Raft trial experiments to investigate the antifouling potential of silicone elastomer polymers with added biocide

The antifouling potential of silicone elastomer (SE) polymers and biocide (3-(trimethoxysilyl) pro-pyloctadecyldimethyl ammonium chloride (DC5700)-enhanced silicone polymers was investigated in raft trial studies. An initial short term study (23 d) indicated diatom film attachment to both the control and the biocide enhanced polymer surfaces. Cell viability and dry weight studies indicated a toxic effect and a reduction of fouling on the DC5700 SE polymers compared to the control SE. In a further longer (13 week) study, fouling gradually built up on both surfaces with no significant difference in the dry and ashed weights of fouling on the two surfaces. Fouling on the control surfaces was characterised by a slime film with barnacle and hydroid settlement and on the DC5700 SE surfaces by a mixed fouling community characterised by macroalgal fouling. This study as shown the possibility of incorporating a biocide into an SE polymer without changing the surface energy of the polymer. However, in these static raft trials, the polymers were not suited to withstand the heavy marine fouling challenge.