WO2016119692A1

WO2016119692A1 - Conductive filter membrane, preparation method and use thereof

Info

Publication number: WO2016119692A1
Application number: PCT/CN2016/072274
Authority: WO
Inventors: 肖辉; 吴立群; 刘铸; 庄留莹; 陈东平; 胡庭维
Original assignee: 昆明纳太科技有限公司
Priority date: 2015-01-27
Filing date: 2016-01-27
Publication date: 2016-08-04
Also published as: CN104587841A; CN104587841B

Abstract

Provided are a conductive filter membrane, a preparation method and use thereof. The conductive filter membrane is prepared mainly from a conductive material and auxiliary materials, wherein the conductive material accounts for 5-100% of the total mass of the conductive material and the auxiliary materials, and is selected from one or more of carbon nanotubes, carbon fibres with a size of 1-10 ¦Ìm, carbon nanofibres, graphene, copper nanowires, silver nanowires and conductive metal wires, and the auxiliary materials include auxiliary fibres and/or a functional filler; and the conductive filter membrane can be used for purification treatment of water. Provided is a device for purification treatment of water, comprising a power supply (206) and a shell (202). The shell (202) is provided at least one positive pole membrane (203) and at least one negative pole membrane (204) successively along the water flowing direction. Both the positive pole membrane (203) and the negative pole membrane (204) are the conductive filter membrane.

Description

Conductive filter membrane and preparation method and application thereof

Technical field

The invention relates to the technical field of materials, in particular to a conductive filter membrane and a preparation method and application thereof.

Background technique

Water is the source of life. In recent years, with the development of industry, the incident of water pollution caused by exposure to chemical plants has occurred from time to time. The water pollution caused by heavy metals, such as arsenic and lead, has become an invisible killer that harms people's health. At present, the most common water purification methods in the industry are: filtration (including nanofiltration and microfiltration), reverse osmosis, and electrochemistry. For example, in the invention patent 201310730485.5, a filter material of activated carbon or carbon nanofiber-loaded nano metal material is disclosed; the invention patent 200680036553.6 discloses a method for producing a filter core by carbon nanotube loaded carbon; the utility model patent discloses a 200780022554. A method for treating sewage by electrosorption; the above two inventions purify water by using filtration and adsorption methods to purify water. Two problems of purifying water by filtration and adsorption: 1 unit material has a limited adsorption amount, resulting in low water purification efficiency, requiring multi-stage adsorption or a large amount of adsorbent material to achieve the purpose of purifying water; 2 adsorbing bacteria and microorganisms in filtration The surface of the medium is liable to cause secondary pollution of the water body; the invention patent 200610043827.6 discloses a method for purifying water by an ultrafiltration membrane, and the invention patent 200610015370.8 discloses a method for purifying water by an ultrafiltration membrane. Simple ultrafiltration and microfiltration membranes are not able to filter out heavy metals, which is determined by the pore size of the membrane, because the filtration pore size of ultrafiltration membranes is generally 0.1 to 0.01 um (micrometers), while heavy metals such as lead Pb2+ ions With a diameter of 0.28 nm (nanometer), it is completely transparent to the pore size of the ultrafiltration membrane. Invention patent 201380002254.0 discloses a production method of reverse osmosis membrane for filtering water; there are two problems in reverse osmosis purification water: 1 reverse osmosis purification water will generate a large amount of waste water, and reverse osmosis membrane will produce 1 ton of pure water per ton. Produce 2-4 tons of wastewater; 2 reverse osmosis treatment of water will remove the beneficial sodium, potassium and zinc in the water, which is not suitable for human consumption.

There is therefore a need to develop a new type of membrane material suitable for use in water purification systems.

Summary of the invention

Based on this, it is an object of the present invention to provide a conductive filter suitable for use in a water purification process.

The specific technical solutions are as follows:

A conductive filter film is mainly prepared from a conductive material and an auxiliary material, wherein the conductive material accounts for 5-100% of the total mass of the conductive material and the auxiliary material, and the conductive material is selected from the group consisting of carbon nanotubes and has a size of 1 One or more of -10 μm of carbon fiber, carbon nanofiber, graphene, nano copper wire, nano silver wire or conductive wire, the auxiliary material comprising auxiliary fiber and/or functional filler.

In one embodiment, the auxiliary fibers are selected from one or more of the group consisting of pulp fibers, tencel fibers, ES fibers, glass fibers, polyester fibers, aramid fibers, or polytetrafluoroethylene fibers.

In one embodiment, the functional filler is selected from one or more of the group consisting of nanosilver particles, activated carbon particles, activated carbon fibers, alumina, or titanium dioxide.

In one embodiment, the conductive filter has an electrical conductivity of from 500 to 20,000 s/m.

Another object of the present invention is to provide a method of producing the above-described conductive filter.

The specific technical solutions are as follows:

The preparation method of the above conductive filter comprises the following steps:

Conducting the surface of the conductive fiber to be hydrophilic, and then mixing and dispersing with the auxiliary fiber in water, then adding the functional filler and the retention aid, and finally making and drying on the paper machine to obtain the conductive filter;

Or, one or more of carbon nanotubes, carbon nanofibers, and graphene are mixed with carbon fibers having a size of 1-10 μm and dispersed in water, and then paper-made, dried, sized, dried, and then subjected to high temperature on a paper machine. Graphitization, that is, the conductive filter;

Or, the conductive material is heated and then loaded on the pitch-based carbon fiber precursor or the polypropylene clear strand, and then pre-oxidized, carbonized, graphitized, and then spun into a carbon fiber cloth, and the functional filler is supported by electrochemical or chemical deposition. The conductive filter is obtained on a carbon fiber cloth.

In one embodiment, the retention aid is polyacrylamide.

Another object of the present invention is to provide an application of the above-described conductive filter.

The specific technical solutions are as follows:

The above-mentioned conductive filter is used in water purification treatment.

Another object of the present invention is to provide a water purification treatment apparatus.

The specific technical solutions are as follows:

A water purification treatment device comprising a power source and a casing, wherein at least one positive electrode film and at least one negative electrode film are sequentially arranged in the water flow direction, and the positive electrode film is connected to the positive electrode of the power source. The conductive filter according to any one of claims 1 to 4, wherein the negative electrode film is the conductive filter according to any one of claims 1 to 4.

In one embodiment, a separation support film is further disposed between the positive electrode film and the negative electrode film.

The principles and advantages of the present invention are as follows:

The core of the invention is a conductive filter prepared from a conductive material and an auxiliary fiber and/or a functional filler. The conductive filter has mechanical and electrical conductivity in micron-sized coarse fibers (including auxiliary fibers and carbon fibers and conductive wires in conductive materials). The skeleton, nanofibers (including carbon nanotubes, carbon nanofibers, graphene, etc.) are uniformly attached to the micron-sized crude fibers, and the functional fillers are uniformly distributed in the conductive filter membrane. The conductive filter utilizes the superior conductivity of carbon nanotubes, carbon nanofibers, carbon fibers, nano-silver wires, nano-copper wires, and metal conductive wires to purify water by electrochemical principles. The conductive filter is connected to the power source, and the oxidation reaction of the membrane of the positive electrode is utilized to remove the bacteria and organic matter in the water by using the principle of electrochemical reaction; the water for removing the organic matter and bacteria is passed through the conductive filter of the negative electrode of the power source, and the electricity is utilized. The principle of chemical reaction, the reduction of the membrane connected to the negative electrode, the heavy metal ions of copper, iron, mercury, manganese, lead, nickel, chromium to obtain electrons are reduced to metal (negative reaction has been listed). The sodium, potassium, calcium and magnesium in the water are not reduced to metal by the method because of the low potential of the standard electrode, so they remain in the water, and drinking water containing a trace amount of the above metal is beneficial to the human body. Therefore, the present invention can remove bacteria, organic matter, heavy metals in water and selectively retain certain metal ions beneficial to humans.

Cu ²⁺ +2e ^- Cu

Fe ³⁺ +3e ^- —Fe

Hg ²⁺ +2e ^- —Hg

Mn ²⁺ +2e ^- Mn

Ni ²⁺ +2e ^- -Ni

Cd ²⁺ +2e ^— Cd

The invention creatively combines the electrochemical principle and the composite nano film for the field of water purification, and utilizes the electrochemical principle that the positive electrode and the negative electrode respectively undergo oxidation reaction and oxidation reaction, and also utilizes carbon nanotubes, carbon nanofibers, carbon fibers and graphite. Excellent conductivity of olefin, nano copper and nano silver. The combination of the two can be used in the field of water purification to remove bacteria and organic matter from the water, and to remove harmful heavy metals from the water.

DRAWINGS

1 is a schematic structural view of a water purification treatment device according to Embodiment 1;

2 is a schematic cross-sectional structural view of a water purification treatment device according to Embodiment 2;

Fig. 3 is a schematic cross-sectional view showing the water purification treatment apparatus of the second embodiment.

Description of the reference signs:

201, water inlet; 202, housing; 203, positive film; 204, negative film; 205, water outlet; 206, power supply; 207, separation support film.

detailed description

The application is further elaborated below by way of examples.

Example 1

In this embodiment, a conductive filter film is mainly prepared from a conductive material and an auxiliary fiber, wherein the conductive material accounts for 15% of the total mass of the conductive material and the auxiliary fiber, and the conductive material is carbon nanofiber. The auxiliary fibers are pulp fibers and aramid fibers. The conductivity of the conductive filter was 3000 s/m.

The carbon nanofibers are oxidized in a Fenton reagent, washed, attached to a hydroxyl group, and dispersed in an aqueous solution to prepare a carbon nanofiber dispersion, and 65% of the pulp fibers and 20% of the aramid fibers are dispersed. In the water, mildly beaten, made into a slurry; the carbon nanofiber dispersion is added to the slurry, thoroughly mixed, and a polyacrylamide retention aid is added to make the hydroxylated carbon nanofibers adsorb on the pulp fiber, and then copied Type, drying, and a conductive coating.

This embodiment is a water purification treatment device as shown in FIG.

The water purification treatment device includes a power source 206 and a casing 202. The cathode membrane 203 and the anode membrane 204 are sequentially disposed in the casing along the water flow direction. The cathode membrane is a conductive membrane connected to the positive electrode of the power source, and the anode membrane is a negative electrode connected to the power source. Conductive filter. The tap water is first filtered through a filter membrane of 600 mesh, and the tap water filtered with impurities is introduced into the water purification treatment device, and sequentially passed through a conductive filter connected to the positive electrode of the power source and a conductive filter connected to the negative electrode of the power source. The water related data of the tap water that has been purified by the above steps is shown in Table 1.

Example 2

In this embodiment, a conductive filter film is prepared from a conductive material and an auxiliary material (auxiliary fiber and functional filler), the conductive material accounts for 50% of the total mass of the conductive material and the auxiliary material, and the conductive material is nanometer. Copper wire, graphene and carbon fiber, the auxiliary fiber is a tencel fiber. The conductivity of the conductive filter was 8000 s/m.

5% of graphene is oxidized in Fenton's reagent, washed, attached to a hydroxyl group, and dispersed in an aqueous solution to prepare a graphene dispersion; 50% of tencel fiber, 35% of carbon fiber, and 10 % of the nano copper wire is dispersed in water and stirred to form a slurry; the graphene dispersion is added to the slurry, thoroughly mixed, and a polyacrylamide retention aid is added to cause the hydroxylated graphene to be adsorbed on the pulp fiber, and then The type of copying and drying, that is, the conductive filter film is used for the positive and negative electrodes.

This embodiment is a water purification treatment device as shown in FIGS. 2 and 3.

The water purification treatment device comprises a power source 206 and a casing 202. The cathode membrane 203, the separation support membrane 207 and the two anode membranes 204 are sequentially arranged in the water flow direction; the tap water is first filtered through a filter membrane of 600 mesh, and the tap water of the impurities is filtered. Enter the water purification treatment device, and then pass through the conductive filter connected to the positive electrode of the power supply and the conductive filter connected to the negative electrode of the power supply. The water related data after the tap water is purified by the above steps is shown in Table 1.

Example 3

In this embodiment, a conductive filter film is prepared by using a conductive material and a functional filler. The conductive material accounts for 90% of the total mass of the conductive material and the functional filler, the conductive material is carbon nanotubes and carbon fibers, and the functional filler is titanium dioxide. The conductive filter has an electric conductivity of 20,000 s/m and is used as a positive electrode film in a water purification treatment device.

Another conductive filter connected to the negative electrode: the conductive material accounts for 80% of the total mass of the conductive material and the auxiliary fiber, the conductive material is carbon nanotubes and carbon nanofibers, and the auxiliary fibers are glass fiber and polyester fiber. The conductivity of the conductive filter was 10,000 s/m.

Positive electrode film: The carbon nanotubes are heated to 180 degrees Celsius, and then the pitch-based carbon fiber precursor is passed through the heated carbon nanotubes, cooled, and the whole process is under nitrogen protection. The pitch-based carbon fiber precursor with carbon nanotubes adhered thereto is pre-oxidized for 2 hours under air condition at 200 ° C, and then treated with 500 ° C for 2 min, 800 ° C for 1 min and 1800 ° C for 30 s to obtain carbon nanotubes. Carbon fiber, and then the carbon fiber is spun into a plain carbon fiber cloth; the carbon fiber is arranged in a titanium tetrachloride solution, a layer of TiO2 is electrodeposited, washed, dried, and then sintered at 450 ° C for 1 hour under nitrogen gas to obtain a positive electrode. The conductive membrane of the membrane.

Negative electrode film: 65% carbon nanotubes and 15% carbon nanofibers are oxidized in Fenton reagent, washed, attached to hydroxyl groups, dispersed in an aqueous solution to form carbon nanotubes and carbon nanofibers dispersed. Liquid; disperse 10% glass fiber and 10% polyester fiber in water, stir to prepare a slurry; add carbon nanofibers and carbon nanotube dispersion into the slurry, mix well, add polyacrylamide retention aid, and then carry out It is made into a type and dried, and a conductive filter is obtained for the negative electrode film.

In the embodiment, a water purification treatment device includes a power source and a casing, and the cathode casing, the separation separator, and the anode membrane are sequentially disposed in the water flow direction. The tap water is first filtered through a filter membrane of 600 mesh, and the tap water filtered by the impurities enters the water purification treatment device, and then passes through the conductive filter connected to the positive electrode of the power source and the conductive filter connected to the negative electrode of the power source. The data of the tap water purified by the above steps is shown in Table 1. .

Example 4

In this embodiment, a conductive filter film is prepared by using a conductive material and a functional filler, wherein the conductive material accounts for 80% of the total mass of the conductive material and the functional filler, and the conductive material is carbon nanofiber and carbon nanometer. Tube, carbon fiber, functional filler is nano silver. The conductivity of the conductive filter is 16000 s/m, The water purification treatment device serves as a positive electrode membrane.

Another conductive filter connected to the negative electrode: the conductive material accounts for 10% of the total mass of the conductive material and the auxiliary material (auxiliary fiber and functional filler), the conductive material is carbon nanofiber, the functional filler is activated carbon, and the auxiliary fiber is aromatic Polyester and polyester fibers. The conductivity of the conductive filter was 800 s/m.

Positive electrode film: Carbon fiber, carbon nanofiber, and carbon nanotube are mixed and formed into paper at a ratio of 7:2:1, phenol resin (viscosity 23mPa s) is immersed, dried, and cured at 160 ° C for 20 minutes, and then Under the protection of inert gas, the temperature was raised to 460 ° C for 1 hour, and then heated to 900 ° C for 1 hour to obtain carbon fiber paper. The carbon fiber paper is electrochemically activated in phosphoric acid, then washed, placed in SnCl ₂ and PdCl ₂ for sensitization treatment, washed, and the treated paper is placed in a 0.05 mol/L silver ammonia solution, and a reducing agent is added. Formaldehyde, cleaning and drying to produce a conductive filter containing nano-silver.

Negative electrode film: carbon nanofibers, which account for 10% of the total mass of the conductive filter, are oxidized in Fenton's reagent, washed, attached to a hydroxyl group, and dispersed in an aqueous solution to prepare a carbon nanofiber dispersion; 50% The aramid fiber and 35% of the polyester fiber are dispersed in water, stirred, and 5% activated carbon is added to prepare a slurry; the carbon nanofiber dispersion is added to the slurry, thoroughly mixed, and the polyacrylamide retention aid is added, and then It is made into a copying type and dried to obtain a conductive filter for the negative electrode film.

In the embodiment, a water purification treatment device includes a power source and a casing, and the cathode casing, the separation separator, and the anode membrane are sequentially disposed in the casing along the water flow direction. The tap water is first filtered through a two-stage 300-mesh filter membrane. The tap water after filtering the impurities enters the water purification treatment device, and sequentially passes through the conductive filter connected to the positive electrode of the power source and the conductive filter connected to the negative electrode of the power source. The data of the tap water purified by the above steps is shown in the table. 1.

Example 5

In this embodiment, a conductive filter film is prepared from a conductive material and an auxiliary material (auxiliary fiber and functional filler), the conductive material accounts for 75% of the total mass of the conductive material and the auxiliary material, and the conductive material is nanometer. Silver wire, graphene, functional filler is nano silver particles, and the auxiliary fiber is ES fiber. The conductive filter has an electric conductivity of 20,000 s/m and is used as a positive electrode film in a water purification treatment device.

Another conductive filter connected to the negative electrode: conductive material accounts for conductive materials and auxiliary materials (auxiliary fibers and work The filler can be 5% of the total mass, the conductive material is carbon nanofiber, the functional filler is activated carbon, and the auxiliary fiber is polytetrafluoroethylene and polyester fiber. The conductivity of the conductive filter was 500 s/m.

Positive electrode film: 25% graphene is oxidized in Fenton reagent, washed, attached to a hydroxyl group, dispersed in an aqueous solution to prepare a graphene dispersion; 20% ES fiber and 50% nanometer The silver wire is dispersed in water and stirred to form a slurry; the graphene dispersion is added to the slurry, thoroughly mixed, a polyacrylamide retention aid is added, and then the form is applied, and the polyurethane containing nano silver (5%) is applied. Glue, dried and cured, obtained a conductive filter for the positive film.

Negative electrode film: 5% carbon nanofibers were oxidized in Fenton's reagent, washed, attached to a hydroxyl group, dispersed in an aqueous solution to prepare a carbon nanofiber dispersion; 50% polytetrafluoroethylene fiber And 35% of the polyester fiber is dispersed in water, stirred, and 10% activated carbon is added to prepare a slurry; the carbon nanofiber dispersion is added to the slurry, thoroughly mixed, polyacrylamide retention aid is added, and then the type is produced. , drying, a conductive coating for the anode film.

Example 6

In this embodiment, a conductive filter film is prepared from a conductive material and an auxiliary material (auxiliary fiber and a functional filler), the conductive material accounts for 90% of the total mass of the conductive material and the auxiliary material, and the conductive material is carbon fiber. The carbon nanotubes, the functional filler are nano silver particles, and the auxiliary fibers are glass fibers. The conductive filter has an electric conductivity of 20,000 s/m and is used as a positive electrode film in a water purification treatment device.

Another conductive filter connected to the negative electrode: the conductive material accounts for 80% of the total mass of the conductive material and the auxiliary fiber, the conductive material is carbon nanotubes and carbon fibers, and the auxiliary fibers are glass fibers and polyester fibers. The conductivity of the conductive filter was 15,000 s/m.

Positive electrode film: 10% carbon nanotubes were oxidized in Fenton's reagent, washed, attached to a hydroxyl group, dispersed in an aqueous solution to prepare a carbon nanotube dispersion, 8% glass fiber and 80% The carbon fiber is dispersed in water, adjusted to a pH of 3, and stirred to form a slurry; the carbon nanotube dispersion is added to the slurry, thoroughly mixed, 2% of the nano silver particles are added, the polyacrylamide retention aid is added, and then It is made into a type, dried, and has a conductive filter for the positive electrode film.

Negative electrode film: 10% of carbon nanotubes are oxidized in Fenton's reagent, washed, attached to a hydroxyl group, dispersed in an aqueous solution to form a carbon nanotube dispersion; 10% glass fiber, 10% The polyester fiber and 70% carbon fiber are dispersed in water and stirred to form a slurry; the carbon nanotube dispersion is added to the slurry, thoroughly mixed, and the polyacrylamide retention aid is added, and then the shape is formed and dried, that is, A conductive filter is used for the negative electrode film.

In this embodiment, a water purification treatment device includes a power source and a casing, and the cathode casing, the separation separator, and the anode membrane are sequentially disposed in the casing along the water flow direction. The tap water is first filtered through a first-stage 600-mesh filter membrane, and the tap water after filtering the impurities enters the water purification treatment device, and sequentially passes through the conductive filter connected to the positive electrode of the power source and the conductive filter connected to the negative electrode of the power source, and the data of the tap water purified by the above steps is shown in the table. 1.

Table 1

It can be seen from the table that Examples 3, 5, and 6 have excellent antibacterial properties due to the fact that the positive electrode film contains a large amount of nano silver. Although the nano silver was contained in Example 4, the flow rate was too fast, resulting in a poor processing due to the sparse structure. For the removal of heavy metals, mainly the role of the negative electrode, in several examples, there is a certain removal effect on heavy metals, but the effect is best in Example 6.

The above-mentioned embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A conductive filter film is characterized in that the conductive filter film is mainly prepared from a conductive material and an auxiliary material, the conductive material accounts for 5-100% of the total mass of the conductive material and the auxiliary material, and the conductive material is selected from the group consisting of carbon nanotubes. One or more of carbon fibers, carbon nanofibers, graphene, nano copper wires, nano silver wires or conductive wires having a size of 1-10 μm, the auxiliary materials including auxiliary fibers and/or functional fillers.
The conductive filter according to claim 1, wherein the auxiliary fiber is selected from the group consisting of pulp fibers, tencel fibers, ES fibers, glass fibers, polyester fibers, aramid fibers, and polytetrafluoroethylene fibers. Or several.
The conductive filter according to claim 1, wherein the functional filler is one or more selected from the group consisting of nanosilver particles, activated carbon particles, activated carbon fibers, alumina or titania.
The conductive filter according to any one of claims 1 to 3, wherein the conductive filter has an electric conductivity of 500 to 20,000 s/m.
The method for preparing a conductive filter according to any one of claims 1 to 4, comprising the steps of:

The conductive fiber is subjected to surface hydrophilic treatment, mixed with the auxiliary fiber and dispersed in water, and then added with a functional filler and a retention aid, and finally formed and dried on a paper machine to obtain the conductive filter;

Or, one or more of carbon nanotubes, carbon nanofibers, and graphene are mixed with carbon fibers having a size of 1-10 μm and dispersed in water, and then paper-made, dried, sized, dried, and then subjected to high temperature on a paper machine. Graphitization, that is, the conductive filter;

Or, the conductive material is heated and then loaded on the pitch-based carbon fiber precursor or the polypropylene clear strand, and then pre-oxidized, carbonized, graphitized, and then spun into a carbon fiber cloth, and the functional filler is supported by electrochemical or chemical deposition methods. The conductive fiber membrane is obtained on the carbon fiber cloth.
The method according to claim 5, wherein the retention aid is polyacrylamide.
Use of the conductive filter according to any one of claims 1 to 4 in a water purification treatment.
A water purification treatment device includes a power source and a casing, wherein at least one positive electrode film and at least one negative electrode film are sequentially disposed in the casing along a water flow direction, and the positive electrode film is connected to the positive electrode of the power source. The conductive filter according to any one of claims 1 to 4, wherein the negative electrode film is the conductive filter according to any one of claims 1 to 4, which is connected to the negative electrode of the power source.
The water purification treatment apparatus according to claim 8, wherein a separation support film is further provided between the positive electrode film and the negative electrode film.