Biofouling, the undesired colonization of surfaces, is a major
problem for marine-related industries. To prevent unwanted effects caused by
biofouling, suitable non-toxic coatings for the marine environment are required.
Conditioning, i.e. the adsorption of proteins and macromolecules influences, as
surface chemistry and morphology do, the settlement of fouling oragnisms. Investigating
the temporal dynamics of conditioning film formation on functionalized
self assembled monolayers (SAMs), it was shown that the obtained film thickness
of about 10Å to 20Å is independent of the surface chemistry but differences
occur concerning the composition of these films. While on hydrophilic surfaces
more proteinaceous compounds are detectable, the hydrophobic surfaces show a
lower intensity of proteins. Furthermore, is was shown that in standard Ulva linza
spore settlement assays the influence of a molecular conditioning layer is likely
to be small, but by increasing pre-conditioning time this influence gains importance
and should be considered in long term experiments. Preconditioning also
resulted in detectable surface differences in field studies. It was found that preconditioned
samples which contain more proteinaceous compounds seem to be more
attractive for settlement. Experiments with matured laboratory biofilms formed
by Pseudomonas aeruginosa demonstrated that using a protein-rich medium results
in conditioning film formation. Conversely, surface conditioning is reduced
when a media containing a smaller amount of proteins is utilized. Furthermore,
it was observed that surface chemistry has no remarkable effect on the fraction
of inoculated bacteria that adhere to a surface.
Finally, inspired by the nanostructured skin of dolphins, electron-beam lithography
was utilized to create a honeycomb topography made of poly(N-isopropylacrylamide)
(PNIPAM). The evaluation showed that structures from 0.75 μm to
2.5 μm in diameter reduce Ulva settlement in comparison to a smooth PNIPAM
surface. It should be noted, that wet polymer structure heights in the range of
only 0.01 μm do have an effect on spores with a body size of around 5 μm