CN105251376A - Preparing method for nanoparticle/fiber composite membrane - Google Patents

Abstract

The invention relates to preparation of a fiber composite membrane loading nanoparticles. According to the preparing method, the nanoparticles dispersed in a binding agent are sprayed on a fiber material substrate through an electrostatic spraying method, and the nanoparticles are firmly anchored to the fiber surfaces by means of the binding agent to prepare the fiber composite membrane loading the nanoparticles. By means of the method, the nanoparticles are anchored to the fiber surfaces, the high specific surface area and unique structure advantages of the nanoparticles are brought into full play, aggregation of the nanoparticles is restrained, and the problems that in the process of combining the nanoparticles with a fiber material, the nanoparticles are prone to falling, aggregation, uneven dispersion and the like are solved. The nanoparticle/fiber composite membrane prepared through the method can have good application prospects in the fields of air filtration, liquid filtration, pollutant absorption and the like.

Description

A kind of preparation method of nanoparticle/fiber composite film

technical field

The invention belongs to the field of membrane material preparation, in particular to a method for preparing a nanoparticle/fiber composite membrane.

Background technique

Fiber materials are widely used in air filtration, liquid filtration, battery separator, energy storage and other fields due to their advantages of large specific surface area and high porosity. In recent years, the preparation of high-performance composite membrane materials by combining nano-particles with high specific surface area, high mechanical strength, and easy modification with fiber materials is a hot spot in current research. The most common methods for compounding nanoparticles with fibrous materials include hybrid spinning, impregnation, and surface coating. In the process of preparing composite membranes by blending method, the dispersibility of nanoparticles in polymer spinning solution should be considered, and most of nanoparticles are embedded in fiber matrix, so it is difficult to take advantage of the high specific surface area and unique performance advantages of nanoparticles. In the process of preparing composite membranes by surface coating and impregnation methods, the surface bonding force between nanoparticles and fiber materials is poor, which makes nanoparticles easy to agglomerate and fall off.

With the development of electrospinning technology, electrostatic spraying method has been gradually applied to the field of preparation of nanoparticle/fiber composite membranes. Electrostatic spraying is to apply an electric field to a low-polymer solution, so that the solution produces highly charged mist droplets under the action of the electric field. During the spraying process, the solvent evaporates, and the droplet volume gradually decreases, resulting in completely desolvated particles. The electrostatic spraying method is simple and easy to implement, but the nanoparticles and fibers are combined by electrostatic adsorption, which is easy to fall off from the fiber surface, which affects the improvement of the comprehensive performance of the nanoparticle/fiber composite membrane.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention uses the fiber material as the base, sprays the nanoparticles dispersed in the binder on the surface of the fiber material by an electrostatic spraying method, and prepares the fiber composite membrane loaded with the nanoparticles. The preparation process relies on the bonding effect of the binder to firmly load the nanoparticles on the fiber surface, give full play to the high specific surface area and unique structural advantages of the nanoparticles, and effectively inhibit the agglomeration of the nanoparticles on the fiber surface. The nanoparticle/fiber composite film prepared by the present invention comprises the following contents:

1. A fiber composite membrane prepared by electrostatic spraying method, characterized in that: described composite membrane is to take fiber material as the base support layer, and nanoparticles are evenly dispersed in the binder to prepare spraying liquid, and by electrostatic spraying method And the bonding effect of the adhesive sprays and anchors the nanoparticles on the fiber surface.

2. The fiber base material is a non-woven material or fabric produced by melt blown, electrospinning or other processes.

3. The electrostatic spraying method includes the following steps: disperse the nanoparticles in a solvent, ultrasonically treat them for a period of time, mix them uniformly with the binder, and then ultrasonically treat them to prepare a spraying liquid; use an electrospinning device and process for electrostatic spraying , spraying the spray liquid of dispersed nanoparticles onto the surface of the fiber membrane.

4. The nanoparticles are carbon nanotubes, graphene, silica nanoparticles, titanium dioxide nanoparticles, metal nanoparticles, etc.; the solvent is water, acetone, ethanol, chloroform, dimethylformamide , dimethylacetamide, dichloromethane, etc.; the concentration of nanoparticles in the electrostatic spraying liquid is 0.1-10wt%.

5. The adhesive is a water-soluble or solvent-based adhesive, such as water-based polyurethane, polyvinyl alcohol, acrylate, etc., which can be dissolved in water or the above solvents; the quality of the adhesive The fraction is 0.1-5 wt%.

Beneficial effect

In the present invention, the nanoparticles dispersed in the binder are sprayed on the fiber material support layer by the electrostatic spraying method, and the nanoparticles are firmly anchored on the surface of the fiber by means of the bonding effect of the binder, which fully exerts the super high performance of the nanoparticles. The advantages of specific surface area and unique structure advantages can precisely control the loading and uniformity of nanoparticles on the surface of the fiber, inhibit the agglomeration of nanoparticles, and solve the problem of easy falling off, agglomeration, and dispersion of nanoparticles and fiber materials during the composite process. Uneven and other problems.

detailed description

Example 1

Disperse 0.5g of oxidized carbon nanotubes in 50ml of water and sonicate for 30min, then mix it with 50ml of water-based polyurethane, and sonicate for 30min to make a uniformly dispersed carbon nanotube/polyurethane spraying liquid. Put the melt-blown polypropylene nonwoven material on the receiving roller, with a layer of aluminum foil under it, transfer the prepared spray liquid into the syringe, connect it to the syringe pump, set the extrusion speed to 10ml/h, and the syringe The metal needle is connected to the positive pole of the high-voltage power supply, the set voltage is 25kv, the distance between the needle and the receiving roller is set to 10cm, the power is turned on, the electrostatic spraying device starts spraying, the power is turned off after 30 minutes of spraying, and the prepared film is placed at a temperature of Dry in an oven at 60° C. for 3 hours to obtain a carbon nanotube/polypropylene fiber composite film.

Compared with the carbon nanotube/polypropylene fiber composite film prepared in Example 1, the carbon nanotube loading and dispersion uniformity on the fiber surface were significantly improved. The membrane prepared in Example 1 can be used for air filtration, and the filtration efficiency of the membrane for 0.5 μm sodium chloride aerosol can reach 85.7%.

Example 2

Dissolve 2g of polyvinyl alcohol powder in 48ml of water and stir mechanically for 12h, then disperse 0.05g of titanium dioxide in 50ml of water and sonicate for 60min. Mix polyvinyl alcohol and titanium dioxide solution evenly, and ultrasonicate for 30 minutes to prepare uniformly dispersed titanium dioxide/polyvinyl alcohol electrostatic spraying liquid. Add 10 g of polyacrylonitrile into 90 ml of dimethylformamide, and stir magnetically for 8 hours to prepare a polymer spinning solution. Add the spinning solution to the electrospinning device, transfer the prepared electrostatic spraying solution to the syringe, connect the syringe pump, connect the metal needle of the syringe to the positive pole of the high voltage power supply, and turn on the power of the electrospinning and electrostatic spraying device at the same time , synchronous electrospinning and electrostatic spraying of titanium dioxide for 30 minutes, set the extrusion speed of the spinning solution to 20ml/h, the voltage of 25kv, the extrusion speed of the electrostatic spraying solution to 15ml/h, the voltage of 20kv, and the distance setting between the needle head and the receiving roller. Finally, put the polyacrylonitrile fiber composite film assembled with titanium dioxide in an oven at 50°C for 24 hours.

Compared with the titanium dioxide/polyacrylonitrile fiber membrane without binder, the composite membrane prepared in Example 2 has significantly higher loading capacity of titanium dioxide on the fiber surface, and the distribution of titanium dioxide on the fiber surface is relatively uniform. Under the constant pressure of 0.02MPa, the pure water flux of the composite membrane is 2400L/m ² h, and the filtration efficiency of indigo dye waste liquid can reach 89%.

Example 3

Dissolve 1g of polyacrylate powder in 50ml of acetone, stir mechanically for 12h, then disperse 0.1g of graphene in 50ml of acetone and sonicate for 90min, mix polyacrylate and graphene solution evenly, and sonicate for 60min to make evenly dispersed graphite Acrylic/polyacrylate spray fluid. Place the needle-punched polyester non-woven material on the receiving roller with a layer of aluminum foil paper underneath, transfer the prepared electrostatic spraying liquid into the syringe, connect the syringe pump, and connect the metal needle of the syringe to the positive pole of the high-voltage power supply , set the extrusion speed to 25ml/h, the voltage to 15kv, the distance between the needle and the receiving roller to 15cm, turn on the power, the electrostatic spraying device starts to spray, turn off the power after 1 hour of spraying, and place the assembled graphene/polyester fiber composite film in the oven Dry at 60°C for 6h.

Compared with the graphene/polyester fiber composite film without binder, the composite film prepared in Example 3 has significantly improved graphene loading and dispersion uniformity on the polyester fiber surface. The filtration efficiency of the membrane for 1 μm potassium chloride aerosol can reach 80.9%.

Claims (5)

1. A nanoparticle/fiber composite membrane prepared by electrostatic spraying method is characterized in that: the composite membrane is based on a fiber material as a base support layer, and the nanoparticles are evenly dispersed in the binder to prepare a spraying liquid, by means of The electrostatic spraying method and the binding effect of the adhesive spray and anchor the nanoparticles on the surface of the fiber. 2. The nanoparticle/fiber composite film according to claim 1, characterized in that: the fiber base material is a non-woven material or fabric produced by melt blown, electrospinning or other processes. 3. The nanoparticle/fiber composite membrane according to claim 1, characterized in that: the electrostatic spraying method comprises the following steps: 1) Dispersing the nanoparticles in a solvent, ultrasonic treatment for a period of time, uniform mixing with the binder, ultrasonic treatment, and preparation of a spray solution; 2) Electrospinning device and process are used for electrostatic spraying, and the spraying solution of dispersed nanoparticles is sprayed on the surface of the fiber membrane. 4. The nanoparticle/fiber composite film according to claim 3, characterized in that: the nanoparticle is carbon nanotube, graphene, silicon dioxide nanoparticle, titanium dioxide nanoparticle, metal nanoparticle etc.; The solvent used is water, acetone, ethanol, chloroform, dimethylformamide, dimethylacetamide, dichloromethane, etc.; the concentration of nanoparticles in the electrostatic spraying liquid is 0.1-10wt%. 5. The nanoparticle/fiber composite film according to claim 3, characterized in that: the adhesive is a water-soluble or solvent-based adhesive, such as water-based polyurethane, polyvinyl alcohol, acrylate, etc. Or the binder dissolved in the above solvent; the mass fraction of the binder is 0.1-5wt%.