阅读说明：本技术 一种静电纺纳米空气过滤材料的制备方法 (Preparation method of electrostatic spinning nano air filtering material ) 是由 孙浚豪 于 2020-05-09 设计创作，主要内容包括：本发明公开了一种静电纺纳米空气过滤材料的制备方法,包括以下步骤：步骤1,基布纺制；以碳纤维纱线为经纬纱,通过平纹组织结构,编织基布；步骤2,支架隔层制备；步骤3,纳米蛛网纤维层制备；步骤4,层叠支架隔层制备；步骤5,表层纳米蛛网纤维层制备。本发明能够适用于工业化空气过滤材料的生产过程,制作工艺合理,制备的空气过滤材料性能稳定,具有良好的过滤效率,力学强度好,滤阻小,容尘量大,使用寿命长。(The invention discloses a preparation method of an electrostatic spinning nano air filtering material, which comprises the following steps: step 1, spinning base cloth; weaving base cloth by using carbon fiber yarns as warp and weft yarns through a plain weave structure; step 2, preparing a bracket interlayer; step 3, preparing a nano cobweb fiber layer; step 4, preparing a laminated bracket interlayer; and 5, preparing the surface nano spider web fiber layer. The invention can be suitable for the production process of industrialized air filtering materials, the manufacturing process is reasonable, and the prepared air filtering material has stable performance, good filtering efficiency, good mechanical strength, small filtration resistance, large dust holding capacity and long service life.)

1. The preparation method of the electrostatic spinning nano air filter material is characterized by comprising the following steps of:

step 1, spinning base cloth; weaving base cloth by using carbon fiber yarns as warp and weft yarns through a plain weave structure;

step 2, preparing a bracket interlayer; installing spinning nozzles at two poles of an electrospinning device, and flatly laying a base fabric on a receiving roller; respectively installing the PS spinning solution and the PVDF spinning solution on the anode and the cathode of electrospinning; enabling PS spinning solution sprayed out of the anode and PVDF spinning solution sprayed out of the cathode to converge into a strand through a spinning nozzle and then reach the base cloth, and forming a first layer of support interlayer on the base cloth;

step 3, preparing a nano cobweb fiber layer; placing the base cloth with the surface compounded with the bracket interlayer on a receiving roller, installing PMIA spinning solution in a positive spinneret of an electrospinning device, taking the receiving roller as a negative electrode receiving end, and electrospinning a compound nano-cobweb fiber layer on the surface of the base cloth compounded with the bracket interlayer through PMIA;

step 4, preparing a laminated bracket interlayer; installing spinning nozzles at two poles of an electrospinning device, and flatly laying the base cloth compounded with the nano-cobweb fiber layer on a receiving roller; respectively installing the PS spinning solution and the PVDF spinning solution on the anode and the cathode of electrospinning; combining PS spinning solution sprayed from the anode and PVDF spinning solution sprayed from the cathode into a jet flow through a spinning nozzle, and then enabling the jet flow to reach the base cloth, and continuously compounding the support interlayer on the base cloth compounded with the nano cobweb fiber layer;

step 5, preparing a surface nano spider web fiber layer; and (4) after 1 or more times of processes of the step (3) and the step (4), finally compounding the surface layer nano-cobweb fiber layer on the base cloth through electrospinning.

2. The method for preparing an electrostatic spinning nano air filter material as claimed in claim 1, wherein in the step 1, the thickness of the base cloth is 0.05-0.25 mm.

3. The method for preparing an electrostatic spinning nano air filter material according to claim 1, wherein in the step 2 and the step 4, the concentration of the PS spinning solution is 18-25wt%, and the concentration of the PVDF spinning solution is 17-20 wt%; the voltage of electrostatic spinning is 20kv, the distance from the jet junction to the base fabric is 7-12cm, and the distance from the spinneret of the PS spinning solution and the spinneret of the PVDF spinning solution to the jet junction is 4-6 cm.

4. The method for preparing electrostatic spinning nano air filter material according to claim 3, wherein in the step 2 and the step 4, the spinning environment is as follows: the temperature is controlled at 25 +/-2 ℃, and the relative humidity is controlled at 30%.

5. The method for preparing an electrostatic spinning nano air filter material according to claim 4, wherein in the step 3 and the step 5, PMIA fibers are dissolved in a DMAc solution, and the PMIA spinning solution is obtained by magnetic stirring under the heating condition of 80 ℃, and the concentration of the PMIA spinning solution is 8-12 wt%; the voltage of electrostatic spinning is 30kv, and the distance between the spinning nozzle and the base fabric is 20-25 cm.

6. The method for preparing electrostatic spinning nano air filter material according to claim 5, wherein in the step 3 and the step 5, the spinning environment is as follows: the temperature is controlled at 25 +/-2 ℃, and the relative humidity is controlled at 40%.

7. The preparation method of the electrostatic spinning nano air filter material according to claim 5, wherein the base cloth is dried in a vacuum oven at 70 ℃ for 6-8 hours after being compounded with each layer of the bracket interlayer or the nano spider web fiber layer.

8. The method for preparing electrostatic spinning nano air filter material according to claim 5, wherein the composite nano spider web fiber layer has no more than 5 layers.

9. The method for preparing an electrostatic spinning nano air filter material according to claim 5, wherein the thickness of each nano spider web fiber layer is 6-10 μm; the thickness of each layer of the bracket interlayer is 18-25 μm.

Technical Field

The invention relates to the field of electrostatic spinning, in particular to a preparation method of an electrostatic spinning nano air filtering material.

Background

The air filtering material can effectively intercept harmful dust particles in the air so as to meet the requirements of clean spaces of people's life and industrial production. At present, materials applied to air filtration facilities and equipment mainly include ultrafine glass fibers, carbon fiber felt mats, polymer fabrics, melt-blown non-woven products, and the like. The melt-blown non-woven fabrics, especially electret treated non-woven fabrics, occupy the mainstream market of the similar products with higher filtration efficiency and relatively lower pressure drop, but the products have certain limitations in the application process. Firstly, the filtration efficiency of the electret product on ionic particles is obviously improved, but the filtration efficiency on oily particles is hardly improved obviously; secondly, the electret products have poor resistance to cleaning and solvents.

Compared with the air filtering material, the nanofiber prepared based on the electrostatic spinning method has the advantages of large specific surface area, high porosity, simple preparation process and the like, and can efficiently filter out tiny particles in air by means of mechanical interception. In recent years, with the continuous and deep research, researchers find that the air filtration performance of the material can be remarkably improved by further refining the fiber diameter, and at present, various different types of electrostatic spinning fiber air filtration materials are successfully prepared, but the fiber diameter is more than 100nm, the further refining is difficult, the great improvement of the filtration performance of the material is seriously limited, and the bottleneck problem of insufficient filtration efficiency of particles with the most penetrable particle diameter (0.3 mu m) still exists.

Disclosure of Invention

In order to solve the technical problems, the invention provides a preparation method of an electrostatic spinning nano air filtering material, which solves the problems that the diameter of nano fibers prepared by the existing electrostatic spinning method is difficult to further refine, the filtration performance of the material is seriously limited to be greatly improved, and simultaneously the mechanical strength is poor, the filtration resistance is high and the dust holding capacity is small by improving the preparation process and adopting a three-dimensional filtering structure loaded layer by layer.

In order to achieve the purpose, the technical scheme of the invention is as follows: a preparation method of an electrostatic spinning nanometer air filtering material comprises the following steps:

step 1, spinning base cloth; weaving base cloth by using carbon fiber yarns as warp and weft yarns through a plain weave structure;

step 2, preparing a bracket interlayer; installing spinning nozzles at two poles of an electrospinning device, and flatly laying a base fabric on a receiving roller; respectively installing the PS spinning solution and the PVDF spinning solution on the anode and the cathode of electrospinning; enabling PS spinning solution sprayed out of the anode and PVDF spinning solution sprayed out of the cathode to converge into a strand through a spinning nozzle and then reach the base cloth, and forming a first layer of support interlayer on the base cloth;

step 3, preparing a nano cobweb fiber layer; placing the base cloth with the surface compounded with the bracket interlayer on a receiving roller, installing PMIA spinning solution in a positive spinneret of an electrospinning device, taking the receiving roller as a negative electrode receiving end, and electrospinning a compound nano-cobweb fiber layer on the surface of the base cloth compounded with the bracket interlayer through PMIA;

step 4, preparing a laminated bracket interlayer; installing spinning nozzles at two poles of an electrospinning device, and flatly laying the base cloth compounded with the nano-cobweb fiber layer on a receiving roller; respectively installing the PS spinning solution and the PVDF spinning solution on the anode and the cathode of electrospinning; combining PS spinning solution sprayed from the anode and PVDF spinning solution sprayed from the cathode into a jet flow through a spinning nozzle, and then enabling the jet flow to reach the base cloth, and continuously compounding the support interlayer on the base cloth compounded with the nano cobweb fiber layer;

step 5, preparing a surface nano spider web fiber layer; and (4) after 1 or more times of processes of the step (3) and the step (4), finally compounding the surface layer nano-cobweb fiber layer on the base cloth through electrospinning.

In the step 2 and the step 4, under the action of the electric field force, the PS jet flow sprayed out of the anode and the PVDF jet flow sprayed out of the cathode are converged into one jet flow on the way, and the converged jet flow is slowed down due to partial neutralization of positive and negative charges and finally reaches the base cloth. The fiber carrying positive charges and the fiber carrying negative charges meet and are combined into a whole under the action of coulomb force, partial charges are neutralized, new composite fibers carry residual charges to move to a base cloth at a receiving end, and the two components in the fiber after the composite are stressed differently due to different carried charges before the composite, namely different stretching sizes of the composite fibers under the action of coulomb force and the difference of mechanical properties such as breaking elongation strength of high polymers, so that different flexibilities are generated, and a spiral electrostatic spinning structure is obtained.

In a preferable embodiment of the present invention, in step 1, the thickness of the base fabric is 0.05 to 0.25 mm.

As a preferable scheme of the invention, in the step 2 and the step 4, the concentration of the PS spinning solution is 18-25wt%, and the concentration of the PVDF spinning solution is 17-20 wt%; the voltage of electrostatic spinning is 20kv, the distance from the jet junction to the base fabric is 7-12cm, and the distance from the spinneret of the PS spinning solution and the spinneret of the PVDF spinning solution to the jet junction is 4-6 cm.

As a preferred embodiment of the present invention, in step 2 and step 4, the spinning environment is: the temperature is controlled at 25 +/-2 ℃, and the relative humidity is controlled at 30%.

As a preferable scheme of the invention, in the step 3 and the step 5, PMIA fibers are dissolved in a DMAc solution, and the PMIA spinning solution is obtained by magnetic stirring under the heating condition of 80 ℃, wherein the concentration of the PMIA spinning solution is 8-12 wt%; the voltage of electrostatic spinning is 30kv, and the distance between the spinning nozzle and the base fabric is 20-25 cm.

As a preferred embodiment of the present invention, in step 3 and step 5, the spinning environment is: the temperature is controlled at 25 +/-2 ℃, and the relative humidity is controlled at 40%.

As a preferred scheme of the invention, after each layer of bracket interlayer or nano-cobweb fiber layer is compounded on the base cloth, the base cloth is dried in a vacuum oven at 70 ℃ for 6 to 8 hours. In the drying process, residual solvent and electric charges can be effectively removed.

As a preferred embodiment of the present invention, the composite nano-spider web fiber layer does not exceed 5 layers.

As a preferable mode of the present invention, the thickness of each layer of the nano-spider web fiber layer is 6 to 10 μm; the thickness of each layer of the bracket interlayer is 18-25 μm.

Through the technical scheme, the technical scheme of the invention has the beneficial effects that: the invention can be suitable for the production process of industrialized air filtering materials, the manufacturing process is reasonable, and the prepared air filtering material has stable performance, good filtering efficiency, good mechanical strength, small filtration resistance, large dust holding capacity and long service life. The air filter material mainly comprises base cloth, bracket interlayer and nano spider web fiber layer which are compounded on the surface of the base cloth and are sequentially laminated at intervals. The bracket interlayer formed by micron-sized spiral electrostatic spinning has good structural strength and stability, and a through three-dimensional porous structure is formed inside the bracket interlayer, so that the filter resistance is reduced; the nano-cobweb fiber layer is formed through nano-scale two-dimensional cobweb electrostatic spinning, good filtering efficiency is achieved, a three-dimensional filtering structure is formed in a layer-by-layer assembling mode, and due to the fact that the thickness of a single layer is thin, good filtering efficiency and dust holding capacity are achieved while low filtering resistance is guaranteed.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.