as a first angle, and the angle between the second nanowire and the specified side is defined as a second angle. The absolute value of the difference between the first angle and the second angle is the magnitude of the torsion angle, such that the magnitude of the torsion angle is 15°~45°.

3. The preparation method according to claim 1, characterized in that: The non-chiral diacetylene monomer is deposited on the nanowire array using vapor deposition; and the deposition temperature of the vapor deposition method is -5℃ to 35℃, preferably 30℃ to 35℃.

4. The preparation method according to any one of claims 1-3, characterized in that: The diacetylene monomer crystal layer was irradiated with conventional ultraviolet light or circularly polarized ultraviolet light.

5. The preparation method according to claim 4, characterized in that: The conventional ultraviolet light irradiation conditions include: a light power density of 0.5 mW / cm². 2 ~10 mW / cm 2 The irradiation time is 1 min to 25 min.

6. The preparation method according to claim 4, characterized in that: The irradiation conditions for the circularly polarized ultraviolet light include: using either left-handed or right-handed circularly polarized ultraviolet light as the light source, with a light power density of 0.5 mW / cm². 2 ~10 mW / cm 2 The irradiation time is 1 min to 25 min.

7. The preparation method according to claim 6, characterized in that: By adjusting the direction of the second nanowire's rotational stacking relative to the first nanowire, the direction of crystal stacking in the diacetylene monomer crystal layer can be adjusted to be clockwise or counterclockwise; and by adjusting the direction of crystal stacking in the diacetylene monomer crystal layer to match or oppose the chirality of the circularly polarized ultraviolet light, a synergistic chiral amplification effect or an antagonistic chiral attenuation effect is generated, thereby controlling the chirality of the helical polyacetylene chain.

8. The preparation method according to claim 1, characterized in that, Also includes: Remove the nanowire array and then perform the ultraviolet light irradiation; And / or, the non-chiral diacetylene monomer includes one or more of 10,12-pentacarbondiyne acid, azophenyl 10,12-pentacarbondiyne acid, benzaldehyde-10,12-pentacarbondiyne acid, and 10,12-tricarbodiyne acid. And / or, the first nanowire and the second nanowire contain materials of metal and / or metal oxide, wherein the metal includes at least one of silver, gold, tellurium, copper and zinc, and the metal oxide includes at least one of oxides of nickel, copper and zinc; And / or, the method for forming the first nanowire layer and the second nanowire layer includes any one of the LB film method and the dip-coating method.

9. An optically active polydiacetylene thin film, characterized in that, It is prepared by any one of claims 1 to 8.

10. The application of the optically active polyacetylene thin film according to claim 9 in 3D optical display, chiral sensing or information encryption.

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