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. /articles/88/i30/Graphite-Oxides-Flammability-Explained.html 20100726 A common contaminant in graphite oxide renders the material highly flammable News of The Week 88 30 /magazine/88/8830.html /departments/.html /collections/notw.html Graphite Oxide's Flammability Explained Science & Technology Mitch Jacoby Deliberately contaminating the lower portion of this millimeter-sized strip of graphite oxide with potassium hydroxide causes that portion of the sample to violently burst into flame when a hot tip is brought near the uncontaminated upper portion.
by Mitch Jacoby |
July 26, 2010