%0 Generic
%A Cao, Xinyu
%D 2008
%F heidok:8876
%K Meeresorganismen , Adhäsion , Oberflächenanalytik , Polyelektrolyt Multilagen , Oberflächenchemiemarine organism , adhesion , surface analysis , polyelectrolyte multilayers , surface chemistry
%R 10.11588/heidok.00008876
%T Antifouling Properties of Smooth and Structured Polyelectrolyte Thin Films
%U https://archiv.ub.uni-heidelberg.de/volltextserver/8876/
%X The goal of this thesis is the development of smooth and structured polyelectrolyte surfaces and to correlate the surface properties with their antifouling performance. Strategies in antifouling are focused on two aspects: surface chemistry and surface topography. Therefore, two types of surfaces, polysaccharide coatings with different chemistries and poly(acrylic acid)/polyethylenimine multilayers with different topographies, have been studied in this thesis. Three polysaccharides, hyaluronic acid (HA), alginic acid (AA) and pectic acid (PA), were covalently coupled on glass or silicon surfaces. The results of protein adsorption tests on these coatings indicate that surface charge, molecular conformation and reaction with calcium play important roles in the interactions between polysaccharides and proteins. The settlements of bacteria (Pseudomonas fluorescens, Vibrioalginolyticus, Cobetia marina and Marinobacter hydrocarbonoclasticus ), algae (Navicula perminuta and Ulva linza) and invertebrate cyprids (Balanus amphitrite) on polysaccharide coatings reveal that surface properties such as wettability, swelling in water and interactions with ions have great influence on biofouling. Polyelectrolyte multilayers were applied to study the effect of topography on marine biofouling. These multilayers were constructed by the deposition of the oppositely charged polyelectrolytes, poly(acrylic acid) (PAA) and polyethylenimine (PEI) through a layer-by-layer spray coating method. Hierarchical surface structures with different texture sizes and roughnesses were obtained by adjusting the pH of the polyelectrolyte solutions. Settlement of Ulva spores and barnacle cyprids was remarkably reduced by the multilayers with large texture size and high roughness. The effect of topography on biofouling is related to the attachment points between the surface and the fouling organisms. Surface modifications on polyelectrolyte multilayers with fluorinated silane and poly(ethylene glycol) (PEG) combined topography and chemistry. The antifouling performance of modified multilayers was determined by both the topography of the multilayer film and the chemistry of the surface.   Several techniques were applied to analyze the surface properties of the coatings, including contact angle measurement, spectral ellipsometry, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM).