Innovative films by embedding magnetic nanoparticles in cellulose acetate
Lisandra de Castro Alves, Miguel A. Cerqueira, Manuel A. González‐Gómez, Pelayo García‐Acevedo, Ángela Arnosa Prieto, Yolanda Piñeiro, Lorenzo Pastrana, J. Rivas
Abstract
Magnetic nanoparticles (MNPs) with different magnetic, physical, and chemical properties can be used to develop magnetic tags, offering a unique traceability capability that can then be used to improve products’ safety. In this work, synthesized MNPs were incorporated into a cellulose acetate (CA) matrix and characterized in their pristine form and when incorporated in the films. Results show that MNPs are different in composition, morphology, size, and magnetic response. Afterwards, iron carbide (Fe5C2), hexagonal-shaped (Fe3O4 @OA) and multicore magnetite (m-Fe3O4) nanoparticles (NPs) were embedded within the CA matrix showing and good distribution in the films’ matrix. Nevertheless, magnetic films with 0.1 wt% of Fe5C2 NPs (FM1), and m-Fe3O4 NPs (FM4) offered a more uniform dispersion of the NPs over the CA matrix. Incorporating MNPs does not affect the films' mechanical properties and water sensitivity. Nevertheless, the optical properties of the films were affected with high impact for the films with m-Fe3O4 NPs. Particularly for magnetic tagging, the CA films displayed similar magnetic responses to their respective bulk NPs, showing their potential as anti-counterfeiting tags for food packaging applications.