Stretchable pedot electrode flexible light modulating film and method of making same

Abstract

The application discloses a stretchable PEDOT electrode flexible dimming film and a preparation method thereof, and belongs to the technical field of dimming films. The dimming film is a symmetrical five-layer laminated structure, which is composed of a thermoplastic polyurethane elastic substrate, a modified PEDOT composite electrode layer and a PDLC dimming layer. The electrode layer is prepared by copolymerization of a side chain functionalized EDOT derivative and EDOT and then polyion complex doping. The modified PEDOT aqueous dispersion is prepared by using an aqueous phase oxidation polymerization method, and after film coating, the film is synchronously ultraviolet cured with liquid crystal premix. The acrylate groups at the end of the PEDOT side chain participate in the polymerization reaction of the dimming layer, and the covalent bonding of the electrode and the dimming layer is realized synchronously. The dimming film has good tensile toughness, interfacial bonding force and electro-optical regulation performance, and the tensile cycle stability is significantly improved. The dimming film can be adapted to curved surface fitting, flexible intelligent window and other scenes, has strong process compatibility, and has good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of dimming film technology, and in particular to a stretchable PEDOT electrode flexible dimming film and its preparation method. Background Technology

[0002] Polymer dispersed liquid crystal (PDLC) dimming films, as an electrically controlled light scattering device, achieve reversible switching between transparent and scattering states by regulating the orientation and alignment of liquid crystal droplets through an electric field. With its advantages of simple fabrication process, no need for polarizers and alignment layers, and fast response speed, it shows broad application prospects in fields such as smart windows, flexible displays, and wearable devices. With the rapid development of smart interactive wearable electronic products, the application scenarios of PDLC dimming films are expanding from traditional rigid building curtain walls and automotive windows to curved screens, wearable devices, and flexible display panels that require bending and deformation adaptability. However, the transparent conductive electrodes used in currently commercially available PDLC devices are mostly indium tin oxide (ITO) / polyethylene terephthalate (PET) systems. The inherent brittleness of ITO films makes them prone to microcracks or even fracture under repeated bending or stretching conditions, severely limiting the development of PDLC devices in the field of flexible wearable electronics. Furthermore, traditional PDLC dimming films also suffer from narrow operating temperature ranges, high driving voltages, and performance degradation under extreme environments, making it difficult to meet the application requirements of high-end transportation scenarios such as automotive sunroofs and high-speed rail windows. Therefore, developing stretchable PDLC dimming films that combine low driving voltage, wide temperature range stability, and excellent mechanical flexibility has become a critical technological bottleneck that urgently needs to be overcome in this field.

[0003] Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), as a conductive polymer, is considered one of the most promising alternatives to ITO due to its excellent solution processability, good biocompatibility, and high transmittance in the visible light region. However, the original PEDOT:PSS film is inherently brittle and rigid. Its conjugated backbone exhibits strong π-π stacking interactions, resulting in tight molecular packing and difficulty in relative slippage. Furthermore, the PSS polystyrene backbone itself, as the continuous phase, is highly rigid, making it prone to direct breakage of conductive domains under tensile deformation, leading to rapid degradation of conductivity. Therefore, it cannot be directly used in flexible and stretchable electronic devices. More critically, the extensive encapsulation of the conductive PEDOT component by the insulating PSS component in PEDOT:PSS affects its conductivity, and the strong hygroscopicity of the PSS chains results in poor long-term stability of PEDOT:PSS in aqueous environments, further limiting its reliability in complex service environments. In stretchable PDLC devices, the aforementioned problems are particularly prominent. The electrode layer not only needs to withstand repeated stretching deformation and maintain the integrity of the conductive path, but also needs to form a strong interfacial bond with the PDLC dimming layer to avoid device failure due to interfacial delamination during mechanical cycling. Research shows that electronic device failure often begins with interlayer debonding, caused by insufficient interfacial adhesion and mismatch in mechanical properties between functional layers. In existing technologies, the electrodes and dimming layers of flexible PDLC dimming films are typically only physically bonded, with weak interfacial bonding. During repeated stretching cycles, electrode detachment and interfacial delamination easily occur, becoming one of the main failure modes limiting the lifespan of stretchable PDLC devices. How to simultaneously improve the stretching deformation capability and interfacial bonding stability of the PEDOT:PSS electrode while maintaining good conductivity and transmittance, achieving a synergistic match between the electrode and the PDLC dimming layer at both mechanical and functional levels, is a pressing technical challenge in this field. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a stretchable PEDOT electrode flexible dimming film and its preparation method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a stretchable PEDOT electrode flexible dimming film, which, from bottom to top, comprises a first elastic substrate, a first conductive electrode layer, a PDLC dimming layer, a second conductive electrode layer, and a second elastic substrate.

[0006] Preferably, both the first elastic substrate and the second elastic substrate are thermoplastic polyurethane films that have undergone oxygen plasma surface activation treatment, with a thickness of 30-80 μm.

[0007] Preferably, both the first conductive electrode layer and the second conductive electrode layer are modified PEDOT composite electrode layers, which are prepared by aqueous phase oxidation copolymerization of EDOT monomer and side-chain functionalized EDOT derivative in a molar ratio of 80-95:5-20, followed by doping with a polyanionic dopant, with a thickness of 80-220 nm. Preferably, the PDLC dimming layer is formed by UV curing of a dye-liquid mixture, with a thickness of 15-25 μm; wherein the dye-liquid mixture comprises, by mass parts: 45-60 parts of nematic liquid crystal, 38-52 parts of polyurethane acrylate prepolymer, 1-3 parts of photoinitiator, 0.1-0.5 parts of polymer microsphere spacers, 0.2-1 parts of chiral agent, and 0.5-2 parts of dichroic dye.

[0008] Preferably, the side-chain functionalized EDOT derivative has the following chemical structural formula: .

[0009] Preferably, the polyanionic dopant is a composite system of sodium polystyrene sulfonate and sulfonated styrene-ethylene-butene-styrene block copolymer in a mass ratio of 5-8:2-5.

[0010] Preferably, the polymer microsphere spacers are selected from at least one of polystyrene microspheres, polymethyl methacrylate microspheres, and polyurethane microspheres, with an average particle size of 15-25 μm.

[0011] More preferably, the polymer microsphere spacers are selected from polymethyl methacrylate microspheres with an average particle size of 15-25 μm.

[0012] Preferably, the preparation method of the side-chain functionalized EDOT derivative is as follows: (1) Under nitrogen protection, isophorone diisocyanate was added to anhydrous tetrahydrofuran, stirring was started, the temperature was raised to 35±2℃, and polyethylene glycol monoacrylate was added dropwise. During the dropwise addition, the reaction temperature was maintained at no more than 38℃. After the dropwise addition was completed, the reaction was kept at the temperature for 4-6 hours. After cooling to room temperature, thiophene[3,4-B]-1,4-dioxin-2-methanol and catalyst were added. Under stirring, the temperature was raised to 50-60℃ and the reaction was carried out for 6-10 hours. After the reaction was completed, the solvent was removed by vacuum distillation to obtain the crude product. The chemical reaction equation is as follows: Using isophorone diisocyanate as a coupling agent, a stepwise reaction is achieved by leveraging the difference in reactivity between the two isocyanate groups due to the asymmetry of its molecular structure. The two -NCO groups of isophorone diisocyanate are attached to different sites on the cyclohexane ring. The secondary -NCO, directly bonded to the 3-position of the ring, is less affected by steric hindrance and exhibits a more favorable electronic effect for nucleophilic addition, exhibiting a reactivity approximately 1.3-2.5 times that of the primary -NCO linked via a methylene group at the 1-position. During the reaction, by controlling the temperature within a low-temperature range of 35±2℃, only the highly reactive secondary -NCO is activated, causing it to undergo a carbamate reaction with the terminal hydroxyl group of the added polyethylene glycol monoacrylate, while the less reactive primary -NCO... The reaction rate is extremely low at the temperature, and it basically does not participate in the reaction, thus quantitatively obtaining a polyether acrylate intermediate with a single active NCO group retained at one end. No additional group protection-deprotection process is required, and the bifunctional byproducts of grafting NCO at both ends of the polyether are effectively avoided, ensuring the uniformity of the structure of the subsequent product. After the first step reaction is completed, thieno[3,4-B]-1,4-dioxin-2-methanol and catalyst are added and the temperature is raised to 50-60℃ to activate the low-activity primary-NCO so that it reacts with the hydroxyl groups of thieno[3,4-B]-1,4-dioxin-2-methanol, and finally obtains a side-chain functionalized EDOT monomer with an EDOT polymerization core at one end and an acrylate active group at the other end. (2) The crude product was completely dissolved in anhydrous methanol, transferred to a dialysis bag, sealed at both ends, and placed in a dialysis cylinder containing anhydrous methanol. Dialysis was performed at room temperature in the dark for 24-36 hours. After dialysis, the solution in the bag was removed, methanol was removed by vacuum distillation, and dried to obtain the side-chain functionalized EDOT monomer. In this invention, a regenerated cellulose dialysis bag with a molecular weight cutoff of 1000 was used for product purification. Separation was achieved based on the molecular weight difference between the target product and impurities. The operation is simple and suitable for large-scale preparation. The side-chain functionalized EDOT monomer synthesized by reaction is composed of polyethylene glycol monoacrylate grafted with isophorone diisocyanate and thiophene[3,4-B]-1 with a number average molecular weight of 800-2200. The final product, 4-dioxan-2-methanol, has a number-average molecular weight greater than the molecular weight cutoff of the dialysis bag, and is therefore completely retained inside the dialysis bag. Various impurities remaining in the reaction system, including unreacted isophorone diisocyanate (molecular weight 222), thieno[3,4-B]-1,4-dioxan-2-methanol (molecular weight 172), and dibutyltin dilaurate (molecular weight 631), all have molecular weights below the 1000 cutoff threshold and can diffuse through the dialysis membrane into the external anhydrous methanol medium driven by the concentration gradient. By replacing the dialysis medium with fresh dialysis medium every 8 hours, all small molecule impurities can be gradually removed, resulting in a high-purity target monomer.

[0013] Preferably, the number average molecular weight of the polyethylene glycol monoacrylate in (1) is 800-2200.

[0014] Preferably, in (1), the molar ratio of isophorone diisocyanate, polyethylene glycol monoacrylate and thiophene[3,4-B]-1,4-dioxin-2-methanol is 1.05-1.1:1:1-1.1.

[0015] Preferably, the catalyst in (1) is dibutyltin dilaurate, and the amount used is 0.3%-0.8% of the mass of thieno[3,4-B]-1,4-dioxan-2-methanol.

[0016] Preferably, the dialysis bag in (2) is a regenerated cellulose dialysis bag with a molecular weight cutoff of 1000.

[0017] Preferably, in step (2), fresh anhydrous methanol is replaced every 8 hours during the dialysis process.

[0018] Furthermore, the present invention also provides a method for preparing a stretchable PEDOT electrode flexible dimming film, comprising the following steps: S1. The thermoplastic polyurethane film is passed through an oxygen plasma treatment machine with a treatment power of 80-120W and a treatment time of 60-120s to introduce active hydroxyl groups on the film surface, thereby obtaining an activated elastic substrate. S2. Dissolve EDOT monomer, side-chain functionalized EDOT monomer, and polyanionic dopant in deionized water to prepare a mixture with a mass fraction of 0.8%-1.5%. Add ammonium persulfate and ferric sulfate to the mixture, stir evenly, and transfer to a reactor. Polymerize at 25-35℃ in the dark for 8-12 hours. After the reaction is complete, add ion exchange resin accounting for 20-30% of the mass of the mixture for adsorption and purification. After filtering to remove the resin, adjust the solid content to 1.0%-1.5% to obtain the modified PEDOT composite aqueous dispersion. S3. The modified PEDOT composite aqueous dispersion was uniformly coated on the surfaces of two activated elastic substrates, and after hot air drying and vacuum drying, the first and second conductive electrode layers with a dry film thickness of 80-220 nm were obtained. S4. Nematic liquid crystal, polyurethane acrylate prepolymer, photoinitiator, polymer microsphere spacer particles, chiral agent and dichroic dye are stirred evenly under room temperature and light-protected conditions, and then vacuum degassed to obtain a dye liquid crystal mixture. S5. The dye liquid crystal mixture is coated onto the surface of the first conductive electrode layer, and the coating thickness is controlled to be 15-25μm. The second conductive electrode layer is aligned and attached to ensure that the electrode surfaces are facing each other. After the air bubbles are removed, ultraviolet light is used to complete the curing. After the edges are sealed, a stretchable PEDOT electrode flexible dimming film is obtained.

[0019] Preferably, the mass ratio of polyanionic dopant to total polymeric monomer in S2 is 2-3:1, wherein the polymeric monomer refers to EDOT monomer and side-chain functionalized EDOT monomer.

[0020] Preferably, the molar ratio of ammonium persulfate to total polymeric monomers in S2 is 1.05-1.2:1.

[0021] Preferably, the amount of ferric sulfate used in S2 is 0.2%-0.5% of the total molar amount of polymeric monomers.

[0022] Preferably, the ion exchange resin in S2 is a system of strong acid cation exchange resin and weak base anion exchange resin mixed in a mass ratio of 1:1, and the adsorption treatment time is 2-5 hours.

[0023] Preferably, in step S3, the coating is applied using rod coating or slot coating, and the coating speed is 1-3 m / min.

[0024] Preferably, the hot air drying conditions in S3 are drying at 50-60℃ for 2-4 minutes.

[0025] Preferably, the vacuum drying conditions in S3 are drying at 40-60℃ for 1.5-2.5h. Preferably, the intensity of the ultraviolet light in S5 is 80-120 mW / cm². 2 The curing time is 50-90 seconds.

[0026] Preferably, the working mechanism of the stretchable PEDOT electrode flexible dimming film of the present invention is explained as follows: Conventional PEDOT:PSS conductive films are brittle because there is a strong π-π stacking effect between the conjugated backbone of PEDOT, and the molecules are tightly packed, making it difficult for relative slippage to occur. At the same time, the PSS polystyrene backbone itself, as a continuous phase, is highly rigid, and the conductive domains are easily broken directly under tensile deformation, resulting in a rapid decay of conductivity. This invention improves material toughness at the molecular level by covalently grafting long-chain polyether side chains onto the PEDOT main chain. The uniformly distributed polyether side chains insert between the PEDOT conjugated molecular chains, physically widening the interchain distance, weakening the π-π stacking force, and lowering the energy barrier for relative slippage of the main chain. Under normal conditions, the polyether side chains exist in a randomly coiled state. When the film is subjected to tensile stress, the coiled side chains gradually unwind, absorbing deformation energy through entropic elasticity, preventing stress from directly concentrating on the rigid PEDOT conjugated main chain. Simultaneously, physical entanglement can form between the long side chains, evenly distributing stress to more molecular chain segments and reducing the probability of conductive network breakage caused by localized stress concentration. When combined with a sodium polystyrene sulfonate (PSSNa) / sulfonated styrene-ethylene-butene-styrene block copolymer (sulfonated SEBS) composite doping system, the sulfonated polystyrene hard segments of sulfonated SEBS contain polar sulfonic acid groups, which can form hydrogen bonds with the ether oxygen bonds of the PEDOT side chain polyether segments through polar interactions, while simultaneously interacting with positively charged... The electrostatic attraction generated by the conjugated PEDOT backbone provides excellent thermodynamic compatibility with polar polyether side chains and PSS doped systems, allowing it to be uniformly integrated into the polar continuous phase surrounding the conductive domains. In contrast, the ethylene-butene elastic block of sulfonated SEBS has a saturated nonpolar alkane structure with low solubility parameters and lacks polar interaction sites. It is thermodynamically incompatible with polar polyether side chains and the PEDOT conductive system, leading to spontaneous microphase separation and the formation of nanoscale elastic dispersed domains within the continuous phase. These elastic domains can synergistically toughen with the polyether side chains on the PEDOT backbone: during tensile deformation, the coiled polyether side chains absorb some deformation energy through conformational expansion, while the dispersed elastic domains further dissipate stress through reversible deformation. Simultaneously, the anchoring effect of the sulfonated polystyrene hard segments effectively transfers stress to the elastic phase, preventing stress concentration that could lead to brittle fracture of the PEDOT conductive network. Ultimately, this significantly improves the tensile strain and conductivity stability of the electrode at fracture while maintaining conductivity.

[0027] In conventional flexible PDLC dimming films, the electrodes and dimming layer are only physically bonded, resulting in weak interfacial adhesion. During repeated stretching cycles, electrode detachment and interfacial delamination are highly likely, representing the primary failure mode for stretchable PDLC devices. This invention utilizes the UV curing process of PDLC to simultaneously achieve interfacial chemical bonding, eliminating the need for additional processing steps. Under UV irradiation, the photoinitiator in the PDLC premix decomposes to generate free radicals, triggering free radical chain polymerization of the double bonds in the polyurethane acrylate prepolymer, gradually forming a three-dimensional cross-linked polymer network. Simultaneously, the acrylate double bonds intact at the ends of the PEDOT side chains act as comonomers, directly participating in the free radical polymerization reaction and covalently integrating into the PDLC's polymer cross-linked network. This results in interlayer adhesion far exceeding that of physical bonding and adhesive structures. During stretching deformation, stress can be uniformly transferred between the electrodes and dimming layer through covalent bonds, avoiding stress concentration at the interface. This solves the interfacial delamination failure problem in stretchable PDLC devices and significantly improves the mechanical cycle life of the devices.

[0028] The dimming function is based on the refractive index matching principle of polymer-dispersed liquid crystals. Simultaneously, chiral agents, dichroic dyes, and spacer particles synergistically optimize the dimming effect and film uniformity. During UV curing, the polyurethane acrylate prepolymer and the nematic liquid crystal undergo induced phase separation, forming a continuous polymer three-dimensional network encapsulating the liquid crystal microdroplets. The polymer microsphere spacer particles control the dimming layer thickness, ensuring the dimming uniformity of large-area films. Without an applied electric field, the molecules within the liquid crystal microdroplets are randomly arranged, and their ordinary light refractive index does not match the refractive index of the polymer matrix, resulting in strong scattering of incident visible light. The chiral agent induces the liquid crystal to form a spiral. The arrangement of the dichroic dye molecules further enhances the scattering effect. Simultaneously, the dichroic dye molecules are randomly distributed with the liquid crystal, consuming incident light energy through biaxial absorption, further reducing the off-state transmittance and improving the on-state contrast. After applying a matching external electric field, the liquid crystal molecules align along the direction of the electric field, and their ordinary light refractive index tends to match the refractive index of the polymer matrix. At the same time, the dichroic dye molecules are synchronously aligned with the liquid crystal along the electric field, the light absorption effect is weakened, and the incident visible light can pass through the thin film smoothly, and the device exhibits a highly transparent state. After the electric field is removed, the liquid crystal molecules return to their disordered arrangement under the interfacial anchoring effect of the polymer network, and the thin film returns to the scattering dark state, thereby realizing the function of electronically controlled dimming.

[0029] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention copolymerizes side-chain functionalized EDOT derivatives with ordinary EDOT, and covalently grafts flexible polyether side chains onto the conjugated PEDOT backbone. This weakens the strong π-π stacking effect of the conjugated backbone at the molecular level, endowing the conductive film with intrinsic tensile toughness. Combined with a composite doping system of sulfonated SEBS and PSS, synergistic toughening is achieved through the microscopic phase separation of elastic domains. While maintaining good conductivity and optical transparency, it improves the fracture tensile strain and conductivity stability under deformation of the electrode, adapting to the application requirements of stretchable optoelectronic devices.

[0030] 2. This invention utilizes the UV curing process of the PDLC dimming layer to simultaneously achieve covalent bonding between the electrode and the dimming layer. Without additional processing steps, an integrated structure with molecular-level riveting can be formed at the interface of the two phases. The interlayer adhesion is much higher than that of conventional physical bonding systems. During tensile deformation, stress can be uniformly transferred through covalent bonds, avoiding stress concentration at the interface. This solves the problems of electrode detachment and interface delamination failure during repeated deformation of stretchable PDLC devices, effectively improving the mechanical cycle life of the device.

[0031] 3. The stretchable dimming film of the present invention achieves synergistic optimization of mechanical and electro-optical properties while ensuring excellent electro-control dimming function. It has sufficient scattering and high contrast in the off state, good transparency and low driving voltage in the on state, and excellent dimming uniformity. Compared with existing flexible PDLC products, the performance degradation of the device under repeated stretching and bending deformation is reduced. It can be adapted to diverse application scenarios such as curved surface bonding, wearable electronics, and flexible smart windows, thus expanding the application scope of PDLC dimming film.

[0032] 4. The side-chain functionalized EDOT monomer of the present invention achieves stepwise directional synthesis based on the difference in group activity of isophorone diisocyanate, without the need to introduce additional protection-deprotection steps. It has high reaction selectivity, uniform product structure, and small molecule impurities can be effectively removed by dialysis purification. The operation is simple and easy to scale up. The overall preparation process is compatible with existing PEDOT-based PDLC production lines, without the need for new complex equipment. The process cost is controllable and has good potential for industrial application. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0034] Preparation Example 1: A specific method for preparing side-chain functionalized EDOT derivatives, including the following steps: (1) Under nitrogen protection, 1.05 mol of isophorone diisocyanate was added to 400 mL of anhydrous tetrahydrofuran. Stirring was started, and the temperature was raised to 35±2℃. 1 mol of polyethylene glycol monoacrylate with a number average molecular weight of 800 was added dropwise. During the dropwise addition, the reaction temperature was maintained at no more than 38℃. After the dropwise addition was completed, the reaction was kept at the temperature for 4 h. After cooling to room temperature, 1 mol of thieno[3,4-b]-1,4-dioxin-2-methanol and dibutyltin dilaurate were added. The amount of dibutyltin dilaurate was 0.3% of the mass of thieno[3,4-b]-1,4-dioxin-2-methanol. The temperature was raised to 50℃ under stirring and the reaction was carried out for 6 h. After the reaction was completed, the solvent was removed by vacuum distillation to obtain the crude product. (2) The crude product was completely dissolved in anhydrous methanol and transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 1000. The bag was sealed at both ends and placed in a dialysis tank containing anhydrous methanol. Dialysis was performed at room temperature in the dark for 24 hours. Fresh anhydrous methanol was replaced every 8 hours during the dialysis process. After the dialysis was completed, the solution in the bag was removed, and methanol was removed by vacuum distillation. After drying, the side-chain functionalized EDOT monomer was obtained.

[0035] Preparation Example 2: A specific method for preparing side-chain functionalized EDOT derivatives, including the following steps: (1) Under nitrogen protection, 1.08 mol of isophorone diisocyanate was added to 500 mL of anhydrous tetrahydrofuran. Stirring was started, and the temperature was raised to 35±2℃. 1 mol of polyethylene glycol monoacrylate with a number average molecular weight of 1500 was added dropwise. During the dropwise addition, the reaction temperature was maintained at no more than 38℃. After the dropwise addition was completed, the reaction was kept at the temperature for 5 h. After cooling to room temperature, 1.05 mol of thieno[3,4-b]-1,4-dioxin-2-methanol and dibutyltin dilaurate were added. The amount of dibutyltin dilaurate was 0.55% of the mass of thieno[3,4-b]-1,4-dioxin-2-methanol. The temperature was raised to 55℃ under stirring and the reaction was carried out for 8 h. After the reaction was completed, the solvent was removed by vacuum distillation to obtain the crude product. (2) The crude product was completely dissolved in anhydrous methanol and transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 1000. The bag was sealed at both ends and placed in a dialysis tank containing anhydrous methanol. Dialysis was performed at room temperature in the dark for 30 hours. Fresh anhydrous methanol was replaced every 8 hours during the dialysis process. After the dialysis was completed, the solution in the bag was removed, and methanol was removed by vacuum distillation. After drying, the side-chain functionalized EDOT monomer was obtained.

[0036] Preparation Example 3: A specific method for preparing side-chain functionalized EDOT derivatives, including the following steps: (1) Under nitrogen protection, 1.1 mol of isophorone diisocyanate was added to 600 mL of anhydrous tetrahydrofuran. Stirring was started, and the temperature was raised to 35±2℃. 1 mol of polyethylene glycol monoacrylate with a number average molecular weight of 2200 was added dropwise. During the dropwise addition, the reaction temperature was maintained at no more than 38℃. After the dropwise addition was completed, the reaction was kept at the temperature for 6 h. After cooling to room temperature, 1.1 mol of thieno[3,4-b]-1,4-dioxane-2-methanol and dibutyltin dilaurate were added. The amount of dibutyltin dilaurate was 0.8% of the mass of thieno[3,4-b]-1,4-dioxane-2-methanol. The temperature was raised to 60℃ under stirring and the reaction was carried out for 10 h. After the reaction was completed, the solvent was removed by vacuum distillation to obtain the crude product. (2) The crude product was completely dissolved in anhydrous methanol and transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 1000. The bag was sealed at both ends and placed in a dialysis tank containing anhydrous methanol. Dialysis was performed at room temperature in the dark for 36 hours. Fresh anhydrous methanol was replaced every 8 hours during the dialysis process. After the dialysis was completed, the solution in the bag was removed, and methanol was removed by vacuum distillation. After drying, the side-chain functionalized EDOT monomer was obtained.

[0037] Comparative Preparation Example 1: The difference between Comparative Preparation Example 1 and Preparation Example 2 is that polyethylene glycol monoacrylate with a number average molecular weight of 1500 was replaced with hydroxyethyl acrylate. Meanwhile, in (2), column chromatography was used for separation and purification, the target mobile phase was collected, and the side-chain functionalized EDOT monomer was obtained after drying.

[0038] Comparative Preparation Example 2: The difference between Comparative Preparation Example 2 and Preparation Example 2 is that the polyethylene glycol monoacrylate with a number average molecular weight of 1500 was replaced with polyethylene glycol monoacrylate with a number average molecular weight of 4000.

[0039] Comparative Preparation Example 3: The difference between Comparative Preparation Example 3 and Preparation Example 2 is that polyethylene glycol monoacrylate with a number average molecular weight of 1500 is replaced with polyethylene glycol monomethyl ether with a number average molecular weight of 1500.

[0040] Example 1: A specific method for preparing a stretchable PEDOT electrode flexible dimming film, comprising the following steps: S1. Take a thermoplastic polyurethane film with a thickness of 30μm, place it in an oxygen plasma treatment machine, control the treatment power to 80W and the treatment time to 60s, introduce active hydroxyl groups on the film surface, and obtain an activated elastic substrate. S2. EDOT monomers and the side-chain functionalized EDOT monomers prepared in Preparation Example 1 were mixed in a molar ratio of 95:5, and dissolved together with a polyanionic dopant (a composite system of sodium polystyrene sulfonate and sulfonated styrene-ethylene-butene-styrene block copolymer in a mass ratio of 8:2) in deionized water to prepare a mixed solution with a total monomer mass fraction of 0.8% and a polyanionic dopant to total monomer mass ratio of 2:1. Ammonium persulfate and ferric sulfate were added to the mixed solution, with a molar ratio of ammonium persulfate to total monomer mass of 1.05:1 and an amount of ferric sulfate of 0.2% of the total monomer molar mass. After stirring evenly, the mixture was transferred to a reactor and polymerized at 25°C in the dark for 8 hours. After the reaction was completed, ion exchange resin (a system of strong acid cation exchange resin and weak base anion exchange resin mixed in a mass ratio of 1:1) was added at 20% of the mass of the mixed solution for adsorption and purification. The adsorption treatment time was 2 hours. After filtering to remove the resin, the solid content was adjusted to 1.0% to obtain a modified PEDOT composite aqueous dispersion. S3. The modified PEDOT composite aqueous dispersion was uniformly coated on the surfaces of two activated elastic substrates using a rod coating method at a coating speed of 1 m / min. After drying with hot air at 50℃ for 2 min and then under vacuum at 40℃ for 1.5 h, a first conductive electrode layer and a second conductive electrode layer with a dry film thickness of 80 nm were obtained. S4. 45g of nematic liquid crystal, 38g of polyurethane acrylate prepolymer, 1g of photoinitiator, 0.1g of polymethyl methacrylate microsphere spacer particles (average particle size of 15μm), 0.2g of chiral agent, and 0.5g of dichroic dye are stirred evenly at room temperature in the dark, and then vacuum degassed for 20min to obtain a dye liquid crystal mixture. S5. Apply the dye-liquid crystal mixture to the surface of the first conductive electrode layer, controlling the coating thickness to 15 μm. Align and attach the second conductive electrode layer, ensuring the electrode surfaces are facing each other. After removing air bubbles, apply light at an intensity of 80 mW / cm². 2 The film is cured by irradiation with 365nm ultraviolet light for 50 seconds. After edge sealing, a stretchable PEDOT electrode flexible dimming film is obtained.

[0041] Example 2: A specific method for preparing a stretchable PEDOT electrode flexible dimming film, comprising the following steps: S1. Take a thermoplastic polyurethane film with a thickness of 55μm, place it in an oxygen plasma treatment machine, control the treatment power to 100W and the treatment time to 90s, introduce active hydroxyl groups on the film surface, and obtain an activated elastic substrate. S2. The EDOT monomer and the side-chain functionalized EDOT monomer obtained in Preparation Example 2 were mixed at a molar ratio of 87.5:12.5, and dissolved together with the polyanionic dopant (a composite system of sodium polystyrene sulfonate and sulfonated styrene-ethylene-butene-styrene block copolymer at a mass ratio of 6.5:3.5) in deionized water to prepare a mixture with a total monomer mass fraction of 1.15% and a polyanionic dopant to total monomer mass ratio of 2.5:1; ammonium persulfate and ferric sulfate were added to the mixture. The molar ratio of the total monomers was 1.125:1, and the amount of ferric sulfate was 0.35% of the total monomer molar amount. After stirring evenly, the mixture was transferred to a reactor and polymerized at 30°C in the dark for 10 hours. After the reaction was completed, 25% of the mass of the mixture was added to the ion exchange resin (a system of strong acid cation exchange resin and weak base anion exchange resin mixed in a mass ratio of 1:1) for adsorption and purification. The adsorption treatment time was 3.5 hours. After filtering to remove the resin, the solid content was adjusted to 1.25% to obtain the modified PEDOT composite aqueous dispersion. S3. The modified PEDOT composite aqueous dispersion was uniformly coated on the surfaces of two activated elastic substrates using a rod coating method at a coating speed of 2 m / min. After drying with hot air at 55℃ for 3 min and then under vacuum at 50℃ for 2 h, a first conductive electrode layer and a second conductive electrode layer with a dry film thickness of 150 nm were obtained. S4. Mix 52.5g of nematic liquid crystal, 45g of polyurethane acrylate prepolymer, 2g of photoinitiator, 0.3g of polymethyl methacrylate microsphere spacers (average particle size of 20μm), 0.6g of chiral agent, and 1.25g of dichroic dye at room temperature in the dark, and then vacuum degas for 30min to obtain a dye liquid crystal mixture. S5. Apply the dye-liquid crystal mixture to the surface of the first conductive electrode layer, controlling the coating thickness to 20 μm. Align and attach the second conductive electrode layer, ensuring the electrode surfaces are facing each other. After removing air bubbles, apply light at an intensity of 100 mW / cm². 2 The film is cured by irradiation with 365nm ultraviolet light for 70 seconds. After edge sealing, a stretchable PEDOT electrode flexible dimming film is obtained.

[0042] Example 3: A specific method for preparing a stretchable PEDOT electrode flexible dimming film, comprising the following steps: S1. Take a thermoplastic polyurethane film with a thickness of 80μm, place it in an oxygen plasma treatment machine, control the treatment power to 120W and the treatment time to 120s, introduce active hydroxyl groups on the surface of the film, and obtain an activated elastic substrate. S2. The EDOT monomer and the side-chain functionalized EDOT monomer obtained in Preparation Example 3 were mixed in a molar ratio of 80:20, and dissolved together with the polyanionic dopant (a composite system of sodium polystyrene sulfonate and sulfonated styrene-ethylene-butene-styrene block copolymer in a mass ratio of 5:5) in deionized water to prepare a mixed solution with a total monomer mass fraction of 1.5% and a polyanionic dopant to total monomer mass ratio of 3:1. Ammonium persulfate and ferric sulfate were added to the mixed solution, with a molar ratio of ammonium persulfate to total monomer mass of 1.2:1 and an amount of ferric sulfate of 0.5% of the total monomer molar mass. After stirring evenly, the mixture was transferred to a reactor and stirred and polymerized at 35°C in the dark for 12 hours. After the reaction was completed, ion exchange resin (a system of strong acid cation exchange resin and weak base anion exchange resin mixed in a mass ratio of 1:1) was added at 30% of the mass of the mixed solution for adsorption and purification. The adsorption treatment time was 5 hours. After filtering to remove the resin, the solid content was adjusted to 1.5% to obtain the modified PEDOT composite aqueous dispersion. S3. The modified PEDOT composite aqueous dispersion was uniformly coated on the surfaces of two activated elastic substrates using a slit coating method at a speed of 3 m / min. After drying with hot air at 60℃ for 4 min and then under vacuum at 60℃ for 2.5 h, a first conductive electrode layer and a second conductive electrode layer with a dry film thickness of 220 nm were obtained. S4. Mix 60g of nematic liquid crystal, 52g of polyurethane acrylate prepolymer, 3g of photoinitiator, 0.5g of polymethyl methacrylate microsphere spacers (average particle size of 25μm), 1g of chiral agent, and 2g of dichroic dye at room temperature in the dark, and then vacuum degas for 40min to obtain a dye liquid crystal mixture. S5. Apply the dye-liquid crystal mixture to the surface of the first conductive electrode layer, controlling the coating thickness to 25 μm. Align and attach the second conductive electrode layer, ensuring the electrode surfaces are facing each other. After removing air bubbles, apply light at an intensity of 120 mW / cm². 2 The film is cured by irradiation with 365nm ultraviolet light for 90 seconds. After edge sealing, a stretchable PEDOT electrode flexible dimming film is obtained.

[0043] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that the side-chain functionalized EDOT monomer obtained in Preparation Example 2 is not added.

[0044] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that sulfonated styrene-ethylene-butene-styrene block copolymer is not added to the polyanionic dopant.

[0045] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the side-chain functionalized EDOT monomer prepared in Example 2 was replaced with the side-chain functionalized EDOT monomer prepared in Comparative Example 1.

[0046] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that the side-chain functionalized EDOT monomer prepared in Example 2 was replaced with the side-chain functionalized EDOT monomer prepared in Comparative Example 2.

[0047] Comparative Example 5: The difference between Comparative Example 5 and Example 2 is that the side-chain functionalized EDOT monomer prepared in Example 2 was replaced with the side-chain functionalized EDOT monomer prepared in Comparative Example 3.

[0048] Performance testing: 1. Electrode basic photoelectric performance test: The conductive electrode layers prepared in step S3 of each example and comparative example were used as test samples. The initial sheet resistance of the electrode was tested using a four-probe sheet resistance meter. Five different points were selected for testing the same sample and the arithmetic mean was taken. The transmittance of the sample at a visible light wavelength of 550nm was tested using a UV-Vis spectrophotometer. Before the test, a blank thermoplastic polyurethane substrate of the same batch was used for reference calibration. 2. Electrode tensile conductivity stability test: The single-sided conductive electrode layers prepared in step S3 of each embodiment and comparative example are cut into standard dumbbell-shaped test strips. Uniaxial tensile test is performed at a constant tensile rate using a universal testing machine until the electrode conductive path is completely broken. The tensile strain value at fracture is recorded. Another parallel strip is stretched to 30% fixed strain and held. The sheet resistance of the electrode under strain is tested and compared with the initial sheet resistance to calculate the sheet resistance retention rate. 3. Electrode-PDLC Layer Interface Adhesion Test: Using the complete dimming film devices prepared in each embodiment and comparative example as test samples, and referring to the paint film adhesion cross-cut adhesion test standard, a 10x10 grid was drawn on the surface of the electrode layer, ensuring that the scratch depth penetrated the electrode layer to reach the surface of the dimming layer. Standard test tape was applied smoothly to the grid area, and after removing air bubbles, it was quickly peeled off at a vertical angle. The percentage of electrode detachment area within the grid was observed, and the adhesion level was evaluated. The level judgment criteria are as follows: Level 0: No electrode detachment in the grid area, and the coating edge is intact and undamaged; Level 1: Total detachment area of ​​the grid does not exceed 5%, with only a small number of square edges slightly peeling off; Level 2: Total detachment area of ​​the grid 5%-15%, with some square edges detaching completely; Level 3: Total detachment area of ​​the grid 15%-35%, with continuous detachment areas; Level 4: Total detachment area of ​​the grid 35%-65%, with a large area of ​​electrodes detaching from the substrate; Level 5: Total detachment area of ​​the grid is higher than 65%, with almost all electrodes detached. 4. Electro-optic performance test of PDLC device: Connect the dimming film devices of each embodiment and the comparative example to a frequency-adjustable AC power supply. Use a haze meter to test the total haze of the device in the off state without an applied electric field and in the on state under the rated operating voltage. At the same time, record the driving voltage corresponding to the device when the haze in the on state drops to 10%. 5. Mechanical cycle stability test of the device: The dimming film devices of each embodiment and the comparative example were fixed on the reciprocating tensile test platform and subjected to 1000 cycles of tensile test under 20% tensile strain. After the cycle, the sheet resistance of the electrode and the haze in the switching state were tested again. The sheet resistance retention rate and haze difference retention rate were calculated by comparing with the initial performance. The experimental results are shown in Table 1.

[0049] Table 1 Performance Test Results Data Analysis: As can be seen from the test results in Table 1, the stretchable PEDOT electrode flexible dimming film prepared in the embodiments of the present invention exhibits excellent performance in terms of electrode basic photoelectric properties, tensile conductivity stability, interfacial bonding force, electro-optic modulation performance, and mechanical cycle reliability. Its overall performance is superior to that of existing conventional flexible PDLC dimming films. Among them, Example 2 achieves the best balance between conductivity, optical properties, tensile toughness, and cycle stability, and has the best comprehensive performance.

[0050] Regarding the basic photoelectric properties of the electrode, this invention achieves both good conductivity and visible light transmittance through the copolymerization modification of side-chain functionalized EDOT monomers combined with the synergistic effect of the polyanionic composite doping system. This fully meets the requirements for transparent electrodes used in dimming films. The appropriate polyether side-chain graft ratio can improve the compatibility between PEDOT and dopants, reduce film defects, and optimize the continuity of the conductive path. It also avoids significant disruption of the charge transport of the conjugated main chain due to excessive dilution of the insulating side chains, thus balancing film quality and conductivity efficiency. At the same time, the film has good uniformity, no obvious macroscopic phase separation, and the visible light transmittance is maintained at a high level. In the comparative examples without added side-chain functional monomers, PEDOT showed poor compatibility with the elastic dopant, resulting in severe phase separation in the film, poor continuity of conductive domains, and a significant increase in sheet resistance. The comparative examples using only sodium polystyrene sulfonate doping showed a slight decrease in film uniformity and slightly weaker conductivity than the composite-doped examples. The comparative examples with short side-chain modification showed limited improvement in PEDOT dispersion, more film defects, and poorer conductivity. In the comparative examples with ultra-long polyether side chains, the dilution effect and steric hindrance effect of the insulating side chains dominated the system, severely disrupting conjugated stacking and charge transition pathways, leading to a significant deterioration in sheet resistance. The comparative examples with methyl ether structures at the end of the side chains maintained essentially the same basic conductivity and light transmittance as the examples, as the polyether backbone structure remained unchanged.

[0051] Regarding the tensile conductivity stability of the electrode, this invention improves the brittleness of the PEDOT film by intrinsically toughening the polyether side chains through covalent grafting, combined with the synergistic toughening of the sulfonated SEBS elastic domains, from both molecular slip and energy dissipation aspects. This enhances the electrode's tensile strain at fracture and conductivity stability under deformation. The polyether side chains can insert between the conjugated main chains to weaken the π-π stacking forces and absorb deformation energy through conformational stretching. The elastic dispersed domains formed by composite doping can further dissipate stress, avoiding local stress concentration that could lead to the breakage of the conductive network, thus enabling the electrode to maintain an intact conductive path under large deformation. The comparative example without added side-chain functional monomers relied solely on elastic dopant blending for toughening, failing to weaken the rigid stacking of the PEDOT backbone at the molecular level. This resulted in lower electrode fracture strain and significant attenuation of conductivity under tensile deformation. The comparative example without sulfonated SEBS doping lacked the synergistic toughening effect of elastic domains, relying solely on bulk toughening via side chains, leading to significantly weaker tensile properties compared to the examples. The comparative example with short side-chain modification exhibited almost no toughening effect, with electrode brittleness approaching that of the pure PEDOT system. The comparative example with ultra-long polyether side chains easily induced microphase separation and stress concentration defects, resulting in a decrease in tensile toughness instead of an increase. The comparative example with methyl ether structures at the end of the side chains retained complete polyether side chains, and its bulk tensile properties showed no significant difference from the examples.

[0052] Regarding the adhesion between the electrode and the PDLC layer, this invention utilizes the UV curing process of PDLC to simultaneously achieve interfacial covalent bonding. The acrylate double bonds at the end of the side chains can directly participate in the free radical polymerization reaction of the dimming layer prepolymer, enabling the electrode and dimming layer to form an integrated structure with molecular-level bonding. The interlayer bonding strength is far higher than that of conventional physical bonding systems, improving the interface delamination problem of stretchable PDLC devices. The appropriate side chain length ensures that the terminal double bonds fully extend into the PDLC prepolymer phase, resulting in high reaction accessibility, sufficient interfacial crosslinking density, and optimal bonding effect. In the two comparative examples without active acrylate double bonds in the side chains, the electrode and dimming layer are only physically bonded, resulting in weak interfacial bonding and a significantly lower adhesion level. In the comparative examples with short side chain modification, the terminal double bonds have large steric hindrance, insufficient interfacial crosslinking density, and adhesion between physical bonding and complete covalent bonding. The remaining comparative examples retaining active double bonds can all achieve interfacial covalent crosslinking, and the adhesion is at the same level as the examples.

[0053] Regarding the electro-optic performance of PDLC devices, the dimming film of this invention exhibits excellent electro-controlled dimming effect, with sufficient off-state scattering and high contrast, good on-state transparency and low driving voltage. Its overall electro-optic performance surpasses that of conventional flexible PDLC devices. Excellent electrode conductivity ensures uniform in-plane electric field distribution and more complete liquid crystal molecule orientation, effectively reducing on-state haze and driving voltage. Simultaneously, the regular interface bonding ensures uniform PDLC-induced phase separation structure, improving off-state scattering efficiency and consistency in large-area dimming. Several comparative examples with poor electrode conductivity show larger in-plane voltage drops, insufficient effective electric field strength, and incomplete liquid crystal orientation, leading to increased on-state haze and a significant increase in driving voltage. Among these, the comparative example with ultra-long side chains exhibits the worst electrode conductivity, severely uneven electric field distribution, and the most significant degradation in electro-optic performance. The comparative example with no covalent bonding at the interface shows slightly poorer phase separation uniformity and a slight reduction in off-state haze, but the overall electro-optic performance is less affected by the interface than by conductivity.

[0054] Regarding the mechanical cycling stability of the device, the performance retention rate of the dimming film of this invention after repeated stretching cycles is higher than that of the prior art, and the service life is significantly improved. This is the result of the synergistic effect of intrinsic electrode toughening and interface covalent bonding. The intrinsically toughened conductive network can withstand repeated deformation without brittle fracture, and the covalently bonded interface can avoid interlayer delamination and electrode detachment during the stretching process. Together, they ensure the integrity of the conductive path and dimming structure during cycling, enabling the device to maintain stable conductivity and dimming performance over a long period of time. In the comparative example without side chain modification and interface bonding, both conductive network breakage and interface delamination occurred simultaneously during stretching cycles, resulting in the most severe performance degradation. In the comparative example lacking only sulfonated SEBS doping, the interface bonding was good, but the bulk toughening was insufficient, and the conductive network was significantly damaged after cycling, with a performance retention rate at a moderate level. In the comparative example without interface covalent bonding, even if the electrode body toughness was sufficient, electrode detachment was still prone to occur after stretching cycles, and the performance degradation rate was close to that of the prior art. In the comparative examples with short side chains and ultra-long side chains, the conductivity performance rapidly declined after cycling due to the poor stretching performance of the electrode body.

[0055] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A stretchable PEDOT electrode flexible dimming film, characterized in that, From bottom to top, it includes a first elastic substrate, a first conductive electrode layer, a PDLC dimming layer, a second conductive electrode layer, and a second elastic substrate; Both the first elastic substrate and the second elastic substrate are thermoplastic polyurethane films that have undergone oxygen plasma surface activation treatment, with a thickness of 30-80 μm; Both the first conductive electrode layer and the second conductive electrode layer are modified PEDOT composite electrode layers, which are prepared by aqueous phase oxidation copolymerization of EDOT monomer and side-chain functionalized EDOT derivative in a molar ratio of 80-95:5-20, followed by doping with a polyanionic dopant, with a thickness of 80-220 nm. The PDLC dimming layer is formed by UV curing of a dye liquid crystal mixture and has a thickness of 15-25μm. The dye-liquid crystal mixture comprises, by mass parts: 45-60 parts nematic liquid crystal, 38-52 parts polyurethane acrylate prepolymer, 1-3 parts photoinitiator, 0.1-0.5 parts polymer microsphere spacers, 0.2-1 parts chiral agent, and 0.5-2 parts dichroic dye. The side-chain functionalized EDOT derivative has the following chemical structural formula: 。 2. The stretchable PEDOT electrode flexible dimming film according to claim 1, characterized in that, The polyanionic dopant is a composite system of sodium polystyrene sulfonate and sulfonated styrene-ethylene-butene-styrene block copolymer in a mass ratio of 5-8:2-5.

3. The stretchable PEDOT electrode flexible dimming film according to claim 1, characterized in that, The polymer microsphere spacers are selected from at least one of polystyrene microspheres, polymethyl methacrylate microspheres, and polyurethane microspheres, with an average particle size of 15-25 μm.

4. The stretchable PEDOT electrode flexible dimming film according to claim 1, characterized in that, The preparation method of the side-chain functionalized EDOT derivative is as follows: (1) Under nitrogen protection, isophorone diisocyanate was added to anhydrous tetrahydrofuran, stirring was started, the temperature was raised to 35±2℃, and polyethylene glycol monoacrylate was added dropwise. During the dropwise addition, the reaction temperature was maintained at no more than 38℃. After the dropwise addition was completed, the reaction was kept at the temperature for 4-6 hours. After cooling to room temperature, thiophene[3,4-B]-1,4-dioxin-2-methanol and catalyst were added. Under stirring, the temperature was raised to 50-60℃ and the reaction was carried out for 6-10 hours. After the reaction was completed, the solvent was removed by vacuum distillation to obtain the crude product. (2) The crude product was completely dissolved in anhydrous methanol, transferred to a dialysis bag, sealed at both ends, and placed in a dialysis cylinder containing anhydrous methanol. Dialyze at room temperature in the dark for 24-36 hours. After dialysis, the solution in the bag was removed, methanol was removed by vacuum distillation, and dried to obtain the side-chain functionalized EDOT monomer.

5. The stretchable PEDOT electrode flexible dimming film according to claim 4, characterized in that, In (1), the number average molecular weight of polyethylene glycol monoacrylate is 800-2200; the molar ratio of isophorone diisocyanate, polyethylene glycol monoacrylate and thieno[3,4-B]-1,4-dioxin-2-methanol is 1.05-1.1:1:1-1.1; the catalyst is dibutyltin dilaurate, and the amount used is 0.3%-0.8% of the mass of thieno[3,4-B]-1,4-dioxin-2-methanol.

6. The stretchable PEDOT electrode flexible dimming film according to claim 4, characterized in that, The dialysis bag in (2) is a regenerated cellulose dialysis bag with a molecular weight cutoff of 1000; fresh anhydrous methanol is replaced every 8 hours during the dialysis process.

7. The method for preparing the stretchable PEDOT electrode flexible dimming film according to any one of claims 1-6, characterized in that, Includes the following steps: S1. The thermoplastic polyurethane film is passed through an oxygen plasma treatment machine with a treatment power of 80-120W and a treatment time of 60-120s to introduce active hydroxyl groups on the film surface, thereby obtaining an activated elastic substrate. S2. Dissolve EDOT monomer, side-chain functionalized EDOT monomer, and polyanionic dopant in deionized water to prepare a mixture with a mass fraction of 0.8%-1.5%. Add ammonium persulfate and ferric sulfate to the mixture, stir evenly, and transfer to a reactor. Polymerize at 25-35℃ in the dark for 8-12 hours. After the reaction is complete, add ion exchange resin accounting for 20-30% of the mass of the mixture for adsorption and purification. After filtering to remove the resin, adjust the solid content to 1.0%-1.5% to obtain the modified PEDOT composite aqueous dispersion. S3. The modified PEDOT composite aqueous dispersion was uniformly coated on the surfaces of two activated elastic substrates, and after hot air drying and vacuum drying, the first and second conductive electrode layers with a dry film thickness of 80-220 nm were obtained. S4. Nematic liquid crystal, polyurethane acrylate prepolymer, photoinitiator, polymer microsphere spacer particles, chiral agent and dichroic dye are stirred evenly under room temperature and light-protected conditions, and then vacuum degassed to obtain a dye liquid crystal mixture. S5. The dye liquid crystal mixture is coated onto the surface of the first conductive electrode layer, and the coating thickness is controlled to be 15-25μm. The second conductive electrode layer is aligned and attached to ensure that the electrode surfaces are facing each other. After the air bubbles are removed, ultraviolet light is used to complete the curing. After the edges are sealed, a stretchable PEDOT electrode flexible dimming film is obtained.

8. The method for preparing the stretchable PEDOT electrode flexible dimming film according to claim 7, characterized in that, In S2, the mass ratio of polyanionic dopant to total polymeric monomer is 2-3:1, where the polymeric monomer refers to EDOT monomer and side-chain functionalized EDOT monomer; the molar ratio of ammonium persulfate to total polymeric monomer is 1.05-1.2:1; the amount of ferric sulfate is 0.2%-0.5% of the molar amount of total polymeric monomer; the ion exchange resin is a system of strong acidic cation exchange resin and weak basic anion exchange resin mixed in a mass ratio of 1:1, and the adsorption treatment time is 2-5 hours.

9. The method for preparing the stretchable PEDOT electrode flexible dimming film according to claim 7, characterized in that, In the S3 process, the coating is applied using either rod coating or slot coating at a speed of 1-3 m / min; the hot air drying conditions are 50-60℃ for 2-4 min; and the vacuum drying conditions are 40-60℃ for 1.5-2.5 h.

10. The method for preparing the stretchable PEDOT electrode flexible dimming film according to claim 7, characterized in that, The intensity of ultraviolet light in S5 is 80-120 mW / cm². 2 The curing time is 50-90 seconds.

Images