Throughout the cold oxidation process of pure graphite, an increase of the basal spacing is produced which allows the penetration of polar liquids between the layers of the graphitic acid formed during the oxidation process. A study has been made of the retention of ethylene-glycol in samples of graphitic acid, oxidized to different degrees, obtained from natural mineralogical graphite and from an artificial graphite. The interlayer surface area has been determined once we know that the sorbate forms a monolayer, and supposing that the area covered by each molecule of the sorbed ethyleneglycol is 22A2.
The density of the sorbed ethylene-glycol has been determined from the amount of sorbate retained and from the increase of the basal spacings.
The values of the interlayer surface area of the most oxidized samples agree with those of the theoretical interlaminar surface area determined by X-rays and composition, and with those determined from the density of ethylene-glycol in benzene and the c parameter.
Finally, the retention of ethylene-glycol by different samples tells us how the graphite is transformed into graphitic acid, which gives us an indirect method of determining the specific velocity of the oxidation process of graphite at 0°C.