Hummers' method
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Hummer's MethodCite error: There are <ref> tags on this page without content in them (see the help page).
Method
The Hummer's Method[1] was developed in 1958 as a safer, faster and more efficient method of producing graphite oxide. Before the method was developed, the production of graphite oxide was slow and hazardous to make, involving the use of concentrated sulfuric and nitric acid. The Staudenmeier-Hoffman-Hamdi method involved the addition of potassium chlorate, introducting more hazards and produced one gram of graphite oxide to ten grams of potassium chlorate.
William S. Hummers and Richard E. Offeman introduced their method as an alternative to the above methods after noting the hazards they poised to workers at the The National Lead Company. Their approach was similar in that it involved adding graphite to a solution of concentrated acid. However, they simplified it to just graphite, concentrated sulfuric acid, sodium nitrate, and potassium nitrate. They also did not have to use temperatures above 98°C and avoided most of the explosive risk of the Staudenmeier-Hoffman-Hamdi Method.
The procedure starts with 100g graphite and 50g of sodium nitrate in sulfuric acid at 66°C which is then cooled to 0°C. 300g of potassium permanganate is then added to the solution and stirred. Water is then added in increments until the solution is approximately 32 liters.
The final solution contains about 0.5% of solids to then be cleaned of impurities and dehydrated with phosphorus pentoxide.
Chemical Equations and Efficiency
Graphite Oxide
Graphite Oxide is a compound of carbon, oxygen, and hydrogen where the there is a ratio between 2.1 to 2.9 of carbon to oxygen. It is also known as graphene oxide when used to form monomolecular sheets.
Modern Variations
See Also
References
- ^ Hummers, William S.; Offeman, Richard E. (March 20, 1958). "Preparation of Graphitic Oxide". Journal of the American Chemical Society. 80 (6): 1339. doi:10.1021/ja01539a017.
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