Gas chromatography–mass spectrometry determination of the migration of phthalate plasticisers from polyvinyl chloride in food aliments

In this study, the specific migration of epoxidized sunflower oil (ESO) and di-octyl phthalate (DOP) was addressed by using gas chromatography coupled with mass spectrometry. The test conditions were 12 days. Twelve circular samples of plasticized PVC were immersed in 120 ml of olive oil and aqueous ethanol. A circular sample and 10 ml of food simulant were taken off every day to be analyzed. The rate of mass variation was followed. We first searched for the optimum operating conditions for the analysis of additives in question (ESO and DOP) in based on the measurement of retention time to increase the sensitivity and specificity of the chromatographic system chosen.Keywords: plasticized PVC, migration, DOP, ESO, CG/SM

An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling

Over the last 60 years plastics production has increased manifold, owing to their inexpensive, multipurpose, durable and lightweight nature. These characteristics have raised the demand for plastic materials that will continue to grow over the coming years. However, with increased plastic materials production, comes increased plastic material wastage creating a number of challenges, as well as opportunities to the waste management industry. The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances (known as “additives”) contained in all plastic products for enhancing polymer properties and prolonging their life. Despite how useful these additives are in the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in literature and described herein. These additives can potentially migrate and undesirably lead to human exposure via e.g. food contact materials, such as packaging. They can, also, be released from plastics during the various recycling and recovery processes and from the products produced from recyclates. Thus, sound recycling has to be performed in such a way as to ensure that emission of substances of high concern and contamination of recycled products is avoided, ensuring environmental and human health protection, at all times

Вплив нагрівання газу і RF потужності розпилення на електричні, структурні та оптичні властивості тонких плівок ITO

У роботі пропонується дослідити вплив нагрівання газу та RF потужності розпилення на електричні, структурні та оптичні властивості тонких плівок оксиду індію для застосувань у сонячних елементах. Ці тонкі плівки готували на слаболегованій кремнієвій пластині методом RF-розпилення у середовищі Ar при кімнатній температурі і тиску 8·10 – 3 мбар. Параметри процесу, такі як RF потужність і відпал після осадження, змінювалися для того, щоб визначити їх залежність від електричних, структурних і оптичних властивостей тонких плівок ITO. Морфологію та вимірювання товщини шару (з поперечним перерізом) досліджували методом скануючої електронної мікроскопії, а для визначення шорсткості поверхні застосовували атомну силову мікроскопію. Залежність питомого опору, рухливості та концентрації носіїв цих плівок досліджували за допомогою ефекту Холла шляхом зміни RF потужності та термічного відпалу. Спектроскопічна еліпсометрія також використовувалася для визначення показника заломлення, товщини, шорсткості, пористості та оптичної ширини забороненої зони плівок. Таким чином, оптичний коефіцієнт пропускання у видимій області виявився вище 85 %; низький питомий опір і висока рухливість становили, відповідно, 2.09·10 – 4 Ом·см і 35.81 см2/(V·s) для товщини зразка 200 нм, RF потужності 150 Вт, і відпалу при 400 °С протягом 10 хв при швидкому термічному відпалі під дією N2. Рентгенівська дифракція тонких плівок показала кращу орієнтацію вздовж напряму (222), яка забезпечує високу ступінь кристалічності для всіх відпалених N2 зразків. Рентгенівська фотоелектронна спектроскопія використовувалася для визначення станів окислення та елементного вмісту у плівках. Представлені результати морфології поверхні, електричні та оптичні властивості плівки ITO.In the paper we propose to investigate the effect of the annealing gas and RF power sputtering on the electrical, structural and optical properties of indium tin oxide thin films for solar cells applications. These thin films were prepared on lightly doped silicon wafer by RF sputtering in Ar environment at room temperature and with a pressure of 8·10 – 3 mbar. Process parameters such as RF power and post deposition annealing were varied in order to determine their dependence on electrical, structural and optical properties of ITO thin films. Layer morphology and thickness measurements (with cross section) were investigated by scanning electron microscopy, and atomic force microscopy was performed to determine the surface roughness. The dependence of the resistivity, mobility and carrier concentration of these films by varying RF power and thermal annealing were studied by Hall Effect measurement. Spectroscopic ellipsometry was also used to determine the refractive index, thickness, roughness, porosity and optical bandgap of the films. Thus, the optical transmittance in the visible region was found to be above 85 %, the low resistivity and high mobility were found 2.09 10 – 4 Ω·сm and 35.81 cm2/(V·s), respectively, for 200 nm thickness for the sample elaborated with a RF power of 150 W and an annealing at 400 °C for 10 min with rapid thermal annealing under N2. The X-ray diffraction patterns of the thin films indicated a preferred orientation along the (222) plane, which provides a high degree of crystallinity for all N2 annealed samples. The XPS was used to determine oxidation states and identify the elemental content in the films. Obtained results for the surface morphology, electrical and optical properties of the ITO thin film details will be presented

Fast growth of pure V

Vanadium pentoxide (V2O5) nanorods were successfully grown through an easy, quick and clean hydrothermal method using vanadium oxide sols (V2O5.1,6H2O) as precursor. Structurals studies based on the X-ray diffraction and Raman spectroscopy revealed that the synthesized nanomaterials are pure divanadium pentoxide with an orthorhombic phase. The morphological properties and the particle size of the developed V2O5 nanoparticles were investigated by scanning electron microscopy (SEM) and high resolution transmission electron microscope (HRTEM). The results show that the as-grown samples consist of a large amount of one-dimensional V2O5 nanorods with the widths approximately 52 nm and the lengths are up to several hundred nanometers. The effects of different growth conditions, such as hydrothermal duration and stirring temperature of the precursor on the formation of the nanorods has been recorded. Moreover, the structural and morphological properties of the resulting nanopowders have been experimentally studied. Time-dependent experiments showed that V2O5.1,6H2O were dehydrated progressively and transformed into orthorhombic V2O5 single-crystalline nanorods. It has been established that high stirring temperature of the precursor is benefical for the formation of V2O5 nanorods and minimizes the duration time of the heat treatment. Hence the adjusted parameters (time and temperature) appears to be the key element to achieving the desired nanomaterial with defined forms

Soil Burial Degradation of New Bio-Based Additives. Part I. Rigid Poly(vinyl chloride) Films

International audienceCommercial sunflower oil was epoxidized, and the epoxidized sunflower oil (ESO) was used as a thermal stabilizer for poly(vinyl chloride) (PVC). Rigid formulations stabilized with ESO as a new stabilizer and epoxidized soybean oil (ESBO) as a commercial stabilizer for comparison were prepared. The aging of the PVC samples was investigated in landfill soil for 24 months. The structure modifications of the polymer were followed by Fourier transform infrared spectroscopy (FTIR). Furthermore, the variations of density and mechanical properties (tensile and Shore D hardness) were considered. The variations of the mass of the samples, the glass transition temperature (T(g)), the molar mass distribution, and the weight loss were followed as a function of time of soil burial. The soil burial test showed the loss of additives by migration and biodegradation that led to the modification of density, mechanical properties, molar mass distribution, and weight loss of the PVC samples