GAWRYS, KEITH LOUIS. How Asphaltenes Aggregate: Role of Chemistry and Solvent. (Under the direction of Peter K. Kilpatrick) Asphaltenes from three crude oils were separated on a preparatory-scale into 20 30 discrete subfractions by sequential precipitation from mixtures of n-heptane and toluene. The earliest fractions precipitated were characterized by lower than average aromaticity and atomic ...

The Taguchi design of experiments (DOE) approach is adopted here to evaluate the impact ofeffective factors such as nanoparticles type, nanoparticles to model solution mass ratio, asphaltenestructure, and temperature on asphaltene adsorption equilibrium. Herein, the toluene-asphaltenesolution model is applied. Three commercially nanoparticles (SiO2, Al2O3, and TiO2) are used.<...

The molecular properties of asphaltenes have been the subject of uncertainty in the literature; in particular the molecular architecture is still a matter of debate. Some literature reports provide evidence that the contrast of petroleum asphaltenes versus coal-derived asphaltenes is useful for understanding the governing principles of asphaltene identity. Here, we employ fluorescence correlati...

Asphaltene and smaller aromatic molecules tend to form linear nanoaggregates in bitumen. Over the years bitumen undergoes chemical aging and during this process, the size of the nanoaggregate increases. This increase is associated with an increase in viscosity and brittleness of the bitumen, eventually leading to road deterioration. This paper focuses on understanding the mechanisms behind nano...

We study chemical aging in "Cooee bitumen" using molecular dynamic simulations. This model bitumen is composed of four realistic molecule types: saturated hydrocarbon, resinous oil, resin, and asphaltene. The aging reaction is modelled by the chemical reaction: "2 resins → 1 asphaltene." Molecular dynamic simulations of four bitumen compositions, obtained by a repeated application of the aging ...