Multi-channel polyethylene / carbon black composite electrode material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of functional electrode materials, and particularly relates to a porous polyethylene / carbon black composite electrode material and a preparation method and application thereof. The multi-channel polyethylene / carbon black composite electrode material comprises polyethylene / carbon black composite fibers prepared through melt spinning, and cyclodextrin is crosslinked on the surfaces of the polyethylene / carbon black composite fibers through a crosslinking agent containing halogen functional groups. The porous polyethylene / carbon black composite electrode material is prepared by preparing a porous polyethylene / carbon black composite fiber through a melt spinning method and then carrying out cross-linking polymerization on the porous polyethylene / carbon black composite fiber, cyclodextrin and a cross-linking agent micromolecular monomer containing a halogen functional group through low-temperature plasma technology etching. Compared with an existing electrode material, the prepared multi-channel polyethylene / carbon black composite electrode material has a hierarchical pore structure and a relatively high specific surface area, has various active functional group binding sites, and can be used for efficiently adsorbing and removing heavy metal ions in industrial wastewater.

Description

Technical Field

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

[0002] Carbon black itself has a high specific surface area and good conductivity. Carbon black composite electrode materials can provide abundant adsorption sites, ensuring that the electrodes can effectively transfer electrons during the electrosorption process. This helps to maintain the stability of the electric field, so that the adsorption process can be carried out continuously and efficiently, and more pollutants can be adsorbed. Even when treating high-concentration wastewater, the electric field strength between the electrodes can be guaranteed to avoid the decrease in adsorption efficiency due to excessive resistance. In the complex chemical environment of wastewater, carbon black composite electrode materials can remain stable. It can resist the corrosion of chemicals such as acids, alkalis, and salts in wastewater, and extend the service life of the electrode. Polyethylene, as a matrix material, gives the composite electrode material certain mechanical properties. By adjusting the type and molecular weight of polyethylene, as well as 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 a certain extent to meet the needs of different application scenarios. However, in actual application, as the adsorption process proceeds, the adsorption sites are gradually occupied, and the adsorption capacity will quickly reach saturation. In addition, it is difficult to achieve efficient and precise adsorption of specific substances in a complex mixed system.

[0003] The porous polyethylene / carbon black composite electrode material can achieve efficient adsorption of the target substance in a short time, greatly improving the adsorption efficiency and reducing the processing time and cost. By regulating the pore size, surface properties and functional groups of the material, the selective adsorption of specific ions or molecules can be achieved, thereby effectively separating and removing the target substance in a complex mixed system and improving the accuracy and purity of the adsorption. During the adsorption process, the porous polyethylene / carbon black composite electrode material has good electrochemical stability and reversibility. After multiple adsorption-desorption cycles, it can still maintain a high adsorption performance, reduce the cost of pollutant treatment, and improve resource utilization. Compared with traditional adsorption materials, the porous polyethylene / carbon black composite electrode material has good chemical stability and biocompatibility, is not easy to produce secondary pollution, is more environmentally friendly, and meets the requirements of sustainable development. Summary of the invention

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

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] A porous polyethylene / carbon black composite electrode material comprises 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.

[0007] The present invention also provides a method for preparing 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 for melt spinning to obtain polyethylene / carbon black composite fibers;

[0009] S2, plasma etching the polyethylene / carbon black composite fiber;

[0010] S3. Add cyclodextrin and its solvent, and polyethylene / carbon black composite fibers after plasma etching into a reaction container and stir, then add a catalyst and a cross-linking agent containing a halogen functional group to carry out a cross-linking polymerization reaction, wash and freeze-dry after the reaction to obtain a porous polyethylene / carbon black composite electrode material.

[0011] As a preferred embodiment, in step S1, melt spinning is performed at 140-240° C., then cooled and solidified in a water bath, and stretched 1-3 times at 80-120° C.;

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

[0013] As a preferred solution, in step S2, the plasma etching time is 1 to 3 hours.

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

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

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

[0017] As a preferred embodiment, in step S3, the cyclodextrin includes one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin;

[0018] The solvent includes one or two of N, N-dimethylformamide and tetrahydrofuran;

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

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

[0021] As a preferred embodiment, in step S3, the freeze-drying temperature is -90 to -30°C, and the drying time is 24 to 72 hours.

[0022] The present invention also provides the use of the porous polyethylene / carbon black composite electrode material as described in the above scheme or the porous polyethylene / carbon black composite electrode material prepared by the preparation method described in any of the above schemes for adsorbing and removing heavy metal ions in industrial wastewater.

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

[0024] (1) The present invention prepares a porous polyethylene / carbon black composite fiber by melt spinning, and then uses low-temperature plasma technology to etch and cross-link with cyclodextrin and a small molecule monomer containing a halogen functional group to prepare a porous polyethylene / carbon black composite electrode material. Compared with existing electrode materials, the porous polyethylene / carbon black composite electrode material prepared by the present invention not only has a multi-level pore structure and a high specific surface area, but also has a variety of active functional group binding sites, which 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 of the present invention can be recycled. It is used to adsorb and remove heavy metal ions in wastewater. After 20 cycles of adsorption, it can still maintain a high adsorption effect. The regeneration process of the adsorption material is simple and the recycling cost is low.

[0026] (3) The preparation method of the porous polyethylene / carbon black composite electrode material of the present invention is simple, the reaction conditions are mild and not harsh, the process is safe, and no specific reaction device is required. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] The technical solution of the present invention is further explained below through specific embodiments.

[0029] The molecular structure and composition of the porous polyethylene / carbon black composite electrode material finally synthesized in the embodiment of the present invention were analyzed by nuclear magnetic resonance (NMR) 13 C NMR, 1H NMR) and Fourier transform infrared spectrometer (FTIR) were used for testing and analysis; the specific surface area, porosity, pore size and distribution range of the porous polyethylene / carbon black composite electrode material were analyzed by BET test.

[0030] The adsorption effect of the porous polyethylene / carbon black composite electrode material on heavy metal ions in wastewater was analyzed by atomic energy spectrometry (ICP). The specific test method is as follows: Sb with a mass concentration of 100-1000 mg / L was prepared. 3+ Solution, place the prepared electrode in the above solution, connect the DC power supply and the electrode fixture, so that the electrode can be stably immersed in the solution, and ensure that the solution can fully contact the electrode surface. Turn on the DC power supply, take out a small amount of solution sample at a certain time interval (such as 5min, 10min, etc.), use an atomic energy spectrometer (ICP) to test and analyze the concentration of the target ion in the solution, and record the change of concentration over time.

[0031] The specific recycling process of the porous polyethylene / carbon black composite electrode material is: short-circuit the positive and negative electrodes or change the polarity of the power supply to desorb the ions adsorbed on the electrodes. Similarly, during the desorption process, take out solution samples at regular intervals to measure the ion concentration and observe the change in ion concentration until the desorption is completed and the ion concentration is restored to a value close to the initial concentration.

[0032] Embodiment 1:

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

[0034] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spun at 140° C., then cooled and solidified in a water bath, and stretched 2 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0036] (3) After the reaction of 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 plasma-etched polyethylene / carbon black composite fiber (5 g) are added to the round-bottom flask, and stirred for 1 hour at a stirring speed of 600 rpm. Then potassium carbonate (5 g) and tetrafluoroterephthalonitrile (5 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 hours, a stirring speed of 600 rpm, a weight ratio of β-cyclodextrin to potassium carbonate of 1:1, and a weight ratio of β-cyclodextrin to tetrafluoroterephthalonitrile of 1:1. Then the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 36 hours to obtain a porous polyethylene / carbon black composite electrode material.

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

[0038] Embodiment 2:

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

[0040] (1) High molecular weight polyethylene (10 g) and carbon black (2 g) were added to a melt spinning machine, melt-spun at 140° C., then cooled and solidified in a water bath, and stretched 3 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 5:1.

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

[0042] (3) After the reaction of 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 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. Then potassium carbonate (5 g) and tetrafluoroterephthalonitrile (10 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring. The reaction temperature is 80°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 β-cyclodextrin to tetrafluoroterephthalonitrile is 1:2. Then the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is 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, the porosity is as high as 61.6%. The sample is used as an electrode material, and its resistance to heavy metal ions (Sb 3+ ) has an electrosorption rate of up to 98.9%. After 20 cycles of adsorption, the sample has a high adsorption rate for heavy metal ions (Sb 3+ ) has an electrosorption rate of up to 90.3%.

[0044] Embodiment 3:

[0045] The method for preparing the porous polyethylene / carbon black composite electrode material of this embodiment comprises the following steps:

[0046] (1) High molecular weight polyethylene (10 g) and carbon black (2 g) were added to a melt spinning machine, melt-spinning was performed at 140° C., then cooled and solidified in a water bath, and stretched 2 times at 80° C. 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 by the reaction in step (1) is subjected to plasma etching by plasma etching for 3 hours;

[0048] (3) After the reaction of 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 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. Then potassium carbonate (10 g) and tetrafluoroterephthalonitrile (10 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 h, a stirring speed of 600 rpm, and a weight ratio of α-cyclodextrin to potassium carbonate is 1:2, and a weight ratio of α-cyclodextrin to tetrafluoroterephthalonitrile is 1:2. Then the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 72 h to obtain a porous polyethylene / carbon black composite electrode material.

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

[0050] Embodiment 4:

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

[0052] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spun at 140° C., then cooled and solidified in a water bath, and stretched 2 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0054] (3) After the reaction of 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 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. Potassium carbonate (15 g) and tetrafluoroterephthalonitrile (5 g) are then added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 h, a stirring speed of 600 rpm, a weight ratio of β-cyclodextrin to potassium carbonate of 1:3, and a weight ratio of β-cyclodextrin to tetrafluoroterephthalonitrile of 1:1. The solid product is then placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 72 h to obtain a porous polyethylene / carbon black composite electrode material.

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

[0056] Embodiment 5:

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

[0058] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spinning was performed at 140° C., then cooled and solidified in a water bath, and stretched 2 times at 120° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0060] (3) After the reaction of 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 plasma-etched polyethylene / carbon black composite fiber (5 g) are added to the round-bottom flask, and stirred for 1 hour at a stirring speed of 600 rpm. Then potassium carbonate (15 g) and tetrafluoroterephthalonitrile (5 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 hours, a stirring speed of 600 rpm, a weight ratio of β-cyclodextrin to potassium carbonate of 1:3, and a weight ratio of β-cyclodextrin to tetrafluoroterephthalonitrile of 1:1. Then the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 48 hours to obtain a porous polyethylene / carbon black composite electrode material.

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

[0062] Embodiment 6:

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

[0064] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spinning was performed at 140° C., then cooled and solidified in a water bath, and stretched 2 times at 120° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0066] (3) After the reaction of 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 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. Potassium carbonate (10 g) and tetrafluoroterephthalonitrile (10 g) are then added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70° C., a reaction time of 48 h, a stirring speed of 600 rpm, a β-cyclodextrin to potassium carbonate feed weight ratio of 1:2, and a β-cyclodextrin to tetrafluoroterephthalonitrile addition weight ratio of 1:2. The solid product is then placed in 200 ml of deionized water and repeatedly washed 3 times, and then the obtained product is freeze-dried at -80° C. for 48 h to obtain a porous polyethylene / carbon black composite electrode material.

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

[0068] Embodiment 7:

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

[0070] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spun at 140° C., then cooled and solidified in a water bath, and stretched 3 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0072] (3) After the reaction of 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 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. Then potassium carbonate (5 g) and tetrafluoroterephthalonitrile (5 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 h, a stirring speed of 600 rpm, and a weight ratio of α-cyclodextrin to potassium carbonate of 2:1, and a weight ratio of α-cyclodextrin to tetrafluoroterephthalonitrile of 1:1. Then the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 72 h to obtain a porous polyethylene / carbon black composite electrode material.

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

[0074] Embodiment 8:

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

[0076] (1) High molecular weight polyethylene (10 g) and carbon black (2 g) were added to a melt spinning machine, melt-spun at 240° C., then cooled and solidified in a water bath, and stretched 2 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 5:1.

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

[0078] (3) After the reaction of 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 plasma-etched polyethylene / carbon black composite fiber (5 g) are added to the round-bottom flask, and stirred for 1 hour at a stirring speed of 600 rpm. Then potassium carbonate (15 g) and tetrafluoroterephthalonitrile (5 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 hours, a stirring speed of 600 rpm, a weight ratio of β-cyclodextrin to potassium carbonate of 1:3, and a weight ratio of β-cyclodextrin to tetrafluoroterephthalonitrile of 1:1. Then the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 48 hours to obtain a porous polyethylene / carbon black composite electrode material.

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

[0080] Embodiment 9:

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

[0082] (1) High molecular weight polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spinning was performed at 200° C., then cooled and solidified in a water bath, and stretched by 1 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0084] (3) After the reaction of 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 plasma-etched polyethylene / carbon black composite fiber (5 g) are added to the round-bottom flask, and stirred thoroughly for 1 hour at a stirring speed of 600 rpm. Then, cesium carbonate (10 g) and tetrafluoroterephthalonitrile (2.5 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70° C., a reaction time of 48 hours, a stirring speed of 600 rpm, a weight ratio of γ-cyclodextrin to potassium carbonate of 1:2, and a weight ratio of γ-cyclodextrin to tetrafluoroterephthalonitrile of 2:1. Then, the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80° C. for 72 hours to obtain a porous polyethylene / carbon black composite electrode material.

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

[0086] Embodiment 10:

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

[0088] (1) High-density polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spun at 160° C., then cooled and solidified in a water bath, and stretched 2 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0090] (3) After the reaction of 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 plasma-etched polyethylene / carbon black composite fiber (5 g) are added to the round-bottom flask, and stirred thoroughly for 1 hour at a stirring speed of 600 rpm. Then potassium carbonate (10 g) and tetrafluoroterephthalonitrile (10 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 hours, a stirring speed of 600 rpm, a weight ratio of γ-cyclodextrin to potassium carbonate of 1:2, and a weight ratio of γ-cyclodextrin to tetrafluoroterephthalonitrile of 1:2. Then the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -70°C for 72 hours to obtain a porous polyethylene / carbon black composite electrode material.

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

[0092] Embodiment 11:

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

[0094] (1) High-density polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spun at 200° C., then cooled and solidified in a water bath, and stretched 2 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0096] (3) After the reaction of 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 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. Potassium carbonate (15 g) and tetrafluorophthalonitrile (15 g) are then added to the round-bottom flask, and a cross-linking polymerization reaction is carried out by stirring at a reaction temperature of 70°C, a reaction time of 48 h, a stirring speed of 600 rpm, a weight ratio of β-cyclodextrin to potassium carbonate of 1:3, and a weight ratio of β-cyclodextrin to tetrafluorophthalonitrile of 1:3. The solid product is then placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 72 h to obtain a porous polyethylene / carbon black composite electrode material.

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

[0098] Embodiment 12:

[0099] like Figure 1 As shown, the method for preparing the porous polyethylene / carbon black composite electrode material of this embodiment comprises the following steps:

[0100] (1) High-density polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spun at 140° C., then cooled and solidified in a water bath, and stretched 2 times at 80° C. to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

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

[0102] (3) After the reaction of 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 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. Then, cesium carbonate (5 g) and hexachlorocyclotriphosphazene (PNC, 5 g) are added to the round-bottom flask, and a cross-linking polymerization reaction is carried out 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 β-cyclodextrin to hexachlorocyclotriphosphazene is 1:1. Then, the solid product is placed in 200 ml of deionized water and washed repeatedly for 3 times, and then the obtained product is freeze-dried at -80°C for 72 h to obtain a porous polyethylene / carbon black composite electrode material.

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

[0104] Comparative Example 1:

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

[0106] High-density polyethylene (10 g) and carbon black (1 g) were added to a melt spinning machine, melt-spun at 140°C, then cooled and solidified in a water bath, and stretched 2 times at 80°C to obtain polyethylene / carbon black composite fibers. The weight ratio of high molecular weight polyethylene to carbon black was 10:1.

[0107] The synthesized polyethylene / carbon black composite fiber material has a strong affinity for heavy metal ions (Sb 3+ ) has an electrical adsorption rate of only 5.2%, and almost no heavy metal ions are adsorbed. The reason is that there are no active binding sites on the polyethylene / carbon black composite surface that can effectively bind heavy metal ions, and the effective adsorption of heavy metal ions cannot be achieved.

[0108] In view of the numerous embodiments of the present invention, the raw materials and amounts involved can be selected within a limited range according to actual needs. The experimental data of each embodiment is huge and numerous, and it is not suitable to list them one by one here.

[0109] The above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, according to the ideas provided by the present invention, there will be changes in the specific implementation methods, and these changes should also be regarded as the protection scope of the present invention.

Claims

1. A porous polyethylene / carbon black composite electrode material, characterized in that: The invention comprises polyethylene / carbon black composite fibers prepared 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.

2. The method for preparing a porous polyethylene / carbon black composite electrode material according to claim 1, characterized in that: The following steps are involved: S1, adding polyethylene and carbon black into a melt spinning machine for melt spinning to obtain polyethylene / carbon black composite fibers; S2, plasma etching the polyethylene / carbon black composite fiber; S3. Add cyclodextrin and its solvent, and polyethylene / carbon black composite fibers after plasma etching into a reaction container and stir, then add a catalyst and a cross-linking agent containing a halogen functional group to carry out a cross-linking polymerization reaction, wash and freeze-dry after the reaction to obtain a porous polyethylene / carbon black composite electrode material.

3. The preparation method according to claim 2, characterized in that: In the step S1, melt spinning is performed at 140-240° C., then cooled and solidified in a water bath, and stretched 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 the step S2, the plasma etching time is 1 to 3 hours.

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

1.

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

7. The preparation method according to claim 2, characterized in that: In the step S3, the stirring speed of the cross-linking polymerization reaction is 500-1500 rpm, the reaction temperature is 60-80° C., and the reaction time is 6-12 hours.

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; The catalyst includes one of cesium carbonate, potassium carbonate or sodium carbonate; The cross-linking agent includes one of tetrafluoroterephthalonitrile, tetrafluorophthalonitrile, tetrachloroterephthalonitrile, tetrachlorophthalonitrile and hexachlorocyclotriphosphazene.

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

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