阅读说明：本技术 石墨烯-聚丙烯腈基纳米复合材料及其制备方法和应用 (Graphene-polyacrylonitrile-based nano composite material and preparation method and application thereof ) 是由 张海龙 权玲 刘焕强 仝玉萍 程龄贺 杨中正 于 2020-04-01 设计创作，主要内容包括：本发明涉及复合材料技术领域,具体来说是石墨烯-聚丙烯腈基纳米复合材料及其制备方法和应用,石墨烯-聚丙烯腈基纳米复合材料按照以下方法制成：将石墨烯和丙烯腈单体在引发剂的作用下制备得到了石墨烯-聚丙烯腈纳米复合材料,然后采用偶联法在石墨烯-聚丙烯腈纳米复合材料上通过交联剂负载了光催化纳米粒子,再经过静电纺丝法纺丝后,制备得到了石墨烯-聚丙烯腈基纳米复合材料。本发明不仅制备得到了具有光催化性能的石墨烯-聚丙烯腈基纳米复合材料,而且能够通过石墨烯和光催化剂的协同效应来分解水体中的有毒有机物,增加水体溶解氧含量,从而实现了污水的净化及处理。(The invention relates to the technical field of composite materials, in particular to a graphene-polyacrylonitrile-based nano composite material and a preparation method and application thereof, wherein the graphene-polyacrylonitrile-based nano composite material is prepared according to the following method: preparing graphene-polyacrylonitrile nano composite material by graphene and acrylonitrile monomer under the action of an initiator, then loading photocatalytic nano particles on the graphene-polyacrylonitrile nano composite material by a coupling method through a cross-linking agent, and spinning by an electrostatic spinning method to obtain the graphene-polyacrylonitrile nano composite material. The method not only prepares the graphene-polyacrylonitrile-based nano composite material with photocatalytic performance, but also can decompose toxic organic matters in the water body through the synergistic effect of the graphene and the photocatalyst, and increase the dissolved oxygen content of the water body, thereby realizing the purification and treatment of sewage.)

1. The graphene-polyacrylonitrile-based nano composite material is characterized by being prepared by the following steps: graphene and acrylonitrile monomers are prepared under the action of an initiator to obtain a graphene-polyacrylonitrile nano composite material, then photocatalytic nano particles are loaded on the graphene-polyacrylonitrile nano composite material through a cross-linking agent by adopting a coupling method, and the graphene-polyacrylonitrile nano composite material with photocatalytic performance is prepared after spinning by an electrostatic spinning method.

2. The graphene-polyacrylonitrile-based nanocomposite as claimed in claim 1, wherein the initiator is a water-soluble initiator or a solvent-based initiator, the water-soluble initiator is ammonium persulfate or ascorbic acid, and the solvent-based initiator is azobisisobutyronitrile.

3. The graphene-polyacrylonitrile-based nanocomposite according to claim 1, wherein the cross-linking agent is an aqueous solution of methyltrimethoxysilane or silica sol, and if the cross-linking agent is an aqueous solution of methyltrimethoxysilane, the mass ratio of methyltrimethoxysilane to water is 1-2: 5.

4. the graphene-polyacrylonitrile-based nanocomposite material of claim 1, wherein the photocatalytic nanoparticles are TiO₂、SnO₂、ZrO₂、CrSe、WO₃、Fe₂O₃One kind of (1).

5. The method for preparing the graphene-polyacrylonitrile-based nanocomposite material according to claim 1, comprising the following steps:

(1) preparing a graphene-polyacrylonitrile nano composite material: adding graphene and acrylonitrile monomers into a solvent together, adding an initiator, reacting at 50-70 ℃ in a nitrogen atmosphere, cooling to room temperature, filtering, washing and drying to obtain a graphene-polyacrylonitrile nano composite material;

wherein the mass ratio of the graphene to the acrylonitrile monomer is 1:100-1000, and the mass ratio of the initiator to the acrylonitrile monomer is 3-5: 1000, parts by weight;

(2) preparing a graphene-polyacrylonitrile-based nano composite material: adding a cross-linking agent into N, N' -dimethylformamide, stirring and refluxing for 1-3h at 105-115 ℃, adding photocatalytic nanoparticles and the graphene-polyacrylonitrile nano composite material prepared in the step (1), continuously refluxing for 3-6h, spinning by an electrostatic spinning method, washing with water and drying to prepare the graphene-polyacrylonitrile nano composite material;

wherein the photocatalytic nano particles account for 8-12 wt% of the total amount of the photocatalytic nano particles and the graphene-polyacrylonitrile nano composite material, and the cross-linking agent accounts for 5-10 wt% of the total amount of the photocatalytic nano particles and the graphene-polyacrylonitrile nano composite material.

6. The preparation method of the graphene-polyacrylonitrile-based nanocomposite material according to claim 5, wherein if the initiator in the step (1) is a water-soluble initiator, the solvent is water, and the reaction is carried out at 50-70 ℃ for 2-4 h; if the initiator in the step (1) is a solvent type initiator and the solvent is N, N' -dimethylformamide or dimethyl sulfoxide, reacting for 24-48h at 50-70 ℃.

7. The method for preparing the graphene-polyacrylonitrile-based nanocomposite material according to claim 5, wherein the electrospinning method of the step (2) has the following spinning conditions: spinning voltage is 15-20KV, injection speed is 0.6-1.2mm/h, and then the nano-fiber is drafted at the hot drafting temperature of 95-100 ℃.

8. The graphene-polyacrylonitrile based nanocomposite material according to claim 1, for use in sewage purification and treatment.

Technical Field

The invention relates to the technical field of composite materials, in particular to a graphene-polyacrylonitrile-based nano composite material as well as a preparation method and application thereof.

Background

Since the 20 th century, people enjoyed comfort and convenience brought by rapidly developing technologies and also had a bitter taste of continuous deterioration of living environment caused by blindness and short sight, and environmental pollution became serious day by day. In order to meet the requirement of sustainable development, pollution control and treatment become a problem to be solved urgently; among various environmental pollutions, the most common, most important and most influential is water pollution, so effective control and treatment of sewage are the key points of comprehensive environmental treatment, and currently, typical treatment methods used for sewage mainly include: physical methods, chemical methods and microbial treatment methods, which play a great role in the treatment of sewage, but in most cases, the sewage needs to be treated in a centralized manner by a treatment tank, so that the sewage needs to be introduced into the treatment tank and then treated in a centralized manner, and in the prior art, not all the sewage can be introduced into the treatment tank, such as sewage in a lake, so that a method for treating the sewage which cannot be treated in a centralized manner is needed; the photocatalytic oxidation technology is a novel technology with wide application prospect, and is particularly suitable for treating sewage which cannot be treated in a centralized way through a treatment tank.

At present, the application of graphene photocatalysis technology to sewage treatment is a hotspot of research, and the sewage treatment principle is to recover self-purification of water by using visible light, natural light is the only light source, no power device is needed, and no chemical reagent or biological strain is needed to be added. Graphene (Graphene) is a novel inorganic material, is made of cheap graphite, has the ultimate modulus of 1.01TPa and the ultimate strength of 116GPa, is light in weight, has a large specific surface area and has excellent electron transport properties.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide the graphene-polyacrylonitrile-based nano composite material and the preparation method and application thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

the graphene-polyacrylonitrile-based nanocomposite is prepared by the following steps: graphene and acrylonitrile monomers are prepared under the action of an initiator to obtain a graphene-polyacrylonitrile nano composite material, then photocatalytic nano particles are loaded on the graphene-polyacrylonitrile nano composite material through a cross-linking agent by adopting a coupling method, and the graphene-polyacrylonitrile nano composite material with photocatalytic performance is prepared after spinning by an electrostatic spinning method.

Preferably, the initiator is a water-soluble initiator or a solvent-type initiator, the water-soluble initiator is ammonium persulfate or ascorbic acid, and the solvent-type initiator is azobisisobutyronitrile.

Preferably, the cross-linking agent is an aqueous solution of methyltrimethoxysilane or silica sol, and if the cross-linking agent is the aqueous solution of methyltrimethoxysilane, the mass ratio of methyltrimethoxysilane to water is 1-2: 5.

preferably, the photocatalytic nanoparticle is TiO₂、SnO₂、ZrO₂、CrSe、WO₃、Fe₂O₃One kind of (1).

The invention also provides a preparation method of the graphene-polyacrylonitrile-based nano composite material, which comprises the following steps:

(1) preparing a graphene-polyacrylonitrile nano composite material: adding graphene and acrylonitrile monomers into a solvent together, adding an initiator, reacting at 50-70 ℃ in a nitrogen atmosphere, cooling to room temperature, filtering, washing and drying to obtain a graphene-polyacrylonitrile nano composite material;

wherein the mass ratio of the graphene to the acrylonitrile monomer is 1:100-1000, and the mass ratio of the initiator to the acrylonitrile monomer is 3-5: 1000, parts by weight;

(2) preparing a graphene-polyacrylonitrile-based nano composite material: adding a cross-linking agent into N, N' -dimethylformamide, stirring and refluxing for 1-3h at 105-115 ℃, adding photocatalytic nanoparticles and the graphene-polyacrylonitrile nano composite material prepared in the step (1), continuously refluxing for 3-6h, spinning by an electrostatic spinning method, washing with water and drying to prepare the graphene-polyacrylonitrile nano composite material;

wherein the photocatalytic nano particles account for 8-12 wt% of the total amount of the photocatalytic nano particles and the graphene-polyacrylonitrile nano composite material, and the cross-linking agent accounts for 5-10 wt% of the total amount of the photocatalytic nano particles and the graphene-polyacrylonitrile nano composite material.

Preferably, if the initiator in the step (1) is a water-soluble initiator, the solvent is water, and the reaction is carried out for 2 to 4 hours at the temperature of between 50 and 70 ℃; if the initiator in the step (1) is a solvent type initiator and the solvent is N, N' -dimethylformamide or dimethyl sulfoxide, reacting for 24-48h at 50-70 ℃.

Preferably, the spinning conditions of the electrospinning method in the step (2) are as follows: spinning voltage is 15-20KV, injection speed is 0.6-1.2mm/h, and then the nano-fiber is drafted at the hot drafting temperature of 95-100 ℃.

The invention also protects the application of the graphene-polyacrylonitrile-based nano composite material in sewage purification and treatment.

Compared with the prior art, the invention has the beneficial effects that:

1. the method comprises the step of preparing the graphene-polyacrylonitrile nano composite material from the graphene and the acrylonitrile under the action of the initiator, wherein the molecular weight of the graphene-polyacrylonitrile nano composite material is 12 × 10⁴-30×10⁴The molecular weight is distributed between 1.5 and 3.0, then photocatalytic nanoparticles are loaded on the graphene-polyacrylonitrile nano composite material by a coupling method, the graphene in the graphene-polyacrylonitrile nano composite material has the adsorption characteristics of large specific surface area, high adsorption speed and large capacity, gaps capable of being filled with the photocatalytic nanoparticles are formed among the polyacrylonitriles, and when the graphene-polyacrylonitrile nano composite material is mixed with the photocatalytic nanoparticles, the photocatalytic nanoparticles are adsorbed on the graphene-polyacrylonitrile nano composite material, the invention also adds the cross-linking agent which enables the photocatalytic nanoparticles to be bonded on the graphene-polyacrylonitrile nano composite material and keep stable, so that the photocatalytic particles are prevented from falling off from the graphene-polyacrylonitrile nano composite material after spinning is finished, thereby submerging and reducing the photocatalytic performance of the photocatalytic particles.

2. The graphene material has excellent performance, but the graphene material has large specific surface area and is easy to agglomerate, which is unfavorable for the application prospect of the graphene, so that the graphene and acrylonitrile are polymerized, the agglomeration of the graphene is effectively avoided, the uniform distribution of the graphene is realized, the polyacrylonitrile has excellent performances of weather resistance, sunlight resistance and chemical reagent corrosion resistance, and particularly has extremely strong stability in inorganic acid, bleaching powder, hydrogen peroxide and general organic reagents, so that the polyacrylonitrile realizes the structural integrity of the graphene-polyacrylonitrile nano composite material when sewage is treated, an effective loading matrix is provided for the photocatalytic nano particles, the photocatalytic nano particles can be effectively treated for a long time, and the composite material is spun and can be woven into a net structure when in use, harmful substances and algae can be netted, the self-cleaning function of the water body is improved, and meanwhile, the recovery of the photocatalytic nano particles is facilitated.

3. The graphene is selected because the arrangement mode of the carbon atoms of the internal graphene is the same as that of the graphite monoatomic layer and sp²The hybrid orbit is bonded, so the hybrid orbit has the characteristics of high strength and good toughness; in addition, graphene is a two-dimensional crystal in terms of physical properties, the movement speed of electrons reaches 1/300 of the speed of light, which is far higher than the movement speed of electrons in a common conductor, so that graphene is called as "charge carriers", and the basic principle of heterogeneous photocatalysis on the surface of photocatalytic nanoparticles is as follows: when the surface of the photocatalytic nanoparticle is irradiated by light with energy higher than the forbidden bandwidth, electrons on a valence band are excited and jump to a conducting band, and meanwhile, corresponding holes are generated in the valence band, at the moment, electron-hole pairs are generated inside the photocatalytic nanoparticle, the electron-hole pairs migrate to different positions on the surface of the nanoparticle and perform corresponding oxidation or reduction reaction with reactants adsorbed on the surface of a semiconductor, and meanwhile, excited-state titanium dioxide returns to the ground state again.

Detailed Description

The following description will be made in detail with reference to preferred embodiments of the present invention in conjunction with embodiments 1 to 3.