Making PVA-Based Antimicrobial Food Packaging Film: An Incorporated Association with AgNPs-Immobilized Cellulose Nanospheres

Abstract

As the most universal biopolymer, nanocelluloses have been emerged with distinctive features such as biodegradability, renewability, non-toxicity and applicable feasibility in large-scale industry. In an effort to diversify the practical application of such natural origin materials, the surface modifications of nanocelluloses based on hydroxyl groups have been widely addressed. In the context of metal nanoparticles loaded on nanocelluloses, such above-mentioned modifications required complicated multiple-step procedures and used external toxic reagents, limiting their applications in humans. The aim of this study reported a simple and eco-friendly chemical approach in immobilizing silver nanoparticles (AgNPs) on corn leaf-derived nanocellulose using non-toxic reagents. Taking into account the native surface hydroxyl groups of nanocellulose in its dispersing in water and favouring the immobilization of metal nanoparticles, the nanospheres were obtained with a mean diameter of 22.5 nm as proven via transmission electron microscopy (TEM), the exclusive presence of crystalline AgNPs was evidenced via X-ray diffraction (XRD), and the Ag percentage of 4.1 % was explored on the surface via energy-dispersive X-ray (EDX). The complete antimicrobial performances against E. coli and S. aureus were achieved within 6 h. The findings of this work were achieved in a green context, widening a preliminary trial in strawberry packaging; for example, a PVA-based film blended with 2 % AgNPs-immobilized cellulose nanospheres remained strawberries intact and no appearance of microorganisms.