Phospholipid-mediated exfoliation as a facile preparation method for graphene suspensions

Area of Science:

• Materials Science
• Nanotechnology
• Biochemistry

Background:

• Graphene production often involves complex and costly methods.
• Developing 'green' and scalable synthesis routes for graphene is crucial.
• Functionalizing graphene for biological applications requires compatible coatings.

Purpose of the Study:

• To develop a simple, inexpensive, and environmentally friendly method for producing graphene in colloidal dispersion.
• To investigate the role of phospholipid fluidity in graphene exfoliation and stabilization.
• To assess the suitability of the produced graphene for biological applications.

Main Methods:

• Ultrasonic exfoliation of graphene in aqueous solution.
• Use of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) as a dispersing agent.
• Characterization using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and atomic force microscopy (AFM).

Main Results:

• Successfully prepared aqueous graphene dispersions predominantly composed of few-layer graphene flakes.
• Demonstrated that the fluidity of phospholipid hydrophobic chains (like in DOPC) is essential for effective graphene dispersion.
• Showed that stiffer phospholipids (DPPC, POPC) can disperse graphene when combined with cholesterol.
• Confirmed DOPC coating renders graphene flakes compatible with biological environments.

Conclusions:

• A novel, green, and cost-effective method for graphene dispersion using ultrasonic exfoliation and DOPC has been established.
• Phospholipid chain fluidity is a key factor in mediating graphene exfoliation and stabilization.
• The developed method offers a pathway for producing biocompatible graphene for various applications.