阅读说明：本技术 一种利用静电吸附作用制备石墨烯增铝复合浆料的方法 (Method for preparing graphene aluminum-added composite slurry by utilizing electrostatic adsorption effect ) 是由 赵斌 詹科 刘福海 于 2020-04-24 设计创作，主要内容包括：本发明涉及利用静电吸附作用制备石墨烯增铝复合浆料的方法。本发明的方法包括制备氧化石墨烯,氧化石墨烯制备完成后需要对其进行离心处理,获取尺寸基本一致的氧化石墨烯,将氧化石墨烯和颗粒状铝粉加入到水和酒精的混合溶液中,加入稀HCl溶液,玻璃棒搅拌至上层溶液澄清,随后倒去上清液,制备出石墨烯增铝复合浆料。本发明采用静电自组装的方法,实现氧化石墨烯的均匀分散、以及氧化石墨烯的部分还原,制备出石墨烯增强铝复合浆料。本发明避免使用难以去除的有机表面活性剂,显著的提高了复合浆料的分散性和导电性能。(The invention relates to a method for preparing graphene aluminum-added composite slurry by utilizing electrostatic adsorption. The method comprises the steps of preparing graphene oxide, carrying out centrifugal treatment on the graphene oxide after the preparation of the graphene oxide is finished to obtain the graphene oxide with basically consistent size, adding the graphene oxide and granular aluminum powder into a mixed solution of water and alcohol, adding a dilute HCl solution, stirring by a glass rod until the upper layer solution is clarified, and then pouring out the supernatant to prepare the graphene aluminum-added composite slurry. According to the invention, a static self-assembly method is adopted to realize uniform dispersion of graphene oxide and partial reduction of the graphene oxide, so that the graphene reinforced aluminum composite slurry is prepared. The invention avoids using organic surface active agent which is difficult to remove, and obviously improves the dispersibility and the conductivity of the composite slurry.)

1. A method for preparing graphene aluminum-increasing composite slurry by utilizing electrostatic adsorption is characterized by comprising the steps of preparing graphene oxide, centrifuging the graphene oxide after the preparation of the graphene oxide is completed to obtain the graphene oxide with basically consistent size, adding the graphene oxide and granular aluminum powder into a mixed solution of water and alcohol, adding a diluted HCl solution, stirring by a glass rod until the upper layer solution is clarified, and then pouring out the supernatant to prepare the graphene aluminum-increasing composite slurry.

2. The method for preparing graphene aluminum-added composite slurry by utilizing electrostatic adsorption according to claim 1, wherein high-purity graphite powder is used as a raw material, and graphene oxide is prepared by adopting an improved Hummer's method.

3. The method for preparing graphene aluminum-added composite slurry by utilizing electrostatic adsorption according to claim 1, wherein the volume fraction of water and alcohol in the mixed solution of water and alcohol is between 1:8 and 1: 9.

4. The method for preparing graphene aluminum increasing composite slurry by utilizing electrostatic adsorption according to claim 1, wherein a dilute HCl solution is added in a dropwise manner, and the dilute HCl solution is 0.1mol/L HCl solution.

Technical Field

The invention relates to the field of conductive slurry, in particular to a preparation method of graphene aluminum-added composite slurry.

Background

Graphene has the advantages of low density, good thermal conductivity, low thermal expansion coefficient and the like, and is considered to be a very promising reinforcement from birth. The electronic paste product is an electronic functional material integrating materials, metallurgy, chemical engineering and electronic technologies, and is a basic material of hybrid integrated circuits, sensitive elements, surface assembly technologies, resistance networks, displays, various electronic discrete elements and the like, wherein the Al electrode paste has the advantages of low price and stable electrical property. Al and Si easily form PN junctions, have long-wave response characteristics, have good ohmic contact characteristics with PTC thermistor ceramics, and have good aging resistance, so Al conductor paste is often selected as an electrode material of PTC thermistors and a material of a back surface field of a ground single crystal Si solar cell.

The search of the prior art literature shows that a thesis of 'research progress and development trend of electronic paste' is published in 2008, No. 1 and pages 48-52 by Xuan Tianpeng et al, who is a metal functional material, and the characteristics and problems of the aluminum paste are analyzed, so that the aluminum paste has low impact current resistance and is easy to burn down an electrode under a large impact current. Therefore, improving the conductivity of the aluminum paste is one of the key points for improving the above properties. Chen Wei et al reported that a coupling agent is adopted to modify graphene oxide to improve the conductivity of graphene oxide in the invention patent of a functionalized graphene-based solar back aluminum slurry and a preparation method thereof, and chemical substances added in the method are toxic and difficult to remove. Meanwhile, Jingyue Wang et al published a paper of "relationship with graphene nano sheets in aluminum sheets composites" in script materials 2012, Vol66, 594-597 (materials promulgated, 2012, volume 66, page 594-597), and studied the problem of improving the uniform dispersion of graphene by adding PVA solvent to modify the surface of aluminum powder. But PVA is difficult to handle clean later in the process. Therefore, in the preparation process of the graphene-aluminum composite powder, the increased uniform dispersibility of the graphene becomes one of the key problems in preparing the high-performance graphene-aluminum-based composite powder.

Disclosure of Invention

The invention aims to provide a method for preparing graphene aluminum-added composite slurry by utilizing electrostatic adsorption. The method is non-toxic, and the prepared graphene aluminum-added composite slurry has good dispersibility.

In order to realize the purpose, the invention is realized by the following technical scheme:

a method for preparing graphene aluminum-increasing composite slurry by utilizing electrostatic adsorption comprises the steps of preparing graphene oxide, carrying out centrifugal treatment on the graphene oxide after the graphene oxide is prepared, obtaining graphene oxide with basically consistent size, adding the graphene oxide and granular aluminum powder into a mixed solution of water and alcohol, adding a dilute HCl solution, stirring by a glass rod until an upper layer solution is clarified, and then pouring out a supernatant to prepare the graphene aluminum-increasing composite slurry. Dilute HCl removes oxide layer on the surface of granular aluminum powder and partial hydrolysis occurs to generate Al³⁺And carrying out electrostatic self-assembly adsorption with negatively charged graphene oxide to realize uniform dispersion of the graphene oxide and partial reduction of the graphene oxide, and preparing the graphene aluminum-added composite slurry. The dilute HCl used is non-toxic.

High-purity graphite powder is used as a raw material, and an improved Hummer's method is adopted to prepare graphene oxide.

In the mixed solution of water and alcohol, the volume fraction of the water and the alcohol is 1: 8-1: 9.

Adding a dilute HCl solution in a dropwise manner, wherein the dilute HCl solution is 0.1mol/L HCl solution.

The invention has the beneficial effects that: compared with the traditional aluminum paste, the method for preparing the multipurpose graphene aluminum-added composite paste provided by the invention has the advantages that the graphene with good conductivity is added, the oxidation of the surface of the aluminum paste is effectively reduced, and the conductivity of the aluminum paste is improved, so that the method is very favorable for the application of the aluminum paste in electronic components. By adding a small amount of dilute hydrochloric acid, the graphene oxide and the granular aluminum powder are adsorbed by electrostatic self-assembly, so that the graphene oxide is uniformly dispersed and partially reduced, and the graphene reinforced aluminum composite slurry is prepared.

Drawings

FIG. 1 is a photograph of a comparative sample of graphene oxide and aluminum powder slurry of example 1 before and after treatment.

Fig. 2 is the X-ray diffraction results of the graphene aluminized composite paste of example 1.

Detailed Description

The present invention is described below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the embodiments, and based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some technical features without creative efforts based on the disclosed technical contents, and these substitutions and modifications are within the protection scope of the present invention.

Examples

(1) Preparation of graphene oxide

The preparation method of the graphene oxide comprises the following steps: 1. high-purity graphite 5g and 2.5g of NaNO are adopted₃To a certain amount of H₂SO₄Adding into the solution, stirring, and gradually adding KMnO₄Evenly stirring for about 1 hour; 3. adding 200ml water, stirring at 100 deg.C for 1 hr, 4, adding small amount of H₂O₂And a HCl solution. And then centrifugally separating the graphene oxide with different sizes to obtain a graphene oxide solution with basically consistent size.

(2) Preparation of graphene-aluminum composite slurry

Graphene oxide and granular aluminum powder (about 10g) were added to a mixed solution of water and alcohol (water: alcohol: 1:8 to 1: 9). 2ml of 0.1mol/L diluted HCl solution is added, a glass rod is stirred until the upper layer solution is clear (about 5-10 minutes), and then the supernatant is poured off to obtain the composite slurry. Wherein the ratio of the graphene to the aluminum powder is about 0.3-1.0 wt%. In the process, dilute HCl removes an oxide layer on the surface of the granular aluminum powder, and partial hydrolysis is carried out to generate Al³⁺And performing electrostatic self-assembly adsorption with negatively charged graphene oxide to realize uniform dispersion of the graphene oxide and partial reduction of the graphene oxide, and preparing the graphene aluminum-added composite slurry(see FIG. 1 before and after adsorption).