Raffinate acid doped polyaniline derived carbon / polyaniline composite material as well as preparation method and application thereof

Abstract

The invention discloses a raffinate acid doped polyaniline derived carbon / polyaniline composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: uniformly stirring and mixing raffinate acid, methyl orange, aniline and an oxidizing agent, carrying out an in-situ polymerization reaction to obtain raffinate acid doped polyaniline, carrying out high-temperature calcination to obtain a raffinate acid doped polyaniline derived carbon material, soaking and washing the raffinate acid doped polyaniline derived carbon material with diluted hydrochloric acid, drying, and adding the dried raffinate acid doped polyaniline derived carbon material into an aniline polymerization system to obtain the polyaniline derivative carbon material. And reacting to obtain the raffinate acid doped polyaniline derived carbon / polyaniline composite material. The composite material obtained by the invention is simple in preparation process, does not need to be subjected to impurity removal treatment on the raffinate acid, saves the cost and is beneficial to effective utilization of the raffinate acid. The raffinate acid-doped polyaniline carbon-derived carbon in the composite material has a multi-element doping characteristic, and constructs an efficient conductive network with polyaniline to provide a path for free electrons in the composite material and enhance conduction loss, so that improvement of the electromagnetic wave absorption performance is facilitated, and the raffinate acid-doped polyaniline carbon-derived carbon can be used as an electromagnetic wave absorption material.

Description

Technical Field

[0001] The present invention relates to the field of microwave absorbing materials, and particularly to a raffinate acid-doped polyaniline-derived carbon / polyaniline composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Phosphoric acid is an extremely important raw material acid in the modern chemical industry. With the breakthrough of the wet-process phosphoric acid production process, the production of phosphoric acid from medium and low-grade phosphate rock in China has developed greatly. However, with the development of the phosphorus chemical industry, the output of slag acid and raffinate acid generated during the purification process of wet-process phosphoric acid production is increasing day by day. The raffinate acid contains nearly 50% of P2O5, and impurity metal ions are also concentrated therein. For the use of raffinate acid, currently, it is mainly to mix the raffinate acid with purified wet-process phosphoric acid to prepare low-value chemical products such as monoammonium phosphate, diammonium phosphate, calcium hydrogen phosphate, and potassium dihydrogen phosphate, and its utilization rate has a certain upper limit. Realizing the efficient and incremental utilization of raffinate acid has become one of the urgent problems faced by the healthy development of the phosphorus chemical industry.

[0003] On the other hand, the development of electronic information technology has brought major technological progress, but it has also led to an increase in electromagnetic wave pollution. The adverse effects of electromagnetic wave radiation are mainly reflected in the mutual electromagnetic interference and electromagnetic leakage between electronic devices, as well as serious health hazards to humans. To solve these problems, extensive and in-depth exploration has been carried out on electromagnetic wave absorbing materials with advantages in mass, absorption bandwidth, and strength. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems existing in the efficient utilization of raffinate acid and electromagnetic wave absorbing materials. The present invention provides a raffinate acid-doped polyaniline-derived carbon / polyaniline composite material, a preparation method thereof, and an application thereof.

[0005] To achieve the above purpose, on the one hand, the present invention provides a preparation method of a raffinate acid-doped polyaniline-derived carbon / polyaniline composite material, which includes the following steps:

[0006] 1) Adding raffinate acid and methyl orange to a polymerization system composed of aniline and an oxidant, mixing evenly, and carrying out an in-situ polymerization reaction to obtain raffinate acid-doped polyaniline.

[0007] 2) Calcining the raffinate acid-doped polyaniline at a high temperature to obtain a raffinate acid-doped polyaniline-derived carbon material, wherein the role of high-temperature calcination is to burn the synthesized polyaniline and the residual organic extractant in the raffinate acid into carbon.

[0008] 3) Performing pickling treatment on the raffinate acid-doped polyaniline-derived carbon material, filtering and drying to obtain a pickled derived carbon material, wherein pickling is to remove metal impurities by turning them into metal ions.

[0009] 4) Add the pickled derivative carbon material into the polymerization system composed of aniline and an oxidant, and conduct in-situ polymerization again to obtain a raffinate acid-doped polyaniline carbon derivative carbon / polyaniline composite material. The in-situ polymerization again is to coat polyaniline on the calcined carbon material, so as to be used for microwave absorption.

[0010] It should be noted here that since the raffinate acid contains metal impurities and organic extractants, it is necessary to purify and remove impurities if the raffinate acid is to be used. And the method of the present invention can directly use the raffinate acid. The phosphoric acid in the raffinate acid can participate in the polymerization reaction of aniline, the functional groups of polyaniline can adsorb the metal impurities in the raffinate acid, and these metals can activate the carbon during subsequent high-temperature treatment.

[0011] The oxidant in the present invention is an oxidant adapted to the chemical oxidative polymerization of aniline. As a further preferred technical solution of the present invention, the oxidant is ammonium persulfate or potassium persulfate.

[0012] As a further preferred technical solution of the present invention, in step 1), the mass ratio of the raffinate acid, oxidant, aniline, and methyl orange is 1:30 - 100:10 - 40:3 - 10.

[0013] As a further preferred technical solution of the present invention, in step 1), the in-situ polymerization reaction is carried out at 0 - 4°C for 12 - 36 h; and / or, in step 4), the in-situ polymerization reaction is carried out at 0 - 4°C for 6 - 16 h.

[0014] As a further preferred technical solution of the present invention, in step 2), the calcination temperature is 800 - 850°C, and the calcination treatment time is 6 - 8 h.

[0015] As a further preferred technical solution of the present invention, in step 3), the raffinate acid-doped polyaniline derivative carbon material is pickled by soaking and ultrasonic treatment with dilute hydrochloric acid, and then filtered and dried after pickling. Further, the concentration of the dilute hydrochloric acid is 1 - 2 mol / L, the mass ratio of the raffinate acid-doped polyaniline derivative carbon material to the dilute hydrochloric acid is 1:10 - 20, and the soaking and ultrasonic treatment time is 2 - 3 h.

[0016] As a further preferred technical solution of the present invention, in step 4), the mass ratio of the pickled derivative carbon material, aniline, and oxidant is 1:5 - 10:15 - 30.

[0017] According to another aspect of the present invention, the present invention also provides a raffinate acid-doped polyaniline derivative carbon / polyaniline composite material.

[0018] According to still another aspect of the present invention, the present invention also provides an application of a raffinate acid-doped polyaniline derivative carbon / polyaniline composite material as an electromagnetic wave absorption material.

[0019] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in the following aspects:

[0020] 1) The preparation process is simple, without excessive treatment of the raffinate acid, and the metal impurities contained in the raffinate acid are effectively utilized, thereby reducing the production cost;

[0021] 2) Phosphoric acid in the raffinate acid interacts with the positively charged polyaniline polymer chain, and the imino functional group of the polyaniline polymer chain effectively adsorbs metal elements, facilitating subsequent phosphorus doping and high-temperature activation;

[0022] 3) Iron in the raffinate acid and methyl orange form a template to facilitate the synthesis of polyaniline, and magnesium and aluminum are beneficial to the high-temperature carbonization of polyaniline;

[0023] 4) The raffinate acid-doped polyaniline carbon-derived carbon in the composite material has the characteristics of multi-element doping, and constructs an efficient conductive network with polyaniline, providing a path for free electrons inside the composite material, enhancing the conduction loss, and improving its electromagnetic wave absorption performance, and can be used as an electromagnetic wave absorption material. Specific Embodiments

[0024] The following details the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0025] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The test reagents used in the following embodiments are all conventional biochemical reagents unless otherwise specified; the experimental methods used are all conventional methods unless otherwise specified.

[0026] Example 1:

[0027] A preparation method of a raffinate acid-doped polyaniline-derived carbon / polyaniline composite material is provided as follows:

[0028] 1) After stirring and mixing the raffinate acid, aniline, methyl orange, and ammonium persulfate, an in-situ polymerization reaction is carried out at 4°C for 24 hours to obtain raffinate acid-doped polyaniline, where the mass ratio of the raffinate acid, ammonium persulfate, aniline, and methyl orange is 1:25:10:3;

[0029] 2) The raffinate acid-doped polyaniline is calcined at 800°C for 8 hours to obtain a raffinate acid-doped polyaniline-derived carbon material;

[0030] 3) The raffinate acid-doped polyaniline-derived carbon material is added to dilute hydrochloric acid, soaked and ultrasonicated, and then filtered and dried to obtain an acid-washed derived carbon material, where the mass ratio of the raffinate acid-doped polyaniline-derived carbon material to dilute hydrochloric acid is 1:10, the concentration of dilute hydrochloric acid is 1 mol / L, and the soaking and ultrasonicating time is 2 hours;

[0031] 4) Add the pickled derivative carbon material to the aniline polymerization system containing aniline and ammonium persulfate, and carry out a secondary in-situ polymerization reaction at 0 °C for 16 h. The mass ratio of the pickled derivative carbon material, aniline, and ammonium persulfate is 1:5:12, and finally a raffinate acid-doped polyaniline carbon derivative carbon / polyaniline composite material is obtained.

[0032] Use a vector network analyzer (Agilent N5230) to conduct coaxial method testing. The minimum reflection loss of the composite material obtained in this example is -50.2 dB, and the effective absorption bandwidth is 5.2 GHz.

[0033] Example 2:

[0034] 1) Stir and mix raffinate acid, aniline, methyl orange, and potassium persulfate, and carry out an in-situ polymerization reaction at 0 °C for 36 h to obtain raffinate acid-doped polyaniline. The mass ratio of raffinate acid, potassium persulfate, aniline, and methyl orange is 1:90:30:10;

[0035] 2) Calcinate the raffinate acid-doped polyaniline at 850 °C for 7 h to obtain a raffinate acid-doped polyaniline derivative carbon material;

[0036] 3) Add the raffinate acid-doped polyaniline derivative carbon material to dilute hydrochloric acid, soak, ultrasonic filter, and dry to obtain a pickled derivative carbon material. The mass ratio of the raffinate acid-doped polyaniline derivative carbon material to dilute hydrochloric acid is 1:20, the concentration of dilute hydrochloric acid is 1 mol / L, and the soaking and ultrasonic time is 3 h;

[0037] 4) Add the pickled derivative carbon material to the aniline polymerization system, and carry out an in-situ polymerization reaction again at 4 °C for 12 h. The mass ratio of the pickled derivative carbon material, aniline, and potassium persulfate is 1:5:18, and finally a raffinate acid-doped polyaniline carbon derivative carbon / polyaniline composite material is obtained.

[0038] Use a vector network analyzer (Agilent N5230) to conduct coaxial method testing. The minimum reflection loss of the composite material obtained in this example is -52.4 dB, and the effective absorption bandwidth is 5.4 GHz.

[0039] Example 3:

[0040] 1) Stir and mix raffinate acid, aniline, methyl orange, and ammonium persulfate, and carry out an in-situ polymerization reaction at 4 °C for 30 h to obtain raffinate acid-doped polyaniline. The mass ratio of raffinate acid, ammonium persulfate, aniline, and methyl orange is 1:50:20:6;

[0041] 2) Calcinate the raffinate acid-doped polyaniline at 800 °C for 8 h to obtain a raffinate acid-doped polyaniline derivative carbon material;

[0042] 3) Add the raffinate acid-doped polyaniline-derived carbon material to dilute hydrochloric acid. After soaking, ultrasonic treatment, filtration, and drying, the pickled derived carbon material is obtained. The mass ratio of the raffinate acid-doped polyaniline-derived carbon material to dilute hydrochloric acid is 1:15, the concentration of dilute hydrochloric acid is 2 mol / L, and the soaking and ultrasonic treatment time is 2 h;

[0043] 4) Add the pickled derived carbon material to the polymerization system of aniline and carry out an in-situ polymerization reaction at 4 °C for 10 h. The mass ratio of the pickled derived carbon material, aniline, and ammonium persulfate is 1:8:20, and finally the raffinate acid-doped polyaniline carbon-derived carbon / polyaniline composite material is obtained.

[0044] Use a vector network analyzer (Agilent N5230) to perform coaxial method testing. The minimum reflection loss of the composite material obtained in this example is -48.4 dB, and the effective absorption bandwidth is 4.8 GHz.

[0045] Example 4:

[0046] 1) Stir and mix the raffinate acid, aniline, methyl orange, and ammonium persulfate, and carry out an in-situ polymerization reaction at 4 °C for 24 h to obtain raffinate acid-doped polyaniline. The mass ratio of the raffinate acid, ammonium persulfate, aniline, and methyl orange is 1:30:15:5;

[0047] 2) Calcinate the raffinate acid-doped polyaniline at 800 °C for 8 h to obtain the raffinate acid-doped polyaniline-derived carbon material;

[0048] 3) Add the raffinate acid-doped polyaniline-derived carbon material to dilute hydrochloric acid. After soaking, ultrasonic treatment, filtration, and drying, the pickled derived carbon material is obtained. The mass ratio of the raffinate acid-doped polyaniline-derived carbon material to dilute hydrochloric acid is 1:10, the concentration of dilute hydrochloric acid is 2 mol / L, and the soaking and ultrasonic treatment time is 3 h;

[0049] 4) Add the pickled derived carbon material to the polymerization system of aniline and carry out an in-situ polymerization reaction at 0 °C for 12 h. The mass ratio of the pickled derived carbon material, aniline, and ammonium persulfate is 1:5:5, and finally the raffinate acid-doped polyaniline carbon-derived carbon / polyaniline composite material is obtained.

[0050] Use a vector network analyzer (Agilent N5230) to perform coaxial method testing. The minimum reflection loss of the composite material obtained in this example is -49.1 dB, and the effective absorption bandwidth is 4.9 GHz.

[0051] Comparative Example 1:

[0052] As a control experiment for Example 2, the difference is that phosphoric acid is used to replace the raffinate acid. The specific method is as follows:

[0053] 1) Stir and mix phosphoric acid, aniline, methyl orange, and potassium persulfate, and conduct an in-situ polymerization reaction at 0 °C for 36 h to obtain phosphoric acid-doped polyaniline, where the mass ratio of phosphoric acid, potassium persulfate, aniline, and methyl orange is 1:90:30:10;

[0054] 2) Calcinate the phosphoric acid-doped polyaniline at 850 °C for 7 h to obtain a phosphoric acid-doped polyaniline-derived carbon material;

[0055] 3) Add the phosphoric acid-doped polyaniline-derived carbon material to dilute hydrochloric acid, soak, ultrasonicate, filter, and dry to obtain an acid-washed derived carbon material, where the mass ratio of the phosphoric acid-doped polyaniline-derived carbon material to dilute hydrochloric acid is 1:20, the concentration of dilute hydrochloric acid is 1 mol / L, and the soaking and ultrasonication time is 3 h;

[0056] 4) Add the acid-washed derived carbon material to the polymerization system of aniline, and conduct an in-situ polymerization reaction again at 4 °C for 12 h, where the mass ratio of the acid-washed derived carbon material, aniline, and potassium persulfate is 1:5:18, and finally obtain a phosphoric acid-doped polyaniline carbon-derived carbon / polyaniline composite material.

[0057] Use a vector network analyzer (Agilent N5230) to conduct coaxial method testing. The minimum reflection loss of the composite material obtained in this example is -42.2 dB, and the effective absorption bandwidth is 4.4 GHz.

[0058] Comparative Example 2:

[0059] As a control experiment for Example 2, the difference is that methyl orange is omitted, and the specific method is as follows:

[0060] 1) Stir and mix raffinate acid, aniline, and potassium persulfate, where the mass ratio of raffinate acid, potassium persulfate, and aniline is 1:90:30. After reacting at 0 °C for 36 h, freeze-dry to obtain sulfuric acid-doped polyaniline;

[0061] 2) Calcinate the raffinate acid-doped polyaniline at 850 °C for 7 h to obtain a raffinate acid-doped polyaniline-derived carbon material;

[0062] 3) Add the raffinate acid-doped polyaniline-derived carbon material to dilute hydrochloric acid, soak, ultrasonicate, filter, and dry to obtain an acid-washed derived carbon material, where the mass ratio of the raffinate acid-doped polyaniline-derived carbon material to dilute hydrochloric acid is 1:20, the concentration of dilute hydrochloric acid is 1 mol / L, and the soaking and ultrasonication time is 3 h;

[0063] 4) Add the acid-washed derived carbon material to the polymerization system of aniline, and conduct an in-situ polymerization reaction again at 4 °C for 12 h, where the mass ratio of the acid-washed derived carbon material, aniline, and potassium persulfate is 1:5:18, and finally obtain a raffinate acid-doped polyaniline carbon-derived carbon / polyaniline composite material.

[0064] The coaxial method test was carried out using a vector network analyzer (Agilent N5230). The minimum reflection loss of the composite material obtained in this embodiment was -45.2 dB, and the effective absorption bandwidth was 4.6 GHz.

[0065] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or modifications can be made to this embodiment without departing from the principle and essence of the present invention. The protection scope of the present invention is only defined by the appended claims.

Claims

1. A method for preparing a raffinate-doped polyaniline-derived carbon / polyaniline composite material, characterized in that: The following steps are involved: 1) adding raffinate and methyl orange into a polymerization system consisting of aniline and an oxidant, mixing them evenly, and performing an in-situ polymerization reaction to obtain raffinate-doped polyaniline; 2) calcining the raffinate-doped polyaniline to obtain a raffinate-doped polyaniline-derived carbon material; 3) acid-washing the raffinate-acid-doped polyaniline-derived carbon material, filtering and drying to obtain an acid-washed derived carbon material; 4) adding the acid-washed derived carbon material into a polymerization system consisting of aniline and an oxidant, and performing an in-situ polymerization reaction again to obtain a raffinate-doped polyaniline carbon-derived carbon / polyaniline composite material.

2. The method for preparing the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 1, characterized in that: The oxidant is ammonium persulfate or potassium persulfate.

3. The method for preparing the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 1, characterized in that: In step 1), the mass ratio of raffinate, oxidant, aniline and methyl orange is 1:30-100:10-40:3-10.

4. The method for preparing the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 1, characterized in that: In step 1), the in-situ polymerization reaction is carried out at 0-4°C for 12-36 hours; and / or, in step 4), the in-situ polymerization reaction is carried out at 0-4°C for 6-16 hours.

5. The method for preparing the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 1, characterized in that: In step 2), the calcination temperature is 800-850° C. and the calcination treatment time is 6-8 hours.

6. The method for preparing the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 1, characterized in that: In step 3), the raffinate-doped polyaniline-derived carbon material is soaked in dilute hydrochloric acid and ultrasonically washed.

7. The method for preparing the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 1, characterized in that: The concentration of dilute hydrochloric acid is 1-2 mol / L, the mass ratio of the raffinate-doped polyaniline-derived carbon material to the dilute hydrochloric acid is 1:10-20, and the ultrasonic immersion time is 2-3 hours.

8. The method for preparing the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 1, characterized in that: In step 4), the mass ratio of the acid-washed derived carbon material, aniline, and oxidant is 1:5-10:15-30.

9. A raffinate-doped polyaniline-derived carbon / polyaniline composite material, characterized in that: The method is prepared by any one of claims 1 to 8.

10. Use of the raffinate-doped polyaniline-derived carbon / polyaniline composite material according to claim 9 as an electromagnetic wave absorbing material.