11 research outputs found
Modification of inkjet printer for polymer sensitive layer preparation on silicon-based gas sensors
Systematic Study of Heavy Oil Emulsion Properties Optimized with a New Chemical Formulation Approach: Particle Size Distribution
The purpose of this research was
to create very polydisperse concentrated
heavy oil-in-water emulsions by optimizing the co-solvents, surfactants,
alkali, and electrolytes in the chemical formulation, with respect
to the droplet size distribution. Novel co-solvents that have shown
superior performance in chemical formulations used for enhanced oil
recovery have been tested. Droplet size distributions that resulted
in a lower emulsion viscosity were determined to have a higher mean
droplet diameter (<i>d</i><sub>32</sub>) and a bimodal droplet
size distribution with a diameter ratio (<i>d</i><sub>32,L</sub>/<i>d</i><sub>32,S</sub>) of > 6 and a volume fraction
(φ<sub>S</sub>/(φ<sub>L</sub> + φ<sub>S</sub>))
of 0.2–0.3, where φ is the volume fraction of the dispersed
phase and the subscripts L and S correspond to the larger and smaller
peaks in the bimodal distribution. We report the effects of various
chemical formulations on the droplet size distribution of heavy oil-in-water
emulsions with a particular emphasis on <i>d</i><sub>32</sub> and, for the first time, the maximum packing fraction (φ<sub>m</sub>) of oil droplets. A novel one-step preparation procedure
is proposed to prepare concentrated multimodal oil-in-water emulsions
with a new chemical formulation approach. We were able to formulate
stable oil-in-water emulsions with φ<sub>m</sub> values as high
as 0.95, which is ∼0.30 higher than the theoretical φ<sub>m</sub> value for random close packed monodisperse spheres (0.64).
We observed the optimal particle size distribution of concentrated
heavy oil-in-water emulsions prepared with co-solvents for maximum
packing at ∼75% of the Na<sup>+</sup> concentration necessary
to reach the oil-in-water to water-in-oil inversion point for anionic
surfactants. An important application of this study is the transport
of heavy oils in pipelines