In this study, the properties of poly (vinyl alcohol) (PVA) films incorporated with Zataria multiflora essential oil (ZMO) as a potential antioxidant/antibacterial material was investigated. PVA films were prepared from PVA solutions (2% w/v) containing different concentrations of ZMO. Water solubility, moisture absorption, water swelling, and water vapor permeability for pure PVA films were 57 ± 1.1, 99 ± 3.2%, 337 ± 8%, and 0.453 ± 0.015 g mm/m2 h, respectively. Incorporation of ZMO into PVA films caused a significant decrease in water swelling and moisture absorption and increase in solubility and water vapor permeability. Tensile strength, elastic modulus, and elongation at break for pure PVA films were 13.5 ± 0.61 MPa, 15.2 ± 0.8 MPa, and 216 ± 4%, respectively. Incorporation of ZMO into the PVA films caused a significant decrease in tensile strength and elastic modulus and increase in elongation at break of the films. Pure PVA film showed UV‐visible light absorbance ranging from 280 to 440 nm with maximum absorbance at 320 nm. Addition of ZMO caused a significant increase in light absorbance and opacity. PVA films exhibited no antioxidant and antifungal activities, whereas PVA/ZMO films exhibited excellent antioxidant and antifungal properties. Although the bioactivity PVA films were improved by the addition of ZMO, however, the mechanical properties and water binding capacity of the films were weaken slightly. Thus, ZMO emulsified in the ethanol not compatible with PVA matrix and more suitable emulsifier was needed in order to obtain strong film with higher mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40937.

Gelatin composite films were prepared from gelatin solutions (10% w/v) containing multi-walled carbon nanotubes (MWCNT, 0.5, 1, 1.5, and 2% w/w gelatin) as nanofiller. The water solubility, water swelling, water uptake, water vapor permeability (WVP), mechanical, and antibacterial properties of the films were examined. Water solubility, water swelling, water uptake, and WVP for gelatin films were 45 ± 1%, 821 ± 42%, 45 ± 1.1%, and 0.4 ± 0.022 g mm/m2 kPa h, respectively. Incorporation of MWCNT caused a significant decrease in water solubility, water swelling, water uptake, and WVP. Gelatin/MWCNT films containing 1–1.5% MWCNT showed the lowest water vapor transmission. Tensile strength, elongation at break, and Young's modulus for gelatin films were 13.4 ± 1.2 MPa, 95 ± 5%, and 45.4 ± 7 MPa, respectively. Incorporation of MWCNT caused a significant increase in tensile strength and decrease in the elongation at break. The largest mechanical strength was found at 1.5% MWCNT. All gelatin/MWCNT films showed significant antibacterial activities against both gram-positive and gram-negative bacteria. Our results suggest that the gelatin/MWCNT composites films could be used as a very attractive alternative to traditional materials for different biomedical and food applications.

Polyvinyl alcohol (PVA) thin films were reinforced by glutaraldehyde and multiwalled carbon nanotubes (MWCNTs) and then mechanical, water solubility, water swelling, water uptake, water vapor permeability, and antibacterial properties of the films were examined. Cross‐linking by glutaraldehyde or incorporation of MWCNT caused a significant increase in tensile strength, decrease in elongation at break, and increase in Young's modulus of the PVA films, while MWCNTs were more effective rather than that of glutaraldehyde. Cross‐linking by glutaraldehyde or incorporation of MWCNT caused a significant decrease in water solubility, water swelling and water uptake, with a similar manner. Cross‐linking by glutaraldehyde or incorporation of MWCNT caused a significant increase in the light absorbance, while maximum absorbance was at 400 nm. Only PVA/MWCNT films but no PVA/glutaraldehyde showed significant antibacterial activities in a dose‐dependent manner against both Gram‐positive and Gram‐negative bacteria. Thus, noncovalent improvement by MWCNT was more effective on the PVA thin films rather than covalent cross‐linking by glutaraldehyde. Our results suggest that the PVA/MWCNT composites films could be used as a very attractive alternative to traditional materials for different biomedical and food applications. POLYM. COMPOS., 35:1736–1743, 2014. © 2013 Society of Plastics Engineers

In this article, oxygen barrier properties of nanocomposite films composed of organoclay (OC), high‐density polyethylene (HDPE), and ethylene vinyl acetate (EVA) copolymer have been investigated. The nanocomposite films whose EVA forms a dominant fraction were prepared using the solution method. The dispersion of the OC in the HDPE/EVA blend was improved through taking two‐step procedure in the preparation of nanocomposite. First, the OC and EVA were dissolved in chloroform. Then, the resulting product, after evaporating most of the solvent, along with HDPE was dissolved in xylene. The obtained nanocomposite films underwent a number of tests in order to examine their barrier properties including X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that OC/HDPE/EVA nanocomposites are intercalated and partially exfoliated. Furthermore, from the TEM micrographs, the organoclay experimental aspect ratio was found. Also, the O2 permeability through the films was evaluated, which showed that adding both OC and HDPE to EVA leads to a remarkable increase in the barrier properties of EVA films. Finally, by using the gas permeation results and existing permeation theories, the organoclay theoretical aspect ratio was predicted. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers