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.

Marine antifouling from thin air

“…The collection and culture of A. reticulatus followed the methods in Vucko et al (2014). Briefly, brood stock of A. reticulatus, grown on polyvinylchloride plates, was collected from the Townsville Yacht Club (TYC; Townsville, QLD, Australia) and transported with natural seawater to James Cook University (JCU; Townsville, QLD, Australia) where they were fed Chaetoceros muelleri (Lemmermann 1898; CS-176) and maintained in a temperature-controlled room at 28°C under a 12 h light:12 h dark photoperiod.…”

“…Attachment point theory describes surface-organism interactions as a function of the relative contact area present at the water/surface interface where a reduction in the number of attachment points accessible on a substratum leads to reduced attachment strength and lower permanent settlement rates (Carl et al 2012). Hence, the manufacture of topographies to prevent fouling is typically based on the smallest dimension of the targeted fouling organisms, which can range over several orders of magnitude, from bacteria (~4 μm) and algal spores (~10 μm), to tubeworm larvae (~130 μm), barnacle cyprids (~180 μm) and bryozoan larvae (~320 μm) (Scardino et al 2006(Scardino et al , 2008Vucko et al 2014). Unfortunately, the deterrent effect of these surfaces can also be diminished when exposed to a natural fouling community where conditioning and overgrowth occurs by organisms too small or too large to be affected by a given surface size (Vucko et al 2014).…”

“…These include chemically engineered surfaces such as superhydrophilic, zwitterionic (Jiang & Cao 2010) and amphiphilic coatings (eg Chen et al 2011;Zhou et al 2014), as well as morphologically engineered surfaces (Schumacher et al 2007;Long et al 2010;Scardino & de Nys 2011;Carl et al 2012;Vucko et al 2014). Chemically engineered surfaces have shown promise (Vucko et al 2013), while morphologically engineered surfaces have also demonstrated AF efficacy in laboratory assays (Schumacher et al 2007;Carl et al 2012;Vucko et al 2014), and the results may be explained by attachment point theory (Scardino et al 2006(Scardino et al , 2008. Attachment point theory describes surface-organism interactions as a function of the relative contact area present at the water/surface interface where a reduction in the number of attachment points accessible on a substratum leads to reduced attachment strength and lower permanent settlement rates (Carl et al 2012).…”

“…Hence, the manufacture of topographies to prevent fouling is typically based on the smallest dimension of the targeted fouling organisms, which can range over several orders of magnitude, from bacteria (~4 μm) and algal spores (~10 μm), to tubeworm larvae (~130 μm), barnacle cyprids (~180 μm) and bryozoan larvae (~320 μm) (Scardino et al 2006(Scardino et al , 2008Vucko et al 2014). Unfortunately, the deterrent effect of these surfaces can also be diminished when exposed to a natural fouling community where conditioning and overgrowth occurs by organisms too small or too large to be affected by a given surface size (Vucko et al 2014). A possible environmentally friendly attachment-inhibiting alternative lies in the use of physical barriers such as air.…”

Towards integrated anti-microbial capabilities: Novel bio-fouling resistant membranes by high velocity embedment of silver particles

“…Recently developed strategies to reduce bio-fouling include the decoration or surface patterning of the membrane surface to induce catalytic degradation of both carbon feedstocks and bio-foulants prior to their surface adhesion [19][20][21]. Routes to incorporate catalytic materials include nano-particle impregnation [22], chemical anchoring [23], mixing within the polymer matrix during membrane synthesis [24] or growth from metal salts in solution [25].…”