▎ 摘　　要

NOVELTY - Obtaining graphene oxide, comprises e.g. mixing lamellar graphite powder having intercalating material separating their structural lamellas with same amount of sodium nitrate, and adding mixture to solution of 98% sulfuric acid under continuous stirring for 1-2 hours, cooling mixture in ice bath to lower its temperature and maintaining at 20-25 degrees C, adding, very slowly, 2-10% of potassium permanganate for up to 1 hour, maintaining stirring to prevent temperature from increasing rapidly and from surpassing an increase of 10%, and removing mixture from the ice bath. USE - The process is useful for obtaining graphene oxide (claimed) which is useful for obtaining nanocomposites with different matrices and for purifying water. ADVANTAGE - The process provides the graphene oxide: with a conversion degree of higher than 90% (claimed); in a simple, rapid, easy and economical manner; and with high purity without graphite debris. The process allows: random distribution of the functional groups on the whole surface; uniform oxidation in the whole material; and greater exposure of the surface of the lamellar graphite to the oxidizing agents that increases the reactivity of the graphite, thus promoting the oxidation of the starting graphite which in turn gives good yields of graphene oxide. DETAILED DESCRIPTION - Obtaining graphene oxide, comprises mixing a powder starting material comprising lamellar graphite having an intercalating material separating their structural lamellas with the same amount of sodium nitrate, and adding the mixture to a solution of 98% sulfuric acid under continuous stirring for 1-2 hours, cooling the mixture in an ice bath to lower its temperature and maintaining at 20-25 degrees C, adding, very slowly, 2-10% of an oxidant comprising potassium permanganate for up to 1 hour, maintaining the stirring to prevent the temperature from increasing rapidly and from surpassing an increase of 10%, removing the mixture from the ice bath, heating it and maintaining it under stirring, until it presents physical properties indicating the formation of graphene oxide, diluting the mixture by slowly adding deionized water, until reaching an increase of at least 30% in volume of the original solution, causing a temperature increase reaching an average of 60 degrees C, leaving the mixture to stand up to 24 hours for completion of the reaction, heating the mixture until reaching a temperature of 95-100 degrees C and maintaining the mixture in that temperature under high stirring, adding water to the mixture, until the solution reaches thrice its original volume, and also adding to the latter a sufficient amount of hydrogen peroxide for completion of the oxidation reaction, purifying the mixture by washing it with hydrochloric acid solution for reducing their pH and subsequently, washing with deionized water for reducing the acids, and filtering and drying the mixture, under vacuum, and at room temperature to obtain the graphene oxide in powder form presenting a conversion degree higher than 90%.