Flaky polypyrrole with adjustable conductivity, preparation method and application of flaky polypyrrole in terahertz absorption field

Abstract

The invention discloses flaky polypyrrole with adjustable conductivity, a preparation method and application of the flaky polypyrrole in the field of terahertz absorption. The method comprises the following steps: dispersing sodium myristoyl glutamate in absolute ethyl alcohol, stirring and uniformly dispersing by utilizing ultrasonic waves, injecting a pyrrole monomer into a sodium myristoyl glutamate solution, continuously stirring and ultrasonically dispersing, then adding a certain amount of deionized water, and continuously stirring under an ice bath condition; and adding an oxidizing agent, and stirring for reaction to obtain the conductive polypyrrole with the sheet structure. According to the preparation method, pyrrole polymerization is induced to form polypyrrole with a sheet structure by utilizing a chemical effect between the sodium myristoyl glutamate and a pyrrole monomer, and the sodium myristoyl glutamate plays a role of a seed template. The prepared flaky polypyrrole can obtain good conductivity and has an excellent terahertz wave absorption characteristic.

Description

Technical Field

[0001] The invention relates to a conductive polymer material, in particular to a conductive polypyrrole with a sheet structure prepared by in-situ polymerization using sodium myristoyl glutamate. The high-conductivity sheet polypyrrole can be applied to the field of terahertz absorption. Background Art

[0002] Conductive polypyrrole is a common conductive polymer with a typical rigid conjugated large π bond structure, thus showing good conductivity. Its conductivity can reach 10 2 -10 3 S / cm. The conductivity of polypyrrole can be controlled by changing the type and concentration of doped ions and polymerization conditions. Polypyrrole has broad application prospects in electrochemistry, biomaterials, electromagnetic shielding, gas separation and other fields. The microscopic morphology of polypyrrole is diverse, including but not limited to granular, film-like, rod-like, tubular, polygonal box-like, sheet-like and fibrous. These changes in microscopic morphology are mainly affected by various synthesis conditions, such as the amount of oxidant, synthesis temperature, type of dopant, etc.

[0003] At present, the preparation methods of polypyrrole are mainly divided into two categories: chemical oxidation method and electrochemical synthesis method. Among them, the chemical oxidation method is to add an oxidant to the aqueous solution to make the pyrrole monomer undergo polymerization reaction to generate polypyrrole. The synthesis process of this method is relatively simple, the cost is low, and it is suitable for large-scale production. The chemical oxidation method of polypyrrole can be subdivided into the following methods: solution polymerization, emulsion polymerization, template polymerization, and enzyme catalysis. Among them, the template polymerization method uses a template with a specific structure to control the morphology and size of polypyrrole. In this method, the pyrrole monomer undergoes polymerization reaction in the pores or surface of the template to generate polypyrrole with a specific morphology and size. The template polymerization method can prepare polypyrrole materials with complex structures, such as porous materials, nanowires, nanosheets, nanotubes, etc.

[0004] Template polymerization can be further divided into hard template method and soft template method according to the type of template. The hard template method uses a solid material with a special internal or external morphology as a template to provide guidance and restriction for the growth of polypyrrole, thereby preparing a polypyrrole material with a specific morphology and size. The soft template method uses surfactant molecules, block copolymers, etc. as templates, adsorbs pyrrole monomers onto the template surface or pores through physical or chemical effects, and then initiates the polymerization reaction. The advantages of the soft template method are that the template preparation is simple, the experimental methods and equipment used are not complicated, and the template is easy to remove. In addition, the soft template has a variety of morphologies, which provides options for preparing conductive polymers with different morphologies.

[0005] In some key application fields, the electrical conductivity of polypyrrole often directly affects the performance of the final product. For example, in the field of electronic devices, the electrical conductivity of polypyrrole directly affects the performance and efficiency of electronic devices; in the field of sensors, the electrical conductivity of polypyrrole determines the sensitivity and response speed of sensors; in the field of energy storage, the electrical conductivity of polypyrrole directly affects the charge and discharge performance and cycle stability of batteries and capacitors; in the field of electromagnetic protection, the electrical conductivity of polypyrrole directly affects the frequency range and wave absorption effect of wave absorption. Therefore, how to develop a method for preparing polypyrrole with adjustable conductivity that is simple in process, easy to process, and has controllable morphology and size is an urgent problem to be solved by technicians in this field. Summary of the invention

[0006] The purpose of the present invention is to provide a sheet-like polypyrrole with adjustable conductivity, a preparation method and application thereof in the field of terahertz absorption. The polypyrrole obtained by the preparation method has uniform morphology and controllable conductivity.

[0007] In order to achieve the above-mentioned invention object, the technical solution is provided as follows:

[0008] A method for preparing a sheet-like polypyrrole with adjustable conductivity, comprising the following steps:

[0009] (1) dispersing sodium myristoyl glutamate in anhydrous ethanol, stirring and ultrasonically dispersing the mixture evenly;

[0010] (2) injecting the pyrrole monomer into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding a certain amount of deionized water, and placing the reaction system in an ice bath and continuing to stir for a period of time;

[0011] (3) slowly adding the oxidant to the reaction system in step (2), mixing evenly, stirring, and repeatedly washing the obtained product with deionized water and ethanol, and drying it in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0012] Furthermore, the concentration of sodium myristoyl glutamate in step (1) is 0.1-2 mg / mL.

[0013] Furthermore, the pyrrole monomer in step (2) is redistilled before use.

[0014] Furthermore, the mass ratio of sodium myristoyl glutamate to pyrrole monomer is 1:10-1:1.

[0015] Furthermore, in step (3), the oxidant includes one or more of ammonium persulfate, potassium persulfate, anhydrous ferric chloride, ferric nitrate nonahydrate, and anhydrous ferric sulfate.

[0016] Furthermore, the stirring speed during the reaction in step (3) is 100 r / min-1000 r / min.

[0017] Furthermore, the molar ratio of pyrrole to the oxidant is 1:1-1:4.

[0018] Furthermore, the drying temperature in step (3) is 60° C. and the drying time is 12 h.

[0019] The present invention also provides an application of a sheet-like polypyrrole with adjustable conductivity in the field of terahertz absorption. The sheet-like polypyrrole has a length of 10 μm, a width of 3 μm and a thickness of 500 nm.

[0020] Compared with the prior art, the present invention has many significant technical advantages, which are specifically reflected in the following aspects:

[0021] (1) In terms of preparation technology, the present invention adopts a unique and innovative preparation method, so that the polypyrrole obtained has an extremely uniform morphology. This uniformity is not only reflected in the highly consistent size and shape of the polypyrrole particles, but also ensures that they are evenly distributed in the material, effectively avoiding the occurrence of agglomeration. More advanced is that by accurately controlling various parameters in the preparation process, the preparation method of the present invention achieves precise control of the electrical conductivity of polypyrrole. This means that, according to specific application requirements, the electrical conductivity can be flexibly adjusted to the optimal range, providing a solid material basis for the wide application of materials in the fields of electronic devices, sensors, etc.

[0022] (2) In terms of performance, the sheet-like polypyrrole disclosed in the present invention exhibits excellent terahertz absorption characteristics. Specifically, the maximum effective absorption bandwidth of the material in the terahertz frequency band is less than or equal to -10dB, reaching an astonishing 5THz, which is far higher than similar materials and opens up new possibilities for the design and application of terahertz wave absorption materials. At the same time, its maximum absorption intensity is as high as -40dB. This excellent absorption performance makes the present invention have great application potential in the fields of terahertz stealth technology, terahertz communication shielding, etc.

[0023] (3) In terms of preparation mechanism, the present invention cleverly utilizes the special chemical reaction between sodium myristoyl glutamate and pyrrole monomers, through which the pyrrole monomers are induced to polymerize to form polypyrrole with a unique sheet structure. In this process, sodium myristoyl glutamate not only plays a key role as a seed template, but also promotes the orderly arrangement and polymerization between pyrrole monomers, thereby ensuring the structural stability and performance superiority of the final product. This innovative preparation strategy not only simplifies the preparation process and reduces production costs, but also enables the prepared sheet polypyrrole to have excellent terahertz wave absorption characteristics while maintaining good electrical conductivity, thereby achieving a dual improvement in material performance and preparation efficiency.

[0024] In summary, the present invention has demonstrated significant technical advantages in many aspects such as preparation process, performance and preparation mechanism, and has brought a revolutionary breakthrough in the research and development and application of polypyrrole materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 The microscopic morphology of the product obtained in Example 1 of the present invention observed under a scanning electron microscope.

[0027] Figure 2 This is the X-ray diffraction pattern of the product obtained in Example 2 of the present invention.

[0028] Figure 3 This is the infrared spectrum of the product obtained in Example 3 of the present invention.

[0029] Figure 4 This is a terahertz absorption spectrum diagram of the product obtained in Example 4 of the present invention. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In order to better understand the present invention, the present invention is further described below through the following examples, but it should not be understood as limiting the present invention. Some non-essential improvements and adjustments made by technicians in this field according to the above invention content are also considered to fall within the protection scope of the present invention.

[0032] The pyrrole used in the following examples was redistilled before use.

[0033] Example 1

[0034] A method for preparing a sheet-like polypyrrole with adjustable conductivity comprises the following steps:

[0035] (1) Disperse 38 mg of sodium myristoyl glutamate (0.1 mmol) in 15 mL of anhydrous ethanol, stir and disperse evenly by ultrasonication;

[0036] (2) injecting 134 mg of pyrrole monomer (2.0 mmol) into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding 60 mL of deionized water, and placing the reaction system in an ice bath (0° C.) and continuing to stir for a period of time;

[0037] (3) 304 mg of ammonium persulfate (2 mmol) was slowly added to the reaction system in step (2), mixed evenly, stirred at a speed of 100 r / min, and reacted for 2 h. The obtained product was repeatedly rinsed with deionized water and ethanol, and dried in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0038] Example 2

[0039] A method for preparing a sheet-like polypyrrole with adjustable conductivity comprises the following steps:

[0040] (1) Disperse 38 mg of sodium myristoyl glutamate (0.1 mmol) in 15 mL of anhydrous ethanol, stir and disperse evenly by ultrasonication;

[0041] (2) injecting 134 mg of pyrrole monomer (2.0 mmol) into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding 60 mL of deionized water, and placing the reaction system in an ice bath (0° C.) and continuing to stir for a period of time;

[0042] (3) 304 mg of ammonium persulfate (2 mmol) was slowly added to the reaction system in step (2), mixed evenly, stirred at a speed of 200 r / min, and reacted for 2 h. The obtained product was repeatedly rinsed with deionized water and ethanol, and dried in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0043] Example 3

[0044] A method for preparing a sheet-like polypyrrole with adjustable conductivity comprises the following steps:

[0045] (1) Disperse 38 mg of sodium myristoyl glutamate (0.1 mmol) in 15 mL of anhydrous ethanol, stir and disperse evenly by ultrasonication;

[0046] (2) injecting 134 mg of pyrrole monomer (2.0 mmol) into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding 60 mL of deionized water, and placing the reaction system in an ice bath (0° C.) and continuing to stir for a period of time;

[0047] (3) 304 mg of ammonium persulfate (2 mmol) was slowly added to the reaction system in step (2), mixed evenly, stirred at a speed of 400 r / min, and reacted for 2 h. The obtained product was repeatedly rinsed with deionized water and ethanol, and dried in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0048] Example 4

[0049] A method for preparing a sheet-like polypyrrole with adjustable conductivity comprises the following steps:

[0050] (1) Disperse 38 mg of sodium myristoyl glutamate (0.1 mmol) in 15 mL of anhydrous ethanol, stir and disperse evenly by ultrasonication;

[0051] (2) injecting 134 mg of pyrrole monomer (2.0 mmol) into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding 60 mL of deionized water, and placing the reaction system in an ice bath (0° C.) and continuing to stir for a period of time;

[0052] (3) 304 mg of ammonium persulfate (2 mmol) was slowly added to the reaction system in step (2), mixed evenly, stirred at a speed of 600 r / min, and reacted for 2 h. The obtained product was repeatedly rinsed with deionized water and ethanol, and dried in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0053] Example 5

[0054] A method for preparing a sheet-like polypyrrole with adjustable conductivity comprises the following steps:

[0055] (1) Disperse 38 mg of sodium myristoyl glutamate (0.1 mmol) in 15 mL of anhydrous ethanol, stir and disperse evenly by ultrasonication;

[0056] (2) injecting 134 mg of pyrrole monomer (2.0 mmol) into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding 60 mL of deionized water, and placing the reaction system in an ice bath (0° C.) and continuing to stir for a period of time;

[0057] (3) 304 mg of ammonium persulfate (2 mmol) was slowly added to the reaction system in step (2), mixed evenly, stirred at a speed of 800 r / min, and reacted for 2 h. The obtained product was repeatedly rinsed with deionized water and ethanol, and dried in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0058] Example 6

[0059] A method for preparing a sheet-like polypyrrole with adjustable conductivity comprises the following steps:

[0060] (1) Disperse 38 mg of sodium myristoyl glutamate (0.1 mmol) in 15 mL of anhydrous ethanol, stir and disperse evenly by ultrasonication;

[0061] (2) injecting 134 mg of pyrrole monomer (2.0 mmol) into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding 60 mL of deionized water, and placing the reaction system in an ice bath (0° C.) and continuing to stir for a period of time;

[0062] (3) 304 mg of ammonium persulfate (2 mmol) was slowly added to the reaction system in step (2), mixed evenly, stirred at a speed of 1000 r / min, and reacted for 2 h. The obtained product was repeatedly rinsed with deionized water and ethanol, and dried in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0063] Example 7

[0064] A method for preparing a sheet-like polypyrrole with adjustable conductivity comprises the following steps:

[0065] (1) Disperse 76 mg of sodium myristoyl glutamate (0.2 mmol) in 15 mL of anhydrous ethanol, stir and disperse evenly using ultrasonic method;

[0066] (2) injecting 134 mg of pyrrole monomer (2.0 mmol) into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding 60 mL of deionized water, and placing the reaction system in an ice bath (0° C.) and continuing to stir for a period of time;

[0067] (3) 304 mg of ammonium persulfate (2 mmol) was slowly added to the reaction system in step (2), mixed evenly, stirred at a speed of 1000 r / min, and reacted for 2 h. The obtained product was repeatedly rinsed with deionized water and ethanol, and dried in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

[0068] The performance parameters of the sheet-like polypyrrole obtained in Examples 1-7 are shown in Figure 1:

[0069]

[0070] Note: The thickness of polypyrrole was observed by scanning electron microscopy, and the conductivity was measured by four-probe method.

[0071] It can be seen from Table 1 that: through the analysis of the conductivity of the sheet polypyrrole in the embodiment, it can be seen that the conductivity of the sheet polypyrrole can be changed by adjusting the rotation speed during the experiment. Within 0-600r / min, increasing the rotation speed will increase the conductivity; at 600r / min, the conductivity of the sheet polypyrrole reaches the maximum. When it exceeds 600r / min, increasing the rotation speed will reduce the conductivity. In addition, controlling the addition amount of sodium myristate glutamate can also change the conductivity of the sheet polypyrrole. Therefore, the method introduced in the present invention can achieve controllable conductivity of sheet polypyrrole.

[0072] Finally, it should be noted that through the embodiments described in the patent of the present invention, ordinary technicians in this field can make similar changes and adjustments under the enlightenment of the present invention without violating the spirit and claims of the present invention, and such changes fall within the scope of protection of the present invention.

Claims

1. A method for preparing a sheet-like polypyrrole with adjustable conductivity, characterized in that: Here are the steps: (1) dispersing sodium myristoyl glutamate in anhydrous ethanol, stirring and ultrasonically dispersing the mixture evenly; (2) injecting the pyrrole monomer into the sodium myristoyl glutamate solution of step (1), stirring and ultrasonically dispersing to form a reaction system, adding a certain amount of deionized water, and placing the reaction system in an ice bath and continuing to stir for a period of time; (3) slowly adding the oxidant to the reaction system in step (2), mixing evenly, stirring to react, and repeatedly washing the obtained product with deionized water and ethanol, and drying it in a vacuum drying oven to obtain a conductive polypyrrole with a sheet structure.

2. The method for preparing the sheet-like polypyrrole with adjustable conductivity according to claim 1, characterized in that: The concentration of sodium myristoyl glutamate in step (1) is 0.1-2 mg / mL.

3. The method for preparing the sheet-like polypyrrole with adjustable conductivity according to claim 1, characterized in that: In step (2), the pyrrole monomer is redistilled before use.

4. The method for preparing the sheet-like polypyrrole with adjustable conductivity according to claim 1, characterized in that: The mass ratio of sodium myristoyl glutamate to pyrrole monomer is 1:10-1:

1.

5. The method for preparing the sheet-like polypyrrole with adjustable conductivity according to claim 1, characterized in that: In step (3), the oxidant includes one or more of ammonium persulfate, potassium persulfate, anhydrous ferric chloride, ferric nitrate nonahydrate, and anhydrous ferric sulfate.

6. The method for preparing the sheet-like polypyrrole with adjustable conductivity according to claim 1, characterized in that: The stirring speed during the reaction in step (3) is 100 r / min-1000 r / min.

7. The method for preparing the sheet-like polypyrrole with adjustable conductivity according to claim 1, characterized in that: The molar ratio of pyrrole to the oxidant is 1:1-1:

4.

8. The method for preparing the sheet-like polypyrrole with adjustable conductivity according to claim 1, characterized in that: The drying temperature in step (3) is 60° C. and the drying time is 12 h.

9. A sheet-like polypyrrole with adjustable conductivity prepared according to the method according to any one of claims 1 to 8.

10. Use of the conductivity-adjustable sheet-like polypyrrole according to claim 9 in the field of terahertz absorption.

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