One Step Forward towards the Development of Eco-Friendly Antifouling Coatings: Immobilization of a Sulfated Marine-Inspired Compound

Abstract

Marine biofouling represents a global economic and ecological challenge and few eco-friendly antifouling agents are available. The aim of this work was to establish the proof of concept that a recently synthesized nature-inspired compound (gallic acid persulfate, GAP) can act as an eco-friendly and effective antifoulant when immobilized in coatings through a non-release strategy, promoting a long-lasting antifouling effect. The synthesis of GAP was optimized to provide quantitative yields. GAP water solubility was assessed, showing values higher than 1000 mg/mL. GAP was found to be stable in sterilized natural seawater with a half-life (DT50) of 7 months. GAP was immobilized into several commercial coatings, exhibiting high compatibility with different polymeric matrices. Leaching assays of polydimethylsiloxane and polyurethane-based marine coatings containing GAP confirmed that the chemical immobilization of GAP was successful, since releases up to fivefold lower than the conventional releasing systems of polyurethane-based marine coatings were observed. Furthermore, coatings containing immobilized GAP exhibited the most auspicious anti-settlement effect against Mytilus galloprovincialis larvae for the maximum exposure period (40 h) in laboratory trials. Overall, GAP promises to be an agent capable of improving the antifouling activity of several commercial marine coatings with desirable environmental properties.

Nature-Inspired Peptide Antifouling Biocide: Coating Compatibility, Field Validation, and Environmental Stability

“…This could be achieved by, for example, microencapsulation of 1 . , Alternatively, methods to immobilize 1 in, or on, a coating could be considered. Immobilization in marine coatings has been successfully applied for the antifouling biocide 4-bromo-2-(4-chlorophenyl)-5-(trifluoro-methyl)-1 H pyrrole-3-carbonitrile (ECONEA) and to nature-inspired synthetic compounds. , …”

“…Immobilization in marine coatings has been successfully applied for the antifouling biocide 4-bromo-2-(4-chlorophenyl)-5-(trifluoro-methyl)-1H pyrrole-3-carbonitrile (ECO-NEA) 51 and to nature-inspired synthetic compounds. 52,53 3.4. Environmental Stability.…”

Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative

“…Previous studies on the incorporation of GBA26 in a PU-based coating system showed that, although GBA26 had maintained AF activity against the settlement of M. galloprovincialis larvae, it was rapidly released from the PU-based marine coating. Therefore, to increase the service life of these coatings, further coating optimization was performed, according to an existing immobilization methodology [ 19 ], which involved the addition of the trimethylolpropane triaziridine propionate (TZA) crosslinker (CL) into the formulation. This aziridine-based crosslinker, widely used in polymeric formulations such as paints, reacts rapidly with nucleophilic functional groups of the compounds (e.g., amines, alcohols), promoting cross-links between different functional additives, and improving their compatibility with the polymeric systems [ 19 ].…”

“…This organism was applied for the assessment of the in vitro AF performance of surfaces and coatings [ 15 , 16 , 17 , 18 ]. Hence, new PU-based coating formulations containing GBA26 aziridine-based crosslinker (CL) to enable higher service life of coatings [ 19 ] were evaluated for P. tunicata biofilm growth ( Figure 1 ), at defined hydrodynamic settings [ 20 ] mimicking a real marine scenario.…”

Microbiologically influenced corrosion—more than just microorganisms

“…Their use is now strictly regulated in certain areas [e.g. EU Biocides Regulation 528/ 2012 (98/8/EC)], prompting the search for effective and environmentally friendly long-term solutions (Loureiro et al 2018 , Ferreira et al 2020 , Vilas-Boas et al 2020 , Ferreira et al 2021 ). Significant advances have been achieved in relevant coating technologies, with work on a range of different properties such as the group of targeted organisms, mechanism of action, bioactive agents, the polymeric matrix, surface structure, environmental surrounding, or even fundamental working principle being conducted (Ferreira et al 2020 , Bhoj et al 2021 , Silva et al 2021 ).…”