History and Preparation
Graphite oxide was first prepared by Oxford chemist Benjamin C. Brodie in 1859, by treating graphite with a mixture of potassium chlorate and fuming nitric acid. In 1957 Hummers and Offeman developed a safer, quicker, and more efficient process, using a mixture of sulfuric acid H2SO4, sodium nitrate NaNO3, and potassium permanganate KMnO4, which is still widely used (as of 2009).
Recently a mixture of H2SO4 and KMnO4 has been used to cut open carbon nanotubes lengthwise, resulting in microscopic flat ribbons of graphene, a few atoms wide, with the edges "capped" by oxygen atoms (=O) or hydroxyl groups (-OH).
Graphite oxide has also been prepared by using a "bottom-up" synthesis method (Tang-Lau method) in which the sole source is glucose, the process is safer, more easy, and more environmentally friendly compared to traditionally “top-down” method, in which strong oxidizers must be involved. Another important advantage of Tang-Lau method is thickness controllable ranging from monolayer to multilayers by simply adjusting growth parameters.
Read more about this topic: Graphite Oxide
Famous quotes containing the words history and, history and/or preparation:
“History and experience tell us that moral progress comes not in comfortable and complacent times, but out of trial and confusion.”
—Gerald R. Ford (b. 1913)
“While the Republic has already acquired a history world-wide, America is still unsettled and unexplored. Like the English in New Holland, we live only on the shores of a continent even yet, and hardly know where the rivers come from which float our navy.”
—Henry David Thoreau (1817–1862)
“With memory set smarting like a reopened wound, a man’s past is not simply a dead history, an outworn preparation of the present: it is not a repented error shaken loose from the life: it is a still quivering part of himself, bringing shudders and bitter flavours and the tinglings of a merited shame.”
—George Eliot [Mary Ann (or Marian)