The Role of Water in the Aggregation of Coal-Derived Asphaltene: Dominance of π-π Interaction

The effect of water to the self-aggregational phenomenon of coal-derived asphaltene (sourced from coal liquefaction plant at CIMFR, Dhanbad, India) has been studied tensiometrically and fluorimetrically in CCl4 medium. Although asphaltene molecule contains small number of hydrophilic groups such as –NH, –SH, and sometimes –OH, the main force behind the aggregation of asphaltene is π-π stacking interaction between the asphaltene molecules. This has been established by showing that critical micelle concentration (CMC) of asphaltene/CCl4 system increases with addition of microquantity of water and also by studying the variation of surface tension (ST) with addition of water to asphaltene solution above its CMC.