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Synthesis and Functionalization of 3D Nano-graphene Materials: Graphene Aerogels and Graphene Macro Assemblies
Published on: November 5, 2015
Preparation of covalently functionalized graphene using residual oxygen-containing functional groups
Min-Chien Hsiao1, Shu-Hang Liao, Ming-Yu Yen
1Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
ACS Applied Materials & Interfaces
|October 19, 2010
Summary
Directly functionalizing graphene via ring-opening reactions preserves its structure, enhancing stability. This method avoids defects common in free radical functionalization, yielding stable graphene dispersions.
Area of Science:
- Materials Science
- Nanotechnology
- Surface Chemistry
Background:
- Graphene fabrication via thermal exfoliation often leaves residual epoxide groups.
- Covalent functionalization is crucial for tailoring graphene properties and applications.
- Traditional free radical functionalization can introduce structural defects.
Purpose of the Study:
- To investigate a direct ring-opening reaction for covalently functionalizing graphene.
- To compare the defect profile and stability of directly functionalized graphene with traditional methods.
- To assess the impact of functionalization on graphene's structural integrity and thermal stability.
Main Methods:
- Thermal exfoliation of graphene.
- Direct ring-opening reaction with amine-bearing molecules.
- Characterization using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM).
- Thermogravimetric analysis (TGA) for thermal stability assessment.
- Dispersion stability tests in organic solvents.
Main Results:
- Amine-bearing molecules were successfully covalently grafted onto graphene via epoxide ring-opening.
- Characterization confirmed covalent attachment without significant additional surface damage.
- Graphene dispersions exhibited long-term homogeneous stability.
- Direct functionalization resulted in fewer defects compared to free radical methods.
- Thermogravimetric analysis indicated enhanced thermal stability for both grafted molecules and graphene.
Conclusions:
- Direct ring-opening functionalization is an effective method for covalently modifying graphene.
- This approach preserves graphene's intrinsic structure, minimizing defects and enhancing stability.
- The improved structural integrity translates to superior thermal stability and stable dispersions for practical applications.
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