Polymer film with metallic charge transport and preparation method thereof

Abstract

The invention belongs to the technical field of conductive polymers, and discloses a polymer film with metallic charge transport and a preparation method thereof. The polymer film with the metallic charge transport function is obtained by preparing PBFDO into a film; the film forming mode is spin coating, blade coating or dispensing rapid drying; during dispensing, the temperature is greater than or equal to 155 DEG C. The invention also discloses a preparation method of the film. According to the invention, the n-type conductive polymer film for metallic charge transport is successfully obtained, and the film provided by the invention can show metallic charge transport in a temperature interval of 20K to 300K. The method is simple in process and low in cost.

Description

Technical Field

[0001] The invention belongs to the field of functional polymer materials, and in particular relates to a film with metallic charge transport and a preparation method thereof. Background Art

[0002] Conductive polymers have been widely developed because they combine the conductivity of metals with the mechanical flexibility and processing properties of plastics. These materials provide key support for cutting-edge fields such as flexible electronics, wearable devices, sensors, and energy storage systems. Through molecular design, improved synthesis methods, and optimized processing technology, researchers have increased the conductivity of conductive polymers from about 10 to 10. -3 S cm -1 Increased to 10 4 S cm -1 .

[0003] However, compared to traditional metal materials, the key challenge facing conductive polymers is to achieve true metallic charge transport behavior. Currently, most conductive polymers only exhibit metal-like heat capacity, magnetic susceptibility, thermoelectric potential, and light reflection properties, but it is difficult to achieve true metallic behavior with increasing conductivity as the temperature decreases. Although a few materials such as p-type doped polyaniline (PANI) and poly (2,5-di(3-alkylthiophen-2-yl)thiophene) (PBTTT) can achieve positive temperature coefficient resistance characteristics under specific conditions, achieving metallic charge transport in n-type conductive polymers remains a significant challenge. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the prior art, the present invention aims to provide an n-type polymer film with metallic charge transport and a preparation method thereof.

[0005] The present invention is achieved through the following technical solutions:

[0006] A polymer film with metallic charge transport is prepared from PBFDO (polybenzofurandione) into a film; the film forming method is spin coating, blade coating or drop coating and rapid drying.

[0007] The structure of PBFDO:

[0008]

[0009] The spin coating speed is 1000-9000 rpm, preferably 4000-8000 rpm, more preferably 5000-7000 rpm; the drying temperature after spin coating is 40-160° C., preferably 80-140° C., more preferably 110-130° C.

[0010] The spin coating drying time is 0.5 to 1.5 hours.

[0011] The speed of blade coating is 50 - 200 mm / min, and the temperature during blade coating is 100 - 200 °C. After blade coating, it is left standing for drying for 10 min - 1.5 h.

[0012] During drop coating, the temperature is 155 - 180 °C, and the time for continued drying after drop coating is 0.5 - 1.5 h. The dropping speed during drop coating is 1 - 10 μL / min.

[0013] PBFDO (polyphenylene benzobisoxazole dione) is first made into a solution, and the concentration of the solution is 5 - 15 mg / ml; the solvent is a high-polarity solvent such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, etc.

[0014] The preparation method of the polymer film with metallic charge transport includes the following steps: PBFDO (polyphenylene benzobisoxazole dione) is made into a solution, and then it is formed into a film by means of oriented film formation or rapid drying by drop coating to obtain a polymer film with metallic charge transport. Oriented film formation includes spin coating and blade coating.

[0015] The film of the present invention is deposited on a substrate with electrodes. The distance between the voltage terminal electrodes is 1 - 100 μm, preferably 1 - 10 μm.

[0016] Although there are various ways to form a film of PBFDO solution, including methods such as spin coating, blade coating, and drop coating, the drop-coated film dries slowly (drying at 40 °C - 120 °C, the temperature during drop coating and the drying temperature), and it cannot exhibit metallicity, while the spin-coated, blade-coated films and the rapidly dried drop-coated films (155 - 180 °C, the temperature during drop coating and the drying temperature) can all exhibit metallic charge transport. And the spin-coated film shows the best metallicity (the smaller the ratio of the low-temperature resistance to the resistance at 300K, the better the metallicity performance).

[0017] Compared with the prior art, the present invention has the following beneficial effects and advantages: The present invention successfully obtains an n-type conductive polymer film with metallic charge transport. The film of the present invention can exhibit metallic charge transport in the temperature range of 20K to 300K, which is the only example in n-type conductive polymers. The method of the present invention has a simple process and low cost. Description of the Drawings

[0018] Figure 1 Appears for the change of the resistance ratio of the films prepared in Examples 1 - 3 with temperature; spin coating corresponds to Example 1, blade coating corresponds to Example 2, and rapidly dried drop coating corresponds to Example 3;

[0019] Figure 2 Curves of the change of the resistance ratio with temperature for the films prepared in Example 1 and Comparative Example 1;

[0020] Figure 3 The curve graph of the resistance ratio of the film obtained by changing the drying temperature in Example 1 and keeping other conditions the same as those in Example 1 versus temperature;

[0021] Figure 4 The curve graph of the change of the resistance ratio of the film prepared by changing the spin coating speed in Example 1 and keeping other conditions the same as those in Example 1 with respect to temperature. Detailed implementation manners

[0022] The present invention will be further described in detail below in conjunction with the embodiments and the drawings. However, the implementation manners and protection scope of the present invention are not limited thereto.

[0023] Example 1

[0024] The polybenzodifurandione (PBFDO) of this example has the following structure:

[0025]

[0026] The substrate (such as a silicon wafer) with electrodes pre-evaporated (the distance between the voltage terminal electrodes is 2 μm) is successively ultrasonically treated with deionized water, ethanol, dichloromethane, and isopropanol for 30 min, and then placed in an oven at 80 °C and left to stand for 6 h to dry for later use. Then, a plasma machine is used to perform plasma cleaning on the substrate to improve wettability.

[0027] In an N2 glove box, the substrate is fixed on a spin coater by negative pressure, 100 μL of PBFDO solution (concentration: 10 mg / ml, solvent: dimethyl sulfoxide) is dropped on the substrate, and spin coating is carried out (the spin coating speed is 6000 rpm, and the spin coating time is 30 s). After spin coating, the substrate with the material is transferred to a heating table at 120 °C and heated for 1 hour to obtain a film. This film exhibits metallic charge transport.

[0028] Example 2

[0029] The polybenzodifurandione (PBFDO) of this example has the following structure:

[0030]

[0031] The substrate with electrodes pre-evaporated (the distance between the voltage terminal electrodes is 2 μm) is successively ultrasonically treated with deionized water, ethanol, dichloromethane, and isopropanol for 30 min, and then placed in an oven at 80 °C and left to stand for 6 h to dry for later use. Then, a plasma machine is used to perform plasma cleaning on the substrate to improve wettability.

[0032] In an atmospheric environment, the substrate is fixed on a doctor blade plate using negative pressure. The temperature of the plate is 150 °C. 200 μL of a PBFDO solution (concentration 10 mg / ml, solvent dimethyl sulfoxide) is dropped onto the substrate, and then doctor blading is performed. After doctor blading, it is left to stand and dry (for 1 h). Metallic charge transport can then be exhibited.

[0033] Example 3

[0034] The polybenzodifurandione (PBFDO) of this example has the following structure:

[0035]

[0036] The substrate with electrodes pre-evaporated (distance between voltage terminal electrodes 2 μm) is successively ultrasonically treated with deionized water, ethanol, dichloromethane, and isopropanol for 30 min, and then placed in an oven at 80 °C and left to stand for 6 h to dry for later use. Then, using a plasma machine, the substrate is subjected to plasma cleaning to improve wettability.

[0037] In an N2 glove box, the substrate is placed on a heating stage at 160 °C, and 100 μL of the synthesized PBFDO solution (concentration 10 mg / ml) is dropped onto the substrate (finished dropping within 30 s), and then heated and dried for 1 hour to obtain a film. This film exhibits metallic charge transport.

[0038] Comparative Example 1

[0039] The polybenzodifurandione (PBFDO) of this example has the following structure:

[0040]

[0041] The substrate with electrodes pre-evaporated (distance between voltage terminal electrodes 2 μm) is successively ultrasonically treated with deionized water, ethanol, dichloromethane, and isopropanol for 30 min, and then placed in an oven at 80 °C and left to stand for 6 h to dry for later use. Then, using a plasma machine, the substrate is subjected to plasma cleaning to improve wettability.

[0042] In an N2 glove box, the substrate is placed on a heating stage at 80 °C, and 100 μL of the synthesized PBFDO solution is dropped onto the substrate, and then heated and dried for 1 hour to obtain a film. This film cannot exhibit metallic charge transport.

[0043] Figure 1 The resistance ratio of the films prepared in Examples 1 to 3 changes with temperature; spin coating corresponds to Example 1, doctor blading corresponds to Example 2, and drop coating with rapid drying corresponds to Example 3;

[0044] Figure 2 Curves of the resistance ratio of the films prepared in Example 1 and Comparative Example 1 changing with temperature;

[0045] Figure 3 The curve graph of the resistance ratio of the film obtained by changing the drying temperature in Example 1 and keeping other conditions the same as those in Example 1 against temperature;

[0046] Figure 4 The curve graph of the resistance ratio of the film prepared by changing the spin coating speed in Example 1 and keeping other conditions the same as those in Example 1 against temperature. Spin-4000, Spin-6000, and Spin-8000 represent the spin coating speeds.

[0047] Through theoretical calculation, it is found that in the ground state structure of PBFDO, the energy difference between the aromatic structure and the quinone structure is very small (ΔE = -15 meV), and it has a nearly degenerate ground state structure.

[0048] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A polymer film with metallic charge transport, characterized in that: It is obtained by preparing PBFDO into a film; the film-forming method is spin coating, blade coating or drop coating followed by rapid drying; The structure of PBFDO: When drop coating, the temperature ≥ 155 °C.

2. The polymer film with metallic charge transport according to claim 1, characterized in that: The rotation speed of the spin coating is 1000 - 9000 rpm; the drying temperature after spin coating is 40 - 160 °C.

3. The polymer film with metallic charge transport according to claim 2, wherein: The rotation speed of the spin coating is 4000 - 8000 rpm; the drying temperature after spin coating is 80 - 140 °C.

4. The polymer film with metallic charge transport according to claim 3, characterized in that: The rotation speed of the spin coating is 5000 - 7000 rpm; the drying temperature after spin coating is 110 - 130 °C.

5. The polymer thin film with metallic charge transport according to claim 1, wherein: The drying time of the spin coating is 0.5 - 1.5 h; The speed of the blade coating is 50 - 200 mm / min, and the temperature during blade coating is 100 - 200 °C; When drop coating, the temperature is 155 - 180 °C, and the continued drying time after drop coating is 0.5 - 1.5 h; The dropping speed during drop coating is 1 - 10 μL / min.

6. The preparation method of the polymer film with metallic charge transport according to any one of claims 1 to 5, characterized in that: It includes the following steps: Prepare PBFDO into a solution, and then form a film by the method of oriented film formation or drop coating followed by rapid drying to obtain a polymer film with metallic charge transport.

7. The preparation method of the polymer film with metallic charge transport according to claim 6, characterized in that: The oriented film formation includes spin coating and blade coating.

8. The polymer film with metallic charge transport according to claim 6, characterized in that: PBFDO is first prepared into a solution, and the concentration of the solution is 5 - 15 mg / ml; the solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

9. Use of the polymer film with metallic charge transport according to any one of claims 1 to 5, characterized in that: The polymer film with metallic charge transport is used for constructing a physical conduction mechanism model and preparing flexible wires.

Images