Porous polyethylene / carbon black composite electrode material, preparation method and application thereof

Abstract

The present application belongs to the technical field of functional electrode material, and particularly relates to a porous polyethylene / carbon black composite electrode material, a preparation method and application thereof. The porous polyethylene / carbon black composite electrode material comprises polyethylene / carbon black composite fibers prepared by melt spinning, and cyclodextrin on the surface of the polyethylene / carbon black composite fibers is crosslinked by a crosslinking agent containing a halogen functional group. The porous polyethylene / carbon black composite fibers are prepared by a melt spinning method, and then are etched by low-temperature plasma technology, and are crosslinked and polymerized with cyclodextrin and a small molecule monomer of the crosslinking agent containing a halogen functional group to prepare the porous polyethylene / carbon black composite electrode material. Compared with the existing electrode material, the porous polyethylene / carbon black composite electrode material prepared by the present application not only has a multi-level pore structure and a higher specific surface area, but also has a variety of active functional group combination sites, and can be used for efficient adsorption and removal of heavy metal ions in industrial wastewater.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of functional electrode materials, and particularly relates to a porous polyethylene / carbon black composite electrode material, a preparation method thereof and application thereof. BACKGROUND

[0002] Carbon black itself has high specific surface area and good electrical conductivity. The carbon black composite electrode material can provide abundant adsorption sites, ensuring that the electrode can effectively transfer electrons during the process of electric adsorption. This helps to maintain the stability of the electric field, allowing the adsorption process to continue efficiently and adsorb more pollutants. Even when dealing with high-concentration wastewater, the electric field strength between the electrodes can be guaranteed, avoiding a decrease in adsorption efficiency due to excessive resistance. In the complex chemical environment of wastewater, the carbon black composite electrode material can remain stable. It can resist corrosion from acids, bases, salts and other chemicals in wastewater, extending the service life of the electrode. Polyethylene as the matrix material gives the composite electrode material certain mechanical properties. By adjusting the type, molecular weight of polyethylene, and the content and dispersion state of carbon black, the mechanical properties of the composite electrode material, such as tensile strength and elongation at break, can be adjusted to some extent to meet the needs of different application scenarios. However, in the actual application process, as the adsorption process progresses, the adsorption sites are gradually occupied, and the adsorption capacity quickly reaches saturation. In addition, it is difficult to achieve efficient and precise adsorption of specific substances in complex mixed systems.

[0003] The porous polyethylene / carbon black composite electrode material can achieve efficient adsorption of target substances in a relatively short time, greatly improving the adsorption efficiency and reducing the processing time and cost. By controlling the pore size, surface properties and functional groups of the material, selective adsorption of specific ions or molecules can be achieved, effectively separating and removing target substances in complex mixed systems and improving the precision and purity of adsorption. During the adsorption process, the porous polyethylene / carbon black composite electrode material has good electrochemical stability and reversibility, and can maintain high adsorption performance after multiple adsorption-desorption cycles, reducing the cost of pollutant treatment and improving resource utilization. Compared with traditional adsorption materials, the porous polyethylene / carbon black composite electrode material has good chemical stability and biocompatibility, is less likely to cause secondary pollution, is more environmentally friendly, and meets the requirements of sustainable development. SUMMARY

[0004] Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the purposes of the present application is to at least solve one or more of the above-mentioned problems in the prior art, in other words, one of the purposes of the present application is to provide a porous polyethylene / carbon black composite electrode material, a preparation method thereof and application thereof, which meet one or more of the aforementioned needs.

[0005] In order to achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0006] A porous polyethylene / carbon black composite electrode material, comprising polyethylene / carbon black composite fibers prepared by melt spinning, and the surface of the polyethylene / carbon black composite fibers is crosslinked with cyclodextrin through a crosslinking agent containing a halogen functional group.

[0007] The present application also provides a preparation method of the porous polyethylene / carbon black composite electrode material as described in the above scheme, comprising the following steps:

[0008] S1, adding polyethylene and carbon black into a melt spinning machine to perform melt spinning to obtain polyethylene / carbon black composite fibers;

[0009] S2, performing plasma etching on the polyethylene / carbon black composite fibers;

[0010] S3, adding cyclodextrin and a solvent thereof, the polyethylene / carbon black composite fibers after plasma etching, a catalyst and a crosslinking agent containing a halogen functional group into a reaction container to stir, and then performing crosslinking polymerization reaction, and then performing washing, freeze-drying to obtain the porous polyethylene / carbon black composite electrode material.

[0011] As a preferred scheme, in the step S1, melt spinning is performed under the condition of 140-240 DEG C, and then cooling and solidification are performed through a water bath, and stretching is performed by 1-3 times under the condition of 80-120 DEG C;

[0012] The weight ratio of polyethylene to carbon black is (5-10):1.

[0013] As a preferred scheme, in the step S2, the plasma etching time is 1-3 h.

[0014] As a preferred scheme, in the step S3, the weight ratio of cyclodextrin to the polyethylene / carbon black composite fibers after plasma etching is (1-2):1.

[0015] As a preferred scheme, in the step S3, the weight ratio of cyclodextrin, a catalyst and a crosslinking agent containing a halogen functional group is 1:(0.3-3):(0.3-3).

[0016] As a preferred scheme, in the step S3, the stirring speed of the crosslinking polymerization reaction is 500-1500 rpm, the reaction temperature is 60-80 DEG C, and the reaction time is 6-12 h.

[0017] As a preferred scheme, in the step S3, the cyclodextrin comprises one of alpha-cyclodextrin, beta-cyclodextrin and gamma-cyclodextrin.

[0018] The solvent comprises one or both of N,N-dimethylformamide and tetrahydrofuran;

[0019] The catalyst comprises one of cesium carbonate, potassium carbonate or sodium carbonate;

[0020] The cross-linking agent comprises one of tetrafluoroterephthalonitrile, tetrafluorophthalonitrile, tetrachloroterephthalonitrile, tetrachlorophthalonitrile or hexachlorocyclotriphosphazene.

[0021] As a preferred solution, the temperature for freeze-drying in the step S3 is -90 to -30℃, and the drying time is 24 to 72h.

[0022] The application also provides the application of the porous polyethylene / carbon black composite electrode material prepared according to the above solutions or the preparation method according to any one of the above solutions, which is used for adsorbing and removing heavy metal ions in industrial wastewater.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] (1) The porous polyethylene / carbon black composite electrode material is prepared by the following steps: preparing the porous polyethylene / carbon black composite fiber through the melt spinning method, and then etching and cross-linking and polymerizing with the cyclodextrin and the small molecule monomer of the halogen-containing functional group through the low-temperature plasma technology. Compared with the existing electrode material, the porous polyethylene / carbon black composite electrode material prepared by the application not only has a multi-level pore structure and a higher specific surface area, but also has a variety of active functional group combination sites, and can be used for the efficient adsorption and removal of heavy metal ions in industrial wastewater.

[0025] (2) The porous polyethylene / carbon black composite electrode material can be recycled, and can be used for the adsorption and removal of heavy metal ions in wastewater. After 20 cycles of adsorption, the adsorption effect is still high. The regeneration process of the adsorption material is simple, and the recovery cost is low.

[0026] (3) The preparation method of the porous polyethylene / carbon black composite electrode material is simple, the reaction conditions are relatively mild and not harsh, the process is safe, and a specific reaction device is not needed. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a reaction process schematic diagram of the porous polyethylene / carbon black composite electrode material of the embodiment 12 of the application. DETAILED DESCRIPTION

[0028] The technical solutions of the application are further explained and described below through specific embodiments.

[0029] The molecular structure and composition of the porous polyethylene / carbon black composite electrode material finally synthesized by the embodiments of the application are determined by a nuclear magnetic resonance instrument (NMR). 13 C NMR, 1H NMR) and Fourier transform infrared spectrometer (FTIR) for testing analysis; the specific surface area, porosity, pore size and distribution range of the porous polyethylene / carbon black composite electrode material are tested and analyzed by BET.

[0030] The adsorption effect of the porous polyethylene / carbon black composite electrode material on heavy metal ions in wastewater is tested and analyzed by atomic energy spectrometer (ICP), and the testing method is as follows: prepare a Sb 3+ solution with a mass concentration of 100-1000 mg / L, put the prepared electrode into the above solution, connect the direct current power supply and the electrode clamp, so that the electrode can be stably soaked in the solution and the solution can fully contact the surface of the electrode. Turn on the direct current power supply, take out a small amount of solution sample at certain time intervals (such as 5 min, 10 min, etc.), test and analyze the concentration of target ions in the solution by atomic energy spectrometer (ICP), and record the change of concentration with time.

[0031] The specific cyclic regeneration process of the porous polyethylene / carbon black composite electrode material is as follows: short-circuit the positive and negative electrodes or change the polarity of the power supply, so that the adsorbed ions on the electrode are desorbed. Similarly, during the desorption process, take out the solution sample at certain time intervals to determine the ion concentration and observe the change of ion concentration until the desorption is completed and the ion concentration returns to close to the initial concentration.

[0032] Example 1:

[0033] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0034] (1) Add high molecular weight polyethylene (10 g) and carbon black (1 g) into a melt spinning machine, melt spinning at 140℃, and then cool and solidify in a water bath, stretch 2 times at 80℃, to obtain polyethylene / carbon black composite fiber. The weight ratio of high molecular weight polyethylene to carbon black is 10:1.

[0035] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 1 h.

[0036] (3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then β-cyclodextrin (β-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (5 g) and tetrachloro-p-phenylenedinitrile (5 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of β-cyclodextrin to potassium carbonate is 1:1, and the weight ratio of the addition amount of β-cyclodextrin to tetrachloro-p-phenylenedinitrile is 1:1. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 36 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0037] The specific surface area S BET of the above-synthesized porous polyethylene / carbon black composite electrode material is 83.47 m 2 / g, and the porosity is 56.6%. The sample as an electrode material has an electric adsorption rate of up to 91.2% for heavy metal ions (Sb 3+ ). After 20 cycles of adsorption, the sample has an electric adsorption rate of up to 78.5% for heavy metal ions (Sb 3+ ).

[0038] Example 2:

[0039] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0040] (1) High molecular weight polyethylene (10 g) and carbon black (2 g) are added to a melt spinning machine, and melt spinning is performed at 140°C, and then water bath cooling and solidification are performed, and then the polyethylene / carbon black composite fiber is obtained by stretching 3 times at 80°C. The weight ratio of high molecular weight polyethylene to carbon black is 5:1.

[0041] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 1 h;

[0042] (3) After the reaction in step (2) is completed, 180 ml of N,N-dimethylformamide (DMF) is placed in a round-bottom flask. Then, β-cyclodextrin (β-CD, 5 g) and plasma-etched polyethylene / carbon black composite fiber (5 g) are added to the round-bottom flask and stirred thoroughly for 1 h at a stirring speed of 600 rpm. Then, potassium carbonate (5 g) and tetrafluoroterephthalonitrile (10 g) are added to the round-bottom flask and stirred to carry out cross-linking polymerization. The reaction temperature is 80 °C, the reaction time is 48 h, and the stirring speed is 600 rpm. The weight ratio of β-cyclodextrin to potassium carbonate is 1:1, and the weight ratio of β-cyclodextrin to tetrafluoroterephthalonitrile is 1:2. The solid product is then washed three times in 200 ml of deionized water. The resulting product is then freeze-dried at -80 °C for 48 h to obtain a porous polyethylene / carbon black composite electrode material.

[0043] The above-synthesized porous polyethylene / carbon black composite electrode material has a specific surface area S BET =105.13m 2 / g, with a porosity as high as 61.6%. As an electrode material, the sample exhibits good adhesion to heavy metal ions (Sb... 3+ The electroadsorption rate of the sample reached as high as 98.9%. After 20 cycles of adsorption, the sample showed a high electroadsorption rate for heavy metal ions (Sb). 3+ The electroadsorption rate is as high as 90.3%.

[0044] Example 3:

[0045] The preparation method of the porous polyethylene / carbon black composite electrode material in this embodiment includes the following steps:

[0046] (1) High molecular weight polyethylene (10g) and carbon black (2g) were added to a melt spinning machine and melt spun at 140℃. After cooling and solidification in a water bath, the fibers were stretched twice at 80℃ to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 5:1.

[0047] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 3 hours.

[0048] (3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then α-cyclodextrin (α-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (10 g) and tetrachloro-p-phenylenedinitrile (10 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of α-cyclodextrin to potassium carbonate is 1:2, and the weight ratio of the amount of α-cyclodextrin added to tetrachloro-p-phenylenedinitrile is 1:2. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 72 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0049] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 101.51 m BET 2 / g, and the porosity is as high as 58.9%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 95.9%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 87.9%.

[0050] Example 4:

[0051] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0052] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, melt spinning is performed at 140°C, and then water bath cooling and solidification are performed, and the polyethylene / carbon black composite fiber is obtained by stretching 2 times at 80°C. The weight ratio of high molecular weight polyethylene to carbon black is 10:1.

[0053] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 2 h;

[0054] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then β-cyclodextrin (β-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (15 g) and tetrachloro-p-phenylenedinitrile (5 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of β-cyclodextrin to potassium carbonate is 1:3, and the weight ratio of the addition amount of β-cyclodextrin to tetrachloro-p-phenylenedinitrile is 1:1. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 72 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0055] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 112.58 m BET 2 / g, and the porosity is as high as 73.1%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 99.9%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 97.1%.

[0056] Example 5:

[0057] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0058] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, and melt spinning is performed at 140°C, and then water bath cooling and solidification are performed, and then the polyethylene / carbon black composite fiber is obtained by stretching 2 times at 120°C. The weight ratio of high molecular weight polyethylene to carbon black is 10:1.

[0059] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 1 h;

[0060] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then β-cyclodextrin (β-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (15 g) and tetrachloro-p-phenylenedinitrile (5 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of β-cyclodextrin to potassium carbonate is 1:3, and the weight ratio of the addition amount of β-cyclodextrin to tetrachloro-p-phenylenedinitrile is 1:1. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 48 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0061] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 91.12 m BET 2 / g, and the porosity is as high as 88.9%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 95.9%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 90.1%.

[0062] Example 6:

[0063] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0064] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, and melt spinning is performed at 140°C, and then water bath cooling and solidification are performed, and then the polyethylene / carbon black composite fiber is obtained by stretching 2 times at 120°C. The weight ratio of high molecular weight polyethylene to carbon black is 10:1.

[0065] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 1 h;

[0066] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then β-cyclodextrin (β-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (10 g) and tetrachloro-p-phenylenedinitrile (10 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of β-cyclodextrin to potassium carbonate is 1:2, and the weight ratio of the addition amount of β-cyclodextrin to tetrachloro-p-phenylenedinitrile is 1:2. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 48 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0067] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 96.72 m BET 2 / g, and the porosity is as high as 70.1%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 96.9%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 83.3%.

[0068] Example 7:

[0069] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0070] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, melt spinning is performed at 140°C, and then water bath cooling and solidification are performed, and the polyethylene / carbon black composite fiber is obtained by stretching 3 times at 80°C. The weight ratio of high molecular weight polyethylene to carbon black is 10:1.

[0071] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 2 h;

[0072] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then α-cyclodextrin (α-CD, 10 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (5 g) and tetrachloro-p-phenylenedinitrile (5 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of α-cyclodextrin to potassium carbonate is 2:1, and the weight ratio of the amount of α-cyclodextrin added to tetrachloro-p-phenylenedinitrile is 1:1. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 72 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0073] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 85.69 m BET 2 / g, and the porosity is as high as 56.9%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 86.8%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 81.5%.

[0074] Example 8:

[0075] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0076] (1) High molecular weight polyethylene (10 g) and carbon black (2 g) are added to a melt spinning machine, and melt spinning is performed at 240°C, and then water bath cooling and solidification are performed, and then the polyethylene / carbon black composite fiber is obtained by stretching 2 times at 80°C. The weight ratio of high molecular weight polyethylene to carbon black is 5:1.

[0077] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 1 h;

[0078] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then β-cyclodextrin (β-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (15 g) and tetrachloro-p-phenylenedinitrile (5 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of β-cyclodextrin to potassium carbonate is 1:3, and the weight ratio of the addition amount of β-cyclodextrin to tetrachloro-p-phenylenedinitrile is 1:1. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 48 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0079] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 96.53 m BET 2 / g, and the porosity is as high as 64.7%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 95.9%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 90.1%.

[0080] Example 9:

[0081] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0082] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, and melt spinning is performed at 200°C, and then water bath cooling and solidification are performed, and then the polyethylene / carbon black composite fiber is obtained by stretching 1 times at 80°C. The weight ratio of high molecular weight polyethylene to carbon black is 10:1.

[0083] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 3 h;

[0084] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, then γ-cyclodextrin (γ-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirring is performed at a speed of 600 rpm for 1 h, then cesium carbonate (10 g) and tetrachloro-p-xylylene (2.5 g) are added to the round-bottom flask, and crosslinking polymerization is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of γ-cyclodextrin to potassium carbonate is 1:2, and the weight ratio of the amount of γ-cyclodextrin to tetrachloro-p-xylylene added is 2:1. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 72 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0085] The specific surface area S of the porous polyethylene / carbon black composite electrode material synthesized above is 72.68 m BET 2 / g, and the porosity is as high as 44.1%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 75.6%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 60.6%.

[0086] Example 10:

[0087] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0088] (1) High-density polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, melt spinning is performed at 160°C, then water bath cooling and solidification are performed, and the polyethylene / carbon black composite fiber is obtained by stretching 2 times at 80°C. The weight ratio of high-molecular-weight polyethylene to carbon black is 10:1.

[0089] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 2 h;

[0090] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then γ-cyclodextrin (γ-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (10 g) and tetrachloro-p-phenylenedinitrile (10 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of γ-cyclodextrin to potassium carbonate is 1:2, and the weight ratio of the added amount of γ-cyclodextrin to tetrachloro-p-phenylenedinitrile is 1:2. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -70°C, the drying time is 72 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0091] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 91.21 m BET 2 / g, and the porosity is as high as 63.1%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 94.1%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 89.9%.

[0092] Example 11:

[0093] The preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment comprises the following steps:

[0094] (1) High-density polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, and melt spinning is performed at 200°C, and then water bath cooling and solidification are performed, and then the polyethylene / carbon black composite fiber is obtained by stretching 2 times at 80°C. The weight ratio of high-molecular-weight polyethylene to carbon black is 10:1.

[0095] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 3 h;

[0096] ​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then β-cyclodextrin (β-CD, 5 g) and the polyethylene / carbon black composite fiber after plasma etching (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then potassium carbonate (15 g) and tetrachloro-p-phenylenedinitrile (15 g) are added to the round-bottom flask, and a crosslinking polymerization reaction is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of β-cyclodextrin to potassium carbonate is 1:3, and the weight ratio of the addition amount of β-cyclodextrin to tetrachloro-p-phenylenedinitrile is 1:3. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 72 h, and a porous polyethylene / carbon black composite electrode material is obtained.

[0097] The specific surface area S of the above-synthesized porous polyethylene / carbon black composite electrode material is 91.67 m BET 2 / g, and the porosity is as high as 61.8%. The sample as an electrode material has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 93.3%. After 20 cycles of adsorption, the sample has an electric adsorption rate of heavy metal ions (Sb 3+ ) as high as 88.6%.

[0098] Example 12:

[0099] As shown in the following table, the preparation method of the porous polyethylene / carbon black composite electrode material of the present embodiment includes the following steps: Figure 1

[0100] (1) High-density polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, and melt spinning is performed at 140°C, and then water bath cooling and solidification are performed, and then stretching is performed at 80°C by 2 times, and a polyethylene / carbon black composite fiber is obtained. The weight ratio of high-molecular-weight polyethylene to carbon black is 10:1.

[0101] (2) After the reaction in step (1) is completed, the composite fiber obtained in step (1) is subjected to plasma etching for 1 h;

[0102] ​​(3) After the reaction in step (2) is completed, 180 ml of N, N-dimethylformamide (DMF) is placed in a round-bottom flask, and then β-cyclodextrin (β-CD, 5 g) and the plasma-etched polyethylene / carbon black composite fiber (5 g) are added to the round-bottom flask, and stirred for 1 h at a stirring speed of 600 rpm, and then cesium carbonate (5 g) and hexachlorocyclotriphosphazene (PNC, 5 g) are added to the round-bottom flask, and crosslinking polymerization is performed by stirring, the reaction temperature is 70°C, the reaction time is 48 h, the stirring speed is 600 rpm, the weight ratio of β-cyclodextrin to potassium carbonate is 1:1, and the weight ratio of the added amounts of β-cyclodextrin and hexachlorocyclotriphosphazene is 1:1. Then the solid product is repeatedly washed in 200 ml of deionized water for 3 times, and then the obtained product is freeze-dried at -80°C, the drying time is 72 h, and the porous polyethylene / carbon black composite electrode material is obtained.

[0103] The specific surface area S of the synthesized porous polyethylene / carbon black composite electrode material is 106.91 m BET 2 / g, and the porosity is as high as 74.6%. The sample as an electrode material has an electric adsorption rate of 99.9% for heavy metal ions (Sb 3+ ). After 20 cycles of adsorption, the sample has an electric adsorption rate of 98.1% for heavy metal ions (Sb 3+ ).

[0104] Comparative Example 1:

[0105] The preparation method of the polyethylene / carbon black composite fiber in the present comparative example comprises the following steps:

[0106] High-density polyethylene (10 g) and carbon black (1 g) are added to a melt spinning machine, melt spinning is performed at 140°C, and then water bath cooling and solidification are performed, and then the polyethylene / carbon black composite fiber is obtained by stretching 2 times at 80°C. The weight ratio of the high-molecular-weight polyethylene to the carbon black is 10:1.

[0107] The electric adsorption rate of the synthesized polyethylene / carbon black composite fiber material for heavy metal ions (Sb 3+ ) is only 5.2%, and almost no adsorption of heavy metal ions is achieved, because the polyethylene / carbon black composite surface has no active binding sites that can effectively bind heavy metal ions, and thus cannot effectively adsorb heavy metal ions.

[0108] In view of the numerous embodiments of the present application, the raw materials and amounts involved can be selected according to actual needs within the limited range, and the experimental data of each embodiment are too numerous to be listed and described one by one here.

[0109] ​The above merely describes the preferred embodiments and principles of the present application in detail, and for those skilled in the art, according to the ideas provided by the present application, there will be changes in the specific implementation manner, and these changes should also be considered as the protection scope of the present application.

Claims

1. A porous polyethylene / carbon black composite electrode material, characterized in that, Including polyethylene / carbon black composite fibers obtained by melt spinning, wherein the surface of the polyethylene / carbon black composite fibers is cross-linked with cyclodextrin by a cross-linking agent containing halogen functional groups; The crosslinking agent includes one of tetrafluoroterephthalonitrile, tetrafluorophthalonitrile, tetrachloroterephthalonitrile, tetrachlorophthalonitrile, and hexachlorocyclotriphosphazene.

2. The method for preparing the porous polyethylene / carbon black composite electrode material as described in claim 1, characterized in that, Includes the following steps: S1. Polyethylene and carbon black are added to a melt spinning machine for melt spinning to obtain polyethylene / carbon black composite fiber; S2. Plasma etching is performed on polyethylene / carbon black composite fibers; S3. Cyclodextrin and its solvent, plasma-etched polyethylene / carbon black composite fibers are added to a reaction vessel and stirred. Then, a catalyst and a crosslinking agent containing halogen functional groups are added to carry out a crosslinking polymerization reaction. After the reaction, the material is washed and freeze-dried to obtain a porous polyethylene / carbon black composite electrode material. The catalyst includes one of cesium carbonate, potassium carbonate, or sodium carbonate.

3. The preparation method according to claim 2, characterized in that, In step S1, melt spinning is performed at 140–240°C, followed by cooling and solidification in a water bath, and then stretching by 1–3 times at 80–120°C. The weight ratio of polyethylene to carbon black is (5-10):

1.

4. The preparation method according to claim 2, characterized in that, In step S2, the plasma etching time is 1 to 3 hours.

5. The preparation method according to claim 2, characterized in that, In step S3, the weight ratio of cyclodextrin to plasma-etched polyethylene / carbon black composite fiber is (1-2):

1.

6. The preparation method according to claim 2, characterized in that, In step S3, the weight ratio of cyclodextrin, catalyst, and crosslinking agent containing halogen functional groups is 1:(0.3-3):(0.3-3).

7. The preparation method according to claim 2, characterized in that, In step S3, the stirring speed of the crosslinking polymerization reaction is 500-1500 rpm, the reaction temperature is 60-80℃, and the reaction time is 6-12 h.

8. The preparation method according to claim 2, characterized in that, In step S3, the cyclodextrin includes one of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. The solvent includes one or two of N, N-dimethylformamide, and tetrahydrofuran.

9. The preparation method according to claim 2, characterized in that, In step S3, the freeze-drying temperature is -90 to -30°C, and the drying time is 24 to 72 hours.

10. The application of the porous polyethylene / carbon black composite electrode material as described in claim 1 or the porous polyethylene / carbon black composite electrode material prepared by the preparation method according to any one of claims 2-9, characterized in that, Used for adsorption and removal of heavy metal ions from industrial wastewater.

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