Using textured PDMS to prevent settlement and enhance release of marine fouling organisms

Abstract

The antifouling efficacy of a series of 18 textured (0.2–1000 μm) and non-textured (0 μm) polydimethylsiloxane surfaces with the profiles of round- and square-wave linear grating was tested by recording the settlement of fouling organisms in the laboratory and in the field by monitoring the recruitment of a multi-species fouling community. In laboratory assays, the diatoms Nitzschia closterium and Amphora sp. were deterred by all surface topographies regardless of texture type. Settlement of propagules of Ulva sp. was lower on texture sizes less than the propagule size, and settlement of larvae of Saccostrea glomerata and Bugula neritina was lower on texture sizes closest to, but less than, the sizes of larvae. After a six month field trial, all textured surfaces lost their deterrent effect; however, the foul-release capabilities of textures were still present. High initial attachment was correlated with most fouling remaining after removal trials, indicating that fouling organisms recruited in higher numbers to surfaces upon which they attached most strongly.

Keywords:

• polydimethylsiloxane
• silicone
• texture
• antifouling
• topography

Acknowledgements

The authors thank M. Cruickshank, J. Hassett, K. Hauser and staff from the Townsville Yacht Club for their continued support over the years as well as P. Southgate for providing S. glomerata larvae and for help with the identification of animals. They would also like to thank S. Askew from the Advanced Analytical Centre at JCU for providing AFM support. The authors also acknowledge the contribution of four anonymous reviewers for their comments on the manuscript. Financial support was provided by CSIRO’s Wealth from Oceans Flagship and Petroleum and Geothermal Research Portfolio. M.J.V. was further supported by a JCU Postgraduate Research Scholarship and a CSIRO Postgraduate Studentship.