Improving energy efficiency of ships by modifying hull surface via coating Cu NPs *

Antifouling is an important research challenge in marine tribology. Since ships are permanently exposed to an aqueous environment, their hulls are prone to fouling. With the increase of time, the ship hull surface will be covered by a dense layer of firmly attaching organisms such as barnacles, mussels and seaweeds. These layers strongly increase the drag and reduce the fuel efficiency. Copper nanoparticles possess excellent antifouling performance. In this study, in situ generation of Cu NPs on the surface of dopamine modified 304 stainless steel in weak alkaline aqueous solution was reported. Field emission scanning electron microscope, contact angle measurement and x-ray photoelectron spectroscopy were utilized to analyze the chemical composition and surface wettability of the modified stainless steel. The results demonstrated that the surface of stainless steel was coated with polydopamine and Cu NPs successfully. Antibacterial assay showed that modified surface possessed the ability of resistance of Vibrio natriegens. The presence of copper offers the coatings excellent capability to inhibit effectively the adhesion of marine algae Phaeodactylum tricornutum. This strategy exhibited a realistic paradigm for further improving the antifouling performances of hull surfaces.