Environmental Remediation of Deepwater Oil Spills: The Effects of Surfactant Structure on Oil Droplet Formation

Abstract

This thesis examines surfactant performance in light of the catastrophic events of the Deepwater Horizon platform explosion and oil spill that occurred in 2010, focusing on structural properties that alter the surfactants ability to lower the surface tension, and effectively increase the oil droplet surface area available for biodegradation. The effects of chain length, branching, and hydrophobic character are examined via microfluidic, emulsion, and pendant drop experiments. This work demonstrates that shorter surfactant chains lead to a more uniform dispersion, as well as reduced droplet size when compared to longer chains of the same structure. Furthermore, branched surfactants exhibit a greater polydispersity and larger droplets when compared to similarly sized, linear molecules. Hydrophobically modified polyacrylic acids (HMPAA) are studied and while hydrophobic chain length itself had a minimal effect, an increase in frequency of the hydrophobic chains resulted in greater dispersity. Given the transportation industry’s current dependence on oil and the scale at which deepwater drilling is occurring, this thesis is of financial and environmental importance to better understanding oil spill cleanup technology and further developing novel surfactants.