Tailored design of Cu2O nanocube/silicone composites as efficient foul-release coatingsElectronic supplementary information (ESI) available. CCDC 73304. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ra01597a

Environmental concerns about the use of toxic antifoulants have increased the demand to develop novel, environmentally-friendly antifouling materials. Silicone coatings are currently the most effective non-toxic alternatives. This study focused on developing a model for silicone foul-release nanocomposites that were successfully designed, fabricated, characterized, and tailored toward foul-release (FR) coatings. A series of elastomeric polydimethyl-siloxane (PDMS)/Cu 2 O nanocube composites with different nanofiller concentrations was successfully synthesized, for the first time, as FR coatings via solution casting technique. Emphasis was given to the study of the physicomechanical and surface properties, as well as the easy release efficiency of the elastomer PDMS enriched with Cu 2 O nanocubes. The bulk properties of the nanocomposites appeared unchanged after adding low amounts of nanofillers. By contrast, surface properties such as contact angle and surface free energy were improved, and the settlement resistance and easy release behavior of the nanocomposites were enhanced. The surfaces were further proven to have reversible tunable properties and are thus renewable in water. The antifouling property of the nanocomposites was investigated by laboratory assays involving microfoulants such as Gram-positive and Gram-negative bacteria, as well as yeast organisms, for 30 days. Exposure tests showed that lower surface energy and elastic modulus of coatings resulted in less adherence of marine microfouling. The most profound effect recorded was the reduction of fouling settlement with nanofiller loadings of up to 0.1% Cu 2 O nanocubes. Thus, the good foul release and long-term durability confirmed that the present strategy was an attractive nontoxic and environmentally-friendly alternative to the existing antifouling systems. Environmental concerns about the use of toxic antifoulants have increased the demand to develop novel, environmentally-friendly antifouling materials.