Ecotossicità e performance foul release di coatings polimerici fotopolimerizzati a base di miscele siliconiche con componenti fluorurati ed ossietilenici.

Biofouling is the settlement and growth of any organisms on man-made structures placed in water. In the case of ships, the adverse effects caused by this biological settlement are well known: the presence of organisms on hulls decreases the range, speed and maneuverability of ships, reduces the time between dry-dockings and increases propulsive fuel consumption by as much as 30%. The need to improve ship performance by limiting the amount of fouling on hulls traces back many centuries. Among all the different solutions proposed throughout the history of navigation, tributyltin self-polishing copolymer paints have been the most successful in combating biofouling on ships. The widespread use of these paints, estimated to cover 70% of the present world fleet, has led to important economic benefits; unfortunately, the TBT-SPC systems affect adversely the environment so legislative restriction for the use of these paints followed shortly after. Current efforts are directed at improving existing, and developing new, nontoxic antifouling coatings; foul-release strategy is considered environmentally friendly because provide fouling protection by minimizing the initial attachment and the strength of attachment through the properties of the coating surface. In this work we present the evaluation of ecotoxicity and foul release performance of novel biocide-free materials which combine low surface energy and low elastic modulus, two of the most important physic-chemical properties of the future generation of foul-release coatings. Polymers were designed and synthesized by an easy and versatile method useful to prepare novel amphiphilic networks by the UV photo-copoplymerization of commercially available (metha)acryloxy functionalized polydimethylsiloxane, polyethylene glycol and perfluorinated macromonomers (Prof. G. Galli's group, Dipartimento di Chimica e Chimica Industriale-Università di Pisa); the replacement of sol-gel process with photo-crosslinking process might result in several advantages, including i) to avoid the use of heavy metal-based catalysts (e.g tin-based) possible sources of toxicity issues ii) reduction in solvent consumption and relative prolonged periods of time for evaporation iii) shorter reaction times, since the photo-curing reaction is generally very fast, occurs at room temperature and does not require heating for the finishing step. In order to assess the ecotoxicity, model organisms (Vibrio fischeri, Dunaliella tertiolecta, Artemia salina) were exposed to a 14 days leaching water of polymers spray-coated on glass slides and different ecotoxicological endpoints were evaluated. Experimental essays were also performed to test the adhesion in static conditions and the adhesion-strenght of target organisms under turbulent flow such as diatom Navicula salinicola and the serpulid Ficopomatus enigmaticus, for which have been set up production techniques of competent larval stages