Preparation method of polymer conductive film

Abstract

The invention provides a preparation method of a polymer conductive film, which comprises the following steps: (1) blending a polymer, a styrene-maleic anhydride copolymer and an organic solvent to prepare a polymer solution, and preparing a polymer film by adopting an immersion precipitation phase inversion method; (2) soaking the polymer membrane in an aqueous solution containing amino sugar to obtain a grafted membrane of which the membrane surface and the body both contain aldehyde groups; and (3) reducing silver or copper hydroxide in the silver ammonia solution or the potassium sodium tartrate solution of copper hydroxide into silver with a conductive effect or cuprous oxide nanoparticles with a semiconductor effect by the aldehyde group to form a continuous structure with nanoparticles on the surface and in the body, thereby obtaining the'polymer / inorganic nano material 'hybrid conductive film. The conductive film is stable and durable, has excellent conductivity and can be used for conductive thin films, electromagnetic shielding materials and the like, the preparation method of the film is simple and easy to amplify, the reaction process is easy to observe, application and popularization are easy, and good industrialization prospects are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer functional membranes, and particularly to a preparation method of a polymer conductive membrane. Background Art

[0002] Nowadays, with the rapid development of electronic technology, people's demand for flexible, portable and wearable electronic devices is increasing day by day, and thin-film conductive materials have become the key materials to meet this demand. Polymer membranes have broad application prospects in the field of thin-film conductive materials due to their good flexibility, mechanical strength and easy processability. The "polymer / inorganic nanomaterial" hybrid membrane obtained by doping inorganic nanomaterials with conductive effects into polymers has both excellent conductive and mechanical properties.

[0003] The methods of hybridizing nanoparticles with conductive effects into polymer membranes include blending, co-precipitation, embedding, sol-gel and chemical deposition, etc. The blending method is simple to operate, but methods such as blending, embedding, sol-gel and co-precipitation have the problem that the added nanoparticles will affect the flexibility and mechanical strength of the hybrid membrane, and the nanoparticles are extremely prone to uneven distribution and aggregation in the matrix, resulting in discontinuous distribution, thus significantly reducing the conductive performance of the material; although the mechanical properties of the membrane can be maintained by the chemical deposition method, this method can only deposit the conductive component on the membrane surface and it is difficult to deposit it in the membrane body, that is, it is difficult to form a continuous conductive path, resulting in poor conductive performance of the membrane. Therefore, it is necessary to develop a preparation method of a polymer conductive hybrid membrane that is simple, in which conductive nanomaterials can form a continuous distribution in the membrane, so as to have good conductive performance and mechanical properties. Summary of the Invention

[0004] In view of this, the present invention provides a method for preparing a polymer conductive hybrid membrane by a redox method. First, amino sugars are introduced into the polymer membrane body and surface by chemical grafting (the amino group in the amino sugar forms an amide group and a carboxyl group with the anhydride group in the polymer membrane), and then the aldehyde group in the amino sugar in-situ reduces the silver ions in the silver ammonia solution or the copper hydroxide in the Fehling reagent solution to form silver nanoparticles or cuprous oxide nanoparticles respectively. The nanoparticles not only have strong interactions with the nitrogen atoms of the amide groups and the oxygen atoms in the carboxyl groups of the polymer membrane, thus enhancing the binding force between the nano-conductive particles and the polymer matrix, but also the nano-conductive particles can be evenly distributed on the surface and in the matrix of the polymer membrane to form a continuous conductive path, making the "polymer / inorganic nanomaterial" hybrid membrane have good stability, strong durability and high conductivity and good electromagnetic shielding performance.

[0005] The present invention provides a preparation method of a polymer conductive hybrid membrane, and the technical solution adopted is:

[0006] (1) Dissolve the polymer and styrene-maleic anhydride copolymer in an organic solvent, and stir evenly at 50 °C to 80 °C for 4 hours to 12 hours to prepare a polymer solution. Scrape the solution on a glass plate, and use the immersion precipitation phase inversion method to obtain a polymer membrane;

[0007] (2) Immerse the above polymer membrane in an amino sugar solution at 45 °C to 80 °C, take it out and remove the excess amino sugar on the membrane surface to obtain a treated grafted membrane;

[0008] (3) Immerse the above grafted membrane in a silver ammonia or Fehling reagent solution, carry out an in-situ reduction reaction at 30 °C to 75 °C for 0.5 hours to 10 hours, take it out and remove the excess silver ammonia or Fehling reagent on the membrane surface, wash it with deionized water and dry it to obtain a "polymer / silver" or "polymer / cuprous oxide" conductive hybrid membrane.

[0009] In step (1), the polymer is one of polyvinylidene fluoride, polysulfone, polyethersulfone, and polyacrylonitrile.

[0010] The organic solvent can be selected from the commonly used organic solvents in the art, and is preferably one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and dimethyl sulfoxide.

[0011] The temperature of the polymer solution is 50 °C to 80 °C.

[0012] The weight percentage concentration of the polymer solution is 10% to 25%. Among them, the weight percentage concentration of the polymer solution refers to the weight percentage of the total weight of the polymer and the styrene-maleic anhydride copolymer in the solution.

[0013] In step (2), the amino sugar is glucosamine or galactosamine.

[0014] The immersion time in the aqueous amino sugar solution is 0.5 hours to 9 hours.

[0015] The soaking temperature is 50 °C to 80 °C.

[0016] In step (3), the concentration of the silver ammonia or Fehling reagent solution is not strictly limited. Generally, the higher the concentration of the silver ammonia or Fehling reagent solution, the shorter the in-situ reduction reaction time, and the lower the concentration, the longer the in-situ reduction reaction time. The preferred concentration is 0.01 mol / L to 1 mol / L, and the soaking time is 0.5 hours to 10 hours.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) In the conductive film provided by the present invention, the binding force between the conductive particles and the polymer film is strong, and the conductive particles can be uniformly distributed on the film surface and inside the polymer matrix to form a continuous conductive structure. The polymer conductive film has good stability, strong durability, high flexibility, high conductivity and excellent electromagnetic shielding efficiency.

[0019] (2) The polymer conductive film of the present invention is obtained by an in-situ reduction method. The process is simple, the requirements for equipment are low, the reaction is carried out under normal pressure environment, it is easy to observe during the reaction, it can be prepared in a large area, and it is easy to promote and apply. It is a good method for preparing polymer conductive films. Specific embodiments

[0020] The present invention will be described in more detail through the following examples, but the examples do not constitute a limitation to the present invention.

[0021] Example 1

[0022] 6 g of polyvinylidene fluoride and 0.4 g of styrene-maleic anhydride copolymer were dissolved in N,N-dimethylformamide, and slowly stirred at 50 °C for 12 hours to prepare a polymer solution with a weight percentage of 10%. After standing for 24 hours to remove bubbles, this solution was used as the casting solution, which was cast on a glass plate and immersed in water for 12 hours and then taken out, that is, a polymer film was prepared by the immersion precipitation phase inversion method.

[0023] The above polymer film was placed in a glucosamine solution and immersed at 45 °C for 9 hours and then taken out to obtain a grafted film.

[0024] The above grafted film was put into a 0.01 mol / L silver ammonia solution, immersed for 10 hours and then taken out, washed several times with deionized water, and finally dried to obtain a polymer conductive film. Its conductivity σ = 840 S / cm was measured by a four-probe conductivity meter; its electromagnetic shielding efficiency value was 76 dB measured by a vector network analyzer.

[0025] Example 2

[0026] 6 g of polysulfone and 1.2 g of styrene-maleic anhydride copolymer were dissolved in N,N-dimethylacetamide, and slowly stirred at 60 °C for 6 hours to prepare a casting solution with a weight percentage of 20%. After standing for 24 hours to remove bubbles, this solution was used as the casting solution, which was cast on a glass plate and immersed in water for 12 hours and then taken out, that is, a polymer film was prepared by the immersion precipitation phase inversion method.

[0027] The above polymer film was placed in a galactosamine solution and immersed at 60 °C for 2 hours and then taken out to obtain a grafted film.

[0028] The above grafted film was placed in a 0.2 mol / L silver ammonia solution, taken out after soaking for 2 hours, washed several times with deionized water, and finally dried to obtain a polymer conductive film. Its conductivity σ = 910 S / cm was measured using a four-probe conductivity meter; its electromagnetic shielding effectiveness value was measured to be 82 dB using a vector network analyzer.

[0029] Example 3

[0030] 6 g of polyethersulfone and 1.6 g of styrene-maleic anhydride copolymer were dissolved in N-methylpyrrolidone, and slowly stirred at 80 °C for 4 hours to prepare a casting solution with a weight percentage of 25%. After standing for 24 hours to remove bubbles, this solution was used as the casting solution, which was blade-coated on a glass plate and taken out after being immersed in water for 12 hours, that is, a polymer film was prepared by the immersion precipitation phase inversion method.

[0031] The above polymer film was placed in a glucosamine solution, taken out after soaking at 80 °C for 1 hour to obtain a grafted film.

[0032] The above grafted film was placed in a 0.5 mol / L Fehling's reagent, taken out after soaking for 0.5 hour, washed several times with deionized water, and finally dried to obtain a polymer conductive film. Its conductivity σ = 290 S / cm was measured using a four-probe conductivity meter; its electromagnetic shielding effectiveness value was measured to be 32 dB using a vector network analyzer.

[0033] Example 4

[0034] 6 g of polyacrylonitrile and 0.4 g of styrene-maleic anhydride copolymer were dissolved in dimethyl sulfoxide, and slowly stirred at 50 °C for 12 hours to prepare a polymer solution with a weight percentage of 10%. After standing for 24 hours to remove bubbles, this solution was used as the casting solution, which was blade-coated on a glass plate and taken out after being immersed in water for 12 hours, that is, a polymer film was prepared by the immersion precipitation phase inversion method.

[0035] The above polymer film was placed in a galactosamine solution, taken out after soaking at 45 °C for 9 hours to obtain a polymer film.

[0036] The above grafted film was placed in a 1 mol / L Fehling's reagent, taken out after soaking for 10 hours, washed several times with deionized water, and finally dried to obtain a polymer conductive film. Its conductivity σ = 180 S / cm was measured using a four-probe conductivity meter; its electromagnetic shielding effectiveness value was measured to be 28 dB using a vector network analyzer.

[0037] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made using the content of the specification of the present invention, or directly or indirectly applying to other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A method for a polymer conductive film, characterized in that: It includes the following steps: (1) Dissolve the polymer and styrene-maleic anhydride copolymer in an organic solvent, and prepare a polymer solution at 50°C to 80°C. After the solution is left standing for defoaming, it is blade-coated on a glass plate, and a polymer membrane is obtained by the immersion precipitation phase inversion method; (2) Immerse the above polymer membrane in an aqueous solution containing amino sugar at 45°C to 80°C, take it out and remove the excess amino sugar on the membrane surface to obtain a treated grafted membrane; (3) Immerse the above grafted membrane in a silver ammonia or potassium sodium tartrate (Fehling's reagent) solution of copper hydroxide, carry out an in-situ reduction reaction at 30°C to 75°C for 0.5 hour to 10 hours, take it out and remove the excess silver ammonia or Fehling's reagent on the membrane surface, wash it with deionized water and then air-dry it to obtain a polymer conductive membrane.

2. The method for preparing a polymer conductive film according to claim 1, characterized in that, In step (1), the polymer is one of polyvinylidene fluoride, polysulfone, polyethersulfone, and polyacrylonitrile.

3. The preparation method according to claim 1, characterized in that, In step (1), the organic solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and dimethyl sulfoxide.

4. The preparation method according to claim 1, wherein In step (1), the temperature of the polymer solution is 50°C to 80°C.

5. The preparation method according to claim 1, characterized in that, In step (1), the weight percentage concentration of the polymer solution is 10% to 25%.

6. The preparation method according to claim 1, characterized in that, In step (2), the immersion temperature is 45°C to 80°C.

7. The preparation method according to claim 1, wherein In step (2), the amino sugar is one of glucosamine or galactosamine.

8. The preparation method according to claim 1, characterized in that, In step (3), the concentration of the silver ammonia or Fehling's reagent solution is 0.01 mol / L to 1 mol / L.

9. The preparation method according to claim 1, wherein In step (3), the in-situ reduction reaction temperature is 30°C to 75°C.

10. The preparation method according to claim 1, characterized in that, In step (3), the in-situ reduction reaction time is 0.5 hour to 10 hours.