Eloi Alves da Silva Filho

Quantificação de antimônio em garrafas de politereftalato de etileno (PET) brasileiras por fluorescência de raios-X e avaliação quimiométrica para verificar a presença de pet reciclado através do teor de ferro

Antimony is a common catalyst in the synthesis of polyethylene terephthalate used for food-grade bottles manufacturing. However, antimony residues in final products are transferred to juices, soft drinks or water. The literature reports mentions of toxicity associated to antimony. In this work, a green, fast and direct method to quantify antimony, sulfur, iron and copper, in PET bottles by X-ray fluorescence spectrometry is presented. 2.4 to 11 mg Sb kg-1 were found in 20 samples analyzed. The coupling of the multielemental technique to chemometric treatment provided also the possibility to classify PET samples between bottle-grade PET/recycled PET blends by Fe content.

Interaction of Ion Iron(II) with Polyaniline Observed by Infrared Spectroscopy, X-ray and Mössbauer Spectroscopy

This study investigated the interaction of Fe(II) ions with esmeraldine salt form of polyaniline (PANI -ES). Treatment of the aniline with ammonium persulfate in an acidic medium generated the polymer, which was doped with iron ion through the addition of the salt Fe(NH4)2(SO4)2·6H2O in amounts equimolar a room temperature. Xray diffraction, infrared and Mossbauer spectroscopies were used to characterize the doped polymer. Through the set of spectroscopic results it was possible to confirm the formation of PANI-Fe (II) complex and that these ions interacted with the benzenoids nitrogen atoms of the polymer chain.