CN110184673B

CN110184673B - Polypyrrole nano fiber material doped with triazophos pentaphosphoric acid, preparation method and application

Info

Publication number: CN110184673B
Application number: CN201910486167.6A
Authority: CN
Inventors: 谢阿明; 孙梦潇; 吴凡
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2019-06-05
Filing date: 2019-06-05
Publication date: 2021-11-09
Anticipated expiration: 2039-06-05
Also published as: CN110184673A

Abstract

The invention discloses a polypyrrole nano-fiber material doped with triazophosphoric acid, a preparation method and application. The nanofiber material is doped with triazophosphoric acid, so that the nanofiber material has high dielectricity and excellent wave-absorbing performance, and the real value of the dielectric constant of the nanofiber material under a test frequency band is kept between 6 and 9; when the test thickness is 2 mm, the absorption peak is 47 dB, and the nanofiber material has a chiral spiral hollow structure. The nano-fiber prepared by the invention has simple preparation process and short reaction time, and can be produced on a large scale.

Description

Polypyrrole nano fiber material doped with triazophos pentaphosphoric acid, preparation method and application

Technical Field

The invention belongs to the field of material preparation, and particularly relates to a high-dielectric-property chiral spiral hollow-structure polypyrrole nano fiber doped with triazophosphoric acid and a preparation method thereof.

Background

Polypyrrole as a common conductive polymer is widely used in supercapacitors due to its simple synthesis, high stability, low biotoxicity, environmental friendliness and other characteristicsJ. Mater. Chem. C2018, 6(6), 2482 and 2493), and lithium battery(s) ((II)Adv. Eng. Mater.2016, 6(13), 1600256), and the like. The morphology of polypyrrole is often presented as nano/micro particles (Adv. Mater., 2018, 30(35), 1802731; J. Appl. Phys2015, 118, 204105), hydrogels (a-b)ACS Nano2014, 8(10), 10066-Appl. Phys. Lett.2015, 106, 222902.), etc.; because of the advantages of high aspect ratio, polypyrrole one-dimensional nanomaterials are gradually paid attention to by researchers, such as polypyrrole one-dimensional nanofibers ()Langmuir2014, 30(26), 7778-Nanotechnol.2017, 28, 315701.) and the like have good electromagnetic absorption performance. At present, polypyrrole is modified by adopting a doping mode, so that certain properties of the polypyrrole are improved; common doping materials include: such as polystyrene sulfonic acid (or sulfonate) ((R))ACS Appl. Mater. Interfaces, 2019, 11(4), 4258-4267）、（J. Mater. Chem. A2014, 2(3), 859-865), acetic acid (2014, 2(3), and acetic acid (865)Biomacromolecules2007, 8(1), 182-187), etc. Therefore, the one-dimensional conductive polymer with excellent performance can be obtained by comprehensively utilizing the advantages of the one-dimensional nano fiber and the acid doping method.

Disclosure of Invention

The invention aims to provide a preparation method of a polypyrrole nano-fiber material with a high-dielectric-property chiral spiral hollow structure doped with triazophosphoric acid.

The technical solution for realizing the purpose of the invention is as follows: the polypyrrole nano-fiber material doped with the triazophos is doped with the triazophos, has high dielectricity (the value of the real part of a dielectric constant under a test frequency band is kept between 6 and 9) and excellent wave-absorbing performance (when the test thickness is 2 mm, an absorption peak is 47 dB), and has a chiral spiral hollow structure.

The preparation method of the nanofiber material comprises the following steps:

step 1: dispersing a chiral reagent and a pyrrole monomer in a certain volume of methanol according to a molar ratio of 1:40, adding deionized water with the volume 5 times that of the methanol, stirring for a period of time, then dripping into triazophosphoric acid with the molar amount 50 times that of the chiral induction reagent, stirring for a period of time to form a uniformly dispersed solution, and carrying out ice bath;

step 2: dropping ammonium persulfate in a molar amount 40 times that of the chiral reagent into the uniformly dispersed solution in the ice bath in the step 1, and stirring for a period of time;

and step 3: and washing the obtained product by deionized water/ethanol, and drying.

Furthermore, in the step 1, the mass concentration of the pyrrole monomer is 2.20-2.50 g/L.

Further, in step 3, the drying temperature is not higher than 60 ℃.

Compared with the prior art, the invention has the advantages that:

(1) the nano-fiber prepared by the invention has simple preparation process and short reaction time, and can be produced on a large scale.

(2) The nano fiber prepared by the invention has higher dielectric constant in a higher frequency band and excellent wave-absorbing performance under the same test frequency band and thickness compared with undoped nano fiber by doping the trinitrogen pentaphosphoric acid.

Drawings

Fig. 1 is a scanning electron microscope picture (a) and a transmission electron microscope picture (b) of example 1.

FIG. 2 shows a dielectric constant test chart (a) and a wave-absorbing property chart (b) of example 1.

Fig. 3 is a scanning electron microscope picture (a) and a transmission electron microscope picture (b) of comparative example 1.

FIG. 4 is a dielectric constant test chart (a) and a wave-absorbing property chart (b) of comparative example 1.

Fig. 5 is a scanning electron microscope picture (a) and a transmission electron microscope picture (b) of comparative example 2.

FIG. 6 is a dielectric constant test pattern (a) and a wave-absorbing property pattern (b) of comparative example 2.

Fig. 7 is a scanning electron microscope picture (a) and a transmission electron microscope picture (b) of comparative example 3.

FIG. 8 is a dielectric constant test pattern (a) and a wave-absorbing property pattern (b) of comparative example 3.

Detailed Description

The invention will now be further described with reference to the following examples and drawings:

example 1: chiral induction reagent (23 mg, 0.06 mmol), pyrrole monomer (0.161 g, 2.4 mmol) and triazophos (1.71 g, 3 mmol) were dissolved in 12 mL of methanol, and 60 mL of deionized water was added to the solution and stirred for 10 minutes to obtain a uniform dispersion. The uniform dispersion was placed in an ice bath, and ammonium persulfate (0.548 g, 2.4 mmol) was added dropwise to the dispersion, followed by stirring for 30 minutes to obtain a product. And (3) cleaning the product by deionized water/ethanol, and drying in a vacuum drying oven to obtain the camphor sulfonic acid doped high-conductivity chiral spiral hollow structure polypyrrole nano-fiber, wherein the doping acid is excessive, and the microstructure of the camphor sulfonic acid doped high-conductivity chiral spiral hollow structure polypyrrole nano-fiber is shown in figure 1.

The nano-fiber accounting for 10 percent of the total mass of the composite material is uniformly mixed with paraffin, and the mixture is pressed into an annular die (the height is 2.0 mm, the outer diameter is 7.0 mm, and the inner diameter is 3.0 mm) to prepare a sample, and according to the test of a vector network analyzer, the dielectric constant and the wave absorbing performance of the sample are shown in the attached figure 2.

Comparative example 1: similar to example 1, but with the molar amount of doped triazophos exchanged for p-polystyrene sulfonic acid. Finally obtaining the polypyrrole nano-fiber with the polystyrene sulfonic acid doped high-conductivity chiral spiral hollow structure, wherein the micro-morphology of the polypyrrole nano-fiber is shown in the attached figure 3.

Mixing with paraffin according to the ratio of nanofiber accounting for 10% of the total mass of the composite material, pressing into an annular mold (height 2.0 mm, outer diameter 7.0 mm, inner diameter 3.0 mm) to obtain a sample, and testing with a vector network analyzer to obtain the dielectric constant shown in figure 4.

Compared with the nanofiber prepared in example 1, the nanofiber prepared in the comparative example has the morphological characteristics that in the comparison of fig. 1 and 3, the polypyrrole nano material in example 1 is in a spiral hollow nanofiber state due to different types of doped acids, and the material in fig. 3 is an irregular-shaped nano material. The dielectric constants of the polypyrrole nano-fiber and the polypyrrole nano-fiber are shown in fig. 2 (a) and 4 (a), the dielectric constant of the polypyrrole nano-fiber with the triazophosphoric acid doped chiral hollow structure is higher under the same condition, and compared with the polypyrrole nano-fiber and the polypyrrole nano-fiber, the polypyrrole nano-fiber in the embodiment 1 has higher dielectric properties. The wave absorbing performance of the fiber and the fiber is shown in figures 2 (b) and 4 (b), and the wave absorbing performance of the polypyrrole fiber doped with the triazophosphoric acid is obviously superior to that of the polypyrrole fiber doped with the polystyrene sulfonic acid under the test frequency band of 2-18 GHz.

Comparative example 2: similar to example 1, but the molar amount of doped triazophos was changed to acetic acid. Finally obtaining the acetic acid doped polypyrrole nanometer material, wherein the micro-morphology of the material is shown in figure 5.

The nano-fiber accounting for 10 percent of the total mass of the composite material is uniformly mixed with paraffin, and the mixture is pressed into an annular die (the height is 2.0 mm, the outer diameter is 7.0 mm, and the inner diameter is 3.0 mm) to prepare a sample, and according to the test of a vector network analyzer, the dielectric constant and the wave absorbing performance of the sample are shown in the attached figure 6.

Compared with the nanofiber prepared in the example 1, the polypyrrole nanofiber prepared in the comparative example 1 is longer in comparison with the nanofiber prepared in the example 1 in the aspect of morphological characteristics, such as the graph shown in FIGS. 1 and 5, due to different types of doped acids; the dielectric constants of the two are shown in fig. 2 (a) and 6 (a), and compared with the polypyrrole nano-fibers of example 1, the polypyrrole nano-fibers have higher dielectric properties. The wave absorbing properties of the fiber and the fiber are shown in figures 2 (b) and 6 (b), under a test frequency band of 2-18 GHz, the wave absorbing property of the polypyrrole fiber doped with the triazophos has a strong electromagnetic wave absorption peak (-46 dB) under a low test thickness (2 mm), and when the test thickness of the polypyrrole nanofiber doped with acetic acid is 5 mm, the strong electromagnetic wave absorption peak only reaches-37 dB. The effective wave-absorbing bandwidths of the two are respectively about 5.6 GHz and 5.5 GHz. Therefore, the polypyrrole nano-fiber doped with the triazophosphoric acid has more excellent wave absorbing performance.

Comparative example 3: similar to example 1, but without any addition of acid. Finally obtaining the undoped chiral spiral hollow structure polypyrrole nano-fiber, wherein the micro-morphology of the polypyrrole nano-fiber is shown in figure 7.

Mixing with paraffin according to the ratio of nanofiber accounting for 10% of the total mass of the composite material, pressing into an annular mold (height 2.0 mm, outer diameter 7.0 mm, inner diameter 3.0 mm) to obtain a sample, and testing with a vector network analyzer to obtain the dielectric constant and wave absorbing performance shown in figure 8.

The nanofibers prepared in this comparative example are longer in comparison to example 1 from the topographical features, as shown in fig. 1 and 4, in example 4 because example 4 is not doped with any acid; the dielectric constants of the polypyrrole nano-fiber and the polypyrrole nano-fiber are shown in fig. 2 (a) and 8 (a), the dielectric constant of the polypyrrole nano-fiber with the triazophosphoric acid doped chiral hollow structure is higher in a high-frequency (8-18 GHz) test environment, and compared with the polypyrrole nano-fiber and the polypyrrole nano-fiber, the polypyrrole nano-fiber in the embodiment 1 has higher dielectric properties as a whole. The wave absorbing properties of the fiber and the fiber are shown in figures 2 (b) and 8 (b), under a test frequency band of 2-18 GHz, the wave absorbing property of the polypyrrole fiber doped with the triazophos pentaphosphoric acid has a strong electromagnetic wave absorption peak (46 dB) under a low test thickness (2 mm), and when the test thickness of the polypyrrole nanofiber is 2 mm, the strong electromagnetic wave absorption peak only reaches 26.5 dB. The effective wave absorbing bandwidth of the two is about 5.6 GHz. Therefore, the polypyrrole nano-fiber doped with the triazophosphoric acid has more excellent wave absorbing performance.

Claims

1. The polypyrrole nano-fiber material doped with the triazophosphoric acid is characterized in that the nano-fiber material is doped with the triazophosphoric acid, and the nano-fiber material has a chiral spiral hollow structure;

the preparation method comprises the following steps:

step 1: dispersing a chiral inducing reagent and a pyrrole monomer in a certain volume of methanol according to a molar ratio of 1:40, adding water with the volume 5 times that of the methanol, stirring for a period of time, then dripping triazophosphoric acid with the molar amount 50 times that of the chiral inducing reagent, stirring for a period of time to form a uniformly dispersed solution, and carrying out ice bath, wherein the mass concentration of the pyrrole monomer is 2.20-2.50 g/L;

step 2: dropping ammonium persulfate in a molar amount 40 times that of the chiral induction reagent into the uniformly dispersed solution in the ice bath in the step 1, and stirring for a period of time;

2. The nanofiber material of claim 1, wherein the nanofiber material has excellent wave absorbing properties, and has an absorption peak of-47 dB at a test thickness of 2 mm.

3. A method for preparing a nanofibrous material according to claim 1 or 2, characterised in that it comprises the following steps:

4. The method of claim 3, wherein in step 3, the drying temperature is not greater than 60 ℃.

5. A wave-absorbing material, characterized in that the wave-absorbing material contains the nanofiber material of claim 1.