Date of Award
M.S. in Engineering Science
This study examines the ability of CNC to stabilize crude o/w Pickering emulsions. The effects of concentration of CNC, ionic strength of the aqueous phase, volume fraction of crude oil to water, and the presence of divalent ions on the stability of crude o/w emulsions were examined. Emulsions stabilized with different concentrations of CNC vary from 0.1 to 1.0wt% were prepared and examined by visual assessment for creaming analysis and microscopic pictures to analyze droplet size and size distribution. Low concentration of CNC as 0.1wt% didn’t help with forming stable emulsions. As the concentration of CNC stabilized the emulsions increased, the stability of emulsions over time increased because of the ability of CNC particles to fully cover and pack the oil water interface and therefore prevent coalescence. Samples were analyzed and the change in stability of emulsions upon storage was studied by analyzing microscopic pictures and by visual assessment of creaming behavior through a period of time up to 32 hours. Emulsions were prepared with different ionic strength of NaCl varying from 0.3 to 1.9M. Solutions with higher ionic strength formed more stable emulsions against coalescence by decreasing droplet diameter and the rate of growth of droplets with time. On the other hand, higher ionic strength showed faster creaming and a more creamed aqueous phase. API brine and Synthetic seawater stabilized emulsions showed less stability of emulsions due to the presence of divalent ions Ca2+ and Mg2+ ,which may reduce repulsive forces between droplet and cause coalescence.
Alazzam, Omayma, "Cellulose Nanocrystals as 'Green' Emulsifiers Stabilized Crude Oil in Water Emulsions" (2019). Electronic Theses and Dissertations. 1531.