Preparation of Graphitic Oxide

Abstract

The preparation of graphitic oxide by methods described in the literature is time consuming and hazardous. A rapid, relatively safe method has been developed for preparing graphitic oxide from graphite in what is essentially an anhydrous mixture of sulfuric acid, sodium nitrate and potassium permanganate. Introduction Graphitic oxide, sometimes called graphitic acid, has been known for almost a century. It* was first prepared by Brodie2 34in 1859 by repeated treatment of Ceylon graphite with an oxidation mixture consisting of potassium chlorate and fuming nitric acid. Since then, many other procedures have been devised for forming graphitic oxide, nearly all dependent upon strong oxidizing mixtures containing one or more concentrated acids and oxidizing materials.3-6 The methods most commonly used at the present time are the original Brodie synthesis and one described by Staudenmaier,6 in which the graphite is oxidized in concentrated sulfuric and nitric acids with potassium chlorate. Recent workers in the field such as Hofmann and Frenzel5 and Hamdi7 using the Staudenmaier method found the process time consuming and hazardous. The Stauden-maier-Hofmann-Hamdi method involved the addition of potassium chlorate to a mixture of concentrated sulfuric acid, concentrated (63%) nitric acid and graphite. The potassium chlorate was stirred slowly and carefully into the mixture over a period of one week with cooling. The chlorine dioxide evolved was removed with an inert gas