Diatom attachment inhibition: limiting surface accessibility through air entrapment

Abstract

Surfaces consisting of sub micron holes (0.420-0.765 μm) engineered into nanoparticle (12 nm) coatings were examined for marine antifouling behaviour that defines early stage settlement. Immersed surfaces were found to be resistant to a 5-hour attachment assay of Amphora coffeaeformis, a marine organism commonly found in abundance on fouled substrates such as foul-releasing paints and self-polishing coatings. Attachment inhibition was attributed to the accessibility of diatoms to the surface. This was governed by the size and morphology of trapped interfacial air pockets measured in-situ using synchrotron small angle x-ray scattering. Surfaces containing larger pores (0.765 μm) exhibited the highest resistance. Macroscopic wettability via contact angle measurements however remained at 160° and sliding angle of < 5° and was found to be independent of pore size and not indicative of early stage fouling behaviour. The balance of hierarchical nano/micro length scales was critical in defining the early stage stability of biofouling character of the interface.

Changes in Coastal Benthic Algae Succession Trajectories and Assemblages Under Contrasting Nutrient and Grazer Loads

“…Microstructures play a crucial role in diatom attachment (e.g. Wu et al 2013), which consequently alter the benthic assemblage composition at later successional stages (Schneck et al 2011). Accordingly, in our study we observed strong substrate specific differences, with Cocconeis dominating in the smoother microsubstrate surfaces, where its firmly attachment mode presents a greater resistance to the drag forces of the flow (Gari and Corigliano 2007).…”

Potentiodynamic study of Al–Mg alloy with superhydrophobic coating in photobiologically active/not active natural seawater

“…At a given pattern wavelength the interaction with the surfaces is species specific, and, for diatoms smaller than surface grooves attachment is more efficient [54,55]. Submicron geometrical patterns of SH surfaces do not influence the attachment, making the presence of trapped air decisive, so that the effect of fouling hindrance is proportional to the size of trapped air bubbles [56]. In our case, the size of attaching diatoms is comparable with the large-scale level of the SHc hierarchical structure (1-5 m valleys and hills), with respect to which the removal of trapped air can encourage attaching phenomena.…”

Engineered Antifouling Microtopographies: An Energetic Model That Predicts Cell Attachment

“…The most recent literature has attempted to define a mechanism of antifouling. Configuration 7,8,9,10 , aspect ratio 11 , and feature size 12,13 are variables that have been identified. However, the relative importance of each and the mechanisms through which the different topographical characteristics control attachment has thus far proved to be elusive.…”