Migration of titanium dioxide from PET/TiO2 composite film for polymer-laminated steel

Strong Photochemical Activity of Colored Microplastics Containing Cadmium Pigments: Mechanisms and Implications

Plastics used in daily life are often colored for esthetic and functional purposes. Nevertheless, little is known about the photochemical activity of colored microplastics and the associated risks that are ubiquitous in the environment. In this study, we report the strong photochemical activity of microplastics colored with cadmium pigments. These colored microplastics can be excited by photons within the solar spectrum (<514 nm), readily generating •OH, O2•-, and H2O2. Consequently, they can effectively degrade 17β-estradiol, achieving >91% degradation within 23 h under simulated solar exposure. Among microplastics colored with different cadmium pigments, those with a cadmium pigment S/Se ratio of 2:5 exhibited the highest photoactivity. This is attributed to the narrow band gap, fast charge separation, and efficient charge transfer of the microplastics, as suggested by the energy band, photocurrent, and electrochemical impedance results. Meanwhile, hazardous Cd2+ was leached from colored microplastics mainly owing to the oxidation of pigment lattices by photogenerated holes. Our results reveal that microplastics colored with photoactive inorganic pigments behave drastically differently from uncolored counterparts. This highlights the importance of considering pigments as a critical factor for better assessing the environmental fate and risks of colored microplastics and plastic products.

Assessment of TiO2 (nano)particles migration from food packaging materials to food simulants by single particle ICP-MS/MS using a high efficiency sample introduction system

TiO2 is the most widely used white pigment in plastics and food packaging industry, thus the question of its migration towards food and hence the impact on consumers is raised. Since recent research indicate its potential toxicity, it is necessary to study TiO2 contamination as a consequence of food storage. For this purpose, plastic containers from commercially-available dairy products and custom-made TiO2-spiked polypropylene materials were put in contact with 50% (v/v) ethanol and 3% (w/v) acetic acid, which were used here as food simulants. The migration assays were carried out under standard contact conditions of packaging use (as recommended by Commission Regulation (EU) N° 10/2011 for food contact migration testing), and under conditions of extreme mechanical degradation of the packaging. The TiO2 (nano)particles released in the food simulants were analysed by single particle inductively coupled plasma-tandem mass spectrometry in mass-shift mode and using a high efficiency sample introduction system (APEX™ Ω) to avoid matrix effects from food simulants. For the dairy product containers and for the spiked polypropylene, results showed release of TiO2 particles of rather large sizes (average size: 164 and 175 nm, respectively) under mechanical degradation conditions, i.e. when the polymeric structure is damaged. The highest amounts of TiO2 were observed in 50% ethanol after 10 days of storage at 50 °C (0.62 ng cm-2) for the dairy product containers and after 1 day of storage at 50 °C (0.68 ng cm-2) for the spiked polypropylene. However, the level of Ti released in particle form was very small compared to the total Ti content in the packaging and far below the acceptable migration limits set by European legislation. Release under standard contact conditions of use of the container was not measurable, thus the migration of TiO2 particles from this packaging to dairy products among storage is expected to be negligible.

Thermal and Mechanical Characterization of the New Functional Composites Used for 3D Printing of Static Mixers

This paper investigates the possibility of integrating the combination of nanofillers, titanium dioxide (TiO₂) and carbon nanotubes (CNT) into the thermoplastic polymer matrix. This combination of fillers can possibly modify the physico-chemical properties of composites compared to the pure polymer matrix. The composites were blended using the extrusion method. The composite filament produced was used to manufacture static mixers on a 3D printer using the additive manufacturing technology fused filament fabrication (FFF). The aim of this work was to inspect the influence of the filler addition on the thermal and mechanical properties of glycol-modified polyethylene terephthalate (PET-G) polymer composites. The fillers were added to the PET-G polymer matrix in several ratios. Tensile test results showed an increase in the overall strength and decrease in the elongation at break of the material. Melt flow rate (MFR) showed a decrease in the viscosity with the initial filler addition and reaching a plateau after 2 wt% filler was added. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed minor changes in the thermal properties. Scanning electron microscope (SEM) results showed homogenous distribution of the filler in the matrix and strong filler-matrix adhesion. The results indicate suitable properties of new functional composites for the 3D printing of static mixers for application in tubular reactors.

Migration of Irganox 1010, Irganox 1076, and Titanium dioxide into Doogh and corresponding food simulant from laminated packaging

PURPOSE

Doogh is a famous Iranian drink based on fermented milk. Laminated film is one of the most common packaging for this beverage in Iran. So, chemical substances of the packaging may migrate to the Doogh and endanger human health.

METHOD

In this research, High-Performance Liquid Chromatography (HPLC) was used to determine the migration of Irganox 1010 and Irganox 1076 from the contact layer and inductively coupled plasma for Titanium dioxide (TiO2) from the second layer of three-layer laminate films into Doogh and acetic acid 3% (w/v). The influence of different storage temperatures and times was investigated by evaluating the samples stored in various conditions. The morphological, thermal and mechanical properties of the film, before and after contact with food simulant were further studied.

RESULT

The highest amount of Irganox 1010 concentration of the tested samples were 0.8 ± 0.04 mg/l in acetic acid 3% (w/v), and 0.62 ± 0.04 mg/l in Doogh. The highest amount of TiO2 concentration were 0.25 ± 0.04 mg/l in acetic acid 3% (w/v), and 0.12 ± 0.02 mg/l in Doogh. The migration of Irganox 1076 was determined, but it was not detected. The results indicated that the food simulant had no significant effect on the microstructure and thermal properties of the polymer, but it reduced the mechanical properties.

CONCLUSION

The results indicate the possible migrating of Irganox 1010 and TiO2 through laminate packaging into Doogh in some storage conditions. Since the migration value was low, the mentioned film was proven safe for Doogh packaging, imposing no hazards on human health.

Antioxidant and cell-friendly Fe2TiO5 nanoparticles for food packaging application

An emerging technology of active packaging enables prolongation of food shelf life by limiting the oxygen transfer and the reactivity of free radicals, which both destruct food freshness. In this work, Fe₂TiO₅ nanoparticles were synthesized using a modified sol-gel method and evaluated as an enforcement of alginate food packaging film. Pure phase Fe₂TiO₅ nanoparticles had an average particle size of 44 nm and rhombohedral morphology. Fe₂TiO₅ nanoparticles induce no cell damage of human Caco-2 epithelial cells and show no inhibitory effect towards growth of a panel of bacterial strains, suggesting good biocompatibility. Films obtained by incorporation of Fe₂TiO₅ nanoparticles into alginate using the solvent casting method show no migration of iron or titanium ions from films to food simulants again suggesting their safety as a packaging material. Fe₂TiO₅ nanoparticles also showed strong antioxidant efficiency as determined using the DPPḢ assay, and confirmed further in a preservation test on fresh fruit.

Titanium dioxide nanoparticles as multifunctional surface-active materials for smart/active nanocomposite packaging films

Environmental issues such as plastic packaging and high demand for fresh and safe food has increased the interest for developing smart/active food packaging films with colloidal nanoparticles (NPs). Titanium dioxide nanoparticles (TNPs) are cost effective and stable metal oxide NPs which could be used as a functional nano-filler for biodegradable food packaging due to their excellent biocompatibility, photo catalyzing, and antimicrobial properties. This article has comprehensively reviewed the functional properties and advantages of TNPs-containing smart/active films. The advantage of adding TNPs for ameliorating food packaging materials such as their physical, mechanical, moisture/light barrier, optical, thermal resistance, microstructure and chemical properties as well as, antibacterial, and photocatalytic properties are discussed. Also, the practical and migration properties of administrating TNPs in food packaging material are investigated. The ethylene decomposition activity of TNPs containing active films, could be used for increasing the shelf life of fruits/vegetables after harvesting. TNPs are safe with negligible migration rates which could be used for fabrication of multifunctional smart/active packaging films due to their antimicrobial properties and ethylene gas scavenging activities.

Recent advances and challenges on applications of nanotechnology in food packaging. A literature review

Nanotechnology applied to food and beverage packaging has created enormous interest in recent years, but in the same time there are many controversial issues surrounding nanotechnology and food. The benefits of engineered nanoparticles (ENPs) in food-contact applications are accompanied by safety concerns due to gaps in understanding of their possible toxicology. In case of incorporation in food contact polymers, the first step to consumer exposure is the transfer of ENPs from the polymer to the food. Hence, to improve understanding of risk and benefit, the key questions are whether nanoparticles can be released from food contact polymers and under which conditions. This review has two main goals. Firstly, it will presents the current advancements in the application of ENPs in food and beverage packaging sector to grant active and intelligent properties. A particular focus will be placed on current demands in terms of risk assessment strategies associated with the use ENPs in food contact materials (FCMs), i.e. up-to-date migration/cytotoxicity studies of ENPs which are partly contradictory. Food matrix effects are often ignored, and may have a pronounced impact on the behaviour of ENPs in the gastrointestinal tract (GIT). A standardized food model (SFM) for evaluating the toxicity and fate of ingested ENPs was recently proposed and herein discussed with the aims to offer an overview to the reader. It is therefore clear that further systematic research is needed, which must account for interactions and transformations of ENMs in foods (food matrix effect) and in the gastrointestinal tract (GIT) that are likely to determine nano-biointeractions. Secondly, the review provides an extensive analysis of present market dynamics on ENPs in food/beverage packaging moving beyond concept to current industrial applications.