Metal-free anti-biofouling coatings: the preparation of silicone-based nanostructured coatings via purely organic catalysis

Rosica Mincheva,Alexandre Beigbeder,Michala E Pettitt,Maureen E Callow,James A Callow,Philippe Dubois

doi:10.1080/20550324.2016.1190167

Rosica Mincheva, Alexandre Beigbeder + Show 4 more

Open Access

https://doi.org/10.1080/20550324.2016.1190167

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Journal: Nanocomposites	Publication Date: Apr 2, 2016
Citations: 4	License type: open-access

Affiliation: University of Birmingham, University of Mons

Abstract

The successful formulation of two-part condensation-curing silicone materials via purely organic catalysis is here developed and investigated as fouling-release coating. Several non-toxic organic catalysts and their ‘onium’ salts were studied as potential purely organic catalysts on the silicone condensation reaction but also on the properties of the resulting cured resins. The trifluoroacetic acid was pointed suitable for the production of condensation-curing silicone coatings. To assess favorable fouling-release properties, multi-wall carbon nanotubes (0.05–0.2 wt-%) were added to the resin. Interestingly, the catalytic activity of the trifluoroacetic acid proved not affected by the presence of the nanocharge. The properties of the coatings prepared using 0.1 wt-% acid revealed constant degree of crosslinking independently of the carbon nanotubes loading and pronounced surface nanostructuring suitable for fouling release. This final property was tested against Ulva linza sporelings and revealed that the coatings are highly suitable for fouling-release applications.

Highlights

Marine biofouling, the settlement and colonization of microand macro-organisms on submerged surfaces is a major problem in the maritime and aquaculture industries with shipping, infrastructure, and scientific monitoring equipment being adversely affected.[1,2,3] For ships, marine biofouling may result in up to an 86% penalty in power output,[4] decreased vessel speed, an increased fuel consumption of up to ~40%,2 elevated dry-dock cleaning expenses, hull corrosion, and loss of hull strength.[3]
This study describes the preparation of new metal-free carbon nanotube-based poly(dimethyl siloxane) (PDMS) nanostructured coatings via purely organic catalysis and discusses their applicability to the strategy of fouling release
The formulation of an applicable condensation curing-PDMS material via purely organic catalysis was targeted in this research

Summary

Introduction

The settlement and colonization of microand macro-organisms on submerged surfaces is a major problem in the maritime and aquaculture industries with shipping, infrastructure, and scientific monitoring equipment being adversely affected.[1,2,3] For ships, marine biofouling may result in up to an 86% penalty in power output,[4] decreased vessel speed, an increased fuel consumption of up to ~40%,2 elevated dry-dock cleaning expenses, hull corrosion, and loss of hull strength.[3]. The most common mode-of-action of AFPs is based on the slow release of biocide with time. Such coatings are described as self-polishing (erode with time) and possess excellent antifouling properties.[5] Introduced in the late 1950s, commercial AFPs with the broad-spectrum biocide tributyltin were banned in 2008 by the IMO due to their high toxicity toward non-target species.[6] In response, industry has reacted by replacing tin-containing compounds with zinc or copper systems, which may be toxic toward non-target aquatic organisms.[7] One alternative to AFPs is biocide-free[8] fouling-release coatings (FRCs). Based mainly on fluorine or silicone-containing formulations, these low-adhesion coatings promote low adhesion/removal of organisms by hydrodynamic forces as a result of their low elastic modulus and surface energy, but may disrupt marine organism settlement by the formation of a hydrated layer close to their surface.[9]

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