Equilíbrio de fases de sistemas aquosos bifásicos compostos por polietilenoglicol, sulfato de zinco, sulfato de cobre e citrato de sódio sob diferentes temperaturas

• Ano de defesa: 2006
• Autor(a) principal: Oliveira, Rosana Moura de
• Orientador(a): Coimbra, Jane Sélia dos Reis
• Banca de defesa: Minim, Luis Antonio , Fontes, Maurício Paulo Ferreira , Rojas, Edwin Elard Garcia , Oliveira, Maria Cristina Bevitóri Maffia de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Sistemas aquosos bifásicos; Dados de equilíbrio; Temperatura
• Palavras-chave em Inglês: Aqueous two-phase systems; Phase equilibrium; Temperature
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/2929

This work presents the study of aqueous two-phase systems containing by polymers polyethyleneglycol (PEG), inorganic salts and water. Polymers used had two different molecular weights, PEG 1500 g.mol-1 and PEG 4000 g.mol-1. The salts that composed the biphasic systems were zinc sulphate, copper sulphate and sodium citrate. Systems with PEG 1500 + sodium citrate were analyzed at (10, 35 and 45) °C, while systems PEG 4000 + zinc sulphate or copper sulphate were studied at the temperatures (5, 10, 35 and 45) °C. The systems composed by sodium citrate + PEG 4000 were studied at the same temperature as zinc or copper sulphate and also at 25 °C. The effect of temperature on the binodal curve was analyzed being observed an increase in the biphasic area in the PEG 4000 + copper sulphate and PEG 4000 + sodium citrate systems. However, in zinc sulphate systems this behavior was observed only from (5 to 25) °C, being observed a small reduction from (35 to 45) °C. It was not observed an expansion in the biphasic area with an increase in temperature for the PEG 1500 + sodium citrate system. In general, there was an increase in the tie line slope with an increase in the temperature. The effect of molar mass of polymer was investigated for polyethyleneglycol 1500 and 4000, being observed an increase in the biphasic area with an increasing in polymer molar mass at 35 °C. Salt effect was investigated in the systems containing PEG 4000 and salts zinc sulphate and copper sulphate, being observed a larger biphasic area for the system containing sulphate copper.