TATIANA SANTANA BALOGH
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Resumo IPEN-doc 27327 Synthesis and characterization of PVP nanogels prepared by gamma radiation using 60Co source2019 - BALOGH, T.S.; KADLUBOWSKI, S.; BONTURIM, E.; VARCA, G.; LUGAO, A.B.Nanogels are promising and innovative systems in nanometer scale, with particle size range varying from 0 to 100 nm, of great potential in nanomedicine, pharmaceutics and bionanotechnology. They present several advantages such as capacity of injection into the circulation reaching target tissues and ability to deliver their payloads locally and intracellularly. Nanogels are defined as two-component system on nanometer scale consisting of a permanent three-dimensional network of linked polymer chains, and molecules of a solvent filling the pores of this network. They are formed by intramolecular crosslinking that can be achieved by the use of ionizing radiation, this method allows the formation of nanogels free of additives, rendering them non-toxic, a fundamental requirement for biomedical application. In this work, five samples of nanogels were developed using a 25 mM PVP solution. The samples were saturated with argon and prepared in multipurpose cobalt-60 gamma irradiator using doses of 1, 2, 5, 10 and 25 kGy at a dose rate of 10 kGy/hour corresponding, respectively, to samples A, B, C, D and E. These samples were morphologically characterized using atomic force microscopy (AFM) as well as the pristine PVP solution. The mean particle size of the samples as well as the determination of polydispersity index was performed in equipment Zetasizer Nano ZS - Malvern® and the determination of radius of gyration and molecular weight was realized in equipment Heleos - Wyatt®. The mean particle size of the samples A, B, C, D and E, were, respectively, 41.89, 46.85, 61.04, 62.79 and 62.11 nm and the mean particle size of the pristine PVP solution was 43.28 nm. The AFM results revealed the presence of spherical nanostructures in the samples prepared with dose equal to or more than 5 kGy (samples C, D and E). Under the conditions evaluated in the study the morphological characterization of the nanogels revealed that the doses of 5 kGy, 10 and 25 kGy are the most suitable doses for the nanogel formation as it led to spherical structures when compared to the other conditions assayed.Artigo IPEN-doc 24142 Recovery of 131I from fission 99Mo production process by distillation method2017 - DAMASCENO, MARCOS O.; BALOGH, TATIANA S.; FORBICINI, CHRISTINA A.L.G. de O.The results of one of the recovery stages of 131I as a byproduct of the 99Mo fission production process are presented in this work. A modified wet-distillation apparatus was used for iodide purification and some work parameters were tested. The assays included iodide anion eluent, concentration of H2SO4, H2O2, the catalyst effect of MoO3, temperature and time process. The results of eluting anions demonstrated lower recovery of 131I using nitrate salt. The sulfate solution and its respective acid (H2SO4) at concentration 1.6 M, presented better results. Hydrogen peroxide was used as a main oxidant of the ions iodide, the experiments realized with 6 mL of H2O2 3% showed higher recovery than assays prepared with H2O2 higher and lower amount. Molybdenum oxide was evaluated as catalyst of iodine in solution; however, the results did not demonstrate an advantage in relation to its absence. In addition, the recovery of iodide was delayed at initial periods of the process in presence of the catalyst, leading to an increase on time process. Temperature decrease of distillation solution from 80 to 50 °C showed advantageous since the recovery yields were similar beside a lower wet drag to trap solution. Time distillation was carried out at least four hours with sampling each hour; the best times were between 1 and 2 hours. Shorter periods of distillation avoid dilution of the capture solution on the further recovery process. Several parameters were studied and it was possible to set up system that provided 131I recovery around 50% yield.