The influence of low surface energy materials on bioadhesion — a review

Investigations on the adhesion of a diverse range of biological systems including proteins, tissues, microbes, algae and invertebrates all indicate that minimal long-term adhesion is associated with surfaces having initial surface tensions between 20 and 30 dynes/cm (mN/m), i.e. low energy surfaces. However, all surfaces rapidly become modified on immersion in natural waters through the adsorption of ‘conditioning films’, which may influence subsequent adhesive events associated with the permanent attachment of organisms. In this review the various methods which have been used to measure the strength of attachment of both micro- and macrofouling to surfaces will be outlined and results presented for substrata with a range of surface energies. Data will be presented which show that surface energy can elicit different responses in different organisms. For most organisms, minimal adhesion is associated with low surface energy. Silicone elastomers and fluoropolymers have received most attention regarding their potential use as foul release coatings. Results on the antifouling performance of these classes of materials will be discussed.