The synthesis of nano-silver/polypropylene plastics for antibacterial application

Ammonium persulfate/ferric nitrate mixtures were used in this study to modify the hydrophobic surface of polypropylene (PP) with allowing hydrophilic oxygen-containing functional groups to grow. In-situ synthesis method was then employed to optimize Ag/PP composite materials by performing different experimental parameters. In addition, another new synthesis process, called heat-softening method, was adopted for comparison. The surface characteristics of modified PP using FTIR-ATR, TEM, SEM and XPS analysis have revealed the differences by the parameters as changed. Finally, Escherichia coli and Staphylococcus aureus were chosen as the target bacteria to evaluate the efficacy of using the Ag/PP composite materials for disinfection purpose. In order to better understand the repeatability of Ag/PP composite for disinfection, consecutive disinfection tests have been carried out in our experiment. However, it was found the silver content on the Ag/PP became less compared to the original one and the disinfection rate also decreased. After heat-softening synthesis was introduced in this research, it was found that silver atoms could be better anchored onto the surface of PP substrate and the disinfection efficiency would not become worse after repeated disinfection, which has also been demonstrated by the inhibitory loop analysis.