Design, development and first validation of “biocide-free” anti-fouling coatings

This method was used to prepare amphiphilic, as well as fully hydrophilic and hydrophobic systems, which were spray coated on construction steel samples. The coating wettability was analysed on all samples through the measurement of wetting hysteresis, highlighting the amphiphilic behaviour of the formulations. The highest amphiphilic character was detected on the hydrophilic reference sample, probably due to the highest mobility of PEG-ilate chains under this configuration. Anti-fouling properties were determined by the evaluation of the retention rate of two alive Mediterranean marine organisms, Mytilus Edulis and Ulva Intestinalis, on the surface of samples. A further test was carried out to evaluate the AF/FR properties against a natural protein probe, namely egg white. The test carried out with natural organisms proved the suitability of all the proposed strategies to the implementation of effective AF/FR marine paints. The egg white test assessed that the highest efficiency in AF/FR activity was detained by the fully hydrophobic systems. The observation of the surface of the samples by SEM in back scatter modality revealed that the chemical patterning of the hydrophobic scenario could play a significant role in the development of such behaviour.