Patent ID: 8486302

Claim:
A process for preparing a graphite oxide while purging chlorine dioxide, the process comprising steps of: (a) providing an adjustable-flow source of purge gas and a reaction vessel defining a purge gas inlet and a purged gas outlet, wherein the reaction vessel contains a headspace and a reaction mixture comprising the following starting materials: a sulfuric acid, a nitric acid, a first amount of aqueous sodium chlorate, and graphite, wherein the reaction mixture is in fluid communication with the headspace of the reaction vessel and the adjustable-flow source of purge gas is in sequential fluid communication with the purge gas inlet, headspace, and purged gas outlet of the reaction vessel; (b) allowing the reaction mixture to react, at a reaction running temperature of 0 degrees Celsius or higher and for a reaction running time of 30 hours or less, to form graphite oxide and chlorine dioxide gas, and some of the chlorine dioxide gas to migrate into the headspace of the reaction vessel; (c) purging with a purge gas at least some of the chlorine dioxide gas from the headspace and out of the reaction vessel via the purge gas outlet by sequentially flowing the purge gas at an adjustable flow rate from the adjustable-flow source of purge gas through the purge gas inlet, into the headspace of the reaction vessel, and out of the reaction vessel via the purged gas outlet; and (d) separating the graphite oxide from the reaction mixture to give an isolated graphite oxide; the process further comprising a step of monitoring in real-time concentration of the chlorine dioxide gas in the headspace of the reaction vessel and adjusting the flow rate of the purge gas so that the concentration of the chlorine dioxide gas in the headspace of the reaction vessel is less than 10% during step (b).