(465g) Probing Interfacial Structure and Dynamics of Asphaltenes and Model Asphaltenes at Fluid-Fluid Interfaces

Authors: 
Fajardo-Rojas, J. F., Universidad de los Andes
Pradilla, D. C., Universidad de los Andes
Alvarez, O. A., Universidad de los Andes
Samaniuk, J. R., Colorado School of Mines
Asphaltenes are highly surface-active components of crude oil that influence interfacial properties, and these properties are influential to processes such as enhanced oil recovery and crude oil transport. Asphaltenes are also a complex mixture of various molecular structures that make it challenging to investigate connections between interfacial properties and molecular structure. Consequently, these connections remain unclear, a hindrance in the development of physical models of the behavior of asphaltenes that would facilitate better thermodynamic modelling approaches, proper design of enhanced oil recovery techniques, and improvement of crude oil transport technologies. Several groups have reported on the interfacial behavior of asphaltenes, but a unified picture of both interfacial dynamics and thermodynamics is still missing. We seek to establish connections between asphaltene interfacial morphology and interfacial dynamics by combining interfacial dilatational deformation with microscopic structural imaging analysis. Understanding the behavior of natural asphaltene samples is made challenging by the inherent molecular variability. Therefore, we have also studied the behavior of model asphaltene molecules in an effort to draw fundamental structure-property relationships. We will present experimental results of simultaneous interfacial deformation and microscopy in systems of natural and model asphaltenes at air-water and oil-water interfaces. We will discuss how the dynamics of natural asphaltenes affects their morphological and thermodynamic state at air-water and oil-water interfaces, and indicate where model asphaltenes behavior can help us to understand the behavior of natural asphaltenes.