People

Research Scientist – Dr. Diego Muriel Delgado 

Project Supervisor  – Dr. Joseph Katz

Introduction

Complementing the study of emulsification by mechanical mixing, our laboratory has recently explored the emulsification of oil slicks from different origins by periodic exposure to waves over a prolonged period (see sample data in Figure 2). In particular, we have studied the emulsification of two oils by waves (ANS and Hibernia) for a period of 14 days. Preliminary results show that ANS emulsifies water faster than Hibernia oil, as is evident from the differences in the area covered with water droplets in Figures 3a and b. These tests correspond to emulsion samples collected after 4 days of periodic breaking waves impinging continuously on the oil slicks. Consequently, the viscosity of ANS is at least three times higher than that of Hibernia (Figure 2d). Additionally, photo-oxidation causes faster water emulsification, and increases the characteristic water droplet sizes and volume fraction. As a result, the viscosity of the photo-oxidized Hibernia oil-based emulsions is higher (Figure 2c and d). These trends are consistent with the empirical relationships between the emulsion morphology and its viscosity.

 

Figure 2. Emulsification of oil by breaking waves: a to c) Fluorescent light microscopy for emulsions based on Hibernia, ANS, and Hibernia with photo-oxidation, respectively. d) emulsion viscosity normalized by that of the fresh crude oil as a function of shear rate.