On the mechanism of marine fouling-prevention performance of oil-containing silicone elastomers.

For many decades, silicone elastomers with oil incorporated have served as fouling-release coating for marine applications. In a comprehensive study involving a series of laboratory-based marine fouling assays and extensive global field studies of up to 2-year duration, we compare polydimethylsiloxane (PDMS) coatings of the same composition loaded with oil via two different methods. One method used a traditional, one-pot pre-cure oil addition approach (o-PDMS) and another method used a newer post-cure infusion approach (i-PDMS).

Sewage sludge ash-based mortar as construction material: Mechanical studies, macrofouling, and marine toxicity.

Incinerated sewage sludge ash is tested here as a cement and aggregate substitute in mortar blocks. It can be used at various percentages to reduce the overall cost of production and promote ash recycling. The compressive strength of the cast blocks was tested at 28 days to determine the optimal combination of ball milled ash (replacing cement) and sewage sludge ash (replacing sand).

Removal of larvae of two marine invasive bivalves, Mytilopsis sallei (Récluz, 1849) and Mytella strigata (Hanley, 1843), by water treatment processes.

The uptake and discharge of bivalve larvae through ballast water operations is a highly viable mechanism for transfer of shellfish. In this paper, we investigate the effects of common water treatment processes on the planktotrophic larvae of the two invasive species of shellfish, Mytilopsis sallei and Mytella strigata. The study found that common water treatment processes used in many ballast water treatment systems were effective for the removal of bivalve larvae, although later stages of larval forms required more effort to remove.

Effect of Variations in Micropatterns and Surface Modulus on Marine Fouling of Engineering Polymers.

We report on the marine fouling and fouling release effects caused by variations of surface mechanical properties and microtopography of engineering polymers. Polymeric materials were covered with hierarchical micromolded topographical patterns inspired by the shell of the marine decapod crab Myomenippe hardwickii. These micropatterned surfaces were deployed in field static immersion tests.

Managing the risk of non-indigenous marine species transfer in Singapore using a study of vessel movement.

Shipping is recognized as a major vector for the global transfer of non-indigenous marine species (NIMS). As a major transshipment port, Singapore can minimize the risk of NIMS transfer by implementing pragmatic management strategies, such as using vessel movement information to assess the risk of NIMS transfer. Findings from vessel movement information in a major port terminal in Singapore showed that vessel residence time is short, with >92% of vessels spending seven days or less.

Fouling-Release Performance of Silicone Oil-Modified Siloxane-Polyurethane Coatings.

The effect of incorporation of silicone oils into a siloxane-polyurethane fouling-release coatings system was explored. Incorporation of phenylmethyl silicone oil has been shown to improve the fouling-release performance of silicone-based fouling-release coatings through increased interfacial slippage. The extent of improvement is highly dependent upon the type and composition of silicone oil used.

Comparison of laboratory and field testing performance evaluations of siloxane-polyurethane fouling-release marine coatings.

A series of eight novel siloxane-polyurethane fouling-release (FR) coatings were assessed for their FR performance in both the laboratory and in the field. Laboratory analysis included adhesion assessments of bacteria, microalgae, macroalgal spores, adult barnacles and pseudobarnacles using high-throughput screening techniques, while field evaluations were conducted in accordance with standardized testing methods at three different ocean testing sites over the course of six-months exposure. The data collected were subjected to statistical analysis in order to identify potential correlations.

Biomimicking micropatterned surfaces and their effect on marine biofouling.

When synthetic materials are submerged in marine environments, dissolved matter and marine organisms attach to their surfaces by a process known as marine fouling. This phenomenon may lead to diminished material performance with detrimental consequences. Bioinspired surface patterning and chemical surface modifications present promising approaches to the design of novel functional surfaces that can prevent biofouling phenomena.