阅读说明：本技术 一种纳米锥结构聚吡咯/金属网多孔过滤膜及其制备方法与应用 (Polypyrrole/metal mesh porous filtering membrane with nanocone structure and preparation method and application thereof ) 是由 于鹏 黄怡萱 宁成云 王珍高 刘广宇 李玮 周蕾 范磊 张珂嘉 冉合迎 于 2020-04-17 设计创作，主要内容包括：本发明公开了一种纳米锥结构聚吡咯/金属网多孔过滤膜及其制备方法与应用。所述方法为：(1)金属滤网表面喷砂处理,在滤网表面制备具有微岛和微沟壑的结构；(2)通过电化学方法在金属网表面沉积平滑聚吡咯膜层；(3)在聚吡咯膜层表面电化学沉积纳米锥结构的聚吡咯。该功能化的复合滤膜可以实现超快的油水分离,可以分离各种污水,同时该功能膜具有很好的机械稳定性和抗腐蚀特性,可以反复使用。(The invention discloses a polypyrrole/metal mesh porous filtering membrane with a nanocone structure and a preparation method and application thereof. The method comprises the following steps: (1) performing sand blasting treatment on the surface of the metal filter screen, and preparing a structure with a micro island and micro gullies on the surface of the metal filter screen; (2) depositing a smooth polypyrrole film layer on the surface of the metal mesh by an electrochemical method; (3) and electrochemically depositing polypyrrole with a nano cone structure on the surface of the polypyrrole film layer. The functional composite filter membrane can realize ultra-fast oil-water separation and separate various kinds of sewage, and meanwhile, the functional membrane has good mechanical stability and corrosion resistance and can be used repeatedly.)

1. A preparation method of a polypyrrole/metal mesh porous filtering membrane with a nanocone structure is characterized by comprising the following steps:

(1) performing sand blasting treatment on the surface of the metal filter screen to enable the metal filter screen to have a micro-island and micro-gully structure, so as to obtain a sand blasting metal filter screen;

(2) selecting a three-electrode mode, taking conductive metal as a counter electrode, taking the sand blasting metal filter screen in the step (1) as a working electrode, taking an electrolyte as a salt solution containing pyrrole, and controlling an electrochemical reaction by adopting a constant voltage method to smoothly deposit polypyrrole on the surface of the sand blasting metal filter screen;

(3) and (3) selecting a three-electrode mode, using conductive metal as a counter electrode, using the sand blasting metal filter screen deposited with smooth polypyrrole in the step (2) as a working electrode, using an electrolyte as a phosphate buffer solution containing pyrrole and naphthalenesulfonic acid, and controlling an electrochemical reaction by adopting a constant current method to deposit the polypyrrole with a nanocone structure on the surface of the smooth polypyrrole to obtain the polypyrrole/metal mesh porous filtering membrane with the nanocone structure.

2. The preparation method of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure according to claim 1, wherein the current density of the electrochemical reaction in the step (3) is 2.0-4.0 mA/cm²The time of the electrochemical reaction is 25 toFor 70 minutes.

3. The preparation method of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure according to claim 1, wherein the concentration of pyrrole in the electrolyte in the step (3) is 0.1-0.3 mol/L, and the concentration of naphthalene sulfonic acid is 0.005-0.02 mol/L.

4. The preparation method of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure according to claim 1, wherein the electrolyte in step (2) is a hydrochloric acid solution or a potassium chloride solution containing pyrrole, wherein the concentration of chloride ions is 0.1-0.3 mol/L, and the concentration of pyrrole in the electrolyte is 0.1-0.3 mol/L.

5. The preparation method of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure according to claim 1, wherein the voltage of the electrochemical reaction in the step (2) is 0.7-1.1V; the time of the electrochemical reaction is 20-120 seconds.

6. The preparation method of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure according to any one of claims 1 to 5, characterized in that the sand used in the sand blasting treatment in the step (1) is at least one of corundum, silicon carbide and quartz sand; the size of the sand is 60-300 meshes; the sand blasting pressure of the sand blasting treatment is 0.3-0.7 MPa, and the sand blasting treatment time is 1-3 minutes.

7. The preparation method of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure according to any one of claims 1 to 5, wherein the metal filtering mesh in step (1) is one of titanium, copper and stainless steel metal filtering meshes; the size of the metal filter screen is 200-400 meshes; and (3) the conductive metal in the steps (2) and (3) is a platinum electrode and a copper electrode.

8. The preparation method of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure according to any one of claims 1 to 5, wherein the pH of the phosphate buffer solution containing pyrrole and naphthalenesulfonic acid in step (3) is 6.2 to 7.2.

9. A polypyrrole/metal mesh porous filtering membrane with a nano cone structure prepared by the method of any one of claims 1 to 8.

10. The application of the polypyrrole/metal mesh porous filtering membrane with the nanocone structure in the oil-water separation in the claim 9.

Technical Field

The invention belongs to the technical field of sewage treatment functional membrane manufacturing, and particularly relates to a polypyrrole/metal mesh porous filtering membrane with a nanocone structure, and a preparation method and application thereof.

Background

In the exploitation and transportation of oil, oil leakage is a common phenomenon. The petroleum leakage can cause serious water pollution and threaten the ecological environment. The method has various methods aiming at the oil stain treatment of the water area, and comprises an oil absorption material adsorption method, a functional membrane separation method, a dispersant degradation method and the like. The functional membrane separation method has the advantages of convenience, rapidness, low cost, environmental protection, low energy consumption and the like, so that the method is concerned by many researchers. Super-hydrophobic/super-hydrophilic materials are widely used as oil-water separation membranes, which can selectively adsorb oil phase/water phase to achieve oil-water separation effect. The research is that magnesium alloy is taken as a substrate, the surface of the magnesium alloy is respectively subjected to pretreatment, low-fluorine activation and ionic solution electrodeposition treatment to prepare an aluminum film, and then a Czochralski method is used for coating the surface of the aluminum film with nano SiO with a super-hydrophobic function₂Particles, which require multiple operations to achieve superhydrophobic effect; there are also researchers depositing polymer microspheres on a substrate to obtain a super-hydrophobic separation membrane, but the bonding of the coating to the substrate is not stable enough and is easy to fall off. In addition, some researchers prepare the ABS/ZnO nano composite membrane by an electrostatic spinning technology to be used as a functional membrane for oil-water separation, but the technology is difficult to realize large-area preparation, the preparation cost is high, and the reusability of the material is poor. Meanwhile, the existing technology for preparing the oil-water separation membrane is difficult to further improve the separation rate.

Therefore, based on the preparation difficulty and the use limitation of the current oil-water separation functional membrane, the polypyrrole/metal mesh composite functional membrane with the nano structure is prepared through convenient, controllable and environment-friendly electrochemistry, and the rapid oil-water separation function is realized. The polypyrrole is a conductive polymer with high conductivity, easy synthesis and good environmental stability, and the polypyrrole film can improve the corrosion potential of metal and protect the metal from corrosion. Patent 200710037333.1 discloses a method for preparing a wholly hydrophobic polypyrrole film: glass is used as a substrate, a segmented copolymer film is coated on the surface of the glass, then a polypyrrole thin layer is selectively deposited on the surface of the film, and the polypyrrole is controlled to have hydrophobicity in an oxidation state and a reduction state, so that an oil-water separation function is realized. There are currently few techniques for using polypyrrole to improve filtration membranes for oil-water separation.

Disclosure of Invention

In order to solve the defects and shortcomings of the prior art, the invention aims to provide a preparation method of a polypyrrole/metal mesh porous filtering membrane with a nanocone structure, wherein a polypyrrole nanocone is grafted on the surface of a metal mesh through sand blasting and an electrochemical method. Firstly, constructing islands with micron structures on the surface of a titanium mesh through sand blasting, then depositing a smooth polypyrrole film layer on the surface of a metal mesh through an electrochemical method, and finally electrochemically depositing polypyrrole with a nanocone structure on the surface of the polypyrrole film layer.

The invention also aims to provide the polypyrrole/metal mesh porous filtering membrane with the nano-cone structure, which is prepared by the method, the functionalized composite filtering membrane can realize ultra-fast oil-water separation and can separate various sewages, such as alkaline sewage, acid-washing sewage, sewage infected by bacteria and the like, and meanwhile, the functional membrane has good mechanical stability and corrosion resistance and can be repeatedly used.

The invention further aims to provide application of the polypyrrole/metal mesh porous filtering membrane with the nano cone structure in oil-water separation.

The purpose of the invention is realized by the following technical scheme:

a preparation method of a polypyrrole/metal mesh porous filtering membrane with a nanocone structure comprises the following steps:

(1) performing sand blasting treatment on the surface of the metal filter screen to enable the metal filter screen to have a micro-island and micro-gully structure, so as to obtain a sand blasting metal filter screen;

(2) selecting a three-electrode mode, taking conductive metal as a counter electrode, taking the sand blasting metal filter screen in the step (1) as a working electrode, taking an electrolyte as a salt solution containing pyrrole, and controlling an electrochemical reaction by adopting a constant voltage method to smoothly deposit polypyrrole on the surface of the sand blasting metal filter screen;

(3) and (3) selecting a three-electrode mode, using conductive metal as a counter electrode, using the sand blasting metal filter screen deposited with smooth polypyrrole in the step (2) as a working electrode, using an electrolyte as a phosphate buffer solution containing pyrrole and naphthalenesulfonic acid, and controlling an electrochemical reaction by adopting a constant current method to deposit the polypyrrole with a nanocone structure on the surface of the smooth polypyrrole to obtain the polypyrrole/metal mesh porous filtering membrane with the nanocone structure.

Preferably, the metal screen in step (1) is one of titanium, copper and stainless steel metal screen.

Preferably, the size of the metal filter screen in the step (1) is 200-400 meshes.

Preferably, before the sand blasting treatment, the metal filter screen in the step (1) needs to be cleaned by deionized water, absolute ethyl alcohol and acetone, and then the oil stain and the oxide layer on the surface of the metal filter screen are removed by acid cleaning.

Preferably, the sand used in the sand blasting treatment in the step (1) is at least one of corundum, silicon carbide and quartz sand; the size of the sand is 60-300 meshes, and more preferably 60-200 meshes; the sand blasting pressure of the sand blasting treatment is 0.3-0.7 MPa, and the sand blasting treatment time is 1-3 minutes.

Preferably, the electrolyte in the step (2) is a hydrochloric acid solution or a potassium chloride solution containing pyrrole, wherein the concentration of chloride ions is 0.1-0.3 mol/L, and more preferably 0.25 mol/L; the concentration of pyrrole in the electrolyte is 0.1-0.3 mol/L, and more preferably 0.2 mol/L.

Preferably, the voltage of the electrochemical reaction in the step (2) is 0.7-1.1V; the time of the electrochemical reaction is 20-120 seconds, and more preferably 20 seconds.

Preferably, the conductive metal in steps (2) and (3) is both platinum electrode and copper electrode.

Preferably, the concentration of pyrrole in the electrolyte in the step (3) is 0.1-0.3 mol/L, more preferably 0.2mol/L, and the concentration of naphthalenesulfonic acid is 0.005-0.02 mol/L, more preferably 0.01 mol/L.

Preferably, the current density of the electrochemical reaction in the step (3) is 2.0-4.0 mA/cm²More preferably 3.6mA/cm²(ii) a The time of the electrochemical reaction is 25-70 minutes, and more preferably 40 minutes.

Preferably, the pH of the phosphate buffer solution containing pyrrole and naphthalenesulfonic acid in step (3) is 6.2-7.2, preferably 6.8.

The polypyrrole/metal mesh porous filtering membrane with the nano cone structure is prepared by the method.

The application of the polypyrrole/metal mesh porous filtering membrane with the nano-cone structure in oil-water separation is provided.

The application the polypyrrole/metal mesh porous filtering membrane with the nano cone structure can realize rapid oil-water separation.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) polypyrrole with a nano-cone structure is constructed on a conductive base material by adopting a pollution-free rapid controllable electrochemical method.

(2) The titanium net/smooth polypyrrole/nanocone structure composite filter screen realizes the function of rapid oil-water separation.

(3) The titanium net/smooth polypyrrole/nanocone structure composite filter screen can be reused for many times without pollutant adhesion.

Drawings

FIG. 1 is a schematic diagram of a preparation process of a polypyrrole/metal mesh porous filter membrane with a nanocone structure according to the present application.

FIG. 2 is an electron microscope photograph of the polypyrrole/metal mesh porous filter membrane of the nano-cone structure obtained by the reaction for 30 minutes in example 1, wherein the electron microscope photograph of different observation times is from left to right.

FIG. 3 is a diagram showing a porous filter membrane used for oil-water separation in example 1, which has a reaction time of 30 minutes.

FIG. 4 is a graph showing the relationship between the reaction time and the separation rate in example 1.

Fig. 5 is a microscope picture of the surface of the sample prepared in comparative example 3 on which only smooth-structured polypyrrole was deposited.

FIG. 6 shows the separation efficiency of the membrane used in the oil-water separation experiment in example 4.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

Those who do not specify specific conditions in the examples of the present invention follow conventional conditions or conditions recommended by the manufacturer. The raw materials, reagents and the like which are not indicated for manufacturers are all conventional products which can be obtained by commercial purchase.

The sand blasting machine used in the embodiment of the application is purchased from Liangwei Automation equipment Co., Ltd, Guangzhou, and has the model number of 9080 AS-3A.