Magnetic Iron Oxide-Graphene Composite Shielding
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Solution Overview
Problem
Current methods for preparing graphene-based electromagnetic wave absorbers face challenges such as non-uniform magnetic material introduction, high defect rates, and limitations in mass production due to complex processes and the need for toxic substances.
Innovation Solution
A method involving the use of a halogen salt of iron to intercalate graphite, followed by heat treatment, primary amine reaction, washing, high-speed homogenization, and sonication or high-pressure homogenization to form magnetic iron oxide-graphene composites, which allows for uniform magnetic particle coating on graphene without reducing agents and enhances exfoliation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If magnetic material is introduced onto the surface of graphene using conventional methods, then magnetic properties are added to graphene, but the magnetic material distribution becomes non-uniform and defects are caused on the graphene surface
Solution Approach 1:
The patent combines the graphene preparation process and magnetic material introduction process into a single integrated reaction step. Iron salts are introduced during the chemical vapor deposition process, and magnetic iron oxide particles are formed in-situ on the graphene surface during the same heating treatment, eliminating the need for separate magnetic material introduction steps and avoiding the defects associated with conventional two-step methods
Solution Approach 2:
The patent introduces iron salts as intercalants into the graphite structure before the chemical vapor deposition process. This preliminary introduction of iron-containing compounds ensures that magnetic material precursors are already positioned within the graphite layers, enabling uniform distribution of magnetic iron oxide particles on the resulting graphene surface
2Manufacturing precision
If chemical vapor deposition is used to prepare graphene, then high quality graphene is obtained, but mass production is limited due to low production speed
Solution Approach 1:
The patent merges multiple functions into the chemical vapor deposition process: graphene formation, magnetic material incorporation, and surface functionalization all occur in a single step. This integration maintains the high quality of CVD-prepared graphene while improving productivity by eliminating subsequent processing steps required in conventional methods
3Ease of manufacture
If physical exfoliation method is used to prepare graphene, then simple process is achieved, but mass production is not suitable due to very low exfoliation yield
Solution Approach 1:
The patent changes the fundamental approach from physical exfoliation to chemical synthesis via chemical vapor deposition. This parameter change enables controlled formation of graphene with desired properties while achieving much higher production yields suitable for mass production, without sacrificing process simplicity
4Productivity
If graphite is oxidized and reduced to obtain graphene, then graphene can be produced, but toxic substances must be used and defects of graphene are difficult to control
Solution Approach 1:
The patent extracts and eliminates the harmful oxidation and reduction steps from the conventional graphite-to-graphene conversion process. By using direct chemical vapor deposition, the method avoids toxic oxidizing agents and reducing agents while producing high-quality graphene with controlled defects, thereby removing the harmful factors associated with wet chemical methods
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables the production of magnetic iron oxide-graphene composites with improved uniformity and environmental sustainability, suitable for efficient electromagnetic wave shielding with high production efficiency.
Implementation Method 1
mixing graphite and a halogen salt of iron and heat-treating the same
Implementation Method 2
reacting the product of step 1 with a (C1-20 alkyl) amine
Implementation Method 3
subjecting the product of step 3 to a high-speed homogenization
Implementation Method 4
subjecting the product of step 4 to sonication or a high-pressure homogenization
Implementation Method 5
whereby exfoliating the graphite intercalation compound
Implementation Method 6
heat-treating the same
Implementation Method 7
magnetic particles in the form of FeOx are naturally formed
Data Source
AI summary
The present invention relates to a method for preparing a magnetic iron oxide-graphene composite, a magnetic iron oxide-graphene composite prepared thereby and a composition for electromagnetic wave shielding including the same, and since graphene is prepared from a stage 1-GIC using FeCl3, magnetic particles in the form of FeOx are naturally formed on the surface of graphene during the preparation process. In addition, a magnetic material is formed on the surface of graphene while the defects of graphene are minimized, and thus the magnetic iron oxide-graphene composite prepared according to the present invention can be useful as an electromagnetic wave absorber.