Antifouling agent release from marine coatings-ion pair formation/dissolution for controlled release

摘要

In marine coatings, the ability to sustain constant release of antifouling agents (AFA(s)) over a long period of time has become increasingly important. One efficient approach to prevent that diffusion depletes the paint film's antifouling activity is to adsorb the AFA strongly to a specie with low translational mobility, such as a high molecular weight polymer. Therefore, the AFA, Medetomidine, was adsorbed onto a sulfonated poly styrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SDPS) generating a Medetomidine-SDPS ion pair in an organic solvent. The interaction was investigated by H-1 NMR in butanol (BuOH-d(10)) and on solid surfacesby the quartzcrystal microbalance with dissipation monitoring technique (QCM-D) in two different solvents, seawater and o-xylene. From the NMR studies in butanol (BuOH-d(10)), a strong interaction between Medetomidine and SDPS was observed. From the QCM-D measurements, differences in affinity between Medetomidine and the SDPS was observed when changing from seawater to o-xylene. In seawater, the interaction was weak and displayed a large degree of reversibility compared to in o-xylene, where the interaction was strong and almost irreversible. Different swelling behaviour was also observed at the solid surfaces depending on the solvent used with o-xylene exhibiting the largest swelling of the polymer layer. (C) 2006 Elsevier B.V. All rights reserved.