Influence of surface morphology on the adhesion of marine organisms
M.P. Arpa Sancet,
X. Cao, F. Wode, A. Rosenhahn, M. Grunze
Applied Physical Chemistry, University of Heidelberg, Germany
Understanding the response of marine organisms to different surface
properties is an important prerequisite for the development of improved
antifouling coatings. Besides surface chemistry, the topography of surfaces is
known to influence adhesion of fouling organism. As in nature many surfaces developed
a topography in the micrometer- or nanometer range, the goal of the presented
work is to prepare bioinspired surface morphologies and to systematically vary their
size centered around the one found in nature. By evaluating the response of
selected marine organisms, structure sizes with effect on the target fouling
organisms are identified. The synthetic polyelectrolyte multilayers are constructed
by the deposition of oppositely charged polyelectrolytes through layer-by-layer
deposition. Hierarchical surface structures with different texture sizes and
roughnesses were obtained by adjusting the preparation conditions. A
modification of the obtained surfaces is achieved by the application of
organosilanes by CVD or from solution. Ulva assays revealed that settlement and
adhesion strength is significantly affected by texture size and surface
chemistry. Interestingly, even for surfaces with resistant surface chemistries,
the morphological influence can still be observed. At present we extend the
experiments towards adhesion strength of marine bacteria. This is done by
exerting a variable shear stress to adherent bacteria and quantification of the
cell number by light microscopy. Ethylene glycol containing self assembled monolayers
(SAMs) with different hydration are used as first benchmark system to prove the
applicability of the new microfluidic setup.