Synthesis of clay–TiO₂ nanocomposite thin films with barrier and photocatalytic properties for food packaging application

Abstract

In this study, low-density polyethylene (LDPE) nanocomposite films with two types of nanoparticles, TiO 2 (3 wt %) and Closite 20A (3 and 5 wt %), were prepared using a melt blow extrusion as an industrial method and their properties such as mechanical properties, water vapor, oxygen and carbon dioxide gas barrier, and antimicrobial activity were tested. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were also performed to determine the degree of dispersion and exfoliation of nanoparticles. Mechanical test indicated that the reinforcement in the presence of the nanocomposites was more than that with their conventional counterparts, and the highest stiffness was achieved in a sample containing 5 wt % clay and 3 wt % TiO 2 . Exfoliation of silicate layers and a good dispersion of TiO 2 nanoparticles in LDPE were achieved as confirmed by XRD and TEM. The gas barrier properties were improved after formation of the nanocomposites especially by insertion of 5 wt % of clay nanoparticles as a filler in the LDPE matrix. The photocatalytic effect of the nanocomposite film was carried out by antimicrobial evaluation against Pseudomonas spp. and Rhodotorula mucilaginosa and by ethylene removal test using 8 W ultraviolet (UV) lamps with a constant relative intensity of 1 mW cm 22 . The greatest effects were recorded by combining UVA illumination and active film. It was also proven that the photocatalyst thin film with improved barrier properties prepared by extrusion could be used in horticultural product packaging applications.

Investigation of developed clay‐nanocomposite packaging film on quality of peach fruit ( Prunus persica Cv. Alberta) during cold storage

“…The method for developing clay nanocomposite PE‐based film (5% nanoclay) with specific physicochemical properties was reported in the work of Bodaghi, Mostofi, Oromiehie, Ghanbarzadeh, and Ghasimi Hagh (). In this study, Water Vapor Transmission Rate (WVTR) was measured with a tester, model L80–500, equipped with a very sensitive and reliable humidity sensor, directly located in the measuring chamber to control temperature and relative humidity.…”

“…The method for developing clay nanocomposite PE-based film (5% nanoclay) with specific physicochemical properties was reported in the work of Bodaghi, Mostofi, Oromiehie, Ghanbarzadeh, and Ghasimi Hagh (2015). In this study, Water Vapor Transmission Rate (WVTR)…”

Nanostructured Antimicrobials in Food Packaging—Recent Advances

“…When incorporated into chitosan films, titanium oxide nanoparticles (TiO 2 NPs) made them active against G(−) and Gram‐positive (G(+)) bacteria as well as fungi, extending microbial stability of grapes . The photocatalytic activity of TiO 2 NPs was explored not only for antimicrobial purposes, but also for ethylene scavenging effects, which is useful to delay ripening of climacteric fruits. Migration studies indicated no detectable Ti in bread (food model) after a 6‐month contact with soybean polysaccharide films containing up to 7% TiO 2 NPs…”

Protection of high‐density polyethylene–silicon composites from ultraviolet–visible photodegradation

“…The control of the effects of oxidation by the incorporation of light‐blocking additives is key to the protection of the chemical structure of the polymer and in the design of materials to ensure long‐term properties . The protection of polymers against UV–vis photoirradiation is still a current issue, despite the extended use of organic and inorganic UV blockers .…”