How to Select Equipment and Graphene Oxide Powder?

Overview: Graphene powder is widely used in various fields due to its excellent properties and multiple functions. Adding graphene to polymer matrices can enhance composite materials. For example, adding graphene to bulletproof materials increases tensile strength by 25%, constant tensile strength by 80%, reduces weight by 10%-20%, and improves impact resistance by 30%, significantly enhancing bulletproof effectiveness.

Graphene powder is a substance composed of carbon atoms in an sp² hybridization forming a hexagonal two-dimensional carbon nanomaterial with a honeycomb lattice.

I. Applications of Graphene Powder

Graphene powder is widely used in various fields due to its excellent properties and multiple functions. Adding graphene to polymer matrices as a reinforcement can enhance composite materials. For example, adding graphene to bulletproof materials compared to traditional bulletproof materials increases tensile strength by 25%, constant tensile strength by 80%, reduces weight by 10%-20%, and improves impact resistance by 30%, significantly enhancing bulletproof effectiveness.

However, due to the special structure of graphene powder, it easily agglomerates, affecting its excellent properties. Achieving stable dispersion of graphene in a dispersing medium without destroying its unique physical and chemical properties is a challenge that the industry needs to address.

The important raw material for graphene thermal conductive film is “graphene oxide powder.”

As the name suggests, graphene oxide is the oxidized form of graphene. Introducing active oxygen-containing groups into graphene and then processing it to obtain modified graphene sheets. This increases active reaction sites, making graphene oxide easier to surface modify, enriching functionalization methods, and improving compatibility with polymers, which can effectively enhance the relationship between modified graphene oxide and solvents. It has broader applications in organic and inorganic composite materials. Besides thermal conductivity and heat dissipation applications, it can also be used in lithium batteries, capacitor electrode materials, special coatings, and catalysts in the energy and chemical fields.

II. Overview of Preparation Methods

Currently, the mainstream method for preparing graphene oxide both domestically and internationally is the Hummers method, which can be summarized as follows:

1. Add graphite to a strong acid (concentrated sulfuric acid) and a strong oxidizer to react and obtain graphene oxide.
2. Use magnetic stirring or ultrasonic vibration to exfoliate the obtained graphene oxide.
3. Chemically or thermally reduce graphene oxide to obtain reduced graphene oxide.

Screening is an important process in preparing graphene oxide powder. This material has a very high fineness. During the production process with ordinary screening equipment, issues such as mesh blockage and dust emission can occur. For such materials, it is recommended to use an ultrasonic vibrating screen for production.

Ultrasonic vibrating screens can effectively improve the flat drop (slight contact between powder and mesh opening) and sliding effects in gravity settling of some powders, improve the retention or wedging of high-density metals at the mesh opening, and improve the adhesion effect of electrostatic powders, thereby enhancing screening efficiency and quality. In terms of screening pass rate, it is generally 50%-100% higher than the pass rate without using ultrasonic vibrating screens, and sometimes even up to 400% higher.

III. Structure of Ultrasonic Vibrating Screen:

• High-frequency connection line: Connects the ultrasonic oscillator and ultrasonic resonance power supply via cables.
• Connector: Aviation connection plug.
• Oscillator: High-performance ultrasonic transducer.
• Ultrasonic grid: Consists of an outer grid and a resonance ring.
• Screen mesh: Suitable for 10 mesh to 800 mesh.

This comprehensive guide covers the selection and preparation of graphene oxide powder, emphasizing the importance of using appropriate equipment such as ultrasonic vibrating screens to achieve high-quality and efficient screening.