Development of antibacterial silver treatments on HDPE nets for agriculture

The defense mechanism of crops associated with the use of polymeric nets and fabrics is only physical and, hence, ineffective against the bacterial contaminations. The presence of an antibacterial agent associated with the use of conventional agro-textiles can represent a great advantage in the prevention of plant diseases and for food safety. The aim of this work was the development of antibacterial silver-coated HDPE nets for an innovative application such as agriculture. Antibacterial coatings on high-density polyethylene nets were obtained by a patented nanosilver deposition technique based on the in situ photo-reduction of a silver solution. The concentration of silver deposited was defined by testing different silver solutions from a biological point of view. Moreover, in order to improve the adhesion of the silver coating to the substrate, the nets underwent low-pressure plasma treatment before the silver deposition. The materials were characterized in terms of quality of the coating through scanning electron microscopy, and in terms of antibacterial capability on Gram positive and Gram negative bacteria through qualitative and quantitative microbiological tests. The most effective process parameters were defined and the importance of performing plasma pretreatment on this specific substrate was assessed.