阅读说明：本技术 一种用于增强钙钛矿结晶度安全的方法 (Method for enhancing safety of perovskite crystallinity ) 是由 张正国 刘海 柯义虎 于 2021-06-17 设计创作，主要内容包括：本发明公开了一种用于增强钙钛矿结晶度安全的方法,包括：取等摩尔质量的干燥的钛酸钡粉体与N,N-二甲基乙酰胺,将钛酸钡粉体加入N,N-二甲基乙酰胺(DMAC)中超声、搅拌一定时间,直至呈均匀牛奶状悬浊液；将悬浊液加入取制好的聚酰胺酸溶液,室温搅拌一定时间；将含钛酸钡粒子的聚酰胺酸溶液均匀地涂在干净的玻璃上,用涂膜器刮出一层均匀的膜,放入真空干燥箱中真空干燥,最后将复合膜从载玻片上剥离。在电阻炉中按照一定温度制度进行热处理后,自然冷却,即得聚酰亚胺/钛酸钡复合膜。本发明能够安全有效的提高钙钛矿的结晶度,提高钙钛矿复合膜的产量,大大降低了制备成本,且制备过程较为安全,保障了操作人员的安全。(The invention discloses a method for enhancing the crystallinity safety of perovskite, which comprises the following steps: taking dry barium titanate powder with equal molar mass and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC), and ultrasonically stirring for a certain time until the barium titanate powder is in a uniform milk-shaped suspension; adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature; the polyamic acid solution containing barium titanate particles is evenly coated on clean glass, a layer of even film is scraped by a film coater, the film is placed in a vacuum drying box for vacuum drying, and finally the composite film is peeled from a glass slide. And (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate composite film. The method can safely and effectively improve the crystallinity of the perovskite, improve the yield of the perovskite composite film, greatly reduce the preparation cost, ensure the safety of operators, and ensure the safety of the preparation process.)

1. A method for enhancing the safety of perovskite crystallinity, comprising the steps of:

1) taking dry barium titanate powder with equal molar mass and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC), and ultrasonically stirring for a certain time until the barium titanate powder is in a uniform milk-shaped suspension;

2) adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature;

3) uniformly coating the polyamic acid solution containing barium titanate particles on clean glass, and scraping a layer of uniform film by using a film coater;

4) placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide; and (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

2. The method as claimed in claim 1, wherein the polyamic acid solution in step 2) is prepared by respectively grinding and drying a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at high speed until no particulate matter exists, adding pyromellitic dianhydride, and stirring at room temperature for 8-12 h.

3. The method for enhancing the safety of perovskite crystallinity as claimed in claim 1, wherein the purity of N, N-dimethylacetamide in step 1) is above 99.9%.

4. The method for enhancing the crystallinity safety of perovskite according to claim 2, wherein pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether are ground and dried in a drying oven at a temperature of about 100 ℃ for 1-2 h.

5. The method for enhancing the safety of perovskite crystallinity as claimed in claim 2, wherein the pyromellitic dianhydride is added uniformly in small amount for a plurality of times, the drug is kept dry, and the temperature is controlled at 0-5 ℃ for about 1-2 hours.

6. The method for enhancing the safety of perovskite crystallinity as claimed in claim 2, wherein the polyamic acid solution is placed in an oven, the temperature is adjusted to 80 ℃ and kept for 2h, and the solvent is completely volatilized; and heating the oven, respectively adjusting the temperature to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling and keeping at room temperature to finish the imidization.

7. The method as claimed in claim 1, wherein the step 3) is performed by spin coating at a speed of 3000-.

Technical Field

The invention relates to the technical field of preparation of perovskite composite films, in particular to a method for enhancing the safety of perovskite crystallinity.

Background

Perovskite refers to a ceramic oxide, and the molecular general formula of the perovskite is ABO 3; the oxide is discovered at the earliest and is a calcium titanate (CaTiO3) compound existing in perovskite ore, so that the oxide is named, the perovskite type composite oxide ABO3 is a novel inorganic non-metallic material with unique physical and chemical properties, and the compound has a stable crystal structure, unique electromagnetic property and high activities of oxidation reduction, hydrogenolysis, isomerization, electrocatalysis and the like, so that the perovskite type composite oxide ABO3 has great development potential in the fields of environmental protection, industrial catalysis and the like as a novel functional material.

The perovskite composite oxide has a unique crystal structure, particularly a crystal defect structure and performance formed after doping, or can be applied to various fields such as solid fuel cells, solid electrolytes, sensors, high-temperature heating materials, solid resistors, redox catalysts replacing noble metals and the like, and becomes a research hotspot in the fields of chemistry, physics, materials and the like, barium titanate (BaTiO3) is a typical perovskite structure crystal, and the composite oxide of the barium titanate is a relatively common preparation product in industry.

However, in the prior art, the preparation of barium titanate composite oxide is difficult, which results in low yield of barium titanate composite crystal, high cost is often required for mass preparation, which greatly hinders the input and use of such perovskite composite oxide, and some material collision or high-pressure environment is often required in the preparation process, which is dangerous, so a method for enhancing the safety of perovskite crystallinity is proposed to solve the above problems.

Disclosure of Invention

The invention aims to solve the defects in the prior art, such as: the traditional perovskite composite oxide crystal is difficult to prepare, has higher cost and has certain dangerous preparation processes, and the proposed method is used for enhancing the safety of the crystallinity of the perovskite.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for enhancing the safety of perovskite crystallinity, comprising the steps of:

1) taking dry barium titanate powder with equal molar mass and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC), and ultrasonically stirring for a certain time until the barium titanate powder is in a uniform milk-shaped suspension;

2) adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature;

3) uniformly coating the polyamic acid solution containing barium titanate particles on clean glass, and scraping a layer of uniform film by using a film coater;

4) placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide; and (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

Preferably, the polyamic acid solution in step 2) is prepared by respectively grinding a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), drying, dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at a high speed until no particulate matter exists, adding pyromellitic dianhydride, and stirring at room temperature for 8-12 hours.

Preferably, the purity of the N, N-dimethylacetamide in the step 1) is more than 99.9%.

Preferably, the pyromellitic dianhydride (PM-DA) and the 4, 4-diaminodiphenyl ether are ground into fine powder and then placed in a drying oven to be dried for 1-2 hours at the temperature of about 100 ℃.

Preferably, the pyromellitic dianhydride is added uniformly in small amount for multiple times, the medicine is kept dry, the temperature is controlled to be 0-5 ℃, and the addition is finished for about 1-2 hours.

Preferably, the polyamic acid solution needs to be placed in an oven, the temperature is adjusted to 80 ℃ and kept for 2h, and the solvent is completely volatilized; and heating the oven, respectively adjusting the temperature to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling and keeping at room temperature to finish the imidization.

Preferably, the coating method in the step 3) is spin coating, the spin coating speed is 3000-4000r/min, the spin coating time is 20-30s, and the spin coating thickness is 300-400 nm.

Compared with the prior art, the invention has the beneficial effects that: the preparation of the barium titanate composite oxide crystal can be completed by adopting a precipitation method only through simple operations such as heating and stirring, so that the preparation cost and difficulty are greatly reduced, a dangerous preparation method such as a hydrothermal synthesis method and a high-energy ball milling method is not required, the danger in the preparation process is greatly reduced, and the safety of operators is improved.

Detailed Description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.

Example one

Step 1: taking 1-1 equimolar dry barium titanate powder and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC), performing ultrasonic stirring for 7 hours, wherein the solution is a uniform milk-shaped suspension, and the purity of the N, N-dimethylacetamide is more than 99.9%;

step 2: adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature; the polyamic acid solution is prepared by respectively grinding a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), drying, dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at a high speed until no granular substances exist, adding pyromellitic dianhydride, pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether, grinding, placing in a drying oven, drying at about 100 ℃ for 1h, uniformly adding a small amount of pyromellitic dianhydride for multiple times when adding, keeping the medicine dry, controlling the temperature at 5 ℃, finishing the addition for 1h, stirring at room temperature for 8h, placing the polyamic acid solution in an oven, adjusting the temperature to 80 ℃, keeping the temperature for 2h, and completely volatilizing the solvent; heating the oven, respectively adjusting to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling to room temperature to finish imidization;

and step 3: uniformly coating the polyamic acid solution containing barium titanate particles on clean glass, and scraping a layer of uniform film by using a film coater, wherein the coating mode is spin coating, the spin coating speed is 3000r/min, the spin coating time is 20s, and the spin coating thickness is 300 nm;

and 4, step 4: and (3) placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide. And (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

Example 2

Step 1: taking 1-1.5 molar mass of dried barium titanate powder and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC), and ultrasonically stirring for 6 hours to obtain a uniform milk-shaped suspension, wherein the purity of the N, N-dimethylacetamide is more than 99.9%;

step 2: adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature; the polyamic acid solution is prepared by respectively grinding and drying a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at a high speed until no granular substances exist, adding pyromellitic dianhydride, pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether, grinding, placing in a drying oven, drying at about 100 ℃ for 1h, uniformly adding a small amount of pyromellitic dianhydride for multiple times when adding, keeping the medicine dry, controlling the temperature at 3 ℃, finishing the addition for 1.5h, stirring at room temperature for 9h, placing the polyamic acid solution in an oven, adjusting the temperature to 80 ℃, keeping the temperature for 2h, and completely volatilizing the solvent; heating the oven, respectively adjusting to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling to room temperature to finish imidization;

and step 3: uniformly coating the polyamic acid solution containing barium titanate particles on clean glass, scraping a layer of uniform film by using a film coater, wherein the coating mode is spin coating, the spin coating speed is 3200r/min, the spin coating time is 22s, and the spin coating thickness is 320 nm;

and 4, step 4: placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide; and (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

EXAMPLE III

Step 1: taking 1-2 molar mass of dry barium titanate powder and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC) to perform ultrasonic stirring for 5 hours, wherein the solution is a uniform milk-shaped suspension, and the purity of the N, N-dimethylacetamide is more than 99.9%;

step 2: adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature; the polyamic acid solution is prepared by respectively grinding and drying a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at a high speed until no granular substances exist, adding pyromellitic dianhydride, pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether, grinding, placing in a drying oven, drying at about 100 ℃ for 1h, uniformly adding a small amount of pyromellitic dianhydride for multiple times when adding, keeping the medicine dry, controlling the temperature at 3 ℃, finishing the addition for 1.5h, stirring at room temperature for 10h, placing the polyamic acid solution in an oven, adjusting the temperature to 80 ℃, keeping the temperature for 2h, and completely volatilizing the solvent; heating the oven, respectively adjusting to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling to room temperature to finish imidization;

and step 3: uniformly coating the polyamic acid solution containing barium titanate particles on clean glass, and scraping a layer of uniform film by using a film coater, wherein the coating mode is spin coating, the spin coating speed is 3500r/min, the spin coating time is 26s, and the spin coating thickness is 350 nm;

and 4, step 4: placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide; and (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

Example four

Step 1: taking 1-3 molar mass of dry barium titanate powder and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC) to perform ultrasonic stirring for 3 hours, wherein the solution is a uniform milk-shaped suspension, and the purity of the N, N-dimethylacetamide is more than 99.9%;

step 2: adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature; the polyamic acid solution is prepared by respectively grinding a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), drying, dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at a high speed until no granular substances exist, adding pyromellitic dianhydride, pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether, grinding, placing in a drying oven, drying at about 100 ℃ for 1h, uniformly adding a small amount of pyromellitic dianhydride for multiple times when adding, keeping the medicine dry, controlling the temperature at 3 ℃ and finishing the addition for 2h, stirring at room temperature for 12h, placing the polyamic acid solution in an oven, adjusting the temperature to 80 ℃ and keeping the temperature for 2h, and completely volatilizing the solvent; heating the oven, respectively adjusting to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling to room temperature to finish imidization;

and step 3: uniformly coating the polyamic acid solution containing barium titanate particles on clean glass, scraping a layer of uniform film by using a film coater, wherein the coating mode is spin coating, the spin coating speed is 3600r/min, the spin coating time is 20s, and the spin coating thickness is 400 nm;

and 4, step 4: placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide; and (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

EXAMPLE five

Step 1: taking 2-1 molar mass of dried barium titanate powder and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC) to perform ultrasonic stirring for 9 hours, wherein the solution is a uniform milk-shaped suspension, and the purity of the N, N-dimethylacetamide is more than 99.9%;

step 2: adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature; the polyamic acid solution is prepared by respectively grinding a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), drying, dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at a high speed until no granular substances exist, adding pyromellitic dianhydride, pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether, grinding, placing in a drying oven, drying at about 100 ℃ for 1h, uniformly adding a small amount of pyromellitic dianhydride for multiple times when adding, keeping the medicine dry, controlling the temperature at 5 ℃ and finishing the addition for 2h, stirring at room temperature for 12h, placing the polyamic acid solution in an oven, adjusting the temperature to 80 ℃ and keeping the temperature for 2h, and completely volatilizing the solvent; heating the oven, respectively adjusting to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling to room temperature to finish imidization;

and step 3: uniformly coating the polyamic acid solution containing barium titanate particles on clean glass, and scraping a layer of uniform film by using a film coater, wherein the coating mode is spin coating, the spin coating speed is 3900r/min, the spin coating time is 28s, and the spin coating thickness is 360 nm;

and 4, step 4: placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide; and (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

EXAMPLE six

Step 1: taking 3-1 molar mass of dried barium titanate powder and N, N-dimethylacetamide, adding the barium titanate powder into N, N-Dimethylacetamide (DMAC) to perform ultrasonic stirring for 10 hours, wherein the solution is a uniform milk-shaped suspension, and the purity of the N, N-dimethylacetamide is more than 99.9%;

step 2: adding the suspension into the prepared polyamic acid solution, and stirring for a certain time at room temperature; the polyamic acid solution is prepared by respectively grinding a certain amount of pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether (ODA), drying, dissolving the dried 4, 4-diaminodiphenyl ether (ODA) in N, N-dimethyl acetamide, stirring at a high speed until no granular substances exist, adding pyromellitic dianhydride, pyromellitic dianhydride (PM-DA) and 4, 4-diaminodiphenyl ether, grinding, placing in a drying oven, drying at about 100 ℃ for 1h, uniformly adding a small amount of pyromellitic dianhydride for multiple times when adding, keeping the medicine dry, controlling the temperature at 5 ℃ and finishing the addition for 2h, stirring at room temperature for 12h, placing the polyamic acid solution in an oven, adjusting the temperature to 80 ℃ and keeping the temperature for 2h, and completely volatilizing the solvent; heating the oven, respectively adjusting to 120 ℃, 160 ℃, 200 ℃ and keeping for 1h by adopting a step method, adjusting the temperature to about 240 ℃ and keeping for 1h for imidization, and finally cooling to room temperature to finish imidization;

and step 3: uniformly coating a polyamic acid solution containing barium titanate particles on clean glass, and scraping a layer of uniform film by using a film coater, wherein the coating mode is spin coating, the spin coating speed is 4000r/min, the spin coating time is 30s, and the spin coating thickness is 400 nm;

and 4, step 4: placing the glass on a horizontal table, placing the glass in a vacuum drying box for vacuum drying, and finally stripping the composite film from the glass slide; and (3) performing heat treatment in a resistance furnace according to a certain temperature system, and naturally cooling to obtain the polyimide/barium titanate (PI/BaTiO3) composite film.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.