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

Abstract

In this study, CuMt and TiMt montmorillonites were produced via an ion-exchange process with Cu+ and Ti4+ ions. These nanostructured materials were characterized with X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) measurements and added as nanoreinforcements and active agents in chitosan (CS)/poly-vinyl-alcohol (PVOH)-based packaging films. The developed films were characterized by XRD and FTIR measurements. The antimicrobial, tensile, and oxygen/water-barrier measurements for the evaluation of the packaging performance were carried out to the obtained CS/PVOH/CuMt and CS/PVOH/TiMt films. The results of this study indicated that CS/PVOH/CuMt film is a stronger intercalated nanocomposite structure compared to the CS/PVOH/TiMt film. This fact reflected higher tensile strength and water/oxygen-barrier properties. The antibacterial activity of these films was tested against four food pathogenic bacteria: Escherichia coli, Staphylococcus aureus, Salmonella enterica and Listeria monocytogenes. Results showed that in most cases, the antibacterial activity was generated by the CuMt and TiMt nanostructures. Thus, both CS/PVOH/CuMt and CS/PVOH/TiMt films are nanocomposite candidates with very good perspectives for future applications on food edible active packaging.

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

“…Water vapor diffusion coefficient through films (D WV ) was calculated following Fick’s law principles and according to Equation (3), the derivation of which was described in detail in our previous publication [ 28 ]. where D WV (cm 2 · s −1 ) is the diffusion coefficient, WVTR (g · cm −2 · s −1 ) is the water vapor transmission rate, Δx (cm) is the mean film thickness, and ΔC (g · cm −3 ) is the humidity concentration gradient in the two opposite sides of the film, which in our case is 22.86747 g · cm −3 according to the calculations reported in our previous publication [ 28 ].…”

“…The OTR value of each kind of film was the mean value of measurements on three pieces. The origination of Equation (4) is described in detail in our previous publication [ 28 ]. where Pe O2 (cm 2 · s −1 ) is the oxygen permeability coefficient through films, OTR (cm 3 · m −2 · s −1 ) is the measured oxygen transmission rate, and Δx (cm) is the mean film thickness.…”

“…In the last decade, much effort has been devoted to developing nanocomposite films based on CS/Mt [ 15 , 16 , 17 , 18 , 19 , 20 ] and CS/HNT [ 11 , 12 , 21 , 22 , 23 , 24 , 25 ] for food packaging and drug delivery applications. Recently, polyvinyl alcohol (PVOH) was added to a CS/Mt matrix, acting as an effective plasticizer and enhancing the barrier properties [ 26 , 27 ] as well as the antimicrobial properties [ 28 ].…”

Performance of Thyme Oil@Na-Montmorillonite and Thyme Oil@Organo-Modified Montmorillonite Nanostructures on the Development of Melt-Extruded Poly-L-lactic Acid Antioxidant Active Packaging Films

“…Table 3 lists the measured Water Vapor Transmission Rate (WVTR) and Oxygen Transmission Rate (OTR) values as well as the calculated water vapor diffusion coefficient (DWV) and oxygen permeability coefficient (PeO2) values. Water vapor diffusion coefficient values (DWV) and oxygen permeability coefficient values (PeO2) were calculated according to Fick law, oxygen permeability through polymers equation, and assumptions described in [28]. According to this literature, we can calculate the water vapor diffusion coefficient D (cm 2 •s −1 ) for every film as follows:…”

“…Experimental conditions were fixed at 38 • C and 50% RH according to the ASTM E96/E96M-05 method. Using a handmade apparatus and following the methodology described extensively in a previous publication [30] and modified recently [22,28], WVTR measurements were carried out. For such measurements, film disks of 2.5 cm diameter and 100 µm thickness were used.…”