DEQUI - Trabalhos apresentados em eventos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/602
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Resultados da Pesquisa
Item Spectrofluorimetric determination of second critical micellar concentration of SDS and SDS/Brij 30 systems.(2009) Romani, Ana Paula; Machado, Antonio Eduardo da Hora; Hioka, Noboru; Severino, Divinomar; Baptista, Mauricio da Silva; Codognoto, Lúcia; Magini, Maira Regina Rodrigues; Oliveira, Hueder Paulo Moisés dePotentially useful stead-state fluorimetric technique was used to determine the critical micellar concentrations (CMC1 and CMC2) for two micellar media, one formed by SDS and the other by SDS/Brij 30. A comparative study based on conductimetric and surfacial tension measurements suggests that the CMC1 estimated by the fluorimetric method is lower than the value estimated by these other techniques. Equivalent values were observed for SDS micelles without Brij 30 neutral co-surfactant. The use of acridine orange as fluorescent probe permitted to determine both CMC1 and CMC2. Based on it an explanation on aspects of micelle formation mechanism is presented, particularly based on a spherical and a rod like structures.Item Nanomagnetism and domain structure of sintered nickel-zinc ferrites studied by magnetic force microscopy.(2004) Dias, AndersonThe nanomagnetic structure of hydrothermal NiZn femtes sintered at various temperatures was studied in this work through Magnetic Force Microscopy using different magnetically characterized tips. The magnetic patterns varied according to the tip employed and were correlated to the magnetic induced field generated by these different coated tips. Nickel fenites were produced at 200°C by hydrothermal synthesis and sintered at temperatures ranging from 1100°C to 1400°C.