Optical Properties and Aggregation of Graphene Nanoplatelets

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Graphene nanoplatelets (GNPs) offer unique properties for advanced materials.
• Controlling GNP dispersion and aggregation is crucial for their application.
• Existing methods for GNP dispersion face challenges in scalability and purity.

Purpose of the Study:

• To estimate the optical density of randomly oriented multilayer graphene nanoplatelet (GNP) dispersions.
• To compare calculated and experimental data for GNP dispersions stabilized with surfactants.
• To investigate the transformation of expanded graphite compound (EGC) into GNP aggregates during sonication.

Main Methods:

• Sonication of expanded graphite compound (EGC) in aqueous surfactant solutions.
• Analysis of optical density of GNP dispersions.
• Filtration and washing of GNP aggregates to remove surfactants.
• Comparison of experimental data with calculated optical density values.

Main Results:

• Sonication of EGC in surfactant solutions yields weak GNP aggregates.
• These aggregates can be dispersed in solution upon dilution and agitation.
• Surfactants can be effectively removed by filtration and washing.
• Optical density estimations were validated through comparison of calculated and experimental data.

Conclusions:

• Weak GNP aggregates formed by sonication are amenable to purification and dispersion.
• Concentrated GNP dispersions with purified aggregates are suitable for synthesizing graphene-based nanostructures.
• This method provides a pathway for developing novel graphene-based composite materials.