Asphaltenes are polyaromatic constituents of fossil fuels (petroleum, tar, coal) that cause several important technical, economic and environmental problems. For instance, their low aqueous solubility and volatility coupled to high affinity to polar surfaces make asphaltenes a major constituent of oil slicks covering shorelines and sea life after oil spills. 

  Asphaltenes are also largely responsible for the poor energy efficiency of tar sands extraction: almost half of hydrocarbons in place are burnt to help produce the remaining half. This effect is partly due to the extreme tar viscosities caused by colloidal asphaltenes, as well as partly due to the ability of asphaltenes to strongly adsorb on polar surfaces and thereby hold tar, sand and water together. Asphaltenes adsorption on polar surfaces is very poorly understood. It has long been suggested that colloidal-like aggregates adsorbed whenever the driving force could not be clearly identified. A new paradigm has been proposed by researchers working together at CCNY and SINTEF based upon the relationship between molecular crowding and interfacial tension: asphaltenes would first adsorb as individual molecular ‘monomers’ due to the electronic properties of their polyaromatic cores. Recent DFT-based simulations in a collaboration between CCNY and LCPQ seem to confirm this conclusion.