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

Abstract

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.

Keywords:

• Aggregates
• asphaltene
• critical micelle concentration (CMC)
• fluorescence