Influence of silver, tin, and Ag-Sn nanoalloy on the physicochemical characteristics and migration behavior into food simulants of LDPE packaging films

In this study, LDPE active packaging films (ANFs) were produced by incorporating 1% Ag, Sn nanoparticles, and an Ag-Sn nanoalloy, and comprehensive characterization analyses were conducted. TGA results revealed that the addition of Sn nanoparticles, in particular, led to a significant increase in film thermal stability. In contrast, the Ag nanoparticles and Ag-Sn nanoalloy additions showed limited changes compared to the control film. FTIR analyses demonstrated that the additives successfully integrated into the polymer matrix and provided structural compatibility without introducing new functional groups. SEM and elemental distribution maps confirmed that the nanoparticles were homogeneously distributed on the surface. The Ag and Sn nanoparticles additions caused minimal changes in color parameters, while the Ag-Sn nanoalloy caused a slight decrease in the L* value. In migration analyses, low-level migration was observed from Ag nanoparticles-containing ANFs in aqueous and ethanolic food simulants, whereas Sn nanoparticles-containing ANFs migrated only in acetic acid. No measurable migration was detected in Ag-Sn nanoalloy-containing ANFs. These results demonstrate that the alloy form, in particular, offers the safest and most stable structure for food contact materials. Overall, the findings indicate that Ag-Sn nanoalloy-containing LDPE films are a potential active packaging material, exhibiting high performance in both thermal and migration aspects.