Transparent conductive material, preparation method and application

Abstract

The present application relates to the field of organic electrochromic materials, and particularly relates to a transparent conductive material, a preparation method and application. The transparent conductive material simultaneously introduces two independent carbonyl groups in a molecular main chain, and realizes accurate coordination of energy level, polarity and charge transport performance through differential regulation of oxygen or nitrogen atoms. The polymer can be used as an ion storage layer, an electrode modification layer or an active functional layer in an electrochromic device, can realize fast reversible optical modulation at a low voltage (±1.0 V), has a high optical contrast (ΔT 550 > 65%), a short response time (<2 s) and excellent cycle stability (more than 3×10 4 times of cycles, a retention rate >95%), and has a wide application prospect in the fields of intelligent display, energy-saving buildings and flexible electronics.

Description

Technical Field

[0001] This invention relates to the field of organic electrochromic materials, specifically to a transparent conductive material, its preparation method, and its application. Background Technology

[0002] Organic electrochromic materials, capable of reversible color changes at low voltages, have shown great application potential in fields such as smart dimming windows, flexible displays, and energy-efficient buildings. In recent years, researchers have developed various electrochromic polymer systems based on conjugated backbones through molecular design and energy level modulation. However, existing materials generally suffer from a difficulty in achieving a balance between performance and energy levels: one type of oxygen-containing polymer, primarily composed of ester or lactone structures, exhibits good solubility and flexibility, but has limited electron transport capabilities and poor electrochemical stability, easily degrading under long-term cycling or high-temperature and high-humidity conditions; another type of nitrogen-containing polymer, primarily composed of amide or imide structures, possesses high electron affinity and good stability, but suffers from poor film-forming properties, insufficient interfacial compatibility, and often requires high processing temperatures and complex post-processing techniques.

[0003] Recent studies have shown that the number of carbonyl groups in the polymer backbone and their interaction with heteroatoms (O or N) have a decisive influence on molecular energy level structure, polarity distribution, and ion transport properties. For example, multiple studies in JACS (2022), Macromolecules (2024), and Advanced Functional Materials (2023–2024) have indicated that the stability of n-type polymers depends on the electronic coupling region formed by carbonyl groups and heteroatoms in the molecular backbone. Related studies in Angewandte Chemie (2024–2025) and Nature Communications (2024) further confirm that adjusting the electron density of heteroatoms can significantly improve doping efficiency and carrier mobility. However, most of these studies focus on single-type structural systems, namely either oxygen-containing ester polymers or nitrogen-containing amide or imide polymers, and have not yet systematically explored the possibility of synergistic effects between the two types of structures within the same molecular framework.

[0004] In electrochromic devices, the matching between the ion storage layer and the electrode interface is particularly critical. Although traditional PEDOT:PSS or n-PBDF materials possess certain conductivity and stability, their single polarity distribution makes it difficult to simultaneously meet the comprehensive performance requirements of low voltage drive, high optical contrast, and long cycle life. Summary of the Invention

[0005] To address the aforementioned problems, the transparent conductive material provided by this invention can simultaneously introduce two independent carbonyl groups into the molecular backbone, and through differential regulation of oxygen or nitrogen atoms, achieve precise synergy of energy levels, polarity, and charge transport performance, thereby constructing an electrochromic polymer with both high stability and high responsiveness.

[0006] This invention provides a transparent conductive material with the following molecular formula:

[0007]

[0008] A is O or NR; R is selected from H, ether chain, fluorinated ether chain, phosphate ester chain or quaternary ammonium salt chain;

[0009] n is an integer between 5 and 500.

[0010] In a preferred embodiment of the present invention, R is selected from the following:

[0011]

[0012] Where R1, R2, and R3 are independent alkyl groups;

[0013] X is selected from fluorine, chlorine, bromine, iodine, or phosphate;

[0014] y is an integer from 1 to 10.

[0015] In a preferred embodiment of the present invention, the structure is selected from the following:

[0016] .

[0017] In another aspect of the present invention, a method for preparing the aforementioned transparent conductive material is also provided, comprising the following steps:

[0018]

[0019] Specifically, the steps include the following:

[0020] S1, 2,5-diamino-1,4-phenyldiboronic acid (A-1) and diethyl 2,3-dibromofumarate (A-2) were polymerized by Suzuki coupling reaction in a 1:1 molar ratio under a catalyst to obtain intermediate A-3;

[0021] S2. The intermediate A-3 undergoes transesterification or ester-aminolation under strong acid catalysis to form a lactone or lactam compound A-4.

[0022] In a preferred embodiment of the present invention, the following steps are further included:

[0023] S3. The lactam compound A-4 reacts with a halogenated compound to give the target product A-5. The reaction process is as follows:

[0024] .

[0025] In a third aspect of the invention, the application of the aforementioned transparent conductive material in electrochromic devices is also provided.

[0026] In a preferred embodiment of the present invention, the electrochromic device is a p-n type complementary electrochromic device, with ProDOT or its derivative as the p-type electrochromic layer and the transparent conductive material as the n-type ion storage layer.

[0027] In a preferred embodiment of the present invention, the electrochromic device further includes a gel electrolyte serving as an ion-conducting medium, located between the p-type electrochromic layer and the n-type ion storage layer.

[0028] The materials provided by this invention can achieve different molecular configurations dominated by ester bonds or imide bonds by adjusting the types of X and R. The oxygen-containing structure endows the polymer with excellent solubility and film-forming properties, while the nitrogen-containing structure enhances electron affinity and thermal stability. These two types of structures exhibit a significant synergistic effect in copolymerization or composite states. These polymers can be used as ion storage layers, electrode modification layers, or active functional layers in electrochromic devices, achieving rapid and reversible optical modulation at relatively low voltages (±1.0 V) and exhibiting high optical contrast (ΔT). 550 >65%, short response time (<2s), and excellent cycling stability (over 3×10⁻⁶). 4 The retention rate after one cycle is >95%.

[0029] Furthermore, the material of this invention exhibits excellent environmental adaptability under conditions of 85℃ / 85% RH, UV aging, and salt spray, and is highly compatible with ProDOT-type electrochromic layers and PEDOT:PSS electrodes. This polymer system, while improving device performance, still possesses good processing adaptability and solution processability, and can be fabricated using various film-forming processes such as spin coating, spraying, and printing. In summary, this invention, through the design of a dual carbonyl linkage unit at the structural level, provides a new molecular engineering path for achieving low-voltage driven, highly stable, and scalable electrochromic polymers, with broad application prospects in smart displays, energy-efficient buildings, and flexible electronics. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0031] The present invention will be further described in detail below with reference to the embodiments.

[0032] Example 1: Synthesis of representative compound T-1

[0033]

[0034] Under nitrogen protection, 0.1 mol (19.7 g) of (2,5-hydroxy-1,4-phenylene) diboronic acid (T-1-1) and 0.1 mol (32.9 g) of diethyl 2,3-dibromofumarate (T-1-2) were dissolved in a mixed solvent of toluene, ethanol and deionized water in a volume ratio of 5:1:1. K2CO3 (3 equivalents) was added as a base and Pd(PPh3)4 (1 mol%) as a catalyst. After degassing three times under nitrogen atmosphere, the mixture was refluxed and stirred at 85–90 °C for 24 h to carry out Suzuki coupling polymerization. After the reaction was completed, the mixture was cooled to room temperature, neutralized with dilute hydrochloric acid and washed with water to remove inorganic salts. The organic layer was then concentrated under reduced pressure and slowly added dropwise to a large amount of methanol to precipitate the polymer. After filtration, the polymer was washed alternately with methanol and acetone and dried under vacuum at 60 °C to obtain a dark solid intermediate T-1-3 (ester) with a yield of about 70%. 1 H NMR (500 MHz, Chloroform ) δ 6.96(s, 1H), 6.81 (s, 1H), 5.43 (s, 1H), 4.09 (dq, J = 85.0, 22.0 Hz, 2H), 1.16(dt, J = 90.1, 22.0 Hz, 3H).

[0035] FT-IR spectrum at 1735 cm⁻¹ -1 The presence of a distinct C=O absorption peak at the ester indicates that the Suzuki coupling polymerization proceeded successfully.

[0036] The T-1-3 (10.0 g) obtained in the previous step was placed under nitrogen protection, and m-cresol / NMP (1:1, 100 mL) was added as a high-boiling solvent. Acetic anhydride (8–10 equivalents based on the diester in the repeating unit) and a small amount of sodium acetate / imidazolium were added as a catalytic dehydrating agent. The mixture was stirred at 140–160 °C for 6–8 h to first complete the lactone reaction of adjacent hydroxyl groups on the ester group and release ethanol. Then, the temperature was raised to 180 °C and the reaction was continued for 1–2 h to promote cyclization and dehydration to generate an aromatic lactone ring. After the reaction was completed, the mixture was cooled, and the solvent and excess acetic anhydride were removed under reduced pressure. The concentrate was slowly added dropwise to a large amount of methanol to precipitate the product. The product was filtered and thoroughly washed with methanol / acetone. The product was then dried under vacuum at 60 °C to obtain the target polymer T-1 as a light yellow solid (yield 80%). 1 ¹H NMR (500MHz, Chloroform) δ 9.34 (s, 1H), 7.36 (s, 1H). Molecular weight was determined by gel permeation chromatography (GPC) under the following conditions: mobile phase DMF + 0.05 M LiBr, column temperature 40 °C, flow rate 1.0 mL / min. -1 Calibration was performed using polystyrene (PS) standards, with an RI detector. Mn = 2.8 × 10⁻⁶ 4 g mol -1 Mw = 6.6 × 10 4 g mol -1 , Ð =2.36.

[0037] FT-IR C=O of ester (approximately 1735 cm⁻¹) -1 Absorption was significantly reduced, and a characteristic peak of lactone C=O appeared (approximately 1775 cm⁻¹). -1 ) and C–O–C absorption (approximately 1235 cm⁻¹) -1 This indicates that the intramolecular esterification reaction was successfully completed.

[0038] Example 2: Synthesis of representative compound T-2

[0039] Under nitrogen protection, 0.1 mol (19.5 g) of (2,5-diamino-1,4-phenylene)diboronic acid (T-2-1) and 0.1 mol (32.9 g) of diethyl 2,3-dibromofumarate (T-2-2) were dissolved in a mixed solvent of toluene, ethanol and deionized water in a volume ratio of 5:1:1. K2CO3 (3 equivalents) was added as a base and Pd(PPh3)4 (1 mol%) as a catalyst. After degassing three times under nitrogen atmosphere, the mixture was refluxed and stirred at 85–90 °C for 24 h to carry out Suzuki alternating copolymerization. After the reaction was completed, the mixture was cooled to room temperature, neutralized with dilute hydrochloric acid, and washed with water to remove inorganic salts. The organic layer was concentrated under reduced pressure and then slowly added dropwise to a large amount of methanol to precipitate the polymer. The polymer was filtered, washed with methanol and acetone, and dried under vacuum at 60 °C to obtain a dark solid intermediate T-2-3 (ester), with a yield of about 70%. 1 H NMR (500 MHz, Chloroform ) δ 6.66 (s,1H), 6.35 (s, 1H), 4.09 (dq, J = 85.0, 22.0 Hz, 4H), 3.06 (d, J = 44.1 Hz, 4H), 1.16 (dt, J = 90.1, 22.0 Hz, 6H).

[0040] The product was detected by FT-IR at 1735 cm⁻¹. -1 The presence of a distinct ester C=O absorption peak indicates that the Suzuki polymerization reaction proceeded smoothly.

[0041] The T-2-3 (10.0 g) obtained in the previous step was placed under nitrogen protection, and m-cresol / NMP (1:1, 100 mL) was added as a high-boiling solvent. Acetic anhydride (8–10 equivalents based on the diester in the repeating unit) and a small amount of sodium acetate / imidazolium were added as catalytic dehydrating agents. The mixture was stirred at 140–160 °C for 6–8 h to first complete the intramolecular amidation of the ester group by the adjacent amino group and release ethanol. Then, the temperature was raised to 180 °C and the reaction was continued for 1–2 h to promote cyclization and dehydration to generate a six-membered lactam ring structure. After the reaction was completed, the mixture was cooled, and the solvent and excess acetic anhydride were removed under reduced pressure. The concentrate was slowly added dropwise to a large amount of methanol to precipitate the product. The product was filtered and thoroughly washed with methanol / acetone. The product was then dried under vacuum at 60 °C to obtain the target polymer T-2 as a dark brown solid (yield 89%). 1¹H NMR (500 MHz, Chloroform) δ 9.57 (s, 1H), 7.13 (s, 1H). Molecular weight was determined by gel permeation chromatography (GPC) under the following conditions: mobile phase DMF + 0.05 M LiBr, column temperature 40 °C, flow rate 1.0 mL / min. -1 Calibration was performed using polystyrene (PS) standards, with an RI detector. Mn = 3.2 × 10⁻⁶ 4 g mol -1 Mw = 7.5 × 10 4 gmol -1 Ð = 2.34

[0042] FT-IR shows that the ester has C=O ( 1735 cm -1 The absorption disappears, and the characteristic double peak of lactam C=O appears. 1710 and 1675 cm -1 ) and C–N absorption ( 1370 cm -1 This proves that the six-membered ring lactam structure was successfully formed.

[0043] Example 3: Synthesis of representative compound T-3

[0044]

[0045] Under nitrogen protection, dissolve 1.0 g of T-2 (a lactam polymer, approximately 2.0 mmol based on N–H = 1 in a repeating unit) in anhydrous DMF (containing 5–10 mg / mL of solids). -1NaH (60% dispersion, 3.0 mmol, 1.5 equivalents / repeat unit) was added in batches under ice bath and stirred for 20–30 min for deprotonation; then 1-bromo-2-(2-(2-methoxyethoxy)ethoxy)ethane (T-3-1, 3.0 mmol, 1.5 equivalents) was added dropwise, and KI (5 mol%) could be added as a catalyst to promote halogen substitution. After removing the ice bath, the mixture was stirred at 50–60 °C for 10–12 h to complete N-alkylation. After the reaction was cooled, the remaining NaH was slowly quenched with 10 mL of anhydrous methanol, the solvent was removed under reduced pressure, and the concentrate was slowly added dropwise to ice-cold diethyl ether / methanol (4:1, 300–400 mL) to precipitate. The solid was collected by filtration and washed sequentially with methanol → acetonitrile → acetone to remove unreacted small molecules and salts. If necessary, Soxhlet extraction was performed (methanol / acetonitrile, 6 h each), and the product was dried under vacuum at 60 °C to obtain the target product T-3 (N-[–OCH2CH2OCH2CH2OCH3]-substituted lactam polymer) in 75% yield. 1 ¹H NMR (500 MHz, Chloroform) δ 9.76 (s, 1H), 7.18 (s, 1H), 4.23 – 2.85 (m, 30H). Molecular weight was determined by gel permeation chromatography (GPC) under the following conditions: mobile phase DMF + 0.05 M LiBr, column temperature 40 °C, flow rate 1.0 mL / min. -1 Calibration was performed using polystyrene (PS) standards, with an RI detector. Mn = 4.1 × 10⁻⁶ 4 g mol -1 Mw = 9.1 × 10 4 g mol -1 Ð = 2.22

[0046] N–H in FT-IR (≈3300 cm⁻¹) -1 The double peaks of amide C=O disappeared (≈1710 / 1675 cm⁻¹). -1 ) Retain and at ≈1100 cm -1 Significant C–O–C absorption was observed at the site.

[0047] Example 4: Synthesis of representative compound T-4

[0048]

[0049] Under nitrogen protection, dissolve 1.0 g of T-2 (a lactam polymer, approximately 2.0 mmol based on N–H = 1 in a repeating unit) in anhydrous DMF (containing 5–10 mg / mL of solids). -1 NaH (60% dispersion, 3.0 mmol, 1.5 equivalents / repeat unit) was added in batches under ice bath and stirred for 20–30 min for deprotonation; then 1-bromo-2-(2-(2-(trifluoromethoxy)ethoxy)ethoxy)ethane (T-4-1, 3.0 mmol, 1.5 equivalents) was added dropwise, and KI (5 mol%) could be added to promote substitution. After removing the ice bath, the mixture was stirred at 50–60 °C for 10–12 h to complete N-alkylation. After the reaction was cooled, the remaining NaH was slowly quenched with 10 mL of anhydrous methanol, the solvent was removed under reduced pressure, and the concentrate was slowly added dropwise to ice-cold diethyl ether / methanol (4:1, 300–400 mL) to precipitate. The solid was collected by filtration and washed sequentially with methanol → acetonitrile → acetone to remove unreacted small molecules and salts. If necessary, Soxhlet extraction was performed (methanol / acetonitrile, 6 h each), and the product was dried under vacuum at 60 °C to obtain the target product T-4 (N-containing trifluoromethoxy ether oxyalkyl substituted lactam polymer), with a yield of 78%. 1 H NMR (500MHz, Chloroform ) δ 9.63 (s, 1H), 7.17 (s, 1H), 4.11 – 3.78 (m, 2H), 3.73 –3.39 (m, 20H), 3.15 (t, J = 14.4 Hz, 2H). Molecular weight was determined by gel permeation chromatography (GPC) under the following conditions: mobile phase DMF + 0.05 M LiBr, column temperature 40 °C, flow rate 1.0 mL / min. -1 Calibration was performed using polystyrene (PS) standards, with an RI detector. Mn = 4.8 × 10⁻⁶ 4 g mol -1 Mw = 1.03 × 10 5 g mol -1 Ð = 2.15

[0050] N–H in FT-IR (≈3300 cm⁻¹) -1 The double peaks of amide C=O disappeared (≈1710 / 1675 cm⁻¹). -1 ) is retained, and significant C–O–C absorption (≈1100 cm⁻¹) is observed. -1 ) and C–F absorption (≈1210–1230 cm⁻¹) -1);¹ 9 F NMR showed a characteristic peak of –OCF3 at δ –56 to –58 ppm.

[0051] Example 5: Synthesis of representative compound T-5

[0052]

[0053] Under nitrogen protection, dissolve 1.0 g of T-2 (a lactam polymer, approximately 2.0 mmol based on N–H = 1 in a repeating unit) in anhydrous DMF / DMSO (1:1, solid content 5–10 mg·mL⁻¹). -1 Cs2CO3 (4.0 mmol, 2.0 equivalences / repeat unit) was added in batches under ice bath and stirred for 20–30 min for deprotonation; then ((5-bromopentyl)dimethyl-l4-azaneyl)methylium bromide (T-5-1, 3.0 mmol, 1.5 equivalences) was added in one batch, and 18-crown-6 (5 mol%) could be added to promote phase transfer. After removing the ice bath, the mixture was stirred at 60–70 °C for 12–16 h to complete N-alkylation. After cooling, the reaction was slowly quenched with 10 mL of anhydrous methanol, and the solvent was removed under reduced pressure. The concentrate was then slowly added dropwise to ice-cold acetone / diethyl ether (1:4, 300–400 mL) to precipitate. The solid was collected by filtration and washed sequentially with acetonitrile, methanol, and acetone to remove inorganic salts and unreacted small molecules. If necessary, Soxhlet extraction was performed (6 h each with acetonitrile and methanol). The product was dried under vacuum at 60 °C to obtain the target product T-5 (a lactam polymer with quaternary ammonium salt substitution in the side chain), with a yield of 73%. 1 H NMR (500 MHz, Chloroform) δ 9.80 (s, 1H), 7.08 (s, 1H), 4.33 (t, J = 21.4 Hz, 2H), 3.48 (t, J = 15.1Hz, 2H), 2.66 – 2.27 (m, 4H), 2.15 (s, 18H), 1.82 – 1.48 (m, 4H), 1.49 – 1.01 (m, 8H). Molecular weight was determined by gel permeation chromatography (GPC) under the following conditions: mobile phase DMF + 0.05 M LiBr, column temperature 40 °C, flow rate 1.0 mL / min. -1 Calibration was performed using polystyrene (PS) standards, with an RI detector. Mn = 5.0 × 10⁻⁶ 4 g mol -1Mw = 1.08 × 10 5 g mol -1 Ð = 2.16;

[0054] N–H in FT-IR (≈3300 cm⁻¹) -1 The double peaks of amide C=O disappeared (≈1710 / 1675 cm⁻¹). -1 ) Retained, and C–N appears. + Related absorption (≈950–1050 cm⁻¹) -1 ).

[0055] Example 6: Synthesis of representative compound T-6

[0056]

[0057] Under nitrogen protection, dissolve 1.0 g of T-2 (a lactam polymer, approximately 2.0 mmol based on N–H = 1 in a repeating unit) in anhydrous DMF (containing 5–10 mg / mL of solids). -1 NaH (60% dispersion, 3.0 mmol, 1.5 equivalents / repeat unit) was added in batches under ice bath and stirred for 20–30 min for deprotonation; then diethyl (5-bromopentyl)phosphonate (T-6-1, 3.0 mmol, 1.5 equivalents) was added dropwise, and KI (5 mol%) could be added to promote substitution. After removing the ice bath, the mixture was stirred at 50–60 °C for 10–12 h to complete N-alkylation. After the reaction was cooled, the remaining NaH was slowly quenched with 10 mL of anhydrous methanol, the solvent was removed under reduced pressure, and the concentrate was slowly added dropwise to ice-cold diethyl ether / methanol (4:1, 300–400 mL) to precipitate. The solid was collected by filtration and washed sequentially with methanol → acetonitrile → acetone to remove unreacted small molecules and salts. If necessary, Soxhlet extraction was performed (acetonitrile / methanol, 6 h each), and the product was dried under vacuum at 60 °C to obtain the target product T-6 (N-[–(CH2)5–P(O)(OEt)2] substituted lactam polymer), with a yield of 75–85%. 1 H NMR (500 MHz, Chloroform ) δ 9.80(s, 1H), 7.04 (s, 1H), 4.34 (t, J = 21.5 Hz, 2H), 3.49 (dt, J= 22.0, 15.8 Hz, 10H), 1.89 – 1.48 (m, 8H), 1.41 – 0.81 (m, 20H). Molecular weight was determined by gel permeation chromatography (GPC) under the following conditions: mobile phase DMF + 0.05 M LiBr, column temperature 40 °C, flow rate 1.0 mL / min. -1 Calibration was performed using polystyrene (PS) standards, with an RI detector. Mn = 5.3 × 10⁻⁶ 4 g mol -1 Mw = 1.12 × 10 5 g mol -1 Ð = 2.11

[0058] FT-IR at ≈1040 cm -1 P–O–C absorption and amide C=O bimodal peaks were observed (≈1710 / 1675 cm⁻¹). -1 ) Retained; ³¹P NMR shows a single peak signal at δ 23–26 ppm.

[0059] Example 7: Fabrication and Performance Testing of Electrochromic Devices

[0060] (I) Device Design and Structure Description

[0061] This invention employs a ProDOT derivative as the electrochromic layer (coloring layer) and synthesized dicarbonyl conjugated polymers (T-1 to T-6) as the ion storage layer to construct a bilayer electrochromic device with p–n type complementary effects, comprising ITO / ProDOT (electrochromic layer) / electrolyte gel / Tx (dicarbonyl conjugated polymer ion storage layer) / ITO. The ProDOT layer undergoes oxidative coloring under a positive bias, while the Tx layer undergoes reduction doping under a negative bias, achieving a synergistic balance of electron and ion transport, thereby significantly improving the device's optical contrast and response rate.

[0062] (II) Device fabrication process

[0063] 1. Preparation of ProDOT electrochromic layer: 0.01 mol ProDOT was dissolved in acetonitrile / propylene carbonate (volume ratio 1:1) solution, and 0.1 mol LiTFSI electrolyte was added. Polymerization was carried out on ITO electrode at +1.25 V for 60 s using a potentiostatic method to form a ProDOT film with a thickness of about 150 nm. After cleaning with acetonitrile, it was vacuum dried for later use.

[0064] 2. Preparation of ion storage layers of dicarbonyl conjugated polymers (T-1 to T-6): Dissolve each polymer in NMP / IPA (volume ratio 3:1) at a concentration of 10 mg / mL. - ¹, spin-coated onto another ITO glass (1000 rpm, drying temperature 60 °C, time 2 h) to form a thin film of about 120 nm thick.

[0065] 3. Device assembly uses [EMIM][TFSI] / PMMA gel (mass ratio 8:2) as the electrolyte medium. ProDOT and Tx layers are bonded together and pre-cured at 60 °C for 30 min before being encapsulated into a symmetrical device (effective area 2cm × 2 cm).

[0066] (III) Performance Testing Methods

[0067] 1. Optical and electrochromic properties

[0068] The transmittance in the bleached state (T_bleached), the transmittance in the colored state (T_colored), and the optical modulation amplitude ΔT were measured using a UV-Vis spectrometer. 550 ;

[0069] Calculate ΔE*ab using CIE1976 color coordinates;

[0070] Coloring and bleaching times were determined using the chronoamperometry (CA) method.

[0071] Cycle 3×10 at ±1.0 V 4 The next step is to evaluate optical stability.

[0072] 2. Electrochemical and electron transport properties

[0073] Cyclic Voltmeter (CV) Test Range 1.0 to +1.0 V, scan rate 50 mV·s - ¹;

[0074] The volume capacitance C* is calculated from the integrated charge, and the carrier mobility μ is obtained by the transient current method.

[0075] 3. Environmental stability test

[0076] At 85 °C / 85%RH, UV (365 nm, 50 mW·cm) - The transmittance and electrochromic performance retention were tested under the conditions of 200 h and salt spray (5 wt% NaCl, 48 h).

[0077] (iv) Performance test results

[0078]

[0079] (V) Results Analysis

[0080] 1. Synergistic mechanism: The ProDOT layer and the Tx layer form a complementary p–n structure, separating the electron and ion transport channels, which greatly improves the response speed and energy utilization of the device.

[0081] 2. Optical and colorimetric properties: ΔT at 550 nm for samples T-3 to T-6 550 ≥ 50%, ΔE*ab ≤ 3, achieving neutral tone conversion, with visual uniformity superior to PEDOT:PSS and unmodified n-PBDF.

[0082] 3. Electrochemical and transport performance: The introduction of polar side chains significantly improves C* and μ, increasing ion transport efficiency by 1.5–2 times, and making the electrochromic charge response more stable and reversible.

[0083] 4. Stability Performance: The T-4 to T-6 samples containing fluorine, quaternary ammonium salts, and phosphate ester side chains maintained over 90% of their performance under high temperature, high humidity, and UV aging conditions, with a cycle life exceeding 3 × 10⁻⁶. 4 Second-rate.

[0084] (vi) Overall Conclusion

[0085] A bilayer complementary electrochromic system using ProDOT as the electrochromic layer and a double carbonyl conjugated polymer as the ion storage layer exhibits low driving voltage, high optical contrast, fast response, and excellent environmental stability. By controlling the carbonyl ortho-position structure and the polar substituents in the side chains, ion conductivity and electrochemical stability can be systematically improved, providing a high-performance material system for next-generation energy-saving dimming glass, smart displays, and flexible optoelectronic devices.

Claims

1. A transparent conductive material, characterized in that, The molecular formula is as follows: --- indicates a site where adjacent repeating units are connected by fusion; A is O or NR; R is selected from H, ether chain, fluorinated ether chain, phosphate ester chain or quaternary ammonium salt chain; n is an integer between 5 and 500.

2. The transparent conductive material according to claim 1, characterized in that, R is selected from the following: Where R1, R2, and R3 are independent alkyl groups; X is selected from fluorine, chlorine, bromine, iodine, or phosphate; y is an integer from 1 to 10.

3. The transparent conductive material according to claim 1, characterized in that, Selected from the following structure: 。 4. The method for preparing the transparent conductive material according to claim 1, characterized in that, The process includes the following: Specifically, the steps include the following: S1, 2,5-diamino-1,4-phenyldiboronic acid (A-1) and diethyl 2,3-dibromofumarate (A-2) were polymerized by Suzuki coupling reaction in a 1:1 molar ratio under a catalyst to obtain intermediate A-3; S2. The intermediate A-3 undergoes transesterification or ester-aminolation under strong acid catalysis to form a lactone or lactam compound A-4.

5. The preparation method according to claim 4, characterized in that, It also includes the following steps: S3. The lactam compound A-4 reacts with a halogenated compound to give the target product A-5. The reaction process is as follows: 。 6. The application of the transparent conductive material according to any one of claims 1-3 in electrochromic devices.

7. The application according to claim 6, characterized in that, The electrochromic device is a p-n type complementary electrochromic device, with ProDOT or its derivatives as the p-type electrochromic layer and the transparent conductive material as the n-type ion storage layer.

8. The application according to claim 6, characterized in that, The electrochromic device also includes a gel electrolyte, which serves as an ion-conducting medium, located between the p-type electrochromic layer and the n-type ion storage layer.

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