Silver-titanium polymeric nanocomposite non ecotoxic with bactericide activity

In view of the intense interest in applications of silver nanoparticles in products for the medical field and in food preservation packaging due to their antimicrobial properties, the ecotoxicology of silver nanocomposites was evaluated in films. Test with the sea urchin Echinometra lucunter, to evaluate embryonic development and contamination by the action of silver and titanium nanoparticles in polyethylene nanocomposite films presents new results. The silver nanoparticle's stability in polymeric materials can be enhanced by adding carriers, such as titanium dioxide and montmorillonite clay (MMT) without to producing one unfriendly material. For this research, low-density polyethylene (LDPE)/linear low-density polyethylene (LLDPE) were used processed in a twin-screw extruder, followed by gamma irradiation with 25 kGy and characterized by ecotoxicology assays, field emission scanning electron microscopy (FESEM), scanning electron microscopy and energy dispersive spectroscopy (SEM-EDX), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), Raman spectroscopy (SERS) and mechanical properties. The antibacterial properties of the LDPE films were investigated against Escherichia coli and Staphylococcus aureus. The gamma irradiation had an important effect in the synthesis of silver nanoparticles resulting in bactericidal activity and the death of 100% of the tested bacteria. The evaluation of the environment was considered with the ecotoxicological investigation carried out. The results indicated that the polymeric films with silver nanoparticles and TiO₂ do not contaminate the environment and neither interfere with the larval development of Echinometra lucunter. The obtained materials can be used in various applications with antimicrobial properties.