Antifouling character of ‘active’ hybrid xerogel coatings with sequestered catalysts for the activation of hydrogen peroxide

Abstract Halide-permeable xerogel films prepared from sols containing 50 mol% aminopropyltriethoxysilane (APTES)/50 mol% tetraethoxysilane (TEOS) or 10 mol% APTES/90 mol% TEOS and 0.015 M selenoxide or telluride catalyst in the sol gave reduced settlement of cypris larvae of the barnacle Balanus amphitrite and larvae of the tubeworm Hydroides elegans in the presence of artificial seawater (ASW) and hydrogen peroxide (5–100 μM) relative to glass controls. Settlement of Ulva zoospores was lower on both the 50 mol% APTES/50 mol% TEOS and 10 mol% APTES/90 mol% TEOS xerogel formulations in comparison with glass controls with or without the added catalyst. The 50 mol% APTES/50 mol%TEOS xerogel containing telluride catalyst gave reduced settlement of Ulva zoospores in the presence of 100 μM H2O2 in ASW compared with the same coating without added peroxide. Scanning electron microscopy and XPS data suggest that exposure to H2O2 does not lead to chemical or morphological changes on the xerogel surface. Keywords: active xerogelshydrogen peroxidebiofoulingalgae Ulva barnacles Balanus amphitrite tubeworms Hydroides elegans Acknowledgements The authors thank the Office of Naval Research for supporting this work through grants to MEC and JAC (award N00014-02-1-0521), MGH (award N00014-05-1-0579), MRD and FVB (award N0014-02-1-0836) and DEW (award N00014-02-0935). The authors also thank Lenora Brewer for her work on the B. amphitrite data sets.