CN215138695U

CN215138695U - Filtering membrane based on silver ion antibacterial function

Info

Publication number: CN215138695U
Application number: CN202121026522.0U
Authority: CN
Inventors: 郭飞; 陈佳明; 蔡景成
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2021-12-14
Anticipated expiration: 2031-05-14

Abstract

The utility model belongs to the water treatment field involves a filtration membrane based on antibacterial function of silver ion. The utility model provides a filtration membrane of antibacterial function includes the functional layer of two supporting layers and centre. The supporting layer is a non-woven fabric which plays a role in supporting and protecting; the functional layer is a fiber film with nano silver particles attached to fibers. The nano-silver particles and the dispersing agent are added into the electrostatic spinning solution for blending, or silver nitrate and a reducing agent are sprayed in the electrostatic spinning process, and the silver nitrate performs a reduction reaction to enable a large number of nano-silver particles to be attached to the surface of the fiber. The prepared functional layer containing the nano silver particles can release silver ions with a sterilization effect during filtering, and the functions of sterilization and bacteriostasis are achieved. The utility model provides an antibacterial filtration membrane still has can directly use, and the advantage of portable replacement can extensively be used for fields such as family's drinking water, field exploration, fruit juice concentration of disinfecting.

Description

Filtering membrane based on silver ion antibacterial function

Technical Field

The utility model belongs to the technical field of water treatment, a compound filtration membrane based on antibacterial function of silver ion is related to.

Background

Membrane filtration is an important filtration means in the field of water treatment. Can be classified into microfiltration, ultrafiltration, nanofiltration membrane and the like according to the treatment scale; and flat membrane, hollow fiber membrane, etc. according to the kind of membrane. Although different filter membrane types correspond to different treatment objects and treatment modes, more filter membranes are still used in the fields of industrial sewage concentration, seawater desalination and the like, have the functions of macroscopic isolation, concentration and filtration, and usually need to be equipped with external equipment. In the filtering application process, the phenomenon of blockage caused by the enrichment of a large amount of bacteria and pollutants on the surface of the filter membrane often occurs, so that the filtering rate is reduced, and the drinking safety is influenced. Along with the improvement of the social requirement on the quality of drinking water and the safety requirement of the food industry, a filtering membrane which is convenient to use and safer in the quality of produced water is needed. Therefore, based on the broad-spectrum bacteriostasis of silver, people add nano silver to release silver ions to destroy proteins in bacterial cell membranes, cause disorder of nutrient exchange inside and outside bacteria, enter the inside of the bacteria to inactivate partial enzymes and proteins, even interfere with the expression of DNA, and realize bacteriostasis. However, most of the existing bacteriostatic filter membranes adopt a coating method or are added with bacteriostatic agents randomly, so that the bactericidal effect and the filtering effect of the existing bacteriostatic filter membranes in practical application are limited by the mechanical properties and the filtering properties of a coating structure and a membrane material, and the effect is not obvious; and is difficult to produce in batches and inconvenient to use. Therefore, the utility model discloses introduce the electrostatic spinning technique, provided an utilize the bactericidal nature of silver ion to realize antibacterial composite filtration membrane. The antibacterial composite filtering membrane can be widely applied to the fields of household drinking water, field exploration, fruit juice sterilization and concentration and the like.

SUMMERY OF THE UTILITY MODEL

In order to overcome the problems in the prior art, the utility model aims to provide a filtering membrane based on silver ion antibacterial function and a preparation method thereof.

The technical scheme of the utility model is that:

a filtering membrane based on a silver ion antibacterial function comprises two supporting layers and a middle functional layer; the functional layer is a fiber film with nano silver particles attached to fibers, multiple layers of the fiber film can be superposed and compounded with each other, and the support layer is a non-woven fabric or various fiber films with a support and protection effect.

The filtering membrane based on the silver ion antibacterial function only contains a single functional layer, and the quantitative ratio is 45 +/-3 g/m²(ii) a The flow rate is more than 25L/m²The thickness of the filter membrane is 200-300 mu m;

the functional layer fiber membrane comprises a fiber membrane made of one of polyacrylonitrile, polypropylene, polyhydroxy polymer, polyamide, polyvinylidene fluoride and hydrophilic modified materials thereof, and has the property of resisting chemical reagents; the fiber diameter of the fiber membrane is 0.01-1 μm, the pore diameter is 0.11-10 μm, the thickness of a single layer is 10-100 μm, and the porosity is more than 20%;

the diameter of the nano silver particles attached to the functional layer fiber membrane is 50 nm-5 mu m.

Furthermore, the fiber film is adhered with nano silver particles and titanium dioxide and silicon dioxide particles with the diameter of 50 nm-50 mu m, so that the antibacterial performance and the whiteness are further improved.

The material of the supporting layer comprises a fiber film prepared from one or more than two of polypropylene, polyethylene terephthalate and polyvinylidene fluoride, or a finished non-woven fabric; has good mechanical property, acid and alkali resistance, stable chemical property and no toxicity. Easy to wash and fold, and is not easy to adsorb suspended particles in the air. The aperture of the supporting layer is larger than that of the functional layer, the range of the aperture is 1-50 mu m, the porosity is larger than 20%, the apparent contact angle is 80-160 degrees, the single-layer thickness is smaller than 200 mu m, and the hydraulic penetration pressure is small.

The preparation method of the filtering membrane based on the silver ion bacteriostasis function comprises the following steps:

step 1, preparing a solution;

the solute of the spinning solution comprises 8-18 wt% of polyacrylonitrile, 8-18 wt% of dispersant polyvinylpyrrolidone and 2-8 wt% of nano silver particles, the particle size is less than 500nm, and the solvent is a dimethylformamide solution or a mixed solution of a dimethylacetamide solution and acetone; polyacrylonitrile is the main component of the fiber, and polyvinylpyrrolidone is used as a dispersing agent to uniformly disperse nano silver;

step 2, electrostatic spinning;

the applied positive voltage is + 12-20 kV, the negative voltage is-3 to-5 kV, the receiving distance is 10-50 cm, and the transmission speed of the supporting layer is 0.5-5 m/min;

step 3, multilayer compounding: and the functional layer is wrapped between the two support layers by adopting a hot pressing method.

Further, the dispersant in the solute in the step 1 is one of polyethylene glycol and sodium dodecyl sulfate.

The solution is required to be filled in a closed bottle, air and water are isolated, then a magnetic-driven stirrer is put in the closed bottle filled with the solution, and stirring is carried out under the heating condition of water bath until the solution is clear and transparent. Preferably, the heating temperature is 55-65 ℃, and the stirring time is longer than 12 hours.

The preparation method of the filtering membrane based on the silver ion bacteriostasis function, the second scheme, comprises the following steps:

step 1, preparing a solution;

the spinning solution only contains polyacrylonitrile and a solvent, and the solvent is a dimethylformamide solution or a mixed solution of a dimethylacetamide solution and acetone;

step 2, carrying out electrostatic spinning,

spraying silver-containing salt solution containing nano silver particles or silver nitrate and silver perchlorate as well as a reducing agent and a dispersing agent thereof in the electrostatic spinning process; the spraying solution is one of 0.001-1 mol/L silver nitrate solution, 0.001-1 mol/L trisodium citrate solution as a reducing agent, a mixed solution of hydrogen peroxide and ammonia water and dimethylformamide; the dispersing agent comprises one or more than two of polyvinylpyrrolidone, polyethylene glycol and lauryl sodium sulfate, and the concentration is 0.01-1 mol/L. The spraying process is carried out under the irradiation of ultraviolet rays with the wavelength of more than 365nm, and the reduction of silver salts such as silver nitrate and the like is assisted;

Preferably, the hot pressing temperature is 60-80 ℃, and the pressure is 0.4-0.8 MPa. The functional layer includes but is not limited to a plurality of functional layers which are superposed or introduced with films made of cotton and nylon for further compounding.

The antibacterial composite filtering membrane can be widely applied to the fields of household drinking water, field exploration, fruit juice sterilization and concentration and the like.

The utility model discloses an effect does:

1. the utility model discloses the method that uses nano-silver granule blending, nano-silver granule spraying, reduction silver nitrate solution has attached the nano-silver granule that can release silver ion on the fibre of filtering function layer, thereby can release silver ion in the water filtration link and disinfect and realize bacteriostatic, obtain the drinking water of more favourable health.

2. The utility model has light weight, is convenient to carry and replace, and can be widely applied to family water purification and field exploration to obtain fresh water.

3. The utility model discloses when the antibacterial bacteriostasis of innovative increase filtration membrane, it is big also to have kept the water yield, good filtration efficiency such as the thing that can dissolve to aquatic part, suspended solid. Because of having good mechanical properties, collapsible, compound, can be compatible with most current purifier, realize high-efficient replacement to filtration membrane wherein.

Drawings

FIG. 1 is an overall structure diagram of a high-efficiency bacteriostatic filtering membrane.

Fig. 2 is an electron microscope image of a functional layer with nano silver particles added to the surface.

Fig. 3 is a schematic view of an electrospinning method for preparing a functional layer.

In the figure: 1, a solution tank; 2, a needle-free spinning rotating shaft; 3, high-voltage electrostatic generator anode; 4 functional layer fiber yarn; 5 silver-containing salt solution and reducing agent; 6 an ultraviolet lamp; 7, a hot-pressing device; 8, a negative electrode of the high-voltage electrostatic generator; 9 a negative plate; 10 support layers.

FIG. 4 is a schematic view showing the assembly of a multi-layered filtering membrane of a household water purifier.

FIG. 5 is a schematic view of a filter membrane in direct use in the field.

Detailed Description

In order to more clearly illustrate the objects, technical solutions and advantages of the present invention, the present invention will be described in detail with reference to specific embodiments. It should be understood that the examples are given for illustration only and are not intended to limit the scope of the invention.

Example 1 (preparation)

Firstly, the solution used for electrostatic spinning needs to be prepared: the solute of the solution comprises 12 wt% of polyacrylonitrile, 12 wt% of polyvinylpyrrolidone and 8 wt% of nano silver particles with the particle size of 50nm, and the solvent comprises a dimethylformamide solution and an acetone solution in a mass ratio of 95: 5. The polyvinylpyrrolidone is used as a dispersing agent to uniformly disperse the nano silver in the solution. The prepared solution needs to be filled in a closed bottle, air and water are isolated, then a magnetic stirrer is put into the closed bottle filled with the solution, and the solution is stirred for more than 12 hours under the heating of water bath at 60 ℃ until the solution is clear and transparent. In the electrospinning, the solution was taken out and poured into the solution tank 1.

The rotating shaft 2 rotates at a high speed under the high-voltage static of +15kV provided by the high-voltage static generator 3, the solution forms a liquid film on the surface of the rotating shaft, liquid drops are thrown out under centrifugal force and are attracted by a negative plate 9 of-4 kV static provided by the high-voltage static generator 8, the solvent in the liquid drops is evaporated in the air, and the solute forms fiber filaments and falls on a non-woven fabric supporting layer 10 made of polypropylene. The receiving distance of the supporting layer is 20cm, and the transmission speed is 1 m/min. The diameter of the functional layer fiber filaments attached to the supporting layer is 0.01-1 mu m, and the functional layer fiber filaments are mutually interwoven on the surface of the supporting layer to form a fiber membrane with the thickness of 30 mu m, the pore diameter of 1-10 mu m and the porosity of more than 80%.

The device 7 is hot-pressed by two heating rollers, and another polypropylene non-woven fabric support layer is covered on the previously formed functional layer containing the nano silver particles at the hot-pressing temperature of 70 ℃ and the pressure of 0.6MPa, so that the two support layers are tightly attached to the functional layer.

Example 2

The electrospinning solution may also contain 12 wt% of polyacrylonitrile and a solvent consisting of dimethylformamide and acetone in a mass ratio of 95:5, and the solution preparation method and electrospinning parameters are the same as those of example 1. Adding a program in the electrostatic spinning link:

in the electrostatic spinning process, a solution containing silver salts such as nano silver particles or silver nitrate is sprayed by the device 5. The spraying solution is a mixture of 0.1mol/L silver nitrate solution, ammonia water and hydrogen peroxide solution.

The functional layer surface formed by the silver nitrate solution sprayed by the device 5 under the assistance of ammonia water and hydrogen peroxide solution is reduced to form nano silver particles with the particle size of 50 nm-5 mu m. The ultraviolet lamp 6 releases ultraviolet rays to accelerate the reduction of the silver nitrate solution. The hot press compounding process was the same as in example 1.

Example 3

The spraying solution in the example 2 is a mixed solution of 0.1mol/L silver nitrate, polyvinylpyrrolidone with equal mass and dimethylformamide, and other steps are the same as the example 2.

Example 4 (application)

The prepared efficient antibacterial filtering membrane can be widely applied to various scenes. The high-efficiency antibacterial filtering membranes are cut and overlapped, and are filled into a container only with a water inlet and a water outlet, so that a simple filter can be formed, as shown in fig. 4. The multiple filtration membranes are overlapped to slow down the filtration speed, but the filtration effect can be greatly improved, the movement time of water in the filter is long, the contact time of the microorganisms in the water and silver ions released by the nano silver particles in the membranes is longer, impurities in the water can be better filtered, and the sterilization effect can be realized.

As shown in FIG. 5, a single high-efficiency bacteriostatic filter membrane can filter and sterilize water in the nature in the wild to obtain directly drinkable water. The quantitative ratio of the single high-efficiency bacteriostatic filter membrane is only 45 +/-3 g/m²And is convenient for carrying and using in the field. If the quality of the produced water needs to be improved, a large filtering membrane can be folded for use, the thickness of the filtering membrane is increased, and the sterilization and bacteriostasis effects of the filtering membrane are better exerted.

Claims

1. A filtering membrane based on a silver ion antibacterial function is characterized by comprising two supporting layers and a middle functional layer; the supporting layer is a non-woven fabric which plays a role in supporting and protecting; the functional layer is a fiber film with nano silver particles attached to fibers;

the filtering membrane containing a single functional layer and based on the silver ion antibacterial function has the quantitative content of 45 +/-3 g/m²(ii) a The flow rate is more than 25L/m²The thickness of the filter membrane is 200-300 mu m;

the functional layer fiber membrane comprises a fiber membrane made of one of polyacrylonitrile, polypropylene, polyhydroxy polymer, polyamide, polyvinylidene fluoride and hydrophilic modified materials thereof; the fiber diameter of the fiber membrane is 0.01-1 μm, the pore diameter is 0.11-10 μm, the thickness of a single layer is 10-100 μm, and the porosity is more than 20%;

the diameter of the nano silver particles attached to the fiber membrane is 50 nm-5 mu m.

2. The filtering membrane based on the silver ion bacteriostasis function according to claim 1, characterized in that nano silver particles and titanium dioxide and silicon dioxide particles with the diameter of 50 nm-50 μm are attached on the fiber membrane, so as to further improve the antibacterial performance.

3. The silver ion antibacterial function-based filtering membrane according to claim 1, wherein the aperture of the supporting layer is larger than that of the functional layer, the aperture range is 1-50 μm, the porosity is larger than 20%, the apparent contact angle is 80-160 degrees, and the single-layer thickness is smaller than 200 μm.