Encapsulation of active agents (corrosion inhibitors, pH indicators) has been described as a
promising approach to impart controlled release and limit detrimental interactions between the
active agents and the coating matrix. Mesoporous silica nanocapsules (SiNC) are engineered
materials widely used for encapsulation. One synthesis route reported in the literature for these
materials is based on a one-step emulsification process (oil-in-water microemulsion), using
hexadecyltrimethylammonium bromide (CTAB) as emulsifier of the microemulsion. However, CTAB is also
a source of toxicity to marine species, thus its replacement by other surfactants has been
suggested.
This work describes the synthesis of new silica nanocapsules loaded with corrosion inhibitor 2-
mercaptobenzothiazol (MBT) by using a gemini surfactant as a potential replacement for CTAB. The
obtained nanocapsules were characterized by scanning electron microscopy (SEM), dynamic light
scattering (DLS) and BET for pore size and surface area analysis. All the parameters were compared
with those for nanocapsules based on CTAB, as well as ecotoxicity in relevant marine species.
Nanocapsules were characterized by electrochemical techniques for anticorrosion applications,
showing that they can be a prospective, new generation of nanomaterials with lower toxicity.