Development of ZnO/Na-Montmorillonite Hybrid Nanostructures Used for PVOH/ZnO/Na-Montmorillonite Active Packaging Films Preparation via a Melt-Extrusion Process

Abstract

Nowadays, the shelf-life extension of foods is a topic of major interest because of its environmental and economic benefits. For this purpose, various methods like deep-freezing, ultra-high-temperature pasteurization, drying methods, use of chemicals, controlled-atmosphere preservation, ionizing irradiation, and were investigated. During the last years, the smart packaging for foods using natural biodegradable components is of great interest because it provides positive environmental fingerprint and high shelf-life extension. In the present work, a new nanostructured composite material, the ZnO/Na-Montmorillonite hybrid, was developed. The high antimicrobial properties of the 3-D ZnO material in combination with the high barrier and strength properties of the 2-D Na-Montmorillonite material provided a high promising component for food smart packaging applications. As an extra innovation of this process, the ZnO nanorods coated the external surface of the Na-Montmorillonite and it was not intercalated into the clay as a pillaring material. This new material was incorporated with a 3% w/w composition with a biodegradable poly(vinyl)alcohol (PVOH) polymeric matrix which also exhibits antimicrobial activity. The final product was tested via XRD, FTIR, SEM, tensile test, water sorption, water vapor permeability, oxygen permeability UV–vis, and anti-microbial activity tests and it exhibited advanced mechanical and antimicrobial properties, especially for a ZnO/Na-Montmorillonite fraction of 4:1.

Nanocomposite Film Development Based on Chitosan/Polyvinyl Alcohol Using ZnO@Montmorillonite and ZnO@Halloysite Hybrid Nanostructures for Active Food Packaging Applications

“…The use of ZnO/clay nanostructures for photocatalytic applications is well known in the literature [ 37 ]. Recently, a growing interest was raised [ 38 , 39 ] for the development and application of such ZnO/clay nanostructures and their use as active food packaging materials. According to this simple and innovative idea, the ZnO is expected to act either as an antimicrobial or reinforcement agent, and nanoclays are expected to act as both a reinforcement and a barrier agent [ 39 ].…”

“…Recently, a growing interest was raised [ 38 , 39 ] for the development and application of such ZnO/clay nanostructures and their use as active food packaging materials. According to this simple and innovative idea, the ZnO is expected to act either as an antimicrobial or reinforcement agent, and nanoclays are expected to act as both a reinforcement and a barrier agent [ 39 ]. Ding et al [ 38 ] prepared palygorskite@ZnO nanorods and loaded different contents into chitosan-based films.…”

“…In a recent study [ 39 ], novel ZnO@Mt hybrid nanostructures, similar to one of the two reported in this study, were developed to achieve a novel nanofiller with enhanced tensile, barrier, and antimicrobial properties. Detailed structural characterization was carried out in this study, including SEM images.…”

Effect of Copper and Titanium-Exchanged Montmorillonite Nanostructures on the Packaging Performance of Chitosan/Poly-Vinyl-Alcohol-Based Active Packaging Nanocomposite Films

“…Experiments were carried out at 38 °C and 50% RH. The methodology was described extensively in the literature [ 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. The 2.5 cm diameter and 0.09 mm average thickness film was placed on the top of a one-open end cylindrical tube made of plexiglass which contained dried silica gel inside and was sealed by a rubber O-ring.…”

Biodegradable Antimicrobial Food Packaging: Trends and Perspectives

“…[ 50 , 51 , 52 ], oxide nanoparticles (ZnO, TiO 2 , CuO, etc.) [ 53 , 54 , 55 ], clay nanoparticles (cloisite, montmorillonite, bentonite) [ 56 , 57 , 58 ], natural extracts (essential oils or hydrophilic extracts) [ 59 , 60 , 61 ], natural antimicrobials (nisin, pediocin, antibiotics, etc.) [ 62 , 63 , 64 ], biopolymers (chitosan) [ 65 , 66 , 67 ], enzymes (lysozyme, peroxidase) [ 68 , 69 , 70 ], synthetic antimicrobial agents (including synthetic antibiotics) [ 71 ].…”