阅读说明：本技术 一种团簇状磁性聚苯胺超细纳米纤维及其制备方法、应用 (Cluster-shaped magnetic polyaniline superfine nanofiber and preparation method and application thereof ) 是由 陶玉仑 李硕 李大为 于 2021-08-02 设计创作，主要内容包括：本发明公开了一种团簇状磁性聚苯胺超细纳米纤维的制备方法,包括如下步骤：在苯胺中浸泡纳米磁性粉体,然后与酸性物质的溶液混匀,加入引发剂,反应共聚得到团簇状磁性聚苯胺超细纳米纤维。本发明还公开了一种团簇状磁性聚苯胺超细纳米纤维,按照上述团簇状磁性聚苯胺超细纳米纤维的制备方法制得。本发明还公开了上述团簇状磁性聚苯胺超细纳米纤维在吸附重金属、有机染料中的应用。本发明所述团簇状磁性聚苯胺纳米纤维,其直径很小,形貌可控,方法简单,并且具有良好的吸附性能。(The invention discloses a preparation method of cluster-shaped magnetic polyaniline superfine nano-fiber, which comprises the following steps: soaking the nano magnetic powder in aniline, then uniformly mixing with the solution of acidic substances, adding an initiator, and carrying out reaction copolymerization to obtain the cluster-shaped magnetic polyaniline superfine nanofiber. The invention also discloses cluster-shaped magnetic polyaniline superfine nano-fiber which is prepared by the preparation method of the cluster-shaped magnetic polyaniline superfine nano-fiber. The invention also discloses application of the cluster magnetic polyaniline superfine nanofiber in adsorption of heavy metals and organic dyes. The cluster magnetic polyaniline nanofiber disclosed by the invention is small in diameter, controllable in appearance, simple in method and good in adsorption performance.)

1. A method for preparing cluster-shaped magnetic polyaniline superfine nano-fiber is characterized by comprising the following steps: soaking the nano magnetic powder in aniline, then uniformly mixing with the solution of acidic substances, adding an initiator, and carrying out reaction copolymerization to obtain the cluster-shaped magnetic polyaniline superfine nanofiber.

2. The method for preparing the clustered magnetic polyaniline ultrafine nanofiber as claimed in claim 1, wherein the soaking time is 1-8 h.

3. The method for preparing the cluster-shaped magnetic polyaniline ultrafine nanofiber as claimed in claim 1 or 2, wherein the addition speed of the initiator is 1.2-1.6 g/min.

4. The method for preparing the cluster-like magnetic polyaniline ultrafine nanofiber as claimed in any one of claims 1 to 3, wherein the acidic substance comprises: at least one of p-toluenesulfonic acid, camphorsulfonic acid, hydrochloric acid, sulfuric acid and nitric acid.

5. The method for preparing the clustered magnetic polyaniline ultrafine nanofiber as claimed in any one of claims 1 to 4, wherein the initiator comprises: at least one of ammonium persulfate, sodium persulfate and potassium persulfate.

6. The method for preparing the cluster-shaped magnetic polyaniline ultrafine nanofiber as claimed in any one of claims 1 to 5, wherein the reaction temperature is-30 to 60 ℃ and the reaction time is 8 to 12 hours.

7. The method for preparing the clustered magnetic polyaniline ultrafine nanofiber as claimed in any one of claims 1 to 6, wherein the weight ratio of the nano magnetic powder to the aniline is 1-5: 10.

8. The method for preparing the cluster-shaped magnetic polyaniline ultrafine nanofiber as claimed in any one of claims 1 to 7, wherein the weight ratio of aniline, acidic substance and initiator is 1-10:1-10: 1-100.

9. A cluster-shaped magnetic polyaniline ultrafine nanofiber, which is characterized by being prepared by the method for preparing the cluster-shaped magnetic polyaniline ultrafine nanofiber according to any one of claims 1 to 8.

10. The application of the cluster-shaped magnetic polyaniline ultrafine nanofiber as claimed in claim 9 in adsorption of heavy metals and organic dyes; preferably, the heavy metal is nickel; preferably, the organic dye is congo red or rhodamine-B.

Technical Field

The invention relates to the technical field of polyaniline, in particular to a cluster-shaped magnetic polyaniline superfine nanofiber and a preparation method and application thereof.

Background

Polyaniline is the most valuable substance in the field of conductive polymers. It has not only conductivity and metal processing property, but also high conductivity. It also has chemical and electrochemical properties not found in metals and plastics. The material can be widely applied to the fields of electronic chemical industry, shipbuilding, petrifaction, national defense and the like, has high added value, wide application range and huge commercial opportunity, and is one of the most popular materials in the global research and development war.

Magnetic polyaniline is a polymeric compound with special electrical and optical properties and can have post-doping and electrochemical properties after doping. The synthesis of magnetic polyaniline includes chemical polymerization and electrochemical polymerization. At present, the preparation of magnetic polyaniline is widely reported, and the most common method for synthesizing the magnetic polyaniline nanocomposite is chemical oxidative polymerization. For example, Marili, research and development on polyaniline doping [ J ], Shandong chemical engineering, 2017,46(01):65-67, discloses that in the presence of ferroferric oxide nanoparticles and a surfactant, aniline monomers are polymerized in situ to obtain a polyaniline/nano ferroferric oxide core-shell structure composite material. There are also reports on the literature of methods for synthesizing polyaniline/ferroferric oxide nanoparticles with good dispersion, and the like.

However, the magnetic polyaniline prepared at present has various and uncontrollable morphologies, and is mostly shell-core particles, and the conductivity, adsorption and other properties of the magnetic polyaniline are affected by the different morphologies. At present, a simple and effective method for controlling the appearance of the polyaniline/nanoparticle composite material still has scientific challenges.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a cluster-shaped magnetic polyaniline ultrafine nanofiber as well as a preparation method and application thereof.

The invention provides a preparation method of cluster-shaped magnetic polyaniline superfine nano-fiber, which comprises the following steps: soaking the nano magnetic powder in aniline, then uniformly mixing with the solution of acidic substances, adding an initiator, and carrying out reaction copolymerization to obtain the cluster-shaped magnetic polyaniline superfine nanofiber.

After the reaction copolymerization, solid-liquid separation is carried out, the solid is washed by warm water and ethanol in sequence, and then the cluster-shaped magnetic polyaniline ultrafine nano fiber is obtained after drying.

The nano magnetic powder is nano iron tetroxide.

Preferably, soaking for 1-8 h.

Preferably, the rate of addition of the initiator is from 1.2 to 1.6 g/min.

The above initiator may be added in the form of an aqueous solution, the concentration of the aqueous initiator solution being preferably 0.25 g/ml.

The concentration of the solution of the acidic substance is preferably 0.01 to 0.1g/ml, and the solvent of the solution of the acidic substance is preferably water.

Preferably, the acidic substance comprises: at least one of p-toluenesulfonic acid, camphorsulfonic acid, hydrochloric acid, sulfuric acid and nitric acid.

Preferably, the initiator comprises: at least one of ammonium persulfate, sodium persulfate and potassium persulfate.

Preferably, the reaction temperature is-30-60 ℃, and the reaction time is 8-12 h.

Preferably, the weight ratio of the nano magnetic powder to the aniline is 1-5: 10.

Preferably, the weight ratio of the aniline to the acidic substance to the initiator is 1-10:1-10: 1-100.

The water is deionized water.

The invention also provides cluster-shaped magnetic polyaniline superfine nano-fiber which is prepared by the preparation method of the cluster-shaped magnetic polyaniline superfine nano-fiber.

The invention also provides the application of the cluster magnetic polyaniline superfine nanofiber in adsorbing heavy metals and organic dyes.

Preferably, the heavy metal is nickel.

Preferably, the organic dye is congo red or rhodamine-B.

Has the advantages that:

the invention selects a proper method to prepare the shape-controllable magnetic polyaniline superfine nanofiber (the diameter is less than 60nm, the length is about 2 mu m), and the superfine nanofiber is combined to form a cluster-shaped structure; the superfine nano fiber has larger specific surface area, and has better adsorption and constraint performance on ions/substances than a crude fiber or a shell-core structure, and in addition, the superfine nano fiber forms a cluster-shaped structure which has a cage-shaped structure and can lock organic matters and metal ions; the cluster magnetic polyaniline superfine nano-fiber has good adsorption performance by combining the superfine nano-fiber and the cluster structure; the magnetic adsorption material can be used for adsorbing metal ions and organic dyes in sewage, and has the advantages of magnetic property and easy recovery; in addition, the preparation method is simple, and the shape of the obtained magnetic polyaniline is controllable.

Drawings

FIG. 1 is a scanning electron microscope image of the clustered magnetic polyaniline ultrafine nanofiber prepared in example 1.

FIG. 2 is a partial enlarged view of a scanning electron microscope image of the clustered magnetic polyaniline ultrafine nanofiber prepared in example 1.

FIG. 3 is an infrared spectrum of the cluster-shaped magnetic polyaniline ultrafine nanofibers prepared in examples 1-4, wherein 10:1 is example 1, 10:2 is example 2, 10:3 is example 3, and 10:4 is example 4.

Fig. 4 is a graph showing the absorbance of the nickel chloride stock solution and the filtrate before and after the adsorption of the cluster-like magnetic polyaniline ultrafine nanofibers prepared in example 1.

FIG. 5 shows the result of the removal rate of nickel ions by the cluster-shaped magnetic polyaniline ultrafine nanofiber at different pH values.

Fig. 6 shows the result of the removal rate of nickel ions by the cluster-shaped magnetic polyaniline ultrafine nanofibers at different nickel ion concentrations.

FIG. 7 shows the results of the removal rate of Congo red by the cluster-shaped magnetic polyaniline ultrafine nanofibers at different temperatures.

FIG. 8 shows the result of the removal rate of rhodamine-B by the cluster-shaped magnetic polyaniline ultrafine nanofiber at different temperatures.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.

Example 1

A method for preparing cluster-shaped magnetic polyaniline superfine nano-fiber comprises the following steps:

mixing 100ml of aniline with 10g of nano ferroferric oxide powder, uniformly stirring by magnetic force, and then soaking for 3 hours to mark as a solution A;

preparing a proper reaction container, filling 5000ml of water in the container, placing an ice bag on the periphery of the outer bottom of the container (in order to prevent the reaction from generating heat and bumping, proper temperature reduction is needed), then adding 300ml of aqueous solution containing 100g of p-toluenesulfonic acid into the container, opening an electric stirring rod, and starting stirring; then adding the solution A and mixing uniformly;

then dropwise adding 1000ml of ammonium persulfate aqueous solution with the concentration of 0.25g/ml (controlling the adding speed of the ammonium persulfate to be 1.4g/min, and finishing dropwise adding within about 3 h); keeping the temperature at 10 ℃, continuously stirring for 10h, performing suction filtration, washing the solid with warm water at 60 ℃ until the filtrate turns from dark yellow to colorless, then washing the solid with ethanol to remove p-toluenesulfonic acid, and drying in an oven at 60 ℃ to obtain the cluster-shaped magnetic polyaniline ultrafine nanofiber.

Example 2

The amount of the nano ferroferric oxide powder is 20g, and the rest is the same as that of the embodiment 1.

Example 3

The amount of the nano ferroferric oxide powder is 30g, and the rest is the same as that of the embodiment 1.

Example 4

The amount of the nano ferroferric oxide powder is 40g, and the rest is the same as that of the embodiment 1.

Example 5

The amount of the nano ferroferric oxide powder is 50g, and the rest is the same as that of the embodiment 1.

Example 6

A method for preparing cluster-shaped magnetic polyaniline superfine nano-fiber comprises the following steps:

mixing 100ml of aniline with 30g of nano ferroferric oxide powder, uniformly stirring by magnetic force, and then soaking for 1 hour to mark as a solution A;

preparing a proper reaction container, filling 5000ml of water in the container, placing an ice bag on the periphery of the outer bottom of the container (in order to prevent the reaction from generating explosive boiling due to heat release, proper temperature reduction is needed), adding 300ml of an aqueous solution containing 100g of camphorsulfonic acid into the container, opening an electric stirring rod, and starting stirring; then adding the solution A and mixing uniformly;

then 1000ml of sodium persulfate aqueous solution with the concentration of 1g/ml is dripped (the addition speed of the sodium persulfate is controlled to be 1.2 g/min); keeping the temperature at minus 30 ℃, continuously stirring for 12h, carrying out suction filtration, washing the solid with warm water at 60 ℃ until the filtrate turns from dark yellow to colorless, then washing the solid with ethanol to remove p-toluenesulfonic acid, and drying in an oven at 60 ℃ to obtain the cluster-shaped magnetic polyaniline ultrafine nanofiber.

Example 7

A method for preparing cluster-shaped magnetic polyaniline superfine nano-fiber comprises the following steps:

mixing 100ml of aniline with 20g of nano ferroferric oxide powder, uniformly stirring by magnetic force, and then soaking for 8 hours to mark as a solution A;

preparing a proper reaction container, filling 5000ml of water in the container, placing an ice bag (which needs to be properly cooled in order to prevent the reaction from generating heat and bumping) at the periphery of the outer bottom of the container, adding 300ml of aqueous solution containing 100g of hydrochloric acid (the mass fraction of HCl in the hydrochloric acid is 5 wt%) into the container, opening an electric stirring rod, and starting stirring; then adding the solution A and mixing uniformly;

then 1000ml of potassium persulfate aqueous solution with the concentration of 0.1g/ml is dripped (the addition speed of the potassium persulfate is controlled to be 1.6 g/min); keeping the temperature at 60 ℃, continuously stirring for 8h, performing suction filtration, washing the solid with warm water at 60 ℃ until the filtrate turns from dark yellow to colorless, then washing the solid with ethanol to remove p-toluenesulfonic acid, and drying in an oven at 60 ℃ to obtain the cluster-shaped magnetic polyaniline ultrafine nanofiber.

Experiment 1

The cluster-like magnetic polyaniline ultrafine nanofibers prepared in example 1 were examined, and the results are shown in fig. 1-2.

FIG. 1 is a scanning electron microscope image of the clustered magnetic polyaniline ultrafine nanofiber prepared in example 1; FIG. 2 is a partial enlarged view of a scanning electron microscope image of the clustered magnetic polyaniline ultrafine nanofiber prepared in example 1.

As can be seen from the figures 1-2, the magnetic polyaniline ultrafine nano-fiber prepared by the invention forms a cluster structure in a combined manner, has a cage structure, has a diameter less than 60nm, has a diameter even reaching 30nm, and is very fine.

Experiment 2

The cluster-shaped magnetic polyaniline ultrafine nanofibers prepared in examples 1 to 4 were examined, and the results are shown in fig. 3; FIG. 3 is an infrared spectrum of the cluster-shaped magnetic polyaniline ultrafine nanofibers prepared in examples 1-4, wherein 10:1 is example 1, 10:2 is example 2, 10:3 is example 3, and 10:4 is example 4.

As can be seen from fig. 3, the ferriferrous oxide doped polyaniline has 5 absorption peaks, and each peak has its corresponding group. Refer to the relevant reference for information, 1569.4cm^-1And 1487.0cm^-1The absorption peak at (A) is a characteristic peak of the benzene ring. Comparing the infrared absorption spectrum with that of the intrinsic polyaniline, we find that the wave number of the position of the diffraction peak of the doped polyaniline is reduced, namely the so-called blue shift occurs, and the analysis reason is that a conjugated structure occurs because part of the doped polyaniline is oxidized, the electron cloud density is reduced, and the blue shift occurs. Tetraoxidation ofThe characteristic peak of the ferroferric oxide nano composite material comprises 3449cm^-1The peak at (1) is composed of carboxyl and hydroxyl, and is at 1608cm^-1Indicating that the carbonyl is a carbon-shell magnetite core formed by oxidation of glucose. In 559cm^-1The vibration band at (b) follows the Fe ═ O bond. For polyaniline ferroferric oxide nano composite material, except Fe₃O₄The characteristic peak of the nano composite material is outside 3208cm^-1Is formed by the stretching vibration of polyaniline and is 1565cm^-1C stretching vibration from quinone ring at 1490cm^-1Is due to a benzene ring vibrating telescopically, 1294cm^-1N stretching vibration and 1128cm of benzene ring^-1(C ═ H) caused by contraction shock. The infrared spectrogram can basically confirm that the cluster-shaped magnetic polyaniline superfine nano-fiber prepared by the invention has corresponding groups, and the success of the experiment is proved.

Experiment 3

50g of each of the cluster-shaped magnetic polyaniline ultrafine nanofibers prepared in examples 1 to 5 was ground into fine powders using a mortar; and selecting a magnet with proper magnetic force, respectively carrying out adsorption test on each group of powder, and judging the magnetic force of each group by calculating the adsorption quantity of each group of powder. The results are shown in Table 1.

TABLE 1 magnetic assay results

Grouping	Example 1	Example 2	Example 3	Example 4	Example 5
						Adsorption capacity (g)	6.0356	11.7943	17.8547	20.4063	23.3004
Adsorption Rate (%)	12.0712	23.5886	35.7094	40.8126	46.6008

As can be seen from Table 1, with the continuous addition of ferroferric oxide, the magnetic force of the prepared cluster-shaped magnetic polyaniline ultrafine nano fiber is continuously enhanced.

Experiment 4

The cluster-shaped magnetic polyaniline ultrafine nanofiber prepared in the example 1 is taken, and the adsorption performance of the nanofiber on heavy metal Ni is detected; the specific detection method comprises the following steps:

(1) the testing process comprises the following steps: preparing nickel ion standard solutions with different concentrations of 2.00g/l, 2.50g/l, 3.33g/l, 5.00g/l and 10.00g/l respectively. The method comprises the steps of adsorbing nickel ions by a column passing method under the condition that the mass of cluster-shaped magnetic polyaniline superfine nano fibers is certain and the volume of a solution is certain, fully contacting the solution with an adsorbent under atmospheric pressure and filtering, taking filtrate to measure the maximum absorbance of the filtrate and carrying out linear fitting on the relationship between absorbance and concentration to obtain the fitting formula of the absorbance and the concentration of the nickel ions at the position of the maximum absorbance wavelength of the nickel ions of 394nm, wherein y is the absorbance, and x is the concentration of the nickel ions and g/l.

(2) Calculating the adsorption amount: chamberPreparing 100ml of nickel chloride solution with a certain concentration at the room temperature, adsorbing 20g of cluster-shaped magnetic polyaniline ultrafine nano-fiber prepared in the example 1 under the condition that the pH is neutral, detecting the absorbance of stock solution and filtrate, and calculating the concentration C of nickel ions in the stock solution by using a fitting formula in the step (1)₀And the concentration C of nickel ions in the filtrate_eThe adsorption quantity Q is calculated by a formula_e＝(C₀-C_e) V/M, wherein V is the volume of the nickel chloride solution, and M is the mass of the adsorbent; removal rate R ═ C₀-C_e)/C₀*100％。

Referring to fig. 4, fig. 4 is a graph showing the absorbance of the nickel chloride stock solution and the filtrate before and after the adsorption of the cluster-like magnetic polyaniline ultrafine nanofibers prepared in example 1.

As can be seen from FIG. 4, the absorbance of the raw solution and the filtrate at 394nm was 0.5831 and 0.0343, respectively. The concentration before and after filtration is 23.6922g/l and 1.5275g/l respectively by substituting into a fitting formula, the removal rate is 93.55 percent by calculation, and the once filtration adsorption capacity reaches 110 mg/g.

Taking the cluster-shaped magnetic polyaniline ultrafine nanofiber prepared in the example 1, adjusting the pH value with 1mol/l hydrochloric acid according to the method of the steps (1) to (2), and inspecting the removal rate of the cluster-shaped magnetic polyaniline ultrafine nanofiber on nickel ions at different pH values; the results are shown in FIG. 5; FIG. 5 shows the result of the removal rate of nickel ions by the cluster-shaped magnetic polyaniline ultrafine nanofiber at different pH values.

As can be seen from fig. 5, the removal rate reached 93.82% at PH 4. Therefore, the cluster magnetic polyaniline superfine nano-fiber has the best effect of adsorbing nickel ions in a weak acid environment. The probable reason is that under the acidic condition, more hydrogen ions exist, ammonium nitrite ions in the cluster-shaped magnetic polyaniline superfine nano-fiber are easily protonated to form ammonium ions with positive points, and the ammonium ions and metal cations have electrostatic repulsive force, so that the removal rate is reduced, under the weakly acidic condition, deprotonation of the ammonium ions with less hydrogen ion content enhances the removal rate of the complexation reaction with the metal cations to be increased, and under the alkaline condition, alkalide precipitates are easily formed to reduce the removal rate, so that adsorption is facilitated under the weakly acidic condition.

Taking the cluster-shaped magnetic polyaniline ultrafine nanofiber prepared in the example 1, and observing the removal rate of the cluster-shaped magnetic polyaniline ultrafine nanofiber on nickel ions at different nickel ion concentrations (pH is 4) according to the methods in the steps (1) to (2); referring to fig. 6, fig. 6 shows the removal rate of nickel ions from the cluster-like magnetic polyaniline ultrafine nanofibers at different nickel ion concentrations.

From fig. 6, it is understood that in the case of a certain mass of the cluster-like magnetic polyaniline ultrafine nanofibers, the removal rate increases with the increase of the initial concentration of nickel ions, the initial concentration of nickel ions is from 15g/l to 20g/l, and the removal rate rapidly increases from 78.27% to 91.78%, because the available adsorption sites are in sufficient contact with the ions, and the change of the removal rate is small due to the decrease of the effective adsorption sites.

Taking the cluster-shaped magnetic polyaniline ultrafine nanofibers prepared in the example 1, and according to the method of the steps (1) to (2), observing the removal rate of the cluster-shaped magnetic polyaniline ultrafine nanofibers on nickel ions at different temperatures (the pH values are all 4, the concentration of nickel chloride solution is the same, and the using amount of the cluster-shaped magnetic polyaniline ultrafine nanofibers is the same); the results are shown in Table 2.

TABLE 2 removal rate of nickel ions by the cluster-shaped magnetic polyaniline ultrafine nanofiber at different temperatures

As can be seen from Table 2, the removal rate of the cluster-shaped magnetic polyaniline ultrafine nanofiber to nickel ions reaches 90-94% at 30-70 ℃.

Experiment 5

Taking the cluster-shaped magnetic polyaniline superfine nanofiber prepared in the embodiment 1, and detecting the adsorption performance of the nanofiber on organic dye Congo red; the specific detection method comprises the following steps:

(1) the testing process comprises the following steps: congo red solutions with certain concentrations are prepared, and the concentrations are respectively 50mg/l, 25mg/l, 12.5mg/l, 10mg/l, 8.33mg/l and 5 mg/l. And respectively measuring the ultraviolet absorption peaks of Congo red solutions with different concentrations, judging the wavelength of the peak value, and performing linear fitting on the concentration and the absorbance to find out a fitting relational expression. At the wavelength 498nm of the maximum absorbance of the congo red, the fitting formula of the absorbance and the concentration of the congo red is that y is 0.01919x +0.00508, y is the absorbance, and x is the concentration of the congo red in mg/l.

(2) 50ml of 10mg/l Congo red solution is prepared, the absorption test is respectively carried out on cluster-shaped magnetic polyaniline ultrafine nanofibers with the mass of 0.01, 0.02, 0.03, 0.04 and 0.05g, the magnetic stirring is carried out for 30min under the condition of fixed rotating speed, the supernatant is centrifuged, the absorbance at 498nm is measured, and the concentration is calculated, and the result is shown in Table 3.

TABLE 3 Mass and absorbance of different cluster-like magnetic polyaniline ultrafine nanofibers

As can be seen from table 3, as the mass of the cluster-shaped magnetic polyaniline ultrafine nanofibers increases, the removal rate increases first and then decreases, and when the mass of the cluster-shaped magnetic polyaniline ultrafine nanofibers is 0.03g, the removal rate reaches 99.15% at the maximum, which is probably because the removal rate increases in the first half section along with the increase in the mass of the cluster-shaped magnetic polyaniline ultrafine nanofibers and the decrease in the removal rate in the latter section is probably caused by the agglomeration of the adsorption sites.

50ml of 10mg/l Congo red solution is prepared, the mass of the cluster-shaped magnetic polyaniline superfine nano-fiber prepared in the example 1 is fixed to be 0.03g, the temperature is 20, 40, 60, 80 and 100 ℃ respectively as variable, stirring and adsorbing are carried out in a constant-temperature water bath kettle for 20min, then centrifugation is carried out, supernatant liquid is obtained, the absorbance is measured, and the concentration and the removal rate are calculated, and the result is shown in figure 7; FIG. 7 shows the results of the removal rate of Congo red by the cluster-shaped magnetic polyaniline ultrafine nanofibers at different temperatures.

As can be seen from fig. 7, the absorption of congo red by the cluster-shaped magnetic polyaniline ultrafine nano fiber is affected by temperature, the higher the temperature is, the higher the removal rate is, so that the absorption is a heat absorption process, and the increase of temperature is beneficial to the absorption process.

Experiment 6

The cluster-shaped magnetic polyaniline superfine nanofiber prepared in the embodiment 1 is taken, and the adsorption performance of the nanofiber on organic dye rhodamine-B is detected; the specific detection method comprises the following steps:

(1) the testing process comprises the following steps: preparing rhodamine-B solutions with certain concentrations of 20mg/l, 30mg/l, 35mg/l, 40mg/l and 50mg/l respectively, measuring ultraviolet absorption peaks of the rhodamine-B solutions with different concentrations respectively, judging the wavelength of the peak value, and performing linear fitting on the concentrations and the absorbance to find out a fitting relation. At the maximum absorbance wavelength 554nm of rhodamine-B, the fitting formula of the absorbance and the concentration of the rhodamine-B is that y is 2.54831x +0.01077, y is the absorbance, and x is the concentration of the rhodamine-B and mg/l.

(2) 50ml of 10mg/l rhodamine-B solution is prepared, the adsorption test is respectively carried out on cluster-shaped magnetic polyaniline ultrafine nanofibers with the mass of 0.01, 0.02, 0.03, 0.04 and 0.05g, the magnetic stirring is carried out for 30min under the condition of fixed rotating speed, the supernatant is centrifuged, the absorbance at 554nm is measured, and the concentration is calculated, as shown in Table 4.

TABLE 4 Mass of different cluster-like magnetic polyaniline ultrafine nanofibers, corresponding absorbance

As can be seen from table 4, as the mass of the cluster-shaped magnetic polyaniline ultrafine nanofibers increases, the removal rate increases first and then decreases, and when the mass of the cluster-shaped magnetic polyaniline ultrafine nanofibers is 0.04g, the removal rate reaches 96.05% at the maximum, which is probably because the removal rate increases in the first half section along with the increase in the mass of the cluster-shaped magnetic polyaniline ultrafine nanofibers, and the decrease in the removal rate may be caused by the agglomeration of the adsorption sites.

50ml of 10mg/l rhodamine-B solution is prepared, the mass of the cluster-shaped magnetic polyaniline superfine nano-fiber prepared in the example 1 is fixed to be 0.04g, the temperature is 20, 40, 60, 80 and 100 ℃ respectively as variable, stirring and adsorbing are carried out in a constant-temperature water bath kettle for 20min, then centrifugation is carried out, supernatant liquid is obtained, absorbance is measured, and the concentration and the removal rate are calculated, and the result is shown in a figure 8; FIG. 8 shows the result of the removal rate of rhodamine-B by the cluster-shaped magnetic polyaniline ultrafine nanofiber at different temperatures.

As can be seen from FIG. 8, the adsorption of the organic dye rhodamine-B by the cluster-shaped magnetic polyaniline ultrafine nanofiber is influenced by temperature, the higher the temperature is, the higher the removal rate is, and therefore the adsorption is a heat absorption process, and the adsorption process is facilitated by raising the temperature.

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.