Evaluation of Anti-Fouling Behavior of Silver Nanocomposites Made by Nano-Coating Fragmentation

Nano-coating fragmentation (NCF) is patented technology which allows producing thermoplastic matrix nanocomposites without the step of nanoparticle preparation. Thermoplastic pellets are PVD (physical vapor deposition) coated by the metal of the desired nano-reinforce. In the following processing step, by extrusion or injection molding, nano-coatings are fragmented into nanoplatelets because of the action of the screw. In this study, nano-silver (Ag) filled nanocomposites with polypropylene (PP) matrix have manufactured by this innovative technique and tested in open environment for their anti-fouling behavior. PP pellets have been PVD coated into a large chamber with the aid of a rotating drum. Coated pellets were physically mixed with virgin in the percentage of 0, 5, 10, 20, and 100%. Consequently, the expected Ag percentage ranged from 0.036% wt to 0.103% wt. Square nanocomposite samples (80x80 mm 2 and 3 mm thick) were injection molded in a fully electric press. One sample for each nano-Ag content was selected to be exposed in open environment. A smart buoy, especially designed for water cleaning and monitoring, has been used for experimentation. Results show that Ag-NPs provide a significant contribution to reduce the growth of vegetation on the molded plastic surfaces. However, at very low contents, the negative effect of the Ag NPs on the surface morphology of the molded samples nullifies this contribution.