2019 AIChE Annual Meeting
(541c) A Continuous Approach to Synthesize Nanoemulsions Via Condensation
Authors
A Continuous approach to synthesize
Nanoemulsions via condensation
In
this work, a new method is presented to make Nanoemulsions
continuously. Typically synthesizing emulsions requires breaking the dispersed
phase by applying a shear force such that obtaining emulsions with narrow size
demands consuming a tremendous amount of energy. In the current method, the
main challenging step of making Nanoemulsions which
is introducing the distinct droplets within the continuous phase is addressed
by Condensation. The predominant advantage stems from the heterogenous
nucleation of water vapor nuclei on the sub-cooled oil-air interface associated
with spontaneous submergence within the oil-surfactant solution. The positive
spreading coefficient of oil prevents droplet growth induced by vapor diffusion
via cloaking while surfactants adsorption at the interface of droplets inhibits
coalescence between the adjacent droplets. The resulting emulsion size strongly
depends on the surfactant amount as well as the time during which condensation
happens. Longer condensation on stagnant oil phase results in larger emulsion
size. Here we introduce a new approach in which the continuous phase undergoes
a constant motion and carries the condensation-obtained emulsion with constant
velocity upon formation. We discuss how surfactant amounts, condensation time,
and motion velocity of the continuous phase affect the emulsion size. We show
how the approach can produce larger quantities of emulsions in an
energy-efficient manner.