Biofouling Inhibition with Grafted Econea Biocide: Toward a Nonreleasing Eco-Friendly Multiresistant Antifouling Coating

Abstract

The most effective strategies to control biofouling release toxic and persistent agents into the aquatic environment causing environmental concerns and leading to the implementation of more strict international legislation. This work presents recent progress on an innovative eco-friendly antifouling approach based on the isocyanate-functionalized Econea biocide allowing its chemical fixation in polymeric frameworks, namely, in a foul-release marine coating. The antifouling potential of the generated nonbiocide release coatings for both antimicrobial and long-term marine anti-biofouling applications is reported here for the first time. Inhibition growth effects against Methicillin-resistant Staphylococcus aureus bacterium obtained for Econea-based coatings reveal a decrease in the number of colony forming units (CFUs) up to 5 orders of magnitude in 6 h of exposure when compared to the free bacteria. The growth and the viability profiles (CFU/mL) revealed also bacteriostatic effects. The nonbiocide release coatings were able to minimize considerably the biocide release, becoming 10-fold lower than in a conventional releasing system and providing long-lasting antifouling effects, more than two years, under real seawater conditions. Both antifouling effects follow a nonbiocide release strategy leading to a minimization of the environmental impact of the biocidal coatings and the selective pressure on the microorganisms that evolve treatment resistance.

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

“…To evaluate the potential of GAP as an AF agent in real coating systems, this compound was, for the first time, directly incorporated (DI) and chemically immobilized (CI) into two representative marine coatings: PDMS and PU-based coatings. The direct incorporation allows us to assess the feasibility of the new synthetized GAP as an AF agent in conventional release AF coating systems, while the chemical immobilization strategy demonstrates the potential of GAP to be grafted in polymeric non-release coating systems [ 36 ], thus promoting long-lasting effects in the generated protective coating compared with the short lifetime of the conventional releasing systems.…”

“…PVC-coated plates (3.5 × 6 cm) with the developed PU and PDMS polymeric coating systems, with or without immobilized GAP, were submerged in ASW for a period of 45 days, using a prior optimized stirring method [ 36 ]. The average pH of the ASW during the tests was around 8 ± 0.3, and the temperature ranged from 18 to 21 °C.…”

Antimicrobial Ceramic Filters for Water Bio-Decontamination

“…The biocides structural characterization was performed by standard techniques such as Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The isocyanate-free content on the functional biocide derivative was determined by an adapted procedure from the standard ASTMD2572, already described in previous publications [24,35].…”

Towards cost‐effective biofouling management in salmon aquaculture: a strategic outlook

“…2019; Ferreira et al . 2020). While Econea‐based coatings designed for finfish aquaculture do not yet show the same long‐lasting performance (Bloecher & Floerl 2020), the antifouling system innovations around Econea illustrate the potential of novel antifouling approaches.…”

“…One recent example is the development of 'nonbiocide-release' coatings where the novel, metal-free biocide Econea is immobilised in foul-release coatings using covalent bonds. During trials in temperate and tropical environments, long-lasting protection (>2 years) was achieved, with no or minimal associated release of biocide (Silva et al 2019;Ferreira et al 2020). While Econea-based coatings designed for finfish aquaculture do not yet show the same long-lasting performance (Bloecher & Floerl 2020), the antifouling system innovations around Econea illustrate the potential of novel antifouling approaches.…”