Interfacial Rheology
Interfacial rheology plays an important role in several processes relating to pharmaceutical, food and petroleum industries. For example, in the oil and gas industry, the stability of water-in- crude oil emulsions or the lack thereof can result in severe operational and economic challenges pertaining to flow assurance and separation processes. Asphaltenes, for example, are high molecular weight aromatic hydrocarbons that are known to be natural stabilizing agents for water-in- crude oil emulsions. They adsorb at the water-oil interface, reduce interfacial tension and form rigid films that hinder coalescence of dispersed water droplets; an undesirable phenomenon in separation processes as it increases the transportation and refining costs. The stability of water-in-crude oil emulsions is largely controlled by the mechanical strength and viscoelasticity – or the so-called interfacial rheological properties - of the interface. Therefore, a deep understanding of the mechanisms by which this interface can be destabilized is essential for surface facility operators for the design and optimization of successful separation processes.