Here’s an easy way to functionalize potassium graphite. The useful reagent potassium graphite (C8K) is formed by the intercalation of potassium atoms between graphite sheets. The goal of W. E. Billups and co-workers at Rice University (Houston) was to use this material as a substrate for synthesizing soluble derivatives of graphite nanoplatelets. They treated freshly prepared C8K with 1-iodododecane to produce dodecylated graphite that was soluble in common solvents such as CHCl3 and benzene.
The authors achieved water solubility by treating the graphite surface with 5-bromovaleric acid, followed by reaction with amine-terminated poly(ethylene glycol) (PEG) chains. FTIR analysis confirmed the structure of the carboxylic acid intermediate and the final amide group that coupled the graphite surface to the polymer.
The authors determined that the PEG-modified graphite nanoplatelets have an average size of ~0.1 μm. They used electron microscopy to confirm that, as in single-walled carbon nanotubes, there are “bumps” along the sidewalls of the graphite structures that indicate surface functionalization. These materials may be useful as fillers in manufacturing polymer composites. (Angew. Chem., Int. Ed. 2007,46,4486–4488; W. Jerry Patterson) Go to top