Marine biofouling
negatively impacts industries with off-shore
infrastructures, such as naval, oil, and aquaculture. To date, there
are no ideal sustainable, economic, and environmentally benign solutions
to deal with this phenomenon. The advances achieved in green solvents,
as well as its application in different industries, such as pharmaceutical
and biotechnology, have promoted the emergence of deep eutectic systems
(DES). These eutectic systems have applications in various fields
and can be revolutionary in the marine-based industrial sector. In
this study, the main objective was to investigate the potential use
of hydrophobic DES (HDES) based on menthol and natural organic acids
for their use as marine antifouling coatings. Our strategy encompassed
the physicochemical characterization of different formulations, which
allowed us to identify the most appropriate molar ratio and intermolecular
interactions for HDES formations. The miscibility of the resulting
HDES with the marine coating has been evaluated and proven to be successful.
The Men/OL (1:1) system proved to be the most promising in terms of
cost-production and thus was the one used in subsequent antifouling
tests. The cytotoxicity of this HDES was evaluated using an in vitro
cell model (HaCat cells) showing no significant toxicity. Furthermore,
the application of this system incorporated into coatings that are
used in marine structures was also studied using marine species (Mytilus edulismussels andPatella
vulgatalimpets) to evaluate both their antifouling
and ecotoxicity effects. HDES Men/OL (1:1) incorporated in marine
coatings was promising in reducing marine macrofouling and also proved
to be effective at the level of microfouling without viability impairment
of the tested marine species. It was revealed to be more efficient
than using copper oxide, metallic copper, or ivermectin as antifouling
agents. Biochemical assays performed on marine species showed that
this HDES does not induce oxidative stress in the tested species.
These results are a strong indication of the potential of this HDES
to be sustainable and efficiently used in marine fouling control technologies.