<p>Janus
nanoparticles have applications in many fields. Particularly, the oil industry
is interested in applying them for enhanced oil recovery. Within this context,
there is a need to understand the influence of the factors involved in the
formulation of crude oil type emulsions over their properties and rheological
behavior. In this contribution, spherical SiO<sub>2</sub> Janus nanoparticles
of two different sizes were synthesized and used as surfactants for the
formulation of aqueous emulsions with two model oils: namely, squalane and
vacuum gas oil. Factorial experiments were designed and made to analyze the
effects of the particle size of the Janus nanoparticles, the water content, the
emulsification energy, and of the second and third order interactions between
these variables over the droplet size distributions, polydispersity, and
rheological profiles of the emulsions. On the one hand, it was found that the
used Janus nanoparticles produced either water in oil (for vacuum gas oil) or
oil in water (for squalane) depending on
the chemistry of the oil phase. On the other hand, it was demonstrated that
non-additive factors play an important role over the properties of the
emulsions; especially in the case of the water in oil ones. These effects also
implied non-additive correlations between the droplet size distributions of the
emulsions and their rheological behavior. Therefore, this work demonstrates
that simpler linear relationships do not suffice for finding the best
conditions for formulating crude oil type emulsions aimed for applications such
as enhanced oil recovery.</p>