Estudo do comportamento térmico de nitrilotriacetatos de alguns metais de transição.
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Data
2021-02-15
Autores
Silva, Bruna Cesar Campos Sena
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O ácido nitrilotriacético é um agente quelante que tem a possibilidade de ligação a uma ampla série de íons metálicos: mono, bi ou trivalentes. Neste trabalho foram obtidos os nitrilotriacetatos de alguns metais da primeira série de transição (Co, Ni, Cu e Zn), por meio da reação direta entre a suspensão aquosa dos carbonatos metálicos e solução saturada do ácido nitrilotriacético. Ao se concluir a reação e como forma de garantia da não contaminação do ácido, deixou-se um pequeno excesso de carbonato, filtrando-se o mesmo no final. A fase aquosa foi lentamente evaporada por aquecimento, até próximo à secura. Posteriormente foi colocada em dessecador a vácuo, sob ação de cloreto de cálcio como secante, até massa constante. As amostras foram caracterizadas por Espectroscopia IV, Difração de Raio-X, Termogravimetria (TG) e Análise Térmica Diferencial (DTA). Por meio da Análise Térmica pode-se determinar a estequiometria dos compostos obtidos, observando-se também as bandas de estiramento através da Espectroscopia IV comparando-se com as bandas padrões de água e do ácido nitrilotriacético puro, por fim, analisou-se as etapas de decomposição de cada composto.
Nitrilotriacetic acid is a chelating agent that has the possibility of binding to a wide range of metal ions: mono, bi or trivalent. In this work, nitrilotriacetates of some metals from the first transition series (Co, Ni, Cu and Zn) were obtained, through the direct reaction between the aqueous suspension of the metallic carbonates and a saturated solution of nitrilotriacetic acid. Upon completion of the reaction and as a way of ensuring that the acid was not contaminated, a slight excess of carbonate was left, filtering it at the end. The aqueous phase was slowly evaporated by heating, until close to dryness. Subsequently, it was placed in a vacuum desiccator, under the action of calcium chloride as a drying agent, until constant mass. The samples were characterized by IR Spectroscopy, X-ray diffraction, Thermogravimetry (TG), Differential Thermal Analysis (DTA). Through the Thermal Analysis, the stoichiometry of the obtained compounds can be determined, also observing the stretch bands through the Spectroscopy IV comparing with the standard bands of water and pure nitrilotriacetic acid, finally, the steps were analyzed through the decomposition of each compound.
Nitrilotriacetic acid is a chelating agent that has the possibility of binding to a wide range of metal ions: mono, bi or trivalent. In this work, nitrilotriacetates of some metals from the first transition series (Co, Ni, Cu and Zn) were obtained, through the direct reaction between the aqueous suspension of the metallic carbonates and a saturated solution of nitrilotriacetic acid. Upon completion of the reaction and as a way of ensuring that the acid was not contaminated, a slight excess of carbonate was left, filtering it at the end. The aqueous phase was slowly evaporated by heating, until close to dryness. Subsequently, it was placed in a vacuum desiccator, under the action of calcium chloride as a drying agent, until constant mass. The samples were characterized by IR Spectroscopy, X-ray diffraction, Thermogravimetry (TG), Differential Thermal Analysis (DTA). Through the Thermal Analysis, the stoichiometry of the obtained compounds can be determined, also observing the stretch bands through the Spectroscopy IV comparing with the standard bands of water and pure nitrilotriacetic acid, finally, the steps were analyzed through the decomposition of each compound.
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Palavras-chave
Análise térmica., Ácido nitrilotriacético., Metais de transição., Nitrilotriacetatos metálicos., Thermal analysis, Nitrilotriacetic acid, Transition metals, Metallic nitrilotriacetates