English abstract
Biofouling is the unwanted accumulation and attachment of marine micro- and macro organisms in any surfaces submerged in seawater. Biofouling is known by its deteriorating effects on the surfaces it form on, thus, lots of efforts were given to find solutions for this problem. However, due to the environmental impacts caused by common used toxic antifoulants, there is a big demand to search for novel non-toxic methods for prevention of biofouling such as fouling-release antifouling coatings technology and nanotechnology-based antifouling coatings. The main aim of this study was to investigate the efficiency of using the fouling-release silicone-based coating Hempel Hempasil X3 as well as the nanotechnology-based zinc oxide (Zno) nano coatings as novel coatings for biofouling prevention. The antifouling performance of the Hempasil X3R was tested in field experiment for 10 months at Marina Bandar Rawdah and Marina Shangri La and its toxicity was tested and compared to a standard toxic copper-based coating in lab experiment using Artemia salina larvae. Our results showed good antifouling performance of Hempasil X3® in both marinas with better results at Marina Shangri La. Also, Hempasil X3R was not toxic compared to the copper based coating. The ZnOnano-coatings were prepared in laboratory by hydrothermal, synthesis method using two seeding solutions (5 and 10mM) and two nanorods growing methods (conventional and microwave). Four ZnOnano-coatings, in total, were prepared (5mM conventional, 10mM conventional, 5mm microwave and 10mm microwave) and their photocatalytic antifouling properties were tested in lab experiment using antibacterial (using Acinetobacter sp. AZ4C), antilarval (using Bugula neriting and Artemia salina larvae) and antialgal (using Tetraselmis sp.) bioassays under light and dark conditions. All ZnO nano-coatings showed good antifouling activity against the above mentioned organisms under light condition but not in dark. So, our findings show that Hempel Hempasil X3® coating is a promising non-toxic and efficient antifouling coating which could be used as alternative for biocidal ones. Also, Zno nano-coatings exhibited good antifouling activities and this can be further investigated and exploited as new approach for biofouling prevention.
