Probing Interfacial Structure and Dynamics of Model and Natural Asphaltenes at Fluid-Fluid Interfaces

Area of Science:

• Colloid and Surface Science
• Petroleum Chemistry
• Materials Science

Background:

• Asphaltenes dictate crude oil interfacial behavior, but their complex molecular structure hinders understanding of structure-property relationships.
• Existing research lacks a unified view of asphaltene interfacial dynamics and thermodynamics.

Purpose of the Study:

• To connect asphaltene interfacial morphology with interfacial dynamics.
• To establish fundamental structure-property relationships using model compounds.
• To investigate asphaltene behavior at air-water and decane-water interfaces.

Main Methods:

• Simultaneous interfacial dilatational deformation and microscopic structural imaging analysis.
• Study of both natural asphaltene samples and a model asphaltene compound.
• Analysis of systems at air-water and decane-water interfaces.

Main Results:

• Observed deviations between isotropic and anisotropic deformations reveal how asphaltene dynamics influence interfacial morphology and thermodynamics.
• Model asphaltenes demonstrate high surface pressure activity and aggregation character, offering insights into natural asphaltenes.
• A proposed aggregation mechanism links microscopic and millimetric aggregates for both model and natural asphaltenes.

Conclusions:

• Fundamental structure-property relationships can be elucidated using model asphaltene compounds.
• Understanding asphaltene aggregation mechanisms is crucial for predicting interfacial behavior.
• This work provides a framework for linking molecular structure to macroscopic interfacial properties.