A method for preparing a high-conductivity PEDOT:PSS polymer micrometer-thick film based on a low-boiling-point polar solvent at room temperature and applications thereof

Abstract

The application discloses a room temperature large-area preparation method of a PEDOT:PSS high-conductivity polymer micrometer-thickness film based on a low-boiling-point polar solvent and application thereof, and belongs to the field of flexible electronic device materials. The application aims at solving the technical problems that the existing preparation of a conductive polymer thick film is limited by a dense network to solvent permeation, and excessively depends on high-temperature annealing and strong acid treatment. The method comprises the following steps: 1, preparation of a precursor solution; 2, film formation at room temperature; and 3, ethanol immersion and reconfiguration post-treatment. The application is used for preparing a flexible thermoelectric device or a flexible electromagnetic interference shielding device.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronic device materials. Background Technology

[0002] Conductive polymers hold significant application potential in flexible electronic devices, such as body heat harvesters and electromagnetic shielding devices. Among them, poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS) is widely used in flexible electronic devices, thermoelectric devices, and electromagnetic shielding materials due to its excellent conductivity, flexibility, and solution processability. However, existing traditional strategies for improving the conductivity of PEDOT:PSS heavily rely on high-boiling-point polar solvents, ionic liquids, or strong acid post-treatment. These methods often require additional thermal annealing processes or inevitably introduce acidic residues, thus increasing energy consumption and causing environmental pollution. Low-boiling-point polar solvents are generally not considered effective dopants in the literature and have a limited effect on improving conductivity, thus requiring less research.

[0003] Furthermore, although solution-based film-forming techniques such as spraying or inkjet printing are widely used for large-scale manufacturing, the thickness of the films they produce is mostly limited to the nanometer scale, posing a significant bottleneck for large-area practical applications. In contrast, micrometer-thick films offer significant advantages in mechanical robustness, high output power, and maintenance of temperature gradients, making them more attractive for the development of practical devices. However, existing conductivity enhancement strategies often fail as film thickness increases, mainly because the dense polymer network in thick films severely restricts the effective penetration of solvents. Therefore, there is an urgent need to develop a green and scalable synthesis method for achieving micrometer-thick conductive polymer films at room temperature. Summary of the Invention

[0004] This invention aims to address the technical problems in existing conductive polymer thick film preparation, such as dense networks limiting solvent penetration and excessive reliance on high-temperature annealing and strong acid treatment. It provides a room-temperature, large-area preparation method for micron-sized thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvents, and its applications.

[0005] A room-temperature, large-area method for preparing micron-sized thick films of PEDOT:PSS high-conductivity polymer based on a low-boiling-point polar solvent is disclosed, comprising the following steps:

[0006] I. Preparation of precursor solution:

[0007] Add a low-boiling-point polar solvent to the PEDOT:PSS aqueous solution and mix evenly. Then filter to remove impurities to obtain a doped precursor solution.

[0008] The boiling point of the low-boiling-point polar solvent is <100℃;

[0009] II. Film formation at room temperature:

[0010] The doped precursor solution was cast into a mold and then dried naturally at room temperature to obtain a PEDOT:PSS precursor thick film.

[0011] III. Post-treatment after ethanol immersion reconstruction:

[0012] The PEDOT:PSS precursor thick film was immersed in ethanol solvent for post-treatment, and then naturally dried at room temperature to obtain a micron-scale thick film of PEDOT:PSS high electrical conductivity polymer.

[0013] Applications of PEDOT:PSS high conductivity polymer micron-scale thick films: It is used to prepare flexible thermoelectric devices or flexible electromagnetic interference shielding devices.

[0014] The beneficial effects of this invention are:

[0015] 1. Green and low-carbon, simple process: The method of this invention is carried out at room temperature throughout, eliminating the complicated processing steps and high-temperature heat annealing process in traditional preparation methods, and does not require the use of toxic and harmful solvents or strong acids, which has extremely significant energy-saving and environmental protection advantages.

[0016] 2. Overcoming the limitation of balancing thickness and conductivity: Low-boiling-point polar solvents do not directly increase conductivity, but rather act as a key modulator to adjust the precursor polymer network, promoting the deep penetration of subsequent ethanol and the reconstruction of the film. The 8-inch wafer-level film prepared using this method still exhibits a high conductivity of 852.21 S / cm even at a thickness of 20.19 μm. This represents an excellent synergistic combination of conductivity and thickness achievable in micron-scale PEDOT:PSS films without the use of hazardous solvents.

[0017] 3. It endows the device with excellent flexibility and functional output performance:

[0018] In thermoelectric energy harvesting: the flexible thermoelectric generator assembled using this thick film can provide an extremely high output power of 411.89 nW at a temperature difference of 48 K, far exceeding the previously reported similar devices based on PEDOT:PSS.

[0019] In electromagnetic shielding applications: The film has a densely reconstructed conductive network, which enables it to achieve a thickness-normalized electromagnetic interference shielding effectiveness of 2231.72 dB / mm, a figure that represents an extremely high record in the field of conductive polymers. Attached Figure Description

[0020] Figure 1 This is a photograph of the micron-sized thick film of PEDOT:PSS high conductivity polymer prepared in step three of Example 1.

[0021] Figure 2 This is a SEM image of the cross-section of the PEDOT:PSS precursor thick film prepared in step two of Example 1.

[0022] Figure 3 This is a SEM image of the cross-section of the micron-scale thick film of PEDOT:PSS high conductivity polymer prepared in step three of Example 1;

[0023] Figure 4 Raman spectra of the PEDOT:PSS precursor thick films prepared in Example 1, Comparative Experiment 1, and Step 2 of Experiment 2 are shown. EAC represents Example 1, None represents Comparative Experiment 1, and DMSO represents Comparative Experiment 2.

[0024] Figure 5 This describes the conductivity enhancement mechanism of the PEDOT:PSS high conductivity polymer micron-scale thick film prepared in step three of Example 1.

[0025] Figure 6 The images show the cross-sections of micron-scale thick films of PEDOT:PSS high-conductivity polymers prepared in Example 1, Comparative Experiment 1, and Step 3. None-EtOH represents Comparative Experiment 1, EG-EtOH represents Comparative Experiment 3, and EAC-EtOH represents Example 1.

[0026] Figure 7 The diagram shows the conductivity of the PEDOT:PSS precursor thick film prepared in step two of Examples 1, Comparative Experiments 1 and 2, and the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three. In the diagram, None represents the PEDOT:PSS precursor thick film prepared in step two of Comparative Experiment 1, DMSO-doped represents the PEDOT:PSS precursor thick film prepared in step two of Comparative Experiment 2, EAC-doped represents the PEDOT:PSS precursor thick film prepared in step two of Example 1, None-EtOH represents the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three of Comparative Experiment 1, DMSO-EtOH represents the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three of Comparative Experiment 2, and EAC-EtOH represents the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three of Example 1.

[0027] Figure 8 This is a schematic diagram of the flexible thermoelectric generator in Example 2;

[0028] Figure 9 This is a schematic diagram of the output performance of the flexible thermoelectric generator prepared in Example 2;

[0029] Figure 10 The image shows an actual optical picture and a schematic diagram of the output performance of the flexible thermoelectric generator prepared in Example 2 worn on the skin of a human wrist.

[0030] Figure 11 The graph shows a comparison of the electromagnetic interference (EMI) performance of the PEDOT:PSS high conductivity polymer micron-scale thick film prepared in Example 1 with that of typical electromagnetic shielding materials prepared by existing technologies. 1 to 6 are typical electromagnetic shielding materials prepared by existing technologies.

[0031] Figure 12 This is a schematic diagram illustrating the practical application and electric field shielding effect of the PEDOT:PSS high conductivity polymer micron-scale thick film prepared in Example 1, which demonstrates electromagnetic interference (EMI). Detailed Implementation

[0032] Specific Implementation Method 1: This implementation method is a room-temperature, large-area preparation method for micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvents. It is carried out according to the following steps:

[0033] I. Preparation of precursor solution:

[0034] Add a low-boiling-point polar solvent to the PEDOT:PSS aqueous solution and mix evenly. Then filter to remove impurities to obtain a doped precursor solution.

[0035] The boiling point of the low-boiling-point polar solvent is <100℃;

[0036] II. Film formation at room temperature:

[0037] The doped precursor solution was cast into a mold and then dried naturally at room temperature to obtain a PEDOT:PSS precursor thick film.

[0038] III. Post-treatment after ethanol immersion reconstruction:

[0039] The PEDOT:PSS precursor thick film was immersed in ethanol solvent for post-treatment, and then naturally dried at room temperature to obtain a micron-scale thick film of PEDOT:PSS high electrical conductivity polymer.

[0040] In this specific embodiment, step two, using a low-boiling-point polar solvent (boiling point < 100°C), can induce the formation of a polymer network morphology with expanded internal structures, thereby significantly improving the accessibility of subsequent solvents, i.e., forming a relatively loose, solvent-accessible precursor structure. Thanks to the expanded structure of the precursor, ethanol in step three can achieve deep penetration, prompting structural reconstruction of the film across its entire thickness range and the formation of continuous conductive network pathways, ultimately resulting in a micron-scale thick film of the PEDOT:PSS polymer with high electrical conductivity.

[0041] The beneficial effects of this embodiment are:

[0042] 1. Green and low-carbon, simple process: The method of this embodiment is carried out at room temperature throughout, eliminating the complicated processing steps and high-temperature heat annealing process in traditional preparation methods, and does not require the use of toxic and harmful solvents or strong acids, which has extremely significant energy-saving and environmental protection advantages.

[0043] 2. Overcoming the limitation of balancing thickness and conductivity: Low-boiling-point polar solvents do not directly increase conductivity, but rather act as a key modulator to adjust the precursor polymer network, promoting the deep penetration of subsequent ethanol and the reconstruction of the film. The 8-inch wafer-level film prepared using this method still exhibits a high conductivity of 852.21 S / cm even at a thickness of 20.19 μm. This represents an excellent synergistic combination of conductivity and thickness achievable in micron-scale PEDOT:PSS films without the use of hazardous solvents.

[0044] 3. It endows the device with excellent flexibility and functional output performance:

[0045] In thermoelectric energy harvesting: the flexible thermoelectric generator assembled using this thick film can provide an extremely high output power of 411.89 nW at a temperature difference of 48 K, far exceeding the previously reported similar devices based on PEDOT:PSS.

[0046] In electromagnetic shielding applications: The film has a densely reconstructed conductive network, which enables it to achieve a thickness-normalized electromagnetic interference shielding effectiveness of 2231.72 dB / mm, a figure that represents an extremely high record in the field of conductive polymers.

[0047] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the concentration of PEDOT:PSS in the PEDOT:PSS aqueous solution described in step one is 1.0wt%~1.3wt%, and the mass ratio of PSS to PEDOT is (2~3):1. Everything else is the same as in Specific Implementation Method One.

[0048] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the amount of low-boiling-point polar solvent added in step one is 2wt% to 10wt% of the mass of the PEDOT:PSS aqueous solution. Everything else is the same as in Specific Implementation Method One or Two.

[0049] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the low-boiling-point polar solvent mentioned in step one is tetrahydrofuran, ethyl acetate, isopropanol, dichloromethane, acetonitrile, or methanol. Everything else is the same as in Specific Implementation Methods One to Three.

[0050] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: the uniform mixing described in step one is specifically carried out at a stirring speed of 200 rpm to 600 rpm for 10 min to 60 min; the filtration to remove impurities described in step one is specifically carried out using a 0.22 μm to 0.45 μm syringe-type filter membrane. Everything else is the same as in Specific Implementation Methods One to Four.

[0051] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the diameter of the PEDOT:PSS precursor thick film described in step two is 2 inches to 16 inches, and the thickness is 30 μm to 60 μm. Everything else is the same as in Specific Implementation Methods One to Five.

[0052] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the post-treatment described in step three is specifically performed at room temperature, involving immersion for 10 to 60 minutes. The rest is the same as Specific Implementation Methods One to Six.

[0053] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the natural drying at room temperature in steps Two and Three is performed for 24 to 48 hours at room temperature. Everything else is the same as in Specific Implementation Methods One to Seven.

[0054] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the PEDOT:PSS high-conductivity polymer micron-sized thick film described in step three has a diameter of 2 inches to 16 inches, a thickness of 20 μm to 50 μm, and a conductivity of 852.21 S / cm or higher. Everything else is the same as in Specific Implementation Methods One to Eight.

[0055] Specific Implementation Method 10: This implementation method is the application of PEDOT:PSS high conductivity polymer micron-scale thick film, which is used to prepare flexible thermoelectric devices or flexible electromagnetic interference shielding devices.

[0056] The beneficial effects of the present invention are verified using the following embodiments:

[0057] Example 1:

[0058] A room-temperature, large-area method for preparing micron-sized thick films of PEDOT:PSS high-conductivity polymer based on a low-boiling-point polar solvent is disclosed, comprising the following steps:

[0059] I. Preparation of precursor solution:

[0060] Under a stirring speed of 300 rpm, a low-boiling-point polar solvent was added to the PEDOT:PSS aqueous solution and mixed for 30 min. Then, impurities were removed by filtration using a 0.45 μm syringe-type filter membrane to obtain the doped precursor solution.

[0061] The low-boiling-point polar solvent is ethyl acetate (EAC).

[0062] The PEDOT:PSS aqueous solution is of type Clevios PH 1000, the concentration of PEDOT:PSS is 1.3wt%, and the mass ratio of PSS to PEDOT is 2.5:1.

[0063] The amount of the low-boiling-point polar solvent added is 4 wt% of the mass of the PEDOT:PSS aqueous solution;

[0064] II. Film formation at room temperature:

[0065] The doped precursor solution was cast into an 8-inch polytetrafluoroethylene disk mold and then naturally dried at room temperature for 24 hours to obtain a PEDOT:PSS precursor thick film.

[0066] The PEDOT:PSS precursor thick film has a diameter of 8 inches and a thickness of 30.96 μm.

[0067] III. Post-treatment after ethanol immersion reconstruction:

[0068] At room temperature, the PEDOT:PSS precursor thick film was immersed in ethanol solvent for 30 min and then dried naturally at room temperature for 24 h to obtain a micron-scale thick film of PEDOT:PSS high conductivity polymer, named EAC-EtOH.

[0069] The PEDOT:PSS high conductivity polymer micron-scale thick film prepared in Example 1 has a diameter of 8 inches, a thickness of 20.19 μm, and a conductivity of 852.21 S / cm.

[0070] Comparative Experiment 1: This comparative experiment differs from Example 1 in that the addition of a low-boiling-point polar solvent is omitted in step one. Everything else is the same as in Example 1.

[0071] Comparative Experiment 2: This comparative experiment differs from Example 1 in that the low-boiling-point polar solvent in step one is replaced with a high-boiling-point polar solvent, namely dimethyl sulfoxide (DMSO). Everything else is the same as in Example 1.

[0072] Comparative Experiment 3: This comparative experiment differs from Example 1 in that the low-boiling-point polar solvent in step one is replaced with a high-boiling-point polar solvent, namely ethylene glycol (EG). Everything else is the same as in Example 1.

[0073] Figure 1 The image shows a physical picture of the PEDOT:PSS high conductivity polymer micron-scale thick film prepared in step three of Example 1. As can be seen from the figure, an ultra-large area 8-inch wafer-level polymer thick film can be prepared in one go using a mold, and the structure is complete.

[0074] Figure 2 The image shows a cross-sectional SEM image of the PEDOT:PSS precursor thick film prepared in step two of Example 1. As can be seen from the image, the prepared PEDOT:PSS precursor thick film maintains the integrity of an 8-inch large area while achieving a thickness of 30.96 μm.

[0075] Figure 3 The image shows a cross-section of the PEDOT:PSS high conductivity polymer micron-scale thick film prepared in step three of Example 1. As can be seen from the image, the prepared PEDOT:PSS high conductivity polymer micron-scale thick film maintains the integrity of an 8-inch large area while achieving a thickness of 20.19 μm.

[0076] Figure 4 The images show the Raman spectra of the PEDOT:PSS precursor thick films prepared in Example 1, Comparative Experiment 1, and Step 2 of Experiment 2. EAC represents Example 1, None represents Comparative Experiment 1, and DMSO represents Comparative Experiment 2. As can be seen from the figures, the doping of low-boiling-point polar solvents causes the C=C bond peak in PEDOT to shift to the right, the thiophene unit to transform from a kun-type to a benzene-type structure, and the molecular chain configuration to simultaneously transform to a coiled manner. The precursor structure transforms from a dense structure to an expanded structure, which is a polymer morphology with an expanded internal structure.

[0077] Figure 5 This describes the conductivity enhancement mechanism of the PEDOT:PSS high-conductivity polymer micron-scale thick film prepared in step three of Example 1. In traditional preparation methods, the dense molecular chain stacking mode leads to limited penetration of post-processing solvents. However, doping with low-boiling-point polar solvents can induce a transformation of the structure from dense to expanded, making it easier for post-processing solvents to penetrate. This results in full-thickness polymer chain reconstruction, forming a highly conductive pathway with excellent inter-chain continuity, and promoting a significant increase in conductivity.

[0078] Figure 6 The figures show AFM images of the cross-sections of the micron-scale thick films of the PEDOT:PSS high-conductivity polymer prepared in Example 1, Comparative Experiment 1, and Step 3. None-EtOH represents Comparative Experiment 1, EG-EtOH represents Comparative Experiment 3, and EAC-EtOH represents Example 1. As can be seen from the figures, compared to other samples, the flexible thick film sample EAC-EtOH exhibits larger highly conductive crystalline domains, forming more interconnected conductive pathways.

[0079] Figure 7 The diagram shows the conductivity of the PEDOT:PSS precursor thick film prepared in step two of Examples 1, Comparative Experiments 1 and 2, and the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three. In the diagram, None represents the PEDOT:PSS precursor thick film prepared in step two of Comparative Experiment 1, DMSO-doped represents the PEDOT:PSS precursor thick film prepared in step two of Comparative Experiment 2, EAC-doped represents the PEDOT:PSS precursor thick film prepared in step two of Example 1, None-EtOH represents the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three of Comparative Experiment 1, DMSO-EtOH represents the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three of Comparative Experiment 2, and EAC-EtOH represents the PEDOT:PSS high conductivity polymer micron-sized thick film prepared in step three of Example 1. The EAC-doped PEDOT:PSS precursor thick film did not show a significant increase in conductivity. However, after ethanol post-treatment, the conductivity increased beyond that of the undoped and DMSO-doped samples.

[0080] Example 2, combined with Figure 8 Detailed Explanation: A flexible thermoelectric generator (FTEG) was fabricated using a micron-scale thick film of the PEDOT:PSS high-conductivity polymer prepared in Example 1.

[0081] (1) The micron-sized thick film of PEDOT:PSS high conductivity polymer prepared in Example 1 was cut into 5 p-type PEDOT:PSS independent legs, and the size of a single leg was set to 24mm×6mm×20.19μm;

[0082] (2) Five p-type PEDOT:PSS independent support legs are attached parallel to each other on a polyimide (PI) insulating flexible substrate with a safety spacing of 5 mm;

[0083] (3) Use commercial silver paste to connect multiple thin copper wires to the two ends of each leg, so that the five legs are connected in series electrically and in parallel in thermal conduction. Then use copper foil tape to fix the ends of the legs to the PI substrate and let it stand at room temperature for 24 hours until the silver paste is completely cured to form a reliable contact, thus obtaining a flexible thermoelectric generator (FTEG).

[0084] Figure 9 The figure shows the output performance of the flexible thermoelectric generator prepared in Example 2. As can be seen from the figure, the flexible thermoelectric generator prepared in Example 2 exhibited excellent energy harvesting capability in the test. Under the condition of establishing a temperature difference of 48K between the heating end and the cold end, the maximum output power reached 411.89nW.

[0085] Figure 10The image shows an actual optical picture and output performance diagram of the flexible thermoelectric generator prepared in Example 2 worn on the skin of a human wrist. As can be seen from the figure, under the condition that the human skin is the hot end and the atmosphere is the cold end, the device generates a voltage of 0.84mV.

[0086] Example 3: The micron-sized thick film of PEDOT:PSS high conductivity polymer prepared in Example 1 forms a highly continuous conductive PEDOT-rich region due to ethanol infiltration and reconstruction, which can be directly used as an electromagnetic shielding protective layer for wearable electronic products.

[0087] Figure 11 The figure shows a comparison of the electromagnetic interference (EMI) performance of the PEDOT:PSS high-conductivity polymer micron-scale thick film prepared in Example 1 with that of typical electromagnetic shielding materials prepared by existing technologies. Figures 1 to 6 represent typical electromagnetic shielding materials prepared by existing technologies. As can be seen from the figure, the normalized ratio shielding effectiveness (EMI SE / t) of the PEDOT:PSS high-conductivity polymer micron-scale thick film prepared in Example 1 is as high as 2231.72 dB / mm, which fully demonstrates that this method achieves extremely high-efficiency electromagnetic radiation protection through the synergistic optimization of conductivity and thickness.

[0088] Figure 11 The performance data of typical electromagnetic shielding materials prepared by existing technologies in China were obtained from the following literature:

[0089] Figure 11 Data for intermediate sample 1 are based on: Liu, J., McKeon, L., Garcia, J., Pinilla, S., Barwich, S., Möbius, M., Stamenov, P., Coleman, JN, and Nicolosi, V. (2022). Additive Manufacturing of Ti3C2-MXene-Functionalized ConductivePolymer Hydrogels for Electromagnetic-Interference Shielding. Adv. Mater. 34,2106253. https: / / doi.org / 10.1002 / adma.202106253;

[0090] Figure 11Data for sample 2 are based on: Shahzad, F., Alhabeb, M., Hatter, CB, Anasori, B., Man Hong, S., Koo, CM, and Gogotsi, Y. (2016). Electromagnetic interference shielding with 2D transition metal carbides (MXenes). Science 353, 1137-1140. https: / / doi.org / 10.1126 / science.aag2421;

[0091] Figure 11 Data basis for medium sample 3: Cao, W.-T., Chen, F.-F., Zhu, Y.-J., Zhang, Y.-G., Jiang, Y.-Y., Ma, M.-G., and Chen, F. (2018). Binary Strengthening and Toughening of MXene / Cellulose Nanofiber Composite Paper with Nacre-InspiredStructure and Superior Electromagnetic Interference Shielding Properties. ACSNano 12, 4583-4593. https: / / doi.org / 10.1021 / acsnano.8b00997;

[0092] Figure 11 Medium sample 4 data based on: Saboor, A., Khalid, SM, Jan, R., Khan, AN, Zia, T., Farooq, MU, Afridi, S., Sadiq, M., and Arif, M. (2019). PS / PANI / MoS2 Hybrid Polymer Composites with High Dielectric Behavior and ElectricalConductivity for EMI Shielding Effectiveness. Materials 12, 2690. https: / / doi.org / 10.3390 / ma12172690;

[0093] Figure 11 Medium sample 5 data based on: Bhaskara Rao, BV, Yadav, P., Aepuru, R., Panda, HS, Ogale, S., and Kale, SN (2015). Single-layer graphene-assembled 3Dporous carbon composites with PVA and Fe3O4 nano-fillers: an interface-mediated superior dielectric and EMI shielding performance. Phys. Chem. Chem.Phys. 17, 18353-18363. https: / / doi.org / 10.1039 / C5CP02476E;

[0094] Figure 11 Data for intermediate sample 6 are based on: Nguyen, V.-T., Min, BK, Yi, Y., Kim, SJ, and Choi, C.-G. (2020). MXene(Ti3C2T) X ) / graphene / PDMS composites for multifunctional broadband electromagnetic interference shielding skins. Chem.Eng. J. 393, 124608. https: / / doi.org / 10.1016 / j.cej.2020.124608.

[0095] Figure 12 This diagram illustrates the practical application and electric field shielding effect of the PEDOT:PSS high-conductivity polymer micron-scale thick film prepared in Example 1, demonstrating its electromagnetic interference (EMI) performance. In a field test in the X-band (8.2GHz~12.4GHz frequency range), a smartphone supporting reverse wireless charging was used to charge a smartwatch. As shown in the figure, the electromagnetic field radiation level at the charging interface was originally as high as 180V / m. When the thick film (EAC-EtOH film) prepared in Example 1 was used to cover the wireless charging device, the charging connection to the watch was instantly severed, and the radiation leakage level monitored by the measuring instrument dropped sharply to below 15V / m.

Claims

1. A method for room-temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvents, characterized in that... It is done in the following steps: I. Preparation of precursor solution: Add a low-boiling-point polar solvent to the PEDOT:PSS aqueous solution and mix evenly. Then filter to remove impurities to obtain a doped precursor solution. The boiling point of the low-boiling-point polar solvent is <100℃; II. Film formation at room temperature: The doped precursor solution was cast into a mold and then dried naturally at room temperature to obtain a PEDOT:PSS precursor thick film. III. Post-treatment after ethanol immersion reconstruction: The PEDOT:PSS precursor thick film was immersed in ethanol solvent for post-treatment, and then naturally dried at room temperature to obtain a micron-scale thick film of PEDOT:PSS high electrical conductivity polymer.

2. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... The concentration of PEDOT:PSS in the PEDOT:PSS aqueous solution mentioned in step one is 1.0wt%~1.3wt%, and the mass ratio of PSS to PEDOT is (2~3):

1.

3. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... The amount of low-boiling-point polar solvent added in step one is 2wt% to 10wt% of the mass of the PEDOT:PSS aqueous solution.

4. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... The low-boiling-point polar solvent mentioned in step one is tetrahydrofuran, ethyl acetate, isopropanol, dichloromethane, acetonitrile, or methanol.

5. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... The uniform mixing mentioned in step one specifically refers to mixing for 10 to 60 minutes at a stirring speed of 200 rpm to 600 rpm; the filtration to remove impurities mentioned in step one specifically refers to filtration using a syringe-type filter membrane with a diameter of 0.22 μm to 0.45 μm.

6. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... The PEDOT:PSS precursor thick film mentioned in step two has a diameter of 2 inches to 16 inches and a thickness of 30 μm to 60 μm.

7. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... The post-treatment described in step three specifically involves immersion treatment at room temperature for 10 to 60 minutes.

8. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... In both steps two and three, the natural drying at room temperature is carried out for 24 to 48 hours.

9. The method for room temperature large-area preparation of micron-scale thick films of PEDOT:PSS high-conductivity polymer based on low-boiling-point polar solvent according to claim 1, characterized in that... The PEDOT:PSS high conductivity polymer micron-scale thick film mentioned in step three has a diameter of 2 inches to 16 inches, a thickness of 20 μm to 50 μm, and a conductivity of 852.21 S / cm or higher.

10. The application of the micron-scale thick film of PEDOT:PSS high conductivity polymer prepared according to claim 1, characterized in that... It is used to manufacture flexible thermoelectric devices or flexible electromagnetic interference shielding devices.

Images