Graphite Oxide's Flammability Explained

A common contaminant in graphite oxide renders the material highly flammable, according to a study published in Advanced Functional Materials (DOI: 10.1002/adfm.201000736). The report’s findings identify key safety issues pertaining to a commonly studied material and might clear up confusion regarding the flammability or flame resistance of some carbon-based materials. Academic and industrial researchers often use a well-established method for oxidizing and exfoliating graphite with concentrated 
acids and potent oxidizers such as KMnO₄. The method yields graphite oxide, which can be readily reduced to graphene. While probing graphite oxide’s exothermicity, Northwestern University materials scientists Franklin Kim, Jiayan Luo, Jiaxing Huang, and coworkers found that in the solid state, the material can undergo self-sustaining deoxygenation that propagates throughout the entire sample. In contrast, the graphenelike products made from graphite oxide—reduced graphite oxide and chemically modified graphene—are highly flame resistant, the team finds. However, the products and especially the graphite oxide starting material become violently flammable when contaminated with potassium salt residues from graphite oxide synthesis, they report.