A Keto-enol Interpretation of the Surface Acidity of Carbon Black 'Spheron 9'

Surface acidity of carbon black 'Spheron 9' has been studied using bases of different strengths. Three type of acidic groups have been proposed to exist on the surface of 'Spheron 9'. The one which showed maximum decomposition in the lOO-3000C temperature range and which was neu­tralized with sodium bicarbonate only was thought to be either physically adsorbed CO2 or some .stro~ acidic CO2 evolving group such as carboxyl group. The other group which was totally elimi­nated at about 7000C and which was neutralized with aqueous sodium hydroxide and the stronger bases, but not with sodium bicarbonate was suggested to be a weakly acidic CO evolving f-Iactonic group. The third group which remained in appreciable quantity even by degassing ?he carbon at 7000C and which was neutralized with the stronger bases and with alcoholic potassium hydroxide and sodium hydroxide but not with aqueous sodium hydroxide and sodium bicarbonate was thought to be a weakly acidic CO evolving keto-enol group. The keto-enol group has been found to be the major group on the surface of 'Spheron 9' 

M ARSALA KHAN ,W KEMP ,